Robot

Abstract

This robot 10 comprises: a base 11; an arm 20 that is movably supported on the base 11; a cable 30 one end section of which is disposed on the base 11 side and the other end section of which is disposed on the arm 20 side; and one or more clamping parts 50 that fix the cable 30, wherein each of the one or more clamping parts 50 comprises a first holder 51 that is supported in a fixed manner or a movable manner with respect to the base 11 or the arm 20, and a second holder 52 is fixed to the first holder 51 while sandwiching the cable 30 with the first holder 51.

Description

Technical Field

[0001] The present disclosure relates to a robot.

Background Art

[0002] Conventionally, an articulated horizontal robot described in Japanese Patent Application Laid-Open No. 2013-6243 (Patent Document 1 below) has been known. This articulated horizontal robot includes a base, a first horizontal arm rotatably connected to the base, a second horizontal arm rotatably connected to the first horizontal arm, a cable, a wiring duct for guiding the cable, and a cable holding portion disposed inside the second horizontal arm. The second horizontal arm includes a frame fixed to the bottom of the second horizontal arm and holding one end of the wiring duct. The cable holding portion has a corrugated end portion with irregularities and is integrally formed with the frame. The cable is fixed to the cable holding portion by a binding band or the like.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above configuration, for example, when attempting to reduce the size of the second horizontal arm, it is difficult to increase the clamp area, which is the area of the portion where the cable holding portion contacts the cable. Therefore, it is difficult to improve the clamp stability and clamp strength of the cable by the cable holding portion.

Means for Solving the Problems

[0005] The robot of the present disclosure includes a base, an arm movably supported with respect to the base, a cable having one end disposed on the base side and the other end disposed on the arm side, and at least one clamp portion for fixing the cable. Each of the at least one clamp portion includes a first holder fixedly or rotatably supported with respect to the base or the arm, and a second holder fixed to the first holder while sandwiching the cable therebetween.

Advantages of the Invention

[0006] According to the present disclosure, in a robot including a cable, a technique can be provided for improving the clamping stability and clamping strength of the cable while saving space.

Brief Description of the Drawings

[0007]

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[0008] Description of Embodiments of the Present Disclosure First, embodiments of the present disclosure will be listed and described. (1) The robot of the present disclosure includes a base, an arm movably supported with respect to the base, a cable having one end disposed on the base side and the other end disposed on the arm side, and at least one clamp portion for fixing the cable. Each of the at least one clamp portion includes a first holder fixedly or rotatably supported with respect to the base or the arm, and a second holder fixed to the first holder while sandwiching the cable therebetween.

[0009] With such a configuration, the clamp portion for fixing the cable includes a first holder and a second holder that clamps the cable between the first holders, so that it is easy to increase the clamping area of the cable by the clamp portion while saving space. Therefore, the clamping stability and clamping strength of the cable by the clamp portion can be enhanced.

[0010] (2) It is preferable that the arm includes a first arm rotatably supported about a first axis with respect to the base, and a second arm rotatably supported about a second axis parallel to the first axis with respect to the first arm.

[0011] With such a configuration, it is possible to enhance the clamping stability and clamping strength of the cable in a scalar robot.

[0012] (3) The above robot further includes a flexible tube that covers the outside of the cable, a hollow base-side shaft disposed outside the base and fixedly or rotatably supported by the base, a hollow arm-side shaft disposed outside the arm and fixedly or rotatably supported by the arm, a first joint portion that connects one end of the flexible tube to the base-side shaft, and a second joint portion that connects the other end of the flexible tube to the arm-side shaft. It is preferable that the at least one clamp portion includes a base-side clamp portion that is a clamp portion disposed inside the base-side shaft and an arm-side clamp portion that is a clamp portion disposed inside the arm-side shaft.

[0013] With such a configuration, since the cable is covered with a flexible tube, it is possible to improve the cleanliness and dust and water resistance in the usage environment of the robot. In addition, by providing the clamp portion inside the base-side shaft and the arm-side shaft, it is not necessary to provide the clamp portion inside the base and the arm. Therefore, it is possible to enhance the clamping stability and clamping strength of the cable without increasing the size of the base and the arm.

[0014] (4) The above-described robot further includes a pipe member that extends parallel to the first axis and is fixed to the base, a hollow first shaft that extends parallel to the first axis and is supported by the pipe member so as to be rotatable about a third axis parallel to the first axis, a first attachment member that is fixed to the first shaft and fixes the cable, and a second attachment member that is supported so as to be fixed or rotatable with respect to the second arm and fixes the cable. The cable includes a first straight portion that extends parallel to the first axis and is disposed at an end on the base side, and a curved portion that extends from an end of the first straight portion on the side opposite to the base toward the second arm side. The at least one clamp portion includes a first clamp portion that includes the first holder fixed to the pipe member and clamps the first straight portion inside the pipe member, and a second clamp portion that includes the first holder fixed to the first shaft and clamps the first straight portion inside the first shaft. The first attachment member preferably fixes an end of the curved portion on the base side, and the second attachment member preferably fixes an end of the curved portion on the second arm side.

[0015] With such a configuration, when the second clamp portion rotates with respect to the first clamp portion, it is easy to absorb the torsional stress generated in the cable as the first arm and the second arm rotate in the first straight portion. As a result, it is difficult for torsional stress to occur in the curved portion, so it is possible to suppress the concentration of torsional stress and bending stress in the curved portion and damage to the cable.

[0016] (5) In the extended state where the rotating end of the second arm is farthest from the third axis, at least one of the first attachment member and the second attachment member is not disposed between the first axis and the second axis in the extending direction of the first arm, and the curved portion preferably forms an acute angle with a plane perpendicular to the first axis and is led out from the first attachment member toward the second arm side, and forms an acute angle with a plane perpendicular to the first axis and is led out from the second attachment member toward the base side.

[0017] With such a configuration, the curved portion can be derived from each of the first mounting member and the second mounting member at a shallow angle. Therefore, when the bending direction of the curved portion changes as the first arm and the second arm rotate, the deformation of the curved portion becomes smooth. Also, the dimension in the direction parallel to the first axis of the robot can be reduced.

[0018] (6) The above robot further includes a hollow second shaft that extends parallel to the first axis and is supported by the second arm so as to be rotatable about a fourth axis parallel to the first axis. The cable further includes a second straight portion that is continuous with the end portion of the curved portion on the second arm side and extends parallel to the first axis. The at least one clamp portion includes a third clamp portion that is a clamp portion for fixing the second straight portion inside the second arm and includes the first holder fixed to the second arm, and a fourth clamp portion that is a clamp portion for fixing the second straight portion inside the second shaft and includes the first holder fixed to the second shaft. It is preferable that the second mounting member is fixed to the second shaft.

