JP2010012748A - Material feeding device for injection molding apparatuses - Google Patents

Abstract

[PROBLEMS] To reduce friction caused by a resin material between a heating cylinder and a molding machine screw and a contact prevention means, reduce a physical load on an apparatus, perform stable weighing, and remove a supplied resin material. Provided is a material supply device for an injection molding machine capable of preventing interference of gas flow.
A guide pipe 16 is divided into a guide pipe 16 in which a vent hole 17 is formed, a space 16a that does not communicate with the vent hole 17, and a space 16b that communicates with the vent hole 17. And a shielding plate 19 attached to the inner wall of the machine, and the shielding plate 19 is disposed in the supply path 20 in a direction intersecting the axial direction of the molding machine screw 15. The shielding plate 19 of the contact preventing means 10 divides the inside of the supply path 20 so that the space 16a side becomes the resin supply path 20a and the space 16b side becomes the vacuum path 20b.
[Selection] Figure 2

Description

  The present invention provides a material supply device for an injection molding machine that can stably supply a resin material to an injection molding machine and efficiently remove gaseous moisture, resin deposits, and resin decomposition products generated from the resin. About.

  In the injection molding, moisture and chemical substances contained in the resin material are gasified to cause various defects such as resin melting and bubbles in the molded product. Therefore, it is necessary to dry the resin material to be used at a predetermined temperature for several hours in advance to remove moisture and resin deposits. However, these processes have increased the time and labor load required for preparation for molding, and have been a factor for lowering the production efficiency when molding a product.

  In order to remedy this problem, as an incidental device of an injection molding machine that omits the resin material drying process, a space is provided in the cylinder by limiting the amount of resin material supplied, and moisture and gas generated from the resin are removed by suction. There is a material supply device having a deaeration performance provided with a mechanism for performing the above operation.

  As this type of apparatus, there is one proposed in Patent Document 1. FIG. 4 shows a schematic view of a pellet supplier disclosed in Patent Document 1. In FIG. This pellet supply body includes a resin material storage body for supplying a resin material to an injection molding machine, a feed screw for cutting out a predetermined amount of resin material from the storage body to a heating cylinder, and a heating cylinder. A contact prevention device is provided to prevent the resin material supplied to the resin material supply portion from contacting the removed moisture or gas.

  Next, the operation of the apparatus disclosed in Patent Document 1 will be described. The resin material is once stored in the resin material storage body and then cut out by a feed screw only at the time of measurement or from a heating cylinder inlet to a certain height and is supplied into the heating cylinder. The supplied resin material is melted by the screw in the heating cylinder, and the gas generated so far passes through the screw or the resin material in the heating cylinder and is sucked and removed from the vacuum port by the vacuum pump. At that time, if the resin material supply position and the vacuum port position exist in the same space, there is a problem that the gas to be removed reattaches to the resin material and the deaeration effect is lowered. Therefore, a tubular contact prevention device is installed, and contact between the resin material and gas is prevented by using the inside of the contact prevention cylinder as a resin material supply path and the outside as a vacuum path.

In Patent Document 2, a sliding plate having a rectangular sliding surface having a long side and a short side provided in a dropping port formed in a bracket fixed to a heating cylinder, and provided on a wall surface of the dropping port. A mechanism for supplying a molded resin material having a suction port for evacuating the inside of the heating cylinder is disclosed. A suction port is perforated on the side surface of the bracket so that air, gas, and the like in the heating cylinder communicating with the drop port can be sucked. The sliding plate has a gap between the short side of the lower end and the wall surface of the drop opening for limiting the amount of the drop of the molding resin material so that the molding resin material at the drop opening during screw rotation substantially covers the lead surface of the screw. In order to occur, the short side of the sliding surface is provided so as to coincide with the screw axis direction. With the sliding plate, stable plasticization is enabled by allowing the molding resin material at the drop opening when the screw rotates to substantially cover the lead surface of the screw. The sliding plate has a function as a contact prevention means for preventing the resin material supplied to the resin material supply portion to the heating cylinder from being removed from the moisture or gas due to its shape and arrangement.
Japanese Patent No. 3786972 JP 2007-76058 A

