JPH0735691Y2 - Holding device for crankshaft machining - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a holding device for machining a crankshaft.

[Prior Art] A crankshaft machining holding device capable of holding the crankshaft rotatably around the axis of the crankpin in order to perform various machining on the crankpin has been conventionally known (for example, (See Japanese Laid-Open Patent Publication No. 62-147401).

Such a conventional crankshaft machining holding device is
For example, as shown in FIG. 3, after supporting the crankshaft 101 at both ends and fixing the crankshaft 101 in an appropriate phase, a substantially uniform gripping force can be applied by a floating cam (not shown). Became the first
The floating chuck unit 105 provided with the third clamp claws 102, 103, 104 chucks the journal portion 106. The crankshaft 101 thus chucked can be freely rotated by a rotating means (not shown) around the axis of the crankpin 107 to be processed.

The phase of the crankshaft 101 is fixed by sandwiching the locking member 108, the pressing member 109 and the crank arm 111 prior to chucking. Here, in order to interlock the phase fixing operation by the pressing member 109 with the forward / backward movement of the first to third clamp claws 102 to 104, the first clamp claw 102 and the pressing member 109 are connected and integrated by the connecting portion 112. Has been done. And the first clamp claw
When 102 advances toward the crankshaft 101 and approaches the journal portion 106, the contact portion 113 of the pressing member 109 contacts the crank arm 111 and locks before the first clamp claw 102 contacts the journal portion 106. Member 108 and pressing member 109
By sandwiching the crank arm 111 between it and the (abutment portion 113), the crankshaft 101 is fixed in a predetermined phase. When the first clamp claw 102 further advances after the abutting portion 113 abuts on the crank arm 111, the abutting portion 113 is pushed into the housing 115 against the biasing force of the spring 114, and the crank arm 111 moves. It is sandwiched between the locking member 108 and the pressing member 1089 (contact portion 113) with an appropriate pressing force according to the biasing force of the spring 114.

[Problems to be Solved by the Invention] However, in the crankshaft machining holding device as shown in FIG. 3, when the first to third clamp claws 102 to 104 chuck the crankshaft 101, the pressing device is pressed. Since the member 109 is pressing the crank arm 111,
As a reaction, the pressing member 109 is pushed from the crank arm 111.
The reaction force acting on the first clamp claw 102 via the connecting portion 112.
The gripping force of the first clamp claw 102 is not equal to the gripping force of the second and third clamp claws 103, 104, and the crankshaft 101 cannot be held with an even gripping force. Therefore, the chucking position of the crankshaft 101 is deviated (so-called chuck misalignment), and when the crankshaft 101 is rotated about the axis of the crankpin 107 to be processed, rotational deviation occurs and 107
However, there is a problem in that the processing accuracy of is reduced.

The present invention has been made in view of the above-mentioned conventional problems, and the gripping force of each clamp claw during chucking can be equalized to hold the crankshaft at an appropriate chucking position. It is an object of the present invention to provide a crankshaft machining holding device having a simple and compact structure capable of improving machining accuracy.

[Means for Solving the Problems] In order to achieve the above object, the present invention engages with a center hole formed in an end portion of a crankshaft to rotatably support the crankshaft around the axis of its journal portion. A center support member, a phase fixing means for fixing the crankshaft supported by the center support member to a predetermined phase by sandwiching the crankshaft with a locking member and a pressing member, and a crankshaft whose phase is fixed by the phase fixing means. In a crankshaft machining holding device provided with a floating chuck unit for chucking the chuck with a plurality of clamp claws, and rotating means for rotating the chucked crankshaft around the axis of the crankpin on which the machining is performed. A spring that biases the member in a certain direction and a predetermined one When the clamp claw retracts from the crankshaft, the clamp claw and the pressing member are engaged so that the pressing member is displaced in the direction opposite to the spring urging direction against the urging force of the spring. An engaging arm that disengages the clamp claw from the pressing member when the clamp claw approaches the crankshaft when advancing toward the crankshaft, and the pressing member is displaced in the urging direction by a spring. Sometimes the pressing member is displaced toward the crankshaft to lock the phase of the crankshaft, while when the pressing member is displaced in the direction opposite to the spring biasing direction, the pressing member is displaced away from the crankshaft. To release the crankshaft phase lock. Providing a holding device for processing crankshafts, wherein a and direction changing member provided.

