Positioner

Abstract

A positioner (10) is provided with: a base (20) having a pair of support parts (21, 22) disposed at a predetermined interval in the direction of a first axis (A); a shaft member (30) disposed between the pair of support parts and supported so as to be rotatable about a first axis with respect to the base; and a disk-shaped rotary table (50) that is supported so as to be rotatable about a second axis (B) orthogonal to the first axis with respect to the shaft member and that has a mounting surface (51) on which a workpiece (W) can be mounted, the rotary table having an outer diameter dimension that is housed inside of both ends of the shaft member in the direction of the first axis and that is smaller than that of the shaft member in the direction of the second axis. In a movable range around the first axis of the rotary table, the distance between the carrying surface and the first axis is set to be larger than the distance between the outermost edge around the first axis of at least one supporting part and the first axis, and the distance between the back surface of the carrying surface of the rotary table and the first axis is set to be smaller than the distance between the outermost edge and the first axis.

Description

Technical Field

[0001] The present disclosure relates to a positioner. Background Art

[0002] There is known a rotary table device that rotates a supported workpiece about a tilt axis extending in the horizontal direction and about a rotation axis orthogonal to the tilt axis, and that can change the posture of the workpiece about the two axes (see, for example, Patent Document 1).

[0003] The rotary table device includes: a rotary table that fixes a workpiece and rotates the workpiece around a rotation axis; and a tilting table that supports the rotary table so as to be rotatable around the tilting axis.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Utility Model Application Laid-Open No. 06-000625 Summary of the invention

[0007] Problem that the invention aims to solve

[0008] When the surface of the rotary table is brought close to the tilt axis, the workpiece mounted on the rotary table may interfere with the surrounding components of the tilt table. Therefore, the size of the workpiece mounted on the rotary table is limited so as not to protrude too much from the rotary table.

[0009] On the other hand, the farther the rotary table is from the tilt axis, the greater the moment and inertia around the tilt axis.

[0010] Therefore, a positioner is desired that can suppress the moment and inertia generated when rotating a workpiece to be small without limiting the size of the workpiece.

[0011] Solutions for solving problems

[0012] One scheme of the present disclosure is a positioner, which comprises: a base having a pair of support parts arranged at a predetermined interval in a first axial direction; an axis component, which is arranged between the pair of support parts and is supported to be rotatable around the first axis relative to the base; and a circular plate-shaped rotating worktable, which is supported to be rotatable around a second axis orthogonal to the first axis relative to the axis component and has a mounting surface on which a workpiece can be mounted, the rotating worktable having the following outer diameter dimensions: it is accommodated on the inner side closer to the first axial direction than both ends of the axis component, and within the movable range of the rotating worktable around the first axis, the distance between the mounting surface and the first axis is set to be greater than the distance between the outermost edge of at least one of the support parts around the first axis and the first axis, and the distance between the back side of the mounting surface of the rotating worktable and the first axis is set to be less than the distance between the outermost edge and the first axis. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a perspective schematic diagram showing a positioner according to one embodiment of the present disclosure.

[0014] Figure 2 yes Figure 1 Longitudinal section view of the positioner.

[0015] Figure 3 yes Figure 1 Side view of the positioner.

[0016] Figure 4 Yes Figure 3 A side view of a state in which the shaft component of the positioner is rotated 90° around the first axis.

[0017] Figure 5 Viewed from the back side opposite to the rotary table Figure 1 Diagram of the shaft components of the positioner.

[0018] Figure 6 Yes means Figure 1 A longitudinal sectional view of a modified example of a positioner. DETAILED DESCRIPTION

[0019] Hereinafter, a positioner 10 according to an embodiment of the present disclosure will be described with reference to the drawings.

[0020] For example, Figure 1As shown, the positioner 10 of this embodiment includes a base 20 and a shaft member 30, the base 20 is set on a horizontal installation surface such as the ground, and the shaft member 30 is supported to be rotatable around a horizontal first axis A relative to the base 20. In addition, the positioner 10 includes a first drive mechanism 40, and the first drive mechanism 40 rotates the shaft member 30 around the first axis A relative to the base 20.

[0021] Furthermore, the positioner 10 further includes a rotary table 50 and a second drive mechanism 60. The rotary table 50 is supported to be rotatable relative to the shaft member 30 about a second axis B orthogonal to the first axis A. The second drive mechanism 60 drives the rotary table 50 to rotate. Figure 2 As shown, the positioner 10 includes a power cable 70 that connects the rotary table 50 and an external power supply device (not shown).

