JPH0340493Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial field of application] The present invention is useful for turning a workpiece such as a crankshaft in which the gripped part and the workpiece part are eccentric. It relates to a chuck for rotating and fixedly supporting the lathe so that it coincides with the main axis of the lathe.

[Conventional technology]

Conventionally, when machining a workpiece on a lathe, the workpiece is chucked so that it is aligned with the main axis of the lathe, the workpiece is rotated by the main axis in this state, and the cutting feed is applied to the cutting tool for turning. There is.

By the way, when machining a crank pin hole in the crank arm of a crankshaft, for example, the crankshaft part which is the part to be gripped and the crank pin hole which is the part to be machined are eccentric, and the crankshaft having such an eccentric machined part is For workpieces, so-called phasing is required, in which the crank arm is rotated and fixed at a predetermined angle position around the crankshaft so that the crank pin hole coincides with the main shaft when chucked.

Therefore, as a chuck capable of performing the above-mentioned phasing, conventionally, two phasing arms, a left and a right phasing arm, are attached to the chuck body for free rotation to clamp the processed part of the workpiece from the left and right sides at the main shaft position of the lathe. There was also a device that was further provided with a phasing drive source for rotationally driving the phasing arm.

[Problem that the invention attempts to solve]

In the conventional chuck mentioned above, the left and right phasing arms press the workpiece against each other from the left and right directions, so if the pressing forces of the left and right arms are perfectly matched, the workpiece can be moved to the spindle position. can be positioned. However, in general, it is difficult to perfectly match the pressing forces on the left and right sides, and the pressing force on either side becomes large and tends to deviate to either side, resulting in the problem of low phasing accuracy in the conventional chuck. It was hot.

In addition, the conventional chuck described above requires a phasing drive source in addition to the chucking drive source.
The problem was that the structure was complicated and the cost was high.

[Means for solving problems]

The present invention is a chuck for supporting a workpiece in which the gripped part and the machined part are eccentric, and includes a chuck body that grips the gripped part of the workpiece by a driving force in the main axis direction from a chuck drive source of a lathe, and a chuck that supports the workpiece in an eccentric manner. A phasing seat and a phasing arm for rotating and fixing the machining part to the main shaft position, and a rotating drive for the phasing arm by converting the driving force in the main shaft direction from the chuck drive source into rotational driving force. A phase determining drive unit is provided.

[Effect]

In the chuck according to the present invention, the chuck main body grips the gripped part of the workpiece by the driving force from the chuck driving source of the lathe, and the phasing drive unit rotationally drives the phasing arm by the same driving force. As a result, the workpiece is rotated so that the part to be processed is located at the main axis position, and is fixed in this state.

〔Example〕

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

1 to 4 show a chuck according to an embodiment of the present invention attached to the main shaft of a lathe,
In the figure, 1 is a main shaft, a drive motor (not shown) is connected to the base end of the main shaft 1, and a main shaft flange 2 is disposed at the tip.
The main shaft flange 2 is a disc-shaped member having a rectangular through hole 2c at its axis, and its fitting recess 2a is fitted into the fitting protrusion 1a of the main shaft 1, and the mounting bolt 3
It is bolted and fixed to the main shaft 1.

A draw bar 4 is inserted into a draw hole 1b formed through the axis of the main shaft 1 so as to be movable in the left-right direction in FIG. The drawbar 4 is a rod-shaped member having an air passage 4a at its axis, and a driving cylinder (not shown) serving as a chucking drive source is connected to its base end, and a draw joint 5 is connected to the air passageway at its tip. It is fixed by a connecting bolt 6 having a diameter 6a. A substantially rectangular joint portion 5a is integrally formed at the front portion of the draw joint 5, and is located within the through hole 2c. A locking recess 5b is provided in the joint portion 5a, and a sliding hole 5c is formed in the front wall constituting the locking recess 5b. Note that 7 is a stopper member that comes into contact with the joint portion 5a.

A chuck sliding surface 2b is recessed in the front end face of the main shaft flange 2 so as to be orthogonal to the main shaft 1, and an arcuate guide plate 8 is bolted to the left and right edges of the front end face in FIG. A chuck guide groove 9 extending perpendicularly to the main shaft 1 is formed by the left and right guide plates 8 and the chuck sliding surface 2b.

And the chuck sliding surface 2 of the main shaft flange 2
A chuck 10 is disposed on b so as to be slidable in a direction perpendicular to the main shaft 1. The chuck 10 mainly includes a chuck body 12, a chuck portion 42, and a phase determining portion 40. The chuck main body 12 includes a rectangular columnar body 11 and a chuck flange 12 fixed to the rear end surface thereof with bolts.
The left and right edges of this chuck flange 12a are slidably fitted into the guide groove 9. The body 11 also has a chuck hole 11a and a phase determining hole 11b extending parallel to the main shaft 1.
is formed.

