JP2525274Y2 - Tightening torque adjustment device for rotary tools - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a tightening torque adjusting device for a rotary tool such as an electric dryer bar or an electric wrench.

[Conventional technology]

Conventionally, as a tightening torque adjustment device for rotating tools,
The one disclosed in Japanese Utility Model Laid-Open No. 1-138673 has been proposed. The tightening torque adjusting device shown therein will be described below with reference to FIGS. 7 and 8.

A two-stage planetary reduction mechanism is provided in a power transmission path from the motor 4 to the output shaft 48, and a ring gear 47 in the second-stage planetary reduction mechanism is freely rotatable with respect to the gear case 8. The ring gear 47 is provided with a ridge 50 on its tip end surface.

Male screw 80 formed on the outer peripheral surface at the tip of gear case 8
An adjusting member 52 provided with a female screw 56 screwed with the rotating tool main body 1 is disposed at a tip end portion of the rotary tool main body 1. Further, a clutch handle 10 that is rotatable with respect to the rotary tool main body 1 is disposed at a distal end portion of the rotary tool main body 1. The adjusting member 52 has a projection 55 projecting from the outer peripheral surface thereof engaged with an axial longitudinal groove 18 formed on the inner surface of the clutch handle 10, whereby the adjusting member 52 is integrated with the clutch handle 10. It is designed to rotate. Then, the ball 51 is moved to the gear case 8
Is disposed in the through hole 16 provided in the stepped portion of the clutch spring 53.
Is disposed between the adjusting member 52 and the ball 51 so that the ball 51 comes into contact with one surface of the ring gear 47 provided with the ridge 50 by the bias of the clutch spring 53. Furthermore,
A thrust plate 54 is arranged between the ball 51 and the clutch spring 53, and the spring load of the clutch spring 53 is applied to the ball 51 via the thrust plate 54. Thrust plate 54
Has a projection 54b projecting from the outer peripheral edge thereof, and by engaging the projection 54b with a concave portion 19 formed on the inner peripheral surface of the clutch handle 10, the thrust plate 54 rotates integrally with the clutch handle 10. It has been. The thrust plate 54 is
As shown in the figure, a plurality of click engaging portions 54a are juxtaposed in the rotation direction. The click engagement portion 54a is formed of a hole having a diameter into which a part of the ball 51 fits.

As long as the load torque is small, the rotation of the ring gear 47 is prevented by engagement with the ball 51, so that power is transmitted from the motor 4 to the output shaft 48. However, the load torque applied to the ring gear 47 is reduced by the ball 51 and the ring gear.
If the engagement force with the motor 47 becomes larger, the ring gear 47 starts idling, so that the rotation of the motor 4 is not transmitted to the output shaft 48.

When the clutch handle 10 is rotated, the adjusting member 52 rotates together with the clutch handle 10. At this time, since the adjusting member 52 is screwed into the gear case 8, the adjusting member 52 moves in the axial direction, and the clutch The compression amount of the spring 53 is changed. As a result, the engagement force between the ball 51 and the ring gear 47 applied to the ball 51 by the clutch spring 53 via the thrust plate 54 changes, and the load torque at which the ring gear 47 starts to idle due to this changes. Change. Therefore, the tightening torque can be adjusted.

By the way, the rear side of the ring gear 47 is received by pins 59, 59 attached so as to penetrate the gear case 8, and the ring gear 37 is immovable in the axial direction. Of the ball 51
However, while compressing the clutch spring 53, the clutch spring 53 collides with the end face of the ring gear 47 due to the bias of the clutch spring 53, and an axial vibration is generated. The axial vibration generates a component force for rotating the clutch handle 10 and the adjusting member 52 at the screw-engaged portion between the adjusting member 52 and the gear case 8.

However, the thrust plate 54 rotates integrally with the clutch handle 10 as described above,
Since the click engagement portion 54a into which the 51 is fitted is provided, even if the adjusting member 52 and the clutch handle 10 try to rotate, the rotation is prevented by the engagement between the engagement portion 54a of the thrust plate 54 and the ball 51. Therefore, the tightening torque does not change due to vibration.

