JPS62228388A - Hand for robot - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a robot hand for an industrial robot in which the opening degree of the hand is set to the minimum necessary size relative to the size of an object to be gripped.

Conventional technology In general, robot hands are made to have a considerable opening in advance so that they can grip a wide range of workpieces, from small diameter ones to large diameter ones. It is necessary to open the workpiece to the full opening degree, and when gripping the workpiece, the hand always closes from the open state to grip the workpiece.

Problems to be Solved by the Invention For this reason, when arranging workpieces on the bullet, the workpieces must be spaced widely apart so that even small-diameter workpieces do not interfere with the hand that is opened to a certain maximum opening. i
It was not possible to increase the number of ffs even when the diameter was small. In addition, by reducing the workpiece spacing, a large number of
If you try to place the workpiece on top of the workpiece, the opening degree of the hand will be restricted and you will not be able to grip a wide range of workpieces. Therefore, there are inconveniences in that it is difficult to automate high-mix, low-volume production, and it is not possible to efficiently use an increased number of pallets.

Means for Solving the Problems A transmitting section 11 and a receiving section 12 of a non-contact detector using radio waves, ultrasonic waves or light waves are provided on the side surface of the gripping section of the robot hand 1 on the workpiece side. While the receiving section 12 is detecting the reflection of the output from the workpiece, the receiving section 1 acts in the direction of opening the grip opening/closing device 7 of the robot hand.
A control means 14.10 is provided for stopping the opening operation of the robot hand 1 and maintaining the opening degree when the robot hand 2 no longer detects the reflection or when the reflex human power becomes weak, and the robot hand is kept in the closed state. The signal is transmitted at a predetermined position on the gripped workpiece to open the gripping portion of the robot hand to an opening degree suitable for gripping the workpiece.

Example Embodiments of the present invention will be described below based on the drawings.

The robot hand 1 is a well-known device whose movement, rotation, etc. are controlled by NC or the like, and the hand portion 2 includes, for example, gripping surfaces 3a, 3b.
The grippers 4a and 4b are guided and supported within the hand portion 2 so as to be able to move in parallel so that they can approach and separate from each other,
A rack 5 of the same pitch is provided on the opposite surface of each guide part.
A and 5b are engraved. A binion 6 is rotatably supported in the center between the racks 5a and 5b, and the tanks 5a and 5b are positioned 180° opposite to the binion 6.
are intertwined with each other. Gripper 4 inside hand part 2
A fluid pressure cylinder device W7 is attached parallel to the moving direction of the pistons a and 4b, and the piston loft 9 of the piston 8 is
is connected to the gripper 4a. This fluid pressure cylinder device 7 has its front chamber Ta.

The rear chambers 7b are each connected to the pressure source side P and the tank side T by a 3-position 4-port electromagnetic switching valve IO having a neutral position. Further, a transmitting element 11 which is a special feature of the present invention
．． The receiving element 12 is attached to the side surface of the gripping surface 3a of the gripper 4a on the workpiece W side on the pallet, almost symmetrically around the center of the first surface, near the end, with the transmitting surface and the receiving surface facing toward the workpiece W side of the pallet, respectively. The robot hand 1 is positioned at an angle such that when the robot hand 1 is located within a certain height range above the workpiece on the pallet, the waves emitted from the transmitting element 11 are reflected by the surface of the workpiece W and are incident on the receiving element. installed.

The transmitting element 11 and receiving element 12 are gripped by 7 surfaces 3a and 3b.
It is also possible to provide each. Transmission element 11. The receiving element 12 is a known radio wave.

A device that transmits and receives ultrasonic waves, light beams, etc., or a device equivalent thereto is used.

The transmitting element 11 is connected to a transmitter 13 by a lead wire (or optical cable), and the transmitter 13 is connected to the robot hand l.
When it is positioned at a predetermined position on the pallet by control of NC or the like, it is activated by the positioning signal. The receiving element 12 is connected to the receiver 1 by a lead wire (or optical cable).
4, and the detection signal activates the relay of the receiver 14, which operates only when the signal is manually operated, and the 5Q of the electromagnetic switching valve 10 operates.
L1 is actuated and switched to the ■ position to send pressure fluid to the rear chamber 7b of the cylinder 7 and open the grippers 4a and 4b. Although not shown, the control circuit operates 5QL2 in response to a workpiece gripping command, sets the electromagnetic switching valve 0 to the m position, and sends pressure fluid to the front chamber 7a of the cylinder, and the gripper 4a receives a command between the workpieces to release the workpiece grip.

