JPH0243631Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a clamp device that positions and supports a workpiece on a jig body provided in a machine tool.

[Prior art]

In a clamp device that presses and supports a workpiece on a jig body at a plurality of clamp positions, it is necessary to maintain an equal pressing force at each clamp position in order to reliably support the workpiece without deforming it. For this purpose, in conventional clamping devices, a floating mechanism is provided at the tip of the clamp arm that presses the workpiece, and the workpiece is pressed against the jig body using a plurality of presser feet provided on this floating mechanism. ing.

[Problem that the invention attempts to solve]

However, in such conventional techniques, especially those with three or more clamping positions, the floating mechanism, which is the part that comes into contact with the workpiece, is large, so it interferes with the spindle cutting tool of the machine tool and allows free machining. There is also the problem that it is difficult to remove chips, which impedes machining.
Such problems are particularly serious when processing a bowl-shaped workpiece by clamping it inside. The present invention solves these problems by providing one clamp arm for each clamp position and providing a clamp cylinder that adjusts the pressing force separately from each clamp position, and also reduces the pressing force at each clamp position. This allows the clamp to be maintained at a predetermined value and can be clamped even in narrow spaces.

[Means for solving problems]

For this purpose, the workpiece clamping device according to the present invention includes an actuating cylinder device 20 having an actuating rod 21 fixed to a jig body 10, and a working cylinder device 20 having an actuating rod 21 fixed to the jig body 10, and a working cylinder device 20 having an actuating rod 21 fixed to the jig body 10, as illustrated in the embodiment of the accompanying drawings. A fixed support bracket 22 and a common pivot 23 provided on the support bracket 22 at right angles to the actuation rod 21 are pivotally supported independently of each other and substantially parallel to each other in both directions intersecting the actuation rod 21. three or more clamp arms 25 extending;
26, 27, and clamp rods 31 which are provided on the jig main body 10 in correspondence with the respective clamp arms and are movable by applying a biasing force in the axial direction.
By moving the actuating rod 21 in a predetermined direction, each of the clamp arms 25, 26, 27 has one end 25a, 26a, 27a in the same direction, and the same number of clamp cylinder devices 30 are provided. The other end portions 25b, 26b, and 27b abut against the workpiece placed on the workpiece placed above, and the respective other end portions 25b, 26b, and 27b abut against the tip of the clamp rod 31 of each of the clamp cylinder devices 30, and the one end portion 2 is moved by the biasing force.
5a, 26a, 27a hold the workpiece W in the jig main body 10.
It is characterized by applying a pressing force toward.

[Effect]

When the actuating rod 21 of the actuating cylinder device 20 moves in a predetermined direction, each clamp arm 25, 26, 27 pivotally supported by the support bracket 22 also moves, and one end portion 25a, 26a, 27a of each moves to the jig main body 10. It comes into contact with each clamp position of the workpiece W placed above. At the same time, the tip of the clamp rod 31 of each clamp cylinder device 30 is connected to the other end 25b, 2 of each clamp arm 25, 26, 27.
6b, 27b, and press these to give each clamp arm 25, 26, 27 a rotational moment about the pivot 23, and each one end 25a, 26
a, 27a apply a force to press the workpiece W toward the jig main body 10.

[Effect of idea]

As mentioned above, the present invention pivots a plurality of clamp arms by a common pivot, one end of each is brought into direct contact with the workpiece, and pressing force is applied by a clamp cylinder device provided at the other end of each clamp arm. As a result, each clamp arm has a smaller shape at one end that contacts the workpiece, and can be bent freely along the way, allowing free machining while avoiding interference with the spindle cutting tool of the machine tool, making cutting easier. Powder can also be easily removed. In addition, each clamp arm is independently pivoted and each is equipped with a clamp cylinder device, so the pressing force at each clamp position is always maintained at a predetermined value regardless of dimensional errors in the clamp device or the workpiece. can be kept.
Furthermore, since each clamp arm is moved by the actuating cylinder device and comes into contact with the workpiece and the clamp cylinder device, the rotation angle of the clamp arm for clamping and unclamping is reduced, and the clamp arm can be easily connected to other members even in narrow spaces. Workpieces can be tightened without causing interference.

〔Example〕

Examples will be described below with reference to the accompanying drawings.

As shown in FIGS. 1 and 2, an operating cylinder device 20 is provided vertically on one side of the jig main body 10 on which a bowl-shaped workpiece W is placed via seat blocks 11, 11. , actuating cylinder device 20
A support bracket 22 is fastened to the tip of the actuating rod 21 which projects upwardly with a nut. Three clamp arms 25, 26, and 27 are supported on the support bracket 22 by a single pivot shaft 23 provided at right angles to the actuating rod 21 so as to be rotatable within a certain range of angles independently of each other. ing.

