TWI467103B - Pneumatic cylinder device - Google Patents

Description

Pneumatic cylinder device

The present invention relates to a pneumatic cylinder device.

In the pneumatic cylinder device, there is a form in which a pressurized gas is sealed inside. In this type of pneumatic cylinder device, lubrication of the piston rod and the sealing member sliding the piston rod must be performed. For example, there is a configuration in which a lubricating oil is immersed in an impregnating member (for example, see JP-A-2002-372087).

In the above-described pneumatic cylinder device, there is a possibility that airtightness cannot be maintained.

The present invention provides a pneumatic cylinder device that can maintain airtightness.

According to a first aspect of the present invention, a pneumatic cylinder device includes: a pneumatic cylinder in which an operating gas is sealed, and at least one end thereof is an opening; a piston slidably inserted into the pneumatic cylinder; and the piston is coupled to the pneumatic cylinder a piston rod protruding outwardly; and a rod guide provided on one end side of the pneumatic cylinder. Between the piston and the rod guide: an annular sealing member sliding with the piston rod; a sliding member axially slidably disposed in the pneumatic cylinder between the sealing member and the piston; and A lubricant retaining chamber in which a lubricant is sealed between the sliding member and the sealing member. The sealing member or the sliding member is provided with a discharge mechanism that discharges residual gas remaining in the lubricant holding chamber during assembly.

The discharge mechanism is provided in the sliding member to form a communication between the lubricant holding chamber and the pneumatic cylinder.

The discharge mechanism is provided on an inner circumference or an outer circumference of the sliding member, and constitutes a front end by a lip extending toward the piston side.

According to a second aspect of the present invention, the sliding member is formed of a sliding portion formed of a soft material that is in sliding contact with the inner circumference of the pneumatic cylinder and the piston rod, and a material that is harder than the sliding portion. The non-sliding portion is formed. The piston rod is provided with a restriction means for restricting the movement of the sliding member in the axial direction. When the restricting means abuts against the sliding member, the restricting means abuts against the non-sliding portion.

The air cylinder may be formed with a movement restricting means for preventing the restriction means from abutting against the sliding member after assembly.

The discharge mechanism may be constituted by a discharge path that discharges the residual air, and a closing mechanism that closes the discharge path.

The discharge passage may be provided in the sealing member to form a communication between the lubricant holding chamber and the rod guide.

The occluding mechanism may be an annular plate that is held between the sealing member and the rod guide.

The closing mechanism may be provided integrally with the sealing member.

A sealing means may be provided between the rod guide and the pneumatic cylinder.

According to the pneumatic cylinder device described above, airtightness can be maintained.

"First embodiment"

The pneumatic cylinder device according to the first embodiment of the present invention is a gas spring. The gas spring of this embodiment will be described below with reference to Figs. 1 to 5 .

As shown in Fig. 1, the gas spring of the first embodiment includes a pneumatic cylinder 12, a piston 13, a piston rod 14, a rod guide 15, and a mounting bracket 16. The pneumatic cylinder 12 is formed in a slightly closed cylindrical shape with one end open. The compressed gas G as an operating gas is sealed in the pneumatic cylinder 12. The piston 13 is slidably inserted into the pneumatic cylinder 12. The piston rod 14 protrudes outward from the one end opening side of the pneumatic cylinder 12 coupled to the piston 13. The rod guide 15 is an end opening guide piston rod 14 provided in the pneumatic cylinder 12. The mounting bracket 16 is fixed to the outside of the other end of the pneumatic cylinder 12. Further, the operating gas may be other gases such as nitrogen or helium.

The pneumatic cylinder 12 is made of metal. The air cylinder 12 is an opening 22 that is one end in the axial direction of the tubular portion 21 that does not close the tubular shape, and is configured to close the other end of the flange portion 21 in the axial direction by the lid portion 23. The crotch portion 21 is mainly composed of a cylindrical portion 25 having a constant diameter. In the crotch portion 21, an annular opening-side locking portion 26 having a smaller diameter than the cylindrical portion 25 is formed at an end portion on the opening portion 22 side. Further, in the crotch portion 21, an annular annular convex portion (movement restricting means) 27 that forms a smaller diameter than the cylindrical portion 25 is formed in the intermediate portion in the axial direction. Thereby, the cylindrical portion 25 is divided into the opening-side cylindrical portion 28 between the opening-side locking portion 26 and the annular convex portion 27; and the cover-side cylindrical portion between the annular convex portion 27 and the lid portion 23 29. Further, the pneumatic cylinder is not made of metal, and may be made of resin.

The lid portion 23 has a substantially spherical shape that is convex toward the opposite side of the crotch portion 21. Inserted in the center of the lid portion 23 along the axial direction of the jaw portion 21 Into the hole 30. Further, the pneumatic cylinder 12 is formed by forming the flange portion 21 and the lid portion 23 by other members, and the joint portion is formed by the integration. However, the flange portion 21 and the lid portion 23 may be integrally formed by one material.

The mounting bracket 16 is made of metal. The mounting bracket 16 has a flat plate-shaped joint plate portion 35, a flat plate-shaped mounting plate portion 36 that extends perpendicularly from one edge portion of the joint plate portion 35, and a parallel portion from the center of the joint plate portion 35 to the mounting plate portion 36. The projection 37 protrudes toward the side opposite to the mounting plate portion 36. Further, the mounting bracket 16 may be made of resin instead of metal. The joint plate portion 35 and the attachment plate portion 36 are formed by bending one piece of the plate member. A mounting hole 38 is formed in parallel with the joint plate portion 35 in the mounting plate portion 36. The mounting bracket 16 is inserted into the insertion hole 30 while the projection portion 37 is joined to the outside of the lid portion 23 of the pneumatic cylinder 12 by welding or the like. The insertion hole 30 of the lid portion 23 is closed by the engagement.

The piston 13 is composed of a ring-shaped metal piston body 41 and a rubber seal ring 42 held on the outer peripheral side of the piston body 41. Further, the piston 13 may be made of resin instead of metal. In the piston body 41, a through hole 43 having a certain diameter is formed in the center thereof in the axial direction. Shallow recessed holes 44, 45 having a larger diameter than the through hole 43 are formed on both axial sides of the through hole 43. Further, in the piston main body 41, a seal holding groove 46 that is recessed in the radial direction at a constant depth is formed on the entire circumference in the axial center of the outer peripheral portion. Between the recessed holes 44 and 45 in the radial direction and the seal holding groove 46, the passage holes 47 along the axial direction are formed at equal positions at equal intervals from the center of the through hole 43 toward the circumferential direction.

The seal ring 42 is an O-ring having a circular cross section. Sealing ring 42 is by embedding It is held in the seal holding groove 46 and held in the piston body 41. The outer diameter of the portion other than the seal holding groove 46 of the piston main body 41 has a certain diameter, is formed to be smaller than the inner diameter of the cylindrical portion 25, and is slidable in the cylindrical portion 25, and is formed in a ring shape. The inner diameter of the convex portion 27 is larger than the diameter so that the annular convex portion 27 cannot pass through the axial direction. Further, the piston 13 is slidably fitted to the inside of the cap side cylindrical portion 29 in a state where the movement of the piston 13 toward the opening side cylindrical portion 28 side is restricted by the annular convex portion 27. At this time, the piston 13 is such that the seal ring 42 is in close contact with the seal holding groove 46 of the piston body 41, and is in sliding contact with the inner peripheral surface of the cap side cylindrical portion 29 of the pneumatic cylinder 12, and the seal piston body 41 and the cover side are rounded. The gap of the barrel portion 29.

The piston 13 is a gas chamber 50 that is formed between the lid portion 23 and the piston 13 in the pneumatic cylinder 12, and a gas chamber 51 that is opposite to the lid portion 23 of the piston 13. Dry gas G as an operating gas is enclosed in the gas chambers 50 and 51. The gas chambers 50, 51 are connected to each other via a passage hole 47 having a piston 13 that constitutes a press.

The piston rod 14 is made of metal. The piston rod 14 is formed by a main shaft portion 55 having a constant diameter, in addition to chamfering at an end portion inside the pneumatic cylinder 12. The piston rod 14 is formed at an end portion inside the pneumatic cylinder 12 from the main shaft portion 55 side in a predetermined diameter smaller than the minimum diameter portion of the main shaft portion 55, and the end portion opposite to the main shaft portion 55 is inverted. The member fitting shaft portion 57 of the corner; the piston fitting shaft portion 58 having a smaller diameter than the smallest diameter portion of the member fitting shaft portion 57; the mouth portion of the larger diameter than the piston fitting shaft portion 58 (cAulkinG pArt) 59. The piston rod 14 is a through hole 43 that is fitted to the piston 13 at the piston fitting shaft portion 58.

