JPH04372372A - Locking device of rotational tool - Google Patents

Abstract

PURPOSE:To carry out automatic locking and automatic releasing in a simple structure, to achieve noiseless function and high reliability, and to facilitate integration of a torque limiter. CONSTITUTION:Locking members 50a, 50b are arranged in a wedged space provided with surfaces, which are provided between the peripheral surface of an output shaft 7 and the inner circumferential surface of a lock ring 51, and which are tilted in the tangent direction and in the shaft direction, while locking of the output shaft is carried out by moving and the locking member opposed to the lock ring as well as the output shaft in the circumferential direction and whereby letting it bite in that direction. The output shaft is provided as a planetary carrier 34 of a planetary reduction gear, while a ring gear 33 whose rotation in a predetermined angle is to be freely carried out to a tool housing of the planetary reduction gear is provided with a protrusion 55 for release for pressing the locking member in the shaft direction and for thereby removing it from the biting position.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a locking device for a rotary tool such as an electric screwdriver or an electric wrench, and more particularly to a locking device for a rotary tool capable of automatically locking and automatically releasing an output shaft.

0002

[Prior Art] For rotary tools such as electric screwdrivers and electric wrenches, the ability to lock the rotation of the output shaft enables use as a hand-crank type, and tightening by hand or electric power is not possible. This is very useful because it allows you to perform auxiliary tightening by hand when it is not fully tightened. In order to provide this type of locking function, we have two methods: auto-release, which automatically releases the lock when the motor rotates while in the locked state, and auto-lock, which automatically locks when the motor is stopped. It is preferable from the viewpoint of usability that this is done.

[0003] Various types of devices equipped with such auto-lock and auto-release functions have been proposed in the past. There are those whose locking device is turned on and off in conjunction with the
As shown in Japanese Patent No. 5, there is a device that utilizes the movement of a ring gear of a planetary gear device to engage and close a locking device using a ratchet pawl.

0004

[Problem to be Solved by the Invention] However, in the former case, a locking device located at a distant place is remotely controlled by operating the switch handle, so there are restrictions on the placement position of the switch, and it is difficult to organize the switch in a compact manner. It has problems such as being difficult to use. In the latter case, there are problems in that the ratchet pawl makes an operating sound, that the strength of the member supporting the ratchet pawl is difficult to maintain, and that the shape of the member becomes complicated, resulting in increased costs.

[0005] The present invention has been made in view of the above points, and its purpose is to perform auto-lock and auto-release with a simple structure, be quiet and highly reliable, and furthermore, be able to use a torque limiter. To provide a rotary tool such as an electric screwdriver or an electric wrench that is easy to incorporate.

[0006]

[Means for Solving the Problems] The present invention provides a lock ring fixed to a tool housing, an output shaft disposed on the inner peripheral side of the lock ring, and a connection between the outer peripheral surface of the output shaft and the lock ring. A locking member formed of a ball disposed in a wedge-shaped space having a surface inclined both in the tangential direction and the axial direction provided between the locking member and the inner circumferential surface, the locking member for the locking ring and the output shaft. A rotary tool in which an output shaft is locked with respect to a housing by engagement of circumferential movement, and the output shaft is provided as a planet carrier of a planetary reduction device, and the output shaft is provided at a predetermined position with respect to the tool housing in the planetary reduction device. The first feature of the ring gear, which can freely rotate within an angle, is that it is equipped with a release protrusion that presses the lock member in the axial direction to remove it from the engagement position. A lock ring whose rotation is regulated and is slidable in the axial direction, an output shaft arranged on the inner circumferential side of the lock ring, and a space between the outer circumferential surface of the output shaft and the inner circumferential surface of the lock ring. A locking member consisting of a ball or roller disposed in a wedge-shaped space having surfaces inclined both in the tangential direction and the axial direction is provided to prevent circumferential movement of the locking member relative to the lock ring and the output shaft. The rotary tool includes an output shaft that is locked to the housing, and the output shaft is provided as a planet carrier of a planetary reduction device, and the output shaft is rotated within a predetermined angle with respect to the tool housing in the planetary reduction device. Another feature of the rotatable ring gear is that it includes a release protrusion that presses the lock ring in the axial direction to release the lock by the lock member.

According to the present invention, the output shaft is automatically locked by the locking member biting into the wedge-shaped space formed between the outer peripheral surface of the output shaft and the inner peripheral surface of the lock ring, When the motor is rotated to drive the output shaft, auto-release is performed because the ring gear's release protrusion presses the lock member or lock ring in the axial direction during the initial rotation of the ring gear. be.

[0008]

[Embodiment] The present invention will be described in detail below based on the illustrated embodiment. A sun gear 31 fixed to the output shaft 20 of the motor 2
, a ring gear 33 rotatably disposed within the gear case 6 , a plurality of planetary gears 32 meshing with both of the ring gears 33 , and a carrier 34 having a shaft 35 that supports each planetary gear 32 . is provided as a deceleration means, and a chuck 8 is attached to the carrier 34 in this planetary mechanism.
An output shaft 7 is integrally formed. In the figure, 60 is a motor mounting base, 61 is a sliding bearing that receives the output shaft 7, and 6
2 is a thrust plate, 63 is a retaining ring, 64, 65, 66 are steel balls and a retainer constituting a thrust bearing, and 67 is a thrust plate.