[0019] With such a configuration, when the fourth clamp portion rotates with respect to the third clamp portion, it is easy to absorb the torsional stress generated in the cable as the first arm and the second arm rotate in the second straight portion. As a result, torsional stress is less likely to occur in the curved portion, so it is possible to suppress the concentration of torsional stress and bending stress in the curved portion and damage to the cable.

[0020] (7) The above robot further includes a cover that covers the second arm. The cover includes a stopper that protrudes from the outer surface of the cover. The stopper preferably restricts the second shaft from rotating with respect to the second arm by contacting the second mounting member at an angle equal to or greater than a preset angle.

[0021] With such a configuration, by providing the stopper, it is possible to suppress excessive rotation of the second shaft with respect to the second arm.

[0022] (8) The above robot further includes a coil spring, the second straight portion is disposed inside the coil spring, one end of the coil spring is fixed to the second arm, and the other end of the coil spring is preferably fixed to the fourth clamp portion.

[0023] With such a configuration, by providing the coil spring, it is possible to suppress excessive rotation of the second shaft with respect to the second arm.

[0024] (9) The above robot further includes a flexible tube that covers the outside of the cable, a first joint portion that connects one end of the flexible tube to the first attachment member, and a second joint portion that connects the other end of the flexible tube to the second attachment member. The at least one clamp portion includes a fifth clamp portion and a sixth clamp portion. The first attachment member includes a hollow first block fixed to the first shaft and the fifth clamp portion disposed inside the first block. The second attachment member preferably includes a hollow second block that is fixedly or rotatably supported with respect to the second arm and the sixth clamp portion disposed inside the second block.

[0025] With such a configuration, since the cable is covered with the flexible tube, it is possible to improve the cleanliness, dustproofness, and waterproofness in the usage environment of the robot.

[0026] [Details of Embodiments of the Present Disclosure] Hereinafter, embodiments of the present disclosure will be described. It should be noted that the present disclosure is not limited to these examples, and is defined by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims. In the following description, for a plurality of identical members, only some members may be labeled, and the labels of other members may be omitted.

[0027] [Embodiment 1] <Overall Configuration of the Robot> Embodiment 1 of the present disclosure will be described with reference to FIGS. 1 to 8. In this embodiment, a scalar robot 10 is exemplified. As shown in FIG. 1, the robot 10 includes a base 11, a first arm 21 rotatably supported about a first axis A1 extending vertically with respect to the base 11, a second arm 22 rotatably supported about a second axis A2 extending vertically with respect to the first arm 21, and an operating axis 23 rotatably and vertically movably supported by the second arm 22. Here, the first arm 21 and the second arm 22 constitute the arm 20 of the robot 10. Although not shown, the second arm 22 includes a rotational drive device for rotating the operating axis 23, a lifting device for vertically moving the operating axis 23, and a head for attaching a tool (not shown). The robot 10 includes a cover 24 that covers the operating axis 23 and its peripheral components on the second arm 22.

[0028] <Base> The base 11 is formed in a box shape. The base 11 includes a first arm drive device (not shown) for supporting and driving the first arm 21. This first arm drive device is composed of a motor and a speed reducer. The motor and the speed reducer are provided such that the axial direction thereof points in the vertical direction. This speed reducer decelerates the rotation of the rotation shaft of the motor and transmits it to the first arm 21. The casing of the motor is supported by the base 11, the output shaft of the motor is connected to the input member of the speed reducer, and the output side member, i.e., the casing, of the speed reducer supports the first arm 21.

[0029] <First Arm> The first arm 21 is formed in a box shape having a space inside. Although not shown, one end of the first arm 21 is connected to the speed reducer of the first arm drive device, and the other end is connected to the speed reducer of the second arm drive device. The first arm 21 rotatably supports the second arm 22 via the second arm drive device.

[0030] The drive device for the second arm is for supporting and driving the second arm 22, and is composed of a motor and a speed reducer. These motor and speed reducer are provided such that the axial direction thereof points in the vertical direction. The casing of the motor is supported by the second arm 22, the output shaft of the motor is connected to the input member of the speed reducer, and the output side member, i.e., the casing, of the speed reducer is supported by the first arm 21.

[0031] <Second Arm> The second arm 22 is formed in an elongated box shape extending horizontally from a swing base provided with the motor of the drive device for the second arm. A rotation drive device (not shown) for rotating the operating shaft 23 is provided at the swing end of the second arm 22. A lifting device (not shown) for lifting and lowering the operating shaft 23 is provided at the lower part of the middle portion of the second arm 22.

[0032] <Cable> The robot 10 includes a cable 30 spanned between the base 11 and the second arm 22. As shown in FIG. 2, the cable 30 is a composite cable 34 having a plurality of wiring units 31, single wires 31A, air tubes 32, etc., and a sheath 33 covering these collectively. As shown in FIG. 1, the base 11 side of the cable 30 is led out from the outside of the base 11 from a wiring plug 11B provided on the base 11 or the like. The second arm 22 side of the cable 30 is connected to the drive device for the second arm, the lifting device, the rotation drive device, etc.

[0033] <First Straight Portion, Curved Portion> As shown in FIG. 1, the cable 30 has a first straight portion 30A disposed on the base 11 side and a curved portion 30B extending from the first straight portion 30A toward the second arm 22 side. The first straight portion 30A extends parallel to the first axis A1. The first straight portion 30A is housed inside the pipe member 40 and the first shaft 44. The curved portion 30B has an upwardly convex curved shape. The end of the curved portion 30B on the base 11 side is fixed to the first attachment member 60. The end of the curved portion 30B on the second arm 22 side is fixed to the second attachment member 63.

[0034] <pipe member> A pipe member 40 extending upward is fixed to the upper surface of the base 11. In the present embodiment, a fastening hole 41 to which a bolt B1 can be fastened is provided at the lower end of the pipe member 40 (see FIGS. 3 and 4). By inserting the bolt B1 through the insertion hole 11A provided in the upper surface of the base 11 and fastening this bolt B1 to the fastening hole 41 of the pipe member 40, the pipe member 40 is fixed to the base 11. The pipe member 40 has a cylindrical shape, and the first straight portion 30A is housed inside. Inside the lower portion of the pipe member 40, a first clamp portion 50A for fixing the lower end portion of the first straight portion 30A is provided.

