Robot and linear body processing structure for rotary joint

Abstract

Provided is a linear body processing structure (1) for a rotary joint (J) provided with a first member (120) and a second member (130) that is supported relative to the first member (120) so as to be capable of rotating about a prescribed axis (B), wherein: the linear body processing structure (1) comprises a first fixing member (11) that fixes a linear body (10) to the first member (120) at an intermediate position in the longitudinal direction of the linear body (10), and a second fixing member (12) that fixes the linear body (10) to the second member (130) at another intermediate position in the longitudinal direction of the linear body (10); and the linear body (10) between the first fixing member (11) and the second fixing member (12) has extra length necessary for the operation of the rotary joint (J) and extends along the direction of the axis (B) at a position separated from the axis (B) in the radial direction.

Description

Striated processing structure of revolute joints and robots

[0001] The present disclosure relates to a filament processing structure for a rotary joint and a robot.

[0002] A wire body processing structure is known for a joint having a first wrist element and a second wrist element rotatably connected around a predetermined rotation axis, in which a wire body is inserted into a hollow hole whose central axis is the rotation axis (see, for example, Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2020-006450

[0004] In the case of a processing structure in which a wire is inserted through a hollow hole extending along the rotation axis as described above, the wire must be inserted into the narrow space inside the hollow hole from one side of the rotation axis, making assembly and maintenance difficult. Therefore, it is desired to improve the ease of wiring the wire to the rotary joint.

[0005] One aspect of the present disclosure is a wire body processing structure for a rotary joint that includes a first member and a second member that is rotatably supported on the first member about a predetermined axis, the wire body processing structure including a first fixing member that fixes a midpoint in the longitudinal direction of the wire body to the first member, and a second fixing member that fixes another midpoint in the longitudinal direction of the wire body to the second member, the wire body between the first fixing member and the second fixing member having excess length necessary for operation of the rotary joint and extending along the axial direction at a position radially spaced from the axis.

[0006] Fig. 1 is a partial side view showing a robot to which a wire member processing structure according to an embodiment of the present disclosure is applied. Fig. 2 is a schematic view showing a cross section of a portion of the robot of Fig. 1. Fig. 3 is a schematic view showing the shape of a wire member in a state where a first arm of the robot of Fig. 1 has rotated to a rearward limit angle. Fig. 4 is a schematic view showing the shape of a wire member in a state where a first arm of the robot of Fig. 1 has rotated to a forward limit angle. Fig. 5 is a side view showing a modified example of a wire member processing structure according to an embodiment of the present disclosure. Fig. 6 is a schematic view showing a cross section of a portion of a first modified example of the robot of Fig. 1. Fig. 7 is a schematic view showing a cross section of a portion of a second modified example of the robot of Fig. 1.

[0007] A wire member processing structure 1 of a robot 100 according to an embodiment of the present disclosure will be described below with reference to the drawings. The robot 100 to which the wire member processing structure 1 according to the present embodiment is applied is, for example, a six-axis vertical articulated robot.

[0008] 1 , the robot 100 includes a base 110 that is placed on a horizontal installation surface such as a floor, and a rotating body (first member) 120 that is rotatably supported relative to the base 110 about a vertical first axis A. The robot 100 also includes a first arm (second member) 130 that is rotatably supported relative to the rotating body 120 about a horizontal second axis B. The robot 100 also includes a second arm (not shown) that is rotatably supported relative to the tip of the first arm 130, and a three-axis wrist unit (not shown) attached to the tip of the second arm. In other words, the robot 100 has six rotational joints.

[0009] The base 110 is a box-shaped member having a hollow space 111 formed therein. A distribution board 112 is attached to one side of the base 110 (here, the side facing the rear of the robot 100). One end of an external cable 15 extending from an externally installed power supply device and control device (not shown) is connected to the distribution board 112. In addition, a through-hole 110h that includes the first axis A and extends along the first axis A is provided in the upper surface of the base 110.

[0010] The rotating body 120 is supported on the upper surface of the base 110 via a reducer (not shown) so as to be rotatable about a first axis A. The rotating body 120 includes a main body 121 having a through hole 120h that includes the first axis A and extends along the first axis A. As shown in FIG. 2 , the rotating body 120 also includes a pair of wall-shaped support members 122 and 123 that face each other parallel to each other and extend vertically upward on both sides of the through hole 120h of the main body 121 in the direction of the second axis B.

