JPH08126987A - Rotary shaft transmitting mechanism of robot hand - Google Patents

Abstract

PURPOSE: To provide a rotary shaft transmitting mechanism of a robot hand which can prevent a breakage of the robot when an excessive load is applied to the robot hand, and can reopen the working by repairing the breakage by a worker when the breakage is generated. CONSTITUTION: A robot hand 35 is held by the tip of an arm 33 in order to feed a plate member to a press brake (plate member process machine) 1. A torque is transferred from a driving motor to a driving side bevel gear and a rotary shaft through a playable driven side bevel gear 75. A ball 79 projected at the driven side bevel gear 75 is fitted to a recess 83 provided to a ball guide plate 81, and the torque is transmitted through the ball guide plate 81 and a leaf spring (an elastic body) 89 fixed to the rotary shaft 43. The ball 79 is set to prevent its removal from the recess by the function of the leaf spring 89. When an excessive torque is operated to the robot hand 35, the ball 79 is removed from the recess 83 of the ball guide plate 81, and a rotation-free condition is generated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotation axis transmission mechanism of a robot hand, and more particularly to a rotation axis transmission mechanism of a robot hand which does not transmit an excessive rotation force acting on the robot hand to the robot. is there.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 6, a plate material processing machine such as a press brake 1 may be equipped with a robot 3 for handling a work.

In the press brake 1, left and right C-shaped side frames 5 are integrally connected by an upper frame 7 and a lower frame 9. A punch 11 is removably mounted on the lower end of the upper frame 7, and a die 13 is removably mounted on the upper end of a ram 15 which is movable up and down so as to face the punch 11. Further, the NC device 1 for controlling the press brake 1 on the front surface of the upper frame 7 and the robot 3 mounted in front of the press brake 1
7 are provided.

Therefore, the robot 3 is operated by the control of the NC device 17 to grip the plate material W and carry the plate material W into a predetermined position, and the NC device 17 controls the elevation of the ram 15 to move the punch 11 and the die 13. The plate material W is bent by cooperation.

A back gauge 19 for positioning the plate material W is provided on the press brake 1 behind the die 13 (on the left side in FIG. 6) so as to be movable and positionable in the front-rear direction (L-axis direction). Butt 2 to 19
1 is provided so as to be movable in the up-down direction (Z-axis direction) and the left-right direction (direction orthogonal to the paper surface in FIG. 6).

The work handling robot 3 in front of the press brake 1 is attached to a base plate 23 integrally attached to the lower frame 9. The base plate 23 extends in a rail shape along the longitudinal direction of the die 13 (Y-axis direction), and the robot 3 is moved and positioned in the left-right direction (Y-axis direction) along the base plate 23 by the Y-axis servomotor 25. It

The robot 3 has a fan-shaped member 27 whose upper side is widened in the front-rear direction (L-axis direction), and on this fan-shaped member 27, a movable table 29 is provided so as to be movable in the L-axis direction.

The movable table 29 is provided with a column member 31 which can be raised and lowered in a direction normal to an arc along which the movable table 29 moves. An arm 33 extending in the Y-axis direction is attached to the upper portion of the column member 31.
A robot hand 35 for gripping the plate material W is provided at the tip of the so as to be swingable in the vertical direction and rotatable in the horizontal direction.

The mounting portion of the conventional robot hand 35 will be described with reference to FIGS. Referring to FIGS. 7 and 8, the tip of the arm 33 is branched into two forks 37L and 37R, and a robot hand 35 including an upper hand 39U and a lower hand 39L is provided between them.

Referring to FIG. 9 together, the fork 37L,
A mounting member 41 having a rectangular cross section is provided between 37R so as to be vertically swingable. A rotary shaft 43 having a cylindrical cross section having a vertical axis is rotatably provided inside the mounting member 41. The rotary shaft 43 is provided inside the rotary outer cylinder 45 and the rotary outer cylinder 45. It is composed of a rotating inner cylinder 47 which is vertically movable.

Referring also to FIG. 10, the rotating outer cylinder 45
Is a mounting member 4 by means of upper and lower bearing bearings 49, 49.
1 is rotatably inserted inside. This rotating outer cylinder 45
The bevel gear 5 on the driven side with the teeth facing downward near the center height of the
1 is integrally attached.

