JPH1037989A - Locking device for output shaft - Google Patents

Abstract

PROBLEM TO BE SOLVED: To quickly stop an output shaft so as to secure locking by allowing release of locking while play in a connecting part between a driving shaft and a driven shaft is eliminated in the initial rotation of the driving shaft and allowing locking while play in the connecting part is returned because of reaction in a driving shaft rotation stopping time. SOLUTION: When a motor shaft 11 is stopped, rotation of an output shaft 10 is advanced as against a carrier 15 if inertia on the output shaft 10 side is increased, and a play angle θ is reversed, so that restriction of a pin 27 in a lock ring 21 based on a cam hole 28 of the carrier 15 is released and the pin 27 is returned to the neutral position by means of centrifugal force and the like, the lock ring 21 is shifted to the locking position, a lock side lock claw 25 in the lock ring 21 is geared to a gear 26 whose rotation is restricted, and as a result, the output shaft 10 is stopped immediately. Under this condition, if rotation in the normal/reverse direction from the output shaft 10 side is carried out, a holding plate 22 possessing no play angle θ receives rotational force and transmits the rotational force to the lock ring 21. However, the lock claw 25 is geared to the gear 26, so that the output shaft 10 is prevented from rotating.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lock device for an output shaft that can quickly stop the output shaft when the motor is controlled to stop, for example, on the output shaft that outputs the rotational power of the motor.

[0002]

2. Description of the Related Art For example, when a chuck is attached to an output shaft of a power tool and various tools are attached to perform manual work,
Even if the power switch is controlled to OFF, the output shaft continues to rotate due to the inertial force of the chuck and the tool. If the power tool is released during this rotation, it is very dangerous because the tool is rotating. Therefore, when the power switch is turned off, it is desirable that the output shaft be stopped immediately.

[0003] In the above-mentioned chuck, there is a chuck having a torque-up function for tightening and removing a tool by manually rotating an operation ring without using a chuck handle. When using a chuck with a function, the output shaft of the power tool is free to rotate when the motor power is off, so if you try to manually tighten the chuck, the output shaft also rotates and you cannot tighten it manually. However, it is necessary to fix the output shaft with one hand, and there is a problem that the operability is deteriorated because the operation of manually tightening the chuck and holding the tool is required. Therefore, the output shaft of the power tool is
At the time of F, it is desirable that the lock is applied.

[0004]

According to the present invention, when the output shaft is controlled to stop, the output shaft is stopped immediately, and when the output shaft is stopped, the output shaft is locked so as not to rotate. It is another object of the present invention to provide a lock device for an output shaft in which a lock can be operated reliably and a lock can be smoothly released.

[0005]

According to the present invention, an output shaft is formed by connecting a drive shaft and a driven shaft, and a connecting portion for connecting the drive shaft and the driven shaft has a predetermined angle in a mutual rotation direction. Forming a play in which the divided power is not transmitted, fixing a holding plate on the driven shaft side facing the drive shaft in the axial direction, and fixing a locking member having a locking claw on the holding plate to a radially outer locking position. And an inner lock release position so that the lock member moves to the lock position, and when the lock member moves to the lock position, the lock member engages with the lock claw to lock the rotation. A fixing member formed with a claw is provided oppositely, and on the drive shaft side facing the lock member in the axial direction,
While the play of the connecting portion is lost by the initial rotation of the drive shaft, the lock member is allowed to move to the unlock position,
Further, the lock device of the output shaft is provided with a lock operation member that allows the lock member to move to the lock position while the play of the connection portion is restored by the reaction when the rotation of the drive shaft stops. It is characterized by.

[0006] Further, a pin is formed on one of the lock member and the lock operation member and a cam surface is formed on the other, and the cam surface is formed so that the play of the connecting portion is eliminated by the initial rotation of the drive shaft. A lock device for an output shaft formed on a cam surface for moving a lock member to a lock position by contacting the pin.

Further, the present invention is a lock device for an output shaft in which a torque limiter is formed by holding the fixing member rotatably on a fixing portion and pressing and fixing the fixing member with a predetermined load. The output shaft lock device is characterized in that the fixing member is rotatably held by a fixing portion, and the fixing member is pressed and fixed with a predetermined load to form a brake.

