JP2011051035A - Signal transmission device for robot and robot including the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a space-saving signal transmission device for a robot. <P>SOLUTION: The signal transmission device 60 for a robot for transmitting signals to an end effector 50 of the robot includes: an arm 18; an optical transmission path 62 including a light guide; optical communication means respectively provided on the arm 18 and the end effector 50 for optical communication with each other via the optical transmission path 62; and a driving mechanism 40 for operating the end effector 50. The driving mechanism 40 has a working shaft 30 including a cavity 30a for turning and moving up/down the end effector 50 and a flexible tube for feeding or sucking a gas for operating the end effector 50. The light guide is provided along the flexible tube, and the flexible tube is accommodated in the cavity 30a of the working shaft 30. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a signal transmission device for a robot that transmits a signal for controlling an industrial robot, and a robot including the same.

  In various production sites, industrial robots are frequently used for work automation and labor saving. As an industrial robot, there is known a scalar type robot that has a plurality of rotary arms and has a work shaft at the rotary end of the rotary arm at the end thereof. In this type of scalar type robot, for example, a first arm extending in the horizontal direction is rotatably provided on a base, and a second arm extending in the horizontal direction is provided above the rotating end of the first arm. An arm is rotatably provided, and a work shaft is provided at the rotation end of the second arm. The work shaft is supported so as to be rotatable while being supported by the second arm so as to be movable in the vertical direction with its axis line directed in the vertical direction. A motor for driving the first arm is provided in the base, and a motor for driving the second arm is provided at the base end of the second arm. Further, the second arm is provided with a rotation drive device for rotationally driving the work shaft and an elevating device for raising and lowering the work shaft. An end effector such as a robot hand for performing work on a work target is attached to the lower end of the work shaft (see Patent Document 1).

JP-A-11-170184

  In recent years, with the advancement and precision of work by industrial robots, functions required for end effectors such as robot hands have become more sophisticated and more accurate. Therefore, the end effector is mounted with various sensors including a driving member such as an electromagnetic valve and a camera, and a controller for controlling them. As a result, a large number of signal lines are required to transmit control signals for controlling the operation of the end effector and to exchange data from various sensors. If the electrical transmission and reception of signals between the end effector that operates along with the rotation and elevation of the work shaft and the robot body are performed by electrical wiring, the routing of the wiring becomes extremely complicated and a large space is required. In addition, when working in a clean environment, there is a problem that the wiring is bent with the operation of the work shaft, the wiring is rubbed, and dust is diffused from a part of the coating.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

  Application Example 1 A robot signal transmission device that transmits signals to an end effector of a robot, wherein the optical path is provided in each of an arm, an optical path including an optical waveguide, and the arm and the end effector. Optical communication means for optically communicating with each other via a drive mechanism for operating the end effector, wherein the drive mechanism operates a work shaft having a hollow portion for rotating and lifting the end effector, and operating the end effector. A flexible tube that blows or sucks the gas to be produced, wherein the optical waveguide is provided along the flexible tube, and the flexible tube is accommodated in the hollow portion of the working shaft. Robot signal transmission device.

  According to this configuration, transmission / reception of control signals for controlling the operation of the end effector and data from various sensors provided in the end effector can be performed by optical communication using the optical waveguide. The optical waveguide is embedded in a flexible tube that blows or sucks a gas that operates the end effector, and is accommodated in a hollow portion of a work shaft that moves the end effector. Therefore, the signal wiring routing space is reduced, which can contribute to space saving of the robot. In addition, many signals can be transmitted and received at high speed by optical communication. In addition, it is possible to reduce the generation of dust from part of the coating due to the bending of the wiring caused by the operation of the work axis, and the provision of a robot suitable for a clean environment. Can do.

  Application Example 2 In the flexible tube, the optical waveguide is accommodated in the outer peripheral surface along the axis, and light input / output portions of the optical waveguide are formed at both ends, and the optical communication unit includes the light input / output portion. The robot signal transmission device comprising: an optical transmission / reception unit that transmits / receives an optical signal to / from the tube; and a tube connection unit that positions and connects the flexible tube.

