JPH06278048A - Device for adjusting torque of motor-driven rotary tool - Google Patents

Abstract

PURPOSE:To stably vary a torque value by providing a clutch handle which sets and adjusts the amount of compression of a spring according to the position of the stepped slope flat portion of the outer peripheral face of an adjustor ring. CONSTITUTION:In a torque adjusting device having an adjustor ring 23 and a clutch handle 25 disposed therein, rotation of the clutch handle 25 changes the supporting position of a protrusion 26 formed on the inner peripheral face of the handle and that of the flat portion 24a of the stepped slope 24 of the adjustor ring 23. The pressing force of a spring 22 which presses a steel ball 20 abutting on a front side 11c opposed to the direction of the axis of a clutch gear 11 can then be varied; i.e., the amount of compression of the spring 22 is set and adjusted so that the force to press the steel ball 20 can be varied. The amount of reaction force required to rotate the clutch gear 11 against a reaction force transmitted from a drive shaft 14 can thus be adjusted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a torque adjusting device for an electric rotating tool, and more particularly to a torque adjusting device for an electric rotating tool capable of adjusting a driving torque of a tool such as a bit mounted on a chuck.

[0002]

2. Description of the Related Art An electric rotary tool is a tool for transmitting a rotary torque from a drive shaft of a motor to a tool such as a bit mounted on a chuck through a planetary speed reduction mechanism or the like to perform screw tightening or the like. Usually, the driving torque of a bit or the like mounted on the chuck of an electric rotating tool can be changed and adjusted depending on the work object to be screwed. FIG. 6 is a perspective view showing a part of a configuration example of a conventional torque adjusting device for an electric rotary tool (Japanese Patent Publication No. 57-61554). In this electric rotary tool, a chuck (not shown) is attached to the tip of a drive shaft 32 that is decelerated from the drive shaft 31 of the motor 30 via a planetary reduction mechanism. A rear stage planetary gear 34, to which rotational torque is transmitted from a reduction mechanism using a front stage planetary gear 33, is rotatably supported on the drive shaft 32, and the planetary gear 34 is chevron-shaped at regular intervals in the circumferential direction of the front surface 35c. Protrusion 35
The a is meshed with the inner teeth 35b of the clutch gear 35 having the protruding shape. Further, the clutch gear 35 is arranged in the gear case 40, and the gear case 40 is integrally formed by the large cylindrical portion 41 and the small cylindrical portion 42, and the front surface 4 of the large cylindrical portion 41 is formed.
Holes 43 for accommodating and arranging the steel balls 50 are formed at regular intervals in the circumferential direction of 1a. The steel ball 50 is a gear case 4
It is arranged between the chevron-shaped projections 35a and 35a projecting on the front surface 35c of the clutch gear 35 arranged in the zero position.

Further, one end of the spring 44 has a steel plate 50 housed in a hole 43 formed in the front surface of the large cylindrical portion 41 of the gear case 40 via a thrust plate 45, and the steel ball 50 is accommodated in the clutch gear. It is arranged so as to press against the front surface 35c of 35 with a predetermined biasing force. The outer peripheral edge of the clutch plate 46, which is disposed in contact with the other end of the spring 44, is formed with three support claws 46a protruding in the radial direction.
a is formed in an arc surface shape that swells in the axial direction. The small cylindrical portion 42 of the gear case 40 is fitted into the hole 46b of the clutch plate 46. These thrust plate 45, spring 4
4, the clutch plate 46 and the like are accommodated in the clutch handle 47. Further, on the inner peripheral surface of the clutch handle 47, a step-like inclined surface 48 is formed as shown in FIG. 7 and FIG. 8 which is a sectional view taken along the line AA of FIG. The support claw 4 of the clutch plate 46 is provided on the flat portion 48a.
6a is abutted and supported. That is, the clutch handle 4
The biasing force of the spring 44 is adjusted by axially moving the support claw 46a of the clutch plate 46 that is in contact with the stepped inclined surface 48 of the clutch handle 47 by the rotation of 7.

When the drive shaft 32 is overloaded in this way, if the torque reaction force transmitted from the drive shaft 32 side to the clutch gear 35 via the planetary gear 34 is below a predetermined value, the steel ball 5
0 cannot pass the chevron projection 35a of the clutch gear 35, and the clutch gear 35 is stopped. But,
If the torque reaction force is equal to or greater than a predetermined value, the steel ball 50 urged by the spring 44 rides over the projection 35a on the front surface of the clutch gear 35 and passes through the planetary gear 34 to the clutch gear 35.
Rotates to stop the rotation of the drive shaft 32.

[0005]

As described above, the stepped inclined surface 48 is formed on the inner peripheral surface of the clutch handle 47, and the clutch plate 46 having the support claw 46a is biased by the spring 44, and the same flat portion is formed. Clutch handle 47 and clutch plate 46 (indicating claw 46
Producing a) is relatively complicated. Also, the spring 44
If the support claw 46a of the clutch plate 46 that is in direct contact with is axially moved along the stepped inclined surface 48 of the clutch handle 47, there is a risk of slippage and it becomes unstable.
There is a problem such as.

