JPH05345207A - Chuck device - Google Patents

Abstract

PURPOSE:To provide a chuck device for eliminating the pressure-increasing and pressure-proof measures for equipment, by gripping an article-to-be-gripped by small fluid pressure. CONSTITUTION:A thin wall thickness plate 20 is provided on a chuck body 11, and plural grip nails 27 are protrudedly provided on the outer surface of the thin wall thickness plate 20. Plural pistons 24 and 25 are arranged, while being connected to the thin thickness plate 20, in the chuck body 11. Plural pistons 24 and 25 are concurrently moved by supplying fluid pressure such as air to bend the thin thickness plate 20. The gripping nails 27 are opened/ closed by bending the thin thickness plate 20 to mount/demount an article-to-be- gripped W between the gripping nails 27.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chuck device used for gripping an object to be gripped such as a work in a machine tool or the like.

[0002]

2. Description of the Related Art As a conventional chuck device of this type,
For example, it is shown in FIGS. 7 and 8 of Japanese Utility Model Application Laid-Open No. 2-53313. In this conventional device, a plurality of jaws are provided on the outer surface of a disk-shaped chuck body so as to be slidable in the radial direction, and a piston that is operated by fluid pressure is provided inside the chuck body. By the operation of this piston, the jaw is slid through the actuator and the screw engaging portion, and the object to be grasped is grasped.

However, in this conventional chuck device, the object to be grasped is gripped by sliding the jaws as described above. Therefore, the sliding portion is easily worn and poor in durability, and the sliding portion of the jaw is easily clogged with chips and the like, and it is necessary to regularly perform maintenance such as removal of chips. Moreover, since the three jaws are radially arranged on the outer surface of the chuck body, there is a problem that it is difficult to maintain the dynamic balance when the chuck body rotates at a high speed.

In order to deal with such a problem, for example, the structure shown in FIGS. 1 to 6 of Japanese Utility Model Laid-Open No. 2-53313 has been proposed. In this structure, a thin plate is provided on the chuck body, and a plurality of gripping claws are provided on the outer surface of the thin plate in a protruding manner. Then, by applying fluid pressure to the closed space inside the thin plate, the thin plate is bent and the gripping claws are opened and closed, so that the object to be gripped is attached and detached.

Further, a thin plate is provided on the chuck body, a plurality of gripping claws are provided on the outer surface of the thin plate, and one piston is arranged in contact with the thin plate inside the chuck body. Devices have also been proposed in the past. In this device, by operating the piston with fluid pressure, the thin plate is bent to open and close the grasping claws, and the object to be grasped is attached and detached.

[0006]

However, in these conventional apparatuses, the thin plate does not vibrate violently when the chuck body is rotated at a high speed while the object to be grasped such as the work is grasped by the grasping claws. As described above, it is necessary to make the thin plate thick enough to resist centrifugal force and the like. Therefore, a large fluid pressure is required to bend the thin plate. Therefore, in a general factory or the like where low-pressure fluid pressure piping is performed, it is necessary to install a pressure booster or strengthen the piping structure, which causes a problem of enormous equipment cost.

Further, particularly in the former conventional device, a fluid pressure is supplied to the closed space inside the chuck body so that a large fluid pressure is directly applied to the thin plate, so that the thin plate is cracked or the like. There is also a problem of danger that an explosion will occur when fluid pressure is supplied to the closed space.

The present invention has been made by paying attention to the problems existing in such a conventional technique, and the purpose thereof is to secure an object to be grasped without using a large fluid pressure. It is possible to hold the device in place, and it is possible to eliminate the need for pressure increase measures and pressure resistance measures for the equipment, and it is possible to prevent the device from exploding during the holding operation, and also to increase the operating stroke of the holding claw. (EN) Provided is a chuck device capable of adjusting a gripping force easily.