That is, as shown enlarged in FIG.
Conventionally, generally, the driven bevel gear 51 and the rotating outer cylinder 4 are
The wedge member 53 is pushed by the bolt 55 between 5 and the rotational force is transmitted by the frictional force so that the driven bevel gear 51 and the rotary outer cylinder 45 rotate integrally.

A rotary inner cylinder 47, which is vertically movable with respect to the rotary outer cylinder 45, is provided inside the rotary outer cylinder 45 and has a structure like a hydraulic cylinder. And
The guide hole 5 is provided at the upper end of the inner rotating cylinder 47 to move up and down along the guide pin 57 fixed to the upper end of the outer rotating cylinder 45.
9, the outer rotating cylinder 45 and the inner rotating cylinder 47 are provided.
Does not rotate relatively.

The lower hand 39L of the robot hand 35 is fixed to the rotating outer cylinder 45, and the upper hand 39U thereof is the rotating inner cylinder 47.
It is fixed to. Therefore, when a pressure fluid such as pressure oil is injected from a pressure source (not shown) through the pipe 61, the inner rotating cylinder 47 moves up and down as a piston using the outer rotating cylinder 45 as a cylinder, so that the upper hand 39U moves vertically. It moves to clamp the plate material W in cooperation with the lower hand 39L.

A fork 37L at the tip of the robot hand 35,
The 37R portion is provided with sprockets 67L and 67R that rotate by being connected to drive motors 63L and 63R provided in the arm 33 portion respectively by a chain 65, and one sprocket 67R is coupled to the mounting member 41. There is. Therefore, when the drive motor 63R rotates the sprocket 67R, the mounting member 41 swings up and down, so that the robot hand 35 swings.

A drive side bevel gear 69 that meshes with the driven side bevel gear 51 is integrally provided on the rotary shaft of the other sprocket 67L. Further, this rotating shaft has a double structure of a bearing bearing 71 and a bearing bearing 73, and the driven bevel gear 51 is rotated by the drive motor 63L rotating the sprocket 67L without being affected by the above-mentioned swing. The attached rotating outer cylinder 45 rotates. As a result, the robot hand 35 rotates with respect to the arm 33.

[0017]

As described above, conventionally, the driven-side bevel gear 51 for transmitting the rotational force to the robot hand 35 is rotated by the frictional force of the wedge member 53.
When the robot hand 35 is rotated integrally with the robot hand 35 and an excessive rotational force is applied to the robot hand 35, the wedge member 53 is loosened. This avoids a situation in which excessive force is transmitted to the robot 3 and the robot 3 is damaged.

However, in such a conventional technique, when the wedge member 53 is loosened, a rattling occurs in the meshing portion of the driving-side bevel gear 69 and the driven-side bevel gear 51, which causes trouble when restarting the gauging work. It will be. Further, when such backlash occurs, it is difficult for an operator to easily repair the work, and the work may not be continued.

The object of the present invention has been made by paying attention to the above-mentioned conventional techniques, and prevents the robot from being damaged when the robot hand is overloaded and easily repaired by an operator. Another object of the present invention is to provide a mechanism for transmitting a rotary shaft transmission mechanism of a robot hand that can restart the work.

[0020]

In order to achieve the above-mentioned object, a rotary shaft transmission mechanism mechanism of a robot hand according to the present invention is provided for a robot provided to supply a plate material to a plate material processing machine. A mechanism for transmitting a rotation axis of a robot hand, in which a robot hand holding a plate material is rotatably mounted in a horizontal direction at an arm tip, the mechanism being loosely fitted to a rotation shaft for rotatably supporting the robot hand and driven by a drive motor. A driven gear that meshes with a drive gear that transmits the rotational force of the ball, a ball that is integrally provided on the driven gear, and a recess into which the ball fits, and a ball that transmits the rotational force by the ball. A guide plate; and an elastic member that applies a pressing force to the ball to the ball guide plate and is fixed to the rotating shaft. Is shall.