[0035] <first shaft> At the upper end of the pipe member 40, the first shaft 44 is rotatably supported with respect to the pipe member 40. The first shaft 44 is supported by the pipe member 40 via a bearing 43. The rotation axis of the first shaft 44 with respect to the pipe member 40 is the third axis A3. The first shaft 44 has a hollow cylindrical shape. The first straight portion 30A is housed inside the first shaft 44. Inside the first shaft 44, a second clamp portion 50B for fixing the upper end portion of the first straight portion 30A is provided.

[0036] <clamp portion> The robot 10 of this embodiment includes a first clamp portion 50A and a second clamp portion 50B as "at least one clamp portion". The first clamp portion 50A and the second clamp portion 50B have the same configuration, but are fixed at different positions on the robot 10. In the following description, when the first clamp portion 50A and the second clamp portion 50B are not particularly distinguished, they are simply referred to as the clamp portion 50.

[0037] <First holder, second holder> As shown in FIG. 7, the clamp portion 50 includes a first holder 51 and a second holder 52 fixed to the first holder 51. The first holder 51 and the second holder 52 generally have a semi-cylindrical shape. The clamp portion 50 is formed, for example, by performing lathe work, hole processing, etc. on metal. Also, the clamp portion 50 (the first holder 51 and the second holder 52) may be a sheet metal part formed by performing bending processing, etc. on a metal plate as shown in FIG. 8.

[0038] As shown in FIG. 5, the cable 30 is clamped by the first holder 51 and the second holder 52, and the second holder 52 is fixed to the first holder 51, so that the clamp portion 50 fixes the cable 30. When fixing the cable 30 with the clamp portion 50, a clamp rubber 35 is arranged so as to cover the outer periphery of the cable 30. The clamp rubber 35 can protect the cable 30 and enhance the clamp stability.

[0039] As shown in FIG. 7, the first holder 51 and the second holder 52 are provided with positioning holes 53 for positioning with respect to a member (hereinafter referred to as a mating member) to which the clamp portion 50 is fixed. For example, when positioning the first clamp portion 50A with respect to the pipe member 40 (the mating member of the first clamp portion 50A), the arrangement of the first clamp portion 50A is determined based on the relative positional relationship between the positioning holes 53 of the first holder 51 and the second holder 52 and the fastening holes 41 of the pipe member 40 (see FIGS. 3 and 6). Similarly, for the second clamp portion 50B, the second clamp portion 50B is positioned with respect to the first shaft 44 (the mating member of the second clamp portion 50B) using the positioning hole 53.

[0040] As shown in FIG. 7, a fastening hole 54 and an insertion hole 55 are formed in the outer peripheral surface of the first holder 51. The second holder 52 is provided with a fastening hole 56 at a position corresponding to the insertion hole 55 of the first holder 51. As shown in FIG. 5, a bolt B2 is fastened to the fastening hole 54 of the first holder 51 to fix the first holder 51 to the mating member. A bolt B3 is inserted into the insertion hole 55 to fix the second holder 52 to the first holder 51. The bolt B3 is fastened to the fastening hole 56 of the second holder 52.

[0041] The pipe member 40 is provided with bolt receiving holes 42 at positions corresponding to the fastening hole 54 and the insertion hole 55 of the first holder 51. Bolts B2 and B3 are inserted into the bolt receiving holes 42. The inner wall of the bolt receiving hole 42 is adapted to contact the heads of the bolts B2 and B3. When the bolt B2 is inserted into the bolt receiving hole 42 and fastened to the fastening hole 54 of the first holder 51, the first holder 51 is fixed to the pipe member 40. When the bolt B3 is inserted into the bolt receiving hole 42 and the insertion hole 55 of the first holder 51 and fastened to the fastening hole 56 of the second holder 52, the second holder 52 is fixed to the first holder 51. At this time, the cable 30 (the first straight portion 30A) disposed between the first holder 51 and the second holder 52 is clamped by the first holder 51 and the second holder 52, so that the first clamp portion 50A fixes the cable 30 (the first straight portion 30A).

[0042] Although not shown, similar bolt receiving holes are also formed in the first shaft 44, and the fixing of the first holder 51 of the second clamp portion 50B to the first shaft 44 and the fixing of the cable 30 (first straight portion 30A) by the second clamp portion 50B can be achieved by bolt fastening.

[0043] According to the clamp portion 50 of the present embodiment, it is easy to increase the area (clamp area) of the portion for fixing the cable 30 in a space-saving manner. Therefore, the clamp stability and clamp strength of the cable 30 by the clamp portion 50 can be enhanced. Further, in the present embodiment, since the clamp portion 50 is provided outside the base 11 and the second arm 22, an increase in the size of the base 11 and the second arm 22 can be suppressed.

[0044] As shown in FIG. 1, a first attachment member 60 is fixed to the upper portion of the first shaft 44. In the present embodiment, the first attachment member 60 includes a hollow first block 61 and a first cable fixing portion 62 for fixing the cable 30. The end portion on the base 11 side of the curved portion 30B is accommodated inside the first block 61. The first cable fixing portion 62 is a so-called capcon. The first cable fixing portion 62 is attached to the opening of the first block 61 and fixes the end portion on the base 11 side of the curved portion 30B. Although not shown, at least one of the clamp portions 50 arranged closer to the base 11 side than the first attachment member 60, that is, the first clamp portion 50 and the second clamp portion 50, may be configured to fix the cable 30 not covered by the sheath 33, that is, the bare wiring unit 31, the single wire 31A, the air tube 32, etc.

[0045] A second attachment member 63 is fixed to a stay 22A provided on the second arm 22. The second attachment member 63 includes a hollow second block 64 and a second cable fixing portion 65 for fixing the cable 30. An end portion of the curved portion 30B on the second arm 22 side is accommodated inside the second block 64. The second cable fixing portion 65 is a so-called capcon. The second cable fixing portion 65 is attached to an opening of the second block 64 and fixes an end portion of the curved portion 30B on the second arm 22 side.

[0046] The state in which the pivoting end of the second arm 22 shown in FIG. 1 is most distant from the third axis A3 is an extended state in which the first arm 21 supported by the base 11 and the second arm 22 supported by the first arm 21 are arranged linearly in series. In the present embodiment, in the extended state, at least one (both in FIG. 1) of the first attachment member 60 and the second attachment member 63 is not arranged between the first axis A1 and the second axis A2 in the extending direction of the first arm 21 (the left-right direction in the drawing of FIG. 1). Also, the direction in which the curved portion 30B is led out from the first attachment member 60 toward the second arm 22 side and the direction in which the curved portion 30B is led out from the second attachment member 63 toward the base 11 side form an acute angle with a plane perpendicular to the first axis A1 (here, a horizontal plane). Specifically, the leading-out directions of these curved portions 30B form a shallow angle upward from the horizontal direction (the left-right direction in the drawing of FIG. 1).

