JP2006321026A - Industrial robot - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an industrial robot which can improve its reliability while reducing its wiring inside the robot. <P>SOLUTION: Servomotors 3a to 3f drive the articulations of a plurality of articulated arms 53, 54 and the articulation of a wrist portion 55 respectively. Servo amplifier units 2a to 2f using a matrix converter electric power converting system as an electric power converter C respectively are arranged in the neighborhood of the respective servomotors 3a to 3f. One 3-phase AC electric source 14 is provided as a power line to the respective servomotors, and the electric power is directly input in parallel to the servo amplifier units using the matrix converter power converting system as the respective electric power converters C from the 3-phase AC power source 14. The converted 3-phase AC power converted by the servo amplifier units using the matrix converter power converting system as the electric power converters C is supplied to the respective servomotors via three electric source cables respectively. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an internal wiring of an articulated industrial robot having a plurality of joint axis arms and connecting a wrist portion having a plurality of joint axes to the tips of the plurality of joint axis arms.

  A general vertical multi-indirect robot has, for example, six axes disclosed in Patent Document 2 as shown in FIG. 5, has a plurality of joint axis arms, and a plurality of joint axes at the tips of the plurality of joint axis arms. It has a structure in which the wrists provided are connected. That is, the turning frame 52 supported on the fixed base 51 so as to be rotatable around the first vertical axis a, and the upright arm 53 supported at the front end of the turning frame 52 so as to be rotatable around the first horizontal vertical axis b. A horizontal arm 54 rotatably supported around the first horizontal vertical axis d at the tip of the upright arm 53, and a wrist 55 having a three-axis joint shaft at the tip of the horizontal arm 54. .

Generally, industrial robots have a servo motor attached to the robot body, and a control device with a built-in servo amplifier is installed separately from the robot body to drive the robot. In such a configuration, the wiring from the servo motor is connected to the control device as it is, and it is difficult to make the connection cable thin. In Patent Document 1, as shown in FIG. 4, each servo motor 11 and position detector 12 are attached to the arm portion 28 of the robot body 15, and the servo amplifier unit 10 for each servo motor is adjacent to each servo motor 11. Are connected to the servo power supply unit 13 disposed on the robot body 15 by wiring 16, and each servo amplifier unit 10 is connected from the servo power supply unit 13 to the robot body 15 and the robot controller. It was proposed to reduce the wiring 9 between 1. Servo power supply unit 13, 32 is a thyristor, 33 is an inverter, 34 is a regenerative circuit, 35 is a smoothing circuit capacitor, 37 is a power line from the inverter 33, 38 is a power line 37 branching to each servo amplifier unit 10 Indicates the wiring to be connected. In Patent Document 2, the servo motor 11 and the position detector 12 are attached to each arm of the arm unit 28, and control from the servo amplifier unit 10, the servo power supply unit 13, and the robot controller 1 that drives each servo motor is performed. A method has been proposed in which a control box 58 in which a control circuit unit for controlling a signal and a position signal from the position detector 12 is integrated into a single unit is fixed to a turning frame 52 of a main body 15 of the robot. Patent Document 3 discloses a matrix converter that converts the voltage, voltage phase, and frequency of a three-phase AC power source into different three-phase AC voltage, voltage phase, and frequency as a power converter. 1) Nakakojimoto, Kobayashi Hirosuke, Satohiko et al., “Proposal of PWM control method for sine wave input / output current of matrix converter”, IEEJ Semiconductor Power Conversion Research Paper No.SPC-03-36, 61 ~ 66 pages are introduced. However, there is no description of applying such a matrix converter to an industrial robot.
Japanese Patent No. 2823673 Japanese Patent Laid-Open No. 9-3000273 JP 2005-102387 A

