JP2002283263A - Interval adjusting method of work gripping part - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technology capable of omitting an actuator by skillfully using capacity of a robot hand. SOLUTION: A moving means 17 with a brake is put in an unrestricted state in a drawing (c). The robot hand 11 is moved to change an interval between first and second gripping parts 13 and 16 to a required interval L1. The brake is applied. At this time, since the second gripping part 16 contacts with a dummy bore 31, the robot hand 11 is moved rightward a little in the drawing (for example, by Δ1) for eliminating this contact. Then, the first and second gripping parts 13 and 16 are moved to a standby position. Thus, since the interval between the first and second gripping parts 13 and 16 is adjusted by a robot, there is no need to arrange the expensive and complicated actuator in a work gripping mechanism so that the work gripping mechanism can be formed as an inexpensive and simple structure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a method for adjusting a distance between workpiece grips.

[0002]

2. Description of the Related Art For example, Japanese Unexamined Patent Publication No. Hei 7-132481, entitled "Robot Hand Finger Width Variable Mechanism", uses a robot arm 5 (the reference numeral used in the publication is used) as shown in FIG. Fork-shaped guide 2 at the tip
And a pair of left and right fingers 1, 1
Is mounted so as to be able to move laterally, and a screw shaft called a movable mechanism 3 is screwed to these fingers 1, 1 and this screw shaft is turned clockwise or counterclockwise by an actuator 4 to freely set the distance between the fingers 1, 1. It can be adjusted.

[0003]

The above mechanism requires a high-grade actuator 4 which is provided separately from the robot hand 5 and has a control function of counting the number of rotations, which increases the cost as a whole. An object of the present invention is to provide a technique capable of eliminating expensive actuators by skillfully utilizing the capabilities of a robot hand.

[0004]

In order to achieve the above object, a first aspect of the present invention is to provide a robot hand having a pair of diametrically expandable and contractible gripping portions at a tip thereof, wherein the gripping portions correspond to a workpiece to be gripped. A method for adjusting the distance between workpiece gripping portions for transporting a workpiece by means of a workpiece gripping mechanism comprising: means for freely expanding and contracting the interval between a pair of gripping portions; and means for fixing the interval between the pair of gripping portions. Using, after fixing one gripping part of the pair of gripping parts at a predetermined position, after moving the tip of the robot hand to adjust the interval with the other gripping part,
The interval is fixed.

After fixing one of the pair of grippers at a predetermined position, the distal end of the robot hand is moved to adjust the gap with the other gripper, and then the gap is fixed.
That is, since the interval adjustment is performed by the robot, it is not necessary to provide an expensive and complicated actuator for the work gripping mechanism, and the work gripping mechanism can have a simple structure at low cost.

[0006]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a diagram showing the principle of a work gripping mechanism according to the present invention. A work gripping mechanism 10 has a common plate 12 attached to the tip of a robot hand 11.
2, a first gripper 13 is fixedly mounted on the common plate 12, a second gripper 16 is movably mounted on the common plate 12 via a rail 14 and a slider 15, and a brake for moving the slider 15 supporting the second gripper 16. Moving means 17 with common plate 12
It is a component attached to.

The first grip 13 comprises a bracket 18 and a balloon 19 provided at the tip of the bracket 18. Although the balloon 19 is deflated in the figure, it can be inflated by gas pressure as shown by an imaginary line. It is a part that can be enlarged. The second grip 16 also includes a bracket 21 and a balloon 22 provided at the tip of the bracket 21. That is, by making the bracket 18 longer and the bracket 21 shorter, the levels of the balloon 19 and the balloon 22 are made uniform.

The moving means with brake 17 is preferably an air cylinder. If it is an air cylinder, a gas is supplied from the port a, and if the port b is opened to the atmosphere, a piston is provided at the stroke end on the retreating side as shown in the figure. 23 can be positioned. Here, if both the a port and the b port are closed, the piston 23 cannot move,
The brakes are applied.

That is, of the functions of the moving means 17 with a brake, the moving means portion corresponds to "means for making the interval between the pair of grip portions freely expandable and contractable", and the brake portion "fixes the interval between the pair of grip portions." Means ".

[0010] Alternatively, if both the a port and the b port are open to the atmosphere, the piston 23 becomes movable and unconstrained, and the second gripping portion 16 indicated by a solid line by an external force.
Can be moved to the position indicated by the imaginary line. Of course, the moving means with brake 17 may be provided with an independent external brake, which creates a simple moving action, a simple positioning action to determine one point, a braked state and an unconstrained state. Any means can be used, as long as it can be used.

A cylinder block 25 shown at the bottom of the figure is a specific example of a work.
It is an in-line four-cylinder cylinder block including a plurality of cylinder bores 26 to 29. The bore pitch L1 between the first cylinder bore 26 and the fourth cylinder bore 29 is the required interval for this work.

The upper right part of the cylinder block 25 is a dummy bore 31 serving as a substitute for a work.
A cylinder 32 having an inner diameter equivalent to the diameter of a bore of a work is provided by a bracket 33 at an appropriate position in a robot turning area.

The robot hand 11 performs position control and the like with a robot control unit 34 provided as standard equipment on the robot. By inputting L1 information (request interval information) to the robot control unit 34, The described control is also executed.

The operation of the work holding mechanism 10 described above will be described with reference to FIGS. FIGS. 2A to 2C are first operation explanatory diagrams of the work gripping mechanism according to the present invention. In (a), the second gripper 16 is moved by the arrow using the moving means with brake 17 provided on the robot hand 11, and
-Change the interval between the second gripping portions 13 and 16 to the predetermined interval L0 and apply the brake. This brake is a measure for preventing the second grip 16 from moving due to vibration or the like when the second grip 16 is moved as shown by the arrow.