[0047] By providing the first attachment member 60 and the second attachment member 63 as described above, the curved portion 30B curves gently. Therefore, the bending stress applied to the curved portion 30B can be reduced. Accordingly, when the bending direction of the curved portion 30B changes as the first arm 21 and the second arm 22 pivot, the deformation of the curved portion 30B becomes smooth. Also, compared to the case where the curved portion 30B is greatly curved in an inverted U shape, the overall height (the dimension in the vertical direction) of the robot 10 can be reduced.

[0048] In this embodiment, the first shaft 44 is rotatable with respect to the pipe member 40. Inside the pipe member 40, a first clamp portion 50A for fixing the first straight portion 30A is fixed, and inside the first shaft 44, a second clamp portion 50B for fixing the first straight portion 30A is fixed. Therefore, when the first shaft 44 rotates with respect to the pipe member 40, the first straight portion 30A disposed between the first clamp portion 50A and the second clamp portion 50B is twisted. For this reason, when torsional stress is applied to the cable 30 as the first arm 21 and the second arm 22 rotate, the first shaft 44 rotates with respect to the pipe member 40, and the torsional stress is mainly absorbed in the first straight portion 30A. As a result, almost no torsional stress is generated in the curved portion 30B to which mainly bending stress is applied. Therefore, since the simultaneous generation of bending stress and torsional stress in the curved portion 30B is suppressed, damage to the cable 30 can be suppressed.

[0049] [Operational Effects of Embodiment 1] As described above, the robot 10 of Embodiment 1 includes a base 11, an arm 20 movably supported with respect to the base 11, a cable 30 having one end disposed on the base 11 side and the other end disposed on the arm 20 side, and at least one clamp portion 50 for fixing the cable 30. Each of the at least one clamp portion 50 includes a first holder 51 fixedly or rotatably supported with respect to the base 11 or the arm 20, and a second holder 52 fixed to the first holder 51 while sandwiching the cable 30 between the first holder 51.

[0050] According to such a configuration, the clamp portion 50 for fixing the cable 30 includes the first holder 51 and the second holder 52 that sandwiches the cable 30 between the first holder 51, so that it is easy to increase the clamping area of the cable 30 by the clamp portion 50 with less space. Therefore, the clamping stability and clamping strength of the cable 30 by the clamp portion 50 can be enhanced.

[0051] In Embodiment 1, the arm 20 includes a first arm 21 rotatably supported about a first axis A1 with respect to the base 11, and a second arm 22 rotatably supported about a second axis A2 parallel to the first axis A1 with respect to the first arm 21.

[0052] According to such a configuration, in the scalar robot 10, the clamp stability and clamp strength of the cable 30 can be enhanced.

[0053] The robot 10 of Embodiment 1 further includes a pipe member 40 extending parallel to the first axis A1 and fixed to the base 11, a hollow first shaft 44 extending parallel to the first axis A1 and rotatably supported by the pipe member 40 about a third axis A3 parallel to the first axis A1, a first attachment member 60 fixed to the first shaft 44 and fixing the cable 30, and a second attachment member 63 fixed to the second arm 22 and fixing the cable 30. The cable 30 includes a first straight portion 30A extending parallel to the first axis A1 and disposed at an end on the base 11 side, and a curved portion 30B extending from an end of the first straight portion 30A on the side opposite to the base 11 toward the second arm 22 side. At least one clamp portion 50 includes a first clamp portion 50A that is a clamp portion 50 having a first holder 51 fixed to the pipe member 40 and fixing the first straight portion 30A inside the pipe member 40, and a second clamp portion 50B that is a clamp portion 50 having a first holder 51 fixed to the first shaft 44 and fixing the first straight portion 30A inside the first shaft 44. The first attachment member 60 fixes an end of the curved portion 30B on the base 11 side, and the second attachment member 63 fixes an end of the curved portion 30B on the second arm 22 side.

[0054] According to such a configuration, when the second clamp portion 50B rotates with respect to the first clamp portion 50A, it is easy to absorb the torsional stress generated in the cable 30 due to the rotation of the first arm 21 and the second arm 22 at the first straight portion 30A. As a result, torsional stress is less likely to occur in the curved portion 30B, so that it is possible to suppress the concentration of torsional stress and bending stress in the curved portion 30B and damage to the cable 30.

[0055] In Embodiment 1, in the extended state where the rotating end portion of the second arm 22 is farthest from the third axis A3, at least one of the first mounting member 60 and the second mounting member 63 is not arranged between the first axis A1 and the second axis A2 in the extending direction of the first arm 21. The curved portion 30B forms an acute angle with respect to the plane (horizontal plane) perpendicular to the first axis A1 and is led out from the first mounting member 60 toward the second arm 22 side, and forms an acute angle with respect to the plane perpendicular to the first axis A1 and is led out from the second mounting member 63 toward the base 11 side.

[0056] According to such a configuration, the curved portion 30B can be led out from each of the first mounting member 60 and the second mounting member 63 at a shallow angle. Therefore, when the bending direction of the curved portion 30B changes as the first arm 21 and the second arm 22 rotate, the deformation of the curved portion 30B becomes smooth. Also, the dimension in the direction parallel to the first axis A1 (vertical direction) of the robot 10 can be reduced.

[0057] [Embodiment 2] Embodiment 2 of the present disclosure will be described with reference to FIGS. 9 to 13. In the robot 110 of Embodiment 2, the configuration provided around the end portion of the cable 130 on the second arm 22 side is different from that of Embodiment 1. Since the other configurations, operations, and effects are the same as those of Embodiment 1, the same reference numerals as those in Embodiment 1 are given to the members equivalent to those in Embodiment 1, and detailed descriptions are omitted.

[0058] [Second straight portion] In the present embodiment, as shown in FIG. 9, the cable 130 is spanned between the base 11 and the second arm 22. The cable 130 has a first straight portion 30A, a curved portion 30B, and a second straight portion 130C extending parallel to the first axis A1 from the end portion of the curved portion 30B on the second arm 22 side.

