JP2021030370A - robot - Google Patents

Abstract

To provide a robot in which electrical wiring can be prevented from being under excessive load.SOLUTION: A robot comprises: a base; a first arm connected to the base and turning around a first axis; a second arm connected to the first arm and turning around a second axis parallel to the first axis; a third arm which has a hollow portion, is connected to the second arm, turns around a third axis parallel to the first axis, and moves along the third axis; electric wiring provided in the hollow portion; and a rotary member which has a tubular first member fixed to the third arm and having a first terminal in an inner peripheral portion, also has a second member provided inside the first member, relatively rotating with respect to the first member and having, in an outer peripheral portion, a second terminal electrically connected to the electric wiring, and which rotary member maintains a contact state between the first terminal and the second terminal when the second member relatively rotates with respect to the first member.SELECTED DRAWING: Figure 5

Description

The present invention relates to a robot.

In recent years, due to soaring labor costs and a shortage of human resources in factories, automation of manual work has been accelerated by various robots and their peripheral devices. Examples of various robots include articulated robots as shown in Patent Document 1. This articulated robot has a base, a first arm supported by the base, a second arm connected to the first arm, and a third arm supported by the second arm and capable of rotating and moving up and down. The shaft is connected to the base and the second arm, and has a pipe through which wiring is inserted.

Further, in the articulated robot described in Patent Document 1, a force sensor and an end effector are installed at the tip of the shaft. Wiring such as signal lines and power supply lines is connected to these force sensors and end effectors. These wires are routed inside the base, piping, second arm and shaft and are connected to the force sensor and end effector, respectively.

Japanese Unexamined Patent Publication No. 2001-277178

However, in the articulated robot described in Patent Document 1, since the wiring is inserted through the hollow portion in the shaft, the wiring is also twisted as the shaft rotates. Therefore, depending on the amount of rotation of the shaft, the wiring is excessively twisted and the load becomes large.

The present invention has been made to solve at least a part of the above-mentioned problems, and can be realized by the following.

The robot in this application example is a base and
A first arm connected to the base and rotating around the first axis,
A second arm connected to the first arm and rotating around a second axis parallel to the first axis,
A third arm having a hollow portion, which is connected to the second arm, rotates around a third axis parallel to the first axis, and moves along the third axis.
The electrical wiring provided in the hollow portion and
A first member fixed to the third arm, having a tubular shape and having a first terminal on the inner peripheral portion, and an outer circumference provided inside the first member and rotating relative to the first member. The unit has a second member having a second terminal electrically connected to the electric wiring, and when the second member rotates relative to the first member, the first terminal A rotating member that maintains a contact state with the second terminal is provided.

It is a side view which shows the robot system which comprises 1st Embodiment of the robot of this invention. It is a block diagram of the robot system shown in FIG. It is an enlarged vertical sectional view of the 3rd arm shown in FIG. FIG. 3 is a cross-sectional view taken along the line AA in FIG. It is an enlarged vertical sectional view of the 3rd arm shown in FIG. 1 and is the figure which shows the fixing member. It is an enlarged vertical sectional view of the 3rd arm shown in FIG. 1 and is the figure which shows the fixing member. It is a perspective view of the fixing member shown in FIG. 5 and FIG. It is a schematic schematic diagram of the 2nd Embodiment of the robot of this invention.

Hereinafter, the robot of the present invention will be described in detail based on the preferred embodiments shown in the accompanying drawings.
<First Embodiment>
FIG. 1 is a side view showing a robot system including the first embodiment of the robot of the present invention. FIG. 2 is a block diagram of the robot system shown in FIG. FIG. 3 is an enlarged vertical sectional view of the third arm shown in FIG. FIG. 4 is a cross-sectional view taken along the line AA in FIG. FIG. 5 is an enlarged vertical sectional view of the third arm shown in FIG. 1 and is a view showing a fixing member. FIG. 6 is an enlarged vertical sectional view of the third arm shown in FIG. 1 and is a view showing a fixing member. FIG. 7 is a perspective view of the fixing member shown in FIGS. 5 and 6.

Further, in FIGS. 1, 3 and 8, for convenience of explanation, the x-axis, the y-axis and the z-axis are shown as three axes orthogonal to each other. Further, in the following, the direction parallel to the x-axis is referred to as "x-axis direction", the direction parallel to the y-axis is referred to as "y-axis direction", and the direction parallel to the z-axis is referred to as "z-axis direction". Further, in the following, the tip side of each of the illustrated arrows is referred to as "+ (plus)", the proximal end side is referred to as "-(minus)", and the direction parallel to the + x-axis direction is referred to as "+ x-axis direction". The direction parallel to the −x axis direction is referred to as “−x axis direction”, the direction parallel to the + y axis direction is referred to as “+ y axis direction”, and the direction parallel to the −y axis direction is referred to as “−y axis direction”. In other words, the direction parallel to the + z-axis direction is referred to as "+ z-axis direction", and the direction parallel to the -z-axis direction is referred to as "-z-axis direction". Further, the direction around the z-axis and the direction around the axis parallel to the z-axis are referred to as "u-axis directions".

