JP2001232575A - Open end wrench - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an open end wrench rotating a shaftlike workpiece by gripping a tool engaging part C3 having a hexagonal cross section of the workpiece, supporting a pair of first and second rotary bodies having an insertion groove allowing the tool engaging part C3 to be inserted in the radial direction on a wrench main body, gripping the tool engaging part C3 by a clamp member to rotate the workpiece, and gripping the tool engaging part coaxially with both rotary bodies to rotate the workpiece smoothly. SOLUTION: When a clamp arm swings to a clamp position on an inner side in the direction of groove width, contact sides 36b, 36b for the tool engaging part of clamp arms 36, 36 coincide with a predetermined chord which is inclined inward in the direction of groove width toward an opening end side of the insertion groove 31b for a central line T of the insertion groove 31b and in which a distance L1 between crossing points on the opening end side of the insertion groove 31b of a circle S and both chords is larger than a distance L2 between opposite sides of the tool engaging part C3 among the chords on both sides in the direction of groove width of the insertion groove 31b in the circle S which has equal diameter to a circumscribed circle and is concentric with an axial line.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an open-end wrench used for engaging a hexagonal tool engaging portion of a shaft-shaped work such as a tie rod incorporated in a steering mechanism of an automobile to rotate the work forward and backward.

[0002]

2. Description of the Related Art FIG.
As shown in the figure, a tie rod C for transmitting the movement of the relay rod A linked to the handle to the knuckle arm B is incorporated. The tie rod C includes a rod body C1 connected to the relay rod A via a ball joint A1, and a rod end C2 connected to the knuckle arm B via a ball joint B1. Rod body C
One end of the tie rod C is screwed into the rod end C2, and the length of the tie rod C is reduced by rotating the rod body C1 by engaging a wrench with a tool engaging portion C3 having a hexagonal cross section formed on the rod body C1. To adjust the wheel toe. After the toe adjustment, the rod body C
The nut C4 extrapolated to 1 is fastened to the rod end C2 side to prevent the rod body C1 from rotating.

[0003] By the way, depending on the type of vehicle, the tie rod C
Is placed in a complicated place, and there is a case where the operation space of the wrench cannot be secured. Therefore, an open-end wrench is known from Japanese Patent Application Laid-Open No. 1-295766 in which a tie rod can be rotated forward and backward while holding the wrench in a fixed position. This open-end wrench is a first wrench capable of radially inserting a tool engagement portion at a tip end of a wrench body.
And a second pair of rotating bodies are rotatably supported around the same axis, and one of the two rotating bodies, for example, the second rotating body, is provided at three locations around the tool engagement portion C3 as shown in FIG. 3 that can contact
While supporting the rollers a so as to be movable in the radial direction,
Three pairs of cam surfaces c that are in contact with these rollers a are formed on the inner periphery of the first rotator b, and the first rotator b is rotated forward or backward by the driving means while the second rotator is braked by the brake means. When this is done, the three rollers a are configured to be pushed radially inward by the respective cam surfaces c to abut on the tool engaging portion C3. When the roller a comes into contact with the tool engaging portion C3, the second rotating body rotates integrally with the first rotating body b against the braking force of the brake means, and the tie rod moves in the same direction as the first rotating body b. Rotated.

[0004]

In the above open-end wrench, if the three pairs of cam surfaces c are not formed jointly with a phase difference of 120 °, the tool engaging portion C3 is misaligned with respect to the rotating body. And the tie rod cannot be rotated properly. Therefore, the allowable range of the dimensional tolerance of the three pairs of cam surfaces c is narrowed, and high-precision machining of the cam surfaces c is required, and the cost is increased.

[0005] In view of the above, an object of the present invention is to provide a low-cost open-end wrench capable of holding a tool engaging portion concentrically with a rotating body.