In Patent Document 1 described above, the reliability decreases because the DC wiring from the servo power supply unit 13 to the servo amplifier 6 extends. Further, even if the structure shown in Patent Document 2 shown in FIG. 5 is adopted, a control circuit unit that controls the control signal from the servo amplifier unit 10, the servo power supply unit 13 and the robot controller 1, the position signal from the position detector 12, and the like. There is only one wiring from the control box 58 to each servo motor 11 that is integrated into one servo motor 11 to each servo motor 11, and in general, there are three wires per servo motor. As shown in Fig. 5 and Fig. 6, with only the power line, there are 3 power lines per servo motor and 12 power lines are controlled for 4 axes (6 for 6 axes). A power line comes out from the box 58 through the upright arm 53 to each servo motor 11 of all joint axes. Further, in the case of a system that drives a large motor, the power line tends to be thick.
SUMMARY OF THE INVENTION An object of the present invention is to solve the above-described problems of the prior art, and an object of the present invention is to provide an industrial robot in which the wiring inside the robot is reduced and the reliability is improved.

For this reason, the present invention provides an industrial robot having a plurality of joint axis arms and connecting a wrist portion having a plurality of joint axes to the tips of the plurality of joint axis arms.
A power converter is arranged adjacent to each of the servo motors that respectively drive the joint axes of the plurality of joint axis arms and the joint axis of the wrist, and one three-phase that is a power line to each of the servo motors An AC power source and a three-phase AC power source are directly input in parallel to the power converters, respectively, and the converted three-phase AC power converted by the power converter is supplied to the servo motor. The above problems have been solved by providing an industrial robot.

  In the present invention, a power converter is arranged adjacent to each of the servo motors that respectively drive the joint axes of a plurality of joint axis arms and the joint axis of the wrist, and one power line to each of the servo motors. The three-phase AC power source and the three-phase AC power source are directly input to the power converters in parallel, and the converted three-phase AC power converted by the power converter is supplied to the servo motor. Therefore, in industrial robots, it has become possible to provide industrial robots with reduced wiring inside the robot and improved reliability.

Preferably, the power converter uses a matrix converter power conversion method, and the servo amplifier unit that drives each servo motor is a servo amplifier unit that uses the matrix converter power conversion method. By eliminating the need for a smoothing circuit capacitor and regenerative circuit and simplifying the configuration of the servo amplifier unit, it has become possible to reduce the size of the servo amplifier unit.
Preferably, each of the three-phase AC power supplies is directly input in parallel to each of the power converters, and the power converter converts the converted three-phase AC power to a servo amplifier unit using each of the matrix converter power conversion methods. The wiring inside the robot was reduced by wiring the 3-phase AC power supply to the servo amplifier attached to the joint of the robot to be supplied.

  The best mode for carrying out the present invention will be described with reference to FIGS. FIG. 1 is a schematic side view of an industrial robot according to an embodiment of the present invention. FIG. 2 is a servo amplifier unit, a servo amplifier unit using a matrix converter power conversion system, a three-phase AC power source, and a position detector. FIG. 3 is a block diagram showing the relationship between the wiring and the robot controller, and FIG. 3 shows a wiring diagram of the three-phase AC power supply, the servo amplifier unit using the matrix converter power conversion method, and each servo motor.