  According to this structure, an optical signal can be transmitted to the optical waveguide accommodated in the flexible tube.

  (Application Example 3) An end effector that performs work on a work target, a work shaft that holds and moves the end effector, a plurality of arms that have the work shaft disposed at a final end, and the robot And a signal transmission device.

  According to this configuration, it is possible to provide a space-saving robot with a reduced wiring space for signal wiring, and it is resistant to noise that can transmit and receive many signals at high speed by optical communication, and is suitable for a clean environment. Robots can be provided.

Schematic which shows the structure of a scalar type robot. Schematic which shows the structure of a work-axis drive part. Schematic which shows the whole structure of the signal transmission apparatus for robots. Sectional drawing which shows the structure of an optical transmission / reception part. The figure explaining an optical transmission line.

  Hereinafter, the robot signal transmission device of this embodiment will be described with reference to the drawings, taking a scalar type robot as an example. In addition, in order to simplify description, each member in the drawings is simplified and partially illustrated in different scales.

(About the structure of a scalar robot)
First, the structure of the scalar robot will be described with reference to FIG. FIG. 1 is a schematic diagram showing the configuration of a scalar robot, (a) is a schematic perspective view of the scalar robot, and (b) is a schematic sectional view of the scalar robot. The scalar robot is installed on a horizontal plane. In the drawing, one direction on the horizontal plane is defined as an X direction, a direction orthogonal to the X direction on the horizontal plane is defined as a Y direction, and a direction orthogonal to the X direction and the Y direction (gravity direction) is defined as a Z direction.

  As shown in FIGS. 1A and 1B, a scalar robot (hereinafter referred to as a robot 100) includes a base 10, a support base 11, and a first arm portion that extends in the horizontal direction with respect to the support base 11. 16, a second arm portion 18 that is joined to the first arm portion 16 and extends in the horizontal direction, a work shaft 30 that extends vertically through the other end of the second arm portion 18, and a work shaft 30 Is provided with a work shaft drive unit 40 that moves up and down and rotates, a robot hand 50 as an end effector attached to the lower end of the work shaft 30, and a control unit 20.

  The base 10 is formed in a rectangular plate shape and disposed on the installation surface of the robot 100, and the support base 11 is disposed on the base 10. As shown in FIG. 1B, a space is formed inside the support base 11, and this space is divided up and down by a support plate 12. A first motor 13 as a drive unit is disposed below the support plate 12. A first speed reducer 14 is disposed above the support plate 12. A control unit 20 that controls the operation of the robot 100 is provided on the bottom side of the support base 11.

A rotation shaft 13 a of the first motor 13 is connected to the input shaft of the first speed reducer 14. An output shaft 14 a is disposed on the upper side of the first speed reducer 14. Therefore, the first speed reducer 14 can decelerate and transmit the rotation of the rotation shaft 13a of the first motor 13 to the output shaft 14a. Note that various reduction mechanisms can be employed for the first reduction gear 14. In the present embodiment, for example, a harmonic drive (registered trademark) is employed. A hole 11 a is formed on the upper surface of the support base 11, and the output shaft 14 a protrudes from the hole 11 a.
The first arm portion 16 is formed in a shape having a substantially rectangular parallelepiped portion, one end is connected to the output shaft 14a, and is provided to be rotatable in the horizontal direction with the output shaft 14a as a fulcrum. That is, when the first motor 13 is driven to rotate, the first arm portion 16 can be rotated in the horizontal direction.

  As shown in FIG. 1B, a second speed reducer 15 and a second motor 17 as a drive unit are stacked in this order in the Z direction on the other end of the first arm portion 16 on the side opposite to the first motor 13. Is arranged. And the output shaft 15a of the 2nd reduction gear 15 is arrange | positioned in the figure Z direction lower side. A hole 16a is formed in the first arm portion 16 at a location facing the second speed reducer 15, and an output shaft 15a protrudes from the hole 16a. A rotation shaft (not shown) of the second motor 17 is connected to the input shaft of the second reduction gear 15. Therefore, the second reduction gear 15 can decelerate the rotation of the rotation shaft 17 a of the second motor 17 and transmit it to the output shaft 15 a of the second reduction gear 15.