[0008]

According to the present invention, when the drive shaft constituting the output shaft is driven by, for example, a motor, the play of the connecting portion between the drive shaft and the driven shaft is eliminated at the initial stage of the rotation.
The lock operation member is allowed to move the lock member to the lock release position, and the lock member is rotated at the unlock position by a subsequent continuous drive, so that the lock is not locked. As a result, the drive shaft rotates the driven shaft by driving the motor,
Output occurs on the output shaft.

Next, when the driving of the drive shaft is stopped (for example, the motor is turned off), the rotation of the driven shaft precedes the drive shaft due to the inertial rotation of the driven shaft. Play returns. During this return, the lock operation member allows the lock member to move to the lock position, and the lock claw of the lock member engages with the engagement claw of the fixed member, thereby preventing rotation of the lock member. Since the lock member is not allowed to rotate relative to the holding plate, the above-described blocking of the rotation of the locking member prevents the rotation of the driven shaft, which locks the output shaft and stops the rotation. Become.

[0010]

According to the present invention, when the drive of the output shaft is released (for example, when the motor is turned off), the rotation of the output shaft is locked and the rotation is immediately stopped. When the chuck is attached and various tools are attached and manual work is performed, after the output shaft is released by the above-mentioned lock, even if the power tool is released immediately, the output shaft due to the inertia force of the chuck or tool is released. The rotation is immediately stopped, and there is no danger and safe work can be performed.

Further, in the lock by the lock member, the lock claw and the engagement claw are disengaged from each other in the radial direction of the shaft, and the locking direction is the circumferential direction. When the output shaft is engaged, even if a rotational load is applied to the output shaft, the lock claw is securely maintained without being disengaged by the rotational load, and when the lock is released, The lock is smoothly released without the engagement of the lock claw being bitten by the rotation load of the output shaft, and as a result, the lock reliably and smoothly operates, respectively.

Further, when the output shaft is stopped, the output shaft is already locked as described above. For example, when a chuck having a torque increasing function is used, the output shaft is not tightened when the chuck is manually tightened. Since it does not rotate, manual tightening can be performed easily and securely, and the work of manually tightening the chuck, holding the tool, and the like becomes easy, and the operability is improved.

In addition, since the torque limiter and the brake are formed on the fixed member for preventing the rotation of the lock member, the inertia on the load side connected to the output shaft is too large, and the lock is immediately applied when the drive shaft is released. If there is a fear that the structure will be damaged due to an overload applied to the output shaft side, the structure can be gradually stopped by a torque limiter or a brake, and damage to the structure can be prevented.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described in detail with reference to the drawings. The embodiment shows an example in which the output shaft locking device of the present invention is applied to the output shaft of a hand-type power tool.
1, the output shaft 10 is driven by the rotation of a motor shaft 11 of a motor (not shown), and a lock device including a speed reduction mechanism is interposed between the motor shaft 11 and the output shaft 10.

The above-mentioned motor shaft 11 is communicatively connected to a sun gear 13 of a planetary gear mechanism 12. The above-described planetary gear mechanism includes, in addition to the above-described sun gear 13, a planetary gear 14 that meshes with the sun gear 13, a carrier 15 that supports the planetary gear 14, and an internal gear 1 that meshes with the planetary gear 14.
6. The fixed ring 17 has a deceleration function as is well known, and the deceleration output is output from the carrier 15.

As shown in FIG. 2, a lock device 20 for locking the output shaft 10 includes the carrier 15 described above,
A lock ring 21 opposed to this in the axial direction, two disk-shaped holding plates 22 for holding the lock ring 21 from both sides, and the above-described internal gear 16 for locking the rotation of the lock ring 21 are provided. Make up.

The shaft portion of the carrier 15 and the output shaft 10
The inner ends of the output shaft 10 are connected to each other so as to be able to transmit, and this fitting structure is provided at two positions opposing each other across the axis in a predetermined range in the axis direction of the inner end of the output shaft 10. The connecting surface 23 is formed by forming the peripheral surface into a flat surface, and the carrier 1 fitted with the connecting surface is formed.
As shown in FIG. 3, the connection fitting portion 24 of 5 has a play angle in which transmission is not performed by a predetermined angle θ from the neutral position in the forward and reverse rotation directions.

At the center of the two holding plates 22, 22, there is formed a connecting fitting portion 29 which fits into the connecting fitting portion 23 of the output shaft 10 without play. It rotates integrally with 10. When the carrier 15 is the driving side, the output shaft 10 can be referred to as a driven side.
The above-mentioned holding plates 22, 22 are connected to the above-mentioned carrier 15 on the driving side.
Thus, it is fixed inside the output shaft 10 on the passive side which faces in the axial direction.