An abutting spacer (restricting means) 63 is fitted to the member fitting shaft portion 57 of the piston rod 14. The abutting spacer 63 is formed by press forming a sheet of a certain thickness of a plate. The abutting spacer 63 has an engaging circular plate portion 65, an intermediate cylindrical portion 66, and an abutting flange portion 67. The engagement circular plate portion 65 has an annular shape in which the insertion hole 64 is formed at the center. The intermediate tubular portion 66 is formed in a tapered cylindrical shape so as to extend toward the outer side from the outer peripheral edge portion of the engaging circular plate portion 65 toward the outer side in the axial direction. The abutting flange portion 67 has an annular shape. The abutting flange portion 67 extends outward in the radial direction from the opposite end of the engaging circular plate portion 65 of the intermediate cylindrical portion 66 in parallel with the engaging circular plate portion 65.

The abutment spacer 63 is in a posture in which the abutting flange portion 67 is disposed on the front side in the insertion direction, and the piston fitting shaft portion 58 and the member fitting shaft portion 57 in front of the mouth of the piston rod 14 are inserted in this order. The insertion hole 64 of the engagement circular plate portion 65 on the deep side of the insertion direction is inserted. In this manner, the member fitting shaft portion 57 is fitted into the insertion hole 64. In this state, when the piston 13 is attached to the piston fitting shaft portion 58 and the mouth portion 59 is formed, the abutting spacer 63 is sandwiched between the end surface of the piston 13 and the member fitting shaft portion 57 of the main shaft portion 55. The disc portion 65 is held and integrated with the piston 13 and the piston rod 14. Further, the abutting flange portion 67 has a smaller outer diameter than the inner diameter of the annular convex portion 27, and is formed so that the annular convex portion 27 can pass through the axial direction.

In order to allow the engagement between the main shaft portion 55 of the piston rod 14 and the engagement disc portion 65 of the piston 13 as described above, the insertion hole 64 of the abutting spacer 63 is larger than the main shaft portion of the piston rod 14. The end surface on the side of the member fitting shaft portion 57 of 55 is formed to have a smaller diameter. Further, the inner diameter of the recess 45 of the piston 13 is The diameter is larger than the member fitting shaft portion 57 and smaller than the outer diameter of the engaging circular plate portion 65. Further, the axial length of the member fitting shaft portion 57 is equal to or less than the length of the recessed hole 45 and the thickness of the engaging circular plate portion 65. In addition, the mouth portion 59 of the piston rod 14 is formed to have the same diameter as the fitting shaft portion 58 in front of the mouth, and protrudes from the piston 13 to have a larger diameter than the through hole 43 by the mouth. The piston 13 is prevented from coming off. In addition, the through hole 47 of the piston main body 41 is formed on the outer peripheral edge portion of the engaging circular plate portion 65 in the radial direction, and may not be closed by the abutting spacer 63.

The rod guide 15 is an annular metal rod guide body 71 that is fitted to the opening portion 22 side of the pneumatic cylinder 12, and a cylindrical shape that is fitted to the inner peripheral side of the rod guide body 71 and held therein. A sliding bushing 72 made of synthetic resin is used. The rod guide main body 71 has a large diameter portion 73 whose outer peripheral side is formed so as to be fitted to the cylindrical portion 25 of the pneumatic cylinder 12 from the one end portion in the axial direction, and is formed at the other end portion in the axial direction. The further away from the large diameter portion 73, the tapered portion 74 that forms the smaller diameter. The tapered portion 74 has a larger outer diameter than the large diameter portion 73. The large diameter portion 73 is fitted by being pressed into the cylindrical portion 25 of the pneumatic cylinder 12. Therefore, the portion of the cylindrical portion 25 that is only press-fitted has a large diameter and is formed to have a larger diameter than the opening-side locking portion 26.

In addition, the rod guide main body 71 has a large diameter hole portion 76 having a constant diameter formed by the one end portion on the large diameter portion 73 side in the axial direction from the intermediate portion, and the other end portion formed in the axial direction. Further, the small diameter hole portion 77 having a smaller diameter than the large diameter hole portion 76 is formed. A sliding bush 72 is fitted to the large diameter hole portion 76. The inner diameter of the slide bushing 72 in a state in which the rod guide main body 71 is fitted is equal to the inner diameter of the small diameter hole portion 77 of the rod guide main body 71. The inner diameter of the sliding bushing 72, It is formed to have a larger diameter than the outer diameter of the main shaft portion 55, and is slidable on the main shaft portion 55 of the piston rod 14. The slide bushing 72 is made of a lubricious synthetic resin such as fluororesin.

Further, the rod guide 15 is disposed in the pneumatic cylinder 12 in a posture in which the tapered portion 74 faces the opening portion 22 side of the pneumatic cylinder 12 . At this time, the tapered portion 74 overlaps the opening-side locking portion 26 in the axial direction, and the large-diameter portion 73 and the opening-side cylindrical portion 28 overlap in the axial direction.

An annular sealing member 81 that slides with the main shaft portion 55 of the piston rod 14 is provided between the piston 13 and the rod guide 15 and on the rod guide 15 side. Further, on the side of the piston 13, a sliding member 82 provided to be slidable in the axial direction in the pneumatic cylinder 12 is provided between the seal member 81 and the piston 13. Further, between the sealing members 81 and the sliding member 82 in the pneumatic cylinder 12, a lubricant holding chamber 83 in which a liquid lubricant L such as lubricating oil is sealed is formed.

The sealing member 81 is composed of a core portion 86 made of a hard material such as metal, and a sealing portion 87 made of a soft sealing material such as rubber covering the core portion 86. The core portion 86 has a circular flat plate-shaped substrate portion 88 having a constant inner diameter and a constant outer diameter, and a cylindrical wall portion 89 extending from the outer peripheral edge portion of the substrate portion 88 to a certain height in the axial direction. The sealing portion 87 covers the entire core portion 86. The sealing portion 87 has a circular flat base portion 92 in which the substrate portion 88 is embedded in parallel, an outer cylindrical portion 93 formed to protrude outward in the axial direction on the outer peripheral edge portion of the base portion 92, and a base portion at the base portion The inner side of the inner peripheral edge portion of 92 has an inner cylindrical portion 94 that protrudes toward the same side as the outer cylindrical portion 93 in the axial direction. The wall portion 89 of the core portion 86 is in the outer cylindrical portion 93 in such a manner as to coincide with the center of the outer cylindrical portion 93. Be buried. The outer peripheral portion on the protruding distal end side of the outer tubular portion 93 has an annular notch. The axial length of the outer tubular portion 93 is longer than the axial length of the inner cylindrical portion 94. Further, when the sealing portion 87 is resin-molded by a mold, the core portion 86 is placed in the mold in advance and integrated with the sealing portion 87.

When the sealing member 81 is in a natural state, the inner diameter of the inner cylindrical portion 94 is smaller than the main shaft portion 55 of the piston rod 14, and the outer diameter of the outer cylindrical portion 93 is larger than the inner diameter of the opening-side cylindrical portion 28 of the pneumatic cylinder 12. The path is larger. Further, the sealing member 81 abuts the base portion 92 of the sealing portion 87 against the rod guide 15, and fits into the outer peripheral surface of the outer cylindrical portion 93 in the opening-side cylindrical portion 28 of the pneumatic cylinder 12, and the main shaft of the piston rod 14 The portion 55 is slidably inserted into the inner peripheral side of the inner cylindrical portion 94. Thereby, the sealing member 81 closes the gap with the piston rod 14 while closing the gap between the pneumatic cylinders 12. Further, the sealing member 81 is provided with fitting conditions for the pneumatic cylinder 12, and this condition is such that the piston rod 14 does not move relative to the pneumatic cylinder 12 even if it slides.

The sliding member 82 is composed of a high-strength portion (non-sliding portion) 98 made of a hard material such as metal, and a sliding portion 99 made of a soft sealing material such as rubber partially covering the high-strength portion 98. The high-strength portion 98 has a circular flat plate shape having a constant inner diameter and a constant outer diameter. The sliding portion 99 has a substantially cylindrical main portion 100, a connecting portion 101 extending inward in the radial direction from the inner peripheral portion of the main portion 100 in the axial direction, and an axial portion extending from the inner peripheral portion of the connecting portion 101. A cylindrical lip (discharge mechanism) 102 that extends toward the same side as the main portion 100. Further, the high-strength portion 98 is integrated with the sliding portion 99 so as to be placed in the mold beforehand in the resin molding of the mold of the sliding portion 99.

The main portion 100 of the sliding portion 99 has a high-strength portion 98 embedded in an end portion on the opposite side of the connecting portion 101 in the axial direction. The high-strength portion 98 is exposed not to be covered by the sliding portion 99 on the opposite side of the connecting portion 101 in the axial direction. The main portion 100 is a flat surface on the opposite side to the connecting portion 101 including the high-strength portion 98 in a direction orthogonal to the axis. On the other hand, the continuous surface of the main portion 100, the connecting portion 101, and the lip portion 102 on the side opposite to the surface of the sliding portion 99 is a tapered surface which is formed on the side of the high-strength portion 98 so as to be inclined toward the axial direction. . Further, the main portion 100 has a constant outer diameter and a constant inner diameter. The lip portion 102 has a tapered cylindrical shape that is formed to have a smaller diameter from the connecting portion 101 as it is in the natural state. When the sliding member 82 is in the natural state, the minimum inner diameter of the lip portion 102 is smaller than the main shaft portion 55 of the piston rod 14, and the outer diameter of the main portion 100 is larger than the inner diameter of the opening-side cylindrical portion 28 of the pneumatic cylinder 12. .

