JP2510439B2 - Chuck - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a chuck used for machining.

[0002]

2. Description of the Related Art A tube for pumping air is attached to a base which is detachably attached to a spindle of a machine tool or a base which is attached to a fixed bed, and a passage opened to the outer surface of the base on the side opposite the spindle is attached A diaphragm which is provided in communication with the tube and has a thick edge portion and a plurality of work gripping claws projecting integrally on the outer surface of the thin portion is fixed to the edge portion of the outer surface of the base, and A work-holding jig for machining, that is, an air chuck in which the passage is exposed to a closed space between the outer surfaces of the base is disclosed in Japanese Utility Model Laid-Open No. 2-53313 and JP-A-2-269513.
No. 6,086,045.

[0003]

The air chuck pressurizes a plate-shaped diaphragm with air and deforms the diaphragm in the bending direction by the pressure of this air, and drives the work holding claw in the work holding or releasing direction. are doing.

Therefore, a large air pressure is required for the deformation of the diaphragm, a large air pressure feeding device or a pressure increasing valve is required, and there is a defect that the device becomes large and the cost is high. The present invention aims to eliminate the above defects.

[0005]

In order to achieve the above object, the present invention has a main body 1 which is detachably mounted on a spindle or the like of a machine tool and has a cylinder wall 1a formed on an inner diameter portion thereof, and slides on the cylinder wall 1a. A piston 8 freely fitted and arranged, a cylindrical body 3 fixed to the main body 1 that axially slidably supports an inner diameter portion of the piston 8, and a fluid is pumped to both sides of the piston 8. A fluid tube 4 rotatably mounted on the cylindrical body 3 via ball bearings 21 and 21a, and a body tube whose outer diameter portion is bent so as to be pre-compressed in a diameter reducing direction and have a stable state in two directions. 1, an operating plate 16 having a central portion coupled to the piston 8 and a work holding claw 17 provided on the operating plate 16,
18 and.

[0006]

The gripping force of the work is determined by the elastic force of the operating plate 16 in the bending direction. Deformation of the working plate 16 in the work gripping direction or the work gripping releasing direction drives the piston 28 by fluid pressure to deform the working plate 16 from one curved state to the neutral state. The working plate 16 is
With this neutral state as a boundary, if you exceed this even a little,
It bends to the other side by its own elasticity, and the work gripping claw 1
7 and 18 are displaced in the workpiece gripping or gripping releasing direction.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of the present invention will be described below in detail with reference to the embodiments shown in the accompanying drawings. Reference numeral 1 denotes a cylinder body detachably attached to an end surface of a spindle of a machine tool, a base 1c having a cylinder wall 1a formed on a cylinder portion, and a disc-shaped base fixed to an end portion of the cylinder portion of the base 1c. It is composed of a cover 1b. A piston housing space is formed between the base 1c and the base cover 1b.

Reference numeral 3 designates the base cover 1 whose flange portion is screwed.
It is a cylindrical body fixed to b and is loosely fitted and arranged in a hole formed in the central portion of the base 1c and the base cover 1b. In the inner diameter portion of the cylindrical body 3, a ball bearing 21,
The inner cylinder 7 is rotatably fitted and arranged via 21a so as not to move in the axial direction.

Reference numeral 4 denotes a fluid tube, which is an outer cylindrical portion 4a.
And a triple structure of the inner tubular portion 4b and the inner tubular portion 4c,
A threaded portion formed on the outer peripheral surface of the outer tubular portion 4a is screwed into a threaded portion formed on the inner diameter portion of the inner tube 7 in a sealed manner.

The inner cylindrical portion 4c has the cylindrical portion 4a,
4b, and the tip of the tubular portion 4c is open to the chuck portion. A space portion between the inner peripheral surface of the outer tubular portion 4a and the outer peripheral surface of the middle tubular portion 4b constitutes a first fluid pressure feeding path 5, and the space between the inner peripheral surface of the inner tubular portion 4b and A second fluid pressure feeding path 6 is formed between the inner cylindrical portion 4c and the outer peripheral surface thereof. The fluid pressure feeding paths 5 and 6 communicate with a fluid pressure feeding device (not shown) including an air pressure feeding device. An oil passage is formed inside the inner cylindrical portion 4c.

