JPH03121762A - Chuck device and work holding method - Google Patents

Abstract

PURPOSE:To hold a work in a correct posture at all times and to perform the work after its holding with high accuracy, by providing a positioning member exerting a centripedal action. CONSTITUTION:A holding mechanism equipped with freely closable holding jaws 18 to hold the outer periphery of a work (lens raw material) 17 and an adsorptive cylinder 22 located coaxially with the center of this holding mechanism and freely adsorptive of the work with its tip are provided. Moreover, a positioning member 20 located coaxially with this adsorptive cylinder 22 and performing the centripedalism of the work 17 by engaging with the engaging part 17b provided on the work 17 is provided, the work 17 is made centripedal by this positioning member 20, even in case of the inclination being caused at the time when the work 17 is adsorbed by the adsorptive cylinder 22 and the posture is corrected.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a chuck device that grips the outer periphery of a workpiece when machining the end face, outer peripheral surface, etc. of the workpiece.

[Prior Art] Conventionally, as a chuck device, for example,
One disclosed in Japanese Patent No. 3546 is known. This chuck device is as shown in FIGS. 3(a) and 3(b), in which a collet chuck 2 and a tightening ring 3 are provided at the tip of a lens holding shaft 1. Inside the collet chuck 2, a suction cup mounting shaft 5 with an air hole 4 bored in the shaft center is provided so as to be slidable in the axial direction, and on the tip side of the collet chuck 2, a suction cup rubber 6
is fixed, and an air suction tube 7 is attached to the opposite end. To attach the suction cup, an air valve 8 is screwed onto the shaft 5 in a direction perpendicular to the axis. A compression spring 9 is inserted between the end surface of the suction cup mounting shaft 5 on the side where the air suction tube 7 is mounted and the opposing surface of the inner space of the collet chuck 2.

The air valve 8 passes through an axially long notch 1o provided in the side wall of the collet chuck 2, and the suction cup can be attached to the shaft 5 by holding its head and sliding it inside the notch 10. It can be pulled in against the spring 9. The suction cup attachment can hold the shaft 5 at a position where the lens surface of the lens 11 adsorbed by the suction cup rubber 6 fully contacts the lens holding reference surface 12 provided at a position slightly beyond the tip of the collet chuck 2. A retaining pawl 13 for retaining the air valve 8 is pivotally supported by a pin 14 implanted in the side surface of the collet chuck 2.

In the chuck device having such a configuration, first, the polished surface of the lens 11 is pressed against the sucker rubber 6, and the suction is sucked from the air suction tube 7 by a vacuum pump (not shown).
is held by the sucker rubber 6. Next, hold the air valve 8 and pull in the suction cup mounting shaft 5 against the force of the spring 9.
At the position where the peripheral part of the lens surface adsorbed by the suction cup rubber 6 of 1 is in close contact with the lens holding reference surface 12, insert the stopper claw 13 into the air valve 8.
to hold the lens in place.

Thereafter, the collet chuck 2 is tightened by tightening the ring 3. In this case, it is sufficient to simply retract the chuck 2 until the inner surface of the tip of the collet chuck 2 comes into contact with the outer peripheral surface of the lens 11 held by the suction cup rubber 6, and there is no need to tighten it with a tightening force.

As a result of the above, the lens 11 is held at a predetermined lens holding reference position of the chuck with the entire circumference in close contact with the lens 11, and displacement in the radial direction is prevented by the collet chuck 2. Then, processing is performed in this state.

Next, remove the lens 11 using the following procedure.

First, loosen ring 3 for tightening. This opens the chuck 2. When the pneumatic valve 8 and the stopper claw 13 are unlatched, the suction cup mounting shaft 5 moves forward by the force of the spring 9, and the lens 11 comes to a position protruding from the tip of the collet chuck 2. Thereafter, when the air valve 8 is opened and atmospheric pressure is introduced into the air hole 4 in the shaft 5 to attach the suction cup, the lens 11 is removed from the suction cup rubber 6.

[Problems to be Solved by the Invention] However, in the conventional chuck device, the suction cup rubber 6 and the lens 11 are not provided with a structure in which they act centripetally to each other, and the lens 11 is attracted while being tilted. When the lens 11 was held, the posture of the lens 11 could not be corrected. Therefore, it was difficult to perform high-precision machining after holding.

