JPH11207650A - Tightening torque adjusting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it difficult to generate malfunction due to deformation to a clutch plate or the like. SOLUTION: This tightening torque adjusting device is provided with a torque clutch which disconnects power transmission to an output shaft 9 by pushing up a clutch plate 36 against a clutch spring 37 with an increase in load torque, and an adjusting member 34 which receives one end of the clutch spring 37 whose other end is brought into contact with the clutch plate 36, whereas spring force at which the clutch spring 37 pressurizes the clutch plate 36 due to the movement of the adjusting member 34 is kept adjustable, and a regulating part is formed at the adjusting member 34, which inhibits movement against the clutch spring 37 of the clutch plate 36 by a contact with the clutch plate 36. The adjusting member 34 which is engaged with a male screw formed at the outer periphery of an output shaft retaining part, and conducts movement in an axial direction by its rotation, is provided with the regulating part 342 which comes into contact with the annular clutch plate 36 disposed at the outer periphery of the output shaft retaining part, on the outer periphery side of the clutch spring 37 disposed at the outer periphery of the output shaft retaining part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tightening torque adjusting device used for a tightening tool such as an electric screwdriver, that is, a torque clutch that cuts off power transmission when the tightening torque reaches a set value. The present invention relates to a tightening torque adjusting device.

[0002]

2. Description of the Related Art Conventionally, there have been provided various tools provided with a torque clutch for interrupting power transmission when a tightening torque has reached a set value. When the load torque becomes larger than a set value, one clutch member repeatedly rides on a protrusion on the other clutch member to perform idling when the load torque becomes larger than a set value. In general, a device that shuts off power transmission is used, and the setting value is changed by adjusting a spring force of a clutch spring that biases the clutch member toward the other clutch member. Is generally used.

FIG. 7 shows an example of a conventional tightening torque adjusting device. Sun gear 21 provided on a rotating shaft 20 of the motor
A plurality of planet gears 22 supported by a carrier 24 mesh with a ring gear 23 fixed to the inner surface of the gear case 8, and a sun gear 25 and a ring gear 27 formed integrally with the carrier 24. A plurality of planet gears 26 are engaged. The carrier 28 supporting the planetary gear 26 integrally includes a sun gear 29 of a third stage planetary mechanism, and the sun gear 29 and the gear case 8
The ring gear 31 rotatably disposed inside and the planetary gear 3
0 is engaged. The carrier 32 supporting the planetary gear 30 is connected to the output shaft 9 via a lock plate 60 in a lock mechanism. The ring gear 27 is slidable in the axial direction. In the state shown in the upper part of FIG. 7, the ring gear 27 meshes with the carrier 28 and rotates integrally with the carrier 28. In the state shown in the lower part of FIG. The rotation is locked by meshing with the case 8, and the shift is performed by switching between the two states. The lock mechanism is for automatically locking the output shaft 9 at the time of manual tightening work.
Here, the description is omitted.

The tightening torque adjusting device utilizes the freely rotatable ring gear 31 in the third stage planetary mechanism, and includes a ridge 310 formed on an axial end surface of the ring gear 31. A ball 33 disposed in a through-hole provided to penetrate the step portion of the gear case 8 in the axial direction and engaging with the ridge 310; and a small-diameter distal end outer peripheral surface of the gear case 8 Adjustment member 34 disposed in
And a clutch spring 37 having one end elastically contacting the adjustment member 34 and the other end elastically contacting the ball 33 via the clutch plate 36.

The adjusting member 34 has an internal thread on its inner peripheral surface which is screwed with a male screw formed on the outer peripheral surface of the small diameter portion of the gear case 8, and reciprocates in the axial direction with respect to the gear case 8. ing. Also, the clutch spring 37 and the ball 33
The annular clutch plate 36 located between the gear case 8 and the gear case 8 is non-rotatable and axially movable.

Now, when the adjusting member 34 is at the position shown in the upper part of FIG. 7, the output of the motor is such that the ball 33 is locked by the first and second stage planetary mechanisms and the bias by the clutch spring 37. Ring gear 31 whose rotation is hindered by
And transmitted to the output shaft 9 by the third stage planetary mechanism having The load torque applied to the ring gear 31 is applied to the ball 3 provided by the clutch spring 37.
When the engagement force between the ring gear 3 and the ridge 310 of the ring gear 31 becomes higher, the ring gear 31 pushes the ball 33 against the clutch spring 37 and starts idling. Ring gear 3
Since the torque clutch including the ball 1 and the ball 33 slips, the tightening torque is limited.

If the amount of compression of the clutch spring 37 is increased by moving the adjusting member 34 to the left in FIG. 7, the engagement force between the ball 33 and the ring gear 31 increases, so that the ring gear 31 idles. The starting load torque increases. That is, the tightening torque increases. Then, by moving the adjusting member 34 further to the left side to bring the pressing protrusion 341 provided on the adjusting member 34 into contact with the clutch plate 36 as shown in the lower part of FIG. In order to be unable to retreat by being pushed by the ridge 32,
The torque from which the torque clutch starts to slide is infinite, and the state is suitable for use as an electric drill.

