JPH0735740Y2 - Robot hand - Google Patents

Description

[Detailed description of the device] A. Industrial application field This device is used for work supply work, pick and press work, etc. in automatic assembly lines, automatic inspection lines, etc. The present invention relates to a robot hand that moves and grips an object to be gripped.

B. Conventional Technology A conventional robot hand of this type is shown in FIGS. A piston 2 that is slidable in the vertical direction is provided inside a cylinder 1 that is a hand body, and a piston rod 3 that is integral with the piston 2 projects to the outside of the cylinder 1. Racks 3 are provided on the left and right sides of the lower end of the piston rod 3.
1,32 are formed, and at the bottom of the cylinder 1, this rack 31,3
Pinions 5 and 6 that mesh with 2 are pivotally supported. The arms 7 and 8 are guided and supported by the cylinder 1 so as to be slidable in the direction orthogonal to the reciprocating direction of the piston 2, and the racks 71 and 81 engraved at the base end mesh with the pinions 5 and 6. is doing. And
Grasping claws 72, 82 are attached to the tip portion thereof.

Also, the lower cylinder chamber 1a partitioned by the piston 2
A compression coil spring 9 is provided in the compression coil spring 9, and the restoring force of the compression coil spring 9 constantly urges the piston 2 in the upward direction, that is, in the direction of retracting the piston rod 3.

Then, fluid pressure such as compressed air or pressure oil is supplied to the upper cylinder chamber 1b. Below, it demonstrates as what supplies compressed air.

To lift the work 10 with this robot hand, place the work 10 between the grip claws 72 and 82 and then
Compressed air is supplied to b to extend the piston rod 3. The extension of the piston rod 3 rotates the pinions 5 and 6, respectively, the arm 7 moves to the right in FIG. 8 and the arm 8 moves to the left, and as shown in FIG. Thus, the work 10 is gripped.

Then, after moving the entire robot hand and moving the work 10 to a predetermined position, if the upper cylinder chamber 1b is decompressed, the restoring force of the compression coil spring 9 causes the piston rod 3 to retract and the pinions 5 and 6 differ from the above. Since the gripping claws 72 and 82 rotate in the opposite direction, they are separated from the work 10.

C. Problems to be Solved by the Invention The conventional robot hand thus configured has the following problems.

As shown in FIG. 9, the gripping force when gripping the work 10 from the outside depends on the fluid pressure such as compressed air supplied to the upper cylinder chamber 1b. It is possible to obtain a good gripping force. On the other hand,
As shown in FIG. 10, when the work 10 is gripped from the inside, the gripping force is obtained only by the restoring force of the compression coil spring 9. Therefore, when the work weight becomes heavy, the work cannot be gripped.

In order to deal with workpieces of various shapes and weights, robot hands that can exchange the outer gripping hand and the inner gripping hand according to the workpiece, or a parallel movement type robot hand with a double-acting cylinder are conventionally used. It was being done.
However, the former one is troublesome to replace, and the latter one is complicated and expensive.

An object of the present invention is to provide a parallel movement type robot hand using a single drive source, which is capable of gripping a work of the same weight from the outside and the inside.

D. Means for Solving Problems In order to achieve such an object, the robot hand of the present invention has a cylinder formed inside the hand body and having a piston slidably accommodated therein, and a cylinder inside the cylinder. A piston rod that expands by supplying a fluid to apply a fluid pressure to the piston, a compression coil spring that biases the piston rod in a direction opposite to the fluid pressure, and a pair of racks formed on the piston rod, A pair of pinions that mesh with this rack and transmit the displacement of the piston in a direction perpendicular to the piston rod by rotating in opposite directions, and a pair of pinions that mesh with the pair of pinions and the displacement of the piston rod is orthogonal to the piston rod. A pair of arms engraved with racks for transmitting in the direction, a first grip claw fixed to one of the pair of arms, and a first grip. A third gripping claw integrally provided with the claw; and a second gripping claw fixed to the other of the pair of arms and moving between the first gripping claw and the third gripping claw. , The first grip claw and the second
When the fluid pressure acts on the piston, the gripping claws of the second gripping claw and the third gripping claw are close to each other due to the biasing force of the compression coil spring. Are separated from each other when
The second gripping claw and the third gripping claw, which are configured to approach each other by the biasing force of the compression coil spring, grip the workpiece from the outside by the first gripping claw and the second gripping claw that approach each other, and separate from each other. The work is grasped from the inside by the grasping claws.