Further, as shown in FIG. 3, a cam hole 28 is formed on the inner side surface of the carrier 15 at a position facing the center of the shaft to release the lock state of the lock ring 21. , 28 are formed, and the cam holes 28, 28 are formed.
When the carrier 15 is rotated in the driving direction by inserting pins 27, 27 of a lock ring 21 to be described later, the inner wall surfaces of the cam holes 28, 28 come into contact with the pins 27, 27 to lock them. The ring 21 is moved from the lock position side to the lock release position side.

As shown in FIG. 4, five lock claws 25 are formed on two outer peripheral portions opposed to each other with the axis of the lock ring 21 interposed therebetween. The pins 27, 27 described above are implanted and fixed to the intermediate portions of the five lock claws 25... At one end, and one end thereof extends to the cam holes 28, 28 of the carrier 15 described above. .

When the above-mentioned lock ring 21 is eccentrically moved to one of the lock claws 25... (For example, the upper side in the figure) toward a lock position set outside in the radial direction, the lock claws 25. The lock ring 21 is provided so as to lock the rotation of the lock ring 21 by meshing with a gear 26 (see FIG. 5) formed on the inner peripheral surface of the internal gear 16 described above.

The gear 26 of the internal gear 16 is usually formed in the shape of an internal gear.
The first lock claws 25 are formed in a shape that meshes with the gear 26 described above. When five lock claws 25 are meshed with the gear 26, the five lock claws 25 mesh with uniform contact. In addition, the rotation load at the time of locking can be equally received by the five locking claws 25, and the required strength is obtained.

When the lock pawls 25 are formed as external gears, one of the five lock pawls 25... Strongly contacts one gear 26 of the internal gear 16 to apply a concentrated rotational load. Therefore, the strength of the gear 26 and the lock claws 25 is more required.

The lock claws 25 are connected to the lock ring 21.
The formation at the two opposing positions of not only allows the center ring to shift to the unlock position by centripetal movement when the lock ring 21 is rotated, but also changes the directionality of the lock ring 21 during assembly. This is to facilitate the assembly by permitting it in two directions, and to enable the use of the lock claw 25 on the opposite side even if the lock claw 25 on one side is inconvenient.

FIG. 6 shows the above-mentioned holding plates 22 and 22, since the two holding plates 22 have the same structure, only one of them is shown. The above-mentioned holding plate 22 has a shaft portion formed with a fitting portion 29 which fits with the connecting fitting portion 23 of the output shaft 10 without play and rotates integrally with the connection fitting portion 23 of the output shaft 10, and further has pins 27, 27 of the lock ring 21. The pin 2
Elongate hole 30, which guides sliding inside and outside of radial direction of 7, 27,
30 are formed.

Therefore, the pin 2 of the lock ring 21
7 and 27 are inserted into the long holes 30 and 30 of the two holding plates 22 and 22 from the left and right, and the lock ring 21 slides between a lock position on the outside in the radial direction and an unlock position on the inside (axial side). Is held possible. The holding plate 22 can hold the lock ring 21 with one of the left and right plates.

As shown in FIG. 7, one of the lock rings 21 (lock side) is provided between the inner peripheral portion of the lock ring 21 and the plane portion of the connection fitting portion 23 of the output shaft 10. A cow horn-shaped spring member 31 for urging the lock claws 25 to the lock position side is interposed.

As shown in FIGS. 1, 2 and 8, in the above-described planetary gear mechanism 12, an internal gear 16 is rotatably supported on a fixed ring 17, and an outer end of the internal gear 16 is provided. Is formed on the uneven surface 40, and the ball 4
By pressing the internal gear 1 against the fixed plate 42 by pressing the internal gear 1 to restrict the rotation thereof, a torque limiter is formed.

The above-mentioned balls 41 are plural (for example, six)
And a fixing member 43 at a position facing the outer end of the internal gear 16. A side of the fixing member 43 facing the internal gear 16 and corresponding to the ball 41 described above. A storage hole 39 is formed at a position where a spring 44 for pressing the above-mentioned ball 41 is stored, and an outer end of the spring 44 is inserted and held by a support pin 46 of a receiving member 45.

