JPH07266112A - Workpiece holding chuck - Google Patents

Abstract

PURPOSE:To hold a workpiece in a stable state to perform a high-accuracy machining. CONSTITUTION:Sliding holes 4 sloped toward the tip side of a chuck body 3 so that they can approach the axial direction, are drilled at equal intervals at four places around the shaft center of the chuck body 3. Jaw members 6a, 6b for holding the inside surface of a workpiece W are slidably installed in the respective sliding holes 4 respectively. The jaw members facing each other out of the respective jaw members 6a, 6b can be slid and driven by the same driving means.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a work holding chuck used for cutting the outer peripheral surface of a work.

[0002]

2. Description of the Related Art Conventionally, as a chuck for holding a workpiece,
There is one in which a claw member that can be opened / closed in a radial direction with respect to its axis is equally provided on the end surface of a cylindrical chuck body that is rotationally driven. With such a workpiece holding chuck,
Holding the work piece by simultaneously expanding the respective claw members in the radial direction by the same size and pressingly contacting the inner surface of the center hole of the work piece while the end surface of the work piece is in contact with the end surface of the chuck body. You can do it.

[0003]

However, in the conventional workpiece holding chuck described above, when the center hole of the workpiece held by the pawl member is, for example, a rectangular square hole, the pawl member has four holes. In the case of the equal parts, only the two facing ones are in pressure contact with the inner surface of the center hole of the work piece, and the other two are idle. In addition, even a square hole having a square shape cannot be accurately formed like a round hole, so that it may not be reliably held by each claw member.

Therefore, the holding state of the work is not stable,
For example, when cutting the outer peripheral surface of a work piece, the claw member must have high rigidity in order to increase the pressure contact force of the claw member that contributes to holding the work piece. In addition, the pressure contact force acting on the work piece acts unbalanced, and the work piece is held in a deformed state for machining,
The desired processing accuracy (roundness) cannot be obtained. Therefore, in view of the above problems, it is an object of the present invention to provide a workpiece holding chuck that holds a workpiece in a stable state and realizes highly accurate machining.

[0005]

In order to achieve the above object, according to the invention as set forth in claim 1, in the chuck main body, there are four locations around the axis of the chuck body in the axial direction toward the tip side of the chuck body. Sliding holes that are inclined so as to approach each other are equally drilled, and claw members for holding the inner surface of the workpiece are slidably arranged in the respective sliding holes, while Among them, those facing each other are slidably driven independently of each other.

According to the second aspect of the present invention, each of the driving means can be driven by a fluid supplied from an independent fluid supply circuit.

[0007]

According to the structure of the invention described in claim 1, when holding the workpiece, the pair of claw members which are separately driven by different driving means move to the inner surface of the workpiece by moving by appropriate dimensions. Pressure contact.

According to the configuration of the invention described in claim 2, the movement of each claw member is performed through the fluid supply circuit provided separately and independently, and the claw member driven corresponding to each fluid supply circuit is Hold the work piece with an appropriate pressure contact force that does not cause deformation.

[0009]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a cross-sectional view of a workpiece holding chuck according to the present embodiment, in which the upper half portion and the lower half portion respectively show orthogonal cross sections. This work holding chuck has a structure in which a chuck body 3 is screwed and fixed to a shaft body 1 which is rotationally driven, via a pedestal portion 2.

The chuck body 3 is composed of a first body 3a and a second body 3b. Sliding holes 4 are formed in the first body 3a in four equal parts from the tip side, and each sliding hole 4 is formed in the chuck body 3.
It is inclined so that it approaches the axial center gradually toward the tip of the. The first main body 3a is formed with a stepped accommodation hole 5 including a small inner diameter portion 5a and a large inner diameter portion 5b.
The sliding holes 4 communicate with each other.

