JP5875832B2 - Multi-axis robot arm - Google Patents

Description

  The present invention relates to a multi-axis robot arm having a plurality of movable axes, and more particularly to a multi-axis robot arm having a configuration in which a linear member such as a wire or a cable is connected to the arm.

  Conventionally, various robot arms have been provided, and the following Patent Documents 1 to 3 disclose welding robots having a welding torch at the arm tip. The welding robot is provided with a feeding device for feeding the wire passed through the torch cable toward the tip of the arm in order to supply it to the welding torch. Is installed.

  Here, in the welding robot, welding is performed by freely moving the arm tip sequentially to a position suitable for welding. Since the movement of the arm tip is realized by the arm member rotating or sliding on the joint axis of the arm, a force such as twisting, bending, or pulling acts on the torch cable described above due to the movement of the arm.

  If such a force is applied and the torch cable is deformed and a bent part is generated, the wire cannot be smoothly passed through the torch cable, and there is a possibility that the wire feeding may be hindered. .

  For this reason, Patent Documents 1 to 3 disclose that the wire feeding device is installed so as to be slidable with respect to the arm or installed so as to be swingable with respect to the arm. In this way, if the wire feeding device is installed so as to be movable with respect to the arm, when an excessive force acts on the torch cable, the wire feeding device also moves according to the movement of the torch cable. It is possible to suppress the deformation of the torch cable that releases the force acting on the torch cable and adversely affects the wire feeding.

JP 2011-67893 A JP 2005-254404 A Japanese Utility Model Publication No. 5-60669

  However, in the arm robots disclosed in Patent Documents 1 to 3, the force acting on the torch cable as a result of the movement of the arm tip is transmitted to the wire feeding device by the rigidity of the cable, and the wire is passively applied to the arm. Moved.

  For this reason, in Patent Documents 1 to 3, the force acting on the wire feeding device varies greatly depending on the shape and flexibility of the torch cable. For example, if the cable is soft, the wire feeding device cannot move sufficiently even if the arm tip moves.

  Even if the cable has a certain degree of rigidity, the cable is generally easily deformed, and simply following the movement of the cable causes the wire feeding device to move slightly compared to the movement of the arm tip. End up. This makes it difficult to suppress deformation of the torch cable that adversely affects the wire feeding.

  Such problems are not limited to welding robot torch cables, and linear members such as cables, tubes and pipes used to supply energy, signals, materials, etc. to work tools such as welding torches for arm robots. It can occur throughout.

  The present invention has been made in view of such a problem, and a multi-axis robot arm capable of greatly suppressing deformation of a linear member supported by an arm member even when the posture of the arm changes. The purpose is to provide.

In order to solve the above problems, a multi-axis robot arm according to the present invention includes a multi-axis arm having at least three arm members and at least two movable shafts that connect the arm members to each other, and the arm member. A linear member that supports the tip side and the root side, and at least two movable shafts are interposed between the arm member that supports the tip side and the arm member that supports the root side. In a multi-axis robot arm comprising a linear member, the root of the linear member is installed on the first arm member that supports the base side of the linear member and follows the movement of the multi-axis arm. A follow-up support device that supports the side, the follow-up support device comprising: an arm fixing portion that is fixed to the first arm member; a linear member support portion that supports the linear member; and the arm fixing portion; Said line A follow-up moving part for relatively movably coupled with the member support, an intermediate member, and the first follower movable shaft for connecting the intermediate member and the arm fixing portion relatively movably, A second follow-up movable shaft that connects the intermediate member and the linear member support portion so as to be relatively movable, and the first follow-up movable shaft is the first of the movable shafts. The second movement movable shaft is a shaft that performs the same movement corresponding to the first movable shaft that connects the distal end side of the arm member, and the second followable movable shaft is a second shaft located on the distal end side of the first movable shaft. A follower movable unit that is an axis that performs the same movement corresponding to the movable shaft, and follower drive means for driving the first follower movable shaft and the second follower movable shaft. To do.

  According to the present invention, even when the posture of the arm is changed, the multi-axis robot capable of greatly suppressing the deformation of the linear member by causing the linear member to follow the movement of the arm by the tracking support device. An arm can be provided.