In addition, when the clutch handle 10 is rotated to adjust the tightening torque, the thrust plate 54 rotates from the state where a certain click engaging portion 54a is engaged with the ball 51, and the click engaging portion 54a Is disengaged from the ball 51, the thrust plate 54 rides on the ball 51,
The rotation of 54 causes the next engagement portion 54a to engage with ball 51.
As described above, since the engagement of the ball 51 changes from one click engagement portion 54a to another click engagement portion 54a, an operation with a click feeling can be obtained when the clutch handle 10 is rotated.

[Problems to be solved by the invention]

In such a torque adjusting device, the clutch handle 10
When the clutch spring 53 is operated in a direction to increase the adjustment torque, the clutch spring 53 is compressed by the movement of the adjustment member 52, and the click engagement portion 54a of the thrust plate 54 is moved to the other click engagement portion 54a. When moving, the thrust plate 54 rides on the ball 51 and is also compressed by moving in the direction of compressing the clutch spring 53. Therefore, when the compression amount of the clutch spring 53 increases, the clutch handle
The operation force of 10 becomes very large, and it becomes difficult to operate.

In particular, there is a problem that it is difficult to operate the clutch handle in the maximum torque state where the clutch spring is close to the close contact state.

The present invention has been made in view of the above circumstances, and the purpose thereof is to make it difficult to operate the clutch handle when the adjustment torque is increased and the compression amount of the clutch spring is increased. An object of the present invention is to provide a torque adjusting device for a rotary tool.

[Means for solving the problem]

In order to solve such a problem, the torque adjusting device of the present invention has an arc-shaped groove connecting adjacent click engagement portions on one surface of the thrust plate facing the ball.

[Action]

According to the above configuration, when the thrust plate rotates integrally with the clutch handle, the ball engaged with the click engagement portion of the thrust plate moves to another engagement through the groove, so that the thrust plate is moved. Since the amount of riding on the ball is reduced and the amount of compression of the clutch spring is mainly due to the movement of the adjusting member, it is possible to prevent the operating force of the clutch handle from becoming extremely large.

〔Example〕

Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 to 4 and FIG. The same members as those in the conventional example are denoted by the same reference numerals in the drawings, and description thereof will be omitted.

This rotary tool is an electric drill driver in which a driver bit or a drill bit 9 is detachably attached to the tip of the output shaft 48.

The planetary reduction mechanism housed in the rotary tool body 1 is
It is configured as follows. A plurality of planetary gears 42 supported by a carrier 44 mesh with a sun gear 41 provided on the output shaft of the motor 4 and a ring gear 43 fixed to the inner surface of the gear case 8 to form a first stage planetary reduction mechanism. Is configured. A plurality of planet gears 46 supported by an output shaft 48 mesh with a sun gear 45 formed integrally with the carrier 44 and a sun gear 47 supported rotatably with respect to the gear case 8, A second stage planetary reduction mechanism is configured. The output shaft 48 is supported by the bearing 15 on the small-diameter portion 8b of the gear case 8, and has a bit insertion hole 49 provided at the end surface.

A chuck is provided at the tip of the output shaft 48. This chuck has a hole 48a with a polygonal bit insertion hole 49
The ball 60 is formed on the peripheral surface of the output shaft 48 having
A C-shaped leaf spring 61, which is disposed at 48 a and biases the ball 60 inward, is attached to the outer peripheral surface of the ball 60.

The drill bit or driver bit 9 is configured to have an annular groove 90 on the peripheral surface of the base end portion having a polygonal cross section. When the drill bit or the driver bit 9 is inserted into the bit insertion hole 49, the ball 60 By being elastically locked in the groove 90 by the urging force, it is held by the chuck. The attachment / detachment of the bit 9 to / from the chuck can be easily performed by removing / inserting.