The present invention has been made in view of the above problems, and an object of the present invention is to enable smooth and stable operation when changing a torque setting value of a tool such as a bit. An object of the present invention is to provide a torque adjusting device for an electric rotary tool that is easy to assemble.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention has a clutch which is pressed by an urging force from one end of the spring to support the meshing, and In a torque adjusting device for an electric rotary tool capable of adjusting a driving torque by changing an urging force, a means for changing the urging force of the spring comprises a cylindrical portion and a flange portion, An adjuster ring in which an end portion is supported by an inner surface portion of the flange portion and an outer peripheral surface of a cylindrical portion is formed with an arcuate stepped inclined surface having a height in the axial direction, and the adjuster ring is fitted and inserted into the outer periphery of the adjuster ring. And a clutch handle having a protrusion on the inner peripheral side surface for setting and adjusting the amount of compression of the spring depending on the position of the flat portion of the step-like inclined surface of the surface.

[0008]

The operation when the torque adjusting device for an electric rotating tool is used as the above means will be described with reference to the reference numerals in the accompanying drawings.
When the clutch handle 25 is rotated, the support position between the protrusion 26 formed on the inner peripheral surface of the clutch handle 25 and the flat portion 24a of the stepped inclined surface 24 of the adjuster ring 23 is changed, whereby the shaft of the clutch gear 6 is changed. Spring 22 for pressing steel ball 20 in contact with front surface 11c facing in the direction
Can change the urging force of. That is, the pressing force on the steel ball 20 can be changed by setting and adjusting the compression amount of the spring 22. Thus, the magnitude of the reaction force required to rotate the clutch gear 11 with respect to the reaction force transmitted from the drive shaft 14 can be adjusted.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an axial sectional view of a torque adjusting device portion of an electric rotary tool of the present invention, and FIG. 2 is a perspective view showing its components. The sun gear 4 of the first stage is fitted to the drive shaft 2 of the motor 3 arranged in the case 1,
The first stage sun gear 4 meshes with a planetary gear 5 rotatably supported by a first stage planetary gear holding plate 6. The planetary gear 5 meshes with an internal gear 7 fixed to the case 1.

Next, a sun gear 8 of the second stage is formed on the opposite side of the planetary gear holding plate 6 of the first stage which pivotally supports the planetary gear 5, and the sun gear 8 is the second stage. Planetary gear holding plate 1
It meshes with a planetary gear 9 that is rotatably supported at 0.
Further, the planetary gear 9 meshes with internal teeth 11b formed on the inner peripheral surface of the clutch gear 11.

Reference numeral 12 is a gear case, which is a large cylindrical portion 12a.
And a small cylindrical portion 12b. The flange portion 12f of the large cylindrical portion 12a is formed with holes 13 at predetermined intervals in the circumferential direction, and the steel balls 20 are arranged in the holes 13. The upper and lower sides of the small cylindrical portion 12b are flat surfaces. Reference numeral 14 denotes a drive shaft on which a male screw 14a is threaded, and a chuck 15 for mounting a tool such as a bit (not shown) is attached thereto. A spline 14b is engraved on the other end of the drive shaft 14, and is fitted with the spline 10a engraved on the second stage planetary gear holding plate 10 to rotate integrally therewith. The clutch gear 11 is arranged in the large cylindrical portion 12a of the gear case 12, and the drive shaft 14 is arranged in the small cylindrical portion 12b so as to penetrate therethrough.
The front portion of No. 4 is supported by a thrust bearing including a bush 16, thrust plates 17 and 17, steel balls 18, and the like.

As shown in FIG. 2, projections 11a are formed at predetermined intervals in the circumferential direction on the front surface 11c of the clutch gear 11 constituting the clutch of the torque adjusting device, which faces the axial direction, and the projections 11a and the projections 11a are formed. Between the gear case
The steel balls 20 arranged in the holes 13 formed in the flange portion 12f of the sleeve 12 are arranged in contact with each other. The steel ball 20 is pressed against the flat surface portion of the front surface 11c facing the axial direction of the clutch gear 11 by the urging force from one end portion of the spring 22 via the thrust plate 21. Further, the other end of the spring 22 is brought into contact with and supported by an inner surface of a flange portion 23b of an adjuster ring 23 described later. Further, the adjuster ring 23 is biased by the spring 22 and is disposed inside a clutch handle 25 as a support member.

