JP4806472B1 - Chuck device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a chuck device capable of processing a thin workpiece by suppressing distortion and chatter during processing.
SOLUTION: Three or more clamping means for clamping both surfaces of a workpiece, a table for fixing the clamping means, a first contact means for contacting one surface of both surfaces of the workpiece, Second contact means that contacts the other surface at a position facing the first contact means, and the action of pressure acting on the work from the first contact means in a state where each of the gripping means holds the work. Each clamping means is arranged so that the direction is inclined to the machining reference position side of the workpiece with respect to a plane perpendicular to the rotation axis of the workpiece, and excessive stress or strain is not generated in the workpiece between adjacent clamping means. Secure to the table.
[Selection] Figure 1

Description

  The present invention mainly relates to a chuck device for chucking a thin workpiece.

Conventionally, when a workpiece is turned into, for example, a cylindrical shape with a desired thickness using a chuck device, the workpiece is strained or vibrated by gripping the outer periphery or inner periphery of the workpiece with a plurality of claws (so-called The occurrence of chatter is suppressed as much as possible.
For example, as shown in FIG. 10, the chuck device described in Patent Document 1 has a large number of cylinders 7 arranged at a high density on the outer peripheral wall of the chuck body 1 fixed to the main spindle of a lathe. The gripping claw 13 is fixed. And each piston 10 is advanced and retracted with the fluid pressure and the spring.
Further, since the center part of the work is grasped by the collet chuck 26 and the rear part of the work is supported by the work stopper 5, a lathe can be accurately processed even for a thin and easily distorted work. FIG. 11 shows a configuration in which the inner peripheral wall of the work is grasped by the cylinder 65 and the piston 66 and the outer peripheral wall is supported by the work stopper 64.

In addition, when the workpiece is clamped and fixed with a chuck device or a vise, the workpiece may be lifted from the processing reference position due to the action of the pressure during fixing. It may be struck with the reference plate and stuck to the reference plate. However, in a lathe chuck device where it is difficult to visually check the machining reference position, the work of bringing the workpiece into close contact with the reference plate relies on the operator's intuition, so there is a risk that the tapping work with a wooden hammer or the like may lack certainty. It was.
Therefore, for example, as shown in FIG. 12, the clamping device described in Patent Document 2 includes the clamping unit 2 that is slidably supported on the front surface of the support unit 3 in the vertical direction. The upper part of the surface is inclined forward (work 7 side). Thereby, when the workpiece 7 is clamped, a force acts so as to press the workpiece 7 against the reference plate 27 from the clamping portion 2 to the workpiece 7. Therefore, since the workpiece 7 is clamped in a state of being in close contact with the reference plate 27, the processing accuracy can be improved.
FIG. 13 shows a configuration in which the clamping device is applied to a lathe chuck.

JP 7-256505 A JP 2003-181732 A

However, even when the above-described conventional technology is used, a lathe is used to process the workpiece into a thin, large and large cylindrical shape (for example, a cylinder having a diameter of 200 mm, a length of 200 mm, and a thickness of about 2 mm using carbon steel). When processing is attempted, cutting can be performed up to a thickness of about 5.0 mm, but if the thickness is less than that, there is a problem that the workpiece is distorted or chattered.
Usually, in order to produce a thin, large, large-diameter cylinder, rolling and welding processes are combined, or lathe processing and polishing processes are combined, so the processing takes time and the production efficiency is poor. was there.

  In view of such a problem, an object of the present invention is to provide a chuck device that can process a thin workpiece by suppressing distortion and chatter during processing.