  However, in the material supply device having the above-described configuration, the resin material supplied into the heating cylinder is sandwiched between the contact-preventing cylinder or the sliding plate parallel to the screw shaft and the screw, and the cylinder due to friction caused by the rotation of the screw. There is concern about wear of the body and screw. In addition, this may pulsate the amount of resin material supplied to the tip of the heating cylinder, which may prevent stable measurement. Further, when the contact preventing means is a cylinder, the installation of the material supply device is restricted by the size of the heating cylinder inlet of the injection molding machine, and the application scale is limited.

  Therefore, the present invention reduces the friction caused by the resin material between the heating cylinder and the molding machine screw and the contact preventing means, reduces the physical load on the apparatus, performs stable weighing, and supplies the resin. It is an object of the present invention to provide a material supply device for an injection molding machine capable of preventing interference between the material and the flow of gas to be removed.

  In order to achieve the above object, the material supply device for an injection molding machine of the present invention is a resin material supplied from a hopper into a heating cylinder in which a screw is rotatably accommodated, in a direction perpendicular to the heating cylinder. In a material supply apparatus for an injection molding machine that drops and supplies a formed supply path, a guide pipe in which a vent hole is formed, and a space that does not communicate with the vent hole and the vent hole communicate with the inside of the guide pipe. A shielding plate attached to the inner wall of the guide pipe, and the shielding plate is disposed in the supply path in a direction crossing the axial direction of the molding machine screw, By the shielding plate 19, the space side that is not in communication with the vent hole serves as a resin supply path for dropping the resin material, and the space side that is in communication with the vent hole is made from the resin material kneaded by the molding machine screw. Let the generated gas pass through Characterized in that it is divided so that the vacuum path for.

  The contact prevention means of the material supply apparatus of this invention has arrange | positioned the shielding board in the direction which cross | intersects the axial direction of a screw. This prevents friction caused by the resin material between the heating cylinder and the molding machine screw and the contact prevention means, reduces the physical load on the contact prevention means, performs stable weighing, and supplies the resin material. It becomes possible to prevent interference of the flow of the removed gas.

  Further, the shielding plate may extend in a direction orthogonal to the axial direction of the molding machine screw.

  Further, the resin supply path may be disposed in front of the injection path of the molding machine screw of the injection molding machine with respect to the vacuum path.

  In addition, the supply path connects the first screw hole formed in the feed screw casing having a feed screw that conveys a predetermined amount of the resin material supplied from the hopper, and connects the feed screw casing and the heating cylinder. The shielding plate may extend in the vertical direction from the lower part of the feed screw to the upper part of the molding machine screw.

  According to the present invention, the resin material that prevents friction caused by the resin material between the heating cylinder and the molding machine screw and the contact prevention means, reduces the physical load on the apparatus, performs stable weighing, and is supplied. It is possible to prevent interference between the removed gas flow.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a side sectional view showing an outline of an injection molding machine provided with a material supply apparatus of the present embodiment. FIG. 2 is a transparent perspective view of the material supply apparatus of this embodiment. Note that only a part of the feed screw housing 6 and the visible block 11 shown in FIG. 2 are shown. FIG. 3 is a three-side view of the material supply apparatus of the present embodiment.

  The injection molding machine includes a material supply device that supplies a resin material to the heating cylinder 14 and a heating cylinder 14 in which a molding machine screw 15 is rotatably accommodated. The material supply device includes a hopper portion A that stores a resin material, a feed portion B that supplies a predetermined amount of resin material to a supply path 20 that will be described later, and a connection portion C that connects the feed portion B and the heating cylinder 14. And contact preventing means 10 disposed in the feed part B and the connection part C.

  The hopper part A includes a first hopper 1, a second hopper 3 disposed below the first hopper 1, and a valve 2 between the first hopper 1 and the second hopper 3.