FIG. 1 is a diagram showing a configuration of an articulated robot arm according to an embodiment of the present invention. FIG. 2 is a top enlarged front view of the articulated robot arm according to the embodiment of the present invention. FIG. 3 is an enlarged perspective view of the upper part of the articulated robot arm according to the embodiment of the present invention. FIG. 4 is an enlarged perspective view of the upper part of the articulated robot arm according to the embodiment of the present invention. FIG. 5 is a top enlarged front view of the articulated robot arm according to the embodiment of the present invention. FIG. 6 is an enlarged perspective view of the upper part of the articulated robot arm according to the embodiment of the present invention. FIG. 7 is a top enlarged front view of the articulated robot arm according to the embodiment of the present invention. FIG. 8 is an enlarged perspective view of the upper part of the articulated robot arm according to the embodiment of the present invention. FIG. 9 is a front view of the follow-up support device according to the embodiment of the present invention. FIG. 10 is a perspective view of the follow-up support device according to the embodiment of the present invention. FIG. 11 is a front view of the articulated robot arm in a state where the tracking support device according to the embodiment of the present invention is operated. FIG. 12 is a front view of the articulated robot arm in a state where the tracking support device according to the embodiment of the present invention is operating. FIG. 13 is a front view of the articulated robot arm in a state in which the follow-up support device according to the embodiment of the present invention is operated.

  Hereinafter, an articulated robot arm that is a multi-axis robot arm according to an embodiment of the present invention will be described with reference to the drawings. In the present embodiment, a robot arm used for a welding apparatus that joins metals by brazing will be described as an example. FIG. 1 is a diagram illustrating a configuration of an articulated robot arm according to the present embodiment. FIG. 1A is a front view of the articulated robot arm, and FIG. 1B is a left side view of the articulated robot arm. FIG. 1C is a right side view of the articulated robot arm. Note that the posture shown in FIG. 1 is the basic posture of the articulated robot arm 1 according to the present embodiment.

  FIG. 2 is an enlarged front view showing the upper part of the articulated robot arm according to the embodiment of the present invention. 3 and 4 are enlarged perspective views of the upper part of the articulated robot arm according to the embodiment of the present invention.

  As shown in FIGS. 1 to 4, the articulated robot arm 1 according to this embodiment includes an arm 8, a wire supply device 15 that supplies a wire 18 that serves as a brazing material to the tip of the arm 8, and a wire that will be described later. A follow-up support device 20 for causing the base side of the guide tube 17 to follow the movement of the distal end side of the arm 8 is provided.

  The arm 8 includes a stand 5 installed on the floor, five arm members B-F10B to 10F, and six joint axes A-F11A to 11F that connect the arm members 10 including the stand 5 to each other so as to be relatively movable. And a torch 14 installed at the tip of the arm 8. In the present embodiment, the stand 5 is also one of the arm members constituting the arm 8.

  Each joint shaft 11 includes joint drive actuators A-F 13A to 13F for driving the respective shafts. However, since the joint drive actuators A, E, and F are installed inside the arm 8, illustration is omitted. The stand 5 is connected to a base fixed to the ground by a joint axis A11A which is a rotation axis parallel to the extending direction of the arm 8, and is driven around the joint axis A11A by driving the joint drive actuator A13A. It turns.

  The arm member B10B is connected to the stand 5 by a joint axis B11B that is a rotation axis perpendicular to the extending direction of the arm 8, and is rotated around the joint axis B11B by driving of the joint drive actuator B13B. The arm member C10C is connected to the arm member B10B by a joint axis C11C that is a rotation axis perpendicular to the extending direction of the arm 8, and rotates about the joint axis C11C by driving of the joint drive actuator C13C.

  The arm member D10D is connected to the arm member C10C by a joint axis D11D which is a rotation axis parallel to the extending direction of the arm 8, and rotates about the joint axis D11D by driving the joint drive actuator D13D. The arm member E10E is connected to the arm member D10D by a joint axis E11E that is a rotation axis perpendicular to the extending direction of the arm 8, and is rotated about the joint axis E11E by driving of the joint drive actuator E13E.

  The arm member F10F is connected to the arm member E10E by a joint axis F11F that is a rotation axis parallel to the extending direction of the arm 8, and is rotated about the joint axis F11F by driving of the joint drive actuator F13F. The torch 14 is installed at the tip of the arm member F10F, and the wire 18 supplied to the torch 14 is heated and melted by the flame generated by the torch 14. In addition, illustration of the supply path of the combustion gas to the torch 14, the control cable, etc. is omitted here.

