JPH06102305B2 - Rotary tool - Google Patents

Description

Description: 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 particularly to a rotary tool capable of automatically locking and releasing an output shaft.

[Conventional technology]

In a rotary tool such as an electric screwdriver or an electric wrench, enabling the output shaft to be locked allows it to be used as a hand-rolled type, and can be tightened by the feeling of the hand or when it cannot be tightened by electric force. This is very useful as it allows the auxiliary tightening to be done by hand. 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-lock and auto-release functions have been proposed in the past. For example, as disclosed in Japanese Patent Laid-Open No. 62-287979, they are linked with the switch operation. The lock device is turned on and off, and the lock device is turned on and off by the ratchet pawl by using the movement of the ring gear of the planetary gear device, as shown in JP-B-63-17595. .

[Problems to be Solved by the Invention]

However, the former has a problem in that the lock device located at a remote place is remotely operated by operating the switch handle, so that the position where the switch is arranged is restricted and it is difficult to compact the switch. .

In the latter case, ratchet pawl operating noise may occur,
There is a problem that the strength of the member that supports the ratchet pawl is difficult and the shape of the member is inevitably complicated, resulting in an increase in cost. In Japanese Patent Publication No. 59-44192, a lock member is arranged in a wedge-shaped space formed between an output shaft having a rice ball-shaped cross section and a member surrounding the output shaft, and the output shaft in a planetary reduction gear is provided with play within a predetermined range. It is shown that a planet carrier that is held and connected is formed with a member for restricting the position of the lock member so as to perform auto-lock and auto-release, but the lock structure in this is a wedge-shaped space. Because the motor moves with the rotation of the output shaft, that is, the lock member rotates with the output shaft, the load inertia during rotation causes the lock member to move toward the narrow side of the wedge-shaped space due to rotational inertia, and sudden braking is applied. There is a risk of locking the output shaft,
There is a problem in terms of reliability.

The present invention has been made in view of the above points, and an object thereof is to perform auto-locking and auto-releasing with a simple structure, and to provide a quiet and highly reliable rotation such as an electric screwdriver or an electric wrench. To provide tools.

[Means for Solving the Problems]

The present invention, therefore, has a lock ring fixed to the tool housing and having a recess on the inner peripheral surface whose depth changes in the circumferential direction, and a lock ring disposed on the inner peripheral side of the lock ring. An output shaft, and a lock member formed of a ball or a roller arranged in a wedge-shaped space surrounded by the outer peripheral surface of the output shaft and the recess of the lock ring, the output shaft being provided as a planet carrier of a planetary speed reducer. In addition, the release projection that pushes the lock member, which locks the output shaft with respect to the tool housing by the engagement with the lock ring and the output shaft, in the circumferential direction of the output shaft to release it from the engaged position, is provided in the planetary speed reducer. Its main feature is that it is provided on a ring gear that can freely rotate within a predetermined angle with respect to the tool housing.

[Operation] According to the present invention, the lock portion is engaged with the wedge-shaped space formed between the outer peripheral surface of the output shaft and the inner peripheral surface in which the recess of the non-rotatable lock ring is provided. When the motor is rotated and the output shaft is driven by automatic rotation, the ring gear release protrusion moves the lock member to the lock release position by the initial rotation of the ring gear. It is an auto-release.

[Embodiment] The present invention will be described in detail below with reference to the illustrated embodiment. A sun gear 31 fixed to the output shaft 20 of the motor 2 and a ring gear 33 rotatably arranged in the gear case 6. , A planetary mechanism consisting of a plurality of planetary gears 32 meshing with each other, and a carrier 34 having a shaft 35 for supporting each planetary gear 32 is provided as a deceleration means. An output shaft 7 provided with 8 is integrally formed. In the figure, 60 is a motor mount, 61 is a sliding bearing for receiving the output shaft 7, 62 is a thrust plate, 63 is a retaining ring, and 64,6.
Reference numerals 5 and 66 are steel balls and retainers that constitute the thrust bearing, and 67 is a thrust plate.

A lock ring 51 fixed to the housing 10 via the gear case 6 is arranged on the outer peripheral surface of the ring gear 33 side of the output shaft 7. The lock ring 51 has a concave portion 52 whose depth is gradually changed in the circumferential direction on the inner peripheral surface thereof.
And a groove whose one end is continuous with the shallower end of the recess 52.
53, two concave portions 52, 52 having different bottom slopes and different continuous directions of the groove 53 are provided sandwiching the partition piece 57, and the depth of the recessed portion 52 is provided on both sides of the partition piece 57. The deep place is located. Further, in the illustrated example, a set of two recesses
Two sets 52, 52 are provided, and a partition piece 58 is located between the groove 53 of one set and the groove 53 of the other set.

Then, between the outer peripheral surface of the output shaft 7 and the inner peripheral surface of the lock ring 51 that surrounds the output shaft 7, there are two types of wedge-shaped spaces formed by the recess 52 and having different directions.
50b are provided respectively, and the groove 5 in the lock ring 51 is provided.
A release projection 55 integrally formed on the ring gear 33 is located at 3 so as to be slidable in the radial direction. For this reason, the rotation range of the ring gear 33 with respect to the housing 10 is limited by the partition pieces 57 and 58 of the lock ring 51. The lock member 50a is for one-way rotation lock,
The lock member 50b is for locking in the other direction. Since the diameters of the lock members 50a, 50b are smaller than the height of the partition 57 side portion of the wedge-shaped space and larger than the height of the groove 53 side portion, the lock members 50a, 50b are located on the partition 57 side. Although it is in a floating state when it is located, when it is separated from the partition 57, it is caught between the outer peripheral surface of the output shaft 7 and the inner peripheral surface of the lock ring 51 to lock the output shaft 7 with respect to the housing 10.

