JPH0777708B2 - Rotating tool locking device - Google Patents

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art In a rotary tool such as an electric screwdriver or an electric wrench, locking the rotation of the output shaft makes it possible to use it as a hand-operated type, and it is not possible to tighten it by the feeling of the hand or to use electric power. It is very useful because it can be tightened by hand when auxiliary tightening is not possible. In order to provide such a lock function, there are an auto-release function that automatically releases the lock when the motor is rotated in the locked state, and an auto-lock function that automatically locks the motor when the motor is stopped. It is preferable in terms of usability to be prepared.

Various types of devices having such auto-locking and auto-releasing functions have been proposed in the past. For example, as shown in Japanese Patent Laid-Open No. 62-287979, the switch operation is performed. The one that the lock device is turned on and off in conjunction with, and Japanese Patent Publication No. 63-1759.
As disclosed in Japanese Patent Laid-Open No. 5 (1994), there is a device that utilizes the movement of a ring gear of a planetary gear device to open and close a locking device by a ratchet pawl.

[0004]

However, in the former case, since the lock device located at a distant place is remotely operated by operating the switch handle, the position where the switch is arranged is restricted or the switch is arranged compactly. It has problems such as difficulty. In the latter case, there is a problem that operating noise of the ratchet pawl is generated, the strength of a member supporting the ratchet pawl is difficult, and the shape of the member is inevitably complicated, resulting in cost increase. Tokusho
No. 59-44192 discloses a device having a rice ball-shaped cross section.
The wedge-shaped space formed between the force axis and the surrounding members is locked.
The output shaft of the planetary speed reducer is
The above is attached to the planet carrier connected with play in the enclosure.
A member that controls the position of the lock member is formed to
And the ones for automatic release are shown.
However, the lock structure in this one has a wedge-shaped space.
In order to move with the rotation of the output shaft, that is, the lock part
Because the material rotates with the output shaft, load fluctuations during rotation are prevented.
The rotation inertia causes the lock member to move to the narrow side of the wedge-shaped space.
Then apply sudden braking or lock the output shaft.
However, there is a problem in terms of reliability.

The present invention has been made in view of the above points, and an object of the present invention is to perform auto-locking and auto-releasing with a simple structure, which is quiet and highly reliable. It is to provide a rotary tool such as an electric screwdriver or an electric wrench that is easy to install.

[0006]

SUMMARY OF THE INVENTION The present invention, however, is fixed to the tool housing and has a small depth.
Has a concave portion that changes at least in the circumferential direction on the inner peripheral surface
And a lock ring has an output shaft disposed in the lock ring inner circumference side, the recess of the output shaft outer circumferential surface and the locking ring
Surrounded by and with circumferential and axial shapes
There a lock member made of balls are arranged in wedge-shaped spaces that are both wedge-shaped, Engineering in biting by circumferential movement of the locking member relative to the locking ring and the output shaft
Be one locking of the output shaft relative to jig the housing is made, the output shaft is provided as a planetary carrier of a planetary reduction gear, the rotation of a predetermined angle with respect to the tool housing in the planetary reduction gear is freely Ring gear
However , it has a first feature in that it is provided with a release projection for pushing the lock member in the axial direction of the output shaft to disengage it from the engaged position, and is also restricted in rotation with respect to the tool housing. Along with the lock ring that is slidable in the axial direction, the inner peripheral surface has a depth of at least the peripheral direction.
There an output shaft disposed in <br/> inner periphery of the locking ring has a recess that changes, the circumferential shape with enclosed by and the recess of the output shaft outer circumferential surface and the locking ring
A lock member composed of a ball and a roller arranged in a wedge-shaped space that is wedge-shaped and inclined in the axial direction is provided, and output to the tool housing is obtained by biting by the circumferential movement of the lock member with respect to the lock ring and the output shaft. be one locking shaft is made, the output shaft is provided as a planetary carrier of a planetary reduction gear, a ring gear rotation is freely within a predetermined angle relative to the tool housing in the planetary reduction gear device, Another feature is that the lock ring is provided with a release projection for axially pressing the lock ring to release the lock.

According to the present invention, the lock shaft is engaged with the wedge-shaped space formed between the outer peripheral surface of the output shaft and the inner peripheral surface of the lock ring to automatically lock the output shaft. When the output shaft is driven by rotating the motor, the initial release of the ring gear causes the release projection of the ring gear to press the lock member or lock ring in the axial direction, so that automatic release is performed. is there.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the illustrated embodiments. A sun gear 31 fixed to an output shaft 20 of a motor 2
And a carrier 34 having a ring gear 33 rotatably arranged in the gear case 6, a plurality of planet gears 32 meshing with the ring gear 33, and a carrier 34 having a shaft 35 for supporting each planet gear 32. Are provided as deceleration means, and the chuck 8 is attached to the carrier 34 in this planetary mechanism.
The output shaft 7 provided with is integrally formed. In the figure, 60 is a motor mount, 61 is a sliding bearing for receiving the output shaft 7, 6
Reference numeral 2 is a thrust plate, 63 is a retaining ring, 64, 65 and 66 are steel balls and retainers constituting a thrust bearing, and 67 is a thrust plate.

