JPH0411355B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an industrial robot used for loading workpieces onto machine tools, etc.

[Prior art]

In recent years, robots for loading and unloading workpieces into machine tools have been developed and put into practical use.

[Problem that the invention seeks to solve]

By the way, conventionally, for example, when mounting a workpiece onto the chuck of a lathe, the positioning accuracy of the robot is extremely high, so the workpiece can be mounted without detecting any interference (contact) between the workpiece and the chuck. It was on. However, in reality, the workpiece may have cutting burrs or rust from the previous process, and chips from the previous process may remain on the chuck, so it is not always possible to insert the workpiece into the chuck smoothly. In the end, this caused interference, and in the worst case, the robot arm could be damaged. Therefore, it is possible to detect interference between the workpiece and the machine tool (target device) and make an emergency stop of the robot, but there is a possibility that the workpiece and chuck will interfere when mounting or removing the workpiece on the chuck. This always occurs, and therefore, simply by detecting interference, it is not possible to determine whether or not it is necessary to actually bring the robot to an emergency stop.

This invention was made in consideration of the above circumstances, and its purpose is to create an industrial robot that can stop the robot hand only when an emergency stop is actually required in the event of interference between the workpiece and the target device. Our goal is to provide the following.

[Means to solve the problem]

In an industrial robot that performs a predetermined operation based on a work command instructed in advance, the present invention includes a detection means for detecting interference between a robot hand section and a target device, and a detecting means for detecting interference between the robot hand section and the target device. control means for disabling the detection means during work and enabling the detection means for work in which the robot hand section and the target device do not interfere; and a stopping means for stopping the robot hand section when the robot hand is detected. Here, the robot hand section refers to a portion consisting of a robot hand and a work gripped by the robot hand.

[Effect]

Whether or not the interference between the robot hand and the target device is abnormal is determined based on whether the robot hand and the target device are working in an interference state or not. can do. Therefore, according to the above configuration, it is possible to stop the robot hand section only when the interference is in an abnormal state.

〔Example〕

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention. In this figure, numeral 1 is a lathe (target device), and 2 is a chuck of the lathe 1. 3 is a robot mechanism, which includes a base 3a, an arm 3b,
The hand 3d is connected to the tip of the arm 3b via an insulating joint 3c. 4 is a work gripped by the hand 3d, and 5 is a robot control device. In this robot control device 5, 6 and 7 are terminals, and the terminal 6 is connected to the hand 3d.
The terminals 7 are each connected to the lathe 1, and the terminals 7 are grounded inside the control device 5.
Reference numeral 8 denotes an interference detection circuit, which is composed of a relay 9, inverters 10 and 11, and a NAND gate 12. This interference detection circuit 8 is a circuit that detects interference (contact) between the lathe 1 and the workpiece 4,
When there is no interference between the two, the relay 9 is not excited, the contact 9a is open, and the output of the inverter 10 is at the "L" level. As a result, the output of the NAND gate 12 becomes "H" level, and the interrupt signal IR from the inverter 11 goes "L".
level signal to the microprocessor unit 14.
supplied to On the other hand, when lathe 1 and workpiece 4 interfere, relay 9 is excited, contact 9a is turned on, and the output of inverter 10 becomes "H" level. In this case, the interference detection permission signal G output from the microprocessor unit 14 is “H”.
When the level is high, the interrupt signal IR becomes "H" level, and an interrupt is applied to the microprocessor unit 14. On the other hand, when the signal G is at the "L" level, the interrupt signal IR is at the "L" level, and the microprocessor unit 14 is not interrupted.

Next, the microprocessor unit 14 reads the program stored in the memory 15, and
A robot control signal is created based on the read program and output to the robot control circuit 16. The robot control circuit 16 drives the robot mechanism 3 based on this control signal. In addition, this microprocessor unit 14
generates an interference detection permission signal G based on the program and outputs it to the NAND gate 12. moreover,
When the interrupt signal IR (“H” level) is supplied,
The interrupt processing program is read from the memory 15, and based on this program, the alarm device 17 is driven and a stop signal is output to the robot control circuit 16. Robot control circuit 16
receives this stop signal and stops the operation of the robot mechanism 3.

Next, a specific example of the processing of this microprocessor unit 14 will be explained with reference to FIG. Note that FIG. 2 is a diagram showing an example of a program in the memory 15. First, the interference detection permission signal G is set to the "H" level (step S1 in FIG. 2), and then the hand 3d is moved to the vicinity of the workpiece placement position (step S2). Next, the signal G is set to the "L" level (step S3), and then the hand 3d is moved to the work position. Next, the hand 3d is closed and the workpiece 4 is gripped (step S5). Next, move hand 3d slightly (step
S6), then the signal G is set to "H" level (step S7), and from then on, the hand 3d is moved according to the predetermined route.
Move to chuck 2 position. Next, the work 4 is inserted into the chuck (step S8), the signal G is set to "L" level (step S9), and the work 4 is moved to the mounting position (step S10). Next, the chuck 2 is closed (step S11), and then the hand 3d is opened (step S12). At this point, the attachment of the workpiece 4 to the chuck 2 is completed. Next, the signal G is set to the "H" level (step S13), and then the hand 3d is returned to its original position (step S14).

As described above, in the embodiment shown in FIG. 1, the signal G is set to the "H" level when the workpiece 4 is inserted into the chuck 2. As a result, if interference occurs between workpiece 4 and chuck 2,
An interrupt signal IR (“H” level) is generated, and the above-described interrupt processing is performed. On the other hand, immediately before the chuck 2 grips the workpiece 4, the signal G is set to the "L" level. As a result, even if interference occurs when workpiece 4 is gripped by chuck 2, an interrupt signal is generated.
No IR will occur.

Note that the functions of the NAND gate 12 shown in FIG. 1 may be performed by a program.

〔Effect of the invention〕

As described above, according to the present invention, when there is interference between the robot hand and the target device, it is possible to perform an emergency stop only when the robot hand does not interfere with the target device.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention, and FIG. 2 is a diagram showing an example of a program stored in the memory 15 in FIG. 1... Lathe (target device), 3d... Robot hand, 4... Workpiece, 8... Interference detection circuit, 14
...Microprocessor unit, 15...Memory.

Claims (1)

[Claims] 1. In an industrial robot that performs a predetermined operation based on a pre-instructed work command, a detection means for detecting interference between a robot hand section and a target device;
control means for disabling the detection means during work in which the robot hand section and the target device interfere, and enabling the detection means during work in which the robot hand section and the target apparatus do not interfere; An industrial robot characterized by comprising: a stopping means for stopping the operation of the robot hand section when the detecting means detects interference when enabled.