The chuck device of the present invention comprises three or more clamping means for clamping both the inner and outer surfaces of a hollow workpiece and a table for fixing the clamping means, and the clamping means contacts one of the inner and outer surfaces of the workpiece. A first contact means; and a second contact means that is in contact with a position opposite to the first contact means on the other surface of the workpiece. The acting direction of the pressure acting on the workpiece is inclined toward the machining reference position side of the workpiece with respect to the plane perpendicular to the rotation axis of the workpiece, and no excessive stress or distortion is generated in the workpiece between adjacent clamping means. Thus, each clamping means is fixed to a table.
Further, in the state where each clamping means clamps the workpiece, the shape of at least one of the first contact means and the contact surface of the workpiece and the shape of the second contact means and the contact surface of the workpiece are linear. It is characterized by that.
The first contact means includes a fixed portion, a bolt that is pivotally supported by the fixed portion so as to be pivotable about an axis, and a pad that is supported by the tip of the bolt and contacts the workpiece. It is characterized by constituting a swivel mechanism.
Further, in a state where each clamping means clamps the workpiece, the direction of the pressure acting on the workpiece from the first contact means is inclined at an acute angle toward the machining reference position side of the workpiece with respect to the plane perpendicular to the rotation axis of the workpiece. It is characterized by being.
Further, the workpiece is a thin cylindrical shape.

The present invention uses a plurality of clamping means to clamp a plurality of hollow workpieces from both the inside and outside surfaces, and prevents each workpiece from being excessively stressed or distorted between adjacent clamping means. By fixing, various processes such as cutting can be performed in a state in which stress and strain generated in the work are minimized. As a result, it has become possible to process thin-walled members, which was difficult with metal processing using a conventional chuck device.
When the chuck device of the present invention is used for cutting, for example, a carbon steel workpiece can be processed into a thin cylinder having a diameter of 200 mm, a length of 200 mm, and a thickness of about 2 mm.
In particular, by bringing the clamping means into contact with both sides of the workpiece so that the contact surface has a linear shape, even when the workpiece is rotated about its axis during the machining operation, most of the fine vibration transmitted from the rotating table is reduced. Vibrations absorbed by the clamping means and transmitted to the workpiece can be greatly suppressed. As a result, distortion and chatter during machining operations are suppressed, and it has become possible to machine a workpiece with a thickness that has not been able to be machined conventionally.
In this specification, “the shape of the contact surface is linear” means that when the contact surface is a square shape, the long side of the contact surface extends in the axial direction of the workpiece, and the contact surface is elliptical In this case, it is assumed that the long axis of the contact surface extends in the axial direction of the workpiece.

It is a perspective view which shows a chuck device. It is a principal part enlarged view which shows a clamping state It is a longitudinal cross-sectional view which shows the structure of a clamping means It is a top view which shows a clamping means. It is a top view which shows a table FIG. 6 is a sectional view taken along line AA of FIG. It is a longitudinal cross-sectional view which shows the state which fixed the clamping means to the table. It is a perspective view which shows the state which the 2nd contact means contacted the workpiece | work inner surface. It is a longitudinal cross-sectional view which shows the state with which the chuck device clamped the workpiece | work. It is a figure which shows the chuck device of patent document 1. It is a figure which shows the chuck device of patent document 1. It is a figure which shows the clamping apparatus of patent document 2 It is a figure which shows the clamping apparatus of patent document 2

[First embodiment]
A first embodiment of the chuck device 10 of the present invention will be described.
As shown in FIGS. 1 to 3, the chuck device 10 according to the present embodiment includes a clamping unit 20 and a table 30.
The clamping means 20 is a member for clamping both the inner and outer surfaces of the workpiece W, and is generally composed of a first contact means 40, a second contact means 50, and a connecting portion 60. The first contact means 40 and the second contact means 50 are joined to the connecting portion 60, and the workpiece holding opening 21 is formed by the first contact means 40, the second contact means 50 and the connecting portion 60.
The first contact means 40 is a member that comes into contact with one of the inner and outer surfaces of the workpiece W (the surface in the present embodiment), and includes a fixing portion 41, a bolt 42, and a pad 43.