  The feed part B includes a feed screw housing 6, a feed screw 5, a feed motor 4 and a vacuum pump 8.

  The feed screw housing 6 rotatably holds the feed screw 5 in a first hole 6a formed in the horizontal direction. Further, the feed screw housing 6 is formed with a second hole 6b communicating with the first hole 6a for dropping the resin material supplied from the feed screw 5 in the vertical direction. A vacuum port 7 is formed in the second hole 6 b, and the vacuum port 7 is connected to a vacuum pump 8. The vacuum pump 8 can make the space from the first hopper 1 and the second hopper 3 to the heating cylinder 14 into a vacuum state. The feed screw 5 is rotationally driven by the feed motor 4 under conditions set only during weighing, and sends a certain amount of the resin material supplied from the hopper part A to the second hole 6b.

  The connection part C is a part for connecting the feed part B and the heating cylinder 14 for supplying the resin material from the feed part B to the heating cylinder 14. The visible block 11, the intermediate flange 12, and the heating cylinder And an inlet 13. The visible block 11 is disposed below the feed screw housing 6, and the heating cylinder inlet 13 is disposed above the heating cylinder 14. The visible block 11 can visually check how the resin material is fed, and includes a resin supply sensor 9 for preventing an excessive supply of the resin material by the feed screw 5. The intermediate flange 12 is disposed between the visible block 11 and the heating cylinder 14. The visible block 11, the intermediate flange 12 and the heating cylinder inlet 13 all have a hollow structure and form a connection hole 11b. The connection hole 11b communicates with the second hole 6b and the inside of the heating cylinder 14, and is a hole formed in the vertical direction similarly to the second hole 6b. A supply path 20 for supplying the resin material from the hopper portion A into the heating cylinder 14 is constituted by the second hole 6b and the connection hole 11b.

  The contact prevention means 10 includes a guide pipe 16 provided with a vent hole 17, a flat plate 18 that fixes the contact prevention means 10 in the vertical direction, and a shielding plate 19 that guides resin and separates the vacuum path.

  The guide tube 16 has a shielding plate 19 attached to the inner wall portion and a through hole 17 formed therethrough. The shielding plate 19 divides the inside of the guide tube 16 into a space 16 a not communicating with the vent hole 17 and a space 16 b communicating with the vent hole 17. The ventilation hole 17 is a hole for evacuating the inside of the vacuum path 20b described later, and penetrates toward the ground direction of the molding machine screw 15.

  A hole having the same diameter as the outer shape of the guide tube 16 is formed at the center of the flat plate 18, and the guide tube 16 is fixed to the hole. The flat plate 18 is arranged in a direction intersecting the supply path 20, that is, in the horizontal direction. The outer peripheral shape of the flat plate 18 may be circular, but is preferably a polygonal shape in order to prevent the contact preventing means 10 from shifting in the horizontal direction. The flat plate 18 is positioned on the upper surface of the visible block 11 and is sandwiched by the feed screw housing 6 to determine the vertical position of the contact prevention means 10 (judged from the drawing. Please judge).

  The shielding plate 19 is a single plate member having a curved curved portion 19a and a vertical portion 19b provided continuously with the curved portion 19a. The bending portion 19 a is fixed in the guide tube 16 and is bent from the upper end portion of the guide tube 16 toward the lower side of the guide tube 16. A part of the vertical portion 19 b is also fixed in the guide tube 16. The vertical portion 19 b extends in the vertical direction in the supply path 20 toward the heating cylinder 14 in a direction orthogonal to the axial direction of the molding machine screw 15. With the contact preventing means 10 positioned by the flat plate 18, the shielding plate 19 extends in the vertical direction from below the feed screw 5 to above the molding machine screw 15. With this shielding plate 19, the space 16 a side that is not in communication with the vent hole 17 in the supply path 20 becomes a resin supply path 20 a for dropping the resin material, and the space 16 b side in communication with the vent hole 17 is on the molding machine screw. 15 is divided so as to be a vacuum path 20b for allowing a gas generated from the resin material kneaded in 15 to pass therethrough.