[0011] The support part 122 has a through hole 122h whose central axis is the second axis B. Furthermore, a motor 127 and a reducer 126 disposed between the motor 127 and the first arm 130 are fixed to an outer surface 122s of the support part 122. This allows the reducer 126 to reduce the rotation of the motor 127, thereby allowing the first arm 130 to rotate around the second axis B relative to the rotating body 120. The first arm 130 is supported by an output shaft 126a of the reducer 126 on the support part 122 side.

[0012] The support part 123 has a cylindrical pillar part 125 on the side facing the first arm 130, which extends in a direction toward the support part 122 with the second axis B as its central axis. The support part 123 also has a through-hole 123h that penetrates from the outer surface 123s of the support part 123 to the tip of the pillar part 125 along the second axis B.

[0013] 1, at least the outer peripheral surface of the support portion 123 on the diagonally upper front side with respect to the second axis B is formed into a cylindrical surface with a radius equal to that of the outer peripheral surface of the columnar portion 125. In the example shown in FIG. 1, the outer peripheral surface of the columnar portion 125 forms the outer peripheral surface of the support portion 123 over a range of approximately 180° from the front to the rear of the support portion 123. Furthermore, a plurality of screw holes (not shown) for fixing a first fixing member 11 (described later) are provided near an edge 123e on the diagonally upper front side of an outer surface 123s of the support portion 123.

[0014] 2, the first arm 130 is a long hollow member having an internal hollow portion 131. The first arm 130 is disposed between the pair of support portions 122, 123 with its longitudinal axis extending along a plane perpendicular to the second axis B.

[0015] A cylindrical surface is provided within hollow portion 131 of first arm 130, with the second axis B as its central axis and a radius equivalent to the radius of columnar portion 125. An opening 130h is formed in first arm 130 at a part of the circumferential direction of the cylindrical surface, penetrating wall surface 133 on the support portion 123 side in the thickness direction to open hollow portion 131 to the outside.

[0016] Furthermore, a plurality of screw holes (not shown) for fixing a second fixing member 12 (described later) are provided on the inner wall of the hollow portion 131 of the first arm 130 on the support portion 122 side. These screw holes are arranged at radial positions slightly radially outwardly away from the second axis B relative to the radial dimension of the columnar portion 125. Furthermore, when the longitudinal axis of the first arm 130 is in an orientation in which it extends vertically upward, these screw holes are arranged at the same circumferential positions around the second axis B as the plurality of screw holes for fixing the first fixing member 11 provided in the support portion 123.

[0017] Furthermore, a hole 130f is provided in the wall surface 133 of the first arm 130, extending from the wall surface 133 toward the wall surface 132 on the support portion 122 side with the second axis B as its central axis. As shown in FIG. 2 , the tip of a shaft 124 fitted into a through hole 123h of the support portion 123 from the outside in the direction of the second axis B is disposed within the hole 130f via a bearing. The shaft 124 is fixed to the support portion 123 with a plurality of bolts. As a result, the first arm 130 is supported by the shaft 124 on the support portion 123 side so as to be rotatable about the second axis B. In this manner, the first arm 130 is supported in a doubly supported beam-like manner by the pair of supports 122, 123 on both sides in the direction of the second axis B so as to be rotatable about the second axis B, thereby forming a rotary joint J.

[0018] The robot 100 includes a wire body 10 that is wired from a distribution board 112 on the base 110 to a wrist unit at the distal end via each of the six rotary joints. The wire body 10 transmits power and control signals from an external power supply and control device to the motors provided in each rotary joint of the robot 100.

[0019] 1 and 2, the wire body processing structure 1 according to this embodiment is a processing structure for a wire body 10 that is wired to a rotary joint J that includes a rotating body 120 and a first arm 130. The following description will be given taking as an example a position in which the longitudinal axis of the first arm 130 extends vertically upward, i.e., the first arm 130 is at the origin position. In this case, the base end of the wire body 10 is connected to the distribution board 112 within the hollow portion 111 of the base 110, and the tip end passes through the through holes 110h and 120h and is guided upward along the first axis A. After passing through the through hole 120h, the wire body 10 is bent toward the rear of the robot 100, then goes around the rear of the support portion 123, and is pulled outward in the direction of the second axis B.

[0020] The wire body 10 drawn outward in the direction of the second axis B is guided obliquely forward and upward along the outer surface 123s of the support portion 123 toward the second axis B. The wire body 10 is then fixed to the support portion 123 by the first fixing member 11. In this case, the first fixing member 11 is fixed to the support portion 123 by fastening bolts S1 into a plurality of screw holes provided near an edge 123e of the support portion 123. As a result, after crossing the second axis B, the wire body 10 is fixed to the support portion 123 at a midpoint in the longitudinal direction near the outer peripheral surface of the obliquely forward and upper edge 123e of the support portion 123.