[0059] [Second shaft] The second arm 22 includes a cylindrical holding portion 70 fixed to the upper surface of the stay 22A of the second arm 22. A second shaft 72 is supported on the holding portion 70 via a bearing 71. The second shaft 72 is rotatable about a fourth axis A4 with respect to the holding portion 70. The second shaft 72 has a hollow cylindrical shape. A second straight portion 130C is accommodated inside the holding portion 70 and the second shaft 72. Inside the second shaft 72, a fourth clamping portion 150B for fixing the upper end portion of the second straight portion 130C is provided. The fourth clamping portion 150B is configured in the same manner as the clamping portion 50 of the first embodiment. A second attachment member 63 is fixed to the upper portion of the second shaft 72.

[0060] As shown in FIG. 10, a first holder 151 of a third clamping portion 150A is fixed to the lower surface of the stay 22A of the second arm 22. The third clamping portion 150A is a sheet metal part. The first holder 151 of the third clamping portion 150A has a semi-cylindrical shape and includes a main body portion 151A for fixing the cable 130 and an extension portion 151B extending from the main body portion 151A. The upper portion of the extension portion 151B is fixed to the lower surface of the stay 22A by bolt fastening. Therefore, the third clamping portion 150A is disposed inside the second arm 22. The third clamping portion 150A fixes the lower end portion of the second straight portion 130C. Specifically, a second holder 152 of the third clamping portion 150A is bolt-fastened to the first holder 151 of the third clamping portion 150A.

[0061] In the second embodiment, by rotating the second shaft 72 with respect to the holding portion 70, it is possible to absorb the torsional stress generated in the cable 130 in the second straight portion 130C. Therefore, since the occurrence of bending stress and torsional stress simultaneously in the curved portion 30B is further suppressed compared to the first embodiment, damage to the cable 130 can be further suppressed.

[0062] As shown in Fig. 11, in the leading portion of the cable 130 fixed by the first attachment member 60 or the second attachment member 63, at least one of the clamp portions 50, that is, the first clamp portion 50A, the second clamp portion 50B, the third clamp portion 150A, and the fourth clamp portion 150B (the third clamp portion 150A in Fig. 11) may be configured to fix the cable 130 not covered by the sheath 33, that is, the loose wiring unit 31, the single wire 31A, the air tube 32, etc.

[0063] When the loose wiring unit 31, the single wire 31A, the air tube 32, etc. are fixed to the third clamp portion 150A, the torsional rigidity of the second straight portion 130C between the third clamp portion 150A and the fourth clamp portion 150B becomes low. Therefore, the second straight portion 130C is likely to be twisted. That is, the second shaft 72 is likely to rotate with respect to the holding portion 70.

[0064] <Stopper> In the present embodiment, as shown in Fig. 12, a stopper 73 protruding from the outer surface of the cover 24 is provided on the second arm 22. The stopper 73 includes a stopper main body 73A (see Fig. 10) fixed to the holding portion 70 and a damper 73B protruding from an end of the stopper main body 73A. When the second shaft 72 rotates excessively and the second attachment member 63 is about to hit the cover 24 of the second arm 22, the damper 73B of the stopper 73 abuts against the second block 64 of the second attachment member 63. Thereby, the collision between the cover 24 and the second attachment member 63 can be avoided. A pair of stoppers 73 are provided to prevent the second shaft 72 from over-rotating clockwise and counterclockwise.

[0065] <Coil spring> In this embodiment, instead of the stopper 73 described above, as shown in FIG. 13, a coil spring 74 may be provided. The coil spring 74 is disposed between the third clamp portion 150A and the fourth clamp portion 150B. Inside the coil spring 74, a cable 130 (second straight portion 130C) is disposed. One end portion 74A of the coil spring 74 is fixed to the holding portion 70. The other end portion 74B of the coil spring 74 is fixed to the fourth clamp portion 150B. When the second shaft 72 rotates with respect to the holding portion 70, the over-rotation of the second shaft 72 is regulated by the rigidity of the coil spring 74.

[0066] In the configuration where the second attachment member 63 may collide with the cover 24 due to excessive rotation of the second shaft 72 as described above, it is preferable to provide the stopper 73 or the coil spring 74. However, for example, when the third clamp portion 150A fixes the cable 130 with the sheath 33, the torsional rigidity of the second straight portion 130C is high, and there may be a case where the second shaft 72 does not rotate so that the second attachment member 63 collides with the cover 24. In such a case, it is not necessary to provide the stopper 73 or the coil spring 74.

[0067] [Effects of Embodiment 2] The robot 110 of Embodiment 2 further includes a hollow second shaft 72 that extends parallel to the first axis A1 and is rotatably supported by the second arm 22 about the fourth axis A4 parallel to the first axis A1. The cable 130 further includes a second straight portion 130C that is continuous with the end portion of the curved portion 30B on the second arm 22 side and extends parallel to the first axis A1. At least one clamp portion 50 includes a first holder 151 fixed to the second arm 22 and a third clamp portion 150A that is a clamp portion 50 for fixing the second straight portion 130C inside the second arm 22, and a first holder 51 fixed to the second shaft 72 and a fourth clamp portion 150B that is a clamp portion 50 for fixing the second straight portion 130C inside the second shaft 72. The second attachment member 63 is fixed to the second shaft 72.

[0068] With such a configuration, when the fourth clamping portion 150B rotates with respect to the third clamping portion 150A, it is easy to absorb the torsional stress generated in the cable 130 as the first arm 21 and the second arm 22 rotate in the second straight portion 130C. As a result, torsional stress is less likely to occur in the curved portion 30B, so it is possible to suppress the concentration of torsional stress and bending stress in the curved portion 30B and damage to the cable 130.

[0069] The robot 110 of the second embodiment further includes a cover 24 that covers the second arm 22. The cover 24 includes a stopper 73 that protrudes from the outer surface of the cover 24. The stopper 73 preferably regulates the rotation of the second shaft 72 with respect to the second arm 22 by contacting the second attachment member 63 at an angle equal to or greater than a preset angle.

[0070] With such a configuration, by providing the stopper 73, it is possible to suppress the excessive rotation of the second shaft 72 with respect to the second arm 22.

[0071] The robot 110 of the second embodiment further includes a coil spring 74. The second straight portion 130C is disposed inside the coil spring 74. One end 74A of the coil spring 74 is preferably fixed to the second arm 22 (holding portion 70), and the other end 74B of the coil spring 74 is fixed to the fourth clamping portion 150B.

[0072] With such a configuration, by providing the coil spring 74, it is possible to suppress the excessive rotation of the second shaft 72 with respect to the second arm 22.