  The end portion 19c in the width direction of the shielding plate 19 is in contact with the inner wall of the supply path 20, whereby the supply path 20 is vertically divided into two in the forward and backward directions in the injection direction, that is, the resin supply path 20a and the vacuum path. 20b. FIG. 3A shows a situation in which the width direction end portion 19 c of the shielding plate 19 is in contact at two points A and B on the inner wall surface of the guide tube 16. As shown in FIGS. 3A and 3B, the vertical portion 19b of the shielding plate 19 is arranged on the rear side in the injection direction in the guide tube 16, and as a result, the resin supply path 20a is wider than the vacuum path 20b. However, the position of the vertical portion 19b may be located more forward in the injection direction as long as the resin material does not block the supply path 20. However, regardless of the position of the vertical portion 19b, the vertical portion 19b is made to cross the axial direction of the molding machine screw 15, preferably orthogonal.

  The shape of the lower end portion 19d of the vertical portion 19b is shown as a straight shape in FIG. 3B, but the present invention is not limited to this. Although the shielding plate 19 is installed immediately below the feed screw 5, the shape of the lower end portion 19 d of the shielding plate 19 is formed in a cross section of the molding machine screw 15 so that the shielding plate 19 is the longest without contacting the molding machine screw 15. You may form in the shape along.

  Next, operation | movement of the material supply apparatus of this embodiment is demonstrated.

  The resin material is first sent to the first hopper 1 in the atmospheric pressure state by a vacuum pump and stored. The first hopper 1 is a buffer hopper whose internal pressure is intermittently switched between atmospheric pressure and vacuum pressure. Next, the internal pressure of the first hopper 1 is set to a vacuum pressure state. The second hopper 3 is always in a vacuum pressure state. The resin material in the first hopper 1 is dropped into the second hopper 3 by opening the valve 2. After the valve 2 is closed, the first hopper 1 returns to the atmospheric pressure state, but the second hopper 3 still maintains the vacuum pressure.

  The resin material supplied from the second hopper 3 to the feed screw 5 is sent to the second hole 6b. The supply amount of the resin material is adjusted according to the setting conditions of the feed screw 5. That is, ON / OFF of the feed motor 4 is controlled by a plasticizing signal or a resin supply sensor 9 at the time of injection molding. Thereby, supply of an excessive resin material into the heating cylinder 14 can be prevented and the stability of the supply amount can be maintained.

  The resin material sent into the second hole 6 b, that is, into the supply path 20 falls in the supply path 20 toward the heating cylinder 14. That is, the resin material is supplied into the heating cylinder 14 through the visible block 11, the intermediate flange 12, and the heating cylinder inlet 13.

  The resin material falls toward the heating cylinder 14 through the resin supply path 20 a side in the supply path 20. Since the position where the resin material is supplied is forward in the injection direction, the resin material can be efficiently supplied to the molding machine screw 15 without being interfered by the flow of moisture or gas generated from the resin. Therefore, the physical load on the shielding plate 19 can be reduced and the effect can be maintained for a long time.

  In other words, the contact preventing means 10 of the present embodiment is configured such that the vertical portion 19b of the shielding plate 19 is not disposed parallel to the axial direction of the molding machine screw 15, but is disposed in an orthogonal direction. Friction caused by the resin material kneaded around the axis of the screw 15 can be reduced. As a result, the physical load on the vertical portion 19b of the shielding plate 19, that is, the contact preventing means 10, can be reduced. Further, by reducing the occurrence of such friction, it is possible to prevent the occurrence of pulsation of the amount of resin material supplied to the tip of the heating cylinder 14, and thus the resin material can be stably metered. Become.

  Moisture and gas generated from the resin pass through the vacuum path 20 b separated by the shielding plate 19, pass through the vent hole 17, and are discharged to the outside of the guide tube 16. Thereafter, moisture and gas move around the induction tube 16 and are sucked from the vacuum port 7 by the vacuum pump 8. The vacuum pump 8 evacuates the space from the first hopper 1 and the second hopper 3 to the heating cylinder 14 and sucks moisture, gas, etc. existing in the space in the heating cylinder 14. At the same time, since air leaking from the gland portion of the molding machine screw 15 is also sucked, a rapid gas flow is created, and the gas can be efficiently removed.