[0022] The base 20 includes a bottom 23 and flat plate-shaped support portions 21 and 22 . The bottom 23 is placed on a setting surface, and the flat plate-shaped support portions 21 and 22 protrude upward from the bottom 23 .

[0023] The support parts 21 and 22 are arranged in parallel with each other at a distance in the direction of the first axis A. Figure 3 As shown, the upper end surfaces of the support parts 21 and 22 have an outer shape of a cylindrical surface with the first axis A as the center axis.

[0024] In addition, if Figure 2 As shown, through holes 21h and 22h penetrating along the first axis A are respectively provided on the support parts 21 and 22 .

[0025] The base 20 includes sleeves 24 and 25 that are fitted into the through holes 21h and 22h, respectively. The sleeves 24 and 25 are provided with inner holes 24h and 25h, respectively.

[0026] like Figure 2 As shown, the shaft member 30 is a shaft-shaped member having a long axis, and includes end portions 31 and 32 on both sides in the long axis direction and a center portion 33 disposed between the end portions 31 and 32 .

[0027] The end portion 31 is supported so as to be rotatable about the first axis A relative to the sleeve 24. In addition, the end portion 32 is supported so as to be rotatable about the first axis A relative to the sleeve 25 by a first reducer (reducer) 42 to be described later installed between the end portion 32 and the sleeve 25. Thus, the shaft member 30 has its major axis along the first axis A and is supported between the support portions 21 and 22 in a two-beam shape.

[0028] For example, Figure 2As shown, the outer diameter dimensions of the end portions 31 and 32 around the first axis A are set larger than the outer diameter dimension of the center portion 33 around the first axis A. In addition, the end portion 31 is provided with a protrusion 34 formed by protruding a portion of the outer peripheral surface radially outward at a circumferential position along the second axis B. The front end surface of the protrusion 34 is located at the outermost edge of the shaft member 30 around the first axis A on the end portion 31 side.

[0029] In addition, when the shaft member 30 rotates around the first axis A beyond a predetermined angle, for example, beyond ±90°, from the position where the second axis B is arranged in the vertical direction, the protrusion 34 abuts against the stopper 26 provided on the support portion 21. Thus, the protrusion 34 and the stopper 26 limit the range of motion of the shaft member 30 to ±90°.

[0030] In addition, the end portion 31 is provided with a hollow portion (first hollow portion) 31h extending from the end surface along the first axis A. The sleeve 24 is inserted into the hollow portion 31h from the end surface side, and the bearing 11 is arranged between the outer peripheral surface of the sleeve 24 and the inner peripheral surface of the hollow portion 31h. Thus, the end portion 31 is supported so as to be rotatable around the first axis A relative to the sleeve 24.

[0031] In addition, the hollow portion 31h opens to the side opposite to the rotary table 50 (hereinafter also referred to as the back side) on the central portion 33 side relative to the portion supported by the bearing 11. Thus, a hollow path 35 is formed that passes from the outer side of the support portion 21 in the direction of the first axis A through the inner hole 24h of the sleeve 24 and the hollow portion 31h to the back side of the shaft member 30.

[0032] The center portion 33 has a shape that is recessed along the second axis B toward the first axis A, and has a cylindrical inner surface surrounding the second axis B.

[0033] The first drive mechanism 40 includes a first motor 41 fixed to the support portion 22 of the base 20, and a first speed reducer 42 that reduces the speed of rotation of a motor shaft 41a of the first motor 41 and transmits the rotation to the shaft member 30. The first motor 41 is fixed to the outer surface side of the sleeve 25 that is fitted into the through hole 22h of the support portion 22. The motor shaft 41a of the first motor 41 passes through the inner hole 25h of the sleeve 25 from the outside and is arranged along the first axis A.

[0034] The first speed reducer 42 includes a fixed portion 43 fixed to the inner surface side of the sleeve 25, and an output portion 44 that rotates relative to the fixed portion 43 around the first axis A. A plurality of gears (not shown) are accommodated inside the first speed reducer 42, and the plurality of gears (not shown) include a gear that meshes with the gear 45 fixed to the motor shaft 41a. The output portion 44 is fixed to the end surface of the end portion 32 of the shaft member 30. Thus, the rotation of the motor shaft 41a of the first motor 41 is decelerated by the first speed reducer 42 and transmitted to the end portion 32.