The high-strength portion 98 has an outer diameter smaller than the outer diameter of the main portion 100, and the inner diameter is larger than the inner diameter of the main portion 100. The high-strength portion 98 is embedded in the main portion 100 so as to coincide with the center of the sliding portion 99. Thereby, the high-strength portion 98 is disposed only in the intermediate range of the main portion 100 in the radial direction. Further, the outer diameter of the high-strength portion 98 is equivalent to the outer diameter of the abutting flange portion 67 of the abutting spacer 63.

In the posture in which the connecting portion 101 and the sealing member 81 are opposed to each other, the sliding portion 82 is fitted to the outer peripheral surface of the main portion 100 in the opening side cylindrical portion 28 of the pneumatic cylinder 12, and the main shaft portion 55 of the piston rod 14 is slidable. The ground is inserted into the inner peripheral side of the lip portion 102 of the sliding portion 99. Thereby, the sliding member 82 closes the gap with the pneumatic cylinder 12, and closes the gap with the piston rod 14. In addition, sliding The member 82 is provided with fitting conditions for the pneumatic cylinder 12 that do not move even when the pneumatic cylinder 12 is slid even if the piston rod 14 slides. Further, the sliding member 82 is provided with a fitting condition for the pneumatic cylinder 12, and the condition is such that the change in the amount of the lubricating material L in the lubricant holding chamber 83 can be performed at any time and the pneumatic cylinder 12 can be moved during assembly as will be described later. . That is, the sliding member 82 is configured such that the sliding portion 99 formed of a soft material can relatively move against the inner circumference of the pneumatic cylinder 12 and the piston rod 14 in sliding contact. On the other hand, the high-strength portion 98 formed of a material harder than the sliding portion 99 is a non-sliding portion that cannot be in sliding contact with any of the inner circumference of the pneumatic cylinder 12 and the piston rod 14.

Here, in the middle of the assembly process of the gas spring, in the state in which the annular convex portion 27 is not formed in the pneumatic cylinder 12, the contact pad 63 provided on the piston rod 14 is abuttable against the sliding member 82. In a state where the abutting spacer 63 abuts against the sliding member 82, the relative movement in the axial direction of the abutting pad 63 to be passed over the sliding member 82 is restricted. When the abutment pad 63 abuts against the sliding member 82 as described above, the abutting flange portion 67 of the abutting pad 63 abuts against the high-strength portion 98 of the sliding member 82. In addition, after the assembly of the gas spring, the annular convex portion 27 formed in the pneumatic cylinder 12 restricts the movement of the piston 13 and is formed at a position (described later) at which the contact pad 63 can be prevented from coming into contact with the sliding member 82.

The lip portion 102 provided on the inner circumference of the sliding member 82 has a front end that extends toward the piston 13 side. The lip portion 102 is deformed toward the main portion 100 side in the radial direction when the pressure in the lubricant holding chamber 83 is higher than the pressure of the air chamber 51 between the piston 13 and the sliding member 82 in the pneumatic cylinder 12. A gap is formed between the 14 and the lubricant holding chamber 83 and the air chamber in the pneumatic cylinder 12 51 connected. Thereby, when assembled as will be described later, the lip portion 102 is deformed so that the lubricant holding chamber 83 communicates with the air chamber 51 in the pneumatic cylinder 12, and a lubricant holding chamber which can remain between the sealing member 81 and the sliding member 82 is formed. The residual air in 83 is discharged to the air chamber 51. Further, the lip portion 102 functions as a check valve to restrict the movement of the gas G or the like from the gas chamber 51 to the lubricant holding chamber 83.

The assembly of the gas spring described above will be described.

First, as shown in FIG. 2A, the pneumatic cylinder 12 in a state before the opening-side locking portion 26 and the annular convex portion 27 shown in FIG. 1 are prepared. The pneumatic cylinder 12 is held in a vertical posture in which the lid portion 23 is located on the lower side. Then, the piston rod 14 in a state in which the piston 13 and the abutting washer 63 are attached in advance is inserted into the pneumatic cylinder 12 from the upper opening 22 so that the piston 13 faces downward. At this time, the piston 13 is inserted into the predetermined piston reference position set in advance with respect to the pneumatic cylinder 12. Further, at this time, in the main shaft portion 55 of the piston rod 14, the sliding member 82, the sealing member 81, and the rod guide 15 are arranged in advance from the piston 13 side at a position away from the piston 13. In this state, a mounting bracket (not shown) is fixed to the opposite end of the piston 13 of the main shaft portion 55 of the piston rod 14.

Next, as shown in FIG. 2B, the extending side of the lip portion 102 is directed toward the piston 13 in advance, and the sliding member 82 in a state in which the piston rod 14 is inserted into the inner side of the lip portion 102 is inserted from the opening portion 22 into the pneumatic cylinder 12. At this time, the piston 13 is maintained in the above-described state of the piston reference position, and the slide member 82 is inserted into the predetermined sliding member reference position set in advance with respect to the pneumatic cylinder 12. In this state, the sliding member 82 is The lip portion 102 is in close contact with the piston rod 14, and the main portion 100 is in close contact with the inner circumferential surface of the pneumatic cylinder 12.

Next, as shown in FIG. 2C, a predetermined amount of the lubricant L set in advance on the upper side of the sliding member 82 in the pneumatic cylinder 12 is injected from the opening 22. Then, the lubricant L is stored in the pneumatic cylinder 12 by gravity in the lower sliding member 82. At this time, as described above, since the sliding member 82 is in close contact with the piston rod 14 and the pneumatic cylinder 12, it is maintained at the sliding member reference position, and the leakage from the sliding member 82 of the lubricant L to the lower side is restricted.

Then, as shown in FIG. 3A, the base member 92 is provided in advance with the sealing member 81 in the posture on the opposite side of the piston 13 and the rod guide 15 in the posture in which the sliding bush 72 is placed on the piston 13 side in advance. The opening 22 is pressed into the pneumatic cylinder 12. At this time, the piston 13 is maintained in the above-described state of the piston reference position, and the sliding member 82 is maintained in the above-described state of the sliding member reference position, and the sealing member 81 is pressed into position in the pneumatic cylinder 12 in advance. The predetermined sealing member is disposed at a position, and the rod guide 15 is pressed into position with respect to the pneumatic cylinder 12 at a predetermined rod guide arrangement position set in advance. Further, when the sealing member 81 is positioned at the position where the sealing member is disposed, it is positioned above the liquid surface of the lubricant L, and a predetermined gap remains between the liquid surface and the liquid surface.

In this state, the opening portion 22 side of the pneumatic cylinder 12 is plastically deformed by the rolling process, and the opening-side locking portion 26 is formed in a predetermined range from the end portion to the axial direction set in advance. Thereby, the end surface of the large diameter portion 73 of the rod guide 15 on the tapered portion 74 side is locked to the opening side locking portion 26, and the rod guide 15 is prevented from coming off the pneumatic cylinder 12.

Next, as shown in FIG. 3B, the pneumatic cylinder 12 is vertically inverted together with the piston rod 14 or the like assembled to the pneumatic cylinder 12. Then, the lubricant L is stored in the pneumatic member 12 on the sealing member 81 by gravity. At this time, the sliding member 82 which is the upper side of the sealing member 81 is formed between the sealing member 81 and the lubricant holding chamber 83 which holds the lubricant L, and between the liquid level of the lubricant L and the lubricant holding chamber 83. A predetermined gap remaining in the residual air G' is formed.

Next, the piston rod 14 is pulled out from the pneumatic cylinder 12 only by a predetermined amount of pull-out set in advance. Then, as shown in FIG. 3B and FIG. 4, the abutting spacer 63 integrally moved with the piston rod 14 abuts against the high-strength portion 98 of the sliding member 82 at the abutting flange portion 67, as shown in FIG. 3B and FIG. In a state in which the movement of the piston rod 14 of the slide member 82 is restricted, the slide member 82 is integrally moved toward the seal member 81 side. Then, the volume in the lubricant holding chamber 83 between the sliding member 82 and the sealing member 81 becomes smaller, the pressure rises, and the residual air G' located in the upper portion in the lubricant holding chamber 83 deforms the lip 102 of the sliding member 82. The gap from the lip portion 102 and the piston rod 14 is discharged over the sliding member 82 toward the piston 13 side in the pneumatic cylinder 12. In other words, the lip portion 102 of the sliding member 82 discharges the residual air G' remaining in the lubricant holding chamber 83 at the time of assembly. Then, when the piston rod 14 is pulled out from the pneumatic cylinder 12 by a predetermined amount of drawing, the residual air G' remaining in the lubricant holding chamber 83 is completely discharged as shown in Fig. 3C.