[0009]

In order to achieve the above object, according to the present invention, a thin plate is provided on a chuck body, and a plurality of gripping claws are provided on the outer surface of the thin plate so as to bend the thin plate. In a chuck device in which a gripping claw is opened and closed by bending to attach and detach an object to be gripped, a plurality of pistons are arranged in the chuck body so as to be connected to a thin plate,
The thin plate is bent by simultaneously moving the pistons by fluid pressure.

[0010]

In the chuck device constructed as described above, when fluid pressure is applied to a plurality of pistons, the pistons are simultaneously moved and the thin plate is bent. As a result, the grip claws on the outer surface of the thin plate are opened or closed, and the object to be gripped is gripped or released between the grip claws.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a chuck device embodying the present invention will be described in detail below with reference to the drawings.

As shown in FIG. 2, a spindle 1 is rotatably supported by a machine frame 2, and a chuck device 3 for gripping a work W as an object to be gripped is attached to an end of the spindle 1 via an adapter 4. ing. The pulley 5 is fixed to the base end of the spindle 1, and the spindle 1 is rotated at high speed via the pulley 5 by the rotation of a motor (not shown). The rotary journal 6 is provided on the base end side of the spindle 1 and is connected to the chuck device 3 via a connecting pipe 7. From the air supply port 8 and the coolant supply port 9 of the rotary journal 6, air as a driving fluid, coolant and air blow are supplied to the chuck device 3 through the connecting pipe 7.

Therefore, the structure of the chuck device 3 will be described in detail. As shown in FIGS. 1 and 3, the chuck body 11 is formed in a disk shape, and two cylinder chambers 12 and 13 are axially formed therein. Are formed side by side. The back cover 14 is joined and fixed to the base end surface of the chuck body 11, and the shaft portion 1 connected to the connecting pipe 7 is provided at the center thereof.
5 are provided. The air passage 16 is the back cover 14
Further, the air formed in the chuck body 11 and supplied through the connecting pipe 7 is introduced into both the cylinder chambers 12 and 13 through the air passage 16.

The jet port 17 is formed at the center of the shaft portion 15, and a female screw portion 18 is provided at the center thereof. When the work W has a columnar shape as shown in FIG. 1, the work holder 19 is screwed into the female screw portion 18 of the ejection port 17, and the work W is held at the tip of the work holder 19. .. Further, as shown in FIG. 4, when the work W has a cylindrical shape with the flange portion F, the coolant and the air blow supplied through the connecting pipe 7 are ejected from the ejection port 17 toward the work W. ..

The thin plate 20 is fixed to the tip surface of the chuck body 11 by a plurality of screws 22 at the peripheral thick flange portion 21, and a plurality of mounting pedestals 2 are provided on the central outer surface thereof.
3 are arranged so as to project on the same circumference. The two pistons 24 and 25 are movably arranged in the cylinder chambers 12 and 13, and a cylindrical shaft portion 26 that is sequentially connected to the thin plate 20 is provided at the center thereof. And the cylinder chamber 12,
When the pistons 24 and 25 are moved toward the tip end side of the chuck body 11 by supplying air into the cylindrical shaft portion 2,
The thin plate 20 is bent outwardly via 6.

While the plurality of gripping claws 27 are connected to each other in a ring shape by a connecting body 28, the thin plate 2 is connected by screws 29.
It is fixed to each of the 0 mounting bases 23. When the thin plate 20 is bent by the movement of the pistons 24 and 25, the grip claw 27 is opened to release the grip of the work W, and when the thin plate 20 returns to the original state, the grip claw 27 is released. Is closed and the work W is gripped.

A plurality of screw holes 30 are formed in the thick flange portion 21 of the thin plate 20 at predetermined intervals. Then, as shown in FIG. 4, when gripping a cylindrical work W having a flange portion F, by screwing a screw 31 into the screw hole 30, the outer surface of the thick flange portion 21 is By attaching the holder 32 and bringing the outer peripheral portion F of the work W into contact with the holder 32, even if the work W is large, the work W is supported in a state in which vibration and the like during high-speed rotation are prevented.