[0021] Next, the portion of the wire body 10 distal to the position where it is fixed by the first fixing member 11 is bent approximately 90° toward the first arm 130, as shown in Fig. 2. The wire body 10 is then extended along the outer circumferential surface of the columnar portion 125 and is inserted into the hollow portion 131 through the opening 130h of the first arm 130. Thereafter, a midpoint of the wire body 10 in the longitudinal direction is fixed to the first arm 130 by the second fixing member 12. The second fixing member 12 is fixed to the first arm 130 by fastening bolts S2 into a plurality of screw holes provided in the inner wall of the hollow portion 131.

[0022] In this case, the second fixing member 12 is located far away from the first fixing member 11 in the direction of the second axis B, and is disposed at a position that is close to the first fixing member 11 in the radial and circumferential directions of the second axis B. As a result, the filament 10 between the first fixing member 11 and the second fixing member 12 extends along the direction of the second axis B in the space radially outside the outer circumferential surface of the columnar portion 125.

[0023] The operation of the wire body processing structure 1 according to this embodiment configured as described above will be described below. According to the wire body processing structure 1 of the robot 100 according to this embodiment, the first fixing member 11 and the second fixing member 12 are separated by a large distance in the direction of the second axis B. The wire body 10 is arranged along the columnar portion 125, which is positioned closer to the second axis B than the outer shape of the first arm 130. Therefore, the middle position of the wire body 10 in the longitudinal direction can be fixed to the first arm 130 at a position relatively close to the second axis B, and the movement distance of the second fixing member 12 accompanying the movement of the first arm 130 can be relatively short.

[0024] As a result, it is possible to ensure an excess length, which is a length of margin necessary to allow movement of the first arm 130, without significantly slackening the filament 10 between the first fixed member 11 and the second fixed member 12. In other words, even with a relatively small excess length, slack can be maintained in the filament 10 between the first fixed member 11 and the second fixed member 12 for rotation of the first arm 130 about the second axis B over the entire range of movement.

[0025] Furthermore, the wire 10 between the first fixing member 11 and the second fixing member 12 is routed outside the outer circumferential surface of the columnar portion 125. This allows for a larger space to be secured around the wire 10 compared to the conventional case in which the wire 10 is routed through a narrow space in a hollow hole formed at a position including the axis of the rotary joint. This therefore improves the workability of assembling and removing the wire 10.

[0026] Furthermore, since the filament 10 is disposed on the outside of the outer circumferential surface of the columnar portion 125, it is possible to flexibly accommodate an increase in the number or thickness of the assembled filament 10. That is, unlike the conventional processing structure in which the filament 10 is passed through a hollow hole, it is not necessary to enlarge the hollow hole or the size of the rotary joint in response to an increase in the number or thickness of the filament 10.

[0027] In this case, the wire 10 between the first fixed member 11 and the second fixed member 12 extends in the direction of the second axis B and is disposed near the second axis B, thereby ensuring the surplus length necessary for the operation of the first arm 130. As a result, even if the wire 10 between the first fixed member 11 and the second fixed member 12 is relatively long, it does not protrude significantly radially outward about the second axis B. Therefore, as shown in FIGS. 3 and 4 , even when the first arm 130 is rotated rearward or forward to its limiting angle, the surplus portion of the wire 10 can be accommodated inside an imaginary cylindrical surface C having the second axis B as its central axis and including the second fixed member 12. Therefore, within the movable range of the first arm 130 about the second axis B, the wire 10 between the first fixed member 11 and the second fixed member 12 can be prevented from swinging significantly and coming into contact with surrounding components, etc., which can be reduced.

[0028] In this embodiment, the first fixing member 11 fixes a midpoint in the longitudinal direction of the umbilical member 10 near the outer circumferential surface of the edge 123e of the support portion 123. That is, the portion of the umbilical member 10 that is distal to the first fixing member 11 is positioned outward from the outer circumferential surface of the edge 123e of the support portion 123. This prevents the umbilical member 10 between the first fixing member 11 and the second fixing member 12 from being pressed against the outer circumferential surface of the edge 123e when the first arm 130 is operated, thereby reducing the possibility of wear and damage to the umbilical member 10.