Here, the amount of the residual air G' is a predetermined amount of space between the sealing member 81 at the position where the sealing member is disposed in the pneumatic cylinder 12 and the sliding member 82 at the position where the sliding member is disposed. Cast The value obtained by the amount. The piston rod 14 is a predetermined amount of pull-out which can be pulled out to discharge the residual air G'. Further, at this time, since only a small amount of the lubricant L leaks from the sliding member 82 to the side of the piston 13 does not affect, the piston rod 14 can be pulled out only in an amount that can compensate the error, and the residual air G can be removed. 'It is completely discharged from the lubricant holding chamber 83.

Next, as shown in FIG. 3C, only the piston rod 14 is pushed into the pneumatic cylinder 12 by a predetermined amount of pushing. Then, the predetermined position set by the predetermined position of the pneumatic cylinder 12 is plastically deformed by the rolling process to form the annular convex portion 27. Further, the above-described predetermined amount of pushing of the piston rod 14 does not interfere with the formation of the annular projection 27, and after the annular projection 27 is formed, the piston 13 is positioned at the annular projection 27. The sliding member 82 is on the opposite side.

Next, the drying gas as the operating gas is introduced into the air chambers 50 and 51 through the insertion hole 30, and as shown in FIG. 1, the mounting bracket 16 is joined to the lid portion 23 of the pneumatic cylinder 12 to close the insertion hole 30.

As above, the assembly of the gas spring is completed. In the gas spring assembled as described above, the rod guide 15, the sealing member 81, the lubricant holding chamber 83, and the sliding member 82 are disposed in the opening-side cylindrical portion 28 which is located on the opening side from the annular convex portion 27 of the pneumatic cylinder 12. The piston 13 is disposed in the cap side cylindrical portion 29 on the side of the lid portion 23 than the annular convex portion 27. By abutting against the annular convex portion 27, the movement of the piston 13 beyond the side toward the sliding member 82 is restricted, and the movement of the abutting spacer 63 integrally formed with the piston 13 toward the sliding member 82 side is also restricted. As shown in Fig. 1, the piston 13 is most moved toward the sliding member 82 side, and when the annular convex portion 27 is in contact with each other, the abutting spacer 63 becomes slippery. The moving member 82 is not abuttable, and the sliding member 82 often has an axial gap. That is, the annular convex portion 27 prevents the contact pad 63 from coming into contact with the sliding member 82 after the assembly of the gas spring.

The gas spring described above is a member in which the mounting bracket which is omitted from the side opposite to the pneumatic cylinder 12 of the piston rod 14 and the mounting bracket 16 fixed to the pneumatic cylinder 12 are coupled to each other in relative movement. Further, when the two parts approach each other, the piston rod 14 enters the pneumatic cylinder 12, whereby the piston 13 is moved toward the side of the lid portion 23 of the pneumatic cylinder 12. Then, the gas G in the gas chamber 50 on the side of the lid portion 23 moves toward the inside of the gas chamber 51 on the opposite side of the lid portion 23 via the passage hole 47 of the piston 13, and at this time, the passage hole 47 is pressed to generate a degrading force. On the contrary, when the two parts are separated from each other, the piston rod 14 is pulled out from the pneumatic cylinder 12, whereby the piston 13 is moved toward the side opposite to the lid portion 23 of the pneumatic cylinder 12. Then, the gas G in the gas chamber 51 on the side opposite to the lid portion 23 moves toward the inside of the gas chamber 50 on the side of the lid portion 23 via the passage hole 47 of the piston 13, and at this time, the passage hole 47 is pressed to cause a degrading force. In this way, the relative movement of the two parts functions as a buffer.

Further, since the lubricant holding chamber 83 is filled with the lubricant L, the sliding member 82 and the sealing member 81 of the lubricant holding chamber 83 are formed, regardless of the posture of the gas spring and the movement of the piston rod 14, often with lubrication. Agent L is in contact. Further, as the lubricant L in the lubricant holding chamber 83 decreases as time passes, as the sliding member 82 moves, the volume of the lubricant holding chamber 83 is reduced.

According to the above, in the gas spring described above, even when the mounting bracket 16 is located on the upper side, the piston rod 14 is placed on the lower side in the inverted state, and the mounting bracket 16 positions. On the lower side, any of the state in which the piston rod 14 is located on the upper side in the upright state and the side surface may be attached.

In the gas spring described in Japanese Laid-Open Patent Publication No. 2002-372087, the lubricant is immersed in the impregnating member, but the piston rod that is in contact with the impregnating member slides on the sealing member to supply the lubricant to the sealing member. According to this configuration, when the movement of the piston rod is not performed, the sealing member is dried to lower the sealing property, and there is a possibility that the operating gas in the pneumatic cylinder leaks to the outside.

On the other hand, according to the first embodiment described above, the seal member 81 and the slide member 82 are provided between the piston 13 and the rod guide 15, and the lubricant retaining chamber 83 is provided between the slide member and the slide member. 82 is provided with a lip portion 102 that discharges residual air G' remaining in the lubricant holding chamber 83 at the time of assembly. Therefore, the residual air G' is discharged to fill the lubricant L in the lubricant holding chamber 83. Therefore, even if the movement of the piston rod 14 is not provided, even if it is disposed in any orientation, the lubricant L can be often brought into contact with the sealing member 81 and the sliding member 82, and the state of being wetted can be maintained. Thereby, leakage of the operating gas due to drying of the sealing member 81 and the sliding member 82 can be suppressed. Therefore, high airtightness can be maintained.

In addition, since the lubricant holding chamber 83 filled with the lubricant L is formed between the sealing member 81 and the sliding member 82 that is slidable in the axial direction in the pneumatic cylinder 12, the capacity is variable. Therefore, the degree of freedom in setting the amount of the lubricant L can be increased, and the set width of the spring coefficient can be widened.

Further, the sliding member 82 disposed on the side of the piston 13 is provided with the lip portion 102 as the residual air G' remaining in the lubricant holding chamber 83 at the time of assembly. The mechanism discharges the residual air G' so that the lubricant holding chamber 83 communicates with the air chamber 51 in the pneumatic cylinder 12 by the lip portion 102. Therefore, even when the residual air G' is discharged during assembly, for example, when the lubricant L leaks from the lubricant holding chamber 83, the leaking end is the gas chamber 51 in the pneumatic cylinder 12 in which the operating gas is enclosed, and There will be no leakage outside the gas spring. Therefore, leakage to the outside of the gas spring of the lubricant L can be suppressed.

Further, since the lip portion 102 that extends toward the side of the piston 13 on the inner circumference of the sliding member 82 serves as a mechanism for discharging the residual air G' remaining in the lubricant holding chamber 83 at the time of assembly, the residual air can be discharged in a simple configuration. G'. Therefore, the cost can be reduced.

In addition, the piston rod 14 is abutted against the high-strength portion 98A formed of the hard material of the sliding member 82 by the abutting spacer 63 that abuts against the relative movement of the sliding member 82 in the axial direction. . Therefore, damage to the sliding portion 99 formed of a soft material that is slidably engaged with the inner circumference of the pneumatic cylinder 12 of the sliding member 82 and the piston rod 14 can be suppressed.

Further, since the annular convex portion 27 provided in the pneumatic cylinder 12 prevents the abutting spacer 63 from coming into contact with the sliding member 82 after the assembly of the gas spring, the gasket abuts against the gasket when the gas spring is actuated. The pressing of the sliding member 82 by the 63 does not cause the lubricant L to leak from the lubricant holding chamber 83. Therefore, the lubricant L can be well maintained in the lubricant retaining chamber 83.

Further, instead of the sliding member 82 of the first embodiment described above, a sliding member 82A to which a small change is applied as shown in FIG. 5 may be used.

The sliding member 82A has a main portion 100A having a substantially cylindrical shape of a sliding portion 99A made of a soft material, and an outer side of the main portion 100A from the axial side. A connecting portion 101A extending outward in the radial direction of the circumferential portion, and a cylindrical lip portion (discharging mechanism) 102A extending outward from the outer peripheral edge portion of the connecting portion 101A in the axial direction toward the main portion 100A. That is, the sliding member 82A has the lip portion 102A at the outer peripheral portion instead of the inner peripheral portion. Accordingly, the high-strength portion (non-sliding portion) 98A composed of a constant inner diameter smaller than the high-strength portion 98 and a circular flat plate-shaped hard material having a constant outer diameter, and the shaft of the main portion 100A. The intermediate portion in the radial direction opposite to the connecting portion 101A is buried so as to be exposed to the opposite side of the connecting portion 101A.

The main portion 100A of the sliding portion 99A is formed on a surface opposite to the connecting portion 101A including the high-strength portion 98A in a plane orthogonal to the axis, and the main portion 100A, the connecting portion 101A, and the lip on the opposite side to the surface of the sliding portion 99A. The continuous surface of the portion 102A is formed such that the outer side of the outer portion is inclined toward the side of the piston 13 in the axial direction. The main portion 100A has a certain diameter formed by the outer diameter and the inner diameter. The lip portion 102A has a tapered cylindrical shape that is formed to have a larger diameter on the opposite side of the axial direction connecting portion 101A in the natural state.