The fixing portion 41 is a substantially rectangular parallelepiped metal member, and has a screw hole 44 extending in the front-rear direction. When the male screw portion of the bolt 42 is screwed into the female screw portion formed on the inner peripheral surface of the screw hole 44, the bolt 42 is pivotally supported by the fixing portion 41 so as to be pivotable around the axis, and is relatively relative to the fixing portion 41. It can move back and forth in the axial direction.
The pad 43 is supported by the tip of the bolt 42 on the back side thereof, and has a structure that can pivot around the supported portion. That is, the bolt 42 and the pad 43 constitute a swivel mechanism, and come into contact with the outer surface of the workpiece W on the surface side of the pad 43. When the workpiece W has a cylindrical shape, the contact surface between the pad 43 and the workpiece W has a linear shape extending in the vertical direction.
Further, since the screw hole 44 of the fixing portion 41 is formed so as to be inclined downward by about θ = 5 degrees with respect to the horizontal plane H from the rear to the front, the bolt 42 screwed into the screw hole 44 also has its tip. The side is inclined about 5 degrees with respect to the horizontal plane H. Thereby, although detailed description will be given later, a plane in which the direction of the pressure acting on the workpiece W from the surface of the pad 43 is perpendicular to the rotation axis L of the workpiece W in the state where the clamping means 20 clamps the workpiece W (this embodiment) In the embodiment, the workpiece W is inclined to the processing reference position side (downward in the present embodiment) with respect to the horizontal plane H).

The second contact means 50 is a member that is in contact with a position opposite to the first contact means 40 on the other surface (inner surface in the present embodiment) of the workpiece W.
Specifically, the second contact means 50 is a substantially rectangular parallelepiped metal member, and is joined to the rear end of the connecting portion 60 at the lower part. Further, since the front end of the connecting portion 60 is joined to the first contact means 40, the clamping means 20 is substantially U-shaped in a side view by the first contact means 40, the second contact means 50 and the connecting portion 60. . As a result, the first contact means 40 and the second contact means 50 are in contact with the opposing positions on the outer and inner surfaces of the workpiece W. The first contact means 40, the second contact means 50, and the connecting portion 60 may be integrally formed.
A screw hole 61 for fixing the clamping means 20 to the table 30 is formed on the lower surface of the connecting portion 60.
As shown in FIG. 4, the surface 51 of the second contact means 50, that is, the surface forming the workpiece clamping opening 21 has an arc shape that rises toward the center when viewed in plan. When the workpiece W has a cylindrical shape, the radius of the arc-shaped surface 51 is preferably smaller than the radius of the workpiece W, so that when the arc-shaped surface 51 is brought into contact with the inner surface of the workpiece W, the contact surface It is because it can be made into the line shape extended up and down.

The table 30 is a circular member for mounting and fixing a plurality of clamping means 20 on the upper surface thereof. The upper surface of the table 30 is horizontal and is orthogonal to the rotation axis L of the workpiece W.
As shown in FIGS. 5 and 6, a plurality of positioning openings 31 are formed in the table 30 radially so as to penetrate in the vertical direction and extend in the radial direction with a predetermined length. Then, as shown in FIG. 7, with the positioning opening 31 and the screw hole 61 of the connecting portion 60 aligned, the clamping means fixing bolt 32 is inserted from below the table 30 with a washer interposed therebetween. Each clamping means 20 is moved from the center of the table 30 in the radial direction, and is fixed to the table 30 with its position adjusted.
A rotation drive device 33 is attached to the lower part of the table 30, and the table 30 can be rotated around the rotation axis L by driving the rotation drive device 33.

Next, a method of using the chuck device 10 will be described.
First, each clamping means 20 is arranged on the table 30. In this state, the clamping means fixing bolt 32 is merely inserted into the screw hole 61 of the connecting portion 60 and the positioning opening 31 of the table 30, and the clamping means 20 is not fixed to the table 30.
Next, the workpiece W is inserted into the workpiece clamping opening 21 of the clamping means 20.
Next, each clamping means 20 is moved radially outward of the table 30 to bring the surface 51 of the second contact means 50 into contact with the inner surface of the workpiece W, as shown in FIG.
Next, the bolt 42 of each clamping means 20 is turned to move the pad 43 forward, and lightly contact the surface of the workpiece W. In this state, the clamping means 20 does not completely clamp the workpiece W.
Next, the rotation driving device 33 is driven to rotate the table 30 to rotate the workpiece W around the rotation axis L and adjust the position of the clamping means 20 as appropriate to perform the centering operation of the workpiece W.

