JPH0655480A - Industrial robot hand - Google Patents

Abstract

PURPOSE:To grip a substance easily and securely by increasing the gripping force in the area near the gripping position while increasing the movements of the fingers in the area other than the area where the gripping force is increased, by connecting links with pins between a driving piece and the base ends of the fingers. CONSTITUTION:A double action pneumatic cylinder 10 is installed demountable to the hand 8 of an industrial robot through a flange coupling 9. And a connecting member 14 is fixed to the piston rod 13 of the cylinder 10 so as to compose a driving piece 15. Furthermore, a pair of fingers 18 and 19 are provided displaceable to a holding body 11 fixed to the cylinder 10, and the tips 20 and 21 of the fingers 18 and 19 are moved in the approaching directions each other, so as to grip a substance 24. And a pair of intermediate links 28 and 29 are connected with pins 30 to 33 to the connecting member 14 and the base ends 26 and 27 of the fingers 18 and 19. Consequently, while the gripping force is increased in the area near the gripping position, the movements of the fingers 18 and 19 are increased at the area other than the area where the gripping force is increased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hand mounted on the hand of an industrial robot.

[0002]

2. Description of the Related Art A typical prior art is shown in FIG. A pair of fingers 1 are provided on a support body 3 by a pin 2 so as to be capable of swinging displacement, a cam groove 4 is formed in these fingers 1, and a pin 5 as a follower is fitted in the cam groove 4. The pin 5 is driven to reciprocate up and down in FIG. 7 by the cylinder 6 fixed to the support 3. Support 3
Is attached to the hand 7 of the industrial robot.

[0003]

In the prior art shown in FIG. 7 as described above, the displacement of the pin 5 driven by the cylinder 6 is converted into the displacement of the finger 1 by the action of the cam groove 4, and thereby the finger 1 is displaced. A relatively small gripping force of 1 is obtained as uniformly as possible over the entire angular displacement movement of the finger 1. However, the object can be easily
Moreover, in order to surely hold the object, when the object is held by the fingertip of the finger 1, the gripping force is increased near the gripping point by the finger 1, and the movement displacement amount of the finger 1 is small at this time. Alternatively, the displacement amount, that is, the movement of the finger 1 is desired to be large in a range in which the object is not gripped by the finger 1.

Further, the structure shown in FIG. 7 has a large weight as compared with the gripping force.

An object of the present invention is to provide a hand of an industrial robot in which the gripping force is increased near the gripping point of the finger and the movement of the finger is increased in other ranges.

[0006]

According to the present invention, there is provided a drive source which is provided in a hand of an industrial robot and which reciprocally displaces a drive piece, a support body provided in the hand, and a support body in a displacement direction of the drive piece. A hand of an industrial robot, which is provided so as to be displaceable in a vertical direction, and includes a pair of fingers for gripping a work, and a pair of links pin-coupled to a drive piece and a base end portion of the finger. is there.

The present invention is also characterized in that the pair of fingers are guided by the support so as to be displaced in parallel.

[0008]

According to the present invention, a hand of an industrial robot is provided with a drive source such as a cylinder and a support, and a pair of fingers for gripping a work is provided on the support as a drive piece. Displaceable in the direction perpendicular to the displacement direction,
The drive piece of the drive source can be pin-coupled to the base end of the finger via the links, respectively, to increase the gripping force near the displacement position of the finger when gripping an object with the finger, that is, near the gripping point. In other ranges, it is possible to increase the displacement amount of the finger. In other words, the relationship between the gripping force of the fingertip and the stroke of the fingertip, that is, the amount of displacement is based on the principle of virtual work. When it is increased, the gripping force is decreased. Therefore, the finite work obtained from the drive source can be used for a high gripping force near the gripping point and for a large stroke of the finger in other ranges.

[0009]

1 is a side view of a hand 36 according to an embodiment of the present invention, FIG. 2 is a plan view of the embodiment, and FIG. 3 is a front view of the embodiment. With reference to these drawings, a double-acting pneumatic cylinder 10 is detachably fixed to a hand 8 of an industrial robot having 6 axes by a flange joint 9, and a support 11 is fixed to the cylinder 10. .
The cylinder 10 has a piston rod 13, to which a connecting member 14 is fixed.
3 and the connecting member 14 form a driving piece 15. Support 1
A pair of fingers 18 and 19 are displaceably provided on the device 1.
By moving the fingertips 20 and 21 of the fingers 18 and 19 toward each other as shown by arrows 22 and 23,
The object 24 can be gripped. Connecting member 14 and finger 1
A pair of intermediate links 28 and 29 are pin-coupled to the base ends 26 and 27 of 8 and 19 by pins 30, 31 and 32 and 33, respectively. Supports 11 are provided in pairs on the left and right in FIG. 3, spacers 34 and 35 are interposed, and fingers 18 and 19 are arranged between the supports 11 forming a pair. The hand 36 is configured symmetrically with respect to a plane that passes through the axis 37 of the cylinder 10 and is perpendicular to the plane of FIG.