The present invention has been made in view of such conventional problems, and provides a chuck device and a workpiece holding method that can always hold a workpiece in the correct posture by providing a positioning member that acts centripetally. The purpose is to

[Means to solve the problem]

In order to achieve the above object, the present invention provides a chuck device for gripping the outer periphery of a workpiece. It is equipped with a suction tube that is located at the center of the workpiece and can freely suck the workpiece at its tip, and a positioning member that is located coaxially with the suction tube and engages with a retaining part provided on the workpiece to centripetalize the workpiece. It is something that

Moreover, the present invention holds a workpiece using a chuck device having such a configuration.

[Effect]

According to the chucking device and workpiece holding method configured as described above, when the workpiece is suctioned by the suction tube, even if the workpiece is tilted, the positioning member centripetally corrects the posture of the workpiece.

〔Example〕

(First Embodiment) FIG. 1 shows the chunking device of this embodiment, in which an actuator 16 is attached to the support member 15 as a gripping mechanism, and the tip of the actuator 16 is attached to a workpiece. A gripping claw 18 that can be opened and closed is provided to grip the outer periphery of a certain lens material 17. In addition, the support member 15
A substantially cylindrical positioning member 19 is attached to the center of the actuator 16 coaxially with the actuator 16 . A cylindrical positioning rod 20 is provided at the center of the positioning member 19. The lower end of the positioning rod 20 is located near the tip of the gripping claw 18, and four conical parts 20a are formed at the center of the lower end surface.

Further, inside the positioning member 19, a cylindrical suction cylinder 22 is provided coaxially therewith so as to be slidable in an airtight manner relative to the positioning member 19. An outer flange 22a is formed on the upper edge of the suction tube 22, and is engaged with an inner flange 19a provided on the lower edge of the positioning member 19 to prevent the suction tube 22 from falling. The suction tube 22 can adsorb the lens material 17 by bringing its tip into contact with the lens surface 17a of the lens material 17.

Further, the support member I5 is provided with an air suction passage 23, and this air suction passage 23 communicates with the positioning member 19 and the interior of the suction tube 22. The air suction passage 23 is connected to a vacuum pump (not shown).

On the other hand, the lens surface 17a on the suction side of the lens material 17
, a recess 20a provided on the lower end surface of the positioning rod 20.
An engaging portion 17b consisting of a conical projection is formed correspondingly.

In the chunk device having such a configuration, for example, the suction cylinder 2 is lowered by its own weight with respect to one lens surface 17a of the lens material 17 transported by a transport device (not shown).
Touch the tips of 2. Then, the lens material 17 is suctioned by a vacuum pump through the air suction passage 23 and the like, and the lens material 17 is suctioned at the tip of the suction tube 22 . after that,
Further suction is continued to raise the suction cylinder 22, and the retaining part 17b provided on one lens surface 17a is attached to the positioning rod 20.
The suction tube 22 until it fits into the recess 20a provided on the lower end surface of the
to rise.

At this time, the lens material 17 is positioned in its thickness direction, and at the same time, a centripetal action is performed and the lens material 17 is attracted in a correct posture.

Next, the actuator 16 is moved to close the gripping claws 18 to grip the outer periphery of the lens material 17. Thereafter, the suction is stopped, and while the lens material 17 is being held by the gripping claws 18, a predetermined processing is performed on the lens material 17.

After processing, suction is performed again using the vacuum pump, and the suction cylinder 2
After the lens material 17 is suctioned at the tip of the actuator 16, the gripping claw 18 of the actuator 16 is closed to release the grip, and the lens material 17 is held only by the suction tube 22. Then, after the suction force is slightly weakened and the suction cylinder 22 is lowered, suction is stopped and the lens material 17 is returned to the conveyance device.

In this way, according to this embodiment, after the lens material 17 is attracted, the recess 20a of the positioning rod 20 and the engaging portion 17b of the lens material 17 perform positioning in the thickness direction and centripetal action. Even if the lens material 17 is in its original position and is attracted, it is corrected to the correct posture by the positioning rod 20, and subsequent processing can be performed with high precision.