A screw 47 is formed on the outer periphery of the fixing member 43 by a square screw.
8 is screwed into the nut 4 so as to move the nut member 48 forward and backward.
9. By moving the receiving member 45 in the axial direction via the ring 50 and adjusting the elasticity of the spring 44,
The above-mentioned ball 41 and the uneven surface 40 of the internal gear 16
, The torque of the torque limiter can be adjusted.

The above-mentioned nut member 48 is connected to the operation cover 51 so that rotation is transmitted in a state where sliding in the axial direction is allowed, for example, by spline fitting. By rotating the cover 51, the nut member 48 can be rotated. Also, the fixing plate 4
2. The fixing ring 17 and the fixing member 43 are integrally connected to each other by an appropriate connection mechanism to be in a fixed state.

The operation of the lock device 20 for the output shaft 10 configured as described above will be described. 1, 7, and 9, the motor shaft 11 is stopped, and the positions of the pins 27, 27 of the lock ring 21 and the cam holes 28, 28 of the carrier 15 are in the center of the cam hole 28 shown in FIG. Since the pin 27 is located at the upper position, the lock ring 21 is urged radially outward by the spring member 31, so that the lock-side gear 25 of the lock ring 21 has its internal rotation restricted. The gear 16 meshes with the gear 26 and is in a locked state.

In this state, if the output shaft 10 is manually turned, for example, in the forward or reverse direction, the carrier 15 has a play angle θ, so that it does not rotate. However, since there is no play angle θ between the holding plate 22 and the holding plate 22, the rotation of the output shaft 10 is received by the holding plate 22, and the holding plate 22 is locked through the elongated hole 30 and the pin 27 of the lock ring 21. The rotational power is transmitted to the ring 21.

However, since the lock claw 25 on the lock side of the lock ring 21 is engaged with the gear 26 of the internal gear 16 whose rotation is restricted by the elasticity of the spring 44 as described above, it is rotated. Nothing. Therefore,
The output shaft 10 is in a locked state, and is prevented from rotating manually.

Since the rotation load applied to the lock claw 25 is circumferential, and the engagement direction of the lock claw 25 is radial, the rotation load causes the lock claw 25 to be disengaged from the gear 26, There is no possibility that it will not be impossible to leave by digging into 26.

When the manual rotation of the output shaft 10 exceeds the elastic force of the spring 44, the internal gear 16 rotates against the pressure of the spring 44, and the torque limiter functions.

As described above, when the rotation of the output shaft 10 is in the locked state, the output shaft 10 does not rotate, so that it is easy to attach a tool to the output shaft 10.

As described above, when the output shaft 10 in the locked state is driven, the motor is driven in this locked state and the motor shaft 11 is rotated in a predetermined driving direction. Canceled automatically.

As shown in FIGS. 10 and 11, the rotation of the motor shaft 11 is reduced by the planetary gear mechanism 12 and output from the carrier 15.
Since the connection fitting portions 23 and 24 have a play angle θ, the rotational power is transmitted to the output shaft 10 after the carrier 15 rotates by the play angle θ.

While the carrier 15 rotates by the play angle θ, the inner wall surfaces of the cam holes 28, 28 of the carrier 15 move the pins 27, 27 of the lock ring 21 to the radially inner lock release position side. . By the action of the cam holes 28, 28, the lock ring 21 shifts to the lock release position on the shaft center side against the spring member 31, and the lock claw 25 is disengaged from the gear 26 of the internal gear 16 to rotate the output shaft 10. Movement is allowed.

In this case, when the rotational force is transmitted to the lock ring 21 (transmission from the holding plate 22 side), the lock ring 21 is formed into a ring having a substantially uniform circumference, so that the rotation thereof causes the lock ring 21 to rotate. The centrifugal force acts to rotate at a position concentric with the output shaft 10, and the lock claw 25 on the outer periphery thereof is
7 does not engage with the gear 26.

As a result, the unlocked state of the lock ring 21 is maintained, and the output shaft 10 is rotated by the driving force of the motor shaft 11. Note that an overload acts on the output shaft 10 while the output shaft 10 is being driven, and this load is
When the elastic force of the internal gear 16 is exceeded,
Rotates against the pressing of the spring 44, and the torque limiter functions.

