JP2008264981A - Toggle type hand - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a toggle type hand stably gripping a workpiece at a dead center of a toggle mechanism even when there is some variation in workpiece dimensions and without being damaged even in clamping the unexpected workpiece. <P>SOLUTION: This toggle type hand to grip an operation plate provided on a piston head end of a fluid pressure cylinder and master jaws connected to a body free to rotate at a position where a connecting part with the master jaws of respective levers is separated most by connecting them on both ends of the lever free to rotate, is provided with working shafts constituting a rotating connecting part of the operation plate and the master jaws on the both ends of the lever, respectively provided with spring guides applying a load on the working shafts in a direction where they are separated from each other and provided with a spring between the spring guides. The spring guide guides the spring so that the spring does not move and is made in length within which the spring is not attached but the working shaft stops. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a toggle-type fluid pressure hand that clamps a workpiece by opening and closing a claw with a fluid pressure cylinder.

A transfer hand using a fluid pressure cylinder is widely known, and is attached to the tip of a robot to clamp a workpiece and used for transfer and assembly.

Among them, the toggle-type hand opens and closes the pawl by a turning motion, so that it is light in weight and has a gripping force, and is suitable for clamping a dedicated work.

The toggle mechanism of the toggle type hand connects the operating plate provided at the tip of the piston of the fluid pressure cylinder and the master jaw pivotally supported by the body of the hand so that it can rotate at both ends of the lever. Is converted into a horizontal force to generate a large force, and the maximum force is generated at the position where the connecting portion of each lever with the master jaw is farthest (dead point).

In addition, by clamping at the dead point, the force on the master jaw side does not generate a force in the direction of moving the piston, so the claw will not move even if an unexpected situation such as the supply of fluid pressure as the drive source stops. It is often used because it does not open and prevents the workpiece from falling.

However, if there is a variation in the workpiece dimensions, the workpiece will be clamped before it reaches the dead point. In that case, the workpiece is not prevented from falling, so there is a risk that the workpiece may fall. There's a problem.

As a method for preventing the above problem, a method disclosed in Japanese Utility Model Laid-Open No. 4-106190 has been proposed.

This device has multiple incisions in the middle of the left and right levers of the toggle type hand, and the lever is elastically stretchable to absorb the workpiece size variation, and the lever can be moved to the dead point to prevent falling. It is characterized by that.

However, since the above device is provided with a plurality of cuts in order to configure the lever as an elastic member, it is difficult to set dimensions such as the number, amount and accuracy of cuts to ensure the strength of the lever. Because it is greatly affected by surface treatment, precise settings and parts management are required.

In addition, if the workpiece is larger than the set workpiece variation, the amount of elasticity of the lever also increases, and if the load exceeds the lever elasticity limit, the lever may be destroyed.
Japanese Utility Model Publication No. 4-106190

  It is an object of the present invention to provide a toggle-type hand that can be stably gripped at the dead point of the toggle mechanism even when there is some variation in workpiece dimensions, and does not break even when an unexpected workpiece is clamped. Objective.

  In the present invention, as means for solving the above-described problems, an operation plate provided at a piston tip of a fluid pressure cylinder and a master jaw rotatably connected to the body are rotatably connected at both ends of the lever, In a toggle-type hand that is gripped at the position where the connecting part of the lever with the master jaw is the farthest away, an operating shaft that constitutes the rotating connecting part between the operation plate and the master jaw is provided at both ends of the lever, and the operating shaft is moved away from each other. Install a spring guide to apply the load, and install a spring between the spring guides.

In addition, the spring guide guides the spring so that it does not move, and makes the operating shaft stop at such a length that the spring does not adhere.

Further, the spring is configured by using a combination of a plurality of springs so that the directions of the springs in contact with each other are opposite to each other.

The distance between the axes of the lever of the toggle type hand changes according to the workpiece dimensions by adopting the above configuration, so the operation plate can move to the dead center position when the workpiece is gripped, and the fluid pressure is cut off. The work is never dropped even in unexpected situations.

In addition, the spring guide is provided to prevent the spring from dropping or deforming, and even if it is gripped with a non-standard size due to a different product or a clamping error, the spring will be damaged by pressing the spring. Can be prevented.

Furthermore, since the springs can be made with a heavy load by constituting the springs in a staggered combination, a space-saving and powerful spring can be constructed.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

As shown in FIG. 1, the toggle type hand of this embodiment is rotated by a cylinder 1 and a piston 2 constituting a fluid pressure cylinder, an operation plate 7 fixed to the tip of the piston 2, an operation plate 7 and an operation shaft 3. The lever 4 that can be connected, and the other side of the lever 4 are rotatably connected by the master jaw 6 and the operating shaft 3, and the master jaw 6 is rotatably connected to the body 12 by the fulcrum shaft 5.