[0006]

Means for Solving the Problems In order to solve the above problems,
The present invention relates to an open-end wrench used to engage a tool engagement portion having a hexagonal cross section of a shaft-shaped work to rotate the work forward / reversely, and rotatably supports the front end of the wrench body around the same axis. A first and a second pair of rotating bodies having an insertion groove in which the tool engaging portion can be inserted in the radial direction, and a first rotating body positioned on both sides of the insertion groove of the first rotating body, A pair of clamp arms pivotally supported in the groove width direction of the insertion groove and a pair of clamp arms, and when the first rotator is rotated forward and reverse with respect to the second rotator from a phase where the insertion grooves of both rotators match. A cam mechanism for swinging both clamp arms to a predetermined clamp position inward in the groove width direction, a driving means for rotating the first rotating body in the normal and reverse directions, and a braking means for braking the second rotating body; At the bottom of the body insertion groove or at the tip of the wrench body, insert the tool engagement A work guide having an insertion groove that can be inserted is fixed, and the bottom of the insertion groove of the work guide is formed in a semicircle having the same diameter as the circumscribed circle of the cross-sectional shape of the tool engagement portion and concentric with the axis, In the clamp position, the both sides of the insertion groove of the first rotating body in the circle having the same diameter as the circumscribed circle and concentric with the axis at the abutting sides of the two clamp arms at the clamp position. Among the chords, inclined inward in the groove width direction of the insertion groove toward the opening end side of the insertion groove with respect to the center line of the insertion groove, and the opening of the insertion groove between the circle and both strings It is formed so that the distance between the intersections on the end side matches a predetermined chord that is larger than the distance between the opposite sides of the cross-sectional shape of the tool engagement portion.

When rotating the work, the first and second rotators are set in phase so that the insertion grooves of the two rotators match each other and also match the insertion grooves of the work guide. The tool engaging portion of the work is inserted into the insertion groove, and then the first rotating body is rotated in the forward or reverse direction by the driving means while the second rotating body is braked by the brake means. According to this, both clamp arms are swung to the clamp position by the action of the cam mechanism. However, at the clamp position, the contact sides of both clamp arms coincide with the above-mentioned predetermined chords. As described in, before the contact side of the clamp arm at the front position in the rotation direction of the first rotating body contacts the tool engagement portion, the contact side of the clamp arm at the rear position in the rotation direction is the second rotation body or The work guide comes into contact with the corner of the tool engaging portion projecting from the semicircular bottom of the insertion groove to the opening end side of the insertion groove, and the tool engaging portion is pressed against the semicircular bottom of the insertion groove and It is centered concentrically with the rotating body. Here, even if the clamp position of the clamp arm at the front in the rotation direction is slightly displaced inward from the normal position in the groove width direction, the clamp arm at the rear in the rotation direction contacts the tool engagement portion earlier. Thus, even if the accuracy of the cam mechanism is rough, the tool engagement portion can be gripped concentrically with both rotating bodies.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to an open-end wrench for adjusting a tie rod will be described below. As shown in FIGS. 1 to 3, this open-end wrench engages with a nut rotating part 2 for rotating a lock nut C4 of a tie rod C and a tool engaging part C3 of a tie rod C at the tip of a wrench body 1. And a rod rotator 3 for rotating the rod body C1 forward and backward.

The nut rotating part 2 is a movable casing 2 supported on the wrench body 1 so as to be movable in the axial direction of the tie rod C.
The rotating body 21 is supported at 0. The rotator 21 is provided on both sides of the movable casing 20 in the axial direction.
a, and concentric circular holes 20b, 20b are formed in both side plate portions 20a, 20a.
b, the shaft portions 21a projecting from both sides in the axial direction of the rotating body 21 are fitted to each other, and the rotating body 21 is made to have an axis O concentric with the circular hole 20b.
It is rotatably supported around.

The movable casing 20 has respective side plates 20a.
A notch 20c for inserting the rod end C2 is formed at the tip of the rod so as to reach the circular hole 20b.
In addition, as shown in FIG.
Two insertion grooves 21b are formed. Thus, the rotating body 2
If 1 is set to the phase in which the insertion groove 21b matches the notch 20c, the rod end C2 can be radially inserted into the insertion groove 21b through the notch 20c. In addition, the movable casing 20
A plate-shaped work guide 22 is screwed to the outer side surface of the side plate portion 20a on the outside in the axial direction. The bottom of the insertion groove 22a is formed in a semicircle having the same diameter as the outer diameter of the rod end C2 and concentric with the center of the circular hole 20b as the rotation axis of the rotating body 21, and the rod end C2 is formed as a half of the insertion groove 22a. By pushing the rod end C2 into the circular bottom, the rod end C2 is centered concentrically with the rotating body 21.