  The 2nd arm part 18 is formed in the shape which has a substantially rectangular parallelepiped part, and one end is connected to the output shaft 15a, and it is provided so that it can rotate in a horizontal direction by using the output shaft 15a as a fulcrum. That is, when the second motor 17 is rotationally driven, the second arm portion 18 can be rotated in the horizontal direction. The first motor 13 and the second motor 17 may be any type of motor such as a direct current motor, a pulse motor, and an alternating current motor as long as the rotation direction can be controlled by an electrical signal. In this embodiment, for example, a DC motor is employed.

  As shown in FIGS. 1 (a) and 1 (b), the end of the second arm 18 extends through the end of the second arm 18 opposite to the side connected to the output shaft 15a. A work shaft 30 extending in the vertical direction and a work shaft drive unit 40 that moves the work shaft 30 up and down and rotates are provided. The work shaft drive unit 40 is provided with a lifting device 35 that moves the work shaft 30 in the vertical direction, a rotation drive device 45 that rotates the work shaft 30, and a cover 49 that covers these devices. The cover 49 has a shape along the side edge of the second arm portion 18 and covers the entire area of the end portion of the second arm portion 18 opposite to the second motor 17. The work shaft 30 is driven up and down and rotated by the work shaft drive unit 40. Details of the work shaft drive unit 40 will be described later.

  The robot hand 50 is attached to the lower end of the work shaft 30 described above. The robot hand 50 can move up and down as the work shaft 30 moves up and down and rotates. Moreover, the robot hand 50 performs various operations on the workpiece as the work object. For this reason, for example, taking the work of holding and moving the workpiece as an example, the robot hand 50 holds various sensors (not shown) including a camera for checking the position of the workpiece and the workpiece. Finger part 51, a mechanism part (not shown) for operating the finger part 51, a drive source (not shown) of a mechanism part such as an electromagnetic valve, an air cylinder and various motors, and a controller (not shown) for controlling them. )).

  The control unit 20 includes a central processing unit, a storage unit, a driver circuit, an interface, and the like (not shown). The driver circuit is a circuit that drives the drive sources of the first motor 13, the second motor 17, the work axis drive unit 40, and the robot hand 50. Various sensors, controllers, and the like provided in the driver circuit and the robot hand 50 are connected to the central processing unit. The central processing unit is connected to an external computer via an interface. The storage unit stores program software indicating an operation procedure for controlling the robot 100, data used for control, and the like. The central processing unit comprehensively controls the robot 100 according to the program software.

  The robot 100 having the above-described configuration controls the operations of the first arm unit 16, the second arm unit 18, and the work shaft 30 according to a control signal from the control unit 20, and moves the robot hand 50 to a workpiece position (predetermined value). To the position), and further, the operation of the robot hand 50 can be controlled to perform a predetermined work on the workpiece.

(About work shaft drive structure)
Here, the structure of the work shaft drive unit will be described with reference to FIG. FIG. 2 is a schematic diagram showing the structure of the work shaft drive unit. The X direction and the Z direction shown in FIG. 2 indicate the same directions as the X direction and the Z direction shown in FIG.

  As shown in FIG. 2, the work shaft drive unit 40 includes an elevating device 35 that moves the work shaft 30 in the vertical direction and a rotation drive device 45 that rotates the work shaft 30 by a desired angle. The lifting / lowering device 35 receives a driving force from a third motor (not shown) and can rotate, a ball screw nut 33 screwed to the ball screw shaft 32, and one end of the ball screw nut 33. And an upper connecting member 34 having a work shaft 30 connected to the other end. Each rotating member of the lifting device 35 is formed such that the axis is directed in the vertical direction.

