CROSS-REFERENCE TO RELATED APPLICATION

This application is a 371 of international application of PCT application serial no. PCT/JP2017/009124, filed on Mar. 8, 2017, which claims the priority benefits of Japan application no. 2016-067517, filed on Mar. 30, 2016. The entirety of each of the above-mentioned patent applications is hereby incorporated by reference herein and made a part of this specification.

TECHNICAL FIELD

The present invention relates to a robot including a joint part and an arm.

BACKGROUND ART

In the related art, a robot including a base, a first arm connected to the base via a first joint part, a second arm connected to a tip side of the first arm via a second joint part, and a wrist part connected to a tip side of the second arm via a third joint part is known (for example, refer to Patent Literature 1). In the robot described in Patent Literature 1, the first arm and the second arm are formed in a cylindrical shape. The first to third joint parts and the wrist part include a motor, a reduction gear connected to the motor, an encoder configured to detect a rotational position of the motor, a circuit board on which the encoder and the like are mounted, and a housing in which the motor, the reduction gear, the encoder, and the circuit board are housed.

In the robot described in Patent Literature 1, the motor disposed in the first to third joint parts and the wrist part is a hollow motor, and the reduction gear is a hollow reduction gear. The motor and the reduction gear are disposed on the same axis. In addition, the first to third joint parts and the wrist part include a hollow shaft that is disposed on the inner circumferential side of the motor which is a hollow motor and the inner circumferential side of the reduction gear which is a hollow reduction gear. The hollow shaft is fixed to an output shaft of the reduction gear. In the robot, a wiring drawn out from the circuit board and the like is drawn through the inner circumferential side of the hollow shaft.

CITATION LIST

Patent Literature

Patent Literature 1

U.S. Pat. No. 8,410,732

SUMMARY OF INVENTION

Technical Problem

In the robot described in Patent Literature 1, generally, a wiring drawn out from the wrist part is drawn to the base through the inner circumferential side of the hollow shaft of the third joint part, the inside of the second arm, the inner circumferential side of the hollow shaft of the second joint part, the inside of the first arm and the inner circumferential side of the hollow shaft of the first joint part in this order, and is connected to the controller of the robot. In addition, in the robot described in Patent Literature 1, generally, a wiring drawn out from the third joint part is drawn to the base through the inside of the second arm, the inner circumferential side of the hollow shaft of the second joint part, the inside of the first arm, and the inner circumferential side of the hollow shaft of the first joint part in this order and is connected to the controller of the robot, a wiring drawn out from the second joint part is drawn to the base through the inside of the first arm and the inner circumferential side of the hollow shaft of the first joint part in this order and is connected to the controller of the robot, and a wiring drawn out from the first joint part is drawn to the base and is connected to the controller of the robot.

That is, in the robot described in Patent Literature 1, the wiring drawn out from the wrist part and the wiring drawn out from the third joint part need to be drawn through the inside of the second arm and the inner circumferential side of the hollow shaft of the second joint part, and the wiring drawn out from the wrist part, the wiring drawn out from the third joint part, and the wiring drawn out from the second joint part need to be drawn through the inside of the first arm and the inner circumferential side of the hollow shaft of the first joint part. Therefore, in the robot described in Patent Literature 1, drawing of the wiring is complicated.

Thus, an objective of the present invention is to provide a robot that can simplify wiring drawing even if a plurality of joint parts are provided.

Solution to Problem

In order to achieve the above objective, a robot of the present invention is a robot including a joint part and an arm, wherein the joint part includes a motor, a reduction gear connected to the motor, an output-side member fixed to an output shaft of the reduction gear, a position detection mechanism configured to detect a rotational position of the motor, a circuit board to which the motor and the position detection mechanism are electrically connected, and a case in which the motor, the reduction gear, the position detection mechanism, and the circuit board are housed, wherein the motor and the reduction gear are fixed to the case, and wherein a motor driving circuit configured to drive the motor, a signal transmission circuit configured to output a signal input to the circuit board to the outside of the circuit board, and a connector to which an end of a wiring is connected are mounted on the circuit board.

In the robot of the present invention, the joint part includes a circuit board to which the motor and the position detection mechanism are electrically connected, and a signal transmission circuit configured to output a signal input to the circuit board to the outside of the circuit board and a connector are mounted on the circuit board. Therefore, in the present invention, when the robot includes a plurality of joint parts, one end of the wiring disposed between joint parts is connected to the connector of the circuit board of one joint part and the other end of the wiring is connected to the connector of the circuit board of the other joint part, and thus signal communication between joint parts is possible. Therefore, in the present invention, one end of the wiring disposed between joint parts is connected to the connector of the circuit board of one joint part and the other end of the wiring is connected to the connector of the circuit board of the other joint part, and thus drawing of the wiring between joint parts can be completed. In addition, when drawing of the wiring between joint parts is sequentially performed in this manner, drawing of the wiring of the robot can be completed. As a result, in the present invention, even if the robot includes a plurality of joint parts, drawing of the wiring can be simplified. In addition, in the present invention, since drawing of the wiring can be simplified, assembling of the robot becomes easier.