Further, the outer diameter of the high-strength portion 98A is reduced, and the abutting gasket 63A which is changed a small amount is used. The contact pad 63A has an engagement circular plate portion 65, an intermediate cylindrical portion 66A, and an abutting flange portion 67A. The engaging circular plate portion 65 has the same insertion hole 64 as described above. The intermediate tubular portion 66A extends in a cylindrical shape having a constant diameter from the outer peripheral edge portion of the engaging disc portion 65 different from the above. The abutting flange portion 67A has an annular shape. The abutting flange portion 67A extends outward in the radial direction parallel to the engaging circular plate portion 65 from the opposite side of the engaging circular plate portion 65 of the intermediate cylindrical portion 66A. The outer diameter of the abutting flange portion 67A of the abutting spacer 63A is outside the high-strength portion 98A. The diameter is equal.

The sliding member 82A is in a posture in which the extending side of the lip portion 102A of the sliding portion 99A faces the piston 13, and the cylindrical portion 28 on the opening side of the pneumatic cylinder 12 is fitted to the outer peripheral surface of the lip portion 102A, and is the main portion of the sliding portion 99A. A main shaft portion 55 of the piston rod 14 is inserted into the inner peripheral side of the portion 100A. When the piston rod 14 slides, the sliding member 82A sets the fitting condition for the pneumatic cylinder 12 so as not to move with respect to the pneumatic cylinder 12.

The lip portion 102A provided on the outer circumference of the sliding member 82A is a gas chamber 51 between the piston 13 and the sliding member 82A in the cylinder 2 in the pressure holding chamber 83A on the opposite side to the piston 13 of the sliding member 82A. When the pressure is higher, the main portion 100A side in the radial direction is deformed, and a gap is formed between the cylinder and the pneumatic cylinder 12, and the lubricant holding chamber 83A communicates with the air chamber 51 in the pneumatic cylinder 12. Thereby, at the time of assembly of the gas spring, the lip portion 102A is deformed, and the lubricant holding chamber 83 communicates with the gas chamber 51 in the pneumatic cylinder 12 in the same manner as described above, and the residual air G' remaining in the lubricant holding chamber 83A is retained. It is discharged to the gas chamber 51.

"Second embodiment"

Next, a second embodiment will be described mainly on the basis of differences from the first embodiment with reference to Figs. 6 to 8B. In addition, the parts common to the first embodiment are denoted by the same reference numerals and the same symbols.

In the second embodiment, the pneumatic cylinder 12B that has been changed slightly is used with respect to the first embodiment. The pneumatic cylinder 12B has an opening portion 22 formed at one end in the axial direction, and a cylindrical portion 21B that closes the other end with the lid portion 23 is: The cylindrical portion 25B having a constant diameter forming the annular convex portion 27 of the first embodiment and the opening-side locking portion 26 at the end portion on the side of the opening 22 are formed. Further, in the second embodiment, the contact pad 63 of the first embodiment is not provided in the piston rod 14.

A rod guide 110 different from that of the first embodiment is provided on the opening portion 22 side of one end in the pneumatic cylinder 12B. The rod guide 110 is an annular metal member that is fitted to the pneumatic cylinder 12B.

The rod guide 110 has a large diameter portion 111 formed at one end portion in the axial direction on the outer circumferential side, an intermediate diameter portion 112 formed in the intermediate portion in the axial direction and having a smaller diameter than the large diameter portion 111, and another axial portion formed in the axial direction. The one end portion has a smaller diameter portion 113 than the intermediate diameter portion 112.

In the large-diameter portion 111, a seal holding groove 115 recessed at a constant depth is formed in the inner circumference in the radial direction of the entire center in the axial direction of the outer peripheral portion. The large diameter portion 111 has a certain diameter which is an outer diameter of a portion other than the seal holding groove 115. Since the large diameter portion 111 is fitted by being pressed into the cylindrical portion 25B of the pneumatic cylinder 12B, only the portion of the pressing amount is slightly larger than the cylindrical portion 25B and formed larger than the opening side locking portion 26. Bigger path. Further, since the intermediate diameter portion 112 is disposed inside the opening-side locking portion 26, a predetermined diameter smaller than the opening-side locking portion 26 is formed. The small diameter portion 113 has a certain diameter and protrudes toward the pneumatic cylinder 12B.

The inner peripheral side of the rod guide 110 is a through hole 116 that constitutes a certain diameter. The through hole 116 is configured to be slightly larger than the outer diameter of the main shaft portion 55 so as to be slidable on the main shaft portion 55 of the piston rod 14.

A rubber sealing ring is held on the outer peripheral side of the rod guide 110 (sealing hand) Section) 117. The seal ring 117 is an O-ring having a circular cross section. The seal ring 117 is held by the rod guide 110 by being fitted into the seal holding groove 115. The seal ring 117 is in close contact with the seal holding groove 115 of the rod guide 110, and is in close contact with the inner peripheral surface of the cylindrical portion 25B of the pneumatic cylinder 12B to seal the gap between the rod guide 110 and the cylindrical portion 25B.

Between the piston 13 and the rod guide 110, an annular seal member 119 that slides on the rod guide 110 side and the main shaft portion 55 of the piston rod 14 is provided. Further, between the rod guide 110 and the sealing member 119, a gasket-type gasket (discharge mechanism, closing mechanism, annular plate) 120 for forming an annular plate is provided. Further, a sliding member 121 provided between the seal member 119 and the piston 13 and slidable in the axial direction is provided on the piston 13 side. Further, a lubricant holding chamber 83B in which the lubricant L is sealed is formed between the gasket-type gasket 120, the sealing member 119, and the sliding member 121. Further, a gas chamber 51B is formed between the piston 13 and the sliding member 121.

The sealing member 119 is made of a soft sealing material such as rubber. The discharge holes 125 penetrating the axial direction of the sealing member 119 form a circumferential direction at equal intervals. The plurality of discharge holes 125 have a large diameter on one side in the axial direction and a small diameter on the other side in the axial direction. When the sealing member 119 is in the natural state, the inner circumferential surface becomes smaller toward the axial direction (the large diameter side of the discharge hole 125), and the minimum diameter thereof is smaller than the main shaft portion 55 of the piston rod 14. Further, the outer diameter is slightly larger than the inner diameter of the cylindrical portion 25 of the pneumatic cylinder 12B. In the sealing member 119, the small diameter side of the discharge hole 125 is directed toward the rod guide 110 side, and the outer peripheral portion is fitted into the cylindrical portion 25B of the pneumatic cylinder 12B, and the main shaft portion 55 of the piston rod 14 is slidably inserted. Zhou. Thereby, the sealing member 119 is closed The gap between the plug and the pneumatic cylinder 12B is blocked, and the gap with the piston rod 14 is closed. Further, the sealing member 119 is provided with a fitting condition for the pneumatic cylinder 12, and the condition is that the pneumatic cylinder 12 does not move even if the piston rod 14 slides.

The gasket type gasket 120 is made of rubber. The gasket-type gasket 120 has an inner diameter that is slightly smaller than the main shaft portion 55 of the piston rod 14 and an outer diameter that is smaller than the inner diameter of the pneumatic cylinder 12B in a natural state. The gasket-type gasket 120 is disposed on the small-diameter side of the discharge hole 125 with respect to the sealing member 119, and closes the small-diameter side of the plurality of discharge holes 125 in a state of abutting against the sealing member 119.

The sliding member 121 is composed of an annular metal member sliding member body 128, a rubber sealing ring 129 held on the outer peripheral side of the sliding member body 128, and a rubber member held on the inner peripheral side of the sliding member body 128. The seal ring 130 is constructed. The sliding member 121 is a free piston that moves in accordance with a change in the amount of liquid in the lubricant holding chamber 83B.

In the outer peripheral portion of the sliding member body 128, a seal holding groove 132 recessed at a certain depth in the radial direction is formed over the entire circumference in the axial center. The outer peripheral portion of the sliding member main body 128 has a predetermined diameter and a smaller diameter than the cylindrical portion 25B, and is formed in the cylindrical portion 25B of the pneumatic cylinder 12B. Further, in the inner peripheral portion of the sliding member main body 128, a seal holding groove 133 which is recessed outward in the radial direction at a predetermined depth is formed over the entire circumference in the axial center. The inner peripheral portion of the sliding member main body 128 has a certain inner diameter of a portion other than the seal holding groove 133, and is formed to have a larger diameter than the main shaft portion 55 so as to be inserted into the main shaft portion 55 of the piston rod 14. .

The seal ring 129 is an O-ring having a circular cross section. The seal ring 129 is held in the seal holding groove 132 and held by the slide member body 128. The seal ring 129 is in close contact with the seal holding groove 132 of the slide member body 128, and is in close contact with the inner peripheral surface of the cylindrical portion 25B of the pneumatic cylinder 12B, and seals the gap between the slide member body 128 and the cylindrical portion 25B.

The seal ring 130 is an O-ring having a circular cross section. The seal ring 130 is held by the slide member body 128 by being fitted into the seal holding groove 133. The seal ring 130 is in close contact with the seal holding groove 133 of the slide member body 128, and is in close contact with the main shaft portion 55 of the piston rod 14, and the gap between the slide member body 128 and the main shaft portion 55 is avoided.