According to the present invention, when the clamp claw is at the most retracted position (unchucked state) with respect to the crankshaft,
A predetermined one clamp claw (hereinafter, referred to as a first clamp claw) biases the pressing member via the engaging arm in the direction opposite to the direction in which the biasing force of the spring acts, thereby displacing it. The pressing member is separated from the crankshaft by the moving direction changing member. At this time,
The first clamp claw and the pressing member are mechanically engaged with each other via the engaging arm, and the urging force of the spring is transmitted to the clamp claw via the pressing member and the engaging arm.
The clamp claw is pressed in the forward direction.

In order to chuck the crankshaft, when the first clamp claw advances from this state toward the crankshaft in this state, the pressing member is displaced in the urging direction by the urging force of the spring by an amount corresponding to the advance distance. Therefore, the pressing member is brought closer to the crankshaft by the movement direction changing member. At this time,
The spring presses the first clamp claw in the forward direction via the pressing member and the engagement arm. Then, when the first clamp claw advances to a predetermined position, the pressing member contacts the crankshaft, and the crankshaft is sandwiched between the locking member and the pressing member, and the phase is fixed.

When the first clamp claw further advances from this state, the pressing member comes into contact with the crankshaft and stops, so the engagement arm also stops, and therefore only the first clamp claw moves forward. The clamp claw and the engaging arm (pressing member) are mechanically cut off, and the biasing force of the spring does not act on the first clamp claw.

Then, the first clamp claw further advances together with the other clamp claws, and these come into contact with the crankshaft to chuck it. At this time, however, the pressing member and the first clamp claw are mechanically separated from each other. The reaction force applied to the pressing member from the crankshaft or the biasing force of the spring does not act on the first clamp claw. For this reason,
Since each clamp claw grips the crankshaft with the same gripping force, chuck misalignment does not occur. Therefore, the crankshaft can be rotated around the axis of the crankpin to be machined without causing rotational shake, and the machining accuracy of the crankpin can be improved.

When the clamp claws are retracted from the crankshaft to release the chucking of the crankshaft, when the first clamp claws retract from a predetermined position,
The clamp claw displaces the pressing member via the engaging arm in the direction opposite to the direction in which the spring biasing force acts, and thus the pressing member is displaced by the movement direction changing member in the direction away from the crankshaft, and King is released.

Further, the movement direction conversion member may have a simple structure such as an inclined plate that slidably contacts the pressing member at an appropriate angle with respect to the biasing direction of the spring. Therefore, the phase fixing means can have a simple structure in which a small engaging arm is provided between the first clamp claw and the pressing member, and a spring and an inclined plate are provided around the holding member. The holding device for machining the crankshaft can be made compact by, for example, grouping the phase fixing means in the floating chuck unit.

[Examples] Examples of the present invention will be specifically described below.

As shown in FIG. 1 and FIG. 2, the crankshaft machining holding device HS has a tapered tip portion inside a center hole 2 axially bored in the longitudinal end face of the crankshaft 1. By inserting the formed center support member 3 shallowly, the crankshaft 1 is supported rotatably around the axis of the journal portion 4, and the crank arm 7 is sandwiched between the locking member 5 and the pressing member 6 to fix the crankshaft 1 in a predetermined position. After fixing the phase (determining the phase), hydraulic pressure is applied to the floating chuck unit F, the journal portion 4 is gripped by the first to third clamp claws 8, 9 and 10 to chuck the crankshaft 1, and further the rotating means. Crankshaft 1 by 11
Is rotated around the axis of the crank pin 12 to be processed, and the crank pin 12 is subjected to predetermined processing such as cutting and polishing.