  An industrial robot according to an embodiment of the present invention is an industrial robot having a plurality of joint axis arms 53 and 54 and connecting a wrist portion 55 having a plurality of joint axes to the tips of the plurality of joint axis arms 54. Matrix converter power that is a power converter C adjacent to each of the servo motors 3a, 3b, 3c, 3d, 3e, and 3f that respectively drive the joint axes of the joint shaft arms 53 and 54 and the joint shaft of the wrist 55. Servo amplifier units 2a, 2b, 2c, 2d, 2e, 2f that use the conversion method are arranged, and one 3-phase AC power supply that is the power line to each servo motor 3a, 3b, 3c, 3d, 3e, 3f 14 and 3-phase AC power supply 14 are directly input in parallel to servo amplifier units 2a, 2b, 2c, 2d, 2e, and 2f using the matrix converter power conversion system, which is each power converter C. Matrix converter power conversion method is used The three-phase AC power converted by the servo amplifier units 2a, 2b, 2c, 2d, 2e, and 2f is supplied to each servo motor 3a, 3b, 3c, 3d, 3e, and 3f with three power cables. It is what you do. Servo amplifier units 2a, 2b, 2c, 2d, 2e, 2f using matrix converter power conversion method process sensor signals and various control signals to detect the position and angle of each joint axis, and servo motors 3a, 3b , 3c, 3d, 3e, and 3f. Servo amplifier units 2a, 2b, 2c, and 2d that use a small matrix converter power conversion method by using a matrix converter method as a power conversion method for the servo amplifier unit, eliminating the need for a power regeneration circuit and a smoothing capacitor. , 2e, 2f can be configured. Furthermore, the servo amplifier unit using the matrix converter power conversion method, which is one power converter C, controls only one servo motor as compared with the method disclosed in Patent Document 2. The capacity of the vessel can be reduced. By adopting such a configuration, when comparing the prior art and the present invention, even if the number of power lines passing through the first arm is compared, it can be reduced to 1/4. The embodiments of the present invention have been described above. The present invention can be applied to a robot other than the robot according to the embodiment as long as it has a plurality of joint axes.

The power converter according to the embodiment of the present invention uses a matrix converter power conversion method, and the servo amplifier unit that drives each servo motor is a servo amplifier unit that uses the matrix converter power conversion method. This eliminates the need for a smoothing circuit capacitor and regenerative circuit, and simplifies the configuration of the servo amplifier unit, thereby reducing the size of the servo amplifier unit.
Further, as shown in FIG. 3, servo amplifier units 2a, 2b, 2c, 2d, 2e, and 2f inputs using a matrix converter power conversion system that is a power converter C directly in parallel from a three-phase AC power source 14, respectively. In addition, the internal wiring of the robot is reduced by supplying the converted three-phase AC power to the servo motors 3a, 3b, 3c, 3d, 3e, and 3f.

  According to the present invention, not only the wiring inside the robot is reduced, but also the maintenance of the wiring is facilitated by reducing the wiring. Further, as in the embodiment, by using the matrix converter power conversion method as the power converter, the power regeneration is performed, so that the energy saving effect of the entire robot system can be obtained.

1 shows a schematic side view of an industrial robot according to an embodiment of the present invention. FIG. 2 is a block diagram showing the relationship among one servo motor of FIG. 1, a servo amplifier unit using a matrix converter power conversion method, a three-phase AC power supply, a position detector, wiring, and a robot controller. A wiring diagram of a three-phase AC power supply, a servo amplifier unit using a matrix converter power conversion method, and each servo motor is shown. The block diagram which shows the structure of the conventional 1st industrial robot. The schematic side view of the conventional 2nd industrial robot is shown. FIG. 6 shows a wiring diagram of the conventional second industrial robot of FIG. 5 with a three-phase AC power supply, a control box 58, and servo motors.

Explanation of symbols

2a to 2f: Servo amplifier units that use the matrix converter power conversion system that is the power converter C 3a to 3f: Servo motors
14: Three-phase AC power supply 53, 54; Multiple joint axis arms 55: Wrist

Claims (3)

In an industrial robot having a plurality of joint axis arms and connecting a wrist portion having a plurality of joint axes at the tips of the plurality of joint axis arms,
A power converter is arranged adjacent to each of the servo motors that respectively drive the joint axes of the plurality of joint axis arms and the joint axis of the wrist, and one three-phase that is a power line to each of the servo motors An AC power source and a three-phase AC power source are directly input in parallel to the power converters, respectively, and the converted three-phase AC power converted by the power converter is supplied to the servo motor. Industrial robot.   The power converter uses a matrix converter power conversion system, and the servo amplifier unit that drives each servo motor is a servo amplifier unit that uses the matrix converter power conversion system. Robot.   Each of the three-phase AC power supplies is directly input in parallel to each of the power converters, and the power converter supplies the converted three-phase AC power to each servo amplifier unit using the matrix converter power conversion method. Industrial robot characterized by that.

Images