  In this embodiment, the rotation axis is perpendicular to the extending direction of the arm 8, and the joint axes B, C, E11B, 11C, and 11E that move the arm 8 so as to be bent like a wrist are used as wrist joint axes. The joint axes A, D, F11A, 11D, and 11F that are pivot axes parallel to the extending direction of the arm 8 and that move the arm 8 so as to swivel around the extending direction are referred to as swing joint axes.

  The wire supply device 15 includes a wire feeding device 16, a wire guide tube 17, and a wire 18. The wire 18 is accommodated in a roll shape in a wire roll (not shown), and the wire 18 drawn out from the wire roll is supplied to the torch 14. The wire guide tube 17 is a hollow flexible tube interposed between the wire feeder 16 and the torch 14 at the tip of the arm 8.

  That is, the distal end side of the wire guide tube 17 is supported by the arm member F10F via the torch 14 and the like, and the root side is supported by the arm member C10C via the wire feeding device 16 and the follow-up support device 20. A wire 18 is inserted into the wire guide tube 17.

  The wire feeding device 16 is a driving device having a driving roller for feeding the wire 18 to the torch 14 and pulling it back, and is installed on the arm member C10C via the follow-up support device 20.

  The follow-up support device 20 is a device for supporting the base side of the wire guide tube 17 to follow the movement of the arm 8 on the distal end side relative to the arm member C10C on which the wire feeding device 16 is installed. The base side of the wire guide tube 17 is supported via the feeding device 16.

  Thus, by causing the wire guide tube 17 to follow the movement of the tip of the arm 8, the movement of the arm 8 causes the wire guide tube 17 to be excessively bent or twisted, or the wire guide tube 17 is articulated. Interference with peripheral devices around the robot arm 1 can be prevented.

  The follow support device 20 includes an arm fixing frame 21, a feeding device support frame 22, an intermediate frame 23, follow movable axes A, B 25 A, 25 B, link mechanisms A, B 27 A, 27 B, and a wire guide 29. ing. Hereinafter, the configuration of the follow-up support device 20 will be described in detail with further reference to FIGS.

  FIG. 5 is a top enlarged front view of the articulated robot arm according to this embodiment, and FIG. 6 is a top enlarged perspective view of the robot arm according to this embodiment. 5 and 6, in order to facilitate understanding of the configuration of the link mechanism A27A, the wire feeder 16, the feeder support frame 22, the link mechanism B27B, and the like are omitted.

  FIG. 7 is an enlarged front view of the upper part of the articulated robot arm according to the present embodiment, and FIG. 8 is an enlarged perspective view of the upper part of the robot arm according to the present embodiment. 7 and 8, in order to make the configuration of the link mechanism B27B easy to understand, the arm fixing frame 21, the followable movable axes A, B25A, 25B, the link mechanism A27A, and the like are omitted.

  FIG. 9 is a front view of the tracking support device according to the present embodiment, and FIG. 10 is a perspective view of the tracking support device according to the present embodiment.

  As shown in FIG. 6 and the like, the arm fixing frame 21 is fixed to the base side end portion (the lower right end portion in FIG. 6) of the arm member C10C. The intermediate frame 23 is connected to the arm fixing frame 21 by a followable movable axis A25A that is a rotation axis parallel to the extending direction of the arm member C10C. The intermediate frame 23 receives the driving force transmitted by the link mechanism A27A and rotates around the followable movable axis A25A.

  As shown in FIG. 10 and the like, the feeding device support frame 22 is coupled to the intermediate frame 23 by a followable movable shaft B25B that is a rotation axis perpendicular to the extending direction of the arm member C10C. The driving force is transmitted and supplied, and it rotates around the following movable axis B25B.

  Here, the followable movable axis A25A is a follower axis corresponding to the joint axis D11D, and is a rotation axis on the same axis as this. The follow movable axis B25B is a follow axis corresponding to the joint axis E11E, and is a rotation axis parallel to the joint axis E11E. Of course, the followable movable axis A25A and the joint axis D11D may be eccentric.

