JP3752513B2 - Output shaft locking device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to, for example, an output shaft locking device that can quickly stop an output shaft when the motor is controlled to stop on an output shaft that outputs the rotational power of the motor.
[0002]
[Prior art]
For example, when a chuck is attached to the output shaft of an electric tool and various tools are attached to perform manual work, the output shaft continues to rotate due to the inertia force of the chuck or tool even if the power switch is turned off. If the power tool is released during this rotation, the tool is rotating, which is very dangerous. Therefore, it is desirable that the output shaft stop promptly when the power switch is turned off.
[0003]
Further, in the above chuck, there is a chuck having a torque-up function for manually tightening and removing the tool by rotating the operation ring without using a chuck handle. When using a chuck, the output shaft of the power tool is free to rotate when the motor power is OFF. Therefore, if you try to tighten the chuck by hand, the output shaft will also rotate and cannot be tightened by hand. It is necessary to fix the output shaft by hand, and there are problems such as manual tightening of the chuck and holding of the tool, resulting in poor operability. Therefore, it is desirable that the output shaft of the electric tool is locked when the motor power is OFF.
[0004]
[Problems to be solved by the invention]
In the present invention, when the output shaft is controlled to stop, the output shaft is quickly stopped, and when the output shaft is stopped, the output shaft can be locked so as not to rotate. An object of the present invention is to provide an output shaft locking device that operates reliably and that unlocks smoothly.
[0005]
[Means for Solving the Problems]
In the present invention, the output shaft is formed by connecting the drive shaft and the driven shaft, and a free angle at which power is not transmitted by a predetermined angle in the mutual rotation direction is formed in the connection portion connecting the drive shaft and the driven shaft. A locking mechanism is provided on the driven shaft side to lock the locking member, which is held by the driven shaft so as to be movable inward and outward in the radial direction, to a fixed member provided on the outer periphery of the locking member; On the drive shaft side facing the lock member in the axial direction, the lock member is moved to the unlocked position while the play angle of the connecting portion disappears by the initial rotation of the drive shaft, and the drive shaft When the rotation of the output shaft is stopped, the output shaft is provided with a lock operation member for operating the lock member to the lock position while the driven shaft is rotated by the free angle of the connecting portion. And
[0006]
Further, a lock claw is formed on the lock member, a locking claw that engages with and disengages from the lock claw is formed on the fixing member, and the lock mechanism is formed by engagement of the lock claw and the locking claw, 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 abutted against the pin while there is no play in the connecting portion due to the initial rotation of the drive shaft. It is an output shaft locking device formed on a cam surface that contacts and moves the locking member to the locking position.
[0007]
Furthermore, it is an output shaft locking device in which a plurality of the locking members are arranged in the circumferential direction of the driven shaft to form a locking mechanism.
Furthermore, the fixing member is rotatably held by a fixing portion, and the output member is a locking device for an output shaft in which the fixing member is pressed and fixed with a predetermined load to form a torque limiter. 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 torque limiter or a brake device for an output shaft.
[0008]
[Action]
According to the present invention, when the drive shaft constituting the output shaft is driven by, for example, a motor, the lock operating member is removed while the play angle of the connecting portion between the drive shaft and the driven shaft disappears in the initial stage of rotation. Moves the lock member toward the unlock position, and the continuous drive after the turn causes the lock member to rotate at the unlock position so that the lock is not applied. As a result, the drive shaft rotates the driven shaft by driving the motor, and an output is generated on the output shaft.
[0009]
Next, when driving of the drive shaft is stopped (for example, motor OFF control), when the driven shaft is rotated by an inertia rotation on the driven shaft side or by manual rotation, a free angle is formed. During the rotation, the lock operation member operates to move the lock member to the lock position, and the lock member is locked in contact with the fixing member, thereby preventing the lock member from rotating. Since this locking member is prevented from rotating with respect to the driven shaft, the above-described rotation prevention of the locking member prevents rotation of the driven shaft, and the output shaft is locked and cannot be rotated.
[0010]
【The invention's effect】
According to this invention, when the drive of the output shaft is stopped (for example, the motor is controlled to be OFF) and the driven shaft side is slightly rotated due to inertia or manually rotated, for example, the output shaft is locked. For example, when a manual operation is performed with a chuck attached to the output shaft and various tools are attached, after the drive of the output shaft is stopped with the lock described above, Even if you let go, the rotation of the output shaft due to the inertial force of the chuck and tool is immediately stopped, so there is no danger and you can work safely.