  The ball screw shaft 32 is rotatably supported at the lower end portion by a bearing (not shown) on the second arm portion 18, and supported at the frame 25 standing on the second arm portion 18 by an unillustrated bearing at the upper end portion. Has been. A bearing (not shown) is interposed at a connecting portion between the upper connecting member 34 and the work shaft 30 so that the work shaft 30 can rotate. In addition, this bearing has a stopper part on the upper surface side and restricts the movement of the work shaft 30 in the vertical direction.

  The rotation drive device 45 is rotatably supported on the outer peripheral portion of the work shaft 30 and includes a third reduction device 42 made of a harmonic drive (registered trademark) that receives a rotational force from a fourth motor (not shown), and the third reduction device 42. And a ball spline nut 44 fixed to a flex spline 42a. The ball spline nut 44 has a structure equivalent to that well known in the art, and is engaged with a number of vertical grooves (not shown) formed on the work shaft 30 so as to extend from the lower end portion to the upper end portion. A ball (not shown) is built in so as to be able to circulate, and the rotation of the work shaft 30 is restricted while allowing the work shaft 30 to move in the vertical direction.

  That is, when the ball spline nut 44 rotates integrally with the flex spline 42 a of the third reduction gear 42, the work shaft 30 rotates integrally with the ball spline nut 44 at the same rotation. Further, the ball screw shaft 32 of the lifting device 35 described above rotates and the ball screw nut 33 is raised or lowered, so that the work shaft 30 is moved in the vertical direction while being supported by the ball spline nut 44. The work shaft 30 is supported by being penetrated through the second arm portion 18 by being fitted to the ball spline nut 44.

  The work shaft drive unit 40 having the above-described configuration can move the work shaft 30 penetrating the second arm portion 18 in the vertical direction by a desired distance and can rotate the work shaft 30 by a desired angle. Since the robot hand 50 is fixed to the lower end portion of the work shaft 30, the robot hand 50 can move up and down by a desired distance and can rotate by a desired angle.

  The work shaft 30 is formed in a cylindrical shape, and a longitudinal groove (not shown) formed on the outer peripheral portion so as to extend from a lower end portion into which a large number of balls built in the ball spline nut 44 are engaged to an upper end portion. Are formed, and the inner peripheral portion is hollow to form a hollow portion 30a. In this embodiment, in order to improve space efficiency, air is sent to an air cylinder that is a drive source of a mechanism unit that operates the finger part 51 of the robot hand 50 in the hollow part of the inner peripheral part of the work shaft 30. An air tube composed of a flexible tube that sucks air in order to adsorb a workpiece is incorporated.

(Robot signal transmission device)
Here, the robot signal transmission device will be described with reference to FIGS. FIG. 3 is a schematic diagram showing the overall structure of the robot signal transmission device. 4A and 4B are cross-sectional views illustrating the configuration of the optical transmission / reception unit, FIG. 4A is a cross-sectional view illustrating the configuration of the first optical transmission / reception unit, and FIG. 4B is a cross-section illustrating the configuration of the second optical transmission / reception unit. FIG. 5A and 5B are diagrams for explaining the optical transmission line, where FIG. 5A is an overall view of the optical transmission line, FIG. 5B is a detailed view of both ends of the flexible tube, and FIG. 5C is a structure of the optical waveguide. FIG. The X direction and the Z direction shown in FIG. 3 indicate the same directions as the X direction and the Z direction shown in FIG.

  In recent years, operations and functions required for the robot 100 have become highly sophisticated and highly functional. For this reason, the functions required for the end effector such as the robot hand 50 performing the work are also highly accurate and sophisticated. As a result, the robot hand 50 is equipped with various sensors such as a camera for confirming the type and position of the workpiece and a pressure sensor for detecting the gripping pressure of the finger 51 when gripping the workpiece. In addition, in order to make the operation of the robot hand 50 more precise and faster, a complicated mechanism part provided with a drive source such as an air cylinder and a motor and a controller for controlling them are mounted. As a result, a large number of signal lines are required to receive control signals for controlling the operation of the robot hand 50 and data from various sensors.