The rotating body 21 is provided with a socket 21c into which a lock nut C4 can be inserted in the axial direction. Then, a plurality of pieces 21d that can be engaged with the lock nut C4 are mounted in the socket portion 21c, and the lock nut C4 can be rotated by the rotation of the rotating body 21. here,
The rotating body 21 is rotationally driven in both forward and reverse directions by a driving unit 23. The driving means 23 includes a nut runner 230 as a driving source mounted on a base end portion of the wrench main body 1 and a drive gear which is supported via a chain 231 by the nut runner 230 pivotally supported near the movable casing 20 of the wrench main body 1. 232 and the teeth 2 formed on the outer periphery of the rotating body 21
1e which is pivotally supported by the movable casing 20 so as to mesh with 1e.
A pair of driven gears 233 and 233 and a drive gear 23
The first and second intermediate gears 234 and 235 are supported by the movable casing 20 so as to connect the second gear 2 and the driven gears 233 and 233.

A bracket 10 is mounted on the wrench main body 1 so as to be located axially outside the nut rotating section 2.
A pair of support shafts 1 for the driven gears 233 and 233 are provided between the bracket 10 and a fixed casing 30 described later.
1, 11 and the support shaft 12 for the first intermediate gear 234 are provided sideways through the movable casing 20, and these support shafts 11, 1
The movable casing 20 is supported movably in the axial direction via the first and second movable casings 1 and 12. Then, the cylinder 24 is attached to the axially outer side plate portion 20a of the movable casing 20, and the piston rod 24a of the cylinder 24 is
The intermediate gear 235 is also connected to the fixed casing 30 while also serving as a support shaft. Thus, the movable casing 20 is advanced and retracted in the axial direction toward the lock nut C4 by the cylinder 24, and the socket portion 21c can be engaged and disengaged from the lock nut C4 by this advance and retreat operation. The drive gear 232 is formed longitudinally in the axial direction so that the first intermediate gear 234 does not separate from the drive gear 232 even when the movable casing 20 moves in the axial direction.

The rod rotating section 3 includes a first and a second pair of rotating bodies 31 and 32 which are supported by a fixed casing 30 fixed to the wrench body 1. Both rotating bodies 31, 32
As shown in FIGS. 1 and 7, the side plates 30 a, 30 a on both sides in the axial direction of the fixed casing 30 are fitted together.
It is sandwiched between. And both side plate parts 30a, 30
a, circular holes 30b, 30b concentric with the circular holes 20b of the movable casing 20 are formed.
Shafts 31a and 32a protruding from the axially outer surfaces of the shafts 1 and 32
And the two rotating bodies 31 and 32 are rotatably supported around the same axis O as the rotating axis of the rotating body 21 of the nut rotating unit 2.

Each side plate 30 of the fixed casing 30
A notch 30c for insertion of the tool engaging portion C3 of the tie rod C, which is a shaft-shaped work, is formed at the tip end of "a" so as to reach the circular hole 30b, and both rotating bodies 31, 32 are shown in FIGS. As described above, the insertion grooves 31b and 32b for the tool engagement portion C3 that are opened on the outer peripheral surface are formed. Thus, if the two rotating bodies 31, 32 are set to the phase (the origin phase) where the insertion grooves 31b, 32b coincide with the notch 30c, the insertion grooves 31b, 32
The tool engagement portion C3 can be inserted in the radial direction b through the notch 30c. Further, a plate-shaped work guide 33 is screwed to the outer side surface of the axially outer side plate portion 30a of the fixed casing 30, and the work guide 33 is also provided with an insertion groove 33a in which the tool engagement portion C3 can be radially inserted. Has formed. And
The bottom of the insertion groove 33a is formed in a semicircle having the same diameter as the circumscribed circle of the sectional shape of the tool engaging portion C3 and concentric with the axis O,
By pushing the tool engaging portion C3 into the semicircular bottom of the insertion groove 33a, the tool engaging portion C3 is centered concentrically with the axis O.