Further, in the following, for convenience of explanation, the + z-axis direction in FIG. 1, that is, the upper side is referred to as "upper" or "upper", and the -z-axis direction, that is, the lower side is also referred to as "lower" or "lower". Regarding the robot arm 20, the base 21 side in FIG. 1 is referred to as a “base end”, and the opposite side, that is, the end effector 7 side is referred to as a “tip”. Further, the z-axis direction in FIG. 1, that is, the vertical direction is defined as the "vertical direction", and the x-axis direction and the y-axis direction, that is, the left-right direction is defined as the "horizontal direction".

The robot system 100 shown in FIGS. 1 and 2 is an apparatus used for operations such as holding, transporting, assembling, and inspecting workpieces such as electronic parts and electronic devices. The robot system 100 includes a control device 1, a robot 2, and an end effector 7. In addition, the robot system 100 includes a display device 41, an input device 42, and the like.

The control device 1 is arranged at a position different from that of the robot 2, that is, outside the robot 2. Further, in the illustrated configuration, the robot 2 and the control device 1 are electrically connected by a cable 200 (hereinafter, also simply referred to as “connection”), but the present invention is not limited to this, and the cable 200 is omitted and wirelessly. Communication may be performed by a method. That is, the robot 2 and the control device 1 may be connected by wired communication or may be connected by wireless communication. Further, the control device 1 may be built in the base 21.

In the illustrated configuration, the robot 2 is a horizontal articulated robot, that is, a SCARA robot. Further, the robot 2 is a so-called ceiling-mounted SCARA robot that is installed and used on the ceiling or the top surface of the installation shelf. The configuration is not limited to the illustrated configuration, and may be installed on the floor and used as described in the second embodiment, or may be installed on the wall and used although not shown.

As shown in FIG. 1, the robot 2 includes a base 21, a first arm 22, a second arm 23, a third arm 24 which is a work head, and a force detecting unit 5. The robot arm 20 is composed of the first arm 22, the second arm 23, and the third arm 24.

Further, the robot 2 includes a drive unit 25 that rotates the first arm 22 with respect to the base 21, a drive unit 26 that rotates the second arm 23 with respect to the first arm 22, and a shaft 241 of the third arm 24. It is provided with a u drive unit 27 for rotating the shaft 241 with respect to the second arm 23, a z drive unit 28 for moving the shaft 241 with respect to the second arm 23 in the z-axis direction, and an angular velocity sensor 29.

As shown in FIGS. 1 and 2, the drive unit 25 is built in the housing 220 of the first arm 22, and has a motor 251 that generates a driving force and a speed reducer 252 that reduces the driving force of the motor 251. And a position sensor 253 that detects the rotation angle of the rotation shaft of the motor 251 or the speed reducer 252.

The drive unit 26 is built in the housing 230 of the second arm 23, and has a motor 261 that generates a driving force, a speed reducer 262 that reduces the driving force of the motor 261, and a rotation shaft of the motor 261 or the speed reducer 262. It has a position sensor 263 that detects the rotation angle of the motor.

The u drive unit 27 is built in the housing 230 of the second arm 23, and is a motor 271 that generates a driving force, a speed reducer 272 that reduces the driving force of the motor 271, and rotation of the motor 271 or the speed reducer 272. It has a position sensor 273 that detects the rotation angle of the shaft.

The z drive unit 28 is built in the housing 230 of the second arm 23, and is a motor 281 that generates a driving force, a speed reducer 282 that reduces the driving force of the motor 281, and rotation of the motor 281 or the speed reducer 282. It has a position sensor 283 that detects the rotation angle of the shaft.

As the motor 251 and the motor 261 and the motor 271 and the motor 281, for example, a servomotor such as an AC servomotor or a DC servomotor can be used.

Further, as the speed reducer 252, the speed reducer 262, the speed reducer 272, and the speed reducer 282, for example, a planetary gear type speed reducer, a wave gear device, or the like can be used. Further, the position sensor 253, the position sensor 263, the position sensor 273 and the position sensor 283 can be, for example, an angle sensor.

The drive unit 25, the drive unit 26, the u drive unit 27, and the z drive unit 28 are each connected to a corresponding motor driver (not shown), and the robot control unit 11 of the control device 1 shown in FIG. 2 via the motor driver. Is controlled by.

Further, as shown in FIG. 1, the angular velocity sensor 29 is built in the second arm 23. Therefore, the angular velocity of the second arm 23 can be detected. Based on the detected angular velocity information, the control device 1 controls the operation of the robot 2.

The base 21 is fixed to the installation surface by, for example, a bolt or the like. The first arm 22 is connected to the lower end of the base 21. The first arm 22 is rotatable around the first axis O1 along the vertical direction with respect to the base 21. When the drive unit 25 that rotates the first arm 22 is driven, the first arm 22 rotates in a horizontal plane around the first axis O1 with respect to the base 21. Further, the position sensor 253 can detect the amount of rotation of the first arm 22 with respect to the base 21.

A second arm 23 is connected to the first arm 22. The second arm 23 is an end portion on the opposite side to the portion connected to the base 21 of the first arm 22, and is connected to the −z axis side.