  The link mechanism A27A is a drive force transmission member that mechanically directly transmits the drive force of the joint drive actuator D13D that drives the joint axis D11D to the followable movable axis A25A. The link mechanism A27A is composed of a high-rigidity metal member, one end of which is fixed to an arm member D10D that rotates about the joint axis D11D, and the other end of the intermediate mechanism 23 that rotates about the followable movable axis A25A. It is fixed.

  Accordingly, the link mechanism A27A functions as a connecting and fixing member that fixes and connects the arm member D10D and the intermediate frame 23 so as to move integrally around the joint axis D11D and the followable movable axis A25A. That is, when the arm member D10D rotates around the joint axis D11D by driving the joint drive actuator D13D, the intermediate frame 23 connected by the link mechanism A27A also follows the arm member D10D around the follow-up rotation axis A25A and is integrally the same. Rotate by an angle.

  When the intermediate frame 23 rotates around the followable movable axis A25A, the followable support device 20 includes a followable movable shaft B25B, a feeding device support frame 22, and a wire that are installed on the front end side of the intermediate frame 23. The feeding device 16 also rotates integrally with the intermediate frame 23.

  The link mechanism B27B is a driving force transmission member that mechanically transmits the driving force of the joint driving actuator E13E that drives the joint axis E11E to the following movable shaft B25B. The link mechanism B27B is configured by combining high-rigidity metal members. One end of the link mechanism B27B is fixed to the arm member E10E that rotates about the joint axis E11E, and the other end rotates about the tracking movable axis B25B. It is fixed to the device support frame 22.

  However, the link mechanism B27B does not fix and connect the arm member D10D and the intermediate frame 23 integrally as in the link mechanism A27A, but once converts the rotational motion of the arm member E10E around the joint axis E11E into linear motion. Then, the arm member E10E and the feeder support frame 22 are connected so that this linear motion is converted again into the rotational motion of the feeder support frame 22 around the followable movable axis B25B and the driving force is transmitted. .

  Therefore, the link mechanism B27B includes an arm-side fixing portion 27B-1 fixed to the arm member E10E, a slide portion 27B-3 that performs linear motion, and a follow-up side fixing portion 27B that is fixed to the feeder support frame 22. -5 and five conversion shafts 27B-7 for converting rotational motion and linear motion (see FIGS. 7 to 10).

  The arm-side fixing portion 27B-1 and the slide portion 27B-3 are connected by three conversion shafts 27B-7, and the arm-side fixing portion 27B-1 is rotated as the arm member E10E rotates around the joint axis E11E. When it rotates, the slide part 27B-3 performs a linear motion. The slide unit 27B-3 is provided with a slide unit 27B-4. The slide unit 27B-3 includes a rail fixed to the slide unit 27B-3 and two units fixed to the link mechanism A27A side. Is restricted to move linearly.

  The slide part 27B-3 and the tracking side fixing part 27B-5 are connected by two conversion shafts 27B-7. When the sliding part 27B-3 performs a linear motion, the tracking side fixing part 27B-5 rotates. Do exercise. In the present embodiment, one of the follow-up side fixing portion 27B-5 and the conversion shaft 27B-7 is installed at substantially the same place.

  The joint axis E11E that the link mechanism B27B follows is a rotation axis in a direction perpendicular to the extending direction of the arm 8, and when the rotation of the arm member E10E is transmitted to the tracking movable axis B25B in a rotational motion, the link mechanism When the whole moves, the arm 8 may be far away from the arm 8, and the operability of the robot arm 1 may be hindered. On the other hand, as in this embodiment, the link mechanism can be configured compactly by once converting into linear motion and transmitting the rotational motion.

  In the present embodiment, the link mechanism B27B is configured to transmit the driving force so as to rotate on the followable movable axis B25B by the same angle as the rotation angle of the joint axis E11E, but the conversion shaft 27B-7. By adjusting the position and the like, the rotation angle on the followable movable axis B25B side can be adjusted as appropriate.

  Subsequently, in the present embodiment, the wire guide tube 17 mainly allows the wire guide tube 17 to follow the torsional movement of the force acting on the wire guide tube 17 when the joint axis F11F rotates. Is rotatably supported by the torch 14 and the wire feeding device 16.

  The wire guide 29 is a guide member that is integrally fixed to the arm member D10D, and rotates integrally with the arm member D10D and the link mechanism A27A around the joint axis D11D that is a pivot joint axis. The wire guide 29 regulates the position of the wire guide tube 17 by passing the wire guide tube 17 through a slit region sandwiched between two rod-shaped members. The wire guide tube 17 is also integrated with the wire guide 29 and the like. Thus, it rotates around the joint axis D11D.