A cylindrical pilot bushing 16 integral with the chuck body 15 of the floating chuck unit F is provided at the center of the chuck body 15, and a center support member 3 is provided in a cylindrical space defined in the pilot bushing 16. The center support member 3 is slidably in contact with the inner peripheral surface of the pilot bushing 16 and can reciprocate in the axial direction thereof. The center support member 3
Is a cover member 26 that closes the end of the cylindrical space inside the pilot bushing 16 on the side opposite to the direction in which the crankshaft 1 is arranged (hereinafter, this direction is referred to as the side opposite to the crankshaft). The fixed compression spring 27 is constantly biased toward the crankshaft side, whereby the center support member 3 is engaged with the center hole 2 of the crankshaft 1 with an appropriate pressing force.

A substantially cylindrical draw sleeve 17 is fitted on the outer peripheral surface of the pilot bushing 16, and the draw sleeve 17 is slidably in contact with the outer peripheral surface of the pilot bushing 16 and can reciprocate in the axial direction thereof. The floating cam 19 is attached to the outer periphery of the draw sleeve 17.
Is attached using a sleeve nut 18 so that it can be slightly loosened in the radial direction of the draw sleeve 17. An inclined surface 19a is formed in a portion of the floating cam 19 corresponding to the first to third clamp claws 8 to 10 such that the radial thickness increases toward the crankshaft side.

A crank lever 22 rotatably supported around the fulcrum pin 21 is provided, and the first convex portion 22a of the crank lever 22 has a floating cam 19a.
The slidable surface 19a is slidably contacted. Further, the second convex portion 22b of the crank lever 22 has a corresponding clamp claw 8
The master jaw 23 attached to (9, 10) is engaged with the journal portion 4 in the radial direction.

Further, in the space 24 defined by the inner peripheral surface of the draw sleeve 17 and the lid member 26, hydraulic pressure is introduced or released via a draw screw 25 by hydraulic means (not shown). It is like this.

Here, when hydraulic pressure is introduced into the space 24, the draw sleeve 17 moves to the side opposite to the crankshaft along with the floating cam 19, and the floating cam 19
The crank lever 22 is rotated in the direction of the arrow A by the inclined surface 19a of the above, and the second convex portion 22b moves the master jaw 23 and the first to third clamp pawls 8, 9 and 10 together with the axial center of the journal portion 4 along with this. The crankshaft 1 is chucked by displacing in the direction and gripping the journal portion 4.

On the other hand, when the hydraulic pressure in the space 24 is released, the draw sleeve 17 (floating cam 19) is in a free state in which it can freely move in the axial direction, but the spring members (not shown) cause the first to third clamps to move. Since the claws 8, 9, 10 are returned to their original positions and the chucking of the crankshaft 1 is released, the master jaw 23 moves the crank lever 22 in the direction opposite to the arrow A with this. It is rotated so that the first convex portion 22a presses the inclined surface 19a toward the crankshaft side, and the floating cam 19 (draw sleeve 17) is returned to the position on the crankshaft side. Therefore, the first convex portion 22a and the inclined surface 19a
And are always in sliding contact.

When the crankshaft 1 is chucked, the first to third clamp pawls 8 to 10 approach the journal portion 4, respectively, but the clamp pawl 8 that first abuts the journal portion 4
(9, 10) receives a reaction force from the journal portion 4, and this reaction force is transmitted to the floating cam 19 via the crank lever 22. However, as described above, since the floating cam 19 can slightly move in the radial direction of the draw sleeve 17, the floating cam 19 moves away from the position corresponding to the clamp claw 8 (9, 10) that first contacts the journal portion 4. That is, since it is displaced so as to approach the positions corresponding to the other clamp claws 9 and 10, the gripping force applied from each clamp claw 8 to 10 to the journal portion 4 is equalized. This prevents the occurrence of chuck misalignment.