The second arm 23 is rotatable around the second axis O2 along the vertical direction with respect to the first arm 22. The axial direction of the first axis O1 and the axial direction of the second axis O2 are the same. That is, the second axis O2 is parallel to the first axis O1. When the drive unit 26 that rotates the second arm 23 is driven, the second arm 23 rotates in a horizontal plane around the second axis O2 with respect to the first arm 22. Further, the position sensor 263 can detect the driving amount of the second arm 23 with respect to the first arm 22, specifically, the rotation amount.

Further, the second arm 23 supports the third arm 24 at a position deviated from the second axis O2. The third arm 24 has a shaft 241. The shaft 241 is rotatable about the third axis O3 along the vertical direction with respect to the second arm 23, and is movable in the vertical direction, that is, along the third axis O3 direction. Further, the end of the shaft 241 on the + z axis side is located in the housing 230 of the second arm 23, and the end of the third arm 24 on the −z axis side is from the second arm 23 to the −z axis. It protrudes to the side.

Specifically, the shaft 241 is supported by the rotation support member 242. Although not shown, the rotation support member 242 has an outer cylinder and a rotating body provided inside the outer cylinder. The outer cylinder is fixed to the bottom of the housing 230 of the second arm 23, that is, to the base. On the other hand, although the rotating body is fixed to the shaft 241, it is rotatably supported by the outer cylinder together with the shaft 241 around the z-axis.

A ball screw nut 243 and a spline nut 244 are installed in the middle of the shaft 241 in the longitudinal direction. The ball screw nut 243 and the spline nut 244 are installed on the + z-axis side of the rotation support member 242. Further, the ball screw nut 243 and the spline nut 244 are arranged apart from the + z-axis side in this order.

Although not shown, the ball screw nut 243 has an inner ring and an outer ring concentrically arranged on the outer peripheral side of the inner ring. A plurality of balls (not shown) are arranged between the inner ring and the outer ring, and the inner ring and the outer ring rotate relative to each other as the balls move. The outer ring of the ball screw nut 243 is fixed to an arbitrary portion of the second arm 23.

Further, the inner ring has a portion exposed from the outer ring, and a belt is hung around the exposed portion, and the driving force from the z drive unit 28 is transmitted through the belt. As a result, the shaft 241 can move along the z-axis direction.

The spline nut 244 has an inner ring and an outer ring concentrically arranged on the outer peripheral side of the inner ring. A plurality of balls (not shown) are arranged between the inner ring and the outer ring, and the inner ring and the outer ring rotate relative to each other as the balls move. Further, a spline groove (not shown) is provided on at least one of the inner peripheral portion of the inner ring and the outer peripheral portion of the shaft 241, and a plurality of balls are arranged in the spline groove. The outer ring of the ball screw nut 243 is fixed to an arbitrary portion of the second arm 23.

Further, the inner ring has a portion exposed from the outer ring, and a belt is hung around the exposed portion, and the driving force from the z drive unit 28 is transmitted through the belt. As a result, the inner ring rotates with respect to the outer ring. At this time, the rotational force is converted into a force in the z-axis direction by the spline groove and the plurality of balls, and the shaft 241 can move up and down.

Further, when the shaft 241 rotates around the z-axis, the position sensor 273 shown in FIG. 2 can detect the amount of rotation of the shaft 241 with respect to the second arm 23. Further, when the shaft 241 moves up and down along the z-axis, the position sensor 283 shown in FIG. 2 can detect the amount of movement of the shaft 241 with respect to the second arm 23 in the z-axis direction.

Further, an end effector 7, which is an example of an electronic device, is detachably connected to the tip of the shaft 241. In the illustrated configuration, the end effector 7 is an electric screwdriver that operates by supplying electric power. The end effector 7 is not limited to the configuration shown in the drawing, and examples thereof include those that grip an object to be transported, those that process an object to be transported, those that are used for inspection, and the like.

Further, as shown in FIG. 2, the robot 2 has a force detecting unit 5 that detects a force applied to the shaft 241. The force detection unit 5 is an example of an electronic device. The installation location of the force detection unit 5 is not particularly limited, and examples thereof include a tip portion of the shaft 241 and an intermediate portion of the shaft 241 in the longitudinal direction. The force detection unit 5 is electrically connected to the control device 1 via the electrical wiring 501 described later.

The force detection unit 5 can be configured to have an element made of a piezoelectric material such as quartz. As a result, when the shaft 241 receives an external force, it is transmitted to the force detection unit 5, and the element outputs an electric charge. Information about the amount of this charge is transmitted to the control device 1. Then, the control device 1 can control the operation of the robot arm 20 based on this information.
A control device 1 is connected to such a robot 2 via a cable 200.

As shown in FIG. 2, the control device 1 controls the drive of each part of the robot system 100, such as the robot control unit 11, each part of the robot 2, the end effector 7, and the display device 41.

Further, the control device 1 is configured so that the robot control unit 11, the display control unit 13, the storage unit 14, and the reception unit 15 can communicate with each other. That is, the robot control unit 11, the display control unit 13, the storage unit 14, and the reception unit 15 are connected to each other by wired or wireless communication.