In addition, in the present invention, the joint part includes a motor, a reduction gear connected to the motor, an output-side member fixed to an output shaft of the reduction gear, a position detection mechanism configured to detect a rotational position of the motor, a circuit board to which the motor and the position detection mechanism are electrically connected, and a case in which the motor, the reduction gear, the position detection mechanism, and the circuit board are housed, and the motor and the reduction gear are fixed to the case. In addition, a motor driving circuit configured to drive the motor, a signal transmission circuit configured to output a signal input to the circuit board to the outside of the circuit board, and a connector to which an end of a wiring is connected are mounted on the circuit board. Therefore, in the present invention, the joint parts can be functionally integrated as a joint module. Thus, in the present invention, it is possible to easily change the number of joint parts of the robot.

In the present invention, for example, the motor is a hollow motor having a hollow rotation shaft, and the reduction gear is a hollow reduction gear which has a hollow input shaft connected to the rotation shaft and is disposed coaxially with the motor. In addition, in the present invention, for example, the joint part includes a cylindrical tubular member inserted into an inner circumferential side of the rotation shaft and the input shaft, a through-hole that communicates with an inner circumferential side of the tubular member is formed at the output-side member, and an opening that opens in a direction orthogonal to an axial direction of the output shaft is formed in the case. In this case, for example, two connectors are mounted on the circuit board, a wiring connected to one connector is drawn through the inner circumferential side of the tubular member and then is drawn out from the through-hole, and a wiring connected to the other connector is drawn out from the opening.

In the present invention, preferably, the output-side member includes a flange part that is formed in an annular shape and disposed outside the case. In such a configuration, it is possible to increase the fixing strength between the member fixed to the output-side member and the output-side member.

In the present invention, for example, the robot includes a first joint part, a second joint part, a third joint part, a fourth joint part, a fifth joint part, and a sixth joint part as the joint parts, a first arm and a second arm as the arms, and a support member fixed to the flange part of the first joint part, wherein at least two connectors including a first connector and a second connector are mounted as the connector on at least the circuit board of the second joint part, the circuit board of the third joint part, the circuit board of the fourth joint part, and the circuit board of the fifth joint part, wherein the first joint part and the second joint part are connected so that an axial direction of the output shaft of the first joint part and an axial direction of the output shaft of the second joint part are perpendicular to each other, and the case of the first joint part is fixed to the flange part of the second joint part, wherein the second joint part and the first arm are connected so that an axial direction of the output shaft of the second joint part and a longitudinal direction of the first arm are perpendicular to each other, and a base end of the first arm is fixed to the case of the second joint part, wherein the first arm and the third joint part are connected so that the longitudinal direction of the first arm and an axial direction of the output shaft of the third joint part are perpendicular to each other, and a tip of the first arm is fixed to the case of the third joint part, wherein the third joint part and the fourth joint part are connected so that the axial direction of the output shaft of the third joint part and an axial direction of the output shaft of the fourth joint part are perpendicular to each other, and the case of the fourth joint part is fixed to the flange part of the third joint part, wherein the fourth joint part and the second arm are connected so that the axial direction of the output shaft of the fourth joint part coincides with a longitudinal direction of the second arm, and a base end of the second arm is fixed to the flange part of the fourth joint part, wherein the second arm and the fifth joint part are connected so that the longitudinal direction of the second arm and an axial direction of the output shaft of the fifth joint part are perpendicular to each other, and a tip of the second arm is fixed to the case of the fifth joint part, wherein the fifth joint part and the sixth joint part are connected so that the axial direction of the output shaft of the fifth joint part and an axial direction of the output shaft of the sixth joint part are perpendicular to each other, and the case of the sixth joint part is fixed to the flange part of the fifth joint part, wherein one end of the wiring drawn out from the case of the sixth joint part is connected to the connector of the sixth joint part and the other end thereof is connected to the first connector of the fifth joint part, wherein one end of the wiring drawn out from the case of the fifth joint part is connected to the second connector of the fifth joint part, and the other end thereof is connected to the first connector of the fourth joint part, wherein one end of the wiring drawn out from the case of the fourth joint part is connected to the second connector of the fourth joint part and the other end thereof is connected to the first connector of the third joint part, wherein one end of the wiring drawn out from the case of the third joint part is connected to the second connector of the third joint part and the other end thereof is connected to the first connector of the second joint part, and wherein one end of the wiring drawn out from the case of the second joint part is connected to the second connector of the second joint part and the other end thereof is connected to the connector of the first joint part.

Advantageous Effects of Invention

As described above, in the present invention, even if the robot includes a plurality of joint parts, drawing of the wiring can be simplified.