Hereinafter, the phase fixing means K for fixing the crankshaft 1 to a predetermined phase prior to the chucking of the crankshaft 1 will be described.

In the phase fixing means K, a pressing member 6 is arranged below the first clamp claw 8 in the vicinity thereof, and a locking member 5 is arranged in a position to sandwich the crank arm 7 in the horizontal direction. There is.

The pressing member 6 has an abutting portion 6b having a vertically extending surface facing the crankshaft 1, an engaging end 6a formed at the upper end of the corresponding abutting portion 6b, and a lower end of the abutting portion 6b. A connecting portion 6c to be formed and an inclined portion 6e extending upward from an end portion of the connecting portion 6c on the outer side in the radial direction of the journal portion 4 (hereinafter, simply referred to as an outer side) and having a slope 6d formed on the outer side are provided. There is.

A fixing pin 32 is provided just outside the contact portion 6b and above the connecting portion 6c. Then, in the space portion 31 formed between the contact portion 6b and the inclined portion 6e, the compression spring 33 having one end fixed to the fixing pin 32 and the other end fixed to the connecting portion 6c. The pressing member 6 is provided and is constantly urged downward by the compression spring 33.

Also, an engagement arm rotatably supported by the shaft portion 34.
35 is provided, and the engaging arm 35 has first and second engaging convex portions.
35a, 35b are formed, and the first engaging protrusion 35a abuts the lower surface of the engaging end 6a of the pressing member 6, while the second engaging protrusion 35b is the first
The claw-side engaging portion 8a formed on the lower surface of the clamp claw 8 comes into contact with the rear surface (the outer surface when viewed in the radial direction of the journal portion 4) (however, it does not make contact during chucking).

Further, on the outer side of the inclined portion 6e, an inclined member 36 having an inclined surface 36a in sliding contact with the inclined surface 6d is provided. And the slope
The pressing member 6 is slidably in contact with the inclined surface 36a of the inclined member 36.
Is displaced upward, the pressing member 6 is displaced in a direction away from the crank arm 7, and one pressing member 6 is moved.
When is displaced downward, the pressing member 6 is displaced in a direction approaching the crank arm 7.

The operation of the phase lock means K will be described below.

When the crankshaft 1 is not chucked, the first clamp claw 8 is at the most retracted position from the crankshaft 1. At this time, the claw-side engaging portion 8a of the first clamp claw 8 strongly urges the second engaging convex portion 35b of the engaging arm 35 in the backward direction P. On the other hand, the pressing member 6 urged downward by the compression spring 33 urges the first engaging convex portion 35a downward through the engaging end 6a, and the engaging arm 35
Try to rotate counterclockwise, but the second engaging projection 35
Since b is restricted from rotating counterclockwise by the claw side engaging portion 8a, it is stopped.

Here, in order to chuck the crankshaft 1, when the first clamp claw 8 moves in the forward direction Q toward the crankshaft 1 from this state, the second engaging protrusion 35b (engagement) is moved by the moved distance. Since the joint arm 35) can rotate counterclockwise, the pressing member 6 is displaced downward by the urging force of the compression spring 33 by the amount corresponding to this, and the pressing member 6 is inclined accordingly. It is displaced to the crank arm 7 side by 36. Then, when the first clamp claw 8 advances to a predetermined position, the pressing member 6 causes the contact portion 6b to move toward the crank arm 7.
The crank arm 7 is slightly clockwise rotated, and the crank arm 7 is sandwiched between the locking member 5 and the crank arm 7 and fixed. In this way, the crankshaft 1 is fixed in a proper phase.