[0073] [Embodiment 3] The third embodiment of the present disclosure will be described with reference to FIGS. 14 to 17. In the third embodiment, the configuration of the flexible tube 80 that covers the outside of the cable 230 is different from that of the first embodiment. Since the other configurations, operations, and effects are the same as those of the first embodiment, the same reference numerals as those of the first embodiment are given to the members equivalent to those of the first embodiment, and detailed descriptions are omitted.

[0074] As shown in FIG. 14, the robot 210 of the present embodiment includes a flexible tube 80 that covers the outside of a cable 230 disposed between a first attachment member 260 and a second attachment member 263. The flexible tube 80 is formed of a synthetic resin material that is easily elastically deformed. The end of the flexible tube 80 on the base 11 side is connected to the first block 261 of the first attachment member 260 via a first joint portion 81. The end of the flexible tube 80 on the second arm 22 side is connected to the second block 264 of the second attachment member 263 via a second joint portion 82. The flexible tube 80 is rotatable with respect to the first joint portion 81 and the second joint portion 82.

[0075] The first attachment member 260 includes a hollow first block 261 fixed to the first shaft 44, and a fifth clamp portion 250A fixed inside the first block 261. The second attachment member 263 includes a hollow second block 264 fixed to the stay 22A of the second arm 22, and a sixth clamp portion 250B fixed inside the second block 264. The fifth clamp portion 250A and the sixth clamp portion 250B can be configured in the same manner as the clamp portion 50 of the first embodiment.

[0076] As shown in FIG. 15, in addition to the composite cable 34 similar to the cable 30 of the first embodiment, the cable 230 may include a spare air tube 232 or the like. As shown in FIG. 17, it is preferable that the clamp portion 50 that fixes the composite cable 34 and the spare air tube 232 forms a recess 257 in which the inner wall of the substantially cylindrical clamp portion 50 is further recessed outward. Here, the recess 257 is provided in the second holder 52 of the clamp portion 50. Thereby, as shown in FIG. 16, the spare air tube 232 can be accommodated in the recess 257 of the clamp portion 50 (here, the first clamp portion 50A). Although not shown, the cable 230 may be a cable 230 not covered with the sheath 33, that is, a bare wiring unit 31, a single wire 31A, an air tube 32, or the like.

[0077] [Operation and Effect of the Third Embodiment] The robot 210 of Embodiment 3 further includes a flexible tube 80 that covers the outside of the cable 230, a first joint portion 81 that connects one end of the flexible tube 80 to the first attachment member 260, and a second joint portion 82 that connects the other end of the flexible tube 80 to the second attachment member 263. At least one clamp portion 50 includes a fifth clamp portion 250A and a sixth clamp portion 250B. The first attachment member 260 includes a hollow first block 261 fixed to the first shaft 44 and a fifth clamp portion 250A disposed inside the first block 261. The second attachment member 263 includes a hollow second block 264 fixed to the second arm 22 and a sixth clamp portion 250B disposed inside the second block 264.

[0078] According to such a configuration, since the cable 230 is covered with the flexible tube 80, the cleanliness, dustproofness, and waterproofness in the usage environment of the robot 210 can be improved.

[0079] [Embodiment 4] Embodiment 4 of the present disclosure will be described with reference to FIG. 18. The robot 310 of Embodiment 4 is configured to include a flexible tube 80 that covers the cable 330, a first joint portion 81, a second joint portion 82, etc., similar to Embodiment 3. However, in Embodiment 4, different from Embodiment 3, a second shaft 72, a holding portion 70, a second straight portion 130C, etc. (the same configuration as in Embodiment 2) for absorbing the torsional stress of the cable 330 are provided on the second arm 22 side. Regarding the same configurations, operations, and effects as those in Embodiments 1 to 3, the corresponding members are denoted by the same reference numerals, and detailed descriptions are omitted.

[0080] In Embodiment 4, since the second shaft 72 is rotatably supported on the second arm 22 side, the cleanliness, dustproofness, and drip-proofness in the usage environment of the robot 310 are inferior to those in Embodiment 3, but the effect of reducing the torsional stress applied to the curved portion 30B is superior to that in Embodiment 3.

[0081] [Embodiment 5] Embodiment 5 of the present disclosure will be described with reference to FIG. 19. The robot 410 of Embodiment 5 includes a base 11 and arms 20 (a first arm 21 and a second arm 22) similar to those of Embodiment 1. Hereinafter, for the same configurations, operations, and effects as those of Embodiment 1, the same reference numerals as those in Embodiment 1 are assigned to the members equivalent to those in Embodiment 1, and detailed descriptions thereof are omitted.

[0082] In the present embodiment, a cable 430 is spanned between the base 11 and the second arm 22. The cable 430 is curved in an inverted U shape. The cable 430 is covered with a flexible tube 80 from the outside. The end of the flexible tube 80 on the base 11 side is connected to a base-side shaft 440 via a first joint portion 81. The end of the flexible tube 80 on the second arm 22 side is connected to an arm-side shaft 441 via a second joint portion 82. The flexible tube 80 is rotatable with respect to the first joint portion 81 and the second joint portion 82.

[0083] A base-side shaft 440 is fixed to the upper part of the base 11. The base-side shaft 440 has a hollow cylindrical shape. A base-side clamp portion 450A is fixed inside the base-side shaft 440. The base-side clamp portion 450A fixes the end of the cable 430 on the base 11 side inside the base-side shaft 440.

[0084] An arm-side shaft 441 is fixed to the upper surface of the stay 22A of the second arm 22. The arm-side shaft 441 has a hollow cylindrical shape. An arm-side clamp portion 450B is fixed inside the arm-side shaft 441. The arm-side clamp portion 450B fixes the end of the cable 430 on the second arm 22 side inside the arm-side shaft 441.

[0085] The robot 410 of this embodiment includes a base - side clamp portion 450A and an arm - side clamp portion 450B as the clamp portion 50. The base - side clamp portion 450A and the arm - side clamp portion 450B can be configured in the same manner as the clamp portion 50 of Embodiment 1. Note that the concave portions 257 of Embodiment 3 may be provided in the base - side clamp portion 450A and the arm - side clamp portion 450B as necessary.

[0086] In this embodiment, different from Embodiment 3 and Embodiment 4, the hollow members that accommodate the cable 430 inside are not rotatably connected via a bearing. Therefore, compared with the configurations of Embodiment 3 and Embodiment 4, the cleanliness and dust - proof and waterproof properties in the usage environment of the robot 410 can be improved.