After the work W has been centered, the bolt 42 of the holding means 20 is moved further forward so that the pad 43 is brought into strong contact with the surface of the work W and the work W is completely held.
In this state, the acting direction of the pressure acting on the surface of the workpiece W via the pad 43 is inclined about 5 degrees toward the machining reference position side of the workpiece W with respect to a plane (horizontal plane H) orthogonal to the rotation axis L of the workpiece W. is doing. By doing in this way, it can prevent that the workpiece | work W floats up from the process reference position under the pressure at the time of clamping the workpiece | work W, and the process precision of the workpiece | work W can be improved.
Further, when the clamping means 20 completely clamps the workpiece W, the contact surface between the workpiece W and the pad 43 has a linear shape extending in the vertical direction, and the contact surface between the workpiece W and the second contact means 50 is also vertical. It has a line shape extending in the direction.

Then, as shown in FIG. 9, the chucking operation is completed by turning the clamping means fixing bolt 32 on the lower surface of the table 30 to fix the clamping means 20.
Next, the operator removes the chuck device 10 from the rotation drive device 33, sets the chuck device 10 on the headstock of various processing devices such as cutting, and processes the workpiece W.
Most of the component of the force received by the clamping means 20 from the clamping means fixing bolt 32 is a downward force, and the downward force causes the clamping means 20 to be pressed against the upper surface of the table 30, so that the adjacent clamping It is possible to prevent an excessive stress or strain from being generated in the workpiece W between the means 20.

Here, a case where “an excessive stress or strain occurs in the workpiece W” will be described.
For example, as a result of a problem in clamping the workpiece W by the clamping means 20, an excessive external force component is generated in a direction other than the radial direction of the workpiece W among the external forces acting on the workpiece W from the clamping means 20. In this case, it is assumed that excessive stress is generated in the surface of the workpiece W, and as a result, excessive strain is generated in the workpiece W.
When excessive stress or distortion is generated in the workpiece W when the clamping means 20 is fixed to the table 30, even if the workpiece W is centered, chatter or the like caused by the stress or strain during processing is performed. This causes a problem that machining cannot be performed or machining accuracy is remarkably lowered.
In other words, in the chuck device 10 of the present embodiment, the clamping means 20 is fixed by pressing the clamping means 20 against the upper surface of the table 30 by a downward force using the clamping means fixing bolt 32 on the lower surface of the table 30. The structure is such that excessive stress and strain can be prevented from being generated in the workpiece W between the clamping means 20.
Even when the clamping means 20 accurately clamps the workpiece W and the clamping means 20 is accurately fixed to the table 30, the clamping means 20 naturally distorts the workpiece W with respect to the workpiece W. However, the stress or strain caused by the external force is not included in the “excessive stress or strain”.

As described above, the chuck device 10 according to the present embodiment fixes the workpiece W to the table 30 in a state where the plurality of clamping means 20 clamps a plurality of peripheral portions at the lower portion of the cylindrical workpiece W. Since various processes such as cutting can be performed with the stress and strain generated in W kept to a minimum, a thin-walled cylinder with a diameter of 200 mm, a length of 200 mm, and a thickness of about 2 mm made of carbon steel has been difficult in the past. Can be produced.
In particular, when the clamping means 20 is in linear contact with both the outer and inner surfaces of the workpiece W, the stress acting on the workpiece W when clamping the workpiece W and the distortion resulting therefrom can be minimized.

In the present embodiment, the bolt 42 of the first contact means 40 is inclined about 5 degrees downward with respect to a plane (horizontal plane H) perpendicular to the rotation axis L of the workpiece W. What is necessary is just to incline to the process reference position side of the workpiece | work W.
In addition, the first contact means 40 has a swivel mechanism including a bolt 42 and a pad 43. However, the present invention is not limited to this, and a member having elasticity such as silicon resin is fixed to the tip of the bolt 42. It may be in contact with the surface of the workpiece W.
In addition, the first contact means 40 is in contact with the outer surface of the workpiece W, and the second contact means 50 is in contact with the inner surface of the workpiece W. However, the second contact means 50 is in contact with the outer surface of the workpiece W, and the first contact means 40 is in contact with the outer surface of the workpiece W. The structure in which the contact means 40 contacts the inner surface of the workpiece W may be used.

