JPH02160489A - Industrial robot of playback type - Google Patents

Abstract

PURPOSE:To reduce the degree of the breakdown and to re-open work immediately even if the arm tip is abutted to other device at manual operation time by providing a torque limit value changing over device reducing the output torque of a servo motor at manual operation time between a servo driving device and central arithmetic processing device. CONSTITUTION:When the changing over switch of an operation device is turned to 'manual' at teaching time, a changing over switch 30a of a torque limit value changing over device 30 is closed to change over from the adjusting resistor 27a for setting the internal part torque provided in a servo driving device 27 to the adjusting resistor 30b for setting the external part torque. Thus, the torque limit command value of the manual operation time is changed over and transmitted to the servo driving device 27, and the output torque of a servomotor 28 is reduced. As a result, the breakdown of the arm tip and the peripheral device is reduced even if the arm tip, etc., are brought into contact with the peripheral device at teaching time and work can immediately be reopened by an end effector exchange, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to an industrial robot, and particularly to a playback type industrial robot equipped with a protection function during manual operation.

(Conventional technology) Conventional playback type industrial robot (hereinafter referred to as

In Fig. 4, which shows a horizontal articulated robot (referred to as a robot), Fig. 4(a) shows a horizontal articulated robot, Fig. 4(b) shows a cylindrical coordinate robot,
The figure (c) shows a Cartesian coordinate robot, and the figure (d) shows a vertically articulated robot.

In the same figure (a), the first arm 1 is around the θ□ axis.

The second arm 2 is around the θ2 axis, and the third arm 3 is around the θ2 axis.

The third arm 3 rotates around the axis, and the third arm 3 rotates around the Z axis (vertical direction).
Operate in the direction.

In addition, in the same figure (b), the trunk 4 rotates around the axis θ, and the arm 5 moves in the Z axis (up and down direction) and the R axis (back and forth direction).
The wrist 6 rotates (θ2 axis) and bends (θ, axis).

Furthermore, in the same figure (c), the 17th beam 7 is in the X direction
The shaft holding portion 8 moves in the Y direction, the third arm 9 moves in the Z (up and down) direction, and one wrist 10 moves in the rotation (θ1) and bending (θ2) directions.

Similarly, in the same figure (d), the shoulder 11 is at θ, 411RI,
The first arm 12 is around the θ7 axis, and the second arm 13 is around the θ1 axis.
The third arm 14 performs θ around the axis, and the first wrist 15 performs bending (θ, ) 15 and rotation (θ6) movements around the axis.

FIG. 5 shows a control block diagram of a robot having such a configuration, in which the central processing unit 21 includes a storage device 22, a teaching device 23. A program input device 24, an operating device 25, an external storage device 26, and a servo drive device 27 that respectively drive each motion axis of the robot are connected.
A servo motor 28 with a rotation detector 29 is connected to the servo motor 28 .

Now, when a robot with such a control block diagram is to perform a work, a program created in advance must be stored in the storage device 22.

One position information of this program is the teaching device 23.
The sequence information is inputted through the program input device 24, and when playback is performed, it is taken out from the storage device 22 and commands are issued to the servo drive device 27.

As a protective function during manual operation or teaching operation of this robot, there is a function that constantly detects the robot's operating range and stops the robot when it leaves the pre-regulated working range. ■ Attach a limit switch to the robot's operating axis (for example, arm), and stop the robot using the signal from this switch.

■ Install a mechanical stopper on the robot's axis of motion to stop a robot that has run out of control.

Methods such as these are being used.

(Problem M to be solved by the invention) However, although such a protection function can prevent contact with peripheral devices that are outside the regulated range, it may prevent contact with peripheral devices that are within the regulated range at the time of teaching. collision is unavoidable.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a robot that can suppress damage to an arm, peripheral devices, etc. due to collision with peripheral devices due to runaway during manual operation such as teaching work.

[Structure of the invention]

(Means and effects for solving the problem) The present invention is characterized in that a servo motor is driven by a servo drive device provided for each of a plurality of motion axes, and a motion locus and motion are input in advance to a storage device via a teaching device. In playback type industrial robots that drive a servo motor through a servo drive device to perform playback operations based on commands from a central information processing unit, the output of the servo motor during manual operation is connected between the central information processing unit and the servo drive unit. By installing a torque limit switching device that reduces the torque, even if the operating axis comes into contact with other equipment during manual operation, the degree of damage can be reduced and the playback type industrial robot can resume work quickly. be.

(Embodiment) An embodiment of the playback type industrial robot of the present invention will be described below with reference to the drawings. However, parts that overlap with Fig. 5 are omitted.

FIG. 1 is a control block diagram of the playback type industrial robot of the present invention, in which the output side of a torque control value switching device 30 that changes the output torque limit value of each servo motor 28 is connected to the servo drive device 27. The input side of the torque limit value switching device 30 is connected to the output side of the central processing unit 21 . When the manual/automatic changeover switch (not shown) attached to the operating device 25 is manually operated for teaching work, for example, the torque limit value for automatic operation is 50 to 100% (however, the torque limit value is 300% for automatic operation). different).

FIG. 2 shows the torque limit value switching device 30. When the changeover switch (not shown) of the operating device is set to "manual", the torque changeover switch 30a is closed, and the internal torque setting switch provided in the servo drive device 27 is closed. The adjustment resistor 27a is switched to the external torque setting adjustment resistor 30b, and the torque limit command value during manual operation is switched and transmitted to the servo drive device 27.

As a result, even if the tip of the arm comes into contact with a peripheral device during teaching, the degree of damage to the tip of the arm or peripheral device can be suppressed, and it is possible to restart work after replacing the hand effector, for example. can.

FIG. 3 shows another embodiment of the torque limit value switching device for a robot according to the present invention.
A /A converter 31a is provided to change the automatic operation to manual operation, and the low limit value signal is transmitted to the servo drive device 27 via the D/A converter.

〔Effect of the invention〕

As described above, according to the present invention, a servo motor is driven by a servo drive device provided for each of a plurality of operating axes.

In a playback type industrial robot, the motion trajectory and program that have been input into the memory device in advance are replayed and operated based on commands from the central processing unit.

A torque limit value switching device is installed between the servo drive device and the central processing unit to reduce the output torque of the servo motor during manual operation, so even if the tip of the arm hits another device during manual operation, It is possible to obtain a playback type industrial robot that can reduce the degree of damage and can immediately resume work.

[Brief explanation of the drawing]

Fig. 1 is a control block diagram showing an embodiment of the playback type industrial robot of the present invention, Fig. 2 is a detailed view of the main part of Fig. 1, and Fig. 3 is a control block diagram showing an embodiment of the playback type industrial robot of the present invention. FIG. 4 is an external view showing the operation of a conventional playback type industrial robot, and FIG. 5 is a control block diagram of the conventional playback type industrial robot. 21...Central processing unit 22...Storage device 23...Teaching device 27
... Servo drive device 30 ... Torque limit value switching device (8733) Agent: Patent attorney Yoshiaki Inomata (and 1 others)
Figure 1 Figure 3 (c)

Claims (1)

[Scope of Claims] A servo motor is driven by a servo drive device provided for each of a plurality of operating axes, and the servo drive device uses a motion locus and a motion program that have been input in advance to a storage device based on instructions from a central information processing unit. In the playback type industrial robot that is operated for regeneration by driving the servo motor through A playback type industrial robot characterized by being equipped with a torque limiting switching device that reduces the torque.