[0087] [Operation and Effect of Embodiment 5] The robot 410 of Embodiment 5 further includes a flexible tube 80 that covers the outside of the cable 430, a hollow base - side shaft 440 that is arranged outside the base 11 and fixed to the base 11, a hollow arm - side shaft 441 that is arranged outside the arm 20 and fixed to the arm 20, a first joint portion 81 that connects one end of the flexible tube 80 to the base - side shaft 440, and a second joint portion 82 that connects the other end of the flexible tube 80 to the arm - side shaft 441. At least one clamp portion 50 includes a base - side clamp portion 450A that is a clamp portion 50 arranged inside the base - side shaft 440 and an arm - side clamp portion 450B that is a clamp portion 50 arranged inside the arm - side shaft 441.

[0088] According to such a configuration, since the cable 430 is covered with the flexible tube 80, the cleanliness and dust - proof and waterproof properties in the usage environment of the robot 410 can be improved. In particular, in this embodiment, since the base - side shaft 440 and the arm - side shaft 441 to which the ends of the flexible tube 80 are connected do not include a rotating portion including a bearing, the cleanliness and dust - proof and waterproof properties can be improved more than those of Embodiment 3 and Embodiment 4. Also, by providing the clamp portion 50 inside the base-side shaft 440 and the arm-side shaft 441, it is not necessary to provide the clamp portion 50 inside the base 11 and the arm 20. Therefore, the clamp stability and clamp strength of the cable 430 can be enhanced without increasing the size of the base 11 and the arm 20.

[0089] [Other Embodiments] (1) In the above embodiment, the first holder 51 and the second holder 52 of at least one clamp portion 50 were semi-cylindrical, but the first holder and the second holder may have other shapes.

[0090] (2) In the above embodiment, bolt fastening was adopted as the method for fixing the clamp portion 50 to the mating member and for fixing the second holder 52 to the first holder 51, but methods other than bolt fastening may be used for fixing these members.

[0091] (3) In the above embodiment, the clamp rubber 35 was arranged between the cables 30, 130, 230, 330, 430 and the clamp portion 50, but the clamp rubber may be omitted.

[0092] (4) In the above embodiment, the scalar robots 10, 110, 210, 310, 410 are exemplified, but the technology of the present disclosure can also be applied to orthogonal robots, vertical articulated robots, etc.

[0093] (5) In Embodiment 1 and Embodiment 2, the capcons were used for the first attachment member 60 and the second attachment member 63, but other cable fixing portions may be used for the first attachment member and the second attachment member.

Description of Reference Numerals

[0094] 10, 110, 210, 310, 410: Robots 11: Base 11A: Insertion Hole 11B: Wiring Plug 20: Arm 21: First Arm 22: Second Arm 22A: Stay 23: Actuating Shaft 24: Cover 30, 130, 230, 330, 430: Cable 30A: First straight part 30B: Curved part 31: Wiring unit 31A: Single wire 32: Air tube 33: Sheath 34: Composite cable 35: Clamp rubber 40: Pipe member 41: Fastening hole 42: Bolt receiving hole 43: Bearing 44: First shaft 50: Clamp part 50A: First clamp part 50B: Second clamp part 51: First holder 52: Second holder 53: Positioning hole 54: Fastening hole 55: Insertion hole 56: Fastening hole 60, 260: First mounting member 61, 261: First block 62: First cable fixing part 63, 263: Second mounting member 64, 264: Second block 65: Second cable fixing part 70: Holding part 71: Bearing 72: Second shaft 73: Stopper 73A: Stopper body 73B: Damper 74: Coil spring 74A: One end 74B: The other end 80: Flexible tube 81: First joint part 82: Second joint part 130C: Second straight part 150A: Third clamp part 150B: Fourth clamp part 151: First holder 151A: Body part 151B: Extension part 152: Second holder 232: Spare air tube 250A: Fifth clamp part 250B: Sixth clamp part 257: Concave part 440: Base side shaft 441: Arm side shaft 450A: Base side clamp part 450B: Arm side clamp part A1: First axis A2: Second axis A3: Third axis A4: Fourth axis B1, B2, B3: Bolts

Claims

1. A base, an arm movably supported with respect to the base, a cable having one end disposed on the base side and the other end disposed on the arm side, and at least one clamp portion for fixing the cable, each of the at least one clamp portion including a first holder fixedly or rotatably supported with respect to the base or the arm, and a second holder fixed to the first holder while sandwiching the cable therebetween, a flexible tube covering the outside of the cable, a hollow base-side shaft disposed outside the base and fixedly or rotatably supported by the base, a hollow arm-side shaft disposed outside the arm and fixedly or rotatably supported by the arm, a first joint portion connecting one end of the flexible tube to the base-side shaft, and a second joint portion connecting the other end of the flexible tube to the arm-side shaft, wherein the at least one clamp portion includes a base-side clamp portion which is a clamp portion disposed inside the base-side shaft and an arm-side clamp portion which is a clamp portion disposed inside the arm-side shaft, the robot.

2. The arm includes a first arm rotatably supported with respect to the base about a first axis, and a second arm rotatably supported with respect to the first arm about a second axis parallel to the first axis. The robot according to claim 1.

4. A base, an arm movably supported with respect to the base, a cable having one end disposed on the base side and the other end disposed on the arm side, and at least one clamp portion for fixing the cable, each of the at least one clamp portion including a first holder fixedly or rotatably supported with respect to the base or the arm, and a second holder fixed to the first holder while sandwiching the cable therebetween, the arm including a first arm rotatably supported with respect to the base about a first axis, and a second arm rotatably supported with respect to the first arm about a second axis parallel to the first axis, a pipe member extending parallel to the first axis and fixed to the base, A hollow first shaft that extends parallel to the first axis and is supported by the pipe member so as to be rotatable about a third axis parallel to the first axis. A first attachment member that is fixed to the first shaft and fixes the cable. A second attachment member that is supported by the second arm so as to be fixed or rotatable and fixes the cable. The cable includes a first straight portion that extends parallel to the first axis and is arranged at the end on the base side, and a curved portion that extends from the end of the first straight portion on the side opposite to the base toward the second arm side. The at least one clamp portion includes a first clamp portion that is a clamp portion that includes the first holder fixed to the pipe member and fixes the first straight portion inside the pipe member, and a second clamp portion that is a clamp portion that includes the first holder fixed to the first shaft and fixes the first straight portion inside the first shaft. The first attachment member fixes the end of the curved portion on the base side. The second attachment member fixes the end of the curved portion on the second arm side. A robot.

