JP2001121445A - Torque wrench - Google Patents

Abstract

PROBLEM TO BE SOLVED: To develop a torque wrench constituted so that generation can be effectively suppressed of excessively tightening torque (over torque) to a thread tightened treaded screw. SOLUTION: This torque wrench has a slide top energized in a tip end part direction of a torque wrench handle member in its inside by receiving elastic force of a spring, toggle roller supported at a tip end part of this slide top, and a head member supported capable of oscillating in a tip end part of the torque wrench handle member further with a curved recessed part provided fitting partly the toggle roller by elastic force of the spring.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is intended to effectively suppress the occurrence of excessive fastening torque (overtorque) on a screw to be fastened during a screw fastening operation using a torque wrench. The present invention relates to a torque wrench configured as described above.

[0002]

2. Description of the Related Art FIG. 1 shows a general fastening torque characteristic at the time of a screw tightening operation for tightening a screw such as a bolt and a nut using a torque wrench provided with a torque detecting mechanism such as a toggle link. 5, the fastening torque (T) for the screw to be fastened increases from the time when the fastening operator starts the screw fastening operation using the torque wrench, and the fastening torque (T) is reduced. When the set torque value of the torque wrench is reached, the above-described torque detection mechanism operates to inform the operator intuitively that the screw tightening torque has reached the set torque value.

[0003]

The operation of the torque detecting mechanism causes the fastening torque to drop momentarily by ΔT.
For example, an unfamiliar screw tightening operator may use an excessive torque (T) that is greater than or equal to the tightening torque (T) due to inertia at the time of screw fastening.
2) That is, an overtorque (T2) is generated. Since the over-torque generated in this manner causes cutting of a screw to be fastened or breakage of a body to be fastened, the development of an over-torque-less torque wrench capable of effectively suppressing the occurrence of over-torque during screw fastening work. Is required.

SUMMARY OF THE INVENTION The present invention has been made in order to meet such a demand. When an over-torque occurs after the operation of a torque detecting mechanism incorporated in a torque wrench, an over-torque absorbing mechanism capable of absorbing the over-torque is provided. In addition to ensuring the prevention of over-torque during screw tightening work using a torque wrench, the over-torque absorption mechanism that is absorbed immediately after the screw tightening torque reaches the set torque provides a sudden over-torque To improve impact safety so that accidents such as hitting the worker's hand or arm with other objects due to the inertia force during screwing work by the screw tightening worker do not occur, Furthermore, it is possible to suppress the free rotation of the torque wrench handle member after the torque reaches the set torque value. That is suppressed useless torque wrenching effort after screw tightening completion by setting the torque to a first object.

Further, according to the present invention, when the torque wrench is removed from the screw to be fastened after the screw to be fastened by the torque wrench, the over-torque absorbing mechanism provided in the torque wrench has the following effect. It is a second object of the present invention to improve the operability of the continuous screw tightening operation of a large number of screws to be fastened by automatically restoring to the position where the tightening operation is possible.

[0006]

In order to achieve the first object, according to the first aspect of the present invention, the torque wrench handle member is formed inside the cylindrical torque wrench handle member. A slide piece urged in the direction of the tip of the torque wrench handle member under the elastic pressure of the provided spring, and an end of the slide piece opposite to the spring contact side end via a support pin. A toggle roller which is rotatably supported by a shaft and a head member which is rotatably supported at the tip of the torque wrench handle member via a head pin which is supported in parallel with the support pin. The head member has an arc-shaped curved concave portion in which a part of the toggle roller is elastically fitted by an elastic force of the spring at an edge of the end portion of the head pin supporting side, and is continuous with the curved concave portion. And the above head A toggle roller guide surface radius is formed along the vortex curve becomes gradually large pins as a base point,
A handle member rotation inhibiting projection is formed at the end of the toggle roller guide surface to inhibit play rotation of the torque wrench handle member, and is fastened to an end opposite to the head pin shaft support end. It is a torque wrench formed with an engagement portion with a screw.