  As shown in FIG. 3, the robot signal transmission device 60 controls the robot hand 50 transmitted from the control unit 20 of the robot 100 through the first arm unit 16 and the second arm unit 18, for example, by electric wiring. It plays a role of transmitting signals and data from various sensors transmitted from the robot hand 50 between the second arm unit 18 and the robot hand 50 via the work axis drive unit 40.

  As shown in FIG. 3, the robot signal transmission device 60 includes a first connection portion 61, an optical transmission path 62, and a second connection portion 63 as optical communication means. As shown in FIG. 3 and FIG. 4A, the first connecting portion 61 is disposed on the upper connecting member 34 constituting the lifting device 35 of the work shaft driving portion 40, and the first light as the light transmitting / receiving portion. It is comprised from the transmission / reception part 65 and the 1st tube connection part 66 as a tube connection part. The first optical transmission / reception unit 65 includes an optical connector 67 and a first light incident / exit unit 72. The optical connector 67 includes an optical plug 68 and an optical receptacle 69 to which the optical plug 68 is coupled. An optical fiber cable 70 is connected to the optical plug 68. For example, a control signal, which is an electric signal from the control unit 20 of the robot 100, is transmitted to the optical fiber cable 70 by an optical signal-electric signal converter or an electric signal-optical signal converter (OE / EO converter) (not shown). It is converted into a signal and transmitted. The first light incident / exit section 72 incorporates a lens group 71, has a function of collecting and emitting or entering light, and is provided along the optical axis of the optical receptacle 69.

  That is, an optical signal transmitted through the optical fiber cable 70 is input to the first light incident / exit section 72 via the optical connector 67, collected by the lens group 71, and emitted to an arbitrary point. Conversely, the optical signal input to the first light incident / exit section 72 is collected by the lens group 71, transmitted to the optical fiber cable 70 connected to the optical connector 67, and transmitted toward the control section 20. Is also possible.

  The first tube connection portion 66 has a joint 76 that connects the first air tube 73 housed inside the first arm portion 16 and the second arm portion 18 and a second air tube 75 described later. . The joint 76 has a tube receptacle 76a and a tube receptacle 76b for inserting the first air tube 73 and the second air tube 75, respectively, and a positioning portion 74 capable of positioning the axial direction and the rotation direction of the second air tube 75. ing. The positioning portion 74 is provided in the vicinity of the first light incident / exiting portion 72, and a hole 74 a is formed at a position where light is emitted from the first light incident / exiting portion 72. Note that the positioning method of the second air tube 75 is not particularly limited. The end surface of the second air tube 75 may be per unit in the axial direction, a notch may be provided in the end surface of the second air tube 75, and an engaging portion corresponding to the notch may be provided in the positioning portion 74 of the joint 76 for positioning. .

  As shown in FIG. 5A, the optical transmission path 62 includes a second air tube 75 and an optical waveguide 77 for sending air as a driving source for the mechanism unit of the robot hand 50 described above. As shown in FIG. 5B, the optical waveguide 77 is formed in a tape shape or a thin plate shape using a material having optical characteristics, and includes a core 78 serving as an optical path and a clad 79 surrounding the core. Yes. The core 78 and the clad 79 have different refractive indexes and cause total reflection at the boundary surface to advance light. As a material of the core 78 and the clad 79, for example, a high-purity polyimide resin, a polyamide resin, a polyether resin, or the like is preferably used. In this embodiment, the optical waveguide is formed in a thin tape shape in which the upper and lower sides of the clad 79 are covered with a protective member 77d. Therefore, the optical waveguide 77 of this embodiment has flexibility.

  The second air tube 75 is a flexible tube made of synthetic rubber or the like and having twisting resistance, and has a groove 75a formed on the side surface along the longitudinal direction. The above-described optical waveguide 77 is attached to the groove portion 75 a of the second air tube 75 with an adhesive or the like so as not to protrude from the outer peripheral surface of the second air tube 75. As shown in FIG. 5B, light input / output portions 80a and 80b are formed at both end portions 62a and b of the optical transmission path 62, respectively. The light input / output portions 80a and 80b have a part of the protective member 77d of the optical waveguide 77 removed, and the optical waveguide 77 corresponding to the position of the light input / output portions 80a and b has a right isosceles triangular shape with the light input / output portions 80a and 80b as vertices Dicing process.