Further, the clamping means 20 is fixed on the table 30 by the clamping means fixing bolt 32, but in addition, for example, by configuring both or one of the clamping means 20 and the table 30 with a magnetic member, The structure which fixes the clamping means 20 on the table 30 using magnetic force may be sufficient.
In addition, the first contact means 40 and the second contact means 50 of the clamping means 20 are joined to the connecting portion 60. However, the present invention is not limited to this, and the first contact means 40 and the second contact means 60 are not provided. A structure may be employed in which the contact means 50 is fixed to the table 30 separately using a well-known fastener.
Moreover, although the contact surface to the workpiece | work W by both the 1st contact means 40 and the 2nd contact means 50 was made into linear shape, at least any one contact surface should just be linear shape, for example, the workpiece | work W is a cross section. When the work W is clamped using a swivel mechanism including a bolt 42 and a pad 43, the contact surface formed by the second contact means 50 coming into contact with the inner surface of the work W is a linear shape. However, the contact surface due to the pad 43 coming into contact with the outer surface of the workpiece W is substantially circular.

Further, a structure in which the surface of the fixed portion 41 is brought into contact with the surface of the workpiece W without using the swivel mechanism including the bolt 42 and the pad 43 as the first contact means 40 may be used. In this case, the fixing part 41 may be structured to be movable in the front-rear direction using a worm gear like a so-called monkey wrench.
Further, the chuck device 10 of the present invention is used to clamp various workpieces W for cutting, grinding, polishing, etc. in various machine tools such as machining centers, lathes, milling machines, drilling machines, etc., and attach them to the machining head of the machine tool. It can be applied as a device.
If a plurality of clamping means 20 are arranged on the table 30 in a straight line, the plate-like member can be clamped and processed.
The chuck device 10 of the present invention is suitable for processing a thin cylindrical workpiece W, but may be thick and may have a polygonal cross section.

  This chuck device can process a thin workpiece by suppressing distortion and chatter during processing, and has industrial applicability.

H Horizontal plane L Rotating shaft W Workpiece 10 Chuck device 20 Clamping means 21 Workpiece clamping opening 30 Table 31 Positioning opening 32 Clamping means fixing bolt 33 Rotation driving device 40 First contact means 41 Fixing part 42 Bolt 43 Pad 44 Screw hole 50 Second contact means 51 Surface 60 Connecting portion 61 Screw hole 1

Claims (5)

Three or more clamping means for clamping the inner and outer surfaces of the hollow workpiece;
A table for fixing the clamping means,
The clamping means includes first contact means that contacts one of the inner and outer surfaces of the workpiece, and second contact means that contacts the other surface of the workpiece and facing the first contact means. ,
In the state where each clamping means clamps the workpiece, the acting direction of the pressure acting on the workpiece from the first contact means is inclined toward the processing reference position side of the workpiece with respect to the plane perpendicular to the rotation axis of the workpiece, In addition, the chucking apparatus is characterized in that each clamping means is fixed to the table so that excessive stress or strain is not generated between the adjacent clamping means.   In a state where each of the clamping means clamps a workpiece, at least one of the contact surface shape of the first contact means and the workpiece and the contact surface shape of the second contact means and the workpiece is linear. The chuck device according to claim 1, wherein the chuck device is provided.   The first contact means includes a fixed portion, a bolt that is pivotally supported by the fixed portion so as to be pivotable about an axis, and a pad that is supported by a tip of the bolt and contacts a workpiece. The chuck device according to claim 1, wherein the chuck device constitutes a swivel mechanism.   In a state where each of the clamping means clamps the workpiece, the acting direction of the pressure acting on the workpiece from the first contact means is inclined at an acute angle toward the machining reference position side of the workpiece with respect to a plane perpendicular to the rotation axis of the workpiece. The chuck device according to any one of claims 1 to 3, wherein the chuck device is provided. The chuck device according to claim 1, wherein the workpiece has a thin cylindrical shape.

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