The cylindrical sleeve 13 of the chuck portion 42 is inserted into the chuck hole 11a, and the rear end of the sleeve 13 is bolted and fixed to the chuck flange 12a. A large diameter tapered pressing portion 13a is formed. A cylindrical collet 14 is inserted into the sleeve 13 so as to be movable in the direction of the main shaft 1, and a slit 14 is formed at the tip of the collet 14.
a and the tapered portion 14 that fits into the pressing portion 13a.
A gripping portion 14c having a shape b is formed. Note that 14d and 12b are air holes for air blowing.

A joint rod 15 is bolted and fixed to the rear end of the collet 14, and a locking flange 15a integrally formed at the rear end of the joint rod 15 is located within the locking recess 5b of the joint portion 5a. ing. Furthermore, an annular reference plate 16 is fixed to the front end surface of the body 11 with bolts.
The rear surface of the sleeve 6 serves as a stopper surface that comes into contact with the front end surface of the sleeve 13, and the front surface serves as a reference surface in the axial direction of the workpiece. Note that 16a is an escape groove for preventing the cutting tool from interfering with the cutting tool.

The phase determining section 40 is connected to the chuck section 4.
2 in the upper part of Figure 1. This phasing section 40 is composed of a phasing member 41 for rotationally fixing the part to be processed on the workpiece, and a phasing drive section 17 for rotationally driving the phasing member 41. It is disposed within the phase determining hole 11b. A cylindrical drive member 18 of this phase determining drive section 17 is slidably inserted into the phase determining hole 11b, and a push pin portion 18a integrally formed at the rear end thereof passes through the chuck flange 12a. and faces the joint portion 5a. Further, a drive screw 19, which is a female screw, is attached to the front end of the drive member 18. A guide ring 22 is disposed on the bottom of the phase determining hole 11b, and a guide ring 22 is disposed between the bottom and the drive screw 1.
A plurality of biasing springs 23 are disposed between the springs 9 and 9. Note that 20 is a guide pin that prevents rotation of the drive member 18 and guides it in the axial direction.

Further, a male driven screw 21 is screwed into the drive screw 19, and a support member 24 is screwed onto the front end of the driven screw 21.
is rotatably supported by the body 11 by a bearing 25. Note that 27 is a bearing holding plate.

The phasing member 41 is composed of a phasing arm 26 that presses and rotates the workpiece, and a phasing seat 28 that receives the workpiece.
6 is attached to the support member 24. The phasing arm 26 has a substantially triangular flat plate shape and has a convex portion 26a for engaging with the support member 24 and a workpiece pressing portion 26b. The phasing seat 28 is a flat plate, and is bolted and fixed to a position adjacent to the phasing arm 26 of the body 11. This serves as a receiving portion 28a.

A positioning portion 29 for fixing the chuck 10 at a predetermined position is formed at the upper portion of the main shaft flange 2 in FIG. This positioning part 2
9 mainly consists of a support plate 30, a moving bolt 31, and a liner plate 33. The support plate 30 is a rectangular flat plate, and is fixed to the main shaft flange 2 with bolts, and the movable bolt 31 is inserted into a bolt insertion hole 30a formed through approximately the center of the support plate 30. There is. This moving bolt 3
A cylindrical guide member 32 is fixed to the chuck flange 1, and the lower end of the bolt 31 is connected to the chuck flange 1.
It is screwed onto the upper end of 2a. A liner plate 33 is inserted between this support plate 30 and the chuck 10.
A variety of thicknesses are available in accordance with the amount of eccentricity of the workpiece to be machined, and the larger the amount of eccentricity, the thicker one is selected.

Next, the effects of this embodiment will be explained.

The chuck 10 of this embodiment is a crank arm portion W3 of a crankshaft W for a two-wheeled vehicle, which is a workpiece.
This is for machining a crank pin hole W2 at a position offset by L from the crank main shaft portion W1.

To chuck with a crankshaft W having an eccentricity L, first position and fix the chuck 10 at a position corresponding to the eccentricity L, and then rotate the crankshaft W so that its crank pin hole W2 is at the main shaft position. and then chuck in this state.

To do this, first, the drive cylinder for the drawbar 4 is extended. Then, the drawbar 4 moves forward, and the rear wall of the locking recess 5b pushes the joint rod 15 forward, causing the collet 14 to move forward and the gripping part 14c to have a size in which the crank main shaft part W1 can be inserted.

At this time, the joint portion 5a also presses the push pin portion 18a of the phase determining portion 40 to advance the drive member 18, thereby causing the driven screw 21 screwed with the drive screw 19 to rotate clockwise in FIG. As the phasing arm 26 rotates, the distance between the workpiece pressing portion 26b of the phasing arm 26 and the workpiece receiving portion 28a of the phasing seat 28 becomes wider.