[0011]
Furthermore, when the output shaft is stopped, it is already locked as described above. For example, when using a chuck having a torque-up function, the output shaft does not rotate when the chuck is manually tightened. Therefore, it is possible to easily and surely perform the hand tightening, and it becomes easy to manually tighten the chuck, hold the tool, etc., thereby improving the operability.
[0012]
Furthermore, when a lock claw is formed on the lock member, and a lock claw is formed on the fixed member by engaging and disengaging the lock claw, the lock claw and the engagement claw are engaged and disengaged in the radial direction of the shaft. In addition, since the locking direction is the circumferential direction, even if a rotational load is applied to the output shaft when the output shaft stops and the locking claw and the engaging claw are engaged, The locked state is securely maintained without disconnection, and when the lock is released, the lock is smoothly released without the engagement of the lock claw being engaged by the rotational load of the output shaft. Each works smoothly and unlocked smoothly.
[0013]
Moreover, the lock | rock intensity | strength can be improved by comprising a plurality of lock members. Furthermore, by configuring a torque limiter or brake on the fixing member that prevents the rotation of the lock member, the inertia on the load side connected to the output shaft is too large, and when the drive shaft is released and the lock is immediately applied, If there is a concern that the output shaft side is overloaded and the structure is damaged, the structure can be gradually stopped with a torque limiter or a brake, and the structure can be prevented from being damaged.
[0014]
【Example】
An 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. In FIG. 1, the output shaft 10 is driven by the rotation of a motor shaft 11 of a motor (not shown). However, a lock device including a speed reduction mechanism is interposed between the motor shaft 11 and the output shaft 10.
[0015]
The motor shaft 11 described above is connected to the sun gear 13 of the planetary gear mechanism 12 so as to be capable of transmission. In addition to the sun gear 13 described above, the planetary gear mechanism 12 includes a planetary gear 14 that meshes with the sun gear 13, a carrier 15 that supports the planetary gear 14, an internal gear 16 that meshes with the planetary gear 14, and a fixing ring 17. And has a deceleration function as is well known, and the deceleration output is output from the carrier 15.
[0016]
As shown also in FIG. 2, the locking device 20 for locking the output shaft 10 includes the carrier 15 described above, a lock ring 21 opposed to the carrier 15 in the axial direction, and two circles that hold the carrier from both sides. The plate-shaped holding plate 22 and the above-described internal gear 16 that locks the rotation of the lock ring 21 are configured.
[0017]
As shown in FIG. 3, the shaft core portion of the carrier 15 and the inner end portion of the output shaft 10 are connected to each other so as to be able to transmit with each other, and this fitting structure is connected to the inner end of the output shaft 10. In a predetermined range in the axial direction, the two peripheral surfaces facing each other across the axis are formed in a plane to form the connection fitting portion 23, and the connection fitting portion 24 of the carrier 15 to be fitted thereto is formed. Forms a play angle in which transmission is not performed by a predetermined angle θ in the forward and reverse rotation directions from the neutral position.
[0018]
In FIG. 2, the central portion of the two holding plates 22, 22 described above has a connection fitting portion 29 (see FIG. 6) that fits into the connection fitting portion 23 of the output shaft 10 without play. And rotate integrally with the output shaft 10.
When the carrier 15 is the driving side, the output shaft 10 can be referred to as the driven side, and the holding plates 22 and 22 are driven side outputs that face the driving side carrier 15 in the axial direction. It is fixed to the inner end side of the shaft 10.
[0019]
Further, as shown in FIG. 3, the inner side surface of the carrier 15 has the same inclined inner wall surface at a position facing the shaft core in order to release the lock state of the lock ring 21. The cam holes 28, 28 directed in the direction are formed, and pins 27, 27 of a lock ring 21 (to be described later) are inserted into the cam holes 28, 28, and when the carrier 15 rotates in the driving direction, the cam hole 28 , 28 contact the pins 27, 27 and move them from the lock position side of the lock ring 21 to the lock release position side.
[0020]
As shown in FIG. 4, five lock claws 25 are formed on two outer peripheral portions facing each other across the axis of the lock ring 21 described above, and the inner positions of the respective lock claws 25. The above-described pins 27, 27 are implanted and fixed in the middle part of the five lock claws 25, and one end thereof extends to the cam holes 28, 28 of the carrier 15.
[0021]
When the above-described lock ring 21 is eccentrically moved to the lock position side set on the outer side in the radial direction on one side of the lock claw 25... (For example, the upper side in the figure), the lock claw 25. It is provided so as to be able 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 null gear 16.
[0022]
The gear 26 of the internal gear 16 is normally formed in the shape of an internal gear, but the lock pawls 25 of the lock ring 21 are formed in a shape that meshes with the gear 26 described above. When the five lock claws 25 are meshed with each other, the five sheets are meshed with equal contact, and the rotational load at the time of locking can be equally received by the five lock claws 25. Get.