Here, the sealing member 119 communicates between the lubricant holding chamber 83B and the rod guide 110 via the discharge path (discharge mechanism) 135 in the discharge hole 125 in a state where the gasket type gasket 120 does not abut. Thereby, at the time of assembly to be described later, the opening portion 22 before the rod guide 110 is disposed in the lubricant holding chamber 83B and the pneumatic cylinder 12B can be communicated via the discharge path 135, whereby the sealing member 119 and the sliding member can be formed. The residual air in the lubricant holding chamber 83B between the members 121 is discharged to the outside of the lubricant holding chamber 83B. That is, the discharge path 135 which is formed in the sealing member 119 to discharge the residual air, and the gasket-type gasket 120 which is interposed between the sealing member 119 and the rod guide 110 to close the discharge path 135, are discharged in the lubricant at the time of assembly. The residual air in the chamber 83B is held, and the lubricant holding chamber 83B is sealed after being discharged.

Next, an assembly process of assembling the gas spring of the second embodiment described above will be described.

First, as shown in FIG. 7, the opening side shown in FIG. 6 is not prepared. The pneumatic cylinder 12B in the state of the locking portion 26. The pneumatic cylinder 12B is held in a vertical posture in which the lid portion 23 is positioned on the lower side. Then, the piston rod 14 in a state in which the piston 13 is attached in advance is inserted into the pneumatic cylinder 12B from the upper opening portion 22 with the piston 13 facing downward. At this time, the piston 13 is inserted into position in the previously set range with respect to the pneumatic cylinder 12B. Further, at this time, in the main shaft portion 55 of the piston rod 14, at the position away from the piston 13, the sliding member 121, the sealing member 119, the gasket-type spacer 120, and the rod guide 110 are arranged in advance from the piston 13 side.

Next, the sliding member 121 is inserted into the pneumatic cylinder 12B from the opening portion 22. At this time, the sliding member 121 is inserted into the predetermined sliding member reference position set in advance with respect to the pneumatic cylinder 12B. In this state, the sliding member 121 is in close contact with the inner circumferential surface of the pneumatic cylinder 12B by the seal ring 129, and is in close contact with the piston rod 14 by the seal ring 130.

Next, a predetermined amount of the lubricant L set in advance is injected from the opening 22 on the upper side of the sliding member 121 in the pneumatic cylinder 12B. Then, the lubricant L is stored in the pneumatic cylinder 12 by gravity on the sliding member 121 which becomes the lower side. At this time, as described above, since the sliding member 121 is in close contact with the piston rod 14 and the pneumatic cylinder 12, the lubricant L does not leak to the lower side than the sliding member 121.

Then, as shown in FIG. 8A, the sealing member 119 in which the large diameter side of the discharge hole 125 is the lower side is inserted into the pneumatic cylinder 12B from the opening 22 in advance. In this case, while the sliding member 121 is maintained in the above-described state of the sliding member reference position, the sealing member 119 is inserted into the predetermined sealing member arrangement position set in advance with respect to the pneumatic cylinder 12B. So far. Then, after the air cylinder 12B is fitted into the air cylinder 12B, the sealing member 119 moves the residual air between the liquid surface of the lubricant L and the liquid surface of the lubricant L from the large diameter side toward the small diameter side, and discharges it on the opening portion 22 side. Further, when the sealing member 119 is positioned at the sealing member disposing position, the residual air positioned between the liquid surface and the liquid surface is completely discharged, and the upper surface is positioned at a lower side than the liquid surface of the lubricant L by a predetermined amount.

Next, as shown in FIG. 8B, the gasket-type gasket 120 is inserted into the pneumatic cylinder 12B from the opening 22. At this time, the sliding member 121 is maintained at the above-described sliding member reference position, and the sealing member 119 is maintained in the above-described state in which the sealing member is disposed, and the gasket-type spacer 120 is inserted into a position in contact with the sealing member 119. Then, the gasket type gasket 120 closes all the discharge passages 135 of the sealing member 119. Further, at this time, the lubricant L overflowing above the sealing member 119 runs to the gap between the gasket type liner 120 and the pneumatic cylinder 12B.

Then, the rod guide 110 in a state in which the seal ring 117 is attached in advance is pressed into the pneumatic cylinder 12B from the opening 22 with the large diameter portion 111 as the lower side. At this time, the rod guide 110 is pressed into position with respect to the pneumatic cylinder 12B at a predetermined predetermined rod guide arrangement position. Then, the rod guide 110 is held together with the sealing member 119 with the gasket type liner 120 interposed therebetween.

Then, the opening portion 22 side of the pneumatic cylinder 12B is plastically deformed by the rolling process, and as shown in FIG. 6, the opening-side locking portion 26 is formed in a predetermined range from the end portion to the axial direction set in advance. Thereby, the end surface of the large diameter portion 111 of the rod guide 110 on the intermediate diameter portion 112 side is locked to the opening side locking portion 26, and the rod guide 110 is prevented from coming off the pneumatic cylinder 12B.

As in the above manner, the assembly work of the gas spring is completed.

According to the second embodiment described above, the residual air remaining in the lubricant holding chamber 83B at the time of assembly is discharged via the discharge path 135. Thereafter, the discharge path 135 is closed by the gasket-type gasket 120, and leakage of the lubricant from the lubricant holding chamber 83B is restricted. Therefore, it is possible to more reliably perform the leakage of the residual air and the leakage of the lubricant after the discharge.

In the sealing member 119 on the side of the opening 22 of the pneumatic cylinder 12B in the lubricant holding chamber 83B, the discharge path 135 is formed, and the residual air remaining in the lubricant holding chamber 83B at the time of assembly is discharged through the discharge path 135. Thereafter, the discharge path 135 is closed by the gasket type gasket 120, and leakage of the lubricant L from the lubricant holding chamber 83B is restricted. Therefore, it is not necessary to reverse up and down in the assembly process. Therefore, the assembly work is further made easier.

Further, the occlusion mechanism 135, the occlusion mechanism that restricts the leakage of the lubricant from the lubricant holding chamber 83B, is constituted by an annular plate, and is a gasket-type gasket 120 that is held between the sealing member 119 and the rod guide 110. Therefore, it is possible to more reliably limit the leakage of the lubricant from the lubricant holding chamber 83B.

Further, since the seal ring 117 is provided between the rod guide 110 and the pneumatic cylinder 12B, leakage of the lubricant L to the gap formed by the gasket-type gasket 120 and the pneumatic cylinder 12B during assembly can be restricted to the outside. .

"Third embodiment"

The third embodiment will be described mainly on the basis of the differences from the first and second embodiments with reference to Figs. 9 to 11 . In addition, the parts common to the first embodiment and the second embodiment are denoted by the same reference numerals and the same reference numerals.

In the third embodiment, the pneumatic cylinder 12B similar to the second embodiment is provided with a rod guide 15 similar to that of the first embodiment, and a sliding member 121 similar to that of the second embodiment. Between the rod guide 15 and the sliding member 121, the sealing member 81C which is changed slightly with respect to the first embodiment is abutted against the rod guide 15. Further, between the sealing member 81C and the sliding member 121, a lubricant holding chamber 83C in which the lubricant L is sealed is formed.

The sealing member 81C is a sealing portion 87C having a small change from the first embodiment. In the seal portion 87C, the outer tubular portion 93 and the inner tubular portion 94 which are similar to the first embodiment are formed to protrude in the axial direction from the outer peripheral edge portion and the inner peripheral edge portion of the circular flat base portion 92C. On the side opposite to the direction in which the base portion 92C of the inner cylindrical portion 94 protrudes, a valve portion (discharge mechanism, closing mechanism) 140 that extends outward in the radial direction is formed. As shown in FIG. 10, the valve portion 140 is inclined in the natural state, and is separated from the base portion 92C in the axial direction from the outer side in the radial direction, and is integrally formed at the time of molding the sealing portion 87C.

The sealing member 81C is a core portion 86C that has a small change with the base portion 92C with respect to the first embodiment. In other words, in the sealing member 81C, the wall portion 89 is formed in a circular flat plate shape of the core portion 86C, and the substrate portion 88C extending from the outer peripheral edge portion toward the axial side and the base portion 92C positioned at the sealing portion 87C are oriented toward the shaft. The plurality of discharge holes 142 penetrating the same are formed at equal intervals in the circumferential direction. The discharge hole 142 is formed on the outer side in the radial direction from the base end position of the valve portion 140. Thereby, the valve portion 140 opens the discharge hole 142 in a natural state, and closes the discharge hole 142 when abutting against the base portion 92C. In addition, the valve portion 140 has a state in which the discharge hole 142 is closed, and can be used in a pneumatic cylinder. The outer diameter of the gap in the radial direction is set between 12B.

