JPH0215337B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a workpiece clamping device, and is particularly capable of clamping a workpiece for internal diameter machining or inspection in a positioned state.

When machining the internal diameter of a workpiece, such as the shaft hole of a gear, it is difficult to clamp at the tooth surface due to the risk of damaging the tooth surface. Therefore, clamping is usually performed at the boss, and Positioning is performed using the shaft hole. If the positioning body is in the position of the shaft hole during inner diameter machining or inspection, inner diameter machining or inspection becomes impossible.

Therefore, the first object of the present invention is to position the workpiece using a hole such as a shaft, and after clamping the workpiece, move the positioning body back from the hole position so that it does not interfere with internal diameter machining. be.

By the way, after the positioning body has positioned the work, it is necessary to securely fix the work by the clamp body, but if the synchronization of the movements of the two is uncertain, smooth clamping operation will not be possible.
In addition, if a drive source is provided for each clamp body and positioning body, the synchronization control of them becomes complicated.
Operating time becomes longer.

Therefore, a second object of the present invention is to reliably drive the clamping body and the positioning body in a synchronous state using one driving source.

Hereinafter, the present invention will be specifically explained based on an embodiment shown in the drawings.

A cylinder 3 serving as a driving source is attached to a side-open frame 2 of the clamp device 1.
The cylinder rod 4 of this cylinder 3 is supported by a rack 5 that is slidably supported laterally with respect to the frame 2.
is fixed at one end. This rack 5 meshes with a pinion 6. This pinion 6 has one eccentric shaft 7 at an eccentric position, and is rotatably supported by a housing 10 attached to the frame 2 by a shaft 8 and a bearing 9.

Further, the frame 2 has a support cylinder 11 integrally formed therein, and holds a cylindrical clamp body 12 and a positioning rod 13 slidably in the vertical direction inside this clamp body 12. ing. This clamp body 12 has an abutment surface 14 on the lower surface, and has three parts in the upper part for equalizing the clamping force.
While interposing two elastic bodies 15 at three equal positions,
The pressing body 16 is supported so as to be able to swing slightly. This pressing body 16 is annular and abuts along the outer periphery of a boss 18 of a workpiece 17 for inner diameter machining, and causes the upper surface of this workpiece 17 to abut against three workpiece receivers 19 . The workpiece receivers 19 are provided at three positions on the plate 21 and are rotatably supported by a support shaft 20. The plate 21 is attached to the upper surface of the frame 2, has a tool insertion hole 22 approximately at the center, and rotatably supports the support shaft 20 at the apex of a triangle on its outer periphery. Each of the support shafts 20 has a groove wheel 23 fixed at its upper end, and these groove wheels 23 are in a relationship of rotation in an interlocked state by an annular wire 24 wound around them. In addition, the positioning rod 13
is supported slidably in the vertical direction inside the clamp body 12, holds a conical positioning body 25 in its upper part, and has a horizontal part that fits into the eccentric shaft 7 on one lower side. A groove 26 is formed.

Further, the contact surface 14 is in contact with a square groove-shaped slope 28 of the sliding body 27. The sliding body 27 is supported within the frame 2 so as to be slidable laterally in the same way as the rack 5, and is connected to the rack 5 by a connecting shaft 29 with a compression spring 30 interposed therebetween. The compression spring 30 has a sliding body 27
The connecting shaft 29 is housed in a hole 31, and is inserted between the bottom of the hole 31 and a stopper 32 formed at one end of the connecting shaft 29. Note that this stopper 32 is
When the compression spring 30 is sufficiently compressed, it comes into contact with the end surface of the sliding body 27. Further, the connecting shaft 29 supports dogs 35, 36, and 37 by means of a bracket 33 and a horizontal screw shaft 34 in a state in which the positions thereof can be adjusted by means of screws. These dogs 35, 36, and 37 correspond to a limit switch 38 for clamp detection, a limit switch 39 for overclamp detection, and a limit switch 40 for unclamp detection, respectively.

Note that an air introduction port 42 is formed in the plate 21. This air inlet 42 is connected to a pressure air source 41 and reaches a nozzle 43 on the lower surface of the workpiece receiver 19 through the support shaft 20. This nozzle 43 is used to detect the close contact of the workpiece 17 to the workpiece receiver 19 and to perform cleaning by changing the air jetting state.

Next, the operation will be explained. The workpiece 17 is carried from the side of the frame 2 by a worker or a robot hand, and is clamped between the pressing body 16 and the workpiece receiver 19 inside the frame 2. FIG. 3 shows a state in which the workpiece 17 is clamped. In this clamped state,
Since the positioning rod 13 is lowered, the tool 44 for inner diameter machining descends from the tool insertion hole 22.
The hole 17a of the workpiece 17 can be machined without interfering with the positioning body 25.