  That is, since it is cut by dicing at 45 degrees, the cut surface 81 functions as a mirror. Therefore, the light incident from one light input / output part 80a is reflected by the cut surface 81 and the traveling direction is changed, and proceeds in the core 78 while being totally reflected by the boundary surface between the core 78 and the clad 79. Reflected by one of the cut surfaces 81, the traveling direction of the light is changed, and is emitted from the other light input / output unit 80b. The second air tube 75 is accommodated in the hollow portion of the work shaft 30 of the robot 100 so as to go from the first connection portion 61 to the second connection portion 63. The second air tube 75 is inserted into one of the joints 76 of the first connecting portion 61 described above. At this time, the axial direction and the rotational direction of the second air tube 75 are positioned so that one light input / output portion 80 a overlaps the hole portion 74 a of the positioning portion 74 of the joint 76.

  As shown in FIG. 4B, the second connection unit 63 is disposed in the robot hand 50 and includes a second optical transmission / reception unit 85 and a second tube connection unit 86. The second optical transmission / reception unit 85 includes a second optical input / output unit 88 and an optical signal-electric signal converter or an electric signal-optical signal converter (hereinafter referred to as OE / EO converter 87). Similar to the first light incident / exit section 72, the second light incident / exit section 88 incorporates a lens group 71, and has a function of collecting and emitting or incident light. The OE / EO converter 87 has a function of converting an optical signal into an electric signal and an electric signal into an optical signal. The optical signal transmitting / receiving unit side is directed to the second light incident / exiting unit 88 side, and the second light incident / exited. The part 88 and the optical axis are arranged in common. The electrical signal transmission / reception side is connected to a circuit board 90 provided in the robot hand 50 via an electrical connector 89.

  The second tube connecting portion 86 is provided in the second air tube 75 and the robot hand 50 described above, and third air that sends air to an air cylinder (not shown) that drives a mechanism portion that operates the finger portion 51 of the robot hand 50. It has a joint 93 that connects the tube 92. The joint 93 has tube receptacles 93a and 93b into which the second air tube 75 and the third air tube 92 are respectively inserted, and a positioning portion 94 that can position the axial direction and the rotation direction of the second air tube 75. . The positioning portion 94 is provided in the vicinity of the second light incident / exiting portion 88, and a hole 94a is formed at a position corresponding to the optical axis of the second light incident / exiting portion 88.

  The second air tube 75 is inserted into one of the joints 93. At this time, the second air tube 75 is positioned in the axial direction and the rotational direction so that the other light input / output portion 80 b overlaps the hole portion 94 a of the positioning portion 94 of the joint 93. Note that the positioning method of the second air tube 75 is not particularly limited. Positioning may be performed by setting the end surface of the second air tube 75 in the axial direction or by providing a notch in the end surface of the second air tube 75 and providing an engaging portion corresponding to the notch in the positioning portion 94 of the joint 93. Good.

  The robot signal transmission device 60 having the above-described configuration receives the control signal (optical signal) of the robot hand 50 transmitted from the control unit 20 of the robot 100 via the optical fiber cable 70, and the optical connector 67 of the first connection unit 61. Then, the light is input to the first light incident / exit part 72, condensed by the lens group 71, and irradiated to the hole 74 a provided in the positioning part 74 of the joint 76 of the first tube connection part 66.

  The irradiated optical signal enters the optical waveguide 77 from the light input / output part 80a of the second air tube 75 constituting the optical transmission path 62 inserted into the joint 76 and positioned by the positioning part 74, and enters the optical waveguide 77. It proceeds while being totally reflected at the boundary surface between the core 78 and the clad 79, and is emitted from the other light input / output part 80 b of the second air tube 75. The other end of the second air tube 75 is inserted into the joint 93 of the second connection portion 63 and positioned by the positioning portion 94.