According to a second aspect of the present invention, in addition to the first aspect, a torque wrench in which a toggle roller guide surface formed continuously at an end of the curved recess is formed symmetrically with respect to the curved recess. It is characterized by being.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on an embodiment shown in the drawings.

Reference numeral 1 denotes a torque wrench handle member formed in a cylindrical shape. A notch 2 is formed at the tip of the torque wrench handle member 1 along the axial direction of the torque wrench handle member 1.
A pair of support pieces 3A and 3B are formed, and a slide piece 4 slidably held on the inner surface of the torque wrench handle 1 and the slide piece 4 inside the torque wrench handle 1. A spring 5 for pushing the piece 4 toward the tip of the torque wrench handle 1 is provided.

A torque setting means including a thrust ring 6 and a thrust ring center member 7, which are well known as a preset torque wrench, is provided at the rear end of the torque wrench handle 1. By adjusting the position of the thrust ring 6 of the means, the elastic pressure (set torque value) of the spring 5 acting on the slide piece 4 can be adjusted. 8 is a cap attached to the rear end opening of the torque wrench handle 1, and 9 is a thrust ring 6.
The reference numeral 10 indicates a spring tray.

As shown in FIG. 3, the detailed structure of the slide piece 4 is hollow, and a notch 11 is formed at one end thereof along the axial direction of the slide piece 4. A support pin insertion hole 13 is formed in both opposing walls 12A and 12B separated by the notch 11. Further, a guide groove 14 is formed in the outer generatrix direction of the slide piece 4, and a guide piece 15 fixed inside the torque wrench handle 1 is fitted into the guide groove 14. The slide piece 4 is mounted inside the torque wrench handle member 1 so as to be slidable only in the axial direction without rotating in the circumferential direction.

Further, a plurality of oil grooves 16 are formed on the outer periphery of the slide piece 4, and the oil injected into these oil grooves 16 reduces the friction between the inner surface of the torque wrench handle member 1 and the slide piece 4. The sliding movement of the slide piece 4 is smoothed. The other end of the slide piece 4 has a spring engaging step 1 for engaging and holding the spring 5.
7 are formed.

Reference numeral 18 denotes a toggle roller located in the notch 11 formed in the slide piece 4. The toggle roller 18 has two opposing sides formed on the slide piece 4 via support pins 19. It is rotatably supported by walls 12A and 12B.

Reference numeral 20 denotes a head pin which is supported by a pair of support pieces 3A, 3B formed at the tip of the torque wrench handle 1. The head pin 20 has a rear end of a head member 21. It is pivotally supported.
The head member 21 has a screw 22
Is formed with the engaging portion 23 to be engaged with the second member. The engaging portion 23 may have a wrench shape as shown, or may have a socket shape.

An arcuate curved concave portion 24 into which a part of the toggle roller 18 is fitted is formed at the rear end edge of the head member 21, and the elastic pressure of the spring 5 is formed in the curved concave portion 24. When the receiving toggle roller 18 is elastically fitted, the head member 21 is positioned so as not to swing around the head pin 20 as a fulcrum.

A toggle roller guide surface 25 continuous from one end of the curved concave portion 24 is formed at the rear end edge of the head member 21. The shape of the toggle roller guide surface 25 is the same as that of the curved concave portion 24. And a toggle roller guide surface 25 is formed along a vortex curve having a radius gradually increasing from the head pin 20 as a base point.
Further, at the tip of the toggle roller guide surface 25, a handle member rotation inhibiting projection 27 for suppressing play rotation of the torque wrench handle member 1 is formed. In addition, the curved concave portion 2
4 has a stopper surface 2 for increasing the depth of the curved concave portion and enlarging the contact surface with the toggle roller 18.
6 is extended.

The operation of the present embodiment has been described above. Next, the operation will be described. The head member 21 rotatably pivotally connected to the distal end of the torque wrench handle member 1 via the head pin 20 is provided. A part of the toggle roller 18 is fitted into a curved concave portion 24 formed on the rear end edge of the head member 21. Further, the toggle roller 18 receives the elastic pressure of the spring 5 and presses the elastic member into the curved concave portion 24. The head member 21 is positioned without being rotated about the head pin 20, so that the axis of the head member 21 and the axis of the torque wrench handle member are integrated. .