The first rotating body 31 is rotationally driven in both forward and reverse directions by a driving means 34. The driving means 34 includes a servomotor 340 as a driving source mounted on the base end side of the wrench body 1.
And a drive gear 342 supported by a servomotor 340 via a chain 341 and a gear 341a, which is pivotally supported on a portion of the wrench body 1 near the fixed casing 30.
And a pair of driven gears 343 and 343 supported by the fixed casing 30 via the support shafts 11 and 11 so as to mesh with the teeth 31 c formed on the outer periphery of the first rotating body 31, and the drive gear 342 and the driven gear 342. The first and second intermediate gears 344 and 345 are supported by the fixed casing 30 via the support shaft 12 and the piston rod 24a so as to connect the gears 343 and 343, respectively.

The second rotating body 32 is provided with a braking means 35.
It is configured to be able to brake by. The brake means 35 includes a pair of brake shoes 351 and 351 slidably supported via pins 350 in the fixed casing 30 so as to be in contact with and separated from the outer periphery of the second rotating body 32. Wires 352 and 352 to 351 and 351
And a cylinder 353 attached to the wrench body 1. Then, the brake shoe 35 is moved by the cylinder 353 through the wires 352 and 352.
1, 351 to pull the brake shoe 35
1, 351 is pressed against the outer periphery of the second rotating body 32 so that the second rotating body 32 is braked.

The first rotating body 31 is positioned on both sides of the insertion groove 31b formed in the first rotating body 31, and a pair of clamp arms 36, 36 are respectively provided with the pin 36a as a fulcrum. It is provided swingably in the width direction. Then, the first rotator 31 is connected to the two rotators 3 with respect to the second rotator 32.
When the insertion grooves 31b and 32b of the first and second insertion grooves 31b and 32b are rotated forward and backward from the matching reference phase, the two clamp arms 36 and 36 are moved by the cam mechanism 37 from the unclamping position outside the groove width direction to the clamping position inside the groove width direction. To be rocked.

The cam mechanism 37 includes a cam portion 370 formed on the outer edge of each clamp arm 36 and a cam portion 370 fixedly provided in a pair on the second rotating body 32 in correspondence with the clamp arms 36, 36. And a cam pin 371 that abuts. The cam portion 370 has a first arc portion 370a that matches an arc concentric with the axis O in a state where the clamp arm 36 is at the unclamping position, and a radial direction from the first arc portion 370a toward the distal end side of the clamp arm 36. A first oblique portion 370b extending inclining outward and a first oblique portion 370b;
A second arc portion 370c extending from the end to the tip side of the clamp arm 36 and conforming to an arc concentric with the axis O when the clamp arm 36 is at the clamp position;
0a, a second oblique portion 370d extending radially outward from the second oblique portion 370d toward the tail end of the clamp arm 36, and the clamp arm 36 extending from the second oblique portion 370d to the tail end of the clamp arm 36. Axis O
And a third arc portion 370e that matches the concentric arc. The cam pin 371 is provided so as to abut the center of the first arc portion 370a when the phase of the first rotating body 31 with respect to the second rotating body 32 is at the reference position. Thus, when the first rotator 31 is rotated forward / reversely from the reference phase with respect to the second rotator 32, when the first arc portion 370a is rotated by an angle α that is half the central angle of the first arc portion 370a, the first arc portion 370a rotates forward (in the rotation direction The first oblique portion 37 of the clamp arm 36 (the right side in the clockwise direction in FIG. 5 and the left side in the counterclockwise direction).
0b and the second oblique portion 370d of the clamp arm 36 located rearward in the rotation direction abut on the cam pins 371, respectively, and thereafter, the second arc portion 370c of the clamp arm 36 located forward in the rotation direction and the clamp arm 36 located rearward in the rotation direction Of the third arc 370
By rotation until e contacts the cam pin 371, the clamp arms 36 are guided by the oblique portions 370b and 370d, and are swung from the unclamped position to the clamped position.