Claw members 6a and 6b are slidably arranged in the respective sliding holes 4. As for the claw members 6a and 6b, those arranged at opposing positions are designed to operate independently, and those shown in the upper half of FIG. 1 (see FIG. 2).
Middle, left and right symmetrically arranged) are short-sized claw members 6a,
What is shown in the lower half (arranged vertically symmetrically in Fig. 2)
Is the long-dimension claw member 6b.

The claw members 6a, 6b are substantially cylindrical, and a notch recess 7 is formed in a portion located on the outer peripheral side of the chuck body 3, and a screw member 8 screwed into the chuck body 3 is formed therein.
The rotation of the claw members 6a and 6b is restricted by the position of the tip of the. The position of the screw member 8 is fixed by the fixing screw 8a after the position adjustment.

A work holding surface 9 is formed at the tip of each of the claw members 6a and 6b, and the short dimension claw member 6a and the long dimension claw member 6b at the opposing positions are parallel to each other. The workpiece holding surface 9 of the short-dimension claw member 6a is larger than the workpiece holding surface 9 of the long-dimension claw member 6b in the chuck body 3.
Is formed at a position close to the axis center of the two claw members 6a, 6
The workpiece W can be held only by moving b by substantially the same size.

Further, a locking recess 10a is formed on the rear end side of the short size pawl member 6a on the axial center side of the chuck body 3, and a chuck is formed on the rear end side of the long size pawl member 6b. A protruding portion 10b that protrudes to the outer peripheral side of the main body 3 is formed.

The short-dimension claw member 6a includes a driving member 11
It is designed to slide with. The drive member 11 includes a stepped drive receiving portion 12 and the drive receiving portion 1.
2 and an operating portion 13 screwed into a screw at the tip of the chuck body 2, and is slidably provided on the second main body 3b of the chuck main body 3. Specifically, the second main body 3b that constitutes the chuck main body 3
In the bearing hole 14 formed at the center of the
The sliding shaft 12a of the drive receiving portion 12 constituting the above is slidably positioned, and the piston portion 12b of the drive receiving portion 12 is positioned in the cylinder hole 15 having a diameter larger than the bearing hole 14.
As a result, first and second cylinder chambers 16 and 17 that communicate with the oil holes 2a and 2b formed from the pedestal portion 2 side are formed in the cylinder hole 15, respectively.
In addition, the operating portion 13 is provided with a locking portion 13a that is locked in the recess 10a of the short-dimension claw member 6a and integrally slides.

A drive ring 1 for driving the long-sized pawl member 6b is provided on the outer peripheral portion of the rear end side of the pawl members 6a and 6b.
9 are provided. The drive ring 19 has a stepped shape, and the small-diameter tubular portion 19a thereof has a small inner-diameter portion 5 of the accommodation hole 5.
The large-diameter cylindrical portion 19b is slidably positioned on the large-inner diameter portion 5b. Further, an annular stopper member 20 is provided at the rear end edge of the drive ring 19, and a coil spring 21 is equally divided into four between the stopper member 20 and the pedestal portion 2 to drive the drive ring 19. The long-dimension claw member 6b is urged through the ring 19 in the direction of protruding from the chuck body 3. Further, the projecting portion 10b of the long-dimension claw member 6b is located on the inner diameter side step portion of the drive ring 19, and the large-diameter tubular portion 19b is interposed via the holding ring 25a.
The locking ring 25b locked to the inner surface of the drive mechanism moves the long-dimension pawl member 6b integrally with the drive ring 19. Furthermore, the outer diameter side step portion of the drive ring 19 and the large inner diameter portion 5b and the small inner diameter portion 5a of the accommodation hole 5 form a third cylinder chamber 22. An oil hole 2c from the pedestal portion 2 side is communicated with the third cylinder chamber 22 so that the drive ring 19 can be retracted by the supplied air, oil or the like.