  The configuration of the robot arm 1 has been described above. Next, the operation of the follow-up support device 20 in the present embodiment will be described with reference to FIGS. 11 to 13 are front views of the articulated robot arm in a state in which the follow-up support device according to the present embodiment is operating.

  FIG. 11 shows a state in which only the joint axis E11E is driven by the joint drive actuator E13E from the basic posture of the articulated robot arm 1 shown in FIG. 1, and FIG. 11 (a) shows the arm member counterclockwise in the figure. FIG. 11B shows a state in which the arm member E10E is rotated clockwise in the drawing.

  As shown in FIG. 6A, when the arm member E10E rotates counterclockwise, this rotational force is transmitted to the feeding device support frame 22 by the link mechanism B27B, and the feeding device support frame 22 is also arm member. Following E10E, it rotates counterclockwise around the following movable axis B25B. Further, as shown in FIG. 4B, when the arm member E10E rotates clockwise, the feeding device support frame 22 also rotates clockwise.

  When the feeding device support frame 22 does not rotate following the movement of the arm member E10E, the wire feeding device 17 is interposed in the wire guide tube 17 interposed between the wire feeding device 16 and the torch 14 at the tip of the arm 8. While the side 16 is a fixed end, only the side of the torch 14 moves greatly in the left-right direction in FIG. 11, so that the wire guide tube 17 is bent or pulled.

  For this reason, the wire 18 cannot move smoothly in the wire guide tube 17, thereby causing troubles such as welding, or the wire guide tube 17 being repeatedly subjected to a large stress, thereby deteriorating the tube. Will occur.

  On the other hand, as shown in the present embodiment, by moving the feeder support frame 22 following the movement of the arm member E10E, it is possible to prevent the wire guide tube 17 from being excessively deformed, and to provide a good wire. 18 supply or the like can be realized.

  Subsequently, FIG. 12 shows a state in which only the joint axis D11D is driven by the joint drive actuator D13D from the basic posture of the articulated robot arm 1 shown in FIG. 1, and the arm member D10D is rotated about 60 ° around the joint axis D11D. Show. Further, the rotation direction is clockwise when viewed from the distal end side of the arm 8 (left side in the figure).

  As shown in the figure, when the arm member D10D rotates, the rotational force is transmitted to the intermediate frame 23 by the link mechanism A27A, and the intermediate frame 23 also follows the arm member D10D and is integrated around the followable movable axis A25A. And rotate.

  Therefore, when the intermediate frame 23 does not rotate following the movement of the arm member D10D, the wire feeding device 16 is interposed in the wire guide tube 17 interposed between the wire feeding device 16 and the torch 14 at the tip of the arm 8. Since the side becomes the fixed end, only the torch side 14 rotates around the joint axis D11D together with the arm member D10D, so that an extra force acts on the wire guide tube 17.

  On the other hand, as in the present embodiment, by moving the intermediate frame 23 integrally with the movement of the arm member D10D, it is possible to suppress excessive force from acting on the wire guide tube 17 and to improve the wire 18 Supply, etc. can be realized.

Next, FIG. 13 shows a state in which both the joint axes D, E11D, and 11E are driven by the joint drive actuators D, E13D, and 13E from the basic posture of the articulated robot arm 1 shown in FIG. Joint axis D, E11D, each movement of the 11E is the same as the movement shown in FIGS. 11 and 12 described above, FIG. 13 (a) is a state of rotating the arm member E10E clockwise in FIG It is shown, and FIG. 13 (b) is shows a state of rotating the arm member E10E counterclockwise in FIG.

  As shown in the figure, even when both of the arm members D, E10D, and 10E rotate around the respective axes, the intermediate frame 23 and the feeding device support frame 22 are caused to follow the movement of each arm member 10. By rotating in the same manner, it is possible to prevent an excessive force from acting on the wire guide tube 17.

  As described above, the articulated robot arm 1 according to the present embodiment has been described in detail. However, according to the present embodiment, when the posture of the distal end side of the arm 8 is changed, the distal end side of the wire guide tube 17 is integrated with the arm member F10F. Since the follower supporting device 20 that supports the base side of the wire guide tube 17 via the wire feeding device 16 is configured to move the base side of the wire guide tube 17 in accordance with the movement. It is possible to prevent the wire guide tube 17 from being excessively bent or twisted to adversely affect the feeding of the wire 18.