A lock ring 51 fixed to the housing 10 via a gear case 6 is disposed on the outer peripheral surface of the output shaft 7 on the ring gear 33 side. The lock ring 51 has a depth on the inner peripheral surface in the circumferential direction and the axial direction.
And a plurality of recesses 52 that are gradually changing .
The recesses 52, 52 are provided on both sides of the partition 57, and in the circumferential direction on both sides .
The direction of depth change (the direction of inclination with respect to the tangential direction) is opposite. The outer peripheral surface of the output shaft 7 and these recesses 52
A ball-shaped locking member 50 is provided in two wedge-shaped spaces between
The lock members 50a and 50b are respectively urged toward the ring gear 33 side by the spring member 58, that is, toward the narrow axial direction in the wedge-shaped space. The lock member 50a is for one-direction rotation lock, the lock member 50b is for the other-direction rotation lock, and the lock members 50a and 50b are the partition pieces 5.
Although it is in a floating state when it is positioned on the 7 side or moved forward against the spring member 58, when the spring member 58 urges it to the ring gear 33 side and away from the partition 57, the output is generated. The output shaft 7 is locked to the housing 10 by being caught between the outer peripheral surface of the shaft 7 and the inner peripheral surface of the lock ring 51.

On the other hand, a release projection 55 is provided on the inner peripheral side of the tip end surface of the ring gear 33, and a clutch projection 77 is provided on the outer peripheral side. The clutch projection 77 here is a clutch handle 70 rotatably disposed on the outer periphery of the tip of the gear case 6, a step-like projection 71 formed on the inner circumferential surface of the clutch handle 70, and the step-like projection 71. Clutch plate 72, clutch plate 7
Clutch spring 73, one end of which is in contact with 2, clutch spring 73
When the load torque exceeds a predetermined value, the ring gear 33 idles by means of a thrust plate 74 with which the other end of the ring contacts and a ball 75 arranged in a through hole formed in the gear case 6 and in contact with the thrust plate 74. By doing so, a torque limiter that makes the output shaft 7 free is configured.

Next, the operation will be described. Now motor 2
2 is rotated clockwise to rotate the output shaft 7 in the direction of the arrow in FIG. 2, the ring gear 33 is engaged with the clutch projection 77 and the ball 75 in the torque limiter due to the characteristics of the planetary speed reducer. It rotates in the opposite direction until its rotation is hindered, and as shown in FIGS. 4 to 6, the release projection 55 moves the lock member 50b in the axial direction to place the lock member 50b in the idle position. Also, the lock member 50a
Is sent to the partition 57 side of the wedge-shaped space by the rotation of the output shaft 7. As a result, the lock members 50a, 50b
Does not hinder the rotation of the output shaft 7. When the motor 2 is rotated in the reverse direction, the lock member 50a is moved against the spring member 58, and the lock member 50b moves toward the partition 57 side as the output shaft 7 rotates. The rotation of 7 is not hindered. Particularly, here, the tip end surface of the release projection 55 is an inclined surface, and the lock member 50 is
Since the a and 50b are floated from the outer peripheral surface of the output shaft 7, the rocking noises and loads of the lock members 50a and 50b are not generated. When the load torque of the motor 2 exceeds the value set by the torque limiter while the motor 2 is driven, the ring gear 33 pushes the ball 75 and starts idling.
Output is not transmitted to the output shaft 7.

Then, with the rotation of the motor 2 stopped,
In order to perform manual tightening, the housing 10 is tightened around the output shaft 7 in the tightening direction ( direction shown by an arrow in FIG. 5).
) Once rotated, the locking member 50b in rolling by friction between the output shaft 7 away from the compartment piece 57, moved towards a narrow wedge-shaped space, between the locking ring 51 and the output shaft 7 Engage and immediately lock rotation of output shaft 7 relative to housing 10. When the housing 10 is turned in the opposite direction, the lock member 50a locks. It should be noted that both projections 5 are arranged so that the release projection 55 presses the lock member 50a when the clutch projection 77 comes into engagement contact with the ball 75.
The positional relationship of 5,77 is set. Housing 1
By the relative rotation between 0 and the output shaft 7, the ring gear 3
3 also tries to rotate, but in reality, due to the backlash and backlash of the gear, it hardly follows the minute rotation of the output shaft 7, and therefore does not move in the direction to unlock the lock members 50a and 50b. , So it is definitely locked.
However, depending on the initial position of the release protrusion 55 of the ring gear 33, the lock members 50a and 50b may not move smoothly to the engaged position. Rotate in the opposite direction. This does not pose a problem in view of the tool usage.