[0035] The outer peripheral surface of the output portion 44 is the outermost edge of the first reducer 42 around the first axis A on the end portion 32 side. In addition, the outer peripheral surface of the output portion 44 is arranged radially outside the first axis A as the center, relative to the upper end surfaces of the support portions 21 and 22 and the front end surface of the protrusion 34 of the shaft member 30.

[0036] That is, the outer peripheral surface of the output portion 44 is located at the outermost edge around the first axis A of the first speed reducer 42 , the shaft member 30 , and the base 20 .

[0037] The rotary table 50 is formed of a conductive material in a disk shape and has a mounting surface 51 for mounting the workpiece W. The rotary table 50 is disposed at a position where the central axis coincides with the second axis B and is supported by a second speed reducer 62 described later so as to be rotatable about the second axis B relative to the shaft member 30 .

[0038] In addition, if Figure 2 As shown, the outer diameter of the rotary table 50 is set to a size that allows it to be accommodated inside the ends 31 and 32 in the direction along the first axis A. That is, the rotary table 50 is arranged at a position that does not overlap with the ends 31 and 32 in the direction along the first axis A.

[0039] In addition, the distance between the mounting surface 51 of the rotary table 50 and the first axis A is set to be slightly larger than the outer diameter dimension of the outer peripheral surface of the output portion 44 .

[0040] On the other hand, Figure 3 as well as Figure 4 As shown, the distance between the back surface 52 of the rotary table 50 and the first axis A is set to be smaller than the outer diameter of the outer peripheral surface of the output portion 44 .

[0041] like Figure 5 As shown in FIG. 1 , the second drive mechanism 60 includes a second motor 61, and the second motor 61 is fixed to the shaft member 30 at a position offset in parallel with the second axis B. Figure 2As shown, the second drive mechanism 60 includes a second reducer 62, which reduces the rotation of the motor shaft (not shown) of the second motor 61 and transmits it to the rotary table 50. In addition, the second drive mechanism 60 includes a protective cover 65, which is fixed to the shaft member 30 and surrounds the second motor 61.

[0042] The second speed reducer 62 is disposed between the central portion 33 of the shaft member 30 and the rotary table 50. The second speed reducer 62 is fixed to the central portion 33, and reduces the rotation of the motor shaft of the second motor 61 and transmits it to the rotary table 50, thereby rotating the rotary table 50 around the second axis B relative to the shaft member 30.

[0043] In addition, a hollow portion (second hollow portion) 63 penetrating along the second axis B is provided in the central portion 33 of the rotary table 50, the second speed reducer 62, and the shaft member 30 in a region including the second axis B. One end of the hollow portion 63 in the direction of the second axis B is open on the mounting surface 51 side of the rotary table 50, and the other end is open on the back side of the shaft member 30.

[0044] like Figure 2 As shown, an adapter 55 made of a conductive material is fixed to the opening of the hollow portion 63 on the rotary table 50 side at a position blocking the opening so as to be detachable from the mounting surface 51 side. The adapter 55 is provided with a terminal 56 to which the power cable 70 is connected.

[0045] One end of the power cable 70 is connected to the terminal 56 of the adapter 55, and the other end is connected to the distribution box 71 provided on the side of the support portion 22. Thus, for example, the distribution box 71 is connected to an external welding power source (power supply device) not shown in the figure, so that the rotary table 50 is connected to the negative electrode via the power cable 70 and the adapter 55.

[0046] Hereinafter, the operation of the positioner 10 of the present embodiment configured in this manner will be described.

[0047] For example, when arc welding is performed on a workpiece W using a welding robot (not shown), the positioner 10 of this embodiment is first set at a predetermined position in the working area of ​​the welding robot. Then, the workpiece W is mounted on the mounting surface 51 of the rotary table 50 of the positioner 10 .

[0048] Next, the distribution box 71 fixed to the side of the support part 22 of the base 20 is connected to the external welding power source. As a result, the negative electrode is connected to the workpiece W via the power cable 70, the adapter 55 and the rotary table 50. In addition, the welding torch fixed to the front end of the wrist of the welding robot is connected to the positive electrode of the welding power source. Then, the front end of the welding torch is brought close to the surface of the workpiece W at a predetermined distance, and the welding robot is operated. As a result, an arc can be generated between the workpiece W and the welding torch to weld the workpiece W.

