JPS632273Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a parallel chuck whose width can be freely adjusted according to the size of the workpiece.

Conventional chucks of this type are opened and closed by moving a pair of chuck holders in parallel using a reverse screw mechanism or a parallel link mechanism.
However, if the chuck holder is of a type that opens and closes only by a screw mechanism, there is a limit to the rotational speed of the reverse screw, so the opening and closing operations cannot be performed quickly. On the other hand, in the case of a type in which a pair of chuck holders are opened and closed by a parallel link mechanism, the opening and closing operations are performed quickly, but the opening and closing range is limited by the length and rotation angle of the parallel links, and the opening and closing range is limited by the length and rotation angle of the parallel links. become unable.

Therefore, the purpose of the present invention is to make use of the features of the screw mechanism and the link mechanism and compensate for the drawbacks of both, so that the chuck width can be adjusted over a wide range, and the chuck can be opened and closed quickly. The objective is to provide such a mechanism.

Based on the above object, the present invention uses a parallel link mechanism to perform opening/closing movements for gripping and releasing a pair of chuck holders, and allows the interval between the chuck holders to be adjusted by a reverse screw mechanism.

However, if the parallel link mechanism and screw mechanism are simply combined, when the reverse screw mechanism changes the distance between the parallel links, that is, the distance between the pair of chuck holders, the parallel link mechanism rotates, so the pair of chuck holders changes. The posture of the holder changes. Therefore, the opening/closing range of the chuck holder tends to be unclear.

Therefore, another object of the present invention is to enable the distance between a pair of chuck holders to be freely adjusted using a screw mechanism without changing their positions.

For the above purpose, the present invention engages one arm of each of the pair of parallel link mechanisms with an elongated hole in the same direction as the feed screw axis of the reverse screw, and the member of the elongated hole, that is, the long The hole plate is driven by a cylinder to open and close the chuck holder, and when the interval between the chuck holders is adjusted by rotating the screw shaft, one end of the arm is moved along the elongated hole while maintaining the same posture. ing.

Hereinafter, the configuration of the present invention will be specifically explained based on the embodiments shown in the drawings.

The size-variable parallel chuck 1 of the present invention includes a cylinder 2 for opening and closing the chuck, and a forward/reverse motor 3.
is attached to a base frame 4, and a screw shaft 5, a pair of movable bodies 6, a pair of chuck holders 7, a pair of levers 8, and an arm 9 are assembled to the base frame 4.

The cylinder 2 is mounted perpendicularly to the center of the base frame 4, and the piston rod 11 of the internal piston 10 connects the elongated hole plate 12 to the screw shaft 5.
It is supported in a direction parallel to. The cylinder 2 takes in pressurized air 14 from the air intake port 13 to move the piston 10 in the direction of arrow A, but the return of the piston 10, that is, arrow B
The movement is carried out by a spring 15 built into the interior. And the long hole plate 12
A long hole 16 parallel to the axial direction of the screw shaft 5 is formed at both end portions thereof over the movement range of the movable body 6.

The forward/reverse motor 3 is attached to either one of the base frames 4, and timing pulleys 17 and 18 are attached to one end of the motor shaft and screw shaft 5, and a timing belt 19 is wound around them. This gives rotation to the screw shaft 5 in the forward or reverse direction. The screw shaft 5 is rotatably supported by a ball bearing 21 on a pair of brackets 20 attached to both ends of the base frame 4. Further, the pair of brackets 20 fixedly support the guide bar 22 in a state parallel to the screw shaft 5. A proximity switch 28 for detecting the origin is attached to one of the brackets 20.

The pair of movable bodies 6 are engaged with the screw 5a of the screw shaft 5 at the female thread 6a, and are slidably fitted into the guide bar 22 at the guide hole 6b. Screw 5a and female thread 6a
are symmetrical with respect to the center position, that is, have a reverse thread relationship. The movable bodies 6 each rotatably support a doglegged arm 9 by a support shaft 23. A slider pin 24 at one end of this arm 9 is slidably fitted into the elongated hole 16, and a pin 25 at the other end
are rotatably connected to a pair of chuck holders 7, respectively. Further, the chuck holder 7 and the movable body 6 are connected by pins 26 and 27 at both ends of the lever 8. The support shaft 23 and the pins 25, 26, 27 are on two sets of parallel lines. Therefore, the movable body 6, chuck holder 7, lever 8 and arm 9 form a four-bar parallel link. A chuck pawl 29 corresponding to each workpiece is attached to the chuck holder 7.

Next, the operation of the variable size parallel chuck 1 will be explained.