5. In the extended state where the rotating end of the second arm is farthest from the third axis. At least one of the first attachment member and the second attachment member is not arranged between the first axis and the second axis in the extending direction of the first arm. The curved portion forms an acute angle with a plane perpendicular to the first axis and is led out from the first attachment member toward the second arm side, and forms an acute angle with a plane perpendicular to the first axis and is led out from the second attachment member toward the base side. The robot according to claim 4.

6. The robot further includes a hollow second shaft that extends parallel to the first axis and is supported by the second arm so as to be rotatable about a fourth axis parallel to the first axis. The cable further includes a second straight portion that continues from the end of the curved portion on the second arm side and extends parallel to the first axis. The at least one clamp portion includes a third clamp portion that is a clamp portion that includes the first holder fixed to the second arm and fixes the second straight portion inside the second arm, and a fourth clamp portion that is a clamp portion that includes the first holder fixed to the second shaft and fixes the second straight portion inside the second shaft. The robot according to claim 4 or claim 5, wherein the second mounting member is fixed to the second shaft.

7. Further comprising a cover that covers the second arm, The cover includes a stopper that protrudes from an outer surface of the cover, The robot according to claim 6, wherein the stopper abuts against the second mounting member to restrict the second shaft from rotating relative to the second arm by a preset angle or more.

8. Further comprising a coil spring, The second linear portion is disposed inside the coil spring, One end of the coil spring is fixed to the second arm, The robot according to claim 6, wherein the other end of the coil spring is fixed to the fourth clamping portion.

9. A flexible tube that covers the outside of the cable, A first joint portion that connects one end of the flexible tube to the first mounting member, Further comprising a second joint portion that connects the other end of the flexible tube to the second mounting member, The at least one clamping portion includes a fifth clamping portion and a sixth clamping portion, The first mounting member includes a hollow first block fixed to the first shaft and the fifth clamping portion disposed inside the first block, The robot according to any one of claims 4 to 8, wherein the second mounting member includes a hollow second block that is fixedly or rotatably supported with respect to the second arm, and the sixth clamping portion disposed inside the second block.

10. A base, An arm movably supported with respect to the base, At least one hollow member fixedly or rotatably supported with respect to the base or the arm, A cable having one end disposed on the base side and the other end disposed on the arm side, At least one clamping portion that fixes the cable, Each of the at least one clamping portions includes a first holder and a second holder that is fixed to the first holder while sandwiching the cable therebetween, The at least one hollow member covers the at least one clamping portion from the outer side in the radial direction of the cable, The robot, wherein the first holder of the at least one clamping portion is fixed to the at least one hollow member.

11. The arm includes a first arm rotatably supported about a first axis with respect to the base, and a second arm rotatably supported about a second axis parallel to the first axis with respect to the first arm. The robot according to claim 10.

13. A base, an arm movably supported with respect to the base, at least one hollow member fixedly or rotatably supported with respect to the base or the arm, a cable having one end disposed on the base side and the other end disposed on the arm side, and at least one clamp portion for fixing the cable. Each of the at least one clamp portion includes a first holder and a second holder fixed to the first holder while sandwiching the cable therebetween. The at least one hollow member covers the at least one clamp portion from the outside in the radial direction of the cable. The first holder of the at least one clamp portion is fixed to the at least one hollow member. The arm includes a first arm rotatably supported about a first axis with respect to the base, and a second arm rotatably supported about a second axis parallel to the first axis with respect to the first arm. A first attachment member, and a second attachment member. The at least one hollow member includes a pipe member extending parallel to the first axis and fixed to the base, and a hollow first shaft extending parallel to the first axis and rotatably supported by the pipe member about a third axis parallel to the first axis. The first attachment member is fixed to the first shaft and fixes the cable. The second attachment member is fixedly or rotatably supported with respect to the second arm and fixes the cable. The cable includes a first straight portion extending parallel to the first axis and disposed at an end on the base side, and a curved portion extending from an end of the first straight portion opposite to the base side toward the second arm side. The at least one clamp portion includes a first clamp portion that is a clamp portion for fixing the first straight portion inside the pipe member and includes the first holder fixed to the pipe member, and a second clamp portion that is a clamp portion for fixing the first straight portion inside the first shaft and includes the first holder fixed to the first shaft. The first attachment member fixes the end portion on the base side of the curved portion. The second attachment member fixes the end portion on the second arm side of the curved portion, the robot.

14. In the extended state where the rotating end of the second arm is farthest from the third axis, at least one of the first attachment member and the second attachment member is not disposed between the first axis and the second axis in the extending direction of the first arm, the curved portion forms an acute angle with respect to a plane perpendicular to the first axis and is led out from the first attachment member toward the second arm side, and forms an acute angle with respect to a plane perpendicular to the first axis and is led out from the second attachment member toward the base side, the robot according to claim 13.

15. The at least one hollow member includes a hollow second shaft that extends parallel to the first axis and is supported by the second arm so as to be rotatable about a fourth axis parallel to the first axis. The cable further includes a second straight portion that is connected to the end portion on the second arm side of the curved portion and extends parallel to the first axis. The at least one clamp portion includes a first holder fixed to the second shaft and a fourth clamp portion that is a clamp portion for fixing the second straight portion inside the second shaft. The end portion on the second arm side of the second straight portion is fixed to the second arm inside the second arm. The second attachment member is fixed to the second shaft, the robot according to claim 13 or claim 14.

16. The robot further includes a cover that covers the second arm. The cover includes a stopper that protrudes from the outer surface of the cover. The stopper abuts against the second attachment member to regulate the rotation of the second shaft with respect to the second arm by a preset angle or more, the robot according to claim 15.

17. The robot further includes a coil spring. The second straight portion is disposed inside the coil spring. One end of the coil spring is fixed to the second arm. The other end of the coil spring is fixed to the fourth clamp portion, the robot according to claim 15.

18. a flexible tube that covers the outside of the cable; a first joint portion that connects one end of the flexible tube to the first attachment member; a second joint portion that connects the other end of the flexible tube to the second attachment member. The at least one clamping part includes a fifth clamping part and a sixth clamping part. The at least one hollow member includes a first block and a second block. The first attachment member includes the hollow first block fixed to the first shaft and the fifth clamping part arranged inside the first block. The second attachment member includes the hollow second block supported to be fixed or rotatable with respect to the second arm and the sixth clamping part arranged inside the second block. The robot according to any one of claims 13 to 17.

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