[0029] Furthermore, in this embodiment, the second fixed member 12 is disposed within the hollow portion 131 of the first arm 130. This allows the space in the direction of the second axis B of the rotary joint J to be efficiently utilized, and the first fixed member 11 and the second fixed member 12 to be separated significantly in the direction of the second axis B. Therefore, even if the rotary joint J is not made larger, a sufficient length of leeway can be provided for the filament 10 between the first fixed member 11 and the second fixed member 12.

[0030] In this embodiment, the first fixing member 11 fixes the filament 10 at a position coinciding with the edge 123e of the support portion 123. Alternatively, the first fixing member 11 may fix the filament 10 at a position intersecting the second axis B or at a position slightly rearward of the second axis B.

[0031] 5 , the first fixing member 11 may fix a portion of the filament 10 slightly closer to the base end than the portion intersecting with the second axis B. This allows a larger space to be secured on the outer surface 123s for fixing the first fixing member 11. In this case, for example, by attaching a relatively slippery, low-friction member T such as a tetrafluoroethylene seal to the edge 123e, damage to the portion of the filament 10 distal to the first fixing member 11 due to contact with the support portion 123 can be prevented.

[0032] In the present embodiment, the second fixing member 12 is fixed to the inner wall of the hollow portion 131 of the first arm 130. Alternatively, the second fixing member 12 may be attached to the wall surface 133 of the first arm 130. In this case, it is sufficient that the outer surface 123s of the support portion 123 and the wall surface 133 of the first arm 130 are separated from each other in the direction of the second axis B. This ensures a sufficient length of clearance for the umbilical cord 10 between the first fixing member 11 and the second fixing member 12. Furthermore, the second fixing member 12 can be attached to and detached from the first arm 130 outside the first arm 130, making it easier to attach and detach the second fixing member 12.

[0033] In addition, in this embodiment, the filament processing structure 1 was applied to the rotary joint J between the rotating body 120 and the first arm 130 of the robot 100, but it is not limited to this and may be applied to other rotary joints of the robot 100.

[0034] In addition, in the present embodiment, the umbilical member processing structure 1 is described as being applied to a six-axis vertical articulated robot 100, but the application of the umbilical member processing structure 1 is not limited to this. For example, the umbilical member processing structure 1 may be applied to any robot equipped with a rotary joint, such as a horizontal articulated robot. Alternatively, the umbilical member processing structure 1 may be applied to industrial machinery, such as an injection molding machine or machine tool, equipped with a rotary joint.

[0035] Furthermore, in the robot 100 according to this embodiment, the first arm 130 is supported in a cantilevered manner by the pair of supports 122, 123. Alternatively, if the first fixed member 11 can be positioned far away from the second fixed member 12 fixed to the first arm 130 in the direction of the second axis B, the support 123 may be omitted and the first arm 130 may be supported in a cantilevered manner.

[0036] Furthermore, the pillar-shaped portion 125 of the robot 100 according to this embodiment is provided on the support portion 123 of the rotating body 120. Alternatively, the pillar-shaped portion 125 may be provided on the wall surface 133 of the first arm 130 on the support portion 123 side.

[0037] For example, as shown in Fig. 6, the columnar portion 125 may protrude from a wall surface 133 of the first arm 130 toward the support portion 123. In this case, the tip of the shaft 124 fitted into a through hole 123h of the support portion 123 from the outside in the direction of the second axis B may be fitted into a hole 130f provided on the tip side of the columnar portion 125 with a bearing interposed therebetween. Alternatively, as shown in Fig. 7, the columnar portion 125 may be formed in a shape that protrudes from the inner wall of the hollow portion 131 of the first arm 130 outward in the direction of the second axis B beyond the wall surface 133.

[0038] Although the embodiments of the present disclosure have been described in detail above, the present disclosure is not limited to the individual embodiments described above. Various additions, substitutions, modifications, partial deletions, etc. are possible to these embodiments without departing from the gist of the invention or the concept and spirit of the present invention derived from the content of the claims and their equivalents. For example, in the above-described embodiments, the order of each operation and the order of each process are shown as examples and are not limited to these.

