JPH11309614A - Annular work holder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately work an annular work at low cost by forming a diameter enlarging member of a thin outer cylinder part capable of enlarging the diameter thereof in the radial direction, and enlarging the diameter of the outer cylinder part while pushing a piston provided in a holder and using the diameter enlarging means. SOLUTION: An annular work A to be worked is inserted outside of an outer cylinder 3 of a holder 1 till a left end thereof abuts on a side surface of a stepped part 4. Thereafter, when a piston 7 is pushed left by the center of a machine tool while resisting the elasticity of a spring 10, the oil 14 in a recessed part 9 is flowed to a space (oil reservoir) 12 through a groove 13. With this structure, the inner pressure of the oil 14 inside of the oil reservoir 12 rises, and the outer cylinder part 3 of the holder 1 is projected in the radial direction so as to evenly pressure-contact with the inner peripheral surface of the annular work A. As a result, centering of the annular work A is accurately performed, and strongly fixed to the holder 1 without deforming the outer peripheral surface thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an annular workpiece holder for holding an annular workpiece such as a mold part when the workpiece is machined by a machine tool.

[0002]

2. Description of the Related Art An outer peripheral portion of a holder is overhanged, and the overhanging outer peripheral portion is pressed against an inner peripheral surface of an annular workpiece to accurately center and hold the annular workpiece without being deformed. This type of workpiece holding device configured to be able to machine with high precision is proposed in Japanese Utility Model Laid-Open No. 6-609.

[0003]

SUMMARY OF THE INVENTION
The work holding device proposed in Japanese Unexamined Patent Publication No. -609 requires a large number of parts and is difficult to manufacture, and requires a drive device such as a draw bar or a hydraulic device as a means for extending the outer peripheral portion of the holding tool. Therefore, large-scale remodeling work is necessary to use it with existing machine tools, and if remodeling is performed, it will not be possible to use it exactly like a conventional machine tool There is a point.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and has a simple structure and is easy to manufacture. The purpose of the present invention is to provide a tool capable of holding a ring-shaped workpiece without any modification and without requiring a special driving device. A holding tool that abuts and holds by expanding the diameter, wherein the diameter-enlarging member is a thin-walled outer cylinder portion that can be expanded in the radial direction, and the outer diameter is increased by pushing a piston installed in the holding tool and expanding the diameter. An annular workpiece holder characterized in that a diameter of a cylindrical portion is increased.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to an embodiment shown in the drawings. In the drawings, reference numeral 1 denotes a holder for holding an annular workpiece A; It is a base unit that is attached to a machine by chucking or the like. Reference numeral 3 denotes a cylindrical outer cylinder portion extending from one end face 2A of the base portion 2 and formed of a thin portion.
A stepped portion 4 is formed on the one end surface 2A side of the outside of the connecting portion with the outer cylindrical portion 3.

Reference numeral 5 denotes an inwardly bent portion connected to the opening of the outer tube portion 3 and extends in the radial direction of the outer tube portion 3. A ring-shaped piston holding cylinder 6 extending in the direction of one end face 2A is connected. Reference numeral 7 denotes a piston which is inserted into the piston holding cylinder portion 6 and is provided so as to be water-tight and axially slidable via a seal ring 8 attached to the outer periphery on the right end 7A side thereof.
The other left end 7B extends to the vicinity of one end face 2A of the base 2.

Reference numeral 9 denotes a concave portion formed on one end surface 2A of the base portion 2. The left end portion 7B of the piston 7 is fitted into the concave portion 9, and the end surface of the left end portion 7B and the inner side of the concave portion 9 are provided. While the piston 7 is urged rightward by a spring 10 interposed between the piston and the wall, the retaining ring 11 installed in the opening of the piston holding cylinder 6 prevents the piston 7 from falling off. I'm preventing.