[0023]
When the lock claws 25 are formed as external gears, one of the five lock claws 25 is in strong contact with one gear 26 of the internal gear 16 and receives a concentrated rotational load. The strength of the gear 26 and the lock claws 25 is more required.
[0024]
Further, the fact that the lock claws 25 are formed at two opposite positions of the lock ring 21 is that when the lock ring 21 is rotated, the center portion is shifted to the unlock position by the centripetal movement. In the case of assembling, the direction of the lock ring 21 is allowed in two directions to facilitate the assembly, and even if a problem occurs in the lock claw 25 on one side, the lock claw 25 on the opposite side This is to enable use.
[0025]
FIG. 6 shows the above-described holding plates 22 and 22, and the two holding plates 22 have the same structure, and therefore one of them is shown.
The above-mentioned holding plate 22 forms a coupling fitting portion 29 that fits with the coupling fitting portion 23 of the output shaft 10 without play and rotates integrally with the shaft core portion. In the position facing 27, long holes 30 and 30 for guiding the sliding of the pins 27 and 27 in and out in the radial direction are formed.
[0026]
Therefore, the pins 27 and 27 of the lock ring 21 are inserted into the elongated holes 30 and 30 of the two holding plates 22 and 22 from the left and right, and the lock ring 21 is located on the radially outer lock position and on the inner side (axial side). It is slidably held in the unlocked position.
Note that the holding plate 22 can hold the lock ring 21 by one of the left and right ones.
[0027]
As shown in FIG. 7, the lock claw 25 on one side (lock side) of the lock ring 21 is provided between the inner peripheral portion of the lock ring 21 and the plane portion of the coupling fitting portion 23 of the output shaft 10. Is interposed with a spring member 31 formed in the shape of a cow horn that urges...
[0028]
As shown in FIGS. 1, 2, and 8, in the planetary gear mechanism 12 described above, the internal gear 16 is supported so as to be free to rotate with respect to the fixing ring 17, and the outer end of the internal gear 16 has an uneven surface. The torque limiter is configured by forming the ball 40 and pressing the ball 41 against it to press the internal gear 16 toward the fixed plate 42 to restrict its rotation.
[0029]
A plurality of (for example, six) balls 41 are in contact with each other, the fixing member 43 is in contact with the outer end of the internal gear 16, and the fixing member 43 is opposed to the internal gear 16. On the other side, a storage hole 39 is formed at a position corresponding to the above-described ball 41 to store a spring 44 for pressing the above-mentioned ball 41, and the outer end of this spring 44 is a support for the receiving member 45. A pin 46 is inserted and held.
[0030]
A screw 47 by a square screw is formed on the outer peripheral portion of the fixing member 43 described above, and a nut member 48 is screwed to the screw 47, and the advancement / retraction of the nut member 48 is performed via the ball 49 and the ring 50 as described above. By moving the receiving member 45 in the axial direction and adjusting the elasticity of the spring 44, the torque of the torque limiter by the above-described ball 41 and the uneven surface 40 of the internal gear 16 can be adjusted.
[0031]
The 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 turning, the nut member 48 can be turned. Further, the fixing plate 42, the fixing ring 17 and the fixing member 43 are integrally connected by an appropriate connecting mechanism to be fixed.
[0032]
Operation | movement of the locking device 20 of the output shaft 10 comprised as mentioned above is demonstrated.
1, 7, and 9, the motor shaft 11 is stopped, and the positions of the pins 27 and 27 of the lock ring 21 and the cam holes 28 and 28 of the carrier 15 are the center of the cam hole 28 shown in FIG. 3. Since the pin 27 is located at the upper position, the lock ring 21 is urged outward in the radial direction by the spring member 31, so that the gear 25 on the lock side of the lock ring 21 is controlled to rotate internally. It meshes with the gear 26 of the gear 16 and is in the locked state shown in FIG.
[0033]
In this state, for example, when a forward or reverse rotation is manually applied from the output shaft 10 side, the rotation does not rotate because the carrier 15 has a play angle θ. Since there is no play angle θ with the plate 22, the holding plate 22 receives the rotational force of the output shaft 10, and the lock plate 21 is connected to the lock ring 21 through the long hole 30 of the hold plate 22 and the pin 27 of the lock ring 21. Transmission power is transmitted.
[0034]
However, since 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 by the elasticity of the spring 44 as described above, it is not rotated. . Therefore, the output shaft 10 is in a locked state and is prevented from being manually rotated.