[0039] The following supplementary notes are further disclosed regarding the above-described embodiments and modified examples: (Supplementary Note 1) A wire member processing structure for a rotary joint including a first member and a second member supported rotatably about a predetermined axis relative to the first member, the structure including: a first fixing member that fixes a midpoint in the longitudinal direction of the wire member to the first member; and a second fixing member that fixes another midpoint in the longitudinal direction of the wire member to the second member, wherein the wire member between the first fixing member and the second fixing member has an excess length necessary for operation of the rotary joint and extends along the axial direction at a position radially spaced from the axis. (Supplementary Note 2) The wire body processing structure for a rotary joint according to Supplementary Note 1, wherein the first member comprises a pair of support parts that support the second member rotatably about the axis at positions sandwiching the second member from both sides in the axial direction, one of the support parts or a supported part of the second member supported by the one support part comprises a columnar part extending along the axis, the first fixed member is fixed to an outer surface of the one support part in the axial direction, and the wire body between the first fixed member and the second fixed member is arranged radially outward of the columnar parts. (Supplementary Note 3) The wire body processing structure for a rotary joint according to Supplementary Note 2, wherein the columnar part is cylindrical, and the first fixed member extends the midpoint of the wire body in a direction intersecting the axis and fixes the wire body at a radial position on the second fixed member side that is at least equivalent to the outer diameter of the columnar part. (Supplementary Note 4) A filament processing structure for a rotary joint according to any one of Supplementary Note 1 to Supplementary Note 3, wherein the second member is a hollow member having a hollow portion and an opening that opens the hollow portion to the first member side in the axial direction, and the second fixed member is fixed within the hollow portion.(Supplementary Note 5) A robot comprising: at least one rotary joint including a first member and a second member supported rotatably about a predetermined axis relative to the first member; a wire wired spanning the first member and the second member of the rotary joint; a first fixing member fixing a midpoint in the longitudinal direction of the wire wire to the first member; and a second fixing member fixing another midpoint in the longitudinal direction of the wire wire to the second member, wherein the wire wire between the first fixing member and the second fixing member has an excess length necessary for operation of the rotary joint and extends along the axial direction at a position radially spaced from the axis. (Supplementary Note 6) The robot according to Supplementary Note 5, wherein the first member is a swivel body supported rotatably about a first axis perpendicular to the installation surface with respect to a base placed on the installation surface, and the second member is an arm supported rotatably relative to the swivel body about a second axis extending along a plane perpendicular to the first axis.

[0040] REFERENCE SIGNS LIST 1 Wire body processing structure 10 Wire body 11 First fixed member 12 Second fixed member 100 Robot 110 Base 120 Rotating body (first member) 122, 123 Support portion 123s Outer surface 125 Column-shaped portion 130 First arm (second member) 130h Opening 131 Hollow portion A First axis B Second axis (axis) J Rotational joint

Claims

1. A wire processing structure for a rotary joint comprising a first member and a second member supported on the first member so as to be rotatable about a predetermined axis, the wire processing structure comprising: a first fixing member fixing a midpoint in the longitudinal direction of the wire to the first member; and a second fixing member fixing another midpoint in the longitudinal direction of the wire to the second member, the wire between the first fixing member and the second fixing member having a surplus length necessary for the operation of the rotary joint and extending along the axial direction at a position radially spaced from the axis.

2. A filament processing structure for a rotary joint as described in claim 1, wherein the first member has a pair of support parts that support the second member rotatably about the axis at a position sandwiching the second member from both sides in the axial direction, one of the support parts or a supported part of the second member supported by the one of the support parts has a columnar part extending along the axis, the first fixed member is fixed to the outer surface of the one of the support parts in the axial direction, and the filament between the first fixed member and the second fixed member is arranged radially outward of the columnar part.

3. A filament processing structure for a rotary joint as described in claim 2, wherein the columnar portion is cylindrical, and the first fixing member extends the intermediate position of the filament in a direction intersecting with the axis and fixes the filament at a radial position on the second fixing member side that is at least equivalent to the outer diameter of the columnar portion.

4. A wire processing structure for a rotary joint as described in any one of claims 1 to 3, wherein the second member is a hollow member having a hollow portion and an opening that opens the hollow portion to the first member side in the axial direction, and the second fixed member is fixed within the hollow portion.

5. A robot comprising: at least one rotary joint including a first member and a second member supported on the first member so as to be rotatable about a predetermined axis; a wire wired across the first member and the second member of the rotary joint; a first fixing member fixing a midpoint in the longitudinal direction of the wire wire to the first member; and a second fixing member fixing another midpoint in the longitudinal direction of the wire wire to the second member, wherein the wire wire between the first fixing member and the second fixing member has a surplus length necessary for the operation of the rotary joint and extends along the axial direction at a position radially spaced from the axis.

6. A robot as described in claim 5, wherein the first member is a rotating body supported rotatably about a first axis perpendicular to the installation surface with respect to a base placed on the installation surface, and the second member is an arm supported rotatably relative to the rotating body about a second axis extending along a plane perpendicular to the first axis.

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