JPH10249760A - Industrial robot - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an industrial robot in a smaller and simpler structure with more reliability in operation. SOLUTION: For a robot 21, a motor 23 is fixed to a base 22 and a pulley 25 is provided at an output shaft 24 of the motor 23. A ball screw 27 is fixed to the base 22 in parallel to the output shaft 24 of the motor 23. The ball screw 27 is stored in a housing 28, with one end fixed to a pulley 29 and the other end rotatably supported by the housing 28. A timing belt 30 is arranged between the pulleys 25, 29 for power transmission. In an area, where the ball screw 27 is protruded from the housing 28, a braking device 32 as an excitation open type braking device, which is excited by a controller 31 formed with a microcomputer, e.g. to turn off a brake when a current flows and to turn on the brake when a current is cut, and an encoder 26, which is a rotation detector to detect the rotating speed of the motor 23, are integrally provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to, for example, an industrial robot that performs a linear motion.

[0002]

2. Description of the Related Art FIG. 4 is a perspective view of a conventional industrial robot (hereinafter, a robot) 1. In the robot 1, a motor 3 is fixed to a base 2, a pulley 5 is provided on an output shaft 4 of the motor 3, and the rotation speed of the motor 3 is detected by an encoder 6. On the other hand, a ball screw 7 is fixed to the base 2 in parallel with the output shaft 4 of the motor 3. The ball screw 7 is housed in a housing 8 and has a pulley 9 at one end.
Is fixed, and the other end of the ball screw 7 is rotatably supported by the housing 8. A timing belt 10 for transmitting power is provided between the pulleys 5 and 9. In the vicinity of the other end of the ball screw 7, for example, an excitation-release type brake 12 is provided, which is excited when energized by a control device 11 composed of a microcomputer or the like, turns off the brake, and turns on when the power is cut off. ing.
The motor 3 and the encoder 6 are connected to the control device 11. The control device 11 controls the motor 3 by the encoder 6.
The control device 13 rotates the motor 3 at a predetermined rotation speed according to a separately input instruction speed signal. The ball screw 6 has a slider 13
Is provided. The slider 13 linearly moves bidirectionally along the axial direction of the ball screw 7 with the bidirectional rotation of the ball screw 7 by the motor 3. The slider 1
3 is provided with various operation mechanisms such as a hand, and is used as the industrial robot 1. At this time, the cover 14 is attached to the pulleys 5 and 9 and the timing belt 10.

[0003]

In the prior art industrial robot 1, the encoder 6 and the brake 12
Is different from each other and is configured as a separate component. Therefore, it is necessary to separately provide a wiring board on which a control element is mounted, so that the number of components of the robot 1 increases and the configuration increases in size. There is a problem.

Further, in the conventional industrial robot 1, the timing belt 10 is made of synthetic rubber or the like, and may be broken during use due to deterioration of material or fatigue. At this time, as described above, since the cover 14 is attached to the pulleys 5 and 9 and the timing belt 10, the breakage of the timing belt 10 cannot be detected visually. Timing belt 1
When 0 is broken, the rotation of the motor 3 is not transmitted to the ball screw 7, so that the ball screw 7 stops rotating. However, since the mechanism for detecting this is not provided, it is also possible to detect the break of the timing belt 10. Can not. Also,
In order to detect the breakage of the timing belt 10, another conventional technique in which a sensor such as a photo interrupter is installed in the vicinity of the timing belt 10 is conceivable, but in this case, the number of components such as sensors increases. Occurs. That is, in the robot 1 of the related art, the breakage of the timing belt 10 cannot be detected visually or visually by an operator, and the operation reliability of the robot 1 is low. is there. Further, in such a case, an operation abnormality is caused in the entire production system as an example including the robot 1, and there is also a problem in that the operation reliability of the robot 1 is low.

An object of the present invention is to solve the above-mentioned technical problems, and to provide an industrial robot whose configuration is reduced in size and simplified and whose operational reliability is remarkably improved.

[0006]

In the industrial robot according to the first aspect of the present invention, the rotation of the motor is transmitted to the rotating shaft by a transmitting member, and the rotating shaft is rotated. The slider is driven to travel along with the rotation of the rotating shaft. At this time, a rotating member is fixed to the rotating shaft, and the rotation of the rotating member is released or braked by energizing or de-energizing the braking element. Further, a rotation detection unit is provided near the rotation member of the rotation shaft, and the rotation detection unit rotates with the rotation of the rotation shaft. A rotation detecting element is provided in the vicinity of the rotation detection part, and the rotation of the rotation detection part is detected by the rotation detection element.