Also, as the collector 14 moves forward, the chuck 10
The pressing force on the main shaft flange 2 is reduced, so that the chuck can slide on the chuck sliding surface 2b. Therefore, the chuck 10 is the movable bolt 3
If you loosen 1, it will move in a direction perpendicular to the main shaft 1. In this state, the liner plate 33 is replaced with one corresponding to the eccentricity L, and the moving bolt 31 is tightened again. Then, the chuck 10 is positioned at a position corresponding to the crankshaft W having the above eccentricity L.

Next, the crank main shaft portion W1 of the crankshaft W
is inserted into the collect 14 so that the crank arm part W3 is located between the workpiece pressing part 26b and the workpiece receiving part 28a, and its rear surface is in contact with the reference plate 16, and in this state, the drawbar 4 is
deflate the drive cylinder. Then, the collet 14 is pulled rearward by the draw joint 5, and the grip part 14c of the collet 14 pulls the crank main shaft part W.
1 is grasped. At this time, the driving screw 19 of the phase determining portion 40 is urged by the biasing spring 23 and moves backward, so that the driven screw 21 rotates the phase determining arm 26 counterclockwise in FIG. 3. Then, the workpiece pressing portion 26b of the arm 26 presses the crank arm portion W3 of the crankshaft W against the workpiece receiving portion 28a of the phasing seat 28. As a result, the crankshaft W is chucked with its crank pin hole W2 aligned with the axis of the main shaft 1, and the hole is machined in this state.

Note that when chucking a crankshaft having eccentricities L1 and L2 different from those described above, the liner plate 33 can be replaced with one having a thickness corresponding to the eccentricities L1 and L2. 10 is positioned at a position corresponding to the crankshaft of each eccentricity L1, L2,
Also, at this time, the crankshaft is connected to the phase determining section 40.
As a result, the crank pin W2 is rotated so as to be aligned with the main shaft, and is fixed in that state.

In this way, in this embodiment, the phase determining arm 26 of the phase determining section 40 can be rotated by the driving force in the main axis direction from the chuck drive source, so that the phase determining arm 26 of the phase determining section 40 can be rotated using only the chuck drive source without the need for a phase determining drive source. The phase of the workpiece can be determined by using the 3-axis method, which simplifies the structure and reduces costs. In this case, since the crank arm part W3 is pressed against the fixed phasing seat 28 with the phasing arm 26, the phasing can be determined in the same way as in the conventional case where it is held between two movable arms. The problem of low accuracy can also be solved.

In addition, in this embodiment, the chuck 10 can be positioned at a position corresponding to the eccentricity of the work simply by replacing the liner plate 33, and setup work can be performed very quickly and easily, resulting in improved machining efficiency. can be improved.

In the above embodiment, the chuck 10 is configured to be movable in a direction perpendicular to the main shaft 1 so as to be able to support workpieces having different eccentricities, but in the present invention, the chuck does not necessarily have to be movable.

Further, in the above embodiment, a case has been described in which the phasing drive section 17 is composed of a combination of the drive screw 19 and the driven screw 21, but the phasing drive section of the present invention is not limited to such a mechanism. For example, a rack and pinion mechanism, a crank mechanism, a link mechanism, etc. can be employed, and the structure may be such that the workpiece to be processed is rotated to the main axis position using the driving force of the chuck drive source and fixed in this state.

[Effect of idea]

As mentioned above, according to the chuck of the present invention,
A phasing seat and a phasing arm that rotate and fix the workpiece so that the workpiece is at the main axis position, and a phasing drive unit that rotationally drives the phasing arm by a driving force from a chuck drive source. As a result, the phase of the workpiece can be determined with a simple structure without requiring a drive source for phasing, and the phasing accuracy can be improved.

[Brief explanation of drawings]

1 to 4 show a chuck according to an embodiment of the present invention attached to the main shaft of a lathe,
1 is a sectional side view thereof, FIG. 2 is a partially sectional plan view thereof, FIG. 3 is a front view thereof, and FIG. 4 is a sectional front view thereof. In the figure, 1 is the main shaft, 10 is the chuck, and 12
is the chuck body, 17 is the phasing drive part, 26 is the phasing arm, 28 is the phasing seat, W is the crankshaft (workpiece), W1 is the crank main shaft part (grasped part), W2 is the crank pin hole (workpiece part) Department)
It is.

Claims (1)

[Scope of utility model registration request] A chuck for supporting a workpiece in which a gripped part and a to-be-processed part are eccentric so that the to-be-processed part is aligned with the main axis of a lathe, and is driven by a driving force in the main axis direction from a chuck drive source of the lathe. A chuck body that grips a gripped portion of a workpiece; a phasing seat that is fixed to the chuck body and comes into contact with the workpiece portion of the workpiece at a spindle position; a phasing arm that rotates the workpiece toward the phasing seat; and a phasing drive that converts the driving force in the main axis direction from the chuck drive source into rotational driving force to rotationally drive the phasing arm. A chuck characterized by having a section.