JPH08281586A - Work holding hand - Google Patents

Abstract

PURPOSE: To continue an operation without changing a hand even in the case of changing a work by arranging a plurality of coaxial pins capable of being inserted and drawn against a positioning hole, and letting differ the fitting diameters of these pins to the positioning hole from each other. CONSTITUTION: When a work 51 of which the bore of a positioning hole 51a is smaller than a work 52 is handled, a hand 1 is approached to the work 51, the work 51 is positioned by means of a second pin 7 which is smaller in diameter than a first pin 6 for the work 52 and can be inserted in the positioning hole 51a, and in addition the work 51 is held together with a clamp arm 2. At such inserting, the lower end of the first pin 6 is in the condition of being not run against the work 51, and the seating face of the second pin 7 is put on the surface of the work 51. In this way, by selecting and using either of the first and second pins 6, 7 of which the outer diameter of respective fitting faces 6e, 7b are different from each other, two sorts of the works 51, 52 can be held without exchanging the hand 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hand for holding a work provided on an industrial robot, and more particularly to a hand for holding a work which can reliably position and hold different kinds of works.

[0002]

2. Description of the Related Art Hands mounted on an industrial robot as an automatic exchange system are equipped with dedicated tools for each, and for example, hold a work after casting and divide the work into a sprue and a product part. For this reason, there is a device that can be positioned with respect to a cutting machine and set a product in the stocker after cutting.

In such a hand for holding a work,
In order to position the posture of the work, a pin to be inserted into a positioning hole formed in the work itself is provided and a clamper for holding the work is provided. The pin advances with respect to the work and enters the positioning hole, and by holding the pin in this state by the clamper, the work can be positioned and set on the hand. The pin functions not only as a positioning member but also as a member for restraining the work together with the clamper.

[0004]

The positioning holes provided in the workpieces vary depending on the shape and weight of each workpiece. For example, when the work is large and heavy, it is necessary to increase the inner diameter of the positioning hole and thicken the pin that enters the hole to stabilize the positioning.

However, when the inner diameter of the positioning hole changes in this way, it is necessary to prepare a large number of hands having pins capable of coping with this. For this reason, in the case of high-mix low-volume production, the cost required for the hand increases, and the obstacle in terms of cost increases.

If the type of the positioning hole changes each time the work is changed, the hand itself must be replaced accordingly. For this reason, even in the case of processing using a robot, the work of exchanging the hand for the robot is frequently added, and even if the automatic tool change function is provided, the time spent for the hand exchange is increased. It will be long and the impact on productivity is inevitable.

The problem to be solved in the present invention is to provide a hand for gripping a work which can continue the work without exchanging the hand even if the work is changed.

[0008]

According to the present invention, a clamp mechanism for exerting a restraining force on a workpiece toward a robot arm, and a positioning hole formed on a surface of the workpiece facing the robot arm are positioned. A hand comprising a positioning / constraining unit for gripping the work together with the clamping mechanism, wherein the positioning / constraint unit is provided with a first pin insertable into the positioning hole and coaxially arranged with the first pin. And a movable second pin that protrudes and retracts from the first pin and can be inserted into and removed from the positioning hole, and the fitting diameters of the first and second pins in the positioning hole are different. Characterize.

[0009]

[Function] For a work having a positioning hole that matches the fitting diameter of the first pin of the positioning / constraining unit, the posture of the work is set together with the clamping mechanism by inserting the first pin into the positioning hole. Can be gripped. Further, in the case of a work having a positioning hole that matches the fitting diameter of the second pin, the work can be gripped together with the clamping mechanism by projecting the second pin beyond the first pin.

Therefore, even if the inner diameter of the positioning hole, which is appropriate for the shape and weight of the work, is changed,
If there are two types of works having positioning holes corresponding to the fitting diameter of the second pin, it is possible to perform a gripping operation for these works without exchanging the hands.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a front view of a main part when a work holding hand of the present invention is attached to a robot arm, and FIG. 2 is a right side view of FIG.

In FIG. 1, two works 51, 52 are provided.
Are shown together on the left and right, and either one of these works 51, 52 is actually attached to or detached from the hand. And these works 51 and 52 are 2 respectively.
The positioning holes 51a and 52a are opened at the positions, and two positioning holes 51 are provided for each of the works 51 and 52.
The distance between a and 52a is common.

The robot arm 20 is provided with an automatic tool changing device 21 at the tip thereof, and the hand 1 is detachably attached to the automatic tool changing device 21. The hand 1 includes a connector 1a connected to the automatic tool changer 21 and a base 1b connected to the connector 1a. The base 1b is provided with a pair of clamp arms 2 as a clamp mechanism. The connector 1a is provided with a pair of positioning and Positioning and restraint unit 3 for restraint
Are provided respectively.

The base 1b is movable in the vertical direction in the figure with respect to the connector 1a, and is connected to a drive source for driving the movement of the base 1b by coupling the connector 1a with the automatic tool changer 21. Further, the clamp arm 2 is connected to the rod 2b of the cylinder 2a provided on the base 1b, and the clamp arm 2 can be moved left and right by the advancing / retreating operation of the rod 2b as shown in FIG.

The positioning / constraining unit 3 is a work 5
Simultaneously with the positioning of 1, 52, the upper and lower surfaces of these works 51, 52 can be restrained and held together with the clamp arm 2 as shown in FIG. As shown in FIG. 3, the positioning / restraining unit 3 includes a cylinder 4 fixed to the connector 1a and a cylindrical sleeve 5 protruding from the lower end of the cylinder 4.