A control circuit is provided that operates SQL 1 in response to an NC command to open 4b.

The grippers 4a and 4b of the working robot hand 1 are placed on a pallet (not shown) with the electromagnetic switching valve 10 located at the m position and pressurized fluid being sent to the front chamber 7a of the fluid pressure cylinder 7 to close the grippers 4a and 4b. When a command to grasp the workpiece is issued,
The robot hand 1 grips the workpiece on the pallet at a predetermined height using a control device such as an NC, and transmits the transmitting element 11 on the 7th surface 4a.
Then, the transmitter 13 is activated by this positioning completion signal, emitting ultrasonic waves from the transmitting element 11, and the reflected waves from the end face of the workpiece W are transmitted to the receiving element. 12 will receive it.

While the input is being input to the receiving element 12, the relay of the receiver 14 is turned on, and 5OLI of the electromagnetic switching valve 10 is turned on and held at 1 position, and the pressure fluid is sent to the rear chamber 7b of the fluid pressure cylinder 7, and the piston 8 Move forward and continue to open both grips, pa 4a and 4b. The gripper opens and the transmitting element 11. Receiving element 12
move in the radial direction of the workpiece W at the same time and the ultrasonic waves are removed from the workpiece W, the reflected light reflected from the pallet surface is shifted and does not enter the receiving element, so the relay of the receiver 14 is turned off, and the electromagnetic switching valve 10 SQL 1 is also turned off and switched to the neutral state ■ position, grippers 3a and 3b
maintains its opening at that position. At this opening degree, the transmitting element 11. Since the receiving element 12 is attached to the edge of the V surface, the tangent line connecting the pixel elements becomes the detection line as shown in FIG.
No interference occurs between 'b and the workpiece. By turning off the relay of the receiver 14, the control device of the robot hand 1 acts,
Lower the hand and use a control circuit not shown? it magnetic switching valve 1
Operate S○■ and 2 of 0 to open the front chamber 7 of the pressure fluid cylinder 7.
A is used to grip the feed workpiece.

In addition, as a countermeasure for the case where the direction of the reflected wave shifts due to a slight inclination of the end face of the workpiece, the beam diameter is increased and the receiving element 1
2. Further, when the reflected beam from the bullet is incident, a circuit is added that determines that there is no workpiece if the incident beam does not exceed a certain level. Furthermore, for safety when no output is output from the transmitting element 11, if necessary, a touch sensor, a non-contact detector, etc. may be provided on the gripping surface 3b of the other gripper 4b, and when a detection output is output from this, the robot hand can be immediately This is to stop the descent.

Effects As detailed above, the present invention provides a transmitting element and a receiving element on the side of the workpiece to be gripped by the robot hand, and transmits the signal at a predetermined height above the workpiece, so that the gripper, which is closed, gradually closes while there is a received signal. Since the gripper stops opening when the gripper is opened and reception is no longer received, the hand can be positioned at the gripping position of the workpiece with the minimum necessary opening.
The distance between adjacent workpieces is only a small gap in addition to the thickness of the gripper and gripping V surface, allowing multiple workpieces to be placed side by side, allowing efficient use of pallets and contributing to the automation of high-mix, low-volume production. It is something.

[Brief explanation of drawings]

FIG. 1 is a detailed explanatory diagram of the present invention, and FIG. 2 is a diagram showing detection lines. Figure JJ3 is a control diagram of the gripper, and Figure 4 is a diagram of the arrangement on a conventional bullet.

Claims (4)

[Claims] (1) A transmitting part and a receiving part of a non-contact detector using radio waves, ultrasonic waves, or light waves are provided on the side surface of the gripping part of the robot hand on the workpiece side, and the reflection of the output of the transmitting part by the workpiece is received. While the receiving section is detecting, the opening/closing device of the robot hand is actuated in the opening direction, and when the receiving section no longer detects reflection or the reflected input becomes weak, the opening operation of the robot hand is stopped. The robot hand is provided with a control means for maintaining the opening degree, and when the robot hand is in a closed state, a signal is transmitted at a predetermined position on the gripped workpiece to open the gripping part of the robot hand to an opening degree suitable for gripping the workpiece. robot hand. (2) The robot hand according to claim 1, wherein the non-contact detector is an ultrasonic transmitting and receiving device. (3) The robot hand according to claim 1, wherein the non-contact detector is a light beam emitting/receiving device. (4) The robot hand according to claim 1, wherein the receiving section has a function that does not operate below a certain input level.