[0049] In this case, when the first motor 41 is operated, the rotation of the motor shaft 41a is decelerated by the first speed reducer 42 and transmitted to the shaft member 30. Thus, the shaft member 30 rotates about the first axis A relative to the base 20.

[0050] When the second motor 61 is operated, the rotation of the motor shaft of the second motor 61 is decelerated by the second speed reducer 62 and transmitted to the rotary table 50. As a result, the rotary table 50 rotates about the second axis B relative to the shaft member 30.

[0051] Thus, the posture of the workpiece W can be changed around the first axis A and around the second axis B. That is, the position of the surface of the workpiece W approached by the tip of the welding torch can be changed around two axes, so that a desired portion of the workpiece W can be welded.

[0052] In addition, in the present embodiment, the rotary table 50 is in a positional relationship that does not overlap with the end portions 31 and 32 of the shaft member 30 in the direction along the first axis A. Figure 3 As shown, in the rotary table 50 , a region near the central axis of the back surface 52 is closer to the first axis A than the outer peripheral surface of the output portion 44 .

[0053] That is, compared with the case where the entire rotary table 50 is arranged radially outward of the outer peripheral surface of the output portion 44 about the first axis A, the mounting surface 51 can be brought closer to the first axis A. Thus, the heavy workpiece W mounted on the mounting surface 51 can be arranged closer to the first axis A.

[0054] By bringing the workpiece W closer to the first axis A, the rotational moment and inertia acting on the rotary table 50 about the first axis A can be suppressed to be small when the shaft member 30 is rotated about the first axis A. As a result, the positioning accuracy of the workpiece W about the first axis A can be improved, and the load applied to the motor shaft 41a of the first motor 41 can be reduced.

[0055] In this case, if Figure 3 and Figure 4As shown, in the entire movable range of the rotary table 50 around the first axis A, the mounting surface 51 is always arranged radially outside the first axis A as centered on the outer peripheral surface of the output portion 44. That is, the first speed reducer 42, the shaft member 30, and the support portions 21 and 22 are not arranged on the moving path of the workpiece W placed on the mounting surface 51. As a result, when the posture of the workpiece W is changed around the first axis A, the workpiece W can be prevented from interfering with the components of the positioner 10.

[0056] Thus, according to the present embodiment, the workpiece W mounted on the rotary table 50 can be arranged at a position that does not interfere with the positioner 10 and is close to the first axis A. That is, the rotational torque and inertia when the workpiece W is rotated around the first axis A can be suppressed to be small without limiting the size of the workpiece W mounted on the rotary table 50.

[0057] In addition, if Figure 2 As shown, the power cable 70 of this embodiment is guided from the distribution box 71, for example, along the bottom 23 of the base 20 toward the outside of the support portion 21. Then, after being fixed to the support portion 21 by the first clamping member 81 at a position bent upward along the support portion 21, it is introduced into the hollow path 35 from the outside of the support portion 21.

[0058] The power cable 70 introduced into the hollow path 35 extends along the first axis A near the first axis A in the hollow path 35 , and is fixed to the shaft member 30 by the second clamp member 82 at a position after passing through the hollow portion 31 h of the shaft member 30 .

[0059] The power cable 70 then bends about 180 degrees in a U-shape after being bent away from the rotary table 50. The power cable 70 then extends along the second axis B and is introduced into the hollow portion 63. One end of the power cable 70 is detachably fixed to the terminal 56 provided on the adapter 55.

[0060] In this case, when the shaft member 30 is rotated relative to the base 20 about the first axis A, the relative positions of the first clamping member 81 and the second clamping member 82 about the first axis A change in accordance with the rotation. Therefore, the power cable 70 between the first clamping member 81 and the second clamping member 82 is twisted about the first axis A as it is bent and deformed about the first axis A. On the other hand, the power cable 70 between the second clamping member 82 and the terminal 56 is not deformed because it rotates about the first axis A as a whole with the shaft member 30.

[0061] When the rotary table 50 is rotated about the second axis B relative to the shaft member 30, a force in a torsional direction about the second axis B acts on the power cable 70. Therefore, torsional deformation and bending deformation occur about the second axis B in the U-shaped surplus length of the power cable 70 provided between the second clamping member 82 and the terminal 56.

