JPH03117547A - Chuck device - Google Patents

Abstract

PURPOSE:To avoid distortion and uneven thickness of workpiece so as to enable high accuracy machining by mounting a movable means in axial direction of an actuator so that a workpiece adsorbed on an adsorptive cylinder makes contact with a positioning ring. CONSTITUTION:An adsorptive cylinder 3 which holds a workpiece 4 is pulled in along the axial line of an actuator 1 and the workpiece 4 is moved until it makes contact with a positioning ring 5. At this time, whether the workpiece 4 makes accurate contact with the positioning ring 5 is judged by degree of vacuum pressure in an air suction passage 7. The holding claw 2 of the actuator 1 is closed to hold the workpiece 4 so as to perform machining only when the workpiece 4 makes accurate contact with the positioning ring 5. Thus, it is possible to avoid distortion and uneven thickness of workpiece so as to perform high accuracy machining.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a chuck device for a processing machine that grips a workpiece and processes one end surface or outer peripheral surface of the workpiece.

[Conventional technology]

As an example of the prior art of this type of chuck device, a lens holding chuck disclosed in Japanese Utility Model Application Publication No. 59-173546 will be described below with reference to FIG.

First, a collet chuck 2 is attached to the tip of the lens holding shaft l.
A ring 3 is provided to tighten it. On the inside of the collet chuck 2, a suction cup with an air hole 4 drilled in the shaft center is provided with a shaft 5 slidable in the axial direction, and a suction cup rubber 6 is fixed to the tip side of the collet chuck 2. An air suction tube 7 is attached to the opposite end.

For mounting the suction cup, a pneumatic valve 8 is screwed onto the shaft 5 in a direction perpendicular to the axis. For mounting the suction cup, a compression spring 9 is inserted between the end surface of the 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 pneumatic valve 8 passes through an axially long notch lo provided on 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 lo. It can be pulled in against the spring 9. The suction cup attachment allows the shaft 5 to be held 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.

The operating procedure for holding the lens with this lens holding chuck is to press the polished surface of the lens 11 against the rubber suction cup 6, suck it from the air suction tube 7 with a vacuum pump (not shown), and hold the lens 11 on the rubber suction cup 6. Next, hold the air valve 8 and pull in the suction cup mounting shaft 5 against the force of the spring 9 until the peripheral part of the lens surface that is attracted to the suction cup rubber 6 of the lens 11 is in close contact with the lens holding reference surface 12. After the retaining claw 13 is engaged with the air valve 8 to hold the lens in that position, the collet chuck 2 is tightened by tightening the ring 3 to hold the lens at the reference lens holding position of the chuck 2. .

[Invention tries to solve! ! ! 11) However, in the lens holding chuck described in the above-mentioned Japanese Utility Model Publication No. 59-173546, the lens sucked by the suction rubber is brought into contact with the lens holding reference surface provided at a position slightly below the tip of the collet chuck. At the same time, the lens is held and processed by tightening the collet chuck to avoid lens distortion and variations in wall thickness.In this configuration, the lens holding reference surface (collet chuck side),
Alternatively, even if foreign matter is attached to the lens suction surface, the lens is simply brought into contact with the holding reference surface, chucked, and processed, resulting in high precision that avoids lens distortion and wall thickness variations. The problem is that it is difficult to process.

The present invention has been made in order to solve the problems in the prior art as described above, and allows the workpiece to be accurately positioned on the holding reference surface (without any foreign matter intervening between the workpiece and the holding reference surface). To provide a chuck device that avoids distortion of a workpiece and variations in wall thickness and enables high-precision machining by determining whether a workpiece is in contact and performing machining only when it is in accurate contact. The purpose is to

(Means and Effects for Solving the Problems) A conceptual diagram of the present invention is shown in FIG. 1 and will be described below.

The present invention is directed to an actuator 1 having a gripping claw 2 that can be opened and closed to grip a workpiece 4, and an actuator 1 that is provided coaxially inside the actuator 1, that attracts the workpiece 4, and that has a tip that is movable in the axial direction. A suction cylinder 3 having an elastic body 3a, and a flow path 6 (which is provided coaxially with the actuator 1 on the outside (or inside) of the suction cylinder 3, positioned in the thickness direction of the workpiece 4, and through which fluid flows). The ring 5 having an air suction passage 1) and the workpiece 4 adsorbed by the suction cylinder 3 are in contact with the positioning ring 5 when the actuator 1 is moved.
means movable on the axis of the

The suction tube 3 is initially located at a position protruding from the chuck device main body as shown in FIG. 1(C), and the workpiece 4 is
Vacuum adsorption. By further drawing a vacuum from this state, the suction tube 3 holding the workpiece 4 is drawn in along the axis of the actuator 1, and moves until the workpiece 4 comes into contact with the positioning ring 5, as shown in FIG. The situation will be like a). At this time, if something like a foreign object 8 is interposed between the reference surface of the positioning ring 5 (the surface that contacts the workpiece 4) and the workpiece 4, and the workpiece 4 is not in accurate contact with the suction cylinder 3. As shown in FIG. 1(a), a slight gap is created between the workpiece 4 and the reference surface of the positioning ring 5, and air suction passages I provided in the positioning ring 5 are drawn through the gap. By forming such a flow path for the air to flow into the air suction passage 7,
The vacuum pressure of the air flowing through the area will decrease. By comparing this decrease in vacuum pressure with the vacuum pressure during normal suction using a vacuum gauge (not shown), it is determined whether the workpiece 4 is in accurate contact with the positioning ring 5.