Each of the clamp arms 36 has a cam 37.
0, a cam groove 372 having a shape similar to that of the first rotary member 32 is formed, and an engaging pin 373 for engaging with the cam groove 372 is fixed to the second rotary member 32. When returning to the reference phase by rotating in the opposite direction, the interaction between the engaging pin 373 and the cam groove 372 causes each clamp arm 36 to return to the unclamped position. In addition, the relative rotation angle range of the first rotating body 31 with respect to the second rotating body 32 is determined by adjusting the engagement pin 3 to the end of the cam groove 372.
The abutment of 73 allows the rotation to be restricted to a range slightly larger than the rotation angle required to swing the clamp arm 36 from the reference phase to the clamp position. FIG. 9 shows the relative rotation angle of the first rotator 31 with respect to the second rotator 32 and the swing angle of the clamp arm 36 in the groove width direction. Within the range of α, the clamp arm 36 is held at the unclamping position, and within the angle range of β exceeding α, the clamp arm 36 is swung from the unclamping position to the clamping position, and the relative rotation is restricted after exceeding β. The clamp arm 36 is held at the clamp position within the angular range of γ until the angle .gamma.

At the clamp position, the abutting sides 36b, 36b of the inner edges of the clamp arms 36, 36 with respect to the tool engaging portion C3 have the cross-sectional shape of the tool engaging portion C3 as shown in FIG. It is formed so as to match two predetermined chords on both sides in the groove width direction of the insertion groove 31b of the first rotating body 31 in a circle S having the same diameter as the circumscribed circle and concentric with the axis O. The two strings are inclined inward in the groove width direction toward the opening end of the insertion groove 31b with respect to the center line T of the insertion groove 31b, and the insertion groove 31b between the circle S and both strings is formed. Is a chord in which the distance L1 between the intersections on the open end side is larger than the distance L2 between the opposite sides of the cross-sectional shape of the tool engagement portion C3. When the contact side 36b is formed in this way, as shown in FIG.
The contact side 36a of the clamp arm 36 (right side in (B))
Is engaged with the corner of the tool engagement portion C3, the clamp arm 3 in the front position in the rotational direction (left side in FIG. 10B).
6, the gap between the contact side 36a and the tool engaging portion C3 is still clear, and the clamping position of the clamp arm 36 at the front position in the rotation direction is changed to the groove due to a machining error of the cam mechanism 37 or the like. Even if the clamp arm 36 is slightly displaced inward in the width direction, the clamp arm 36 located rearward in the rotation direction grips the tool engagement portion C3 ahead of the clamp arm 36 located forward in the rotation direction.

As shown in FIG. 8, each of the driven gears 343 has a piston 11 fixed to a support shaft 11 for supporting the driven gear.
a is provided with a cylinder portion 343a for receiving the a. Then, by supplying air into the cylinder portion 343a from an air joint 11b attached to the end of the support shaft 11 on the bracket 10 side via an air passage 11c in the support shaft 11, the driven gear 343 is driven by the second rotating body. When the air supply is stopped, the return spring 343b retracts toward the position where the first rotating body 31 is disposed when the air supply is stopped. The toothed portion 32c is formed on the outer periphery of the second rotating body 32, and the driven gear 343 is moved forward and backward in the axial direction as described above, so that the driven gear 343 is engaged with and disengaged from the toothed portion 32c. Incidentally, a fan portion 343c is formed at the end of the tooth of the driven gear 343, and even if the phase of the tooth portion 32c of the second rotating body 32 is slightly shifted from the tooth portion 31c of the first rotating body 31. The phase shift is corrected by the chan fan portion 343c so that the driven gear 343 can be engaged with the tooth portion 32c. A laser range finder 38 that detects the position of the driven gear 343 by inputting and reflecting laser light to a reflecting plate 343d mounted on the forward end surface of the driven gear 343 is attached to the fixed casing 30.

In adjusting the toe of the wheel, first, the rotating body 21 of the nut rotating part 2 is set to the original phase in which the insertion groove 21b matches the notch 20c of the movable casing 20, and the first rotating part of the rod rotating part 3 Second rotating bodies 31, 32
At the origin phase where the insertion grooves 31b and 32b of the two 31 and 32 match the notch 30c of the fixed casing 30, and in this state, the rod end C2 of the tie rod C and the tool engagement portion C
3 through each notch 20c, 30c.
31 and 32 are inserted into the insertion grooves 21b, 31b and 32b. At this time, the rod end C2 and the tool engaging portion C3 are also inserted into the insertion grooves 22a and 33a of the work guides 22 and 33 fixed to the movable casing 20 and the fixed casing 30, and the rod end C2 and the tool engaging portion C3 are connected. Insertion groove 22
The entire tie rod C is concentric with the rotation axis O of the rotating bodies 21, 31, 32 by pressing against the semicircular bottom of the a, 33 a.