E. Action When a single drive source is driven in the first direction, the first and third grip claws move integrally in one direction and the second grip claw moves in the other direction. When grasping an object to be grasped from the outside, the object to be grasped is placed between the first grasping claw and the second grasping claw, and the first grasping claw and the second grasping claw approach each other. By doing so, the object to be grasped is grasped between the first grasping claw and the second grasping claw. On the other hand, when the object to be grasped is grasped from the inside thereof, the object to be grasped is placed between the second grasping claw and the third grasping claw, and the drive source is driven in the same direction as described above, so that the second direction is obtained. The grasping claw and the third grasping claw are separated from each other, whereby the object to be grasped is grasped between the second grasping claw and the third grasping claw.

F. Embodiment An embodiment of the robot hand according to the present invention is shown in FIGS. Referring to FIGS. 1 to 3, reference numeral 21 is a cylinder constituting a hand main body, and a piston 22 is housed so as to be slidable in the vertical direction in FIG. In the lower cylinder chamber 23 of the cylinder 21 partitioned by the piston 22, a compression coil spring 24 is attached to the piston rod 25.
The restoring force of the compression coil spring 24 causes the piston 22 to always move upward, that is, the piston rod 25.
It is urged to move in the degenerate direction. Cylinder 21
Compressed air is supplied to the upper cylinder chamber 26.

A rack 251 is formed at the tip of the piston rod 25,
Pinions 28 and 29 that mesh with the rack 251 are rotatably supported by the cylinder 21. Also, 30 and 40 are arms,
It has racks 30a, 40a that mesh with the above-mentioned pinions 28, 29, and is fitted in the guide portion 21a of the cylinder 21 so as to be movable in the direction orthogonal to the moving direction of the piston 22, that is, in the left-right direction in FIG. (See Figure 2). As shown in FIG. 3, a rod-shaped mounting member 31 is fixed to the arm 30, and a first grip claw 32 is provided on a side portion of the mounting member 31, and the first grip claw 32 is provided. From the bar across arms 30 and 40
33 and 34 extend, and a third grip claw 35 that faces the first grip claw 32 is provided at the end thereof. On the other hand, the arm 40 is provided with a second grip claw 42 via a mounting member 41, and as can be seen from FIG. 3, the second grip claw 42 has the first grip claw 32 and the third grip claw 42. It is provided at a position where it can move between the grip claw.

The cylinder 21, the piston 22, the piston rod 25, the rack 251, and the pinions 28, 29 constitute a single drive source.

Next, the operation will be described with reference to FIGS. 4 and 5.

When compressed air is supplied to the upper cylinder chamber 26, the piston
The pressure applied to 22 causes the piston 22 to move downward against the restoring force of the compression coil spring 24, which causes the piston rod 25 to extend. By the extension of the piston rod 25, the pinions 28 and 29 meshing with the rack 251 rotate in mutually opposite directions, and the arms 30 and 40 move in opposite directions in conjunction with this rotation. That is, the arm 30 moves to the left in the first illustration (arrow A) and the arm 40 moves to the right (arrow B). The first to third gripping claws 32, 35, 42 move together with the arms 30, 40, and when the arms 30, 40 move the most, the positional relationship between the gripping claws 32, 35, 42 is the first. It becomes as shown in FIG. On this move,
As can be seen from FIGS. 4 and 5, the first grip claw 32
The distance between the second grip claw 42 and
And the distance between the third grip claw 35 becomes long. Therefore, the work that must be held on the outer peripheral surface can be held by the first grip claw 32 and the second grip claw 42, and the work that must be held on the inner peripheral surface can be held by the second grip claw 42. It can be held by the third grip claw 35. In either case, the work gripping force is due to the pressure applied to the piston 22 by compressed air or the like.