  Therefore, the emitted optical signal is incident on the second optical transmission / reception unit 85 of the second connection unit 63 through the hole 94 a provided in the positioning unit 94 of the joint 93. The incident optical signal is collected by the lens group 71 of the second light incident / exiting unit 88 and input to the optical signal transmitting / receiving unit of the OE / EO converter 87. The input optical signal is converted into an electrical signal by the OE / EO converter 87 and transmitted to the circuit board 90 provided in the robot hand 50 through the electrical connector 89 connected to the electrical signal transmission / reception side.

  In this way, the robot signal transmission device 60 can transmit the control signal of the robot hand 50 transmitted from the control unit 20 of the robot 100 to the circuit board or controller of the robot hand 50. In addition, data from various sensors transmitted from the robot hand 50 can be transmitted to the control unit 20 of the robot 100 through a path reverse to the above.

Hereinafter, effects of the embodiment will be described.
(1) The above-described robot signal transmission device 60 transmits and receives control signals for controlling the operation of the robot hand 50 and data from various sensors provided in the robot hand 50 in the axial direction of the second air tube 75. The optical communication using the optical waveguide 77 provided along the line can be performed. Therefore, it is possible to transmit many signals and large-capacity data at high speed while reducing the influence of noise. The second air tube 75 is accommodated in a hollow portion of the work shaft 30 that holds the robot hand 50 and rotates and lifts it. Therefore, it is possible to reduce the routing space for signal wiring.

  (2) The optical waveguide 77 of the above-described robot signal transmission device 60 is attached to the groove 75a on the side surface of the second air tube 75 having flexibility and twist resistance. Therefore, it is possible to prevent the optical waveguide 77 from being damaged against the bending of the second air tube 75 accompanying the rotation or lifting / lowering of the work shaft 30.

  (3) The robot signal transmission device 60 described above uses an optical waveguide 77 instead of electrical wiring. For this reason, it is possible to reduce the friction between the wires due to the bending of the electric wires accompanying the rotation and raising / lowering of the work shaft 30 and to prevent the diffusion of dust from the wires. In addition, the influence of noise on the signal can be reduced, and the reliability of the robot can be improved.

  DESCRIPTION OF SYMBOLS 20 ... Control part, 30 ... Work axis, 30a ... Hollow part, 34 ... Upper connection member, 40 ... Work axis drive part, 50 ... Robot hand, 60 ... Signal transmission apparatus for robots, 61 ... First connection part, 62 ... Optical transmission path 63... Second connection section 65. First optical transmission / reception section 66. First tube connection section 67. Optical connector 71 71 Lens group 72 72 First light input / output section 75 75 Second Air tube, 76, 93 ... Fitting, 77 ... Optical waveguide, 78 ... Core, 79 ... Cladding, 80a, 80b ... Light input / output part, 85 ... Second optical transmission / reception part, 86 ... Second tube connection part, 87 ... OE / EO converter, 88 ... second light incident / exit section, 100 ... robot.

Claims (3)

A signal transmission device for a robot that transmits signals to an end effector of a robot,
Arm,
An optical path comprising an optical waveguide;
Optical communication means provided in each of the arm and the end effector for optically communicating with each other via the optical path;
A drive mechanism for operating the end effector,
The drive mechanism includes a work shaft having a hollow portion that rotates and lifts the end effector, and a flexible tube that blows or sucks a gas that operates the end effector,
The optical waveguide is provided along the flexible tube,
The robot signal transmission device, wherein the flexible tube is accommodated in the hollow portion of the work shaft. The flexible tube accommodates the optical waveguide in the outer peripheral surface along the axis, and light input / output portions of the optical waveguide are formed at both ends,
The optical communication means includes an optical transmission / reception unit that transmits / receives an optical signal to / from the optical input / output unit, and a tube connection unit that positions and connects the flexible tube. The signal transmission apparatus for robots as described. An end effector for performing work on a work object;
A work shaft for holding and moving the end effector;
A plurality of arms on which the working shaft is disposed at a final end;
A robot signal transmission device according to claim 1 or 2.

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