Next, the movable casing 20 is moved in the axial direction, and the socket 21c of the rotating body 21 is
4 and the lock nut C4 is loosened by the rotation of the rotating body 21. Further, the first rotating body 31 is rotated by the driving means 34 in a required direction, for example, counterclockwise in FIG. 11, while the second rotating body 32 is braked by the brake means 35. According to this, the first rotating body 3 with respect to the second rotating body 32
1 is relatively rotated from the reference phase, and the pair of clamp arms 36, 36 are swung from the unclamped position to the clamped position while revolving around the axis by the operation of the cam mechanism 37.

If the tool engaging portion C3 is in a phase in which any one diagonal of the cross-sectional shape of the tool engaging portion C3 matches the semicircular chord x at the bottom of the insertion groove 33a, FIG.
As shown in (A), the contact side 36 b of the right clamp arm 36, which is the clamp arm rearward in the rotation direction, is inserted into the insertion groove 33.
The upper right corner C3 of the tool engagement portion C3 that has come off the bottom of
a.

If the tool engaging portion C3 is in a phase in which it contacts the bottom of the insertion groove 33a at the three lower corners, before the right clamp arm 36 reaches the clamp position, as shown in FIG. As shown, the contact side 36b of the right clamp arm 36 may contact the right corner C3b of the tool engagement portion C3 that has come off the bottom of the insertion groove 33a. In this case, if the contact side 36b substantially matches the tangent to the circumscribed circle of the cross-sectional shape of the tool engagement portion C3, the contact side 36b slides with respect to the corner C3b. At this time, since the inward swing of the clamp arm 36 in the groove width direction is restricted by the corner portion C3b, the relative rotation of the first rotating body 31 with respect to the second rotating body 32 is interrupted. That is, the second rotating body 32 rotates together with the first rotating body 31 against the braking force of the braking means 35 by the rotating force from the first rotating body 31 transmitted via the cam mechanism 37. Then, when the contact side 36b of the right clamp arm 36 gets over the corner C3b, the relative rotation of the first rotating body 31 with respect to the second rotating body 32 is resumed, and the clamp arm 36 swings to the clamp position. As shown in FIG. 11C, the contact side 36b of the right clamp arm 36 is engaged with the uppermost corner portion C3c of the tool engagement portion C3.

Thus, irrespective of the phase of the tool engaging portion C3, the corner of the tool engaging portion C3 deviating from the bottom of the insertion groove 33a is brought into contact with the clamp arm 36 located rearward in the rotation direction. The contact sides 36b are engaged, and the tool engagement portion C3 is sandwiched between the insertion portion 33a and the bottom of the insertion groove 33a.
It is centered concentrically with the axes O of 1,32. Then, through the clamp arm 36 located rearward in the rotation direction, the tool engagement portion C3
Is prevented from rotating with respect to the first rotating body 31, and thereafter, the rod body C1 is rotated integrally with the first rotating body 31, and the length of the tie rod C is changed by this rotation to adjust the toe.

When the toe adjustment is completed, the lock nut C4 is tightened by the rotation of the rotating body 21 in the nut rotating section 2, and then the movable casing 20 is moved to disengage the rotating body 21 from the lock nut C4. The body 21 is returned to the origin phase. Further, in the rod rotating unit 3, while the second rotating body 32 is being braked by the braking means 35, the first rotating body 31 is driven by the driving means 34 in the opposite direction to the time when the toe adjustment is performed. Rotate for a minute,
Next, in a state where the braking of the second rotating body 32 by the braking means 35 is released, each driven gear 343 is advanced in the axial direction, and each driven gear 34
3 is engaged.