[0035]
Since the rotation load applied to the lock claw 25 described above is in the circumferential direction and the meshing direction of the lock claw 25 is the radial direction, the lock claw 25 is detached from the gear 26 or bites into the gear 26 due to the rotation load. It will not be impossible to leave.
[0036]
When the manual rotation of the output shaft 10 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.
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.
[0037]
As described above, when driving the output shaft 10 in the locked state, if the motor is driven in this locked state and the motor shaft 11 is rotated in a predetermined driving direction, the above-described locked state is automatically set. Canceled.
[0038]
As shown in FIGS. 10 and 11, the rotation of the motor shaft 11 described above is decelerated by the planetary gear mechanism 12 and output from the carrier 15, but the coupling fitting portion 23 between the carrier 15 and the output shaft 10, 24 has a play angle θ, so that the turning force is transmitted to the output shaft 10 after the carrier 15 is rotated by the play angle θ.
[0039]
While the carrier 15 is rotated by the play angle θ, the inclined inner wall surfaces of the cam holes 28, 28 of the carrier 15 operate and shift the pins 27, 27 of the lock ring 21 to the lock release position side in the radial direction. . Due to the action of the cam holes 28, the lock ring 21 moves to the unlocking position on the shaft core side against the spring member 31, and the lock claw 25 comes off the gear 26 of the internal gear 16 and rotates the output shaft 10. Movement is allowed.
[0040]
In this case, when a rotational force is transmitted to the lock ring 21 (transmission from the holding plate 22 side), the lock ring 21 is formed in a ring having a substantially uniform circumference, so that the centripetal force acts by the rotation. Then, it rotates at a position concentric with the output shaft 10, and the outer locking claw 25 does not engage with the gear 26 of the internal gear 17.
[0041]
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. When an overload acts on the output shaft 10 under the drive state of the output shaft 10 and the load 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.
[0042]
Next, when the motor in the driving state is stopped and the rotation of the motor shaft 11 is stopped, the torque on the motor shaft 11 decreases, and the inertia on the output shaft 10 side becomes large (stop of the motor shaft 11). Therefore, the rotation of the output shaft 10 precedes the carrier 15, and the mutual play angle θ reverses by this rotation, and the pins 27 of the lock ring 21 by the cam holes 28, 28 of the carrier 15 27 is released, the pins 27 and 27 are returned to the neutral position by the centrifugal force and the biasing force of the spring member 31, and the lock ring 21 moves 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, and is locked.
[0043]
Therefore, when the motor shaft 11 stops, the output shaft 10 stops rotating immediately, and there is no rotation due to inertia, thereby improving safety.
When the output shaft 10 stops without generating inertia, the output shaft 10 can be manually rotated in the direction of inertia to obtain the locking action as described above. Further, when the rotation due to the inertia of the output shaft 10 exceeds the elastic force by the spring 44, the internal gear 16 rotates against the pressing of the spring 44, and the torque limiter functions.
[0044]
In the above-described embodiment, when the concave / convex surface 40 of the inner end face of the internal gear 16 is formed into a flat surface and the ball 41 is changed to a brake pad, a brake mechanism can be configured in this portion, and the above-described torque limiter is replaced with the brake mechanism Can be configured.
[0045]
12 to 15 show other examples of the lock ring 21 described above. In FIG. 12, in this example, two lock plates 21a and 21a divided in the radial direction (two in the circumferential direction) are provided. And two springs 31a, 31a for urging these lock plates 21a, 21a to the opposite lock positions in the radial direction, and three on the outer periphery of each of the lock plates 21a, 21a. Are formed, and pins 27 are planted on the side surfaces. The pin 27 operates in the same manner as the embodiment shown in FIG.
[0046]
As shown in FIGS. 14 and 15, the internal gear 16a located on the outer periphery of the lock plates 21a and 21a is formed separately from the internal gear 16 shown in the embodiment shown in FIG. In this example, the internal gear 16 is fixed to the corresponding position. The gears 26 of the internal gear 16a mesh with the lock claws 25 of the lock plates 21a and 21a. The gear 26 and the lock claw 25 are formed under the same conditions as those of the first embodiment already described.
[0047]
As shown in FIG. 13, the cam holes 28 and 28 formed at the corresponding positions of the carrier 15 facing the pins 27 and 27 of the two lock plates 21a and 21a described above are positions facing each other across the shaft core. The cam holes 28 are formed in a substantially triangular shape having an inclined inner wall surface with respect to the outer side in the radial direction.
[0048]
As shown in FIG. 14, the lock plates 21a and 21a configured as described above are engaged with the gears 26 of the internal gear 16a by the urging force of the springs 31a and 31a, so that the output shaft 10 (see FIG. 1) is engaged. Lock it.