[0062] Furthermore, the twisting force about the second axis B acting on the power cable 70 due to the rotation of the rotary table 50 about the second axis B is blocked by the second clamp member 82. Therefore, the power cable 70 closer to the first clamp member 81 than the second clamp member 82 is not deformed.

[0063] By routing the cables in this way, the two portions of the power cable 70 that are deformed by the rotation of the shaft member 30 about the first axis A and the portion that is deformed by the rotation of the rotary table 50 about the second axis B can be made different.

[0064] Thus, even when the shaft member 30 rotates about the first axis A and the rotary table 50 rotates about the second axis B simultaneously, the movements of the power cable 70 can be prevented from being combined and greatly disturbed.

[0065] Furthermore, when the shaft member 30 and the rotary table 50 are rotated about their respective axes, the power cable 70 can be deformed not only in torsion but also in bending. This also has the advantage that the force acting on the power cable 70 in the torsion direction can be effectively absorbed.

[0066] In the present embodiment, the power cable 70 between the second clamping member 82 and the terminal 56 is deformed as the rotary table 50 rotates about the second axis B. Alternatively, the power cable 70 may be maintained in its original position even when the rotary table 50 rotates about the second axis B.

[0067] For example, Figure 6 As shown, an adapter 55 is mounted on the rotary table 50, and a cylindrical shaft 57 and a rotary joint 58 are mounted on the adapter 55. The shaft 57 is formed of a conductive material, and the rotary joint 58 is mounted on the shaft 57. In addition, on the back side of the central portion 33 of the shaft member 30, a collector brush 90 is mounted at two locations spaced apart in the circumferential direction around the second axis B.

[0068] The collector brush 90 includes a brush portion 91 made of carbon and a pressing portion 92, and the pressing portion 92 presses the brush portion 91 against the outer peripheral surface of the shaft 57. Furthermore, by fixing the pressing portion 92 to the back surface of the central portion 33, the pair of brush portions 91 clamps the outer peripheral surface of the shaft 57 from the radial outside. In this case, the front end of the power cable 70 is connected to a terminal (not shown) provided on the pair of brush portions 91.

[0069] In this structure, when the rotary table 50 is rotated about the second axis B, the shaft 57 also rotates together with the rotary table 50 about the second axis B. On the other hand, the collector brush 90 does not rotate about the second axis B, and the brush portion 91 maintains contact with the outer peripheral surface of the shaft 57 .

[0070] Therefore, even if the rotary table 50 rotates infinitely around the second axis B, the rotary table 50 can continue to be connected to the negative electrode while maintaining the posture of the power cable 70. In addition, when the shaft member 30 rotates around the first axis A, only the portion of the power cable 70 between the first clamping member 81 and the second clamping member 82 is deformed, and the power cable 70 from the second clamping member 82 to the front end side is not deformed.

[0071] Thereby, the extra length of the power cable 70 provided on the front end side of the second clamp member 82 can be minimized, and the power cable 70 can be shortened and the positioner 10 as a whole can be minimised.

[0072] In the present embodiment, the outer peripheral surface of the output portion 44 of the first speed reducer 42 is the outermost edge of the positioner 10 around the first axis A in the movable range of the rotary table 50. Alternatively, other components may be arranged at the outermost edge of the positioner 10 around the first axis A.

[0073] For example, the protrusion 34 provided on the end portion 31 of the shaft member 30 may protrude radially outward about the first axis A rather than the outer peripheral surface of the output portion 44 .

[0074] In this case, since the front end surface of the protrusion 34 is the outermost edge around the first axis A of the positioner 10 , the mounting surface 51 only needs to be arranged slightly radially outside the front end surface of the protrusion 34 .

[0075] Thus, similarly to the above, it is possible to suppress the rotation moment and inertia around the first axis A to be small without limiting the size of the workpiece W mounted on the rotary table 50 .

[0076] Similarly, the upper end surfaces of the support portions 21 and 22 may be arranged radially outward of the outer peripheral surface of the output portion 44 and the front end surface of the protrusion 34 with respect to the first axis A. In this case, the mounting surface 51 only needs to be arranged slightly radially outward of the first axis A with respect to the upper end surfaces of the support portions 21 and 22.