The robot control unit 11 controls the drive of the robot 2, that is, the drive of the robot arm 20, and the like. The robot control unit 11 is a computer in which a program such as an OS is installed. The robot control unit 11 has, for example, a CPU as a processor, a RAM, and a ROM in which a program is stored. Further, the function of the robot control unit 11 can be realized, for example, by executing various programs by the CPU.

The display control unit 13 has a function of causing the display device 41 to display various screens such as windows, characters, and the like. That is, the display control unit 13 controls the drive of the display device 41. The function of the display control unit 13 can be realized by, for example, a GPU or the like.

The storage unit 14 has a function of storing various types of information such as data and programs. The storage unit 14 stores a control program and the like. The function of the storage unit 14 can be realized by a so-called external storage device such as a ROM.

The reception unit 15 has a function of receiving input from the input device 42. The function of the reception unit 15 can be realized by, for example, an interface circuit. When a touch panel is used, for example, the reception unit 15 has a function as an input detection unit for detecting the contact of a user's finger with the touch panel.

The display device 41 includes, for example, a monitor (not shown) composed of a liquid crystal display, an EL display, or the like, and has a function of displaying various images, characters, or the like including various screens such as windows.

The input device 42 is composed of, for example, a mouse, a keyboard, or the like. Therefore, the user can give instructions such as various processes to the control device 1 by operating the input device 42.

Specifically, the user can click on various screens such as windows displayed on the display device 41 with the mouse of the input device 42, or input characters, numbers, etc. with the keyboard of the input device 42. It is possible to give an instruction to the control device 1.

In this embodiment, instead of the display device 41 and the input device 42, a display input device having both the display device 41 and the input device 42 may be provided. As the display input device, for example, a touch panel such as an electrostatic touch panel or a pressure sensitive touch panel can be used. Further, the input device 42 may be configured to recognize sounds such as voice.
The overall configuration of the robot system 100 has been described above.

Next, the internal and peripheral structures of the third arm 24 will be described in detail.
The shaft 241 has a tubular shape having a hollow portion 240. An electric wiring bundle 500 is installed in the hollow portion 240. The electric wiring bundle 500 is a bundle of one or a plurality of electric wirings 501. The electrical wiring 501 is a wiring that electrically connects the control device 1 and the electronic device arranged on the tip end side of the shaft 241. In the present embodiment, the electronic device is an end effector 7 and a force detection unit 5, and the electrical wiring 501 electrically connects these to the control device 1, respectively. As described above, the electrical wiring 501 propagates the control signal, the electric power, the signal regarding the magnitude of the received external force, and the like.

In the present embodiment, the electric wiring bundle 500 will be described as an example in which four electric wirings 501 are bundled in a state of being insulated from each other.

As shown in FIGS. 1 and 3, in the present embodiment, the electric wiring bundle 500 is pulled into the inside of the base 21, the inside of the first arm 22, the inside of the third arm 24, and the hollow portion 240 of the shaft 241. It is being turned. Further, one end of the electric wiring bundle 500 is connected to a rotating member 3 provided in the hollow portion 240.

A part of the electric wiring bundle 500 may be embedded in the solid portion of the shaft 241, or a part of the electric wiring bundle 500 may be routed to the outside of the shaft 241.

As shown in FIG. 3, the rotating member 3 is installed in the hollow portion 240 near the tip end portion of the shaft 241. The rotating member 3 has an outer cylinder 31 as a first member and a rotating body 32 as a second member provided in the outer cylinder 31.

The outer cylinder 31 is fixed to the shaft 241. Therefore, when the shaft 241 rotates around the third axis O3, the outer cylinder 31 rotates together with the shaft 241. Further, the outer cylinder 31 has a diameter-expanded portion 311 provided at an end portion on the −z-axis side thereof and having an enlarged outer diameter. The enlarged diameter portion 311 is exposed on the −z axis side of the shaft 241. The enlarged diameter portion 311 is fixed to the shaft 241 by a screw 312. Thereby, the outer cylinder 31 can be fixed to the shaft 241.

As shown in the figure, the number of places to be screwed may be a plurality or one. Further, the outer cylinder 31 may be fixed to the shaft 241 by another method, omitting the screwing at the enlarged diameter portion 311. The other method is not particularly limited, and examples thereof include a method of press-fitting the outer cylinder 31 into the shaft 241 and a method of fixing the outer cylinder 31 with an adhesive.

Further, the outer cylinder 31 has a bottomed tubular shape having an opening 313 that opens to the + z-axis side. The opening 313 is a portion through which the connector portion 322 of the rotating body 32, which will be described later, is inserted. Further, a recess 314 recessed on the −z axis side is formed on the inner wall of the end of the outer cylinder 31 opposite to the opening 313.

The rotating body 32 is a second member that rotates relative to the outer cylinder 31 inside the outer cylinder 31 as the first member. The rotating body 32 is arranged concentrically with the outer cylinder 31, and its central axis coincides with the third axis O3.