Therefore, when a screw tightening operation is performed using the torque wrench, the screw 22 to be fastened is engaged with the engaging portion 23 formed on the head member 21 and the torque wrench handle member 1 is moved to the position shown in FIG. By rotating in the direction of the arrow (A), the fastening operation of the screw to be fastened 22 proceeds. When the fastening torque reaches a set torque value set by the adjusting elastic pressure of the spring 5, the rotating power of the torque wrench handle member 1 exceeds the elastic force of the spring 5, so that the toggle roller 18 causes the head member 21 to bend. The toggle roller 18 is separated from the concave portion 24 and further guided by the toggle roller guide surface 25, and the torque wrench handle member 1 is rotated (idle) in the arrow direction about the head member 21 with the head pin 20 as an axis. Therefore, when the screw tightening torque value exceeds the set torque value by the spring 5 during the screw fastening operation using the torque wrench, the torque wrench handle member 1 is immediately idled around the head pin 20 and the torque wrench handle member is rotated. Since one rotation power is absorbed, an overtorque effect on the screw to be fastened can be effectively prevented.

Thus, when the toggle roller 18 rolls along the toggle roller guide surface 25, the toggle roller guide surface 25 has a vortex curve whose radial distance from the head pin 20 gradually increases along the rolling direction of the toggle roller 18. The rolling load rolling along the torque roller guide surface 25 is gradually increased. Accordingly, the screw is tightened at the set torque value by the torque wrench, and the load of the torque wrench handle 1 in the A direction after the toggle roller 18 is pushed up from the curved recess 24 gradually increases, and the inertia of the torque wrench handle 1 ( The rotational force due to inertia gradually decreases. When the inertia of the torque wrench handle member 1 is reduced, the hand or arm of the screw tightening operator using the torque wrench may be impacted against another object by the inertia at the time of screw tightening, resulting in injury. It is possible to prevent accidents such as accidents.

As described above, after the inertia of the torque wrench handle member 1 during the screw tightening operation is absorbed by the shape of the toggle roller guide surface, the toggle roller 18 comes into contact with the handle member rotation inhibiting projection 27. Then, since the rotation of the torque wrench handle member 1 is stopped in a rotation range of about 90 degrees from the initial position, an extra free rotation of the torque wrench handle member 1 is suppressed. Consumption of unnecessary labor (rotational energy) can be suppressed.

After the fastening of the screw 22 to be fastened is completed, the head member 21 is detached from the screw 22 to be fastened.
A restoring force due to the elastic force of the toggle roller 18 acts on the head member 21 receiving the elastic pressure of the toggle member 18, and as a result, the head member 21 is restored, and the toggle roller 18 is placed in the curved concave portion 24 formed in the head member 21. Is automatically returned to the initial state of use of the torque wrench, and the next thread to be fastened is ready for fastening.

In the torque wrench shown in the above embodiment, a stopper surface 26 is formed on the rear end face of the head member 21 so as to be continuous with the curved concave portion 24. The rotation escape direction is set to only the direction A in FIG. 1 and is not rotated in the direction opposite to the direction A. Therefore, in order to perform the set torque tightening of the screw 22 to be fastened, FIG. In the direction of the head member 21 shown, the set torque of the right screw 23 can be tightened.
Further, by setting the direction of the head member 21 to the reverse direction in FIG. 1, the set torque of the left screw 23 can be tightened. In FIG. 1, if the torque wrench handle member 1 is rotated in the direction opposite to the arrow direction (A), the screw 23 (right-hand screw) can be loosened by the locking action between the toggle roller 18 and the stopper surface 26. .

In the embodiment shown in FIG.
1 illustrates a head member 21 in which a spiral roller guide surface 25 at a rear end edge of the head member 1 is formed symmetrically with respect to a curved concave portion 24. By using the head member 21 having such a symmetrical toggle roller guide surface 25, both the right-hand screw and the left-hand screw can be freely screwed without changing the direction of the front and back of the head member 21. can do.