Now, the operations up to the point where this clamping is performed will be described step by step. Initially, the cylinder rod 4 is moving forward as shown in FIG. 4, so that the rack 5 and the slide 27 are in the retracted position, ie, moving to the right in the figure. For this reason, the eccentric shaft 7 is at the unclamping position A, lowering the positioning rod 13 from the maximum raised position. Moreover, since the sliding body 27 is in contact with the contact surface 14 of the clamp body 12 at the lowest position of the slope 28, the clamp body 12 is at the maximum lowered position.
Therefore, a space necessary for inserting the workpiece 17 is formed between the pressing body 16 and the workpiece receiver 19.

When the workpiece 17 is supplied to the space above the positioning rod 13, the cylinder rod 4 is moved backward according to an appropriate command, and the rack 5 and the connecting shaft 29 are moved to the left. At this time, the stopper 32 presses the compression spring 30, so that the compression spring 30 elastically urges the sliding body 27 to the left. The slope 28 then slides on the abutment surface 14 and pushes the clamp body 12 upward. Therefore, the pressing body 16 of the clamp body 12 is in contact with the workpiece 17,
The workpiece 17 is lightly held between the workpiece receiver 19 and the workpiece 17 in a position adjustable state by the elasticity of the compression spring 30. When the rack 5 further moves to the left, the pinion 6 rotates clockwise, and when the eccentric shaft 7 is at position B, the positioning rod 13
As shown in Fig. 5, when the eccentric shaft 7 reaches the maximum raised position and reaches the position C, the positioning rod 1
3 moves to the maximum lowered position as shown in FIG. At this time, the rotation angle θ of the eccentric shaft 7 is approximately 180 degrees. In the process of the positioning rod 13 moving to the maximum raised position, the positioning body 25 first brings its conical guide surface into contact with the opening circumferential surface of the hole 17a of the workpiece 17, and then accurately positions the workpiece 17 with its cylindrical portion. As already mentioned, since the workpiece 17 is supported in a movable state, that is, in an elastically tightened state, by the elasticity of the compression spring 30, the conical guide surface of the positioning body 25 supports the workpiece 17.
Move horizontally to perform accurate positioning. After completing this positioning, positioning rod 1
3 escapes below the workpiece 17 by the rotation of the eccentric shaft 7, as shown in FIG. Further, in the process of moving the connecting shaft 29 to the left, the stopper 32 compresses the compression spring 30 and comes into contact with the rear end surface of the sliding body 27, so that the slope 28 exerts a wedge action on the contact surface 14. Initially, a large upward clamping force is applied to the clamping body 12, and the workpiece 17 is rigidly clamped between the pressing body 16 and the workpiece receiver 19 with a strong force. During this fixing, the elastic body 15 absorbs the inclination of the surface of the workpiece 17 due to incomplete machining by its elastic deformation, and clamps the workpiece 17 with an even pressing force. In this clamped state, the tool 44 for inner diameter machining is inserted into the hole 17a of the workpiece 17 from the inside of the tool insertion hole 22, and finishing and inspection of the inner diameter are performed. Thereafter, the cylinder rod 4 moves forward and the opposite operation to that described above is performed, and the sliding body 27 lowers the clamping body 12 with its slope 28. In this way, work 1
7 is in an unclamped state as shown in FIG. 4, and is taken out by a worker or an industrial robot.

In the above embodiment, the driving source is the cylinder 3, but this driving source is not limited to the cylinder 3.
Of course, other linear drive means may also be used.

In the present invention, since there is one driving source for the clamp body and the positioning rod, the movements of the two are reliably synchronized with a time difference, so positioning and clamping are reliable. Since the rod escapes from the position of the hole in the workpiece, the positioning rod does not interfere with internal diameter machining or measurement, allowing the necessary work to be carried out efficiently. Therefore, the clamping device of the present invention is extremely effective when it is necessary to position and clamp a gear at the position of an inner diameter hole, for example, like a gear.

[Brief explanation of drawings]

Fig. 1 is a plan view of the clamp device of the present invention, Fig.
The figure is a partially cutaway side view taken along the - line in Figure 3.
The figure is a vertical cross-sectional view of the device in the clamped state.
The figure is a vertical cross-sectional view of the same device in the unclamped state.
FIG. 5 is a vertical sectional view of the device in a positioned state. 1... Clamp device, 2... Frame, 3...
Cylinder as a driving source, 5...Rack, 6...
Pinion, 7... Eccentric shaft, 12... Clamp body,
13... Positioning rod, 14... Contact surface, 17
...Work, 17a... Hole, 19... Work receiver, 27... Sliding body, 28... Slope, 30... Compression spring.

Claims (1)

[Claims] 1. A drive source, a rack driven by the drive source, a pinion that engages with the rack and has an eccentric shaft, and is slidably supported in a state in which it can reciprocate in conjunction with the eccentric shaft. A positioning rod, a clamp body slidably supported by the positioning rod, a workpiece holder that holds a workpiece facing the clamp body, and abutment of the clamp body on a slope driven by the drive source. A clamping device comprising: a sliding body that comes into contact with a surface.