  As described above, according to the contact prevention means 10 of the present embodiment, moisture and gas generated in the heating cylinder 14 can be efficiently removed by the shielding plate 19, and molding defects such as resin, burns, bubbles, and silver can be improved. it can. Moreover, according to the contact prevention means 10, the friction by the resin material between the heating cylinder 14 and the molding machine screw 15 and the contact prevention means 10 is prevented, and the physical load on the contact prevention means 10 is reduced and stabilized. It is possible to perform metering and to prevent interference between the supplied resin material and the removed gas flow. Furthermore, although the contact prevention means 10 of this embodiment has the plate-shaped shielding board 19, since it is such a simple shape, it prevents contact with a material supply apparatus irrespective of the scale of an injection molding machine. Means can be provided.

It is a sectional side view which shows the outline of the injection molding machine provided with the material supply apparatus of one Embodiment of this invention. It is a permeation | transmission perspective view of the material supply apparatus of one Embodiment of this invention. It is a three-view figure of the material supply apparatus of one Embodiment of this invention. It is a cross-sectional side view which shows an example of the material supply apparatus which has the conventional deaeration performance.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st hopper 2 Valve 3 2nd hopper 4 Feed motor 5 Feed screw 6 Feed screw housing 6a 1st hole 6b 2nd hole 7 Vacuum port 8 Vacuum pump 9 Resin supply sensor 10 Contact prevention means 11 Visible block 11b Connection Hole 12 Intermediate flange 13 Heating cylinder inlet 14 Heating cylinder 15 Molding machine screw 16 Guide pipe 16a Space 16b Space 17 Ventilation hole 18 Flat plate 19 Shielding plate 19a Curved portion 19b Vertical portion 19c Width direction end portion 19d Lower end portion 20 Supply path 20a Resin supply Path 20b Vacuum path A Hopper section B Feed section C Connection section

Claims (4)

The resin material supplied from the hopper (1, 3) is formed in a vertical direction with respect to the heating cylinder (14) into the heating cylinder (14) in which the molding machine screw (15) is rotatably accommodated. In the material supply apparatus for an injection molding machine that drops and supplies the inside of the supply path (20),
The guide pipe (16) in which the vent hole (17) is formed, the space (16a) not communicating with the vent hole (17) and the vent hole (17) in the guide pipe (16). A shielding plate (19) attached to an inner wall of the guide pipe (16), which is divided into a space (16b), and the shielding plate (19) is placed in the supply path (20). Contact prevention means (10) arranged in a direction intersecting the axial direction of the screw (15),
By the shielding plate (19), the space (16a) side that is not in communication with the vent hole (17) in the supply path (20) becomes a resin supply path (20a) for dropping the resin material. The space (16b) side communicating with the pores (17) is divided so as to be a vacuum path (20b) for allowing the gas generated from the resin material kneaded by the molding machine screw (15) to pass therethrough. A material supply device for an injection molding machine.   The material supply device for an injection molding machine according to claim 1, wherein the shielding plate (19) extends in a direction orthogonal to an axial direction of the molding machine screw (15).   The injection according to claim 1 or 2, wherein the resin supply path (20a) is disposed in front of an injection direction of the molding machine screw (15) of the injection molding machine with respect to the vacuum path (20b). Material supply equipment for molding machines. The supply path (20) is a first screw screw housing (6) provided with a feed screw (5) for conveying a predetermined amount of the resin material supplied from the hopper (1, 3). A hole (6a), and a second hole (6b) formed in the connection part (C) connecting the feed screw housing (6) and the heating cylinder (14),
The injection molding machine according to any one of claims 1 to 3, wherein the shielding plate (19) extends in a vertical direction from below the feed screw (5) to above the molding machine screw (15). Material supply equipment.

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