The tightening torque adjusting device includes a clutch portion including a freely rotatable ring gear 47 in the second-stage planetary reduction mechanism. The ring gear 47 has a ridge 50 formed on its axial end face. The tightening torque adjusting device is disposed in a through hole 16 that axially penetrates a step between the clutch portion and the large-diameter portion 8a and the small-diameter portion 8b of the gear case 8. An engaging ball 51;
An adjusting member 52 disposed on the outer peripheral surface of the small diameter portion 8b of the gear case 8;
A clutch spring 53 having one end elastically contacting the adjusting member 52 and the other end elastically contacting the ball 51 via a thrust plate 54; and a clutch handle rotatably attached to the distal end of the rotary tool body 1. 10 is the main component.

The above-mentioned tightening torque adjusting device enables the tightening torque to be adjusted in six stages, and therefore, the thrust plate 54
The click engagement portion 54a has a set of six click engagement portions 54a-1 to 54a-6 in the first to sixth stages, and three sets thereof are provided. Three balls 51 are provided so as to correspond to the three sets of the click engagement portions 54a one by one. In addition, the through-hole 16 of the gear case 8 in which the click engagement portion 54a of the thrust plate 54 and the ball 51 are arranged is formed so that these balls 51 are simultaneously engaged with the click engagement portions of the same step of each set. Have been. First stage click engagement part 54
When a-1 is engaged with the ball 51, the tightening torque is the minimum, and thereafter, the click engagement portion 54a of the second to fifth steps is used.
The tightening torque increases in order as the position moves from −2 to 54a−5. The click engagement portion 54a-6 of the sixth stage is the ball 51
When the engaging member is engaged, the adjusting member 52 moves to the thrust plate 54 side to the full extent and directly presses the thrust plate 54 so that the tightening torque adjusting device does not work. Note that the first-stage click engagement portion 54a-1 and the sixth-stage click engagement portion 54a-6 of the adjacent pair are also used.

The arc-shaped groove 54c is a surface of the thrust plate 54 facing the ball 51, and a fifth-stage click engagement portion 54a-5,
The click engaging portions 54a-5 and 54a- are formed between the click engaging portions 54a-6 of the sixth stage adjacent thereto.
6 are connected by a groove 54c. This groove is formed in a U-shaped cross section.

Next, the operation of the torque adjusting device will be described. First
In the figure, when the clutch handle 10 is rotated counterclockwise, the tightening torque of the tightening torque adjusting device increases. FIGS. 4 (a) to 4 (c)
This shows a state in which the click engagement portion 54a-5 at the stage moves to the click engagement portion 54a-6 at the sixth stage. When the fifth-stage click engagement portion 54a-5 is engaged with the ball (fourth
From FIG. (A), when the clutch handle 10 is rotated,
The adjustment member 52 moves to the right and compresses the clutch spring 53. At this time, the engagement between the click engaging portion 54a-5 and the ball 51 is released, and the groove 54c passes on the outer peripheral surface of the ball 51 (FIG. 4 (b)). Therefore, the thrust plate 54 hardly compresses the clutch spring 53, and the compression of the clutch spring 53 is suppressed only by the movement of the adjustment member 52, so that an increase in the operating force of the clutch handle 10 can be suppressed. Further, the operation of the clutch handle 10 does not become difficult due to the adjustment member 52 moving toward the thrust plate 54 colliding with the thrust plate 54 riding on the ball 51.

When the thrust plate 54 further rotates and the sixth-stage click engagement portion 54a-6 engages with the ball 51, the tip of the adjusting member 52 moves to the thrust plate 54 side to the full extent, and the thrust plate 54 is directly moved. Press down. Therefore, the ball 51 cannot get over the ridge 50 of the ring gear 47, and the tightening torque adjusting device does not work (FIG. 4 (c)). This provides a state suitable for use as an electric drill that does not require tightening torque adjustment.

Another embodiment of the present invention will be described with reference to FIGS.