By using the above-mentioned means and only when the workpiece 4 and the positioning ring 5 are in accurate contact with each other, the gripping claw 2 of the actuator 1 is closed to hold the workpiece 4 and machining is performed. It is possible to perform high-precision machining that avoids variations.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

(First Embodiment) FIG. 2 is a sectional view showing a first embodiment of the chuck device of the present invention.

2 is a scroll chuck; 2 is a gripping claw attached to the scroll chuck 1; 3 is a suction cylinder having a rubber elastic body 3a at the tip for suctioning a workpiece and has a suction hole 3b; 4 is a workpiece. 5 is a positioning ring for positioning the workpiece 4 in the thickness direction, 6 is an air suction passage I provided in the positioning ring 5, and 7 is for drawing air into the suction tube 3 from a vacuum pump (not shown). air suction passage H18
9 is a foreign object, and 9 is a spring inserted in the positioning ring 5.

The workpiece 4 transported by a transport device (not shown) first comes into contact with the tip of the suction tube 3 protruding outside the gripping claw 2, and is passed through the air suction passage U of 7 by a vacuum pump (not shown). By suctioning the workpiece 4 into the suction tube 3
Hold while suctioning.

Next, suction is further performed using a vacuum pump, and the suction cylinder 3 that has absorbed the workpiece 4 is pulled along the axis of the scroll chuck 1 against the force of the compression spring 9, so that the workpiece 4 is attached to the positioning ring 5. The workpiece 4 is moved until it abuts, and the workpiece 4 is held in that position. Further, when the suction cylinder is raised, the air suction passage (2) of 6 and the air suction passage (2) of 7 are connected to form a suction system for contact confirmation. At this time, the workpiece 4 is
Since the distal end portion is the elastic body 3a, it is held in contact with the elastic body 3a. Here, the reference plane of the positioning ring 5 and the workpiece 4
If something like a foreign object 8 is present between the workpieces 4 and the suction tube 3, and the workpiece 4 is not in accurate contact with the suction cylinder 3, the air suction passage I provided in the positioning ring 5 may be damaged as shown in the figure. A channel is formed into which the atmosphere flows, and the vacuum pressure of the air flowing into the air suction passage H at 7 is reduced. By comparing this decrease in vacuum pressure with the vacuum pressure during normal suction using a vacuum gauge (not shown), it is determined whether the workpiece 4 is in accurate contact with the positioning ring 5, and whether it is not in accurate contact with the positioning ring 5 or not. in case of,
After cleaning the abutment surface with a cleaning tool (not shown), repeat the abutment operation once again. If the abutment is accurate, close the gripping claws 2 of the scroll chuck 1 in the direction of arrow A in FIG. After machining, the workpiece 4 is returned to the conveying device by performing the process in reverse order.

Thereafter, the chuck and processing of the workpiece 4 can be continuously and automatically performed using the same method.

According to this embodiment, it is possible to determine whether the workpiece is accurately in contact with the reference surface, and highly accurate machining can be performed while avoiding distortion of the workpiece and variations in wall thickness.

Although a scroll chuck is used in this embodiment, a similar effect can be obtained by using something like a collet chuck.

(Second Embodiment) FIGS. 3(a) and 3(b) are a sectional view and a plan view showing a second embodiment of the chuck device of the present invention.

Each component is almost the same as the first embodiment, but a collet chuck 10 is used instead of the scroll chuck, and the air suction passage 6 is independent from the air suction passage 7, and the vacuum source is also It has a different configuration. Therefore, among the constituent elements, the same constituent elements as those in the first embodiment are given the same numbers and their explanations will be omitted.

The workpiece 4 that has been transported by a transport device (not shown) is first transferred to the suction cylinder 3 that protrudes outside the gripping claws 2.
The workpiece 4 is held in the suction tube 3 by contacting the tip elastic body 3a and suctioning from the air suction passage 7 by a vacuum pump (not shown).

Next, suction is further performed using a vacuum pump, and the suction cylinder 3 that has attracted the workpiece 4 is pulled along the axis of the collet chuck 1 against the force of the compression spring 9, so that the workpiece 4 is attached to the positioning ring 5. The workpiece 4 is moved until it comes into contact, and the workpiece 4 is held in that position.At this time, suction is applied from another vacuum source (not shown) connected to the air suction passage I of 6, and changes in vacuum pressure are observed with a vacuum gauge (not shown). By doing so, the workpiece 4
It is determined whether the positioning ring 5 is in accurate contact with the positioning ring 5. If the contact is not accurate, the vacuum gauge pressure has dropped, so after cleaning the contact surface with a cleaning tool (not shown), the contact operation is repeated once again. If the collet chuck 1 is in accurate contact, the gripping claws 2 of the collet chuck 1 are closed in the direction of arrow A in FIG. 3 to hold the workpiece 4 and perform machining. After processing, the workpiece 4 is returned to the transfer device by performing the reverse procedure to the above procedure.