[0021]

In the mechanism of the rotary shaft transmission mechanism of the robot hand according to the present invention, in order to supply the plate material to a predetermined position of the plate material processing machine, the robot hand for gripping the plate material is supported rotatably in the horizontal direction at the tip of the arm. ing. Transmission of the rotational force from the drive motor for rotating the robot hand is performed via the drive-side bevel gear and the driven-side bevel gear, but the driven-side bevel gear is not fixed to the rotating shaft and is not directly transmitted. That is, first, the balls protruding from the driven bevel gear are fitted into the recesses provided in the ball guide plate, so that the rotational force of the driven bevel gear is transmitted to the ball guide plate. The ball guide plate is fixed to an elastic member fixed to the rotating shaft so that the ball does not come out of the recess due to the repulsive force of the elastic member.
Therefore, the rotational force transmitted to the ball guide plate is transmitted to the rotating shaft via the elastic member. As a result, the robot hand fixed to the rotating shaft rotates. At this time, if an excessive rotational force acts on the robot hand, the ball will come out of the concave portion of the ball guide plate against the repulsive force of the elastic member, and it will be in a rotation-free state, so that it acts on the robot hand. Excessive rotational force is not transmitted to the arm.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the present invention will be described below with reference to the drawings. The same reference numerals are used for the parts already described in the section of the prior art, and the duplicated description will be omitted.

1 to 5 show a rotating shaft transmitting mechanism of a robot hand according to the present invention. As shown in FIG. 1, unlike the prior art, the driven-side bevel gear 75 is rotatably attached to the attachment member 41 by a bearing bearing 77, and one ball 79 is fixed to the upper end surface thereof.

A ball guide plate 81 is provided above the driven bevel gear 75 with the ball 79 interposed therebetween. Referring also to FIG. 5, the ball guide plate 81 has a circular ring shape, and one recess 83 into which the ball 79 is fitted is formed. Further, screw holes 85 are formed at two locations facing each other with the center in between, and two larger through holes 87 are provided.

On the upper side of the ball guide plate 81, there are provided leaf springs 89 as elastic members in the shape of a circular ring, like the ball guide plate 81, at regular intervals. Referring also to FIG. 4, this leaf spring 89 is provided with a screw mounting hole 91 corresponding to the screw hole 85 of the ball guide plate 81, and the ball guide plate 8 is attached by a bolt 93.
It is fixed at 1. Further, the leaf spring 89 is provided with two screw holes 95 and two through holes 97 at diagonal positions.

Further, on the upper side of the leaf spring 89, circular ring-shaped ring plates 99 are provided at regular intervals. Referring also to FIG. 3, the ring plate 99 has two mounting holes 103 for the bolts 101 for fixing the ring plate 99 itself to the upper portion 45U of the rotating outer cylinder 45, and the ring plate 99 with a fixed interval. Two screw holes 107 for the bolt 105 for fixing the leaf spring 89 are provided. Further, the through hole 10 is formed in the ring plate 99 so as not to interfere with the head of the bolt 93 that fixes the leaf spring 89 and the ball guide plate 81 at a constant interval.
Two 9 are provided. In addition, the upper part of the rotating outer cylinder
Is a ring-shaped lid in which the rotating inner cylinder 47 is loosely fitted,
The bolt 111 is integrally fixed to the rotating outer cylinder 45.

Therefore, the ring plate 99 is attached to the rotating outer cylinder 4
There is a through hole 97 in the leaf spring 89 to avoid interference with the head of the bolt 101 that is fixed to 5, and in order to avoid the interference between the leaf spring 89 and the head of the bolt 105 that fixes the ring plate 99. A through hole 87 is provided in the ball guide plate 81.

Since the ball guide plate 81, the plate spring 89 and the ring plate 95 are constructed as described above, they integrally move with respect to rotation. Therefore, the drive side bevel gear 6
The rotational force transmitted from 9 to the driven-side bevel gear 75 is transmitted to the ball guide plate 81 by the balls 79, to the plate spring 89 via the bolts 93, and further to the bolts 10.
Since it is transmitted to the ring plate 95 via 3 and finally transmitted to the rotating outer cylinder 45, the robot hand 35 can be rotated.

Further, since the leaf spring 89 bends in the vertical direction when a predetermined force or more acts, the ball 79 pushes up the ball guide plate 81 from the recess 83 when an excessive rotational force acts on the robot hand 35. When the driven bevel gear 75 is released, the rotational force from the driven bevel gear 75 is not transmitted to the rotating outer cylinder 45. Therefore, even if an excessive force acts on the robot hand 35, the damage is prevented from being transmitted to the arm 33 and the robot 3 main body.