[0077] In this case, the upper end surfaces of the support parts 21 and 22 may be formed into an outer surface shape of a half-circumference of a cylindrical surface having the first axis A as the center axis and a radius slightly shorter than the distance from the first axis A to the mounting surface 51 .

[0078] In the present embodiment, an adapter member having a larger diameter than the rotary table 50 may be positioned between the mounting surface 51 of the rotary table 50 and the workpiece W. Thus, the workpiece W can be supported by a surface wider than the mounting surface 51 of the rotary table 50 .

[0079] Furthermore, the positioner 10 of the present embodiment includes the power cable 70 connecting the negative electrode and the rotary table 50 , but in addition thereto, it may include a pipe for supplying a fluid such as pressurized air to the rotary table 50 side.

[0080] In this case, the pipe for supplying the fluid to the rotary table 50 may be laid along the same path as the power cable 70. In addition, the pipe may be fixed together with the power cable 70 by the first clamp member 81 and the second clamp member 82.

[0081] In summary, the embodiments of the present disclosure are described in detail, but the present disclosure is not limited to the above-mentioned embodiments. In these embodiments, various additions, substitutions, changes, partial deletions, etc. can be made without departing from the scope of the main purpose of the invention, or without departing from the concept and purpose of the present invention derived from the contents recorded in the claims and their equivalents. For example, in the above-mentioned embodiments, the order of each action and the order of each process are shown as an example, and are not limited to this.

[0082] Description of reference numerals:

[0083] 10: Positioner

[0084] 20: Base

[0085] 21: Support

[0086] 21h: Through hole

[0087] 22: Supporting part

[0088] 22h: Through hole

[0089] 30: Shaft components

[0090] 31h: Hollow part (first hollow part)

[0091] 42: First reducer (reducer)

[0092] 50: Rotating table

[0093] 51: Mounting surface

[0094] 52: Back

[0095] 62: Second reducer

[0096] 63: Hollow part (second hollow part)

[0097] 70: Power cable

[0098] 81: First clamping part

[0099] 82: Second clamping member

[0100] A: First axis

[0101] B: Second axis

[0102] W: Workpiece

Claims

1. A positioner, characterized in that: have: A base having a pair of support portions arranged at a predetermined interval in a first axial direction; a shaft member disposed between the pair of support portions and supported so as to be rotatable about the first axis relative to the base; as well as a disk-shaped rotary table supported so as to be rotatable relative to the shaft member about a second axis orthogonal to the first axis and having a mounting surface on which a workpiece can be mounted, The rotary table has an outer diameter dimension such that it is accommodated inside the two ends of the shaft member in the first axial direction. Within the movable range of the rotating worktable around the first axis, the distance between the mounting surface and the first axis is set to be greater than the distance between the outermost edge of at least one of the supporting parts around the first axis and the first axis, and the distance between the back side of the mounting surface of the rotating worktable and the first axis is set to be less than the distance between the outermost edge and the first axis.

2. The positioner according to claim 1, characterized in that: A speed reducer is provided between one of the support portions and one end portion of the shaft member, the speed reducer supporting the shaft member so as to be rotatable around the first axis relative to the support portion. The distance between the outer surfaces of the shaft component and the reducer in the direction of the second axis and the first axis is set to be smaller than the distance between the mounting surface and the first axis, and the distance between the back surface and the first axis is set to be smaller than the distance between the outer surface and the first axis.

3. The positioner according to claim 1 or 2, characterized in that: A portion of an outer peripheral surface of at least one of the support portions around the first axis is formed by a cylindrical surface around the first axis.

4. The positioner according to claim 1 or 2, characterized in that: The positioner has: a power cable connecting the rotary table with an external power supply device; and a second speed reducer, which connects the shaft component and the rotary table so as to be relatively rotatable about the second axis, The support portion on one side has a through hole penetrating along the first axis. The shaft member includes a first hollow portion communicating with the through hole. The second reducer includes a second hollow portion extending along the second axis. The power cable is guided toward the first axis along the support portion on one side, and is fixed to the outer surface of the support portion on one side by a first clamping component, and is introduced into the first hollow portion through the through hole. At a position bent away from the rotating worktable, the power cable is fixed to the shaft component by a second clamping component, and then bent with excess length, passes through the second hollow portion along the second axis, and one end is connected to the rotating worktable.

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