[0007] Thus, the braking device and the rotation detecting device can be installed at positions close to each other on the rotating shaft and can be integrally configured. Therefore, it is possible to use a common wiring board or the like on which elements used for these controls are mounted, and it is possible to reduce the size and simplify the overall configuration of the robot.

Further, it is easy to compare a signal relating to the number of revolutions of the rotating shaft detected by the rotation detecting device with a signal for rotating the motor for driving the rotating shaft at a predetermined number of revolutions. Even when the vicinity of the transmission member cannot be visually confirmed from the outside, the breakage of the transmission member can be detected. In addition, this can prevent a situation in which an operation abnormality of the entire system including the industrial robot occurs, and can significantly improve operational reliability.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view of a robot 21 according to one embodiment of the present invention, FIG. 2 is a cross-sectional view of the lower part of the robot 1, and FIG. 3 is a flowchart showing the operation of the present embodiment.

In the robot 21, a motor 23 is fixed to a base 22, and a pulley 25 is provided on an output shaft 24 of the motor 23. A ball screw 27 serving as a rotation axis is fixed to the base 22 in parallel with the output shaft 24 of the motor 23. The ball screw 27 is housed in a housing 28, a pulley 29 is fixed to one end of the ball screw 27, and the other end of the ball screw 27 is rotatably supported by the housing 28. The pulley 2
A timing belt 30 for power transmission is provided between 5 and 29. The housing 28 of the ball screw 27
The portion protruding from the brake device 32 is an excitation-release type braking device, for example, which is energized by a control device 31 including a microcomputer or the like when energized to turn off the brake and is turned on when the energization is cut off,
An encoder 26 which is a rotation detection device for detecting the rotation speed of the motor 23 is provided integrally.

Hereinafter, the brake device 32 and the encoder 26
The details of the configuration will be described. A portion of the ball screw 27 near the bottom 35 of the housing 28 is rotatably supported by the bearing 36 with respect to the housing 28. Ball screw 2
A detection disk 38, which is a detection target for the encoder 26, is fixed to an end of the mounting shaft 37, which is a portion further protruding from the bottom 35 of the housing 28 and has no external thread formed thereon, for detection. A sensor 39 such as a photo interrupter is arranged near the disk 38 as an example. The sensor 39 is a wiring board 40 on which circuit elements for driving the sensor 39 are mounted.
And the other wiring board 41 is fixed to the bottom 35 of the housing 28 with bolts 42. The detection disk 38 and the sensor 39 constitute the encoder 26.

An armature 43 whose circumferential displacement is prevented by the bolt 42 is provided between the encoder 26 and the bottom 35. Armature 43
A support disk 44 fixed coaxially to the mounting shaft portion 37 and a disk 45 made of a ferromagnetic material and the like fixed to the outer periphery of the support disk 44 are arranged inside. A coil 46 is housed in a housing 47 in the vicinity of the disk 45, and a brake spring 49 whose spring pressure can be adjusted by an adjusting bolt 48 is provided between the bottom 35 and the armature 43.

The armature 43 is magnetically attracted, for example, by the action of a magnetic field generated from the coil 46 when the coil 46 is energized, is separated from the disk 45, the disk 45 is freely rotated, and the ball screw 27 is free. It is ready to rotate. On the other hand, when the power supply to the coil 46 is cut off, the magnetic coupling between the coil 46 and the armature 43 is released, and the armature 43 is pressed against the disk 45 by the spring force of the brake spring 49, and the rotation of the ball screw 27 causes braking. Added.

A motor 23 and an encoder 26 are connected to the control device 31. The control device 31 is an encoder 2
6, a speed signal corresponding to the rotation speed of the motor 23 by the motor 6 is detected, and the control device 3
1 rotates the motor 23 at a predetermined rotation speed. A slider 33 is provided on the ball screw 26. Slider 3
3 moves linearly bidirectionally along the axial direction of the ball screw 27 with the bidirectional rotation of the ball screw 27 by the motor 23. Various operation mechanisms such as a hand are attached to the slider 33 and used as the robot 21. At this time, a cover 34 is attached to the pulleys 25 and 29 and the timing belt 30. The brake device 32 is provided to prevent problems such as the slider 33 dropping by its own weight and colliding with the housing 28 when the robot 21 stops.