A flange 6a provided on the upper end of the cylindrical first pin 6 is fixed to the lower end of the sleeve 5 by a bolt 6b. As shown in FIGS. 3 and 4, the first pin 6 has a tapered surface 6c formed at the lower end thereof, and three slits 6d are axially cut in a portion excluding the flange 6a to form an outer peripheral surface. The fitting surface 6e is fitted into the positioning hole 52a on the workpiece 52 side shown in FIG.

Further, the rod 4a of the cylinder 4 is coaxially arranged in the sleeve 5, and is arranged so as to be inserted in the cylindrical first pin 6 so that the rod 4a
The second pin 7 is fixed to the lower end of a.

As shown in FIG. 4, the second pin 7 has a planar shape that passes through the slit 6d of the first pin 6, and is movable with the rod 4a with respect to the fixed first pin 6. is there. The rod 4a is attached to the lower end of the second pin 7.
A tapered guide 7a that also serves as a connecting member with is provided with an annular seating surface 7b that abuts on the upper surface of the work 51 on the upper end side, and the fitting surface 6e of the first pin 6 is formed inside thereof. A fitting surface 7c slightly smaller than the outer diameter is provided.

In the above structure, the second pin 7 is used for the positioning hole 51a of the work 51, and when the work 52 is handled in place of this, the fitting surface 6e is fitted into the positioning hole 52 in alignment with the work. The second pin 6 having is used.

In the case of the work 51, as shown in FIG. 5, the rod 4a of the cylinder 4 is retracted, and the hand 1 is operated by the robot arm 20 while aligning the first pin 6 with the positioning hole 52a, and the taper is tapered. The fitting surface 6e is inserted into the positioning hole 52a using the copying by the surface 6c. At this time, since the outer diameter of the fitting surface 7c of the second pin 7 is smaller than that of the fitting surface 6e of the first pin 6, there is no interference with the positioning hole 52a.

The first pin 6, as shown in FIG.
The seating surface 7b of the pin 7 is inserted into the positioning hole 52a until it abuts on the surface of the work 52. As a result, the upper surface of the work 52 is constrained in the vertical direction and the horizontal direction.
Then, as shown in FIG. 1, the clamp arm 2 is moved by the cylinder 2a, and the base 1b is attached to the connector 1.
The work 52 can be held by being held by the clamp arm 2 and the seating surfaces 7b of the first pin 6 and the second pin 7 by being pulled toward the side a.

Further, the inner diameter of the positioning hole 51a is the work 5
When handling a work 51 smaller than 2, the hand 1 is brought close to the work 51 in the same manner as in the previous example, and as shown in FIG. 3, the hand 1 has a smaller diameter than the first pin 6 and is positioned in the positioning hole 51a. The work piece 51 is held together with the clamp arm 2 while being positioned by the insertable second pin 7.

In this operation, the cylinder 4 is operated so that the rod 4a thereof is advanced, and the second pin 7 is moved as shown in FIG.
Is inserted into the positioning hole 51a. At the time of this insertion, as shown in the drawing, the lower end of the first pin 6 does not abut the work 51, and the seating surface 7b is brought into contact with the surface of the work 51 to move the clamp arm 2 and move the base 1b. The work 51 can be held by the pulling operation to the connector 1a side.

In this way, the respective mating surfaces 6e, 7b
By selecting and using either of the first and second pins 6 and 7 having different outer diameters, it is possible to grip the two types of works 51 and 52 without exchanging the hand 1. For this reason, in machining work on a plurality of types of works, the inner diameters of the positioning holes, which are optimal for the size and weight of these works, are two types corresponding to the first and second pins 6 and 7. If so, the hand 1 can be continuously used without being replaced.

Even if the positioning holes have a large number of two or more, if the hand 1 is provided with pins having an outer diameter corresponding to each of them, the workpiece to be machined also corresponds to these pins. It is possible to continue the work without exchanging the hand 1 by selecting the two types of work to be performed.

[0026]

According to the present invention, it is possible to select and operate either the first pin or the second pin which can correspond to the positioning hole which differs depending on the specifications of the work, so that the hand mounted on the robot side can be operated. Since it is not necessary to replace it every time, the work load is reduced and workability is improved.

Further, since one hand can be applied to various works, the number of hands to be prepared can be reduced, the management thereof can be simplified, and the equipment cost can be reduced.

[Brief description of drawings]

FIG. 1 is a front view showing an example in which a hand for gripping a work according to the present invention is attached to a robot arm, and a state in which two works are respectively gripped is shown together.

FIG. 2 is a view corresponding to the right side view of FIG.

FIG. 3 is a partially cutaway view of an essential part showing insertion and restraint of a second pin into a positioning hole of a work.

FIG. 4 is a bottom view showing the positional relationship between the first and second pins.

FIG. 5 is a partially cutaway view of a main part showing insertion into a positioning hole when a second pin is used.

[Explanation of symbols]

 1 Hand 1a Connector 1b Base machine 2 Clamp arm 2a Cylinder 3 Positioning restraint unit 4 Cylinder 4a Rod 5 Sleeve 6 1st pin 6a Flange 6c Tapered surface 6d Slit 6e Mating surface 7 Second pin 7a Guide 7b Seating surface 7c Fitting Mating surface 20 Robot arm 21 Automatic tool changer 51 Work piece 51a Positioning hole 52 Work piece 52a Positioning hole

Claims (1)

[Claims] 1. A clamp mechanism for exerting a restraining force on a workpiece toward a robot arm and a positioning hole formed in a surface of the workpiece facing the robot arm and gripping the workpiece together with the clamp mechanism. A positioning / constraining unit, wherein the positioning / restraining unit is provided with a first pin insertable into the positioning hole, and arranged coaxially with the first pin and protruding from and retracting from the first pin. A hand for gripping a work, comprising a movable second pin that can be inserted into and removed from the positioning hole, and different fitting diameters of the first and second pins into the positioning hole.