[0008]

By the way, even in the locked state where the pressing plate 341 is brought into contact with the clutch plate 36 to prevent the movement of the clutch plate 36 as described above, if the load torque becomes large, the ring gear 31 will not move. Ridge 310 pushes up the clutch plate 36 via the ball 33, but the position where the ball 33 contacts the clutch plate 36 depends on the position of the adjusting member 3.
The fourth pressing protrusion 341 is located on the outer peripheral side from the position where it comes into contact with the clutch plate 36.

Therefore, in the locked state in which the movement of the clutch plate 36 is prevented by bringing the pressing projection 341 into contact with the clutch plate 36, if the clutch plate 36 is repeatedly pushed up by the ball 33 with a large load torque, the clutch plate 36 will not be moved. May be deformed, and the pressing protrusion 341 of the adjusting member 34 may be crushed. In order to release the lock of the clutch plate 36 by a slight angle rotation of the adjusting member 34, a portion of the clutch plate 36 where the pressing protrusion 341 contacts is a protruding piece projecting inwardly. Deformation is likely to occur.

SUMMARY OF THE INVENTION The present invention has been made in view of the foregoing, and an object of the present invention is to provide a tightening torque adjusting device which is less likely to malfunction due to deformation of a clutch plate.

[0011]

SUMMARY OF THE INVENTION The present invention provides a torque clutch for interrupting power transmission to an output shaft by pushing up a clutch plate against a clutch spring with an increase in load torque, and a torque clutch. An adjusting member for receiving the other end of the clutch spring having one end abutting on the clutch plate, wherein the spring force of the clutch spring pressing the clutch plate by the movement of the adjusting member can be adjusted, and the clutch plate can be adjusted. In the tightening torque adjusting device, in which the regulating member is provided with a regulating portion for preventing the clutch plate from moving against the clutch spring by contacting with the outer peripheral surface of the output shaft holding portion, the regulating member is screwed with the male screw provided on the outer periphery of the output shaft holding portion. The adjusting member, which moves in the axial direction by means of the clutch, is provided with a restricting portion that comes into contact with an annular clutch plate disposed on the outer periphery of the output shaft holding portion, and a clutch disposed on the outer periphery of the output shaft holding portion. It is characterized in that it comprises on the outer peripheral side of the spring.

It is preferable that the adjusting member has a regulating portion at both sides of the contact point between the member that pushes up the clutch plate and the clutch plate with an increase in the load torque. It is preferable that a regulating portion is provided on both the inner peripheral side and the outer peripheral side of the contact point between the member that pushes up the clutch plate and the clutch plate with an increase in the load torque. In this case, the adjusting member may be formed in a double cylindrical shape, and a regulating portion may be provided at each end of the inner cylinder and the outer cylinder having a space between them for disposing the clutch spring.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to an example of the illustrated embodiment. FIG. 4 shows a tightening tool provided with a tightening torque adjusting device according to the present invention. A driver bit and a drill bit are selectively attached to the chuck 90 as a part. Also, the power source is a storage battery in a storage battery pack (not shown) which is detachably mounted on a handle portion of the main body 1, and the motor 2 is supplied with power through a switch unit 16 which is turned on when the trigger handle 15 is pulled. It is a battery-powered electric type that is used as a power source. A gear case 8 having the configuration shown in FIG. 1 and a tightening torque setting member are accommodated between the motor 2 and the output shaft 9 having the chuck 90 in the main body 1. A clutch handle 3 is rotatably attached to the distal end of the main body 1, and a protrusion that slidably engages with an axial vertical groove formed on the inner surface of the clutch handle 3 is provided as an adjusting member. Since the outer peripheral surface 34 is provided, the adjusting member 34 reciprocates in the axial direction with respect to the gear case 8 with the rotation of the clutch handle 3. In FIG. 4, reference numeral 65 denotes a speed change handle. The ring gear 27 moves forward and backward by moving the speed change handle 65 forward and backward.

The structure of each member arranged in the gear case 8 is as follows.
Since it is the same as that shown in the conventional example, only the adjusting member 34 and the clutch plate 36 will be described here. The adjusting member 34 used here is a clutch plate 36
The adjusting member 34 for positioning the clutch spring 37 between the inner cylinder and the outer cylinder includes a plurality of pressing projections 3 from the end face of the inner cylinder on the clutch plate 36 side.
41 at the same time as the clutch plate 36 in the outer cylinder.
A plurality of pressing projections 342 project from the side end surface.
The pressing protrusion 341 on the inner peripheral side and the pressing protrusion 34 on the outer peripheral side
2 is provided at a position shifted in the circumferential direction as shown in FIG.