As shown in FIGS. 1 and 3, a plurality of screw holes 33 are formed on the outer periphery of the chuck body 11 at predetermined intervals, and adjusting screws 34 are screwed into the screw holes 33, respectively. Then, by changing the screwing amount of the adjusting screw 34, it is possible to adjust the dynamic balance when the chuck device 3 rotates.

Next, the operation of the chuck device configured as described above will be described. Now, in this chuck device, from the air supply port 8 of the rotary journal 6 to the connecting pipe 7
Through the cylinder chambers 12, 13 in the chuck body 11
When air of a predetermined pressure is supplied to the pistons 24 and 25, the pistons 24 and 25 are simultaneously moved to the tip end side of the cylinder body 11, and the thin plate 20 is bent outward. As a result, the plurality of grip claws 27 are released from the closed state.

In this state, as shown in FIG. 1 or 4,
The work W is inserted between the grip claws 27, and the work holder 19
Alternatively, it is brought into contact with the flange holder 32. After that, when the supply of air to the cylinder chambers 12 and 13 is stopped, the thin plate 20 is returned from the bent state to the original state by the restoring force of itself, and the pistons 24 and 25 are moved to the original positions. Thereby, the plurality of gripping claws 27 are closed and the work W is gripped between the gripping claws 27.

As described above, in the chuck device of this embodiment, the two pistons 24, 2 are supplied with the supply of air.
5 is moved at the same time, and the thin plate 20 is bent by the combined movement force thereof. Therefore, the thin plate is bent by directly applying air pressure to the thin plate. The air pressure can be halved as compared with a conventional device or a conventional device configured to bend a thin plate by applying air pressure to one piston. Therefore, even when it is carried out in a general factory where low-pressure air piping is performed, there is no need to install a pressure booster or strengthen the piping structure, and the equipment cost can be reduced.

Further, in the chuck device of this embodiment, since the air pressure does not act directly on the thin plate 20, the thin plate 20
Even if cracks occur in the device, there is no danger of the device exploding when air is supplied. Further, in the device of this embodiment, since the air pressure is low, the operating stroke of the gripping pawl 27 can be increased by changing the air pressure to increase the movement amount of the pistons 24, 25.
Therefore, the grip force of the grip claw 27 can be easily adjusted by changing the air pressure.

The present invention is not limited to the configuration of the above-described embodiment. For example, the number of pistons may be changed to three or more, or hydraulic pressure may be used as fluid pressure. The configurations of the respective units can be arbitrarily modified and embodied without departing from the spirit of the invention.

[0024]

Since the present invention is configured as described above, the object to be grasped can be reliably gripped without using a large fluid pressure, and the equipment pressure increase countermeasure and pressure resistance countermeasure can be taken. Can be eliminated, the device can be prevented from exploding during the gripping operation, and the operating stroke of the gripping claw can be increased, so that the gripping force can be easily adjusted. It has an excellent effect.

[Brief description of drawings]

FIG. 1 is a partial sectional view showing an embodiment of a chuck device embodying the present invention.

FIG. 2 is a front view showing an entire spindle unit including the chuck device.

FIG. 3 is a partially cutaway side view of the chuck device.

FIG. 4 is a partially cutaway front view showing a state in which workpieces of different shapes are mounted on the chuck device.

[Explanation of symbols]

3 ... Chuck device, 11 ... Chuck body, 12 ... Cylinder chamber, 13 ... Cylinder chamber, 20 ... Thin plate, 24 ... Piston, 25 ... Piston, 27 ... Gripping claw, W ... Work as an object to be grasped.

Claims (1)

[Claims] 1. A chuck body is provided with a thin plate, a plurality of gripping claws are provided on the outer surface of the thin plate, and the gripping claws are opened and closed by bending the thin plate so that an object to be gripped can be attached and detached. In the chuck device described above, a plurality of pistons are arranged in the chuck body so as to be connected to the thin plate, and the pistons are simultaneously moved by fluid pressure to bend the thin plate. Chuck device.