When the first clamp claw 8 is further advanced in the Q direction from this state, the pressing member 6 is in contact with the crank arm 7 and cannot be displaced downward any further, so that the engaging arm 35 is further rotated counterclockwise. It will not be able to rotate. Therefore, although the claw side engaging portion 8a advances in the Q direction,
Since the second engaging portion 35b is stopped, the claw-side engaging portion 8a and the second engaging convex portion 35b are separated from each other, and the first clamp claw 8 and the pressing member 6 are mechanically disconnected.

After that, the first clamp claw 8 further advances in the Q direction and comes into contact with the journal part 4 of the crankshaft 1, and at the same time, the second and third clamp claws 9 and 10 also come into contact with the journal part 4, The crankshaft 1 is chucked by gripping the journal portion 4 with the first to third clamp claws 8 to 10. At this time, since the pressing member 6 and the first clamp claw 8 are mechanically disconnected, the reaction force acting on the pressing member 6 from the crank arm 7 or the biasing force of the compression spring 33 acts on the first clamp claw 8. do not do. Therefore, the floating chuck unit F works effectively, and
Since the third clamp claws 8 to 10 grip the crankshaft 1 with the same gripping force, chuck misalignment does not occur.
Therefore, the crankshaft 1 can be rotated around the axis of the crank pin 12 to be processed without causing rotational shake, and the machining accuracy of the crank pin 12 can be improved.

When the first clamp claw 8 retracts in the P direction in order to release the chucking of the crankshaft 1, the claw side engaging portion 8a of the first clamp claw 8 moves the second engaging convex portion 35b to the P direction.
Direction, the engaging arm 35 is rotated in the clockwise direction, and the pressing member 6 is displaced upwards accordingly, so that the pressing member 6 is displaced by the tilting member 36 in the direction away from the crank arm 7. Then, the chucking of the crankshaft 1 is released.

[Brief description of drawings]

FIG. 1 is a front elevational view of a crankshaft machining holding device showing an embodiment of the present invention as seen in the axial direction of the crankshaft. FIG. 2 is a side cross-sectional explanatory view of the crankshaft processing holding device shown in FIG. FIG. 3 is a front elevational view of a conventional crankshaft machining holding device as viewed in the axial direction of the crankshaft. HS: Holding device for crankshaft processing, F: Floating chuck unit, K: Phase fixing means, 1 ...
… Crankshaft, 2 …… Center hole, 3 …… Center support member, 4 …… Journal part, 5 …… Locking member, 6
...... Pressing member, 7 ...... Crank arm, 8 to 10 ...... First to third clamp claws, 11 ...... Rotating means, 12 ...... Crank pin, 19 ...... Floating cam, 33 ...... Compression spring, 35 ... ... Engaging arm, 36 ... Tilt member.

Claims (1)

[Scope of utility model registration request] 1. A center support member that engages with a center hole formed in an end portion of a crankshaft to rotatably support the crankshaft around an axis of a journal portion thereof, and a crank supported by the center support member. A phase fixing means for fixing the shaft to a predetermined phase by sandwiching the shaft with a locking member and a pressing member; and a floating chuck unit for chucking the crankshaft whose phase is fixed by the phase fixing means with a plurality of clamp claws, A crankshaft machining holding device provided with rotating means for rotating a chucked crankshaft about an axis of a crankpin to be machined, a spring for urging a pressing member in a predetermined direction, and a predetermined one. When the two clamp claws retract from the crankshaft While the clamp claw and the pressing member are engaged so as to displace the pressing member in the direction opposite to the biasing direction of the spring against the biasing force of the spring, while the clamp claw advances toward the crankshaft. An engaging arm that releases the engagement between the clamp claw and the pressing member when the clamp claw approaches the crankshaft, and a pressing member approaches the crankshaft when the pressing member is displaced in the urging direction by the spring. Direction to lock the phase of the crankshaft, while the pressing member is displaced in the direction opposite to the spring biasing direction, the pressing member is displaced in the direction away from the crankshaft to lock the phase of the crankshaft. And a moving direction changing member for releasing the clutch. Kushafuto processing for the holding device.