In the present embodiment, the groove 54c is formed by
It is formed between the click engagement portions of the second through sixth click engagement portions 54a-6, and each click engagement portion is connected by a groove 54c. Moreover, as shown in FIG. 6, these grooves 54c form the shallowest groove connecting the second-stage click engagement portion 54a-2 and the third-stage click engagement portion 54a-3, The depth of the groove is increased in order, and the click engagement portion 54a-5 of the fifth stage is formed.
The groove connecting the click engagement portion 54a-6 of the sixth step is formed deepest. First-stage click engagement portions 54a-1 and 2
No groove 54c is formed between the click engaging portion 54a-2 of the step.

The operation of the tightening torque adjusting device configured as described above will be described below. When the clutch handle 10 is rotated in a direction to increase the tightening torque, the clutch spring 53
Is compressed by the adjusting member 52, and the operating force of the clutch handle 10 also increases. On the other hand, since the groove 54c is gradually deepened, the amount of the thrust plate 54 riding on the ball 51 is gradually reduced when moving from one click engaging portion 54a to the next click engaging portion 54a. Therefore, although the rate of increase in the amount of compression of the clutch spring 53 by the adjustment member 52 is constant, the rate of increase in the amount of compression by the thrust plate 54 decreases as the number of steps of the click engagement portion 54a increases. However, the rate at which the amount of compression of the clutch spring 53 increases decreases as the tightening torque increases. This allows the clutch spring
When the compression amount of 53 increases, the increase in the operating force of the clutch handle 10 is suppressed.

[Effect of the invention]

Since the tightening torque adjusting device for a rotary tool according to the present invention is configured as described above, when the thrust plate rotates integrally with the clutch handle, the ball engaged with the engaging portion passes through the groove. The amount of movement of the thrust plate on the ball is reduced due to the movement to the other engagement, and the amount of compression of the clutch spring is limited only by the movement of the adjustment member, so that an increase in the operating force of the clutch handle can be suppressed. It has the effect of being able to.

[Brief description of the drawings]

FIG. 1 is a sectional view of an embodiment of the present invention, and is a sectional view taken along line AA of FIG. 7, FIG. 2 is a perspective view of the thrust plate, FIG. 3 and FIG. FIGS. 5A to 5C are cross-sectional views showing the operation of the main part at the time of torque adjustment, FIG. 5 is a perspective view of a thrust plate according to another embodiment of the present invention, and FIG. FIG. 7 is a longitudinal sectional view of a rotary tool of each embodiment and a conventional example, and FIG. 8 is a sectional view taken along line AA of FIG. 7 showing a conventional example. 1 ... rotating tool body, 10 ... clutch handle, 51 ...
Ball, 52 ... adjustment member. 53 ... clutch spring, 54 ... thrust plate, 54a, 54a-1
5454a-6: click engaging portion, 54c: groove. 23 ... Pressing part.

Claims (1)

(57) [Scope of request for utility model registration] 1. A clutch handle rotatably disposed at a cylindrical distal end of a rotary tool main body, and a clutch handle rotatably disposed in the rotary tool main body in an axial direction and capable of being stopped at an arbitrary position. An adjusting member, an engaging portion provided between the adjusting member and the clutch handle, and configured to move the adjusting member in the axial direction by rotating the clutch handle, a clutch portion for torque adjustment, and the clutch portion. A clutch spring that is disposed between the adjusting member and sets a sliding torque of the clutch unit by a spring load; a ball provided on the clutch unit and receiving a spring load of the clutch spring; A thrust plate that is arranged to rotate integrally with the clutch handle, and a plurality of thrust plates are arranged on the thrust plate in the rotation direction in accordance with the magnitude of the slip-out torque of the clutch portion. In a rotary tool tightening torque adjusting device, one of which includes a click engaging portion that engages with the ball, a rotating tool tightening torque adjusting device corresponding to at least one of the plurality of click engaging portions, in which the slip-out torque in the clutch portion is large. A tightening torque adjusting device for a rotary tool, wherein adjacent click engaging portions of the click engaging portion are connected by an arc-shaped groove formed on one surface of the thrust plate facing the ball.