Reference numeral 8 denotes a piston, the outer peripheral surface of which is slidably fitted in a cylinder wall 1a of the cylindrical portion of the base 1c in a sealed manner. The space portion in contact with one surface of the piston 8 is formed through the through hole 9 formed in the cylindrical portion 8a of the piston 8, the circumferential groove 9a communicating with the through hole 9, and the peripheral wall of the cylindrical body 3. Through hole 10, circumferential groove 10 communicating with the through hole 10
a, a through hole 13 provided through the inner cylinder 7, a circumferential groove 13a communicating with the through hole 13, and a through hole 1 provided through the outer tubular portion 4a.
1 to communicate with the first fluid pressure feeding path 5.

A space portion in contact with the other surface of the piston 8 has a through hole 12 formed in the cylindrical portion 8a of the piston 8, a circumferential groove 12a communicating with the through hole 12, and a transparent portion in the cylindrical body 3. The through hole 13, the circumferential groove 13a communicating with the through hole 13, and the through hole 21 that is provided through the inner cylinder 7 through the second hole.
To the fluid pressure feeding path 6. The peripheral wall of the cylindrical portion 8a formed integrally with the piston 8 is sealed in ring-shaped guide holes 14 and 15 formed between the base 1c and the cylindrical body 3 and between the base cover 1b and the cylindrical body 3, respectively. Like
It is fitted slidably along the axial direction.

Reference numeral 16 is a plate-shaped operating plate made of a stainless steel plate or other thin metal plate having elasticity and strength, and a plurality of workpiece holding claws 17 and 18 are integrally provided on the operating plate. A hole is formed in the central portion of the operating plate 16, and a thick portion is formed in the vicinity of the hole. The central portion of the operating plate 16 is slidably fitted to the small diameter portion of the cylinder tubular portion 8a,
The thick portion is formed by the nut 20 and the piston 8 cylinder portion 8
It is fixed to the end face of a.

Reference numeral 19 is a mounting ring, and a fitting recess 19a is formed on the entire inner circumference of the mounting ring. The diameter of the peripheral surface of the fitting recess 19a is set to be smaller than the outer diameter of the operating plate 16. In this embodiment, the fitting recess 1
The diameter of the peripheral surface of 9a is 78 millimeters, and the outer diameter of the working plate 16 is set to 78,1 millimeters.

The outer peripheral end of the operating plate 16 is press-fitted into the fitting recess 19a of the mounting ring 19, and in this state the mounting ring 19 is fixed to the outer surface of the base 1c by bolts. With the mounting ring 19 fixed to the base 1c, the base 1c of the mounting ring 19 is
By the fixing force against the outer diameter portion of the operating plate 16, the outer diameter portion of the operating plate 16 is tightly pressed by the surface 19b perpendicular to the axial direction of the mounting ring 19 and the end surface of the tubular portion of the base 1c, and the operating pressure is actuated by the clamping force. The outer diameter portion of the plate 16 is fixed to the end surface of the tubular portion 2a of the base 1c. 27 is a Teflon washer.

The actuating plate 16 is bent in either the left or right direction by the pressure in the diameter reducing direction from the fitting recess 19a of the mounting ring 19 as shown in FIG. In the present embodiment, this bending amount is 0,
7 mm. When pressure is applied to the center of the operating plate 16 in the rightward direction from the leftward curved stable state shown by the solid line in FIG. 3, the elastic force of the operating plate 16 does not depend on the external pressure and delimits the boundary point, that is, the flat plate shape. As shown by the dotted line in Fig. 3, it bends to the right and stabilizes. The same applies to the case where the rightward curved stable state is changed to the leftward curved stable state.