The rotating body 32 is formed from a columnar body portion 321, a connector portion 322 provided so as to project from the end portion of the body portion 321 on the + z axis side to the + z axis side, and an end portion of the body portion 321 on the −z axis side. It has a protruding portion 323 that is provided so as to protrude on the −z axis side.

The outer peripheral portion of the body portion 321 is housed in the outer cylinder 31 apart from the inner peripheral portion of the outer cylinder 31. Further, a plurality of second terminals 34 are provided on the outer peripheral portion of the body portion 321 in the present embodiment.

As described above, the connector portion 322 inserts the inside of the opening 313 of the outer cylinder 31. The connector portion 322 has a tubular shape, and the electric wiring bundle 500 is inserted and fixed inside. Further, the rotating body 32 has a number corresponding to the number of electrical wires 501, and in the present embodiment, has four internal wires 324. When the electric wiring bundle 500 is connected to the connector portion 322, each electric wiring 501 and each internal wiring 324 are electrically connected to each other. Further, each internal wiring 324 is connected to a second terminal 34, which will be described later.

Further, when the outer cylinder 31 and the rotating body 32 rotate relative to each other, the connector portion 322 rotates at the opening 313. Further, since the electric wiring bundle 500 and the rotating body 32 are connected and fixed, when the outer cylinder 31 and the rotating body 32 rotate relatively, the electric wiring bundle 500 is attached to the outer cylinder together with the rotating body 32. It rotates relative to the relative.

The protrusion 323 is inserted into the recess 314 of the outer cylinder 31 as described above. When the outer cylinder 31 and the rotating body 32 rotate relative to each other, the protrusion 323 rotates in the recess 314.

Further, as shown in FIG. 4, a plurality of, four first terminals 33 in the present embodiment are provided on the inner peripheral portion of the outer cylinder 31. Each first terminal 33 is connected to a connection portion 315, which will be described later, via an internal wiring 316. Further, the first terminals 33 are arranged at equal intervals along the third axis O3. Further, each of the first terminals 33 has the same position around the third axis O3, that is, the position of the outer cylinder 31 in the circumferential direction. In other words, the first terminals 33 overlap each other when viewed from the z-axis direction. The positions of the first terminals 33 may be offset from each other when viewed from the z-axis direction.

Since each of these first terminals 33 has the same configuration, one first terminal 33 will be described below as a representative.

As shown in FIG. 4, the first terminal 33 is a so-called brush electrode composed of a plurality of conductive wires 331 in the present embodiment. Each conductive wire is provided so as to project inward from the inner peripheral portion of the outer cylinder 31, that is, toward the rotating body 32.

The base end of each conductive wire 331, that is, the root is connected to the same electrode 332. Further, each conductive wire 331 is installed so as to project so that the tip portions thereof are separated from each other along the circumferential direction of the rotating body 32, that is, the rotation direction. In other words, the roots of the conductive wires 331 are located close to each other, but they are provided so as to project from each other along the rotation direction of the rotating body 32.

Further, each conductive wire 331 is in contact with a second terminal 34 installed on the outer peripheral portion of the body portion 321 of the rotating body 32. The number of the second terminals 34 is the same as the number of the first terminals 33, that is, four are provided. Each second terminal 34 is electrically connected to the electrical wiring 501 via the internal wiring 324. The second terminals 34 are provided apart from each other along the z-axis. The second terminal 34 is provided with electrodes having a predetermined width over the entire circumferential direction of the rotating body 32.

Further, the conductive wire 331 has elasticity and is installed in a state of being pressed toward the rotating body 32 so as to be curved toward the rotating body 32, that is, toward the second terminal 34. .. As a result, even if an impact is applied to the rotating member 3 and the outer cylinder 31 and the rotating body 32 are displaced from each other, the conductive wire 331 can be more reliably maintained in contact with the second terminal 34. it can. Hereinafter, the conductive wire 331, that is, the state in which the first terminal 33 and the second terminal 34 are in contact with each other is simply referred to as a "contact state".

Further, since the tips of the conductive wires 331 face opposite to each other, the contact state is more reliably maintained regardless of which direction the rotating body 32 rotates relative to the outer cylinder 31. be able to.

As described above, the first terminal 33 is a flexible brush electrode. As a result, as described above, even if the outer cylinder 31 and the rotating body 32 are displaced from each other, the contact state can be maintained more reliably and the load applied to the first terminal 33 can be reduced. it can.

Further, the first terminal 33 is provided so as to project toward the rotating body 32 which is the second member. As a result, as described above, the first terminal 33 is pressed toward the second terminal 34 provided on the rotating body 32. Therefore, even if the outer cylinder 31 and the rotating body 32 rotate relative to each other, the contact state can be maintained more reliably.

Further, as described above, the second terminal 34 is provided over the entire area in the circumferential direction of the rotating body 32. As a result, when the outer cylinder 31 and the rotating body 32 rotate relative to each other, the contact state can be maintained regardless of the rotation angle.

Four first terminals 33 composed of such two conductive wires 331 are provided. Each of these four first terminals 33 is electrically connected to the internal wiring 316 via the electrode 332. That is, four electrodes 332 are provided so as to be separated from each other, and four internal wirings 316 are also provided so as to be separated from each other. Each internal wiring 316 is provided in the solid portion of the outer cylinder 31, and is connected to the connecting portion 315 provided on the −z axis side of the outer cylinder 31.