Normally, the spring 15 pushes the piston rod 11 in the direction of arrow B, so the left and right arms 9
The pair of chuck holders 7 are moved in a direction away from each other, and the pair of chuck claws 29 are opened. When pressurized air 14 is fed into the air intake port 13 in this state, the piston 11 moves the piston rod 11 in the direction of arrow A. At this time, in FIG. 1, the left arm 9 rotates counterclockwise and the right arm 9 rotates clockwise, so the pair of chuck holders 7 move toward each other. It becomes closed. The movement locus of the chuck holder 7 at this time is a parallel movement due to the nature of the parallel link mechanism. In this way, the pair of chuck holders 7 are opened and closed by the cylinder 2, and a desired workpiece is gripped or released by the left and right chuck claws 29.

By the way, when the size of the workpiece changes, the distance between the pair of chuck holders 7 is determined by the forward/reverse motor 3.
can be adjusted by rotating in either direction. That is, since the rotation of the forward/reverse motor 3 is transmitted to the screw shaft 5, the screw shaft 5 moves the pair of movable bodies 6 in different directions by rotating the screw 5a in the opposite direction. At this time, the guide bar 22 is
The movable body 6 is guided in a non-rotating state. Therefore, the distance between the movable bodies 6, that is, the pair of chuck holders 7 moves along the axial direction of the screw shaft 5, and changes the distance. During this movement, each arm 9 will naturally also move, but both arms 9
Since the slider pins 24 move along the respective elongated holes 16 parallel to the screw shaft 5, the pair of chuck holders 7 can move along the screw shaft while maintaining the original state, for example, the open or closed position. 5 in the axial direction. Therefore, when changing the width of the pair of chuck holders 7, the pair of arms 9
maintains the same rotational position, the left and right chuck holders 7 continue to maintain their pre-adjustment positions.
Therefore, the opening/closing range of the pair of chuck holders 7 by the arms 9 can be easily confirmed.

If the pair of arms 9 rotate when the movable body 6 moves in the direction of the screw shaft 5, the maximum open position of the pair of chuck holders 7, for example, cannot be confirmed, so It is necessary to set the maximum open position. However, such complicated operations are unnecessary in the present invention because of the above functions. The maximum open position of the movable body 6 is
This can be detected by a limit switch 28 attached to the bracket 20.

Note that since the arm 9 converts the reciprocating linear motion of the elongated hole plate 12 into a rotational movement of the arm 9 about the support shaft 23, if it is not perpendicular to the elongated hole 16, its inclination will change. The direction may be opposite to that of the example. Further, the forward/reverse motor 3 is
It may be of a type that is directly connected to the screw shaft 5. Also, cylinder 2 for opening and closing the chuck.
is constructed as a single-acting cylinder, but it may of course be a multiple-acting cylinder. Furthermore, if the chuck holder 7 is formed into an inverted L shape as shown in FIG. 3, the chuck width can be increased.

The present invention has the following unique effects. In other words, since the pair of left and right arms are driven by one cylinder, there is no timing difference between the opening and closing movements of the left and right chuck holders, and it is easy to center the opening and closing movements, and the reproducibility is also improved. is ensured. Since the pair of movable bodies are not equipped with a drive source for opening and closing, they can be configured to be relatively lightweight, so the driving force of the forward/reverse motor is small, and the pair of movable bodies can be driven quickly.
No need for piping to chuck holders or movable bodies. In particular, when the movable body moves in the axial direction of the screw shaft, the slider pin of the arm moves along the direction of the elongated hole parallel to the screw shaft, and the arm does not make any rotational movement. When adjusting the distance between the chuck holders, it can be done with the pair of chuck holders open or closed, so the posture of the pair of chuck holders does not change, and the opening/closing range can be adjusted according to the distance. It can be easily confirmed later.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway plan view of a variable-size parallel chuck of the present invention, Fig. 2 is a partially sectional view taken along the - line in Fig. 1, and Fig. 3 is another embodiment of the chuck holder. FIG. 1... Parallel chuck with variable size, 2... Cylinder for opening and closing the chuck, 3... Forward/reverse motor,
4... Base frame, 5... Screw shaft, 6... Movable body, 7...
...chuck holder, 8 ... lever, 9 ... arm, 12 ... long hole plate, 16 ... long hole, 22 ... guide bar, 23 ... spindle, 24 ... slider.

Claims (1)

[Scope of utility model registration request] A cylinder for opening and closing the chuck and a forward/reverse motor for changing the size are fixed to a base frame, and a screw shaft with symmetrical threads is rotatably supported on this base frame. A movable body is rotatably connected to each screw, a chuck holder is supported on each movable body by parallel and rotatable levers and arms, and a long hole plate having a long hole parallel to the screw axis is provided. A parallel chuck of variable size, which is fixed to the piston of the cylinder, one arm of each movable body extending diagonally upward and slidably connected to the elongated hole.