In general, as shown in FIG. 6, the lever 4 has circular holes in which the operating shaft can rotate at both ends of the plate, and the distance between the holes is kept constant. In the example, as shown in FIGS. 3 and 4, the hole into which the operating shaft 3 enters both ends is configured with the lever 4, the spring guide A 9 and the spring guide B 10, and the operating shaft 3, the spring guide A 9 and the spring guide B 10 are A hole is constructed that can slide inside.

A hole for guiding the spring is formed in one or both of the spring guide A9 and the spring guide B10, and the spring 8 is inserted between the spring guide A9 and the spring guide B10. B10 is expanded and the operating shaft 3 is also expanded to the lever 4.

In general, when the workpiece is gripped as shown in FIG. 7, the position where the lever 4 and the operating shaft 3 are farthest from each other is a dead point. Therefore, when the claw 14 fixed to the master jaw 6 grips the workpiece 15. A nail is formed or adjusted so as to be at the position of the dead point, and is gripped.

However, if the dimensional variation of the work 15 is large, it cannot be gripped at the dead point. Therefore, in this embodiment, the distance between the operating shafts inserted into the lever 4 can be reliably changed as shown in FIG. The operation plate 7 can be moved to the dead point and can be gripped even with workpieces having large variations, and a mechanism for preventing the fall can be maintained.

As shown in FIG. 5, the spring 8 is used by alternately combining the directions of the spring springs 13, and the hole of the spring guide A9 and the shaft 11 are incorporated as a guide for preventing the spring springs from dropping, but the spring 8 does not fall off. Any other guide method may be used as long as the spring 8 is a compression coil spring or a torsion coil spring.

Next, the operation will be described. FIG. 1 shows a state in which the master jaw 6 is open. When the fluid pressure enters from the lower port, the piston 2 rises, and the lever 4 rotates via the operating shaft 3 as the operation plate 7 rises. The master jaw 6 rotates about the fulcrum shaft 5 and the claw 14 grips the workpiece 15.

When the claw 14 comes into contact with the work 15 from both sides, the piston tries to move up further. However, since the distance between the axes of the lever 4 is conventionally fixed, the lever 4 is at the dead center regardless of the size of the work. Even if it is not in the position, the piston 2 stops in the pressed state, so that it is not configured to prevent falling.

However, in this embodiment, the distance between the axes of the lever 4 changes, so that the piston 2 can be stopped at the dead point with certainty, and the operating shafts 3 at both ends of the lever 4 always receive the load of the spring 8. Therefore, the workpiece 15 is securely gripped even when the drive source is stopped.

In addition, when the dimension of the work 15 is extremely large, there is a case where it is attempted to compress more than the allowable compression length of the spring. In this embodiment, the spring guide A9 and the spring guide B10 are equal to or greater than the allowable compression length of the spring. The spring can be prevented from being damaged by abutting before being compressed and acting as a stopper.

The above configuration relates to a toggle type fluid pressure hand that clamps a workpiece by opening and closing a claw with a fluid pressure cylinder. However, the present invention is not limited to the hand, but also for a machine using a toggle mechanism such as a toggle type jig. It is possible to deploy.

Configuration diagram of this example Explanatory drawing when the workpiece of this example is clamped Explanatory drawing which shows the free state of the lever of a present Example Explanatory drawing which shows the compression state of the lever of a present Example. Explanatory drawing showing the combination of a spring Configuration diagram of conventional example Explanatory drawing when clamping a conventional workpiece

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cylinder 2 Piston 3 Actuation shaft 4 Lever 5 Support shaft 6 Master jaw 7 Operation plate 8 Spring 9 Spring guide A
10 Spring guide B
11 axis 12 body
13 Bleed spring 14 Claw 15 Workpiece

Claims (3)

  The operation plate provided at the piston tip of the fluid pressure cylinder and the master jaw that is rotatably connected to the body are rotatably connected at both ends of the lever. In the toggle-type hand gripped by the lever, an operating shaft that constitutes the rotational connection between the operation plate and the master jaw is provided at both ends of the lever, and a spring guide that applies a load in the direction of moving the operating shaft away from each other is installed. A toggle type hand characterized by a spring in between. 2. The toggle-type hand according to claim 1, wherein the spring guide guides the spring so that it does not move, and has a length at which the operating shaft stops at such a length that the spring does not adhere. 3. The toggle-type hand according to claim 1, wherein a plurality of springs are used in combination, and the springs in contact with each other are combined in opposite directions.