The sealing member 81C communicates between the lubricant holding chamber 83C and the rod guide 15 via a discharge path (discharge mechanism) 143 in the discharge hole 142 in a state where the valve portion 140 does not abut against the base portion 92C. Thereby, at the time of assembly to be described later, the opening portion 22 before the rod guide 15 is disposed in the lubricant holding chamber 83C and the pneumatic cylinder 12B via the discharge passage 143 can be left in the sealing member 81C and the sliding member 121. The residual air in the lubricant holding chamber 83C is discharged to the outside of the lubricant holding chamber 83C. In other words, the discharge passage 143 that discharges the residual air formed in the sealing member 81C and the valve portion 140 that is integrally formed with the sealing member 81C and closes the discharge passage 143 are discharged, and the residual air remaining in the lubricant holding chamber 83C is discharged during assembly. After the discharge, the lubricant holding chamber 83C is sealed.

Next, an assembly process of assembling the gas spring of the third embodiment described above will be described.

First, as shown in FIG. 10, the pneumatic cylinder 12B in a state in which the opening-side locking portion 26 shown in FIG. 9 is not formed is prepared. The pneumatic cylinder 12B is held in a vertical posture in which the lid portion 23 is positioned on the lower side. Further, the piston rod 14 in a state in which the piston 13 is attached in advance with the piston 13 as the lower side is inserted into the pneumatic cylinder 12B from the upper opening portion 22. At this time, the piston 13 is inserted into position in the previously set range with respect to the pneumatic cylinder 12B. Further, at this time, in the main shaft portion 55 of the piston rod 14, the sliding member 121, the sealing member 81C, and the rod guide 15 are arranged in advance from the piston 13 side at a position away from the piston 13.

Next, the sliding member 121 is inserted into the pneumatic cylinder 12B from the opening portion 22. At this time, the sliding member 121 is inserted into the pneumatic cylinder 12B. It is located at a predetermined sliding member reference position set in advance. In this state, the sliding member 121 is in close contact with the inner circumferential surface of the pneumatic cylinder 12B by the seal ring 129, and is in close contact with the piston rod 14 by the seal ring 130.

Next, a predetermined amount of the lubricant L set in advance is injected from the opening 22 to the upper side of the sliding member 121 in the pneumatic cylinder 12B. Then, the lubricant L is stored in the pneumatic cylinder 12 by the gravity on the sliding member 121 which becomes the lower side. At this time, as described above, since the sliding member 121 is in close contact with the piston rod 14 and the pneumatic cylinder 12, the lubricant L does not leak to the lower side than the sliding member 121.

Next, as shown in FIG. 11A, the sealing member 81C in a state in which the valve portion 140 is the upper side is inserted into the pneumatic cylinder 12B from the opening portion 22. In the meantime, while the sliding member 121 is maintained in the above-described state of the sliding member reference position, the sealing member 81C is inserted into the position of the predetermined sealing member arrangement position set in advance with respect to the pneumatic cylinder 12B. Then, after fitting in the pneumatic cylinder 12B, the sealing member 81C discharges the residual air with the liquid surface of the lubricant L to the opening 22 side via the discharge path 143. Further, when the sealing member 81C is positioned at the position where the sealing member is disposed, the residual air between the liquid surface and the liquid surface is completely discharged, and the upper surface of the base portion 92C is lower than the liquid level of the lubricant L by a predetermined amount.

Then, as shown in FIG. 11B, the rod guide 15 in a state in which the large diameter portion 73 is lower in advance is pressed into the pneumatic cylinder 12B from the opening portion 22. At this time, the rod guide 15 is pressed into place at a predetermined position of the rod guide arrangement set in advance. Then, the rod guide 15 abuts against the valve portion 140 of the sealing member 81C, deforms the valve portion 140, and abuts against the base portion 92C to block all discharges. Road 143. At this time, the lubricant L overflowing to the upper side of the base portion 92C is a gap formed between the chamfering on the inner peripheral side of the sealing member 81C and the piston rod 14 and between the valve portion 140 and the pneumatic cylinder 12B. The gap formed.

Then, the opening portion 22 side of the pneumatic cylinder 12B is plastically deformed by the rolling process, and as shown in FIG. 9, the opening-side locking portion 26 is formed in a predetermined range from the end portion to the axial direction set in advance. The end surface of the large diameter portion 73 of the rod guide 15 on the tapered portion 74 side is locked to the opening side locking portion 26, and the rod guide 15 is prevented from falling off from the pneumatic cylinder 12B.

As in the above manner, the assembly work of the gas spring is completed.

According to the third embodiment described above, the discharge mechanism 143 that discharges the residual air remaining in the lubricant holding chamber 83C during the closing assembly and the restriction mechanism that restricts the leakage of the lubricant from the lubricant holding chamber 83C is The valve member 140 is integrally provided by the sealing member 81C. Therefore, the number of parts can be reduced, and assembly becomes easy.

The embodiment described above includes a pneumatic cylinder in which an operating gas is sealed and at least one end thereof is open, a piston slidably inserted into the pneumatic cylinder, and a piston connected to the outside of the pneumatic cylinder. a piston rod; and a rod guide provided on one end side of the pneumatic cylinder, between the piston and the rod guide, an annular sealing member that slides with the piston rod; and the piston and the piston a sliding member that is axially slidable in the pneumatic cylinder; and a lubricant retaining chamber that is sealed with a lubricant between the sliding member and the sealing member, and is provided with the sealing member In the case of the above sliding member, the discharge mechanism that remains residual air in the lubricant holding chamber is discharged. So, in the piston and A sealing member and a sliding member are disposed between the rod guides, and a lubricant holding chamber is provided between the rod guides, and a discharge mechanism for discharging residual air remaining in the lubricant holding chamber during assembly is provided in the sealing member or the sliding member, so that the residue is left The air is exhausted and the lubricant holding chamber can be filled with lubricant. Thereby, even if the piston rod does not move, and even if it is provided in any orientation, the lubricant can be brought into contact with the sealing member and the sliding member, and the wetted state can be maintained, so that the sealing member and the sliding member can be caused. Leakage of the operating gas caused by drying. Therefore, high airtightness can be maintained.

Further, the discharge mechanism is provided in the sliding member to form a feature that communicates with the lubricant holding chamber and the pneumatic cylinder. Therefore, in the case where the residual air is discharged during assembly, for example, if the lubricant leaks from the lubricant holding chamber, the leaking end may be leaked out of the gas spring in the pneumatic cylinder in which the operating gas is sealed. Therefore, leakage of the lubricant to the outside of the gas spring can be suppressed.

Further, the discharge mechanism is provided on an inner circumference or an outer circumference of the sliding member, and constitutes a front end by a lip extending toward the piston side. Therefore, the residual air can be discharged with a simple configuration. Therefore, the cost can be reduced.

Further, the sliding member is composed of a sliding portion formed of a material which is soft with the inner circumference of the pneumatic cylinder and the piston rod, and a non-sliding portion formed of a material harder than the sliding portion. The piston rod is provided with a restricting means for restricting the movement of the sliding member in the axial direction. When the restricting means abuts against the sliding member, the restricting means abuts against the non-sliding portion. In this way, the piston rod is provided by the restriction means for abutting the movement of the sliding member in the axial direction, and is abutted against the hard member by the sliding member. Since the material is formed as a non-sliding portion, damage to the sliding portion formed by the soft material that abuts against the inner circumference of the pneumatic cylinder and the piston rod can be suppressed.

Further, after the air cylinder is assembled, the movement restricting means for preventing the restriction means from abutting against the sliding member is formed. Therefore, when the gas spring is actuated, the restricting means pushes the sliding member, and the lubricant does not leak from the lubricant holding chamber. Therefore, the lubricant can be well maintained in the lubricant retaining chamber.

Further, the discharge mechanism is constituted by a discharge path that discharges the residual air, and a closing mechanism that closes the discharge path. Therefore, the residual air remaining in the lubricant holding chamber during assembly is discharged via the discharge path, and then the discharge path is closed by the closing mechanism to suppress leakage of the lubricant from the lubricant holding chamber. Therefore, it is possible to more reliably perform the leakage of the residual air and the leakage of the lubricant after the discharge.

Further, the discharge passage is provided in the sealing member to form a communication between the lubricant holding chamber and the rod guide. Therefore, there is no need to reverse the assembly process. Therefore, the assembly work becomes easier.

Further, the closing mechanism is an annular plate that is held between the sealing member and the rod guide. Therefore, the leakage of the lubricant from the lubricant retaining chamber can be more reliably restricted.

Further, since the closing mechanism is provided integrally with the sealing member, the number of parts can be reduced, and assembly can be easily performed.

Further, since the sealing means is provided between the rod guide and the pneumatic cylinder, it is possible to suppress the lubricant introduced into the gap between the closing mechanism and the pneumatic cylinder. External leakage.

Further, in the above-described embodiment, the gas cylinder of the present invention is described by taking a gas spring in which a compressed gas is sealed in a pneumatic cylinder. However, a gas type buffer for not using a spring may be used. Sexual gas pressure cylinder.