Reference numeral 12 denotes an oil reservoir space formed between the inner side of the outer cylinder 3 and the outer side of the piston 7.
The space 12 and the concave portion 9 are formed at almost the entire inner peripheral surface of the piston 7, and the space 12 and the concave portion 9 are formed at the distal end (the left end 7) of the piston 7.
B) They are communicated by a groove 13 formed on the outer periphery. Therefore, when the piston 7 is pushed leftward against the elasticity of the spring 10, the oil 14 in the recess 9 flows into the space 12 through the groove 13, and the oil 14 in the space 12 14, the internal pressure is increased. In the figure, reference numeral 15 denotes an oil supply / drain hole into the recess 9;
Usually, it is closed by a set screw plug 16.

Reference numeral 17 denotes a through hole formed at the center of the piston 7, and a stroke end pin 18 is provided in the through hole 17.
Is mounted on the left side thereof with a screw structure 19, and is mounted on the right end side so as to be water-tight and axially movable via a seal ring 20 mounted on the outer periphery thereof. This makes it possible to freely adjust the pushing amount of the piston 7.

Next, to explain the operation, the holder 1 is attached to a machine tool (not shown) by chucking at the base portion 2. Then, the annular workpiece A to be machined is inserted outside the outer cylindrical portion 3 of the holder 1 until the left end of the annular workpiece A contacts the side surface of the step portion 4. Then, the piston 7 is moved to the spring 1 by a machine tool center or the like.
0 to the left in the figure against the elasticity of
The oil 14 in the space (oil sump) 1 passes through the groove 13.
Flow into 2. Thereby, the oil 14 in the oil reservoir 12 is
, The outer cylindrical portion 3 of the holder 1 protrudes in the radial direction, and uniformly presses the inner peripheral surface of the annular workpiece A.

As a result, when the annular workpiece A is accurately centered, the outer peripheral surface thereof is firmly fixed to the holder 1 without being deformed. The workpiece A can be processed. If it is difficult to adjust the pushing amount of the piston 7 by the center when fixing the annular workpiece A to the holder 1, the stroke end pin 18 is tightened to tighten the stroke end pin 18 in the concave portion 9 of the distal end portion 18A. If the length of the protrusion is large, the amount of pushing of the piston 7 can be easily adjusted.

After the machining, if the center of the machine tool is retracted, the piston 7 is pushed back to the right by the restoring force of the spring 10, and the internal pressure of the oil 14 in the recess 9 is reduced. Part of the oil 14 in the reservoir 12 flows into the recess 9 through the groove 13. As a result, the internal pressure of the oil 14 in the oil reservoir 12 decreases, and the outer cylindrical portion 3 that has protruded in the radial direction contracts in the radial direction and returns to the current state. Can be extracted.

[0013]

As described above, the holder for an annular workpiece according to the present invention is a holder for abutting and holding the inner surface of an annular workpiece by expanding the diameter, and the expanding member expands in the radial direction. It is a thin-walled outer cylinder that can be radiated, and has a configuration in which the outer cylinder is expanded by pushing a piston installed in the holder and expanding the diameter, so that the structure is extremely simple and easy to manufacture. It can be manufactured at low cost. In addition, since the driving force can use the center of the machine tool and does not require a specific driving device, it can be mounted on various machine tools without any modification, and as the use range expands, There are various effects that an annular workpiece can be machined at low cost and with high precision.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an annular workpiece holder according to the present invention.

FIG. 2 is a sectional view taken along the line II-II in FIG.

[Explanation of symbols]

 Reference Signs List A annular workpiece 1 holder 2 base 4 outer cylinder 6 piston holding cylinder 7 piston 9 recess 10 spring 12 oil sump space 13 groove 14 oil 18 stroke end pin

Claims (3)

[Claims] 1. A holding tool which is held in contact with an inner surface of an annular workpiece by expanding the diameter, wherein the expanding member is a thin outer cylinder portion which can be expanded in a radial direction, and is installed in the holding tool. An annular workpiece holder characterized in that the outer cylindrical portion is expanded in diameter by pushing a piston and expanding the diameter. 2. The annular workpiece holder according to claim 1, wherein the amount of pushing of the piston is adjusted by a stroke end pin mounted on the piston by a screw structure. 3. The holder for an annular workpiece according to claim 1, wherein the diameter expanding means of the outer cylinder portion is hydraulic.