The operation of this embodiment will be described below with reference to FIG. In step a1, as described above,
The control device 31 rotates the motor 23 at a predetermined rotation speed. During this rotation control, a rotation speed signal from the encoder 26 is periodically taken in at step a2. Step a3
Thus, the control device 31 controls the motor 2 that is determined from the rotation speed signal.
3 and the motor 2 determined from the indicated speed signal
Then, it is compared with the rotation speed of No. 3 to determine whether they match. If they match, it means that no trouble such as breakage of the timing belt 30 has occurred, and the process returns to step a1 to repeat the above process.

On the other hand, if the determination is negative in step a3, the controller 31 determines in step a4 that the timing belt 30 has been broken, and in step a5, the motor 23
The processing for stopping is performed. Further, if a notification device such as a lamp or a buzzer for notifying an abnormal state is provided to the outside of the robot 21, the abnormality notification operation may be performed following the process of stopping the motor 23.

As described above, in the robot 21 according to the present embodiment, the brake device 32 and the encoder 26 are installed at positions close to each other on the mounting shaft portion 37 which is a part of the ball screw 27, and are integrally configured. be able to. Therefore, the wiring boards 40 and 41 on which elements used for controlling the brake device 32 and the encoder 26 are mounted can be shared, and the overall configuration of the robot 21 can be reduced in size and simplified. it can.

Further, in the robot 21 of this embodiment,
The timing belt 30 is made of synthetic rubber or the like, and may break during use due to deterioration of the material or fatigue.
Even if the cover 34 is attached to the timing belt 30 and the timing belt 30 and the break of the timing belt 30 cannot be visually detected, the control device 21 can surely detect the break of the timing belt 30. .
Thereby, the operational reliability of the robot 21 can be significantly improved. Moreover, this allows the robot 2
As an example including 1, the situation in which an operation abnormality occurs in the entire production system is prevented, and also in this respect, the operational reliability of the robot 21 can be significantly improved.

In this embodiment, the timing belt 3
It is not necessary to use a special component such as a sensor to detect a break of 0, and the number of components is reduced in this regard.

The configuration described in the above embodiment shows one embodiment of the present invention, and does not limit the scope of the present invention. The present invention includes a wide variety of modifications without departing from the spirit of the present invention.

[0021]

As described above, according to the first aspect of the present invention,
A rotating member is fixed to the rotating shaft, and the rotation of the rotating member is released or braked by energizing or de-energizing the braking element. Further, a rotation detection unit is provided near the rotation member of the rotation shaft, and the rotation detection unit rotates with the rotation of the rotation shaft. A rotation detecting element is provided in the vicinity of the rotation detection part, and the rotation of the rotation detection part is detected by the rotation detection element.

Thus, the braking device and the rotation detecting device can be installed at positions close to each other on the rotating shaft so as to be integrally formed. Therefore, it is possible to use a common wiring board or the like on which elements used for these controls are mounted, and it is possible to reduce the size and simplify the overall configuration of the robot.

Further, it is easy to compare a signal relating to the rotation speed of the rotating shaft detected by the rotation detecting device with a signal for rotating the motor driving the rotating shaft at a predetermined rotation speed. Even when the vicinity of the transmission member cannot be visually confirmed from the outside, the breakage of the transmission member can be detected. In addition, this can prevent a situation in which an operation abnormality of the entire system including the industrial robot occurs, and can significantly improve operational reliability.

[Brief description of the drawings]

FIG. 1 is a perspective view of a robot 21 according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a part of the robot 21.

FIG. 3 is a flowchart illustrating the operation of the present embodiment.

FIG. 4 is a perspective view of a conventional robot 1.

[Explanation of symbols]

 21 Robot 23 Motor 25, 29 Pulley 26 Encoder 27 Ball Screw 30 Timing Belt 31 Controller 34 Cover

Claims (1)

[Claims] 1. A motor, a rotating shaft, a slider connected to the rotating shaft and driven to travel with the rotation of the rotating shaft, and a transmission member for transmitting rotation of the rotating shaft of the motor to the rotating shaft. A braking member including: a rotating member fixed to the rotating shaft; and a braking element that brakes or releases the rotation of the rotating member in response to switching between energization cutoff and energization; An industrial robot including: a rotation detection unit provided near a member; and a rotation detection device including a rotation detection element provided near the rotation detection unit.