JPH0662265B2 - Hand mechanism - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a hand mechanism which is connected to the tip of an arm of a robot and is capable of gripping both a small-diameter work and a large-diameter work having significantly different grip diameters.

[Prior art and its problems]

For workpieces with significantly different gripping diameters, a hand for large diameter workpieces and a hand for small diameter workpieces have been prepared so far, and the hand can be automatically or manually changed according to the gripping diameter. Even if the hand is used or has a double gripper mechanism with two types of grippers for gripping the workpiece, a large diameter work gripper and a small diameter work gripper, swing the large diameter work gripper and small diameter work gripper separately. It was open and closed. For this reason, the hand mechanism becomes complicated and expensive, and particularly in the case of an assembling robot, there is a drawback in that it is difficult to accurately center a large-diameter work and a small-diameter work.

[Object of the Invention]

SUMMARY OF THE INVENTION It is an object of the present invention to eliminate the above-mentioned conventional drawbacks and to provide a hand mechanism which is a double gripper mechanism but has a simple structure and high centering accuracy between a large diameter work and a small diameter work.

[Main points of the invention]

This invention has a hand mechanism that is connected to the tip of an arm of a robot and is capable of gripping workpieces with significantly different grip diameters.
A work having a small grip diameter, which is composed of two clamping members that are connected to the drive member of the first opening / closing cylinder having a drive member that moves back and forth in the axial direction and that opens and closes in the direction perpendicular to the axis and in both sides of the axis. A small-diameter work gripper for gripping the workpiece and a clamping member are each formed in an L shape, and one side end portion of the L-shape is rotatably supported by the respective clamping members of the small-diameter work gripper and the axis line is formed. A large-diameter work gripper that is connected to a driving member of a second opening / closing cylinder arranged on both sides or on the same axis line to open and close in both directions of the axis line and that grips a work piece having a large grip diameter, The gripping center of the small-diameter workpiece and the gripping center of the large-diameter workpiece are made to coincide with each other on the same axis, and the above-mentioned object is achieved.

Example of Invention

1 and 2 show an embodiment of a hand mechanism constructed according to the present invention. FIG. 1 shows an example in which a small-diameter workpiece is grasped, and FIG. 2 shows an example in which a large-diameter workpiece is grasped.

In FIG. 1, a fixing block 1 which forms a base of a hand mechanism and also serves as a connecting member of a robot arm.
A first opening / closing cylinder 2 that is operated by fluid pressure such as air pressure or hydraulic pressure is attached to the inside of the cylinder, and a piston 2a serving as a driving member for opening and closing a small-diameter work gripper to be described later is incorporated inside. A coupling piece 2c is attached to the piston 2a via a piston rod 2b, and a linear movement guide rod 2d is provided at the tip. Reference numeral 4 denotes two side plates fixed to the fixing block 1 by sandwiching the first opening / closing cylinder 2 from the front and back, and a guide block 11 having a guide hole for guiding the guide rod 2d is held at the tip of the side plate. Has been done. In this guide block 11, a guide rail 8 having a guide groove in the horizontal direction in the figure is fixed symmetrically, and a constricting member 7a which constitutes a small-diameter work gripper 7 and clamps and grips the small-diameter work 9 along the guide groove. Moves symmetrically in a straight line. This movement causes the piston 2a of the first opening / closing cylinder 2 to advance and retreat in the axial direction, and the force at the time of advancing and retreating is transmitted to the compressing member 7a via the connecting bar 5, so that a horizontal component force is applied to the compressing member. It is done by making it work.

Reference numeral 6a denotes an L-shaped clamping member for a large-diameter workpiece. One end of the L-shape is rotatably supported by a fulcrum 7b on the clamping member 7a of the small-diameter workpiece gripper. Of the open / close cylinder 2 is pivotally supported so as to be symmetrical with respect to the axis of the open / close cylinder 2, and is housed in the second open / close cylinders 3 arranged on both sides of the first open / close cylinder 2, and by the piston 3a as a drive member, It opens and closes on both sides of the axis via the connecting rod 3b.

When gripping a large-diameter workpiece as shown in FIG. 2, a working fluid is caused to flow into the back surface side of the piston 3a, the connecting rod 3b is projected forward, and the compression member 6a is rotated downward. Since the pressing member 7a for small-diameter workpieces is provided with a stopper 7c for restricting the stationary position of the pressing member 6a for large-diameter workpieces, the pressing member 6a is rotated until it comes into contact with this stopper 7c. In this position, the compression surface 6 of the normal compression member is
There is a gap between b and the large-diameter workpiece 10. Therefore,
When hydraulic oil is caused to flow into the front face side of the piston 2a of the first opening / closing cylinder and the piston is driven upward, the constriction member 7a is pulled inward via the connecting bar 5, and the large-diameter workpiece
Stop when there is no gap between 10 and the pressure surface 6b. Therefore, the clamping force of the pressing member against the large diameter work or the gripping force of the large diameter work gripper is given from the first opening / closing cylinder that acts on the small diameter work gripper.