By the way, both the rotating bodies 3 at the time of the toe adjustment are adjusted.
The deviation angle of the reference phase of 1, 32 with respect to the maximum is α + β + γ
Thus, even if the first rotating body 31 is rotated back by the angle of α + β as described above, the first rotating body 3 with respect to the second rotating body 32
The phase of 1 may deviate from the reference phase by γ. In some cases, the clamp arm 36 engages with the tool engagement portion C3 before reaching the clamp position. In this case, when the first rotating body 31 is rotated back by α + β, the first rotating body 31 The phase of the rotator 31 is shifted from the reference phase. Here, the tooth portions 3 of the first and second rotating bodies 31 and 32
Assuming that the pitch angle of 1c and 32c is θ, if the shift angle from the reference phase to the tenth side or one side is smaller than θ / 2, the driven gear 343 is engaged with the tooth portion 32c of the second rotating body 32. , The deviation from the reference phase can be eliminated.
On the other hand, if the deviation angle from the reference phase is larger than θ / 2,
By engaging the driven gear 343 with the tooth portion 32c,
The deviation angle from the reference phase becomes θ. However, the clamp arm 36 is held at the unclamping position when the deviation angle with respect to the reference phase is equal to or less than α, so that even when the deviation angle becomes θ, the clamp arm 36 does not swing leftward from the unclamping position. In the present embodiment, α, β, γ, and θ are set to 10 °, 11 °, 3 °, and 12 °, respectively.
Of the insertion groove 31b.

When the engagement of the driven gear 343 with the tooth portion 32c of the second rotating body 32 is confirmed by a signal from the laser range finder 38, the first rotating body 31 is rotated by the driving means 34 next. To return to the origin phase. Next, the driven gear 343
The wrench body 1 is pulled back in the direction opposite to the opening direction of the notches 20c, 30c, and the open-end wrench is separated from the tie rod C. Here, the first rotating body 31
When returning to the origin phase, the second rotating body 32 is also integrally rotated via the driven gear 343, so that the first rotating body 31
Arm 3 due to the phase shift of second rotating body 32 with respect to
6 can be reliably prevented from protruding into the groove width of the insertion groove 31b. Therefore, the open-end wrench can be smoothly removed from the tie rod C without causing the clamp arm 36 to be hooked on the tool engagement portion C3. Further, even when the phase of the second rotating body 32 is shifted from the reference phase by θ with respect to the first rotating body 31, when the open-end wrench is separated from the tie rod C, the side edge of the insertion groove 32b of the second rotating body 32 is formed. The tool engaging portion C3 slides and the deviation of the second rotating body 32 from the reference phase is corrected, so that the detaching operation of the open-end wrench can be performed without any trouble.

In the above embodiment, the bottoms of the insertion grooves 31b and 32b of the first and second rotating bodies 31 and 32 are formed in a semicircle having a diameter larger than the circumscribed circle of the cross-sectional shape of the tool engagement portion C3. However, even if the bottom of the insertion groove 32b of the second rotating body 32 is formed in a semicircle having the same diameter as the circumscribed circle and concentric with the axis O, the clamp arm 36 located rearward in the rotation direction can be used as a tool holder. The joint portion C3 can be gripped concentrically with the axis O while being sandwiched between the joint portion C3 and the bottom of the insertion groove 32b. In this case, work guide 3
3 is unnecessary.

[0031]

As is apparent from the above description, according to the present invention, even if the accuracy of the cam mechanism is rough, the tool engaging portion is gripped concentrically with the axes of the two rotating bodies, and the workpiece is held. Rotation can be performed smoothly, and the cost can be reduced as compared with a conventional open-end wrench that requires high-precision machining of three pairs of cam surfaces.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of the open-end wrench of the present invention.

FIG. 2 is a left side view of FIG. 1;

FIG. 3 is a right side view of FIG. 1;

FIG. 4 is an enlarged sectional view taken along the line IV-IV of FIG. 1;

FIG. 5 is an enlarged sectional view taken along line VV of FIG. 1;

FIG. 6 is an enlarged sectional view taken along the line VI-VI of FIG. 1;

FIG. 7 is a sectional view taken along the line VII-VII of FIG. 5;

8 is a sectional view taken along line VIII-VIII in FIG.

FIG. 9 is a graph showing the relationship between the relative rotation angle of the first and second rotating bodies and the swing angle of the clamp arm.

10A is a diagram illustrating a position of a contact side when a clamp arm is swung to a clamp position, and FIG. 10B is a diagram illustrating an engagement state of the contact side with a tool engagement portion.