Each clamp arm 25, 26, 27 extends substantially parallel to each other in both directions intersecting the actuating rod 21 while being bent, and each one end 25 on the workpiece W side
As shown in FIG. 2, a, 26a, and 27a are arranged so as to be located at clamp positions spaced apart from each other in a triangular shape within the workpiece W. Each end 2
5a, 26a, 27a are each clamp arm 25,
26 and 27, and as shown in FIG. 1, when the actuating rod 21 is lowered, it comes into contact with the inner surface of the workpiece W placed on the jig body 10. There is. The other ends 25b, 26b, 27b on the side opposite to the workpiece W are bent downward, and when the actuating rod 21 is lowered as described above, the tip thereof is connected to the clamp cylinder device 3, which will be described later.
0, 30, 30 clamp rods 31, 31, 3
It is brought into contact with the tip of 1. On the one end portions 25a and 27a of the clamp arms 25 and 27, there are reliefs 25c which are bent as shown in FIG. 2 and are used to interfere with the spindle cutter for machining the machining holes Wa and Wa.
and 27c are provided.

In this embodiment, the clamp cylinder body 13 fixed to the jig body 10 via the actuating cylinder device 20 has respective clamp arms 25, 26,
27, three identical clamp cylinder devices 30 are provided. Each clamp cylinder device 30 includes a cylinder 3 formed vertically in the clamp cylinder body 13, as shown in FIG.
2. Piston 31 inserted into this cylinder 32
It is composed of a clamp rod 31 having a lower end a, a spring 33 that urges the clamp rod 31 upward, and a lid member 34 that slidably supports the clamp rod 31, and the tip of the clamp rod 31 projects upward from the lid member 34. . A fluid whose pressure has been reduced to a predetermined pressure by a pressure reducing valve 35 is introduced into each cylinder 32 via a communication passage 36, and a spring 33 applies a biasing force to the clamp rod 3.
1 upwardly. In this embodiment, from the pivot 23 to the one end portions 25a, 26
The horizontal distance between the pivot shaft 23 and each clamp cylinder device 30 is set to be changed according to the difference in the distance to a, 27a, and the upward biasing force of each clamp rod 31 causes one end 25a of each clamp arm 25, 26, 27. , 26a, 27a press the workpiece W with almost equal force.

When the actuating rod 21 of the actuating cylinder device 20 is moved upward, each clamp arm 25, 2
6, 27 are both ends 25a, 26a, 27a
and 25b, 26b, and 27b are the workpieces W, respectively.
and the support bracket 22 via the pivot shaft 23.
The clamp cylinder device 30 is rotatably supported within a certain range of angles, and no fluid pressure is applied to the cylinder 32 of each clamp cylinder device 30. In this state, the processed workpiece W is removed, and the unprocessed workpiece W is placed on the jig main body 10.

Next, the actuating rod 2 of the actuating cylinder device 20
1 downward, each clamp arm 25,
Both ends 25a, 26a, 27a and 25b, 26b, 27b of 26, 27 abut against the inner surface of the workpiece W and the tip of the clamp rod 31, respectively. When the actuating rod 21 is further moved downward, the workpiece W is pressed lightly by the pressure of each spring 33.
In this state, the notch pin 12 is raised by a cylinder device (not shown), and the two notched holes in the workpiece W are opened.
The dowel pin 12 is inserted into the jig body 10, and is positioned and pressed onto the seat block 11 of the jig body 10, resulting in the state shown in FIG. In this state, fluid pressure is supplied to each clamp cylinder device 30 via the pressure reducing valve 35 and the communication path 36 to further press the workpiece W onto the jig main body 10 and complete clamping. In this state, the machining holes Wa, Wa are machined, and after machining, the workpiece is replaced with an unmachined one in the same manner as described above.

In the above embodiment, each clamp cylinder device 30 is the same, and the horizontal distance from the pivot 23 is changed so that the pressing force at each clamp position is approximately equal, but the cylinder 32 of the clamp cylinder device 30 and It is also possible to use pistons 31a with different diameters so that the respective pressing forces are approximately equal.

[Brief explanation of the drawing]

The drawings show an embodiment of the workpiece clamping device according to the present invention, with FIG. 1 being an overall side view with main parts cut away except for each clamp arm, and FIG. 2 being an overall plan view. Explanation of symbols, 10... Jig body, 20... Actuation cylinder device, 21... Actuation rod, 22... Support bracket, 23... Pivot, 25, 26, 27
...Clamp arm, 25a, 26a, 27a...
...One end, 25b, 26b, 27b...other end,
30... Clamp cylinder device, 31... Clamp rod, W... Workpiece.

Claims (1)

[Scope of utility model registration request] an actuating cylinder device fixed to the jig body and having an actuating rod; a support bracket fixed to the tip of the actuating rod; and a common pivot provided on the support bracket at right angles to the actuating rod, independently of each other. three or more clamp arms that are pivotally supported and extend substantially parallel to each other in both directions intersecting the actuating rod, and are provided on the jig body corresponding to each of the clamp arms and are each provided with a biasing force in the axial direction. The same number of clamp cylinder devices having movable clamp rods are provided, and by movement of the actuating rod in a predetermined direction, each of the clamp arms has one end in the same direction attached to a workpiece placed on the jig body. At the same time, each of the other ends abuts against the tip of the clamp rod of each of the clamp cylinder devices, and each of the one ends applies a force to press the workpiece toward the jig body due to the biasing force. Workpiece clamping device.