Then, if the upper cylinder chamber 26 is decompressed after the gripped work is conveyed to a predetermined position, the piston 22 slides upward due to the restoring force of the compression coil spring 24, which causes the piston rod 25 to retract and the arm. Since the work pieces 30, 40 move in the opposite direction, the work can be released.

In the embodiment shown in FIG. 6 and FIG. 7, the supporting projection 36 is provided on the work gripping surface of the first to third gripping claws 32, 35, 42, and the work is supported at three points. As a result, stable gripping performance can be obtained. It is even more effective if the convex portion 36 is made of a material having a large friction coefficient such as rubber.

In the embodiment described above, the first and second grip claws 32, 4
Although 2 is shown provided via the arms 30 and 40, the tips of the arms 30 and 40 themselves may have the function of a grip claw.

G. Effect of the Invention Since the present invention is configured as described above, it is possible to use the grasping pawls when grasping a work without exchanging the grasping pawls or using the double-acting cylinder. It can be gripped, or can be gripped on the inner peripheral surface, and in any of them, a gripping force can be obtained by fluid pressure, and a workpiece having a larger weight than the gripping force obtained by the spring force can be gripped.

[Brief description of drawings]

1 is a front view of the robot hand before the arm is actuated, a part of which is cut away, FIG. 2 is a right side view thereof, and FIG. 3 is a sectional view taken along line III-III of FIG. 4 is a front view after the arm is actuated, a part of which is cut away, and FIG. 5 is a sectional view taken along line VV of FIG. 6 and 7 show another embodiment. FIG. 6 is a front view of the robot hand, and FIG. 7 is a sectional view taken along the line VII-VII in FIG. FIG. 8 is a front sectional view of a conventional robot hand using a single-acting cylinder. FIG. 9 is a diagram for explaining a case where a work is gripped outside,
FIG. 10 is a diagram for explaining the case of holding inside. 21: Cylinder, 22: Piston 24: Compression coil spring, 25: Piston rod 30,40: Arm, 31: Mounting member 32: First gripping claw 35: Third gripping claw 42: Second gripping claw

Claims (1)

[Scope of utility model registration request] 1. A cylinder formed inside a hand main body, in which a piston is slidably accommodated, a piston rod which is extended by supplying fluid into the cylinder and applying fluid pressure to the piston, A compression coil spring for urging the piston rod in the direction opposite to the fluid pressure, a pair of racks formed on the piston rod, and the pistons are displaced in the piston rod by meshing with the racks and rotating in opposite directions. On the other hand, a pair of pinions that transmit in the vertical direction, a pair of arms that engage with the pair of pinions, and a rack that engraves the rack that transmits the displacement of the piston rod in a direction orthogonal to the piston rod, and one of the pair of arms. The fixed first grip claw, the third grip claw integrally provided with the first grip claw, and the third grip claw fixed to the other of the pair of arms A second gripping claw that moves between a first gripping claw and a third gripping claw, wherein the first gripping claw and the second gripping claw have a fluid pressure acting on the piston. Sometimes they approach each other and are separated from each other by the biasing force of the compression coil spring, and the second gripping claw and the third gripping claw are separated from each other when fluid pressure acts on the piston, and the biasing force of the compression coil spring is applied. Are configured so as to approach each other, and the first gripping claw and the second gripping claw that approach each other grip the work from the outside, and the second gripping claw and the third grip claw that separate from each other hold the work. A robot hand characterized by being gripped from the inside.