  Further, the follow-up support device 20 according to the present embodiment includes a follow-up movable shaft 25 that performs the same movement corresponding to a predetermined joint axis 11 of the arm 8, and the wire feeding device 16 is connected via the follow-up movable shaft 25. Since it is configured to follow, the wire feeding device 16 can follow the movement of the arm member 10 around the predetermined joint axis 11 almost accurately, and the wire guide tube 17 is deformed by the posture change of the arm 8. Can be minimized.

  In the present embodiment, among the joint axes D-F11D to 11F located on the distal side of the arm member C10C that supports the base side of the wire guide tube 17 via the wire feeding device 16 and the follow-up support device 20, The follow-up movable shaft B25B that moves in the same manner as the joint axis E11E, which is the wrist joint axis, is installed in the follow-up support device 20, so that the adverse effect on the feeding of the wire 18 due to the posture change of the arm 8 is greatly suppressed. Can do.

  When the joint axes D, F11D, and 11F that are the swivel joint axes are driven, the wire guide tube 17 mainly undergoes torsional deformation, whereas when the joint axis E11E that is the wrist joint axis is driven, the wires The guide tube 17 mainly undergoes bending deformation. Since the wire 18 is troubled when the wire guide tube 17 is bent with a small curvature, at least the wrist joint among the joint shafts 11 on the arm 8 side as in this embodiment. If the followable movable shaft 25 corresponding to the shaft is installed in the follower support device 20, an adverse effect on the feeding of the wire 18 can be greatly suppressed.

  Further, in the present embodiment, among the joint axes D-F11D to 11F that are also located on the tip side from the arm member C10C, the followable movable axis A25A that performs the same movement corresponding to the joint axis D11D that is located on the base side is followed. Also by being installed in the support device 20, the adverse effect on the feeding of the wire 18 due to the posture change of the arm 8 can be greatly suppressed.

  In general, the farther the distance from the distal end portion of the arm 8 is, the longer the moving distance of the distal end portion of the arm 8 is when the joint shaft 11 is driven. Therefore, by setting the followable movable axis A25A corresponding to the joint axis D11D on the base side farthest from the distal end side among the joint axes D-F11D to 11F located on the distal end side with respect to the arm member C10C, the posture of the arm 8 is set. The deformation of the wire guide tube 17 due to the change can be minimized.

  Note that the installation order from the root side to the distal end side when installing a plurality of followable movable shafts 25 on the follower support device 20 is as follows. It is desirable to use the same installation order as When the predetermined joint shaft 11 is driven, all the arm members 10 positioned on the distal end side with respect to the joint shaft 11 rotate around the joint shaft 11. By installing the tracking movable shaft 25 from the base side in the same order, the wire feeding device 16 positioned at the tip of the tracking support device 20 can smoothly follow the tip of the arm 8.

  Although the present embodiment has been described in detail above, the embodiment of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the gist of the present invention. For example, if the number of joint axes constituting the multi-joint robot arm is plural, it can be appropriately changed.

  In addition, the number of follow-up joint axes in the follow-up support device can be changed as appropriate, and it is only necessary to have a plurality of follow-up movable axes corresponding to any of the plurality of joint axes. Further, the place where the follow-up support device is installed can be changed as appropriate, and any arm member in which a plurality of joint shafts are installed on the distal end side can be appropriately installed on the arm member at a predetermined position. For example, you may install in the stand (arm member) fixed with respect to the arm member B in the said embodiment, the arm member C, and a floor surface.

  In the above embodiment, a link mechanism that mechanically transmits the movement of the arm member to the frame of the tracking support device is adopted as means for transmitting the driving force of the joint shaft on the arm side to the tracking movable shaft on the tracking support device side. However, an actuator for driving the following movable shaft may be provided separately.

  In this case, a control means for controlling the follower movable axis to be driven similarly in response to a drive command signal to the joint drive actuator is installed as a follower drive means for causing the follower movable axis to follow the movement of the joint axis. In addition, it is necessary to install a sensor for detecting the movement of the joint axis, and to install a control means for controlling the followable movable axis to be driven in the same manner as the joint axis based on the sensor signal.