When resuming the work from the above-mentioned rotation-free state, the worker simply rotates the robot hand 35 to align the concave portion 83 of the ball guide plate 81 with the position of the ball 79, and the repulsion of the leaf spring 89. By the force, the ball 79 is fitted into the recess 83 again and transmits the rotational force.
For this reason, the operator can easily repair and restart the next work.

The present invention is not limited to the above-described embodiments, but can be implemented in other modes by making appropriate modifications. That is, in the above-described embodiment, the bevel gears 69 and 75 are used, but the present invention is not limited to this, and can be applied to a combination of other gears having the same operation.

[0032]

The rotary shaft transmission mechanism of the robot hand according to the present invention is as described above. In order to supply the plate material to the predetermined position of the plate material processing machine, the robot hand holding the plate material is attached to the tip of the arm. It is rotatably supported in the horizontal direction. Transmission of the rotational force from the drive motor for rotating the robot hand is performed via the drive-side bevel gear and the driven-side bevel gear, but the driven-side bevel gear is not fixed to the rotating shaft and is not directly transmitted. That is, the balls protruding from the driven bevel gear are fitted into the recesses provided in the ball guide plate to transmit the rotational force of the driven bevel gear to the ball guide plate. The ball guide plate is fixed to an elastic member fixed to the rotating shaft so that the ball does not come out of the recess due to the repulsive force of the elastic member. Therefore, the rotational force transmitted to the ball guide plate is transmitted to the rotating shaft via the elastic member. As a result, the robot hand fixed to the rotating shaft rotates. At this time, if an excessive rotational force acts on the robot hand, the ball will come out of the concave portion of the ball guide plate against the repulsive force of the elastic member, and it will be in a rotation-free state, so that it acts on the robot hand. Excessive rotational force is not transmitted to the arm, and damage to the arm and robot can be prevented.

Further, when repairing from the state where the rotation is free, if the operator rotates the robot hand and aligns the ball of the driven bevel gear with the position of the recess of the ball guide plate, the ball is moved by the action of the elastic member. It fits into the recess and transmits the rotational force again. Therefore, it is very easy to repair and resume the work.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of a rotation shaft transmission mechanism reaching mechanism of a robot hand according to the present invention.

FIG. 2 is a plan view seen from the direction II in FIG.

FIG. 3 is a plan view showing details of a ball guide plate.

FIG. 4 is a plan view showing details of a leaf spring as an elastic member.

FIG. 5 is a plan view showing details of a ring plate.

FIG. 6 is a side view showing a press brake equipped with a work handling robot.

FIG. 7 is a bottom view of the robot hand as seen from below.

8 is a cross-sectional view as seen from the direction VIII-VIII in FIG. 7.

9 is a cross-sectional view as seen from the direction IX-IX in FIG.

FIG. 10 is a cross-sectional view showing a rotation shaft transmission mechanism reaching mechanism of a conventional robot hand.

11 is an enlarged view showing details of an XI portion in FIG.

[Explanation of symbols] 1 press brake (plate material processing machine) 3 robot 33 arm 35 robot hand 43 rotary shaft 63L, R drive motor 69 drive-side bevel gear (drive-side gear) 75 driven-side bevel gear (driven-side gear) 79 ball 81 ball Guide plate 83 Recessed portion 89 Leaf spring (elastic member) W Plate material

Claims (1)

[Claims] 1. A rotary shaft transmission mechanism for a robot hand, wherein a robot hand for holding a plate material is attached to the tip of an arm of a robot provided to supply the plate material to a plate material processing machine so as to be horizontally rotatable. A driven gear that is loosely fitted to a rotating shaft that rotatably supports the robot hand and that meshes with a driving gear that transmits a rotational force from a driving motor; and a ball that is integrally provided on the driven gear. A ball guide plate having a recess into which the ball fits and transmitting a rotational force by the ball; and an elastic member that applies a pressing force to the ball to the ball guide plate and is fixed to the rotating shaft. A rotation axis transmission mechanism for a robot hand, comprising: