Workpiece support device

Abstract

A workpiece support device (1) includes a base (2), a worktable (3) of an electrically conductive material rotatably supported by the base (2), a motor (4), a speed reducer (5) that reduces the rotation of the motor (4) and transmits the reduced rotation to the worktable (3), and a metal adapter that is interposed between the worktable (3) and the speed reducer (5) to separate the worktable (3) from the speed reducer (5), the worktable (3) and the adapter being electrically insulated by an insulating coating formed on a surface of the worktable (3) or the adapter by surface treatment.

Description

Technical Field

[0001] This invention relates to a workpiece support device. Background Technology

[0002] A known workpiece support device is a worktable that can rotatably support a workpiece welded by an arc welding robot (see, for example, Patent Document 1).

[0003] The worktable is made of a conductive material, and the electricity used for arc welding of the workpiece is supplied to the worktable via current collector brushes. To prevent welding current from flowing to the motor through the reducer, a resin insulating ring is sandwiched between the worktable and the reducer that drives the worktable.

[0004] In Patent Document 1, to ensure electrical insulation across the entire surface between the reducer shaft and the worktable fixed to the shaft, the insulating ring is formed as a ring plate with approximately the same size as the worktable. Furthermore, to prevent welding current from flowing along the thickness of the insulating ring, the insulating ring is also set to be relatively thick.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 2019-48310 Summary of the Invention

[0008] The problem the invention aims to solve

[0009] The larger the worktable, the larger the insulating ring. The larger the insulating ring is made of rigid and highly insulating resin, such as phenolic resin, the more difficult and costly it is to manufacture.

[0010] Therefore, it is desirable to achieve low-cost and more reliable electrical insulation between the worktable and the motor.

[0011] Solution for solving the problem

[0012] One aspect of the present invention is a workpiece support device comprising: a base; a conductive worktable rotatably supported on the base; a motor; a reducer that reduces the rotation of the motor and transmits it to the worktable; and a metal adapter sandwiched between the worktable and the reducer to separate the worktable from the reducer, wherein the worktable and the adapter are electrically insulated by an insulating coating formed on the surface of the worktable or the adapter by a surface treatment.

[0013] Based on the above configuration, insulation performance can be achieved and production costs can be reduced. Attached Figure Description

[0014] Figure 1 This is a side view of a workpiece support device according to an embodiment of the present invention.

[0015] Figure 2 It means Figure 1 A cross-sectional view of the workpiece support device (AA section).

[0016] Figure 3 It is a local representation Figure 1 An exploded longitudinal sectional view of the components of the workpiece support device.

[0017] Figure 4 yes Figure 2 A partial longitudinal sectional view of the workpiece support device.

[0018] Figure 5 It means Figure 1 A partial longitudinal sectional view of a modified example of a workpiece support device.

[0019] Figure 6 It means Figure 1 A partial longitudinal sectional view of another variation of the workpiece support device.

[0020] Figure 7 It means Figure 1 A partial longitudinal sectional view of another variation of the workpiece support device.

[0021] Figure 8 It means Figure 1 A partial longitudinal sectional view of another variation of the workpiece support device.

[0022] Explanation of reference numerals in the attached figures:

[0023] 1: Workpiece support device

[0024] 2: Base

[0025] 3: Workbench

[0026] 4: Motor

[0027] 5: Reducer

[0028] 6: Adapter

[0029] 9: Small gear (gear)

[0030] 13, 16: Flange surfaces

[0031] 14: Threaded hole

[0032] 17, 19: Bolt through holes (through holes)

[0033] 18: Countersunk hole

[0034] 18a: Support surface

[0035] 23: Bolt

[0036] 23a: Head

[0037] 24: Insulating gasket Detailed Implementation

[0038] Hereinafter, a workpiece support device 1 according to one embodiment of the present invention will be described with reference to the accompanying drawings.

[0039] like Figure 1 as well as Figure 2 As shown, the workpiece support device 1 of this embodiment includes: a base 2, which is disposed on the ground; a worktable 3, which is supported on the base 2 in a manner that allows it to rotate around a horizontal axis of rotation X; a motor 4; and a reducer 5, which reduces the rotation of the motor 4 and transmits it to the worktable 3. In addition, in this embodiment, an adapter 6 is disposed between the worktable 3 and the reducer 5.

[0040] The base 2 is equipped with a power supply device (not shown) that supplies welding power to the worktable 3. The base 2 is provided with a circular through hole 7 that extends along the rotation axis X in the region including the rotation axis X of the worktable 3.

[0041] Workbench 3 is made of a conductive material.

[0042] The motor 4 is fixed to the base 2, and a small gear (gear) 9 that meshes with the input gear 8 of the reducer 5 is fixed on the motor shaft 4a.

[0043] The reducer 5 has a fixed part 10 fixed to the base 2 and a movable part 11 supported on the fixed part 10 in a manner that allows it to rotate around the rotation axis X.

[0044] In this embodiment, the fixing part 10 is composed of a shaft disposed radially inward, and is fixed to the base 2 at one end face in the direction of the rotation axis X. The fixing part 10 is provided with a hollow hole 12 that passes through along the rotation axis X at a position consistent with the through hole 7 of the base 2.

[0045] Furthermore, the movable part 11 is composed of an annular housing arranged radially outward relative to the axis, and an annular flange surface 13 is provided on the surface side, which is composed of a plane orthogonal to the rotation axis X. A plurality of threaded holes 14 are provided circumferentially spaced on the flange surface 13, and the threaded holes 14 extend parallel to the rotation axis X and are used to fix the worktable 3.

[0046] The worktable 3 is configured as a circular plate covering the other end face of the rotation axis X direction of the fixed part 10 and the movable part 11. A through hole 15 is provided on the worktable 3 at the same position as the hollow hole 12 of the fixed part 10.

[0047] Thus, a space is formed in the region containing the rotation axis X, extending from the surface of the worktable 3 to the back side of the base 2. A cylindrical tube 50 inserted into this space is fixed to the worktable 3. Since the position of the space inside the tube 50 does not change even when the worktable 3 rotates around the rotation axis X, cables and the like can pass through the tube 50 and from the back side of the workpiece support device 1 to the surface side of the worktable 3.

[0048] Furthermore, the worktable 3 has an annular flange surface 16 on its back side, which is formed by a plane orthogonal to the rotation axis X. The worktable 3 has multiple bolt through holes (through holes) 17 at positions corresponding to the multiple threaded holes 14 of the movable part 11, extending from the surface side to the flange surface 16 on the back side. Each bolt through hole 17 has a countersunk hole 18 on its surface side to accommodate the head 23a of a bolt 23.

[0049] The adapter 6 has a certain thickness and is formed into an annular shape between the flange surface 13 of the movable part 11 of the reducer 5 and the flange surface 16 of the worktable 3.

[0050] The adapter 6 has multiple bolt through holes (through holes) 19 extending along the thickness direction at the same positions as the multiple threaded holes 14 of the movable part 11 and the multiple bolt through holes 17 of the worktable 3.

[0051] In this embodiment, the adapter 6 has an insulating coating formed by surface treatment on the entire surface of the substrate made of metal material, namely the entire outer peripheral surface, the entire inner peripheral surface, the entire two end surfaces in the thickness direction, and the inner surface of all bolt through holes 19. The insulating coating is formed, for example, by precipitating insulating particles through a known electrochemical reaction, and has high insulation performance.

[0052] The inner circumferential surface of the adapter 6 is radially positioned by engaging with the mating outer surface 20 of the movable part 11 of the reducer 5. Furthermore, the mating inner circumferential surface of the adapter 6 and the mating outer surface 20 of the movable part 11 are sealed by an O-ring 21 disposed between them, and the end face of the adapter 6 and the end face of the movable part 11 are sealed by an O-ring 25 disposed between them. The adapter 6 is designed with a simple shape to facilitate the use of an insulating film; additionally, to ensure insulation distance, a groove for the O-ring 21 is provided in the movable part 11.

[0053] The outer peripheral surface of the adapter 6 is radially positioned by engaging with the inner fitting surface 22 provided on the worktable 3. The adapter 6 engages with the inner fitting surface 22 of the worktable 3, engages with the outer fitting surface 20 of the movable part 11 of the reducer 5, and has its two end faces in the thickness direction in close contact with the flange surface 13 of the reducer 5 and the flange surface 16 of the worktable 3.

[0054] The length of the mating inner surface 22 of the worktable 3 is set to be sufficiently shorter than the thickness of the adapter 6, for example, 5 mm or more shorter. As a result, with the two end faces of the adapter 6 in the thickness direction in close contact with the flange surface 13 of the reducer 5 and the flange surface 16 of the worktable 3, the movable part 11 of the worktable 3 and the reducer 5 are positioned at least 5 mm apart.

[0055] Furthermore, by fastening the bolts 23, which are inserted from the surface side of the worktable 3 into the bolt through holes 17 and 19 of the worktable 3 and the adapter 6, to the threaded hole 14 of the movable part 11 of the reducer 5, the worktable 3 is fixed relative to the movable part 11 of the reducer 5 in a radial and rotational axis X direction.

[0056] like Figure 3 as well as Figure 4 As shown, an insulating washer 24 made of electrically insulating material is sandwiched between the support surface 18a of the countersunk hole 18 of the bolt through hole 17 on the workbench 3 and the head 23a of the bolt 23. Figure 3 In the middle, the thick dashed line represents the coating.

