JPH0424161B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a workpiece holding device used for mounting a workpiece on the main shaft of a machine tool.

[Conventional technology]

Conventionally, so-called interlocking chucks and the like have been known as this type of work holding device.

However, with this chuck of this conventional structure, the holding portion of the chuck that attempts to hold a long work is small and only one end is held, so there is a limit to machining accuracy due to a decrease in holding accuracy.

Therefore, the structure shown in FIG. 6 has been proposed.

This proposed structure includes a holding body 52 that can be attached to a main shaft 51 of a machine tool, pressing bodies 53 and 54 that are movable in the radial direction at the front and rear of the holding body 52 in the axial direction, and each pressing body. 53, 54 in the radial direction by a wedge action, and a drawbar 57 provided in the main shaft 51 so as to be movable by pushing and pulling. 57 are connected, and the other movable body 55 is slidably provided on the drawbar 57 and is pressed by a pressure spring 58.

Therefore, the holding body 52 holds a long cylindrical workpiece W.
the drawbar 5 through the cylinder mechanism (not shown).
7 to the right in the figure, the movable body 56 pushes the front pressing body 54 radially outward by a wedge action, and the movable body 55 is pressed on the drawbar 57 by the pressure spring 58. The movable body 55 slides to the right in the figure, pushes up the rear pressing body 53 radially outward by a wedge action, and presses the pressing body 53 on the inner circumferential surface of the workpiece W.
3 and 54 are pressed together to hold the workpiece W on the holding body 52.

In this case, one of the pressing bodies 54 is pushed up by the pressing force of the drawbar 57, and the other pressing body 53 is pushed up by the spring force of the pressing spring 58. Assuming that the pressing force of the drawbar 57 is configured to push up by the wedge action of a common moving body, the workpiece W
Because the inner diameter of the inner peripheral surface is uneven, the pressing bodies 53, 54
When the pressing body 53 and the workpiece W have different diameters,
This is because either the pressure contact with the inner surface of the workpiece W or the pressure contact between the pressing body 54 and the inner surface of the workpiece W may be insufficient.

[Problem to be solved by the invention]

However, in the case of the above proposed structure, one of the pressing bodies is structured to obtain the workpiece pressing force by the spring pressure of the pressing spring, so the workpiece pressing force is uniformly determined unless the spring is changed, and it is compatible with changes in the wall thickness and size of the workpiece. In other words, holding the workpiece becomes unstable due to insufficient pressure welding force, or deforming the workpiece due to excessive pressure welding force, making it impossible to hold the workpiece in an appropriate state, and increasing the spring pressure of the pressure welding spring. This has the disadvantage that the larger the drawing force of the drawbar is required.

[Means to solve the problem]

The present invention aims to solve these disadvantages, and the gist thereof is to provide a holding body that can be attached to the main shaft of a machine tool, and a holding body that is provided movably in the radial direction at the front and rear of the holding body in the axial direction. a pressing body, a movable body movable in the axial direction that moves each of the pressing bodies in the radial direction by a wedge action, and a drawbar provided in the main shaft so as to be able to push and pull,
The work holding device is characterized in that the drawbar is rotatably provided with a pinion, and the movable body is disposed on the pinion so as to be able to mesh with each other while facing each other.

[Effect]

Both moving bodies meshing with the pinion are pushed by the push action of the drawbar, and when one of the moving bodies presses the workpiece with a wedge action, one of the moving bodies stops, and the other moving body Pushed by the rotational movement of the pinion, the other pressing body presses against the workpiece by a wedge action.

〔Example〕

1 to 5 support embodiments of the present invention,
1 to 3 show a first embodiment, and FIGS. 4 and 5 show a second embodiment.

In the first embodiment shown in FIGS. 1 to 3, reference numeral 1 denotes a cylindrical holding body, which is coaxially attached to a main shaft 2 of a machine tool with a mounting bolt 3.

Reference numerals 4 and 5 denote pressing bodies, and six pressing bodies 4 and 5 are provided on the front and rear sides of the holding body 1, respectively, at equal radius of 6 so as to be movable in the radial direction. A spring 6 for preventing detachment of the pressing bodies 4, 5 is hung, and the outer peripheral surfaces of the pressing bodies 4, 5 are formed into a pressing surface 7, and wedge surfaces 8, 9 are formed on the inner surfaces of the pressing bodies 4, 5. .

10 and 11 are moving bodies, one of which is the moving body 1.
0 is provided in the holding body 1 so as to be movable in the axial direction,
A tapered wedge portion 12 is formed in the front portion to be pressed against the wedge surface 8 of one of the pressing bodies 4, and the other movable body 11 is provided within the one movable body 10 so as to be movable in the axial direction.
The wedge surface 9 of the pressing body 5 is attached to the front part of the other movable body 11.
A tapered wedge portion 13 is formed to be pressed against the movable body 1.
The front end 14 of 0 is prevented from rotating by a key 15.

Reference numeral 16 denotes a drawbar, which is provided within the main shaft 2 so as to be able to be pushed or pulled by a cylinder mechanism (not shown).

A pinion 17 is rotatably attached to the front end of the drawbar 16 by a shaft 19 via a bearing 18.
The rack portions 20 and 21 at the rear of 0 and 11 are arranged in mesh with each other so as to face each other.