FIG. 11A is a diagram showing a gripping state of a tool engagement portion.
(B) A diagram showing an intermediate state before gripping a tool engaging portion existing in a different phase from FIG. 10 (A), and (C) a diagram showing a gripping state of the tool engaging portion.

FIG. 12 is a perspective view of a tie rod.

FIG. 13 is a side view of a main part of a conventional open-end wrench.

[Explanation of symbols]

C Tie rod (work) C3 Tool engaging part 1 Wrench main body 30 Fixed casing (tip of wrench main body) 31 First rotating body 32 Second rotating body 33 Work guide 31b, 32b, 33a
Insertion groove 34 Drive means 35 Brake means 36 Clamp arm 36b Contact side

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Atsushi Nagata 1-10-1 Shinsayama, Sayama-shi, Saitama Honda Engineering Co., Ltd. F-term (reference) 3C038 AA01 AA03 AA04 AA06 BB03 BB08 BC04 DA02 EA01 EA03 EA06

Claims (2)

[Claims] An open-end wrench for engaging a hexagonal cross-section tool engaging portion of a shaft-shaped work to rotate the work forward and reverse, wherein the tool engaging portion fixed to a tip end of a wrench body has a diameter. A first and a second work guide having an insertion groove which can be inserted in the same direction, and an insertion groove which is rotatably supported on the tip end of the wrench main body so as to be rotatable around the same axis and which can radially insert a tool engagement portion. A pair of rotating bodies, and a pair of clamp arms which are positioned on both sides of the insertion groove of the first rotating body and are pivotally supported in the groove width direction of the insertion groove. A cam mechanism for swinging both clamp arms to a predetermined clamp position inward in the groove width direction when the first rotary body is rotated forward and reverse with respect to the second rotary body from a phase in which the insertion grooves of both rotary bodies match. A driving unit for rotating the first rotating body in the normal and reverse directions, and a brake for braking the second rotating body. Rake means, and the bottom of the insertion groove of the work guide is formed in a semicircle having the same diameter as the circumscribed circle of the cross-sectional shape of the tool engaging portion and concentric with the axis, and both clamp arms at the clamp position. The abutment side of the two clamp arms with respect to the tool engagement portion has the same diameter as the circumscribed circle and is concentric with the axis. The distance between the intersection of the circle and both chords on the opening end side of the insertion groove is a tool that is inclined inward in the groove width direction of the insertion groove toward the opening end side of the insertion groove with respect to the center line. An open-end wrench characterized by being formed so as to match a predetermined chord larger than a distance between opposite sides of a cross-sectional shape of the engaging portion. 2. An open-end wrench used for engaging a hexagonal cross-section tool engaging portion of a shaft-shaped work to rotate the work in a normal / reverse direction, wherein an end of the wrench body is rotatably supported around the same axis. A first and a second pair of rotating bodies having an insertion groove into which the tool engaging portion can be inserted in the radial direction, and a first rotating body positioned on both sides of the insertion groove of the first rotating body. A pair of clamp arms pivotally supported in the groove width direction of the insertion groove, and when the first rotator is rotated forward and reverse from the phase where the insertion grooves of both rotators match with respect to the second rotator. A cam mechanism for swinging both clamp arms to a predetermined clamp position inward in the groove width direction, a driving means for rotating the first rotating body in the normal and reverse directions, and a braking means for controlling the second rotating body. The bottom of the insertion groove of the rotating body has the same diameter as the circumscribed circle of the cross-sectional shape of the tool engagement portion. The two clamp arms are formed in a semicircle concentric with the line, and at the clamping position, the contact sides of the two clamp arms with respect to the tool engagement portion have the same diameter as the circumscribed circle and are concentric with the axis. Of the chords on both sides in the groove width direction of the insertion groove of one rotating body, the string is inclined inward in the groove width direction of the insertion groove toward the opening end side of the insertion groove with respect to the center line of the insertion groove, and The distance between the intersection of the circular groove and both chords on the opening end side of the insertion groove is formed so as to match a predetermined chord that is larger than the distance between the opposite sides of the cross-sectional shape of the tool engaging portion. Open-end wrench.