FIG. 5 shows the appearance. In the figure, 1 is a main body, 9 is a bit mounted on the chuck 8, 11 is a switch handle, 12 is a rotation direction switching handle, and 13 is a power pack.

Next, the operation will be described. Now, when the motor 2 is rotated in the clockwise direction and the output shaft 7 is rotated in the direction of the arrow shown in FIG. 2, due to the characteristics of the planetary speed reducer, the ring gear 33
As shown in FIG. 2, the locking member 50b is moved to the partition 57 side by the releasing projection 55 so as to rotate in the opposite direction, and the locking member 50b is placed in the floating position. Further, the lock member 50a is
The rotation of the rotary shaft 7 feeds the wedge-shaped space to the partition 57 side. As a result, the lock members 50a and 50b do not hinder the rotation of the output shaft 7. When the motor 2 is rotated in the opposite direction, the release projection 55 reversely moves the lock member 50a to the partition piece 5.
Since the lock member 50b is moved to the 7 side and the lock member 50b moves to the partition 57 side with the rotation of the output shaft 7, the rotation of the output shaft 7 is not hindered. In particular, here, the surface of the release projection 55 on the side of the lock members 50a, 50b is an inclined surface, and the lock members 50a, 5b are
In order to float 0b from the peripheral surface of the output shaft 7, the lock member 50a,
There is no 50b dancing sound or load.

When the housing 10 is rotated in the tightening direction around the output shaft 7 for manual tightening while the rotation of the motor 2 is stopped, that is, the lock ring 51 with respect to the output shaft 7 is rotated. When it is rotated in the direction shown by the arrow in FIG. 3, the lock member 50a moves away from the partition 57, moves to the narrower side of the wedge-shaped space, and is caught between the lock ring 51 and the output shaft 7 to cause the housing 10 to move. Immediately lock the rotation of the output shaft 7 with respect to. Therefore, the housing 10 and the output shaft 7 are integrated, and the tightening can be performed by rotating the housing 10. When the housing 10 is turned in the opposite direction, the lock member 50b locks. The housing 10
When rotating the ring gear, the relative rotation between the housing 10 and the output shaft 7 in the initial stage causes the ring gear to rotate.
33 also tries to rotate, but in actuality, due to backlash and rattling of the gear, it hardly follows the minute rotation of the output shaft 7, so it does not move in the direction to release the lock by the lock members 50a, 50b. , So it is definitely locked. However, depending on the initial position of the release projection 55 of the ring gear 33, the lock members 50a and 50b may not move smoothly to the engaged position, but at this time, once,
Rotate it in the opposite direction to the one you want to turn. This does not pose a problem in view of the tool usage.

Of course, as shown in FIG. 4, the partition piece 58 and this partition piece
The springs 59, 5 are provided between the release projections 55 on both sides of the spring 58, respectively.
9 and the release projection 55 of the ring gear 33 has springs 59, 59
So that the lock members 50a, 50b do not prevent the lock members 50a, 50b from reaching the lock position, as shown in the figure, except when the motor 2 is rotated. If the projection 55 is located, the transition to the locked state can be ensured.

〔The invention's effect〕

As described above, in the present invention, the recess formed in the inner peripheral surface of the lock ring surrounding the output shaft and having the depth varying in the circumferential direction is formed between the outer peripheral surface of the output shaft and the inner peripheral surface of the lock ring. The output shaft is automatically locked by the lock part biting into the wedge-shaped space formed.When the output shaft is driven by rotating the motor, the initial rotation of the ring gear causes the ring gear to rotate. Since the release projection is automatically released to move the lock member to the unlock position, it is very easy to use as a rotating tool such as an electric screwdriver or an electric wrench, and ratchet noise becomes a problem. It does not require a complicated shaped part, and the recess formed in the inner peripheral surface of the lock ring forms a wedge-shaped space and the ring gear Since the release projection is provided for automatic release, the locking member does not lock the output shaft during electric drive, and reliable operation can be obtained with high reliability. .

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of an embodiment of the present invention, FIGS. 2 and 3 are sectional views taken along the line XX in FIG. 1, and FIG. 2 is a sectional view showing a released state at the time of forward rotation. Fig. 3 is a sectional view showing a locked state at the time of hand tightening, Fig. 4 is a sectional view of another embodiment,
FIG. 5 is a side view showing the external appearance. 7 is an output shaft, 33 is a ring gear, 34 is a carrier, 50a and 50b are lock members, and 51 is a lock member.
Is a lock ring, 52 is a recess, and 55 is a release projection.

Claims (2)

[Claims] 1. A lock ring fixed to a tool housing and having a recess on the inner peripheral surface, the depth of which varies in the circumferential direction, and an output arranged on the inner peripheral side of the lock ring. The output shaft is provided as a planet carrier of a planetary speed reducer, including a shaft and a lock member formed of a ball or a roller arranged in a wedge-shaped space surrounded by the outer peripheral surface of the output shaft and the recess of the lock ring. Along with the lock ring and the output shaft, the release member that locks the output shaft with respect to the tool housing by pressing the lock member in the circumferential direction of the output shaft to release it from the engaged position is a tool in the planetary speed reducer. A rotary tool provided on a ring gear which is rotatable within a predetermined angle with respect to a housing. 2. The rotary tool according to claim 1, wherein the releasing projection of the ring gear is biased by a spring toward a position that does not hinder the lock member from being bitten.