The connection portion 315 is a portion to which four electric wires 502 are connected from the outside, that is, from the −z axis side. Although not shown, the other end of each electrical wiring 502 is electrically connected to the force detection unit 5 and the end effector 7.

According to such a configuration, the electrical wiring 501 is electrically connected to the electrical wiring 502 via the internal wiring 324, the second terminal 34, the first terminal 33, the internal wiring 316, and the connection portion 315. As a result, the force detection unit 5, the end effector 7, and the control device 1 can be electrically connected. Therefore, the control device 1 can receive the output signal of the force detection unit 5 and supply electric power to the end effector 7.

Here, when the robot 2 performs the work, the shaft 241 may be rotated around the third axis O3. When the shaft 241 rotates, the outer cylinder 31 fixed to the shaft 241 rotates together with the shaft 241, but the rotating body 32 is prevented or suppressed from rotating. That is, even if the shaft 241 and the outer cylinder 31 rotate, the relative rotation of the outer cylinder 31 and the rotating body 32 prevents or suppresses the change in the position of the rotating body 32 around the third axis O3. ing. As a result, even if the shaft 241 rotates, it is possible to prevent or suppress the electric wiring bundle 500 fixed to the rotating body 32 from being twisted. Further, as described above, when the outer cylinder 31 and the rotating body 32 rotate relatively, the contact state in which the first terminal 33 and the second terminal 34 are in contact with each other can be maintained. From these facts, no matter how much the shaft 241 rotates, the electric wiring bundle 500 is suppressed from being excessively twisted while maintaining the electrical connection between the force detection unit 5 and the end effector 7 and the control device 1. can do. As a result, there is no limit to the amount of rotation of the shaft 241 and it is possible to rotate the shaft 241 by a desired amount, and it is possible to prevent an excessive load from being applied to the electrical wiring 501.

The electric wiring 502 rotates together with the shaft 241. However, since the force detection unit 5 and the end effector 7 to which the electric wiring 502 is connected also rotate with the shaft 241, the electric wiring 502 is not twisted.

Further, in the robot 2, it is possible to prevent an excessive load from being applied to the electrical wiring 501 even when the shaft 241 moves up and down. This will be described below.

As shown in FIGS. 5 to 7, the robot 2 includes a fixing member 8 for fixing the middle of the electric wiring bundle 500 in the longitudinal direction. The fixing member 8 is inserted into the hollow portion 240 and is configured to be expandable and contractible along the z-axis direction, that is, along the longitudinal direction of the third arm 24.

The fixing member 8 has a first rail member 81 and a second rail member 82 whose overall length is variably configured by sliding with each other. The first rail member 81 and the second rail member 82 are composed of long members having a U-shaped cross section. That is, the first rail member 81 and the second rail member 82 have a tubular shape that is open to the side. Further, the first rail member 81 and the second rail member 82 slide with the other inserted in one. In the present embodiment, the second rail member 82 is inserted into the first rail member 81 and slides.

Although not shown, it is preferable that one of the first rail member 81 and the second rail member 82 has a protrusion, and the other is provided with a groove into which the protrusion is inserted. As a result, it is possible to prevent the first rail member 81 and the second rail member 82 from being unintentionally detached, and it is possible to stably slide the first rail member 81 and the second rail member 82.

The first rail member 81 is arranged along the z-axis direction. The end of the first rail member 81 on the + z-axis side is fixed to the inner top surface of the housing 230 of the second arm 23. The fixing method is not particularly limited, and examples thereof include a method of fixing using a fixing member and a method of fixing using an adhesive or the like.

The second rail member 82 is arranged along the z-axis direction. The second rail member 82 is slidably supported by the first rail member 81 in a state of being inserted into the first rail member 81. Near the end of the second rail member 82 on the + z-axis side, a fixing portion 820 is provided in which the middle of the electric wiring bundle 500 in the longitudinal direction is fixed. The fixing method is not particularly limited, and examples thereof include a method of fixing using a fixing member and a method of fixing using an adhesive or the like.

Further, the end portion of the second rail member 82 on the −z axis side is in contact with the connector portion 322 of the rotating member 3. Further, in the present embodiment, the end portion of the second rail member 82 on the −z axis side is not fixed to the rotating member 3.

The configuration is not limited to this, and the end portion of the second rail member 82 on the −z axis side may be in contact with another portion of the rotating member 3. Further, the end portion of the second rail member 82 on the −z axis side may be fixed to the rotating member 3.

The second rail member 82 is composed of three long plate members 821, 822, and 823. The plate member 822 and the plate member 823 face each other, and the plate member 821 is arranged on the side portion of the plate member 822 and the plate member 823. In other words, a pair of plate members 822 and plate member 823 are provided from the side portion of the plate member 821.

Further, the plate member 821 is provided with an insertion hole 824 for inserting the electric wiring bundle 500. As a result, the electric wiring bundle 500 can be routed through the plate member 821 in the thickness direction, and the degree of freedom of routing is improved.