Reference numeral 23 is an adjusting screw, which is used for the pedestal portion 2, the second
It is used to adjust the displacement of the first main body 3a slidably attached to the main body 3b. That is, by rotating the adjusting screw 23, the amount of protrusion of the chuck body 3 into the large inner diameter portion 5b is adjusted, and the fitting gap formed between the first body 3a and the second body 3b is used. Then, the axis of the chuck body 3 is aligned with the regular position, and the chuck body 3 is fixed to the position with the tightening bolt 26. A ring-shaped support member 24 for abutting and positioning the end surface of the workpiece W is screwed to the front end surface of the chuck body 3.

In the work holding chuck having the above-described structure, when holding the work W, first, the claw members 6a and 6b are slid in a direction projecting from the chuck body 3 to move the work W to the axial center side. Keep it. Short size claw member 6a
Then, by supplying oil into the second cylinder chamber 17 through the oil hole 2b, the operation is performed through the driving member 11. On the other hand, in the long-dimension claw member 6b, the oil is discharged from the third cylinder chamber 22 through the oil hole 2c and the biasing force of the coil spring 21 is utilized to perform the driving through the drive ring 19.

Next, the workpiece W is placed on the outer circumference of the claw members 6a and 6b. In this case, as shown in FIG. 3, if the center hole of the workpiece W is substantially rectangular, the short-dimension claw member 6a is the long side edge L and the long-dimension claw member 6b is the short side edge S. While facing each other, the end surface of the workpiece W is brought into contact with the support member 24.

Then, by supplying oil to the first cylinder chamber 16 via the oil hole 2a, the short-dimension claw member 6a is retracted via the drive member 11, and at the same time, the third cylinder chamber is accommodated via the oil hole 2c. The oil is supplied to 22 and the long-dimension claw member 6b is passed through the drive ring 19.
Retreat. Each claw member 6a, 6b has an inclined sliding hole 4
The workpiece holding surface 9 moves inside and moves in the outer peripheral direction of the chuck body 3.

As a result, the short-dimension claw member 6a is pressed against the long-side inner surface L of the workpiece W, and the long-dimension claw member 6b is pressed against the short-side inner surface S. The pressure contact force is set by the fluid supplied from the supply circuit. Therefore, if the pressure contact force is the same as in the workpiece W having a rectangular hole shape, the workpiece W
Even if there is a risk of deformation, it is possible to hold it properly. However, if it is not necessary to consider the deformation of the workpiece W (for example, when a large holding force is not required), one fluid supply circuit is provided with the short dimension claw member 6a and the long dimension claw member 6b. It may be shared in.

In the above embodiment, the case where the hole shape of the workpiece W is held is described, but even if the hole shape is round, it can be held properly. A hole-shaped workpiece W in which there are pressure contact receiving portions for pressing the claw members 6a and 6b at symmetrical positions in the Y-axis direction.
If so, it is applicable.

[0023]

As is apparent from the above description, according to the workpiece holding chuck of the invention of claim 1,
By driving each claw member corresponding to the hole shape of the workpiece, all the claw members can be pressed against the inner surface of the workpiece, so that the holding state of the workpiece can be stabilized.

Further, according to the workpiece holding chuck of the second aspect of the invention, since the workpieces can be held by the different pressure contact forces between the facing claw members, the workpiece having a rectangular hole shape can be held. Even an object can be maintained in an appropriate holding state without being deformed.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a workpiece holding chuck according to this embodiment.

FIG. 2 is a front view of the tip of the claw member shown in FIG.

3 is a front view of a workpiece held by the workpiece holding chuck shown in FIG. 1. FIG.

[Explanation of symbols]

 3 ... Chuck body, 4 ... Sliding hole, 6a, 6b ... Claw member.

Claims (2)

[Claims] 1. A chuck body is provided with four slide holes, which are inclined about the axis of the chuck body so as to approach in the axial direction toward the tip side of the chuck body, at equal intervals. While the claw members for holding the inner surface of the workpiece are slidably arranged in the sliding holes, respectively, the claw members facing each other are independently slidably driven. Characteristic chuck for holding work. 2. The workpiece holding chuck according to claim 1, wherein each of the driving means can be driven by a fluid supplied from a separate and independent fluid supply circuit.