In the embodiment shown in FIG. 7, the surface inclined in the axial direction 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 exactly the same as that of the above embodiment. 8 to 12 show another embodiment. The lock ring 51 here is regulated in rotation with respect to the gear case 6, is slidable in the axial direction, and is urged toward the ring gear 33 by a spring member 58. Is engaged with the release projection 55 of the ring gear 33, so that the spring member 5
An engagement projection 59 is formed which moves the lock ring 51 to the front side against 8. A wedge-shaped space having a surface inclined in the tangential direction and the axial direction is formed between the concave portion 52 on the inner peripheral surface of the lock ring 51 and the taper portion on the outer peripheral surface of the output shaft 7, and here, the roller-shaped lock member 50 is formed.
a and 50b are provided. In this case, the unlocking is performed by moving the lock ring 51 in the axial direction instead of moving the lock members 50a and 50b. Except for this point, the same operation as in the above embodiment is performed. can get.

FIG. 13 shows the appearance of a rotary tool equipped with such a locking device for circumferentially locking and axially releasing. In the figure, 1 is a main body, 9 is a bit mounted on a 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, according to the present invention, the lock member is engaged with the wedge-shaped space formed between the outer peripheral surface of the output shaft and the inner peripheral surface of the lock ring to automatically lock the output shaft. When the output shaft is driven by rotating the motor, the ring gear release protrusion pushes the lock member or lock ring in the axial direction by the initial rotation of the ring gear to release the lock. The automatic release is performed in order to perform the operation, and it is very easy to use as a rotating tool such as an electric screwdriver or an electric wrench, and the shape of each of these parts is simple, and ratchet noise is a problem. To do
Also, there is no recess on the inner surface of the lock ring.
Solution formed on the ring gear as well as forming a wedge-shaped space
In order to perform automatic release with the removal protrusion,
The locking member may lock the output shaft.
Moreover , reliable operation can be obtained and reliability is high. Furthermore, since the lock is released as described above, a ring gear that constitutes one member of the torque limiter can be used.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of an embodiment when locked.

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

3A is a sectional view of a torque limiter portion when locked, FIG. 3B is a sectional view of a lock release portion when locked, and FIG. 3C is a perspective view of a release protrusion .

FIG. 4 is a vertical cross-sectional view when unlocking.

FIG. 5 is a transverse cross-sectional view when unlocking.

6A is a cross-sectional view of a torque limiter portion when unlocking, and FIG. 6B is a cross-sectional view of the lock releasing portion when unlocking.

FIG. 7 is a vertical cross-sectional view of a lock portion according to another embodiment.

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

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

FIG. 10 is a vertical cross-sectional view when unlocking.

FIG. 11 is a cross-sectional view when unlocking.

12A is a cross-sectional view of a torque limiter portion when unlocking, and FIG. 12B is a cross-sectional view of the lock releasing portion when unlocking.

FIG. 13 is a side view of the appearance.

[Explanation of symbols]

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

Claims (4)

[Claims] 1. Fixed to a tool housing
And the depth changes at least in the circumferential direction.
A lock ring having a recess on the inner peripheral surface, an output shaft arranged on the inner peripheral side of the lock ring, an outer peripheral surface of the output shaft and the recess of the lock ring, and a circumferential direction.
A lock member composed of balls arranged in a wedge-shaped space having a wedge shape in both the shape and the axial shape, and the circumferential movement of the lock member with respect to the lock ring and the output shaft.
Be one locking of the output shaft is made with respect to the tool housing biting by, the output shaft is provided as a planetary carrier of a planetary reduction gear, the rotation of a predetermined angle with respect to the tool housing in the planetary reduction gear A rotary tool in which a ring gear which is freely provided is provided with a release projection for pressing the lock member in the axial direction of the output shaft to disengage it from the engaged position. 2. The lock device for a rotary tool according to claim 1, wherein the tip of the releasing projection has an inclined surface for floating the lock member from the outer peripheral surface of the output shaft. 3. A lock ring, which is rotationally restricted with respect to the tool housing and is slidable in the axial direction, and a depth on the inner circumferential surface which varies at least in the circumferential direction.
The output shaft arranged on the inner peripheral side of the lock ring having a recessed portion, and the outer peripheral surface of the output shaft and the upper part of the lock ring.
It is surrounded by the concave portion and has a wedge shape in the circumferential direction.
And a lock member composed of a ball and a roller arranged in a wedge-shaped space that is inclined in the axial direction, and moves in the circumferential direction of the lock member with respect to the lock ring and the output shaft.
Be one locking of the output shaft is made with respect to the tool housing biting by, the output shaft is provided as a planetary carrier of a planetary reduction gear, the rotation of a predetermined angle with respect to the tool housing in the planetary reduction gear A lock device for a rotary tool, wherein a freely rotatable ring gear is provided with a releasing projection for pressing the lock ring in the axial direction to release the lock. 4. The rotation range of the ring gear is regulated by a torque limiter that includes a clutch projection provided on the ring gear and a clutch member that is spring-biased and engaged with the clutch projection. The lock device for a rotary tool according to claim 1 or 3.