A lock ring 51 fixed to the housing 10 via the gear case 6 is disposed on the outer peripheral surface of the portion of the output shaft 7 on the ring gear 33 side. This lock ring 51 is provided with a plurality of recesses 52 on its inner circumferential surface, each having a surface inclined with respect to both the tangential direction and the axial direction. The recesses 52, 52 are provided on both sides of the partitioning piece 57, and the directions of inclination with respect to the tangential direction are opposite on both sides. A ball-shaped locking member 5 is inserted into two types of wedge-shaped spaces having different directions in the tangential direction between the output shaft 7 outer peripheral surface and these recesses 52.
0a and 50b, respectively, and these locking members 50a and 50b are urged by a spring member 58 toward the ring gear 33, that is, toward the narrower side of the wedge-shaped space in the axial direction. The locking member 50a is for locking rotation in one direction, and the locking member 50b is for locking rotation in the other direction. When it moves, it is in a floating state, but when it is on the ring gear 33 side and away from the partition piece 57 due to the biasing force of the spring member 58, it is caught between the outer circumferential surface of the output shaft 7 and the inner circumferential surface of the lock ring 51. to lock the output shaft 7 to the housing 10.

On the other hand, a release protrusion 55 is provided on the inner circumferential side of the tip end surface of the ring gear 33, and a clutch protrusion 77 is provided on the outer circumferential side. The clutch protrusion 77 here is engaged with a clutch handle 70 rotatably disposed on the outer periphery of the tip of the gear case 6, a stepped protrusion 71 formed on the inner peripheral surface of the clutch handle 70, and the stepped protrusion 71. clutch plate 72, clutch plate 7
Clutch spring 73 with one end in contact with 2, clutch spring 73
The ring gear 33 is caused to idle when the load torque exceeds a predetermined value by the thrust plate 74 that the other end contacts, and the ball 75 that is disposed in a through hole formed in the gear case 6 and contacts the thrust plate 74. By doing so, it constitutes a torque limiter that makes the output shaft 7 free.

Next, the operation will be explained. Now motor 2
When the output shaft 7 is rotated clockwise and the output shaft 7 is rotated in the direction of the arrow in FIG. The locking member 50b is rotated in the opposite direction until the rotation is blocked, and the locking member 50b is moved in the axial direction by the release protrusion 55, as shown in FIGS. 4 to 6, to place the locking member 50b in the floating position. Further, the locking member 50a is sent into the partitioning piece 57 side of the wedge-shaped space by the rotation of the rotating shaft 7. As a result, the locking members 50a, 50b do not hinder the rotation of the output shaft 7. When the motor 2 is rotated in the opposite direction, the locking member 50a is moved against the spring member 58, and the locking member 50b moves toward the partition piece 57 as the output shaft 7 rotates. 7
rotation is not obstructed. In particular, here, the distal end surface of the release protrusion 55 is an inclined surface, and the lock members 50a,
Since the lock members 50b are lifted from the outer circumferential surface of the output shaft 7, no noise or load is generated by the lock members 50a, 50b. Also,
When the motor 2 is being driven and its load torque exceeds the value set by the torque limiter, the ring gear 33
Since the ball 75 begins to idle while pushing out the ball 75, no output is transmitted to the output shaft 7.

[0012] Then, with the motor 2 stopped rotating,
If the housing 10 is rotated in the tightening direction around the axis of the output shaft 7 to perform manual tightening, that is, if the output shaft 7 is rotated in the direction shown by the arrow in FIG. 5 relative to the lock ring 51. For example, the locking member 51b separates from the partition piece 57 due to rolling due to friction between the locking member 51b and the output shaft 7, moves to the narrow side of the wedge-shaped space, and locks the lock ring 51 and the output shaft 7.
The rotation of the output shaft 7 relative to the housing 10 is immediately locked. When the housing 10 is rotated in the opposite direction, the locking member 50a performs locking. still,
The positional relationship between the two protrusions 55 and 77 is set so that when the clutch protrusion 77 comes into engagement contact with the ball 75, the release protrusion 55 presses the locking member 50a. In addition, the ring gear 33 also tries to rotate due to the relative rotation between the housing 10 and the output shaft 7, but in reality it hardly follows the minute rotation of the output shaft 7 due to the backlash and play of the gear. In addition, since the lock members 50a and 50b do not move in the direction of releasing the lock, the lock is reliably locked. However, depending on the initial position of the release protrusion 55 of the ring gear 33, the locking members 50a and 50b may not move smoothly to the engagement position. Just rotate it in the opposite direction. Considering the way the tool is used, this should not be a problem.