(Second Embodiment) FIG. 2 shows the chunk device of this embodiment.
Similarly to the embodiment, an actuator I6 for opening and closing the gripping claw I8 is attached to the support member 15. Further, a substantially cylindrical rod support member 24 is attached to the support member 15 at the center of the actuator 16 and coaxially with the actuator 16 . This rod holder is member 2
4, a positioning rod 25 is inserted and screwed together, and the positioning rod 25 is provided so as to be fixable at an arbitrary position with a screw 26. And the positioning rod 25
The tip is located near the tip of the gripping claw 18, and a conical recess 25a is formed at the center of the tip surface. Further, the peripheral edge of the tip end of the positioning rod 25 is chamfered.

A substantially cylindrical locking ring 27 is screwed onto the outer periphery of the rod receiver member 24 . The inner flange 27a provided at the tip of the locking ring 27 locks the flange 22a of the suction tube 22, which is always urged in the forward direction (rightward in FIG. 2) by the compression spring 28. There is. The tip of the suction tube 22 (the tip that comes into contact with the lens material 17) is formed into a spherical shape.

Further, the support member 15 is provided with an air suction passage 23 in the same manner as in the first embodiment. Furthermore, lens material 1
On the suction side lens surface 17a in 7, a retaining portion 17b consisting of a conical protrusion formed during molding of the lens material 17 is formed in correspondence with the recess 25a provided on the tip end surface of the positioning rod 25. .

In a chuck device having such a configuration, for example, the tip of the suction tube 22, which is moved forward by the force of the compression spring 28 and squeezes, is brought into contact with one lens surface 17a of the lens material 17 conveyed by a conveyance device (not shown). let Then, the lens material 17 is suctioned by a vacuum pump through the air suction passage 23 and the like, and the lens material 17 is suctioned at the tip of the suction tube 22 . Furthermore, strong suction is performed by the vacuum pump, and the suction cylinder 22 is moved backward against the force of the compression spring 28, until the suction cylinder 22 move. At this time, the lens material 17 is positioned in its thickness direction, and at the same time, a centripetal action is performed and the lens material 17 is attracted in a correct posture.

Next, the actuator 16 is driven to close the gripper 8 to grip the outer periphery of the lens material 17. Thereafter, the suction is stopped, and while the lens material 17 is being held by the gripping claws 18, a predetermined processing is performed on the lens material 17.

After processing, suction is performed again using the vacuum pump, and the suction cylinder 2
After the lens material 17 is suctioned at the tip of the lens material 2, the gripping claw 18 of the actuator 16 is opened to release the grip, and the lens material 17 is held only by the suction cylinder 22. Then, the suction force is slightly weakened, and the suction tube 22 is moved by the force of the compression spring 28.
After moving forward, suction is stopped and the lens material 17 is returned to the conveying device.

As described above, according to the present embodiment, the same effects as in the first embodiment can be obtained, and since the tip of the suction tube 22 is spherical, the lens material 17 can be positioned. When the lens material 17 is clamped by the gripping claws 18 of the actuator 16, the lens material 17 becomes easier to move. In addition, the lens surface 1 of the lens material 17
It has the effect of being easy to attract regardless of the size of the curvature of 7a.

Furthermore, since the positioning rod 25 can be adjusted in accordance with the thickness of the lens material 17, the chuck device can be provided with versatility.

〔Effect of the invention〕

As described above, according to the chuck device and workpiece holding method of the present invention, since the positioning member that performs centripetal action is provided, the workpiece can always be held in the correct posture, and machining after holding can be performed. This can be done with high precision.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway side view showing a first embodiment of a chuck device of the present invention, FIG. 2 is a partially cutaway side view showing a second embodiment of the present invention, and FIG. 3(a) is a conventional chuck device. FIG. 3(b) is a longitudinal cross-sectional view showing the chuck device, and FIG. 3(b) is a plan view showing a main part of the chuck device shown in FIG. 3(a). Fig. 1 16... Actuator 17... Lens material 17b... Holding part 18... Gripping claw 19... Positioning member 20, 25... Positioning rod 20a, 25a... Recessed part

Claims (2)

[Claims] (1) In a chuck device that grips the outer circumference of a workpiece,
A gripping mechanism equipped with gripping claws that can be opened and closed to grip the outer periphery of a workpiece, a suction tube located coaxially at the center of this gripping mechanism and capable of sucking the workpiece at its tip, and a suction cylinder coaxially located with the suction tube. A chuck device comprising: a positioning member that engages with an engaging portion provided on a workpiece to centripetally center the workpiece. (2) A method for holding a workpiece, comprising holding the workpiece by the chuck device according to claim 1.