  In the above embodiment, the link mechanism as the follower driving means transmits the power so that the follower movable shaft is driven at the same angle as the rotation angle of the joint shaft. However, the tracking angle of the tracking movable shaft may be set to about 80% of the rotation angle of the joint shaft.

  In the above-described embodiment, the case where the movable axes constituting the multi-axis robot arm are the wrist joint axis and the swing joint axis has been described. However, even if a part of the movable axis is a slide axis multi-axis robot arm, The invention can be applied. In the case of a slide shaft, it is necessary to configure the follow-up support device so as to transmit not the rotational driving force but the sliding driving force.

  In the above embodiment, the case where the present invention is applied to a robot arm used in a welding apparatus for joining metals by brazing has been described as an example. However, other welding apparatuses such as arc welding other than brazing are used. First, the present invention can be applied to various multi-axis arm robots such as a transfer device, a cutting device, and a polishing device.

  Also, the linear member is not limited to the wire guide tube of the welding apparatus, but is applied to various linear members connected to the arm, such as cables, tubes, pipes, etc. used to supply energy, signals, substances, etc. to the arm. can do. Furthermore, in the present embodiment, the base side of the linear member is supported by the arm member via the wire feeding device and the tracking support device, but the base of the linear member is simply connected via the relay support portion and the tracking support device. Needless to say, it may be configured to support the side.

DESCRIPTION OF SYMBOLS 1 Articulated robot arm 5 Stand 8 Arm 10 Arm member 11 Joint axis 13 Joint drive actuator 14 Torch 15 Wire supply device 16 Wire feeding device 17 Wire guide tube 18 Wire 20 Tracking support device 21 Arm fixed frame 22 Feeding device support frame 23 Intermediate frame 25 Following movable shaft 27 Link mechanism 29 Wire guide

Claims (5)

A multi-axis arm having at least three arm members, and at least two movable shafts connecting the arm members;
The arm member is a linear member that is supported on the tip side and the root side, and at least two movable shafts are provided between the arm member that supports the tip side and the arm member that supports the root side. In a multi-axis robot arm comprising a linear member interposed,
A tracking support device that is installed on the first arm member that supports the base side of the linear member and supports the base side of the linear member so as to follow the movement of the multi-axis arm;
The following support device is
An arm fixing portion fixed to the first arm member;
A linear member support part for supporting the linear member;
A follow-up movable unit that connects the arm fixing unit and the linear member support unit so as to be relatively movable, and connects the intermediate member, the arm fixing unit, and the intermediate member so as to be relatively movable. A first follower movable shaft, and a second follower movable shaft that connects the intermediate member and the linear member support portion so as to be relatively movable, wherein the first follower movable shaft is movable Of the shafts, the shaft moves in the same manner as the first movable shaft that connects the distal end side of the first arm member, and the second followable movable shaft is the same as the first movable shaft. A follow-up movable part that is an axis that performs the same movement corresponding to the second movable axis located on the distal end side ;
A multi-axis robot arm comprising: follow-up drive means for driving the first follow-up movable axis and the second follow-up movable axis . The follower drive means includes means for driving the first follower movable axis so as to perform the same movement corresponding to the first movable axis, and the second follower movable axis as the second movable axis. The multi-axis robot arm according to claim 1, further comprising: a means for driving the same correspondingly. The means for driving the first following movable shaft so as to make the same movement corresponding to the first movable shaft transmits the movement of the first movable shaft as a driving force on the first following movable shaft. 3. The multi-axis robot arm according to claim 2, wherein the multi-axis robot arm is a link mechanism for connecting and fixing the arm member and the intermediate member connected to the distal end side of the first movable shaft . The means for driving the second following movable shaft so as to make the same movement corresponding to the second movable shaft transmits the movement of the second movable shaft as a driving force in the second following movable shaft. In order to achieve this, a link that converts the rotational motion of the arm member located on the distal end side of the second movable shaft into a linear motion, and further converts the linear motion into a rotational motion again and transmits it to the linear member support portion. 4. The multi-axis robot arm according to claim 2 , wherein the multi-axis robot arm is a mechanism. 5. The multi-axis robot arm according to claim 1, wherein the first movable shaft is a swing joint shaft, and the second movable shaft is a wrist joint shaft. 6.