The fixing member 8 may have a regulating portion that regulates the slide limit of the first rail member 81 and the second rail member 82.

As described above, the robot 2 is inserted into the hollow portion 240, is configured to be expandable and contractible along the longitudinal direction of the third arm 24, and includes a fixing member 8 for fixing the middle of the electrical wiring 501 in the longitudinal direction. According to such a fixing member 8, the electric wiring 501 is fixed to the second rail member 82, and the fixed fixing portion 820 moves up and down in conjunction with the vertical movement of the shaft 241. As a result, even if the shaft 241 moves up and down, the electrical wiring 501 below the fixed portion 820 also moves up and down in conjunction with the vertical movement of the shaft 241. Therefore, it is possible to prevent excessive deformation of the electrical wiring 501. As a result, it is possible to prevent an excessive load from being applied to the electrical wiring 501.

Further, as described above, it is more effective due to the effect of having the rotating member 3, that is, the synergistic effect of being able to prevent an excessive load from being applied to the electrical wiring 501 when the shaft 241 is rotated. It is possible to prevent an excessive load from being applied to the electrical wiring 501.

Further, the fixing member 8 includes a first rail member 81 fixed to the second arm 23 and a second rail member 82 that slides with respect to the first rail member 81 along the longitudinal direction of the first rail member 81. The electrical wiring 501 is fixed to the second rail member 82. Since the electric wiring 501 is fixed to the rail member that moves up and down in conjunction with the shaft 241 in this way, the electric wiring 501 can be moved up and down in conjunction with the up and down movement of the shaft 241. Therefore, excessive deformation of the electrical wiring 501 can be prevented more reliably.

Further, the end portion of the second rail member 82 on the −z axis side, that is, the end portion downward in the vertical direction is in contact with the rotating member 3. As a result, when the shaft 241 moves up and down, the second rail member 82 can be moved up and down while the rotating member 3 fixed to the shaft 241 is in contact with the second rail member 82.

Further, the fixing portion 820, which is a portion to which the electric wiring 501 of the second rail member 82 is fixed, is located outside the hollow portion 240. That is, regardless of the position of the shaft 241 in the z-axis direction, the fixed portion 820 is exposed on the + z-axis side of the shaft 241. As a result, it is possible to effectively prevent or suppress the electrical wiring 501 from coming into contact with or rubbing against the edge of the opening on the + z axis side of the shaft 241. Therefore, it is possible to more effectively prevent the electrical wiring 501 from being overloaded.

The fixing member 8 is not limited to the above configuration. For example, one may be tubular and the other may be rod-shaped to be inserted inside, and the fixing member 8 is a long body having an expansion / contraction mechanism such as a bellows. It may be composed of.

As described above, the robot 2 is connected to the base 21, the first arm 22 which is connected to the base 21 and rotates around the first axis O1, and the first arm 22 which is connected to the first axis O1. A second arm 23 that rotates around the parallel second axis O2 and a second arm 23 that is connected to the second arm 23 and rotates around the third axis O3 that is parallel to the first axis O1 and moves along the third axis O3. A first arm 24 having a hollow portion 240, an electric wiring 501 provided in the hollow portion 240, and a first terminal 33 fixed to the third arm 24 and having a tubular shape and an inner peripheral portion. A second member having an outer cylinder 31 as a member and a second terminal 34 provided inside the outer cylinder 31 that rotates relative to the outer cylinder 31 and is electrically connected to the electric wiring 501 on the outer peripheral portion. And a rotating member 3 that maintains a contact state between the first terminal 33 and the second terminal 34 when the rotating body 32 rotates relative to the outer cylinder 31. Be prepared. As a result, no matter how much the shaft 241 rotates, it is possible to prevent the electrical wiring 501 from being excessively twisted while maintaining the electrical connection between the force detection unit 5 and the end effector 7 and the control device 1. it can. As a result, there is no limit to the amount of rotation of the shaft 241 and it is possible to rotate the shaft 241 by a desired amount, and it is possible to prevent an excessive load from being applied to the electrical wiring 501.

Further, a plurality of pairs of the first terminal 33 and the second terminal 34 are provided so as to be separated from each other along the third axis O3. As a result, the types of electric signals transmitted and received between the force detection unit 5 and the end effector 7 and the control device 1 can be increased, and the robot 2 can perform a wider variety of controls.

<Second Embodiment>
FIG. 8 is a schematic schematic diagram of a second embodiment of the robot of the present invention.

Hereinafter, a second embodiment of the robot of the present invention will be described with reference to FIG. 8, but the differences from the above-described embodiment will be mainly described, and the same matters will be omitted.

As shown in FIG. 8, the robot 2 is a so-called floor-standing type in the present embodiment. The robot 2 has a base 21, a first arm 22, a second arm 23, and a third arm 24, as in the first embodiment. Further, the shaft 241 of the third arm 24 is provided so that the end portion on the + z-axis side projects from the housing 230 of the second arm 23 toward the + z-axis side.