[0024]

As described above, according to the torque wrench of the present invention, at the time of fastening operation of the screw to be fastened, the handle member of the torque wrench is bent against the head member at the same time as the fastening torque reaches the set torque. As a result, the fastening torque acting on the torque wrench handle member is directly absorbed, so that no over-torque is generated for the screw to be fastened.

According to the torque wrench of the present invention, the head member 21 is formed so as to follow a vortex curve in which the radial distance from the head pin gradually increases along the rolling direction of the toggle roller. After the toggle roller is pushed up from the curved concave portion, the torque wrench handle member gradually increases the A-direction turning load, and the torque wrench handle member has inertia (inertia).
Since the rotational force caused by the gradual decline gradually, the hand or arm of the screw tightening worker using the torque wrench may hit the other object by the inertia at the time of screw tightening and cause an accident such as injury. Can be prevented.

After the inertia of the torque wrench handle is absorbed by the toggle roller guide surface shape, the toggle roller comes into contact with the handle rotation inhibiting protrusion, and the rotation of the torque wrench handle starts at the initial position. Since the rotation is stopped in a rotation range of about 90 degrees from the above, consumption of useless labor (rotation energy) at the time of operating the torque wrench can be suppressed.

The head member, which has been bent by about 90 degrees with respect to the torque wrench handle member after the completion of the screw fastening with the set torque of the screw to be fastened, is separated from the fastening screw by separating the head member from the fastening screw. In order to automatically restore and return to the initial position before the screw fastening work so that the axis of the member and the axis of the torque wrench handle member coincide, especially a large number of fastened screws must be continuously fastened. This has the effect of improving workability and quickness in the screw fastening operation when it must be performed.

[Brief description of the drawings]

FIG. 1 is a plan sectional view showing an embodiment of a torque wrench according to the present invention.

FIG. 2 is a side view showing an embodiment of the torque wrench according to the present invention.

3A and 3B show a slide piece used in the torque wrench of the present invention, wherein FIG. 3A is a left side view, FIG. 3B is a sectional view taken along line YY in FIG. 3A, and FIG. XX in the figure
Line sectional view.

FIG. 4 is a plan view showing another embodiment of the head member used for the torque wrench according to the present invention.

FIG. 5 is an explanatory diagram showing general torque characteristics at the time of a screw tightening operation using a torque wrench.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Torque wrench handle member 2 ... Cut 3A, 3B ... Support piece 4 ... Slide piece 5 ... Spring 6 ... Thrust ring 7 ... Thrust ring center member 8 ... Cap 9 ... Locating screw 10 ... Spring receiving tray 11 ... Notch 12A, 12B: Opposing wall 13: Support pin insertion hole 14: Guide groove 14: Guide piece 16: Oil groove 17: Spring engaging step 18: Toggle roller 19: Support pin 20: Head pin 21: Head member 22: Fastened screw 23 Engaging portion 24: Curved concave portion 25: Toggle roller guide surface 26: Stopper surface 27: Handle rotation inhibiting protrusion

Claims (2)

[Claims] 1. A torque wrench handle member is biased toward the distal end of a torque wrench handle member within a cylindrical torque wrench handle member under the elastic pressure of a spring provided inside the torque wrench handle member. A slide piece, a toggle roller rotatably supported via a support pin at an end opposite to the spring contact side end of the slide piece, and a tip end of the torque wrench handle member. A head member that is pivotally supported via a head pin that is supported in parallel with the support pin, and the head member includes an end edge of the head pin supporting side, and An arcuate curved concave portion, part of which is elastically fitted by the elastic force of the spring, and a toggle rod formed along the vortex curve continuous with the curved concave portion and having a radius gradually increasing from the head pin as a base point. A guide member formed at the end of the roller guide surface and the toggle roller guide surface to prevent play of the torque wrench handle member, and an end opposite to the head pin shaft support end. A torque wrench characterized by forming an engagement portion with a screw to be fastened. 2. The torque wrench according to claim 1, wherein the toggle roller guide surface formed continuously with the curved concave portion of the head member is formed symmetrically with respect to the curved concave portion.