According to this embodiment, as in the first embodiment, it is possible to determine whether the workpiece is accurately in contact with the reference surface, and high-precision machining can be performed while avoiding distortion of the workpiece and variations in wall thickness. I can do it. In addition, in this embodiment, since the workpiece suction system and the contact 61 suction system are independent, air pressure control is simpler than in the first embodiment, and a more reliable suction system is constructed. can do.

(Third Embodiment) FIGS. 4(a) and 4(b) are a sectional view and a plan view showing a third embodiment of the chuck device of the present invention.

Each component is almost the same as in the first embodiment, but the air suction passage (6) is independent from the air suction passage (7) and communicates with the outside. Therefore, similar components are given the same numbers and their explanations will be omitted.

In addition, a vacuum test tube 20 having a suction pad 20a at the tip
is so constructed that it can move from outside the scroll chuck 1 and come into contact with the position of the air suction passage I at 6. Also, instead of spring 9, scroll chuck 1
An air cylinder 11 is provided on the outside of the suction tube 3, and by connecting the rod lla with a connecting piece 3c protruding from the suction tube 3, the suction tube 3 is integrated with the suction tube 3, and the suction tube 3 can be moved up and down. ing.

Therefore, the workpiece 4 transported by a transport device (not shown) first passes through the suction tube 3 protruding from the gripping claw 2.
The workpiece 4 is held in the suction tube 3 by abutting against the tip elastic body 3a of the suction tube 3 and suctioning the workpiece 4 from the air suction passage 7 with a vacuum pump (not shown).

Next, by moving the rod lla of the air cylinder 11 upward, the suction cylinder 3 that has attracted the workpiece 4 is drawn along the axis of the scroll chuck 1, and the workpiece 4 is moved until it comes into contact with the positioning ring 5. and hold the workpiece 4 in that position.

The vacuum test tube 20, which had been located outside the scroll chuck l, is now located at the 6th position in the positioning ring 5.
Move to the position of the air suction passage I and come into contact with it.

Next, suction is applied from another vacuum source connected to the vacuum inspection tube 20, and by observing changes in vacuum pressure with a vacuum gauge (not shown), it is determined whether the workpiece 4 is in accurate contact with the positioning ring 5. .

If the contact is not accurate, the vacuum gauge pressure has dropped, so after cleaning the contact surface with a cleaning tool (not shown), the contact operation is repeated once again.

If the contact is accurate, the gripping claws 2 of the actuator 1 are closed to hold the workpiece 4 and process it.

After processing, the workpiece 4 is returned to the transport position by performing the reverse procedure to the above procedure.

According to this embodiment, as in the first embodiment, it is possible to judge whether the workpiece is accurately in contact with the reference surface, and it is possible to perform high-precision machining that avoids distortion of the workpiece and variations in wall thickness. can. In addition, in this embodiment, the suction system for contact confirmation is completely independent, and the air suction passage I can also be a simple through hole, so that the structure of the chuck device main body can be simplified. Furthermore, by moving the suction cylinder up and down using a means different from the suction means, the timing of suction of the workpiece and movement of the suction cylinder can be freely adjusted.

〔Effect of the invention〕

According to the present invention, it is possible to determine whether or not the workpiece is accurately in contact with the reference surface, and highly accurate machining can be performed while avoiding distortion and variation of the workpiece.

[Brief explanation of drawings]

FIG. 1 shows a conceptual diagram of the present invention, FIG. 1(a) is a sectional view, FIG. 1(b) is a plan view thereof, and FIG. 1(C) is an explanatory diagram showing a workpiece holding process. FIG. 2 is a sectional view showing the first embodiment of the chuck device of the present invention, FIGS. 3(a) and 0)) are sectional views and plan views showing the second embodiment, and FIGS. 4(a) and ( b) is a sectional view and a plan view showing the third embodiment;
FIGS. 5(a) and 5(b) are a sectional view and a partial plan view showing a conventional chuck device. 1...Actuator for opening/closing gripping claws 2...Gripping claws 3...Adsorption cylinder 4...Workpiece 5...Positioning ring 6...Air suction passage I 7...Air suction passage ■ 8 ...Foreign object 9...Spring 10...Collet chuck 11...Air cylinder 20...Vacuum inspection tube (0) (c) Figure (0) Figure (CI) Figure (b) ) (a) Figure

Claims (1)

[Claims] (1) A chuck device that grips a workpiece includes an actuator that grips the workpiece and has gripping claws that can be opened and closed, and is installed coaxially inside the actuator to attract the workpiece and move it in the axial direction. a suction cylinder having an elastic body at its tip; a ring provided coaxially with the actuator on the inside or outside of the suction cylinder, positioned in the thickness direction of the workpiece, and having a flow path through which fluid flows; A chuck device comprising means capable of moving in the axial direction of the actuator so that the workpiece suctioned by the suction tube comes into contact with the positioning ring.