The steel ball 20 pressed against the front surface 11c of the clutch gear 11, which faces the axial direction, receives a reaction force from the chuck 15 side through the drive shaft 14 and the planetary gear 10 pivotally supported by the planetary gear holding plate 9. Even if (torque) is applied, if the reaction force is less than a predetermined value, it cannot ride over the projection 11a, so that the clutch gear 11 does not rotate, the drive shaft 14 rotates, and a predetermined rotational torque is applied from the motor 3. introduce. However, when a reaction force (torque) of a predetermined value or more acts from the chuck 15 side via the drive shaft 14 and the like, the steel ball 20 rides over the projection 11a, so that the clutch gear 11 starts rotating and the drive shaft 14 stops. It becomes a state.

FIG. 3 (A) is a side view of the adjuster ring 23, and FIG. 3 (B) is a front view as seen from the direction of arrow P in FIG. 3 (A). As described above, the adjuster ring 23 is formed by the cylindrical portion 23a and the flange portion 23b, and the end portion of the spring 22 is abutted and supported on the inner surface of the flange portion 23b. On the outer peripheral surface, a stepped inclined surface 24 having an arcuate shape and having a height in the axial direction is formed. In the case of this embodiment, the step-like inclined surface 24 is symmetrical with respect to the axis center.
Although a set is formed, three sets or more may be formed.

FIG. 4A is a sectional view of the clutch handle 25 in the axial direction, and FIG. 4B is a front view taken in the direction of arrow Q in FIG. 4A. An inner peripheral surface 25a of the clutch handle 25 has a stepped inclined surface 24 on the outer peripheral surface of the adjuster ring 23.
The protrusion 26 is formed so as to be in contact with and supported by the flat portion 24a. By rotating the clutch handle, the protrusion 26 can change the position where the protrusion 26 abuts against and is supported by the flat portion 24a of the stepped inclined surface 24 on the outer peripheral surface of the adjuster ring 23.

FIG. 5 is an axial cross-sectional view of an electric rotary tool having a torque adjusting device showing the arrangement of the adjuster ring 23 and the clutch handle 25. When the clutch handle 25 is rotated as described above, the support position between the protrusion 26 formed on the inner peripheral surface 25a of the clutch handle 25 and the flat portion 24a of the stepped inclined surface 24 of the adjuster ring 23 is changed. The biasing force of the spring 22 that presses the steel ball 20 that is in contact with the front surface 11c of the clutch gear 11 that faces the axial direction can be changed. That is, the pressing force on the steel ball 20 can be changed by setting and adjusting the compression amount of the spring 22. Thus, the magnitude of the reaction force required to rotate the clutch gear 11 with respect to the reaction force transmitted from the drive shaft 11 can be adjusted.

[0017]

Since the torque adjusting device for an electric rotary tool of the present invention is configured as described above in detail, the torque value applied to a tool such as a bit can be stably changed.
In addition, the click operation when rotating the clutch handle is extremely smooth, and the electric rotary tool that is easy to operate can be provided, and the manufacturing and assembly are easy.

[Brief description of drawings]

FIG. 1 is an axial sectional view of a torque adjusting device portion of an electric rotating tool according to the present invention.

2 is a perspective view showing a component part of FIG. 1. FIG.

FIG. 3 (A) is a front view of the adjuster ring as seen from the front, and FIG. 3 (B) is a side view.

4A is an axial sectional view of a clutch handle, and FIG. 4B is a front view seen from the rear.

FIG. 5 is an axial sectional view of a torque adjusting device for an electric rotating tool showing an arrangement state of an adjuster ring and a clutch handle.

FIG. 6 is a perspective view showing a part of a configuration example of a conventional torque adjusting device for an electric rotary tool.

FIG. 7 is a front view of a conventional clutch handle as viewed from the rear.

8 is a cross-sectional view taken along the line AA of FIG.

[Invention of code]

1 Case 3 Motor 4, 8 Sun Gear 5, 9 Planetary Gear 6, 10 Planetary Gear Holding Plate 7 Internal Gear 11 Clutch Gear 12 Gear Case 13 Hole 14 Drive Shaft 20 Steel Ball 21 Thrust Plate 22 Spring 23 Adjuster 23a Cylindrical part 23b Flange part 24 Stepped inclined surface 24a Flat part 25 Clutch handle 26 Protrusion

Claims (1)

[Claims] 1. A clutch having a clutch that is pressed by an urging force from one end of the spring to support the meshing, and the driving torque can be adjusted by changing the urging force of the spring. In the torque adjusting device for an electric rotating tool, the means for changing the urging force of the spring comprises a cylindrical portion and a flange portion, and the other end portion of the spring is supported by the inner surface portion of the flange portion and the outer peripheral surface of the cylindrical portion. The amount of compression of the spring is adjusted by the adjuster ring having an arcuate stepped inclined surface having a height in the axial direction, and the position of the flat portion of the stepped inclined surface on the outer peripheral surface of the adjuster ring that is fitted and inserted. A torque adjusting device for an electric rotating tool, comprising: a clutch handle having a protrusion for setting adjustment formed on an inner peripheral surface thereof.