G‧‧‧dry gas

12‧‧‧ pneumatic cylinder

16‧‧‧Installation bracket

21‧‧‧胴

23‧‧‧ 盖部

25‧‧‧Cylinder

28‧‧‧Open side cylinder

30‧‧‧Insert hole

35‧‧‧ joint plate

36‧‧‧Installation board

37‧‧‧Protruding

38‧‧‧Installation holes

43‧‧‧through holes

44‧‧‧ Shallow hole

45‧‧‧ Shallow hole

46‧‧‧ Sealed ditch

47‧‧‧ access hole

50‧‧‧ air chamber

51‧‧‧ air chamber

55‧‧‧Spindle Department

58‧‧‧Piston fitting shaft

59‧‧‧捻口

81‧‧‧ Sealing members

82‧‧‧Sliding members

86‧‧‧ Covering the core

87‧‧‧ Sealing Department

88‧‧‧Parts Department

89‧‧‧ wall

92‧‧‧ base

93‧‧‧Outer tubular part

94‧‧‧Inside cylindrical part

98‧‧‧High-strength part (non-sliding part)

99‧‧‧Sliding section

L‧‧‧Lubricant

G’‧‧‧ residual air

13‧‧‧Piston

14‧‧‧ piston rod

15‧‧‧ rod guide

22‧‧‧ Openings

26‧‧‧Open side locking

27‧‧‧ annular convex

29‧‧‧ Cover side cylindrical part

41‧‧‧Piston body

42‧‧‧Seal ring

57‧‧‧Component fitting shaft

63‧‧‧Abutment gasket (restriction means)

64‧‧‧ inserted through hole

65‧‧‧Clocked Disc Department

66‧‧‧Intermediate tubular part

67‧‧‧Abut the flange

67A‧‧‧Abutment flange

71‧‧‧Rod guide body

72‧‧‧Sliding bushing

73‧‧‧The Great Trails Department

74‧‧‧ Cone

76‧‧‧ Large diameter hole

77‧‧‧Small hole

82A‧‧‧Sliding members

83‧‧‧Lubricant holding room

83A‧‧‧Lubricant holding room

98A‧‧‧High Strength Department

99A‧‧‧Sliding Department

100‧‧‧ Main Department

100A‧‧‧ Main Department

101‧‧‧Link Department

101A‧‧‧Link Department

102‧‧‧Lip

102A‧‧‧Lip

12B‧‧‧ pneumatic cylinder

21B‧‧‧胴

25B‧‧‧Cylinder Department

51B‧‧‧ air chamber

63A‧‧‧Abutment gasket

66A‧‧‧Intermediate tubular part

81C‧‧‧ Sealing member

83B‧‧‧Lubricant holding room

83C‧‧‧Lubricant holding room

86C‧‧‧ core

87C‧‧‧ Sealing Department

88C‧‧‧Parts Department

92C‧‧‧ Base

110‧‧‧ rod guide

111‧‧‧Great Path Department

112‧‧‧Intermediate diameter

113‧‧‧Little Trails Department

115‧‧‧ Sealed ditch

116‧‧‧through holes

117‧‧‧Seal ring

119‧‧‧ Sealing members

120‧‧‧Sand gasket

121‧‧‧Sliding members

125‧‧‧Exhaust hole

128‧‧‧Sliding component body

129‧‧‧Seal ring

130‧‧‧Seal ring

132‧‧‧ Sealed ditch

133‧‧‧ Sealed ditch

135‧‧‧discharge road

140‧‧‧Valves

142‧‧‧Exhaust hole

143‧‧‧Discharge road

Fig. 1 is a cross-sectional view showing a gas spring of a pneumatic cylinder device according to a first embodiment of the present invention.

Fig. 2A is a cross-sectional view showing the front stage of the assembly process of the gas spring of the first embodiment in order.

Fig. 2B is a cross-sectional view showing the front stage of the assembly process of the gas spring of the first embodiment in order.

Fig. 2C is a cross-sectional view showing the front stage of the assembly process of the gas spring of the first embodiment in order.

Fig. 3A is a cross-sectional view showing a rear stage of an assembly process of a gas spring according to the first embodiment.

Fig. 3B is a cross-sectional view showing a rear stage of the assembly process of the gas spring of the first embodiment.

Fig. 3C is a cross-sectional view showing a rear stage of the assembly process of the gas spring of the first embodiment.

FIG. 4 is a cross-sectional view of a main part showing a state in the middle of assembly of the gas spring of the first embodiment.

Fig. 5 is an assembly showing a modification of the gas spring of the first embodiment; A cross-sectional view of the main part of the state in the middle.

Fig. 6 is a cross-sectional view showing a gas spring of a pneumatic cylinder device according to a second embodiment of the present invention.

Fig. 7 is a cross-sectional view showing an initial stage of assembly work of a gas spring according to a second embodiment.

Fig. 8A is an enlarged cross-sectional view showing the assembly work after the initial stage of the assembly process of the gas spring of the second embodiment.

8B is an enlarged cross-sectional view showing the assembly work after the initial stage of the assembly process of the gas spring of the second embodiment.

Fig. 9 is a cross-sectional view showing a gas spring of a pneumatic cylinder device according to a third embodiment of the present invention.

Fig. 10 is a cross-sectional view showing an initial stage of an assembly process of a gas spring according to a third embodiment.

Fig. 11A is an enlarged cross-sectional view showing the assembly work after the initial stage of the assembly process of the gas spring of the third embodiment.

Fig. 11B is an enlarged cross-sectional view showing the assembly work after the initial stage of the assembly process of the gas spring of the third embodiment.

26‧‧‧Open side locking

74‧‧‧ cone

73‧‧‧The Great Trails Department

81‧‧‧ Sealing members

82‧‧‧Sliding members

25‧‧‧Cylinder

13‧‧‧Piston

12‧‧‧ pneumatic cylinder

23‧‧‧ 盖部

14‧‧‧ piston rod

15‧‧‧ rod guide

22‧‧‧ Openings

72‧‧‧Sliding bushing

71‧‧‧Rod guide body

93‧‧‧Outer tubular part

92‧‧‧ base

94‧‧‧Inside cylindrical part

99‧‧‧Sliding section

98‧‧‧High-strength part (non-sliding part)

67‧‧‧Abut the flange

63‧‧‧Abutment gasket (restriction means)

G’‧‧‧ residual air

L‧‧‧Lubricant

102‧‧‧Discharge agencies

83‧‧‧Lubricant holding room

30‧‧‧Insert hole

50‧‧‧Dry gas introduction into the air chamber

29‧‧‧ Cover side cylindrical part

27‧‧‧ annular convex

28‧‧‧Open side cylinder

Claims (7)

A pneumatic cylinder device comprising: a pneumatic cylinder in which an actuating gas is sealed and at least one end is an opening; a piston slidably inserted into the pneumatic cylinder; and the piston is coupled to the outside of the pneumatic cylinder a piston rod; and an open end side of the piston cylinder for guiding the rod guide of the piston rod, and between the piston and the rod guide, an annular ring sliding with the piston rod a sealing member; between the sealing member and the piston, a sliding member that is slidable in the pneumatic cylinder in the axial direction, and that blocks a gap between the pneumatic cylinder and a gap between the piston rod; and a lubricant holding chamber in which a lubricant is sealed between the sliding member and the sealing member, and a discharge mechanism that discharges residual gas remaining in the lubricant holding chamber during assembly is provided in the sealing member or the sliding member; the discharge mechanism Provided on the inner circumference or the outer circumference of the sliding member, and forming a front end by a lip extending toward the piston side; the lip is deformed to communicate with the lubricant Chamber and the pressure cylinder. The pneumatic cylinder device according to claim 1, wherein the sliding member is a sliding portion formed of a soft material that is in sliding contact with an inner circumference of the pneumatic cylinder and the piston rod, and a sliding portion a non-sliding portion formed of a harder material, wherein the piston rod is provided with a restricting means for restricting movement of the sliding member in the axial direction, and the restricting means and the non-sliding when the restricting means abuts against the sliding member The department abuts. The pneumatic cylinder device according to claim 2, wherein the pneumatic cylinder is formed with a movement restricting means for preventing the restriction means from abutting against the sliding member after assembly. A pneumatic cylinder device comprising: a pneumatic cylinder in which an actuating gas is sealed and at least one end is an opening; a piston slidably inserted into the pneumatic cylinder; and the piston is coupled to the outside of the pneumatic cylinder a piston rod; and an open end side of the piston cylinder for guiding the rod guide of the piston rod, and between the piston and the rod guide, an annular ring sliding with the piston rod a sealing member; between the sealing member and the piston, a sliding member that is slidable in the pneumatic cylinder in the axial direction, and that blocks a gap between the pneumatic cylinder and a gap between the piston rod; and a lubricant holding chamber in which a lubricant is sealed between the sliding member and the sealing member, and a discharge mechanism that discharges residual gas remaining in the lubricant holding chamber during assembly is provided in the sealing member or the sliding member; The discharge mechanism is provided in the sealing member, and is configured to communicate between the lubricant holding chamber and the rod guide, and a discharge passage for discharging the residual air and a closing mechanism for closing the discharge passage. The pneumatic cylinder device according to claim 4, wherein the closing mechanism is an annular plate that is held between the sealing member and the rod guide. The pneumatic cylinder device according to claim 4, wherein the closing mechanism is provided integrally with the sealing member. The pneumatic cylinder device according to claim 4, wherein a sealing means is provided between the rod guide and the pneumatic cylinder.