Further, the second arm 23 has an installation member 231 provided on the outside of the housing 230. The installation member 231 is a member for fixing the first rail member 81 protruding from the shaft 241 on the + z axis side. The installation member 231 is provided on the first portion 232 fixed to the outside of the housing 230, the second portion 233 erected on the + z axis side from the first portion 232, and from the second portion 233 to the third axis O3 side. It has a third portion 234, which is provided so as to project. Then, the end of the first rail member 81 on the + z-axis side is fixed to the −z-axis side of the third portion 234.

By providing such an installation member 231, the fixing member 8 can be installed even in a form in which the shaft 241 projects toward the + z axis side of the second arm 23 as in the present embodiment. Therefore, the electric wiring 501 can be fixed to the fixing member 8 in the middle of the longitudinal direction, and the electric wiring 501 can be prevented from being excessively deformed.

The robot of the present invention has been described above based on the illustrated embodiment, but the present invention is not limited to this, and the configuration of each part may be replaced with an arbitrary configuration having the same function. Can be done. Moreover, other arbitrary components may be added. Moreover, you may combine the features of each embodiment.

Further, in the above-described embodiment, the number of rotation axes of the robot arm is three, but the present invention is not limited to this, and the number of rotation axes of the robot arm is, for example, two or four. The above may be sufficient. That is, in the above embodiment, the number of arms is three, but in the present invention, the number of arms is not limited to this, and the number of arms may be, for example, two or four or more.

100 ... Robot system, 1 ... Control device, 11 ... Robot control unit, 13 ... Display control unit, 14 ... Storage unit, 15 ... Reception unit, 2 ... Robot, 3 ... Rotating member, 5 ... Force detection unit, 7 ... End Effector, 8 ... Fixed member, 20 ... Robot arm, 21 ... Base, 22 ... 1st arm, 23 ... 2nd arm, 24 ... 3rd arm, 25 ... Drive unit, 26 ... Drive unit, 27 ... u drive unit , 28 ... z drive unit, 29 ... angular speed sensor, 31 ... outer cylinder, 32 ... rotating body, 33 ... first terminal, 34 ... second terminal, 41 ... display device, 42 ... input device, 81 ... first rail member , 82 ... 2nd rail member, 200 ... cable, 220 ... housing, 230 ... housing, 231 ... installation member, 232 ... 1st part, 233 ... 2nd part, 234 ... 3rd part, 240 ... hollow part, 241 ... Shaft, 242 ... Rotational support member, 243 ... Ball screw nut, 244 ... Spline nut, 251 ... Motor, 252 ... Reducer, 253 ... Position sensor, 261 ... Motor, 262 ... Reducer, 263 ... Position sensor, 271 ... motor, 272 ... reducer, 273 ... position sensor, 281 ... motor, 282 ... reducer, 283 ... position sensor, 311 ... enlarged diameter part, 312 ... screw, 313 ... opening, 314 ... recess, 315 ... connection part , 316 ... Internal wiring, 321 ... Body, 322 ... Connector, 323 ... Projection, 324 ... Internal wiring, 331 ... Conductive wire, 332 ... Electrode, 500 ... Electric wiring bundle, 501 ... Electric wiring, 502 ... Electric Wiring, 820 ... Fixed part, 821 ... Plate member, 822 ... Plate member, 823 ... Plate member, 824 ... Insertion hole, O1 ... 1st axis, O2 ... 2nd axis, O3 ... 3rd axis

Claims (9)

Base and
A first arm connected to the base and rotating around the first axis,
A second arm connected to the first arm and rotating around a second axis parallel to the first axis,
A third arm having a hollow portion, which is connected to the second arm, rotates around a third axis parallel to the first axis, and moves along the third axis.
The electrical wiring provided in the hollow portion and
A first member fixed to the third arm, which is tubular and has a first terminal on the inner peripheral portion, and an outer circumference which is provided inside the first member and rotates relative to the first member. The portion has a second member having a second terminal electrically connected to the electric wiring, and when the second member rotates relative to the first member, the first terminal A robot including a rotating member that maintains a contact state with the second terminal. The robot according to claim 1, wherein the first terminal is a flexible brush electrode. The robot according to claim 1 or 2, wherein the first terminal is provided so as to project toward the second member. The robot according to any one of claims 1 to 3, wherein the second terminal is provided over the entire area in the circumferential direction of the second member. The invention according to any one of claims 1 to 4, which is inserted into the hollow portion, is configured to be expandable and contractible along the longitudinal direction of the third arm, and includes a fixing member for fixing the middle of the electrical wiring in the longitudinal direction. Robot. The fixing member includes a first rail member fixed to the second arm and a second rail member that slides along the longitudinal direction of the first rail member with respect to the first rail member.
The robot according to claim 5, wherein the electrical wiring is fixed to the second rail member. The robot according to claim 6, wherein the second rail member has an end portion lower in the vertical direction in contact with the rotating member. The robot according to claim 6 or 7, wherein the portion of the second rail member to which the electrical wiring is fixed is located outside the hollow portion. The robot according to any one of claims 1 to 8, wherein a plurality of pairs of the first terminal and the second terminal are provided apart from each other along the third axis.

Images