FIG. 4 is a sectional view taken along section line IV-IV in FIG. The ridges 45 and 46 formed on the fingers 18 and 19 are slidably fitted in the recessed grooves 44 formed in the pair of supports 11 and aligned in the vertical direction in FIG. Ridge 45,
46 extends in a straight line in the vertical direction of FIG. 1 and in the direction perpendicular to the plane of FIG. As a result, the fingertips 20 and 21 of the fingers 18 and 19 remain parallel to each other and the piston rod 13
Can be displaced in the direction of approaching each other as indicated by arrows 22 and 23.

FIG. 5 is a graph showing the characteristics of the embodiment shown in FIGS. The horizontal axis of FIG. 5 represents the amount of displacement of the piston rod 13 of the cylinder 10 to the right in FIG.
The vertical axis represents the amount of vertical displacement of the fingertips 20 and 21 of the finger 18 in FIG. 1, that is, the stroke.
Shown by 9. The other line 40 shows the gripping force by the fingertips 20 and 21 when the vertical axis of FIG. 5 is the force. In the vicinity of the gripping point of the object 24 by the fingertips 20 and 21, the gripping force is large as indicated by the line 40.
The rate of change dy / dx of the vertical displacement y of 8 and 19 is small.
The range near this gripping point is indicated by reference numeral W1. In the range W2 other than the vicinity W1 of the gripping point, the gripping force is small as shown by the line 40, but is large as shown by the line 39. Therefore, a large stroke is obtained for the fingertips 20 and 21, and dy / dx is large. .

In the range W1 near the gripping point where the object 24 is gripped by the fingertips 20 and 21 in this manner, the link 2
The angle α formed by the straight line connecting the pins 30 and 32 of No. 8 and the axis line 37 is configured to be a value near 90 degrees, and the links 28 and 29 are close to the axis line 37 near the gripping point. By this state, the displacement amount of the fingertips 20 and 21 becomes small. Since the work per unit displacement of the piston rod 13 of the cylinder 10 is constant, the gripping force N becomes large according to the principle of virtual work. Conversely, the range W other than the gripping point
2, the angle α is relatively small, and therefore the displacement of the fingertips 20 and 21 with respect to the constant displacement of the piston rod 13 is increased.

FIG. 6 is a side view of another embodiment of the present invention. This embodiment is similar to the previous embodiment, and the corresponding parts bear the same reference numerals. In the embodiment shown in FIGS. 1 to 4 described above, the fingertips 20 and 21 of the fingers 18 and 19 are displaced toward each other when the piston rod 13 is extended, as indicated by arrows 22 and 23. However, in the embodiment shown in FIG. 6, the extension of the piston rod 13 causes the fingertips 20, 21 to move away from each other as indicated by the arrows 22a, 23a. The object is displaced and comes into contact with the inner wall of the object 24a and grips it. In order to achieve this action, the links 28, 29 are connected to the fingers 18,
Located on opposite sides of each other with respect to 19, ie (upper and lower in FIG. 6), they are pin-coupled to the connecting member 14. Other configurations are similar to those of the above-described embodiment.

Instead of the piston 10, another drive source having a motor or the like and displacing the drive piece 15 in the left and right directions of FIGS. 1 and 6 may be used.

[0015]

As described above, according to the present invention, a drive source and a support are provided on the hand of an industrial robot, and a drive piece of the drive source and a base end portion of a pair of fingers supporting a work are provided. By pin-linking each link in between, the gripping force can be increased near the gripping point and the finger movement can be increased in other ranges, so that the object can be gripped with a large gripping force. At the same time, when the object is not grasped, the displacement amount of the finger can be increased and the object can be grasped easily.

In particular, according to the present invention, by moving the fingers in parallel, it is possible to reliably grip an object by, for example, surface contact.

[Brief description of drawings]

FIG. 1 is a side view of an embodiment of the present invention.

FIG. 2 is a plan view of the hand 36 shown in FIG.

3 is a front view of the hand 36 shown in FIGS. 1 and 2. FIG.

FIG. 4 is a sectional view taken along the section line IV-IV in FIG.

FIG. 5 is a diagram showing the characteristics of the embodiment shown in FIGS.

FIG. 6 is a side view of another embodiment of the present invention.

FIG. 7 is a side view of the prior art.

[Explanation of symbols]

 8 Industrial Robot Hand 10 Double-acting Pneumatic Cylinder 11, 12 Support 13 Piston Rod 14 Connecting Member 15 Drive Piece 18, 19 Finger 20, 21 Fingertip 26, 27 Base End 28, 29 Link

Claims (2)

[Claims] 1. A drive source provided on a hand of an industrial robot, which reciprocally displaces a drive piece, a support provided on the hand, and a support provided on the support so as to be displaceable in a direction perpendicular to a displacement direction of the drive piece. A hand of an industrial robot, comprising a pair of fingers for gripping a work, and a pair of links that are pin-coupled to a drive piece and a base end portion of the fingers. 2. The hand of the industrial robot according to claim 1, wherein the pair of fingers are guided by the support so as to be displaced in parallel.