[0057] Furthermore, the bolt 23 is made of metal, and the portion 23c, excluding the threaded portion 23b under the head, is coated with a coating made of an electrically insulating material along its entire length. The boundary between the threaded portion 23b and the portion 23c excluding the threaded portion 23b is positioned within the bolt through hole 19 of the adapter 6 after the bolt 23 is tightened. The coating can be a paint or a thin film.

[0058] The function of the workpiece support device 1 configured as described below will be explained.

[0059] According to the workpiece support device 1 of this embodiment, the workpiece is fixed to the surface of the worktable 3. The worktable 3 is rotated around the rotation axis X by the operation of the motor 4 via the reducer, thereby changing the posture of the workpiece. Since welding power is supplied to the worktable 3 by a power supply device (not shown), the workpiece can be welded, for example, by making the welding current flow from the welding torch mounted at the front end of the robot, through the workpiece and the worktable 3.

[0060] In this case, an adapter 6 is disposed between the worktable 3 and the movable part 11 of the reducer 5, and an insulating film is formed on the surface of the adapter 6. As a result, electrical insulation is provided between the contact surfaces of the flange surface 16 and the inner fitting surface 22 of the worktable 3 and the adapter 6, and between the flange surface 13 and the outer fitting surface 20 of the reducer 5 and the adapter 6.

[0061] Furthermore, by tightening the bolt 23, which is inserted into the bolt through hole 17 of the worktable 3, into the threaded hole 14 of the movable part 11, the worktable 3 and the adapter 6 are jointly secured to the movable part 11 of the reducer 5. In this case, the head 23a of the bolt 23 and the worktable 3 are electrically insulated by an insulating washer 24 disposed between the head 23a of the bolt 23 and the support surface 18a of the countersunk hole 18.

[0062] Furthermore, although the lower portion 23c of the bolt head is positioned close to the inner surface of the bolt through hole 17 of the worktable 3, it is electrically insulated by a coating made of an electrically insulating material applied to the bolt 23. Similarly, although the lower portion 23c of the bolt head is also positioned close to the inner surface of the bolt through hole 19 of the adapter 6, it is electrically insulated by a coating made of an electrically insulating material applied to the bolt 23 and an insulating film applied to the inner surface of the adapter 6. While the length of the electrically insulating material applied to the bolt 23 may vary slightly, it is sufficient to accommodate it within the thickness of the adapter 6.

[0063] Because the coating on the head of bolt 23 is applied to the portion 23c other than the threaded portion 23b, when the boundary between the threaded portion 23b and the portion 23c other than the threaded portion 23b is located within the bolt through hole 19 of adapter 6, the uncoated threaded portion 23b approaches the inner surface of the bolt through hole 19. Since an insulating film is formed on the inner surface of the bolt through hole 19 of adapter 6, bolt 23 can be electrically insulated from adapter 6 even in the threaded portion 23b where the metal surface is exposed.

[0064] Furthermore, by adjusting the thickness of the adapter 6, the distance between the worktable 3 and the movable part 11 of the reducer 5 can be increased to more than 5mm, so that even if spatter accumulates, electrical conduction between the worktable 3 and the reducer 5 can be prevented.

[0065] Thus, the workpiece support device 1 of this embodiment does not use a large insulating ring made of insulating materials such as phenolic resin, which are difficult to manufacture and expensive. Instead, it uses an adapter 6 with an insulating film made of a metallic material. This has the advantages of achieving high insulation performance and significantly reducing production costs.

[0066] Furthermore, according to the workpiece support device 1 of this embodiment, in addition to the above-described configuration, such as... Figure 5 As shown, an insulating film can also be formed on the surface of the pinion 9 fixed to the motor shaft 4a of the motor 4 by the same surface treatment as that of the adapter 6. The insulating film can be provided on at least the entire outer surface of the pinion 9, and if the inner surface of the mating motor shaft 4a is also provided with an insulating film, more reliable insulation can be achieved.

[0067] In addition, such as Figure 5As shown, it can also be configured such that a thin sheet made of electrically insulating material is sandwiched between the motor 4 and the motor mounting surface of the base 2 used to fix the motor 4. Alternatively, an insulating film can be provided on the motor mounting surface. With this configuration, there is an advantage that even if welding current leaks from the worktable 3 to the reducer 5, the leaked welding current can be prevented from flowing to the motor 4 through the reducer 5.

[0068] In addition, in this embodiment, an insulating film is formed on the entire outer surface of the adapter 6 and the entire inner surface of the bolt through hole 19, but instead, as Figure 6 As shown, an insulating coating can also be formed on the flange surface 16 and the inner surface 22 of the worktable 3.

[0069] In addition, instead of