Next, when the rotation of the motor shaft 11 is stopped by stopping the motor in the driving state, the torque of the motor shaft 11 is reduced, so that the inertia on the output shaft 10 side is increased (the motor shaft 11). 11 recoils), carrier 15
, The rotation of the output shaft 10 precedes, and the play angle θ of the output shaft 10 is reversed, and the pins 27, 27 of the lock ring 21 are formed by the cam holes 28, 28 of the carrier 15.
Is released, the pins 27, 27 are returned to the neutral position by the centrifugal force or the urging force of the spring member 31, and the lock ring 21 is released.
Shifts to the lock position which is the eccentric position side. as a result,
The lock claw 25 on the lock side of the lock ring 21 meshes with the gear 26 of the internal gear 16 whose rotation is restricted,
Locked.

Therefore, when the motor shaft 11 stops, the output shaft 10 stops rotating immediately, and the output shaft 10 does not rotate due to inertia, thereby enhancing safety. When the rotation of the output shaft 10 due to inertia exceeds the elastic force of the spring 44,
The internal gear 16 rotates against the pressing of the spring 44, and the torque limiter functions.

In the above-described embodiment, when the uneven surface 40 on the inner end surface of the internal gear 16 is formed flat and the ball 41 is changed to a brake pad, a brake mechanism can be constructed in that portion, and the aforementioned torque limiter can be formed. Can be configured as a brake mechanism.

In correspondence between the configuration of the present invention and the above-described embodiment, the output shaft, drive shaft and driven shaft of the present invention are:
Corresponding to the motor shaft 11 and the output shaft 10 of the embodiment, similarly, the connection portion corresponds to the connection fitting portions 23 and 24 between the output shaft 10 and the carrier 15, and the lock member corresponds to the lock ring 2.
1, the fixing member having the engaging claw corresponds to the internal gear 16 having the gear 26, and the lock operating member corresponds to the carrier 15 having the cam hole 28. The configuration of the cam surface is as follows: pin 27, cam hole 2
Although corresponding to the configuration of FIG. 8, the present invention is not limited to the configuration of the above-described embodiment, and is applied based on the technical idea of the invention.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a lock device for an output shaft.

FIG. 2 is a partially exploded view of a lock device.

FIG. 3 is a front view of the carrier.

FIG. 4 is a front view of a lock ring.

FIG. 5 is a front view of the internal gear.

FIG. 6 is a front view of a holding plate.

FIG. 7 is a front view showing a locked state of the lock device.

FIG. 8 is an exploded view of a torque limiter mechanism.

FIG. 9 is a sectional view showing a locked state of the lock device.

FIG. 10 is a front view showing the unlocked state of the lock device.

FIG. 11 is a sectional view showing an unlocked state of the lock device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Output shaft 12 ... Planetary gear mechanism 15 ... Carrier 16 ... Internal gear 17 ... Fixing ring 20 ... Locking device 21 ... Lock ring 22 ... Holding plate 23, 24 ... Connection fitting part 25 ... Lock claw 26 ... Gear 27 ... Pin 28: Cam hole 40: Uneven surface 41: Ball 44: Spring

Claims (4)

[Claims] An output shaft is formed by connecting a drive shaft and a driven shaft, and a play is formed at a connecting portion connecting the drive shaft and the driven shaft so that power is not transmitted by a predetermined angle in a mutual rotation direction. Then, a holding plate is fixed to a driven shaft side facing the drive shaft in the axial direction, and a locking member having a locking claw is provided on the holding plate at a radial outer locking position and a radial inner locking position. A fixing member, which is movably held and has an engaging claw that locks the rotation by engaging with the lock claw when the lock member moves to the lock position, is provided on the lock position moving side of the lock member. The lock member is allowed to move to the unlock position while the play of the connecting portion is eliminated by the initial rotation of the drive shaft, on the drive shaft side facing the lock member in the axial direction. Also, the contact when the rotation of the drive shaft is stopped is stopped. While playing the part is restored, the locking device of the output shaft provided with a lock operating member to permit movement of the locking position of the locking member. 2. A pin is formed on one of the lock member and the lock operation member, and a cam surface is formed on the other, and the cam surface is formed so that the play of the connecting portion is eliminated by the initial rotation of the drive shaft. 2. The output shaft lock device according to claim 1, wherein the lock member is formed on a cam surface for moving the lock member to the lock position by contacting the pin. 3. An output shaft according to claim 1, wherein said fixing member is formed in a ring shape and held rotatably on a fixing portion, and said fixing member is pressed and fixed with a predetermined load to form a torque limiter. Locking device. 4. The output shaft according to claim 1, wherein the fixing member is formed in a ring shape and held rotatably on the fixing portion, and the fixing member is pressed and fixed with a predetermined load to form a brake. Locking device.