Since this first embodiment has the above-mentioned configuration, when the drawbar 16 is pushed to the right in the figure by a cylinder mechanism (not shown), the movable body 1 meshes with the pinion 17.
0 and 11 are both pushed, and both pressing bodies 4 and 5 have a wedge surface 8 and a tapered wedge portion 12, and a wedge surface 9 and a tapered wedge portion 13.
is pushed outward in the radial direction by the wedge action of 17 moves in the axial direction while rotating, only the other moving body 11 is pushed, the other pressing body 5 presses against the inner peripheral surface of the workpiece W, and the workpiece W is held under pressure by both pressing bodies 4 and 5. Ru.

Also, when the drawbar 16 is pulled, both moving bodies 10,
11 retreats to the left in the figure, the wedge action between the wedge surfaces 8 and 9 and the tapered wedge parts 12 and 13 is released, and the workpiece W is released.

Therefore, even if the inner diameter accuracy of the press-contact surface of the workpiece W is uneven, both pressing bodies 4 and 5 can be pressed against the workpiece W by the pushing force of the drawbar 16, improving holding stability, and is suitable for precision machining. becomes.

The second embodiment shown in FIGS. 4 and 5 has a structure that presses and holds the cylindrical workpiece W from the outside, whereas the first embodiment presses and holds the workpiece W from the inside. It is something.

In addition, the same reference numerals are given to the same parts as those of the first embodiment in the description.

Reference numeral 1 denotes a holding body having a small cylindrical member formed within a cylindrical member, and is mounted coaxially to the main shaft 2 of the machine tool with a mounting bolt 3.

Reference numerals 4 and 5 denote pressing bodies, and six pressing bodies 4 and 5 are provided at the front and rear of the small cylindrical member of the holding body 1, respectively, at an equal radius of 6 so as to be movable in the radial direction. A return spring 22 for the pressing bodies 4, 5 is interposed between the pressing bodies 4, 5 and the holding body 1, and the inner circumferential surfaces of the pressing bodies 4, 5 are formed into a pressing surface 7, and the outer surfaces of the pressing bodies 4, 5 are provided with a wedge surface. 8 and 9 are formed.

10 and 11 are moving bodies, one of which is the moving body 1.
0 is provided in the holding body 1 so as to be movable in the axial direction,
A tapered wedge portion 12 is formed in the front portion to be pressed against the wedge surface 8 of one of the pressing bodies 4, and the other movable body 11 is provided within the one movable body 10 so as to be movable in the axial direction.
The wedge surface 9 of the pressing body 5 is attached to the front part of the other movable body 11.
A tapered wedge portion 13 is formed to be pressed against the movable body 1.
The front end 14 of 0 is prevented from rotating by a key 15.

Reference numeral 16 denotes a drawbar, which is provided within the main shaft 2 so as to be able to be pushed or pulled by a cylinder mechanism (not shown).

A pinion 17 is rotatably attached to the front end of the drawbar 16 by a shaft 19 via a bearing 18.
The rack portions 20 and 21 at the rear of 0 and 11 are arranged in mesh with each other so as to face each other.

Since this second embodiment has the above-mentioned configuration, when the drawbar 16 is pushed to the right in the figure by a cylinder mechanism (not shown), the movable body 1 meshes with the pinion 17.
0 and 11 are both pushed, and both pressing bodies 4 and 5 have a wedge surface 8 and a tapered wedge portion 12, and a wedge surface 9 and a tapered wedge portion 13.
At this time, for example, if one of the pressing bodies 4 comes into pressure contact with the outer circumferential surface of the work W first, one of the pressing bodies 10 stops, and the pushing action of the drawbar 16 pushes the pinion 17 moves in the axial direction while rotating, only the other moving body 11 is pushed, the other pressing body 5 presses against the outer peripheral surface of the workpiece W, and the workpiece W is held in pressure contact with both the pressing bodies 4 and 5.

Also, when the drawbar 16 is pulled, both moving bodies 10,
11 retreats to the left in the figure, the wedge action between the wedge surfaces 8 and 9 and the tapered wedge parts 12 and 13 is released, and the workpiece W is released.

Therefore, even if the precision of the pressed surface of the workpiece W is uneven, both the pressing bodies 4 and 5 can be pressed against the workpiece W by the pressing force of the drawbar 16, and the holding stability can be improved, making it suitable for precision machining. Become.

〔Effect of the invention〕

As described above, the present invention allows both pressing bodies to be pressed against the workpiece W by the pushing force of the drawbar even if the accuracy of the pressed surface of the workpiece is uneven, improving the stability of holding, and making it suitable for precision machining. Become.

As described above, the intended purpose can be fully achieved.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention; FIG. 1 is a cross-sectional view of the first embodiment, FIG. 2 is a cross-sectional view thereof,
3 is a cross-sectional view thereof, FIG. 4 is a cross-sectional view of the second embodiment, FIG. 5 is a cross-sectional view thereof, and FIG. 6 is a cross-sectional view of the conventional structure. 1... Holding body, 2... Main shaft, 4, 5... Pressing body, 10, 11... Moving body, 16... Drawbar,
17...Pinion.

Claims (1)

[Claims] 1. A holding body that can be attached to the main shaft of a machine tool, a pressing body that is movable in the radial direction at the front and rear of the holding body in the axial direction, and each pressing body is moved in the radial direction by a wedge action. A movable body that is movable in the axial direction, and a drawbar provided within the main shaft so as to be able to push and pull, a pinion rotatably provided on the drawbar, and the movable body can be engaged with the pinion in a mutually opposing state. A work holding device characterized in that it is arranged and configured.