[0049]
When the motor shaft 11 (see FIG. 1) is driven, the pins 27 and 27 are pushed radially inward by the inclined inner wall surfaces of the cam holes 28 and 28 while the carrier 15 is rotated by the initial play θ. As shown in FIG. 15, the lock claws 25 of the lock plates 21a, 21a are disengaged from the gear 26 of the internal gear 16a, the lock is released, and the rotation of the motor shaft (see FIG. 1) is allowed. The
[0050]
According to the configuration of the lock plates 21a and 21a described above, since the lock is performed at two places, the lock having higher strength than the lock ring 21 shown in FIG.
Note that a plurality of lock plates 21a other than two may be provided, and the lock strength can be further increased.
[0051]
In the 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 correspond to the motor shaft 11 and the output shaft 10 of the embodiment,
Similarly,
The connecting portion corresponds to the coupling fitting portions 23 and 24 between the output shaft 10 and the carrier 15,
The locking mechanism corresponds to the locking device 20,
The lock member corresponds to the lock ring 21 and the lock plate 21a,
The fixing member forming the engaging claw corresponds to the internal gears 16 and 16a forming the gear 26,
The lock operating member corresponds to the carrier 15 in which the cam hole 28 is formed,
The configuration of the cam surface on one side and the pin on the other corresponds to the configuration of the pin 27 and the cam hole 28.
The present invention is not limited to the configuration of the above-described embodiment, but is applied based on the technical idea of the invention.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of an output shaft locking device.
FIG. 2 is a partially exploded view of a locking device portion.
FIG. 3 is a front view of a carrier.
FIG. 4 is a front view of a lock ring.
FIG. 5 is a front view of an internal gear.
FIG. 6 is a front view of a holding plate.
FIG. 7 is a front view showing a locked state of the locking device.
FIG. 8 is an exploded view of a torque limiter mechanism portion.
FIG. 9 is a cross-sectional view showing a locked state of the locking device.
FIG. 10 is a front view showing an unlocked state of the locking device.
FIG. 11 is a cross-sectional view showing an unlocked state of the locking device.
FIG. 12 is an exploded view of a lock plate of another example of the locking device.
FIG. 13 is a front view of a carrier.
FIG. 14 is a front view showing a locked state of the locking device.
FIG. 15 is a front view showing an unlocked state of the locking device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Output shaft 12 ... Planetary gear mechanism 15 ... Carrier 16, 16a ... Internal gear 17 ... Fixing ring 20 ... Locking device 21 ... Lock ring 21a ... Lock plate 22 ... Holding plate 23, 24 ... Connection fitting part 25 ... Lock Claw 26 ... Gear 27 ... Pin 28 ... Cam hole 40 ... Rough surface 41 ... Ball 44 ... Spring

Claims (5)

The output shaft is formed by connecting the drive shaft and the driven shaft,
In the connecting portion connecting the drive shaft and the driven shaft, a play angle is formed in which power is not transmitted by a predetermined angle in the mutual rotation direction,
Provided on the driven shaft side is a lock mechanism that locks the lock member that is held by the driven shaft so as to be movable inward and outward in the radial direction by moving to a fixed member provided on the outer periphery thereof.
On the drive shaft side facing the lock member in the axial direction, the lock member is moved to the unlocking position while the play angle of the connecting portion disappears by the initial rotation of the drive shaft, and the drive is driven. An output shaft locking device provided with a lock operating member for operating movement of the lock member to the lock position while rotating the driven shaft by the free angle of the connecting portion when the rotation of the shaft is stopped. Forming a lock claw on the lock member, forming an engagement claw to engage with and disengage from the lock claw on the fixed member, and forming the lock mechanism by engagement of the lock claw and the engagement claw;
Forming a pin on one of the lock member and the lock operating member and a cam surface on the other;
The cam surface is formed as a cam surface that abuts against the pin and moves the lock member to the unlocking position while the idle angle of the connecting portion is eliminated by the initial rotation of the drive shaft. The output shaft locking device described. The output shaft locking device according to claim 1 or 2, wherein a plurality of the locking members are arranged in a circumferential direction of the driven shaft to form a locking mechanism. The fixing member is formed in a ring shape and is rotatably held by the fixing portion,
4. The output shaft locking device according to claim 1, wherein the fixing member is pressed and fixed with a predetermined load to form a torque limiter. The fixing member is formed in a ring shape and is rotatably held by the fixing portion,
4. The output shaft locking device according to claim 1, wherein the fixing member is pressed and fixed with a predetermined load to form a brake.

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