On the other hand, as shown in FIG. 3, the clutch plate 36 is provided with a portion A where the pressing protrusion 341 contacts, as a protruding piece protruding toward the inner peripheral side, and a portion B where the pressing protrusion 342 makes contact with the adjusting member 34 side. It is provided as a convex portion protruding toward. 3 shows the position of the ball 33, the clutch spring 37 is brought into contact with the clutch plate 36 inside the circle passing through the point where the ball 33 comes into contact, and the part B with which the pressing projection 342 comes into contact is 3
3 can be located in the vicinity of the point where it contacts.

Since the pressing projection 342 located on the outer peripheral side of the clutch spring 37 locks the clutch plate 36, the locking of the clutch plate 36 is performed by the pressing projection 341 located on the inner peripheral side of the clutch spring 37. Compared to what you do,
The deformation of the clutch plate 36 is hardly caused, and not only the pressing protrusion 342 but also the pressing protrusion 341 is used in combination with the inner peripheral side and the outer peripheral side of the clutch spring 37 (the ball 33 and the clutch plate Since the clutch plate 36 is locked between the inner peripheral side and the outer peripheral side of the circle passing through the contact point between the clutch plate 36 and the clutch plate 36, further deformation of the clutch plate 36 is less likely to occur. In addition, since the number of contact points of the adjustment member 34 with the clutch plate 36 increases, each pressing projection 3
The surface pressure applied to 41 and 342 is reduced, and therefore, the pressing projections 341 and 342 are hardly crushed.

[0017]

As described above, in the present invention, the adjusting member which is screwed with the male screw provided on the outer periphery of the output shaft holding portion and moves in the axial direction by its rotation is arranged on the outer periphery of the output shaft holding portion. Since the regulating portion for contacting the formed annular clutch plate is provided on the outer peripheral side of the clutch spring disposed on the outer periphery of the output shaft holding portion, the regulating portion is brought into contact with the clutch plate to lock the clutch plate. In this state, even if a pushing force is applied to the clutch plate due to an increase in load torque, the clutch plate is unlikely to be deformed.

Further, if the adjusting member is provided with regulating portions on both sides of the contact point between the member that pushes up the clutch plate and the clutch plate as the load torque increases, the adjusting member as a torque clutch Deformation during locking of the clutch plate can be reliably prevented without impairing the function at all. In particular, when the regulating portion is provided on both the inner peripheral side and the outer peripheral side of the contact point between the member that pushes up the clutch plate and the clutch plate with an increase in the load torque,
A more preferable result can be obtained. In this case, the adjusting member is formed in a double cylindrical shape, and the regulating members are provided at the respective ends of the inner cylinder and the outer cylinder having a space for disposing the clutch spring therebetween. Can be realized.

[Brief description of the drawings]

FIG. 1 is a sectional view of an example of an embodiment of the present invention.

FIG. 2 shows an adjusting member according to the first embodiment, wherein (a) is a rear view,
(b) is a sectional view.

FIG. 3 is a front view of the clutch plate.

FIG. 4 is a sectional view of a tightening tool provided with the same.

FIG. 5 is a side view of the same gear block.

FIG. 6 is a front view of the same gear block.

FIG. 7 is a sectional view of a conventional example.

[Explanation of symbols]

 33 Ball 34 Adjusting member 36 Clutch plate 37 Clutch spring 341 Pressing protrusion 342 Pressing protrusion

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[Procedure amendment]

[Submission date] June 15, 1998

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] Fig. 4

[Correction method] Change

[Correction contents]

FIG. 4

Claims (4)

[Claims] 1. A torque clutch for interrupting power transmission to an output shaft by pushing up a clutch plate against a clutch spring with an increase in load torque, and having one end of the torque clutch in contact with the clutch plate. An adjusting member for receiving the other end of the clutch spring, wherein the spring force of the clutch spring pressing the clutch plate can be adjusted by movement of the adjusting member, and the clutch spring of the clutch plate comes into contact with the clutch plate. In the tightening torque adjusting device in which the regulating member for preventing the opposing movement is provided on the adjusting member, the adjusting member that is screwed with a male screw provided on the outer periphery of the output shaft holding portion and moves in the axial direction by its rotation, It is characterized in that a regulating portion which comes into contact with an annular clutch plate arranged on the outer periphery of the output shaft holding portion is provided on the outer periphery side of the clutch spring arranged on the outer periphery of the output shaft holding portion. Tightening torque adjustment device. 2. The adjusting member according to claim 1, wherein the adjusting member includes regulating portions at both sides of a contact point between the member that pushes up the clutch plate and the clutch plate with an increase in load torque. Tightening torque adjustment device. 3. The adjusting member has regulating portions at both inner and outer peripheral sides of a contact point between the member that pushes up the clutch plate and the clutch plate as the load torque increases. 3. The tightening torque adjusting device according to claim 1, wherein: 4. The adjusting member is formed in a double cylindrical shape,
4. The tightening torque adjusting device according to claim 3, wherein a regulating portion is provided at each end of the inner cylinder and the outer cylinder having a space between them as an arrangement space of the clutch spring.