In FIG. 2B, the robot hand 11 is moved, and the second grip 16 is inserted into the dummy bore 31 serving as a substitute for the work. This step can be performed even if the dummy bore 31 is replaced with a cylinder block or a suitable stopper. Here, the gap between the dummy bore 31 and the second grip 16 is defined as Δ1.

In (c), moving means with brake 1
7 is put in an unrestrained state. Then, the robot hand 11 is moved by the difference (L1 + Δ1−L0) under the control of the robot control unit (reference numeral 34 in FIG. 1) to change the interval between the first and second gripping units 13 and 16 to the required interval L1. And
Apply brakes. At this time, since the second gripper 16 is in contact with the dummy bore 31, the robot hand 11 is slightly moved (for example, Δ1) to the right in the figure to eliminate the contact. Then, the first and second grippers 13 and 16 are moved to the standby positions.

FIGS. 3A and 3B are views for explaining a second operation of the work gripping mechanism according to the present invention. In (a), the workpiece is gripped and moved in the following manner using the workpiece gripping mechanism 10 at the standby position. First, by moving the robot hand 11, the balloon 22 is inserted into the first cylinder bore 26 as indicated by an arrow, and the balloon 22 is inserted into the fourth cylinder bore 29. And balloon 1
9. Inflate 9, 22 with gas pressure. In (b), the first
The cylinder block 25 is moved from the first workbench 36 to the second workbench 37 while being suspended by the second grippers 13 and 16. After that, it is sufficient to return to FIG.

FIG. 4 is a diagram showing another embodiment of the work gripping mechanism according to the present invention. The work gripping mechanism 10B has a common plate 12 attached to the tip of a robot hand 11,
2, the first grip 13 and the second grip 16 are attached to the rail 1
4L, 14R and sliders 15L, 15R, each of which is mounted so as to be horizontally movable, and a moving means with brake 17B for moving the slider 15R which supports the second grip portion 16.
Is attached to the common plate 12 and a pair of sliders 15
L, 15R, arms 41L, 41 facing each other
R is extended, and a rack 42 is attached to these arms 41L and 41R.
L, 42R are carved, and a pinion 43 is bitten by these racks 42L, 42R, and this pinion 43 is rotatably attached to, for example, the moving means 17B with a brake. The first grip 13 and the second grip 16 are composed of a bracket 18 and a balloon 19. Therefore, the first grip 13 and the second grip 16 are the same.

When the piston rod of the moving means with brake 17B is moved forward or backward, the right arm 41R moves right or left, and the pinion 43 is turned by this moving amount to move the left arm 41L left or right. To the same amount. The distance between the first grip 13 and the second grip 16 is L1
When the piston of the moving means with brake 17B is retracted by (L1-L0) / 2, the first gripper 1
3 can be returned to L0 (predetermined interval).

That is, the interval can be changed by twice the moving amount of the piston of the moving means with brake 17B. As a result, the length of the moving means with brake 17B can be reduced to half. In addition, if the moving speed does not change, the interval can be adjusted in half the time.

As described above, both the first gripper 13 and the second gripper 16 can be moved laterally.
The object of the present invention can be achieved by making only one of the grip 13 and the second grip 16 laterally movable.

In the embodiment, the predetermined distance L0 is smaller than L1. However, L0 may be larger than L1. In other words, the predetermined distance L0 can be repeatedly and continuously produced by the moving means with a brake. A constant value may be used.

[0023]

According to the present invention, the following effects are exhibited by the above configuration. In the first aspect, one of the pair of gripping portions is fixed at a predetermined position, and then the tip of the robot hand is moved to adjust the interval with the other gripping portion, and then the interval is fixed. That is, since the interval adjustment is performed by the robot, it is not necessary to provide an expensive and complicated actuator for the work gripping mechanism, and the work gripping mechanism can have a simple structure at low cost.

[Brief description of the drawings]

FIG. 1 is a principle diagram of a work holding mechanism according to the present invention.

FIG. 2 is an explanatory view of a first operation of the work holding mechanism according to the present invention.

FIG. 3 is a diagram illustrating a second operation of the workpiece gripping mechanism according to the present invention.

FIG. 4 is a diagram showing another embodiment of the work holding mechanism according to the present invention.

[Explanation of symbols]

10, 10B: Work gripping mechanism, 11: Robot hand, 13: First gripping part, 15, 15L, 15R: Slider, 16: Second gripping part, 17, 17B: Moving means with brake, 19, 22: Balloon, 25: Cylinder block as a work, 31: Dummy bore as a substitute for a work, 34: Robot control unit, L0: predetermined distance, L
1 ... required distance, (L1-L0) ... difference.

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) 3C007 AS01 DS02 DS10 ES13 EV14 HS11 NS11

Claims (1)

[Claims] 1. A method for adjusting a distance between work gripping portions for transporting a workpiece to be provided with a pair of gripping portions capable of expanding and contracting in a radial direction at a tip end of a robot hand, wherein the gripping portion corresponds to a workpiece to be gripped. A work gripping mechanism comprising: means for expanding and contracting the interval between the pair of gripping portions; and means for fixing the interval between the pair of gripping portions, wherein one of the pair of gripping portions is used. A method of adjusting the distance between the workpiece gripping portions, wherein the gripping portion is fixed at a predetermined position, the tip of the robot hand is moved to adjust the interval with the other gripping portion, and then the interval is fixed. .