As described above, the small-diameter work gripper is used not only for gripping the small-diameter work, but also as a supporting member for pivotally supporting the large-diameter work gripper, and is configured to give a gripping force to the large-diameter work gripper. Therefore, it has a structural member and a gripping function necessary for constructing a large-diameter work gripper, and although it is a double gripper mechanism having a large-diameter work gripper and a small-diameter work gripper as a hand mechanism, It is possible to construct a hand mechanism having a small number and a simple structure. Further, according to the mechanism of the present invention, the small-diameter work gripper also functions as a part of the large-diameter work gripper mechanism, and the large-diameter work gripper can be configured symmetrically with the axis of the small-diameter work gripper sandwiched. Therefore, it becomes easy to align the grip center of the small-diameter work with the grip center of the large-diameter work on the same axis within the machining error range, and it is possible to significantly improve the centering accuracy of the large-diameter work and the small-diameter work. It will be possible.

In the above description, both the first opening / closing cylinder and the second opening / closing cylinder are operated by fluid pressure. However, a screw rod provided on the same axis is rotatably driven by the rotor of the electric motor. It is also possible to use an electric cylinder that drives the gripper to open and close by advancing and retracting a nut screwed to the screw rod. Therefore, the driving member at this time is a nut screwed to the screw rod.

Further, in the above description, the second opening / closing cylinder is made up of two cylinders arranged on both sides of the first opening / closing cylinder.
Obviously, the object of the present invention can be achieved even with a single cylinder arranged on the same axis as the opening / closing cylinder and between the first opening / closing cylinder 2 and the fixing block 1.

[Advantages of the Invention] As described above, according to the present invention, as a mechanism of a hand capable of gripping a work having a significantly different gripping diameter, the first opening / closing cylinder including a drive member that advances and retracts in the axial direction. A small-diameter work gripper that is connected to the drive member and that opens and closes in the direction perpendicular to the axis and in both sides of the axis, and L-shaped one-side end portion of each of the L-shaped work grippers. Are rotatably supported by the respective pressing members of the small-diameter work gripper, and are connected to drive members provided on both sides of the axis or on a second opening / closing cylinder arranged on the same axis to connect both sides of the axis. Since the double gripper mechanism has a structure that includes a large diameter work piece that is opened and closed in two directions, the small diameter work gripper also serves as a part of the constituent members of the large diameter work gripper. It is possible to construct a hand mechanism having a small number of materials and a simple structure. Further, since the rotation center of the large diameter work gripper is provided on the small diameter work gripper, the grip center of the water diameter work gripper and the grip center of the small diameter work gripper are
It is possible to accurately match these within the error range of the work when manufacturing these grippers, and especially in the assembly robot, the centering accuracy of the large diameter work and the small diameter work is easy and the conventional large diameter work gripper and small diameter work gripper The effect that it can be remarkably improved as compared with the double gripper mechanism in which and swing separately is obtained.

[Brief description of drawings]

FIGS. 1 and 2 are views showing an embodiment of a hand mechanism constructed according to the present invention. FIG. 1 is a front view showing a situation when a small-diameter workpiece is gripped, and FIG. It is a front view showing a situation when a large-diameter work is grasped. 2 ... First opening / closing cylinder, 3 ... Second opening / closing cylinder, 5 ... Connecting bar, 6 ... Large diameter work gripper, 6a
…… Clamping member, 7 …… Small diameter work gripper, 7a …… Clamping member, 9 …… Small diameter work piece, 10 …… Large diameter work piece.

Claims (1)

[Claims] 1. A drive mechanism of a first opening / closing cylinder, which is a mechanism of a hand which is connected to the tip of an arm of a robot and is capable of gripping a work having a significantly different grip diameter, and which has a drive member which moves back and forth in an axial direction. And a small-diameter work gripper for holding a work having a small gripping diameter, which is composed of two clamping members which are connected to each other and open and close in a direction perpendicular to the axis and in both directions of the axis, and each of which has an L-shape. One end of the L-shape is rotatably supported by the respective pressing members of the small-diameter work gripper, and a driving member provided in a second opening / closing cylinder arranged on both sides of the axis or on the same axis. And a large-diameter work gripper that is opened and closed in both directions of the axis and grips a workpiece with a large grip diameter, and the grip center of the small-diameter work and the grip center of the large-diameter work are on the same axis. Hand mechanism, wherein the door.