In the embodiment shown in FIG. 7, the axially inclined surface in the wedge-shaped space is formed not on the lock ring 51 but on the outer peripheral surface of the output shaft 7. In this case, the operation is actually exactly the same as in the above embodiment. Other embodiments are shown in FIGS. 8 to 12. The lock ring 51 here is rotationally restricted with respect to the gear case 6, is slidable in the axial direction, and is biased toward the ring gear 33 by a spring member 58, and has a surface on the ring gear 33 side. The spring member 5 is engaged with the release protrusion 55 of the ring gear 33.
An engaging protrusion 59 is formed to move the lock ring 51 forward against the lock ring 8. A wedge-shaped space having a surface inclined in the tangential direction and the axial direction is formed between the recess 52 on the inner circumferential surface of the lock ring 51 and the tapered portion on the outer circumferential surface of the output shaft 7.
a and 50b are arranged. In this device, the lock is released by moving the lock ring 51 in the axial direction rather than by moving the lock members 50a and 50b, and the operation is the same as in the previous embodiment except for this point. can get.

FIG. 13 shows the external appearance of a rotary tool equipped with such a circumferential locking and axially releasing locking device. In the figure, 1 is the main body, 9 is a bit attached to the chuck 8, and 11 is a switch. A handle, 12 is a rotation direction switching handle, and 13 is a power pack.

[0015]

As described above, in the present invention, the output shaft is automatically locked by the locking member biting into the wedge-shaped space formed between the outer peripheral surface of the output shaft and the inner peripheral surface of the lock ring. When the motor is rotated to drive the output shaft, the initial rotation of the ring gear causes the release protrusion of the ring gear to press the lock member or lock ring in the axial direction, releasing the lock. It has an auto-release function to perform the operation, and is very easy to use as a rotating tool such as an electric screwdriver or an electric wrench. Moreover, each of these parts may have a simple shape and is highly reliable. be. Furthermore, since the lock is released as described above, a ring gear that forms part of the torque limiter can be used as the ring gear.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of one embodiment when locked.

FIG. 2 is a cross-sectional view when locked.

FIG. 3(a) is a cross-sectional view of the torque limiter portion when locked, and FIG. 3(b) is a cross-sectional view of the unlocking portion when locked.

FIG. 4 is a longitudinal cross-sectional view when the lock is released.

FIG. 5 is a cross-sectional view when the lock is released.

FIG. 6(a) is a cross-sectional view of the torque limiter portion when the lock is released, and FIG. 6(b) is a cross-sectional view of the lock release portion when the lock is released.

FIG. 7 is a longitudinal cross-sectional view of a lock portion of another embodiment.

FIG. 8 is a longitudinal cross-sectional view of another embodiment when locked.

FIG. 9 is a cross-sectional view when locked.

FIG. 10 is a vertical cross-sectional view when the lock is released.

FIG. 11 is a cross-sectional view when the lock is released.

FIG. 12(a) is a cross-sectional view of the torque limiter portion when the lock is released, and FIG. 12(b) is a cross-sectional view of the lock release portion when the lock is released.

FIG. 13 is a side view of the exterior.

[Explanation of symbols]

7 Output shaft 33 Ring gear 34 is career 50a, 50b Lock member 51 Lock ring 52 Recess 55 Release protrusion

Claims (4)

[Claims] [Claim 1] A lock ring fixed to the tool housing, an output shaft disposed on the inner peripheral side of the lock ring, and a lock ring provided between the outer peripheral surface of the output shaft and the inner peripheral surface of the lock ring. A locking member consisting of a ball disposed in a wedge-shaped space having surfaces inclined both in the tangential direction and the axial direction, and the output to the housing is generated by the engagement of the locking member with respect to the lock ring and the output shaft in the circumferential direction. The shaft is locked, and the output shaft is provided as a planet carrier of the planetary reduction device, and the ring gear is rotatable within a predetermined angle with respect to the tool housing in the planetary reduction device. A locking device for a rotary tool, characterized in that it is provided with a release protrusion that presses the locking member in the axial direction to remove it from the engaged position. 2. The locking device for a rotary tool according to claim 1, wherein the distal end of the releasing projection has an inclined surface that lifts the locking member from the outer peripheral surface of the output shaft. [Claim 3] A lock ring whose rotation is restricted relative to the tool housing and which is slidable in the axial direction, an output shaft disposed on the inner peripheral side of the lock ring, an outer peripheral surface of the output shaft, and the lock ring. a locking member consisting of a ball or a roller disposed in a wedge-shaped space having a surface inclined both in the tangential direction and the axial direction and provided between the inner circumferential surface of the locking ring and the output shaft; The output shaft is locked with respect to the housing by the circumferential movement of the locking member. 1. A locking device for a rotary tool, wherein the ring gear, which is rotatable within a predetermined angle, is provided with a release protrusion that presses the lock ring in the axial direction to release the lock by the lock member. 4. The rotation range of the ring gear is restricted by a torque limiter formed by a clutch protrusion provided on the ring gear and a clutch member that is spring-biased and engaged with the clutch protrusion. Claim 1
Or a locking device for a rotating tool according to claim 3.