Next, the operation of this embodiment will be described. In FIG. 2, when the operating plate 16 is bent to the left, the work gripping claws 17 and 18 are expanded, and when the operating plate 16 is bent to the right, the work gripping claws 17 and 18 are opened.
18 is reduced. Expansion of the work gripping claws 17 and 18,
By the reduction, the work gripping claws 17 and 18 strongly grip the work (not shown) or release the grip. When it is desired to bend the operating plate 16 from the right bent state in FIG. 2 to the left bent direction, in FIG. 1, air is supplied from the first fluid pressure feeding path 5 to the through holes 11, 13, 10, 9 in FIG. Through the piston 8 to the space portion in contact with the right side surface in FIG. 1, and remove the air in the space portion in contact with the left side surface of the piston 8,
The piston 8 is driven leftward in FIG. 1 by the pressure of air until it is locked by the stopper surface 2b of the base cover 2.

When the piston 8 moves to the left, the central portion of the working plate 16 interlocked with the piston 8 is pushed to the left by the piston 8. The operating plate 16 is a flat plate shown in FIG.
When the piston 8 is further pushed to the left, the bending direction is changed, and the operating plate 16 is bent to the left as shown in FIG. 2 by its own elasticity. Therefore, the pressure of the air in the piston housing space may be such that the actuating plate 16 is displaced from its rightward bent state to a substantially neutral state, and the actuating plate 16 is bent leftward from its neutral state. It is not the pressure of the air in the piston storage space, but the urging force of the working plate 16 itself based on the diameter-reduced pre-compression state of the working plate 16.

In order to bend the actuating plate 16 from the state in which it is bent to the left in FIG. 2 to the right, the through holes 21, 13,
The air in the air chamber in contact with the right side surface of the piston 8 is evacuated while the air is pumped to the air chamber in contact with the left side surface of the piston 8 through 12, and the piston 8 is moved to the right by the stopper surface 1b of the base 1. Drive until you hit. The operating plate 16 is displaced from the leftward curved stable state to the neutral state shown in FIG. 1 by the driving force from the piston 8 in the right direction, and this neutral state is used as a conversion point, and slightly above the conversion point in the right direction. And the elastic force of the operating plate 16 itself causes it to bend to the right and stabilize. The rotation of the main body 1 is performed around the inner cylinder 7, and the tube 4 is held in a non-rotating state.

[0020]

Since the present invention is configured as described above, the working plate can be driven with a small fluid pressure, and the work can be strongly gripped. Further, during rotation of the main body,
The tube can be held non-rotating and the tu
Do not move the valve together with the piston back and forth.
There is an effect that can do.

[Brief description of drawings]

FIG. 1 is a sectional view showing a preferred embodiment of the present invention.

FIG. 2 is an explanatory diagram of the present invention.

FIG. 3 is an operation explanatory view of an operating plate.

[Explanation with reference numerals] 1 base 1a cylinder wall 2 base cover 3 cylinder body 4 fluid tube 5 fluid pressure feed path 6 fluid pressure feed path 7 work stopper 8 piston 8a piston cylinder portion 9 through hole 10 through hole 11 through hole 12 through hole 13 through Hole 14 Guide hole 15 Guide hole 16 Actuating plate 17 Work gripping claw 18 Work gripping claw 19 Mounting ring 19a Fitting recess 21 Ball bearing 21a Ball bearing

Claims (2)

(57) [Claims] 1. A main body 1 which is detachably attached to a spindle or the like of a machine tool and has a cylinder wall 1a formed in an inner diameter portion thereof,
A piston 8 slidably fitted to the cylinder wall 1a, a cylindrical body 3 fixedly mounted on the main body 1 for axially slidably supporting an inner diameter portion of the piston 8, and the cylindrical body 3. axial direction through the ball bearings 21,21a
Rotatably mounted so as not to move in the direction, the piston
Through the through holes so that the fluid can be pumped to both sides of
The fluid tube 4 communicating with the inner diameter portion of the main body 1 is bent so as to be pre-compressed in the diameter reducing direction and has a stable state in two directions, the outer diameter portion is fixed to the body 1, and the central portion is An operating plate 16 connected to the piston 8 and the operating plate 1
A chuck comprising: workpiece gripping claws 17 and 18 provided on the chuck 6. 2. The chuck according to claim 1, wherein air is used as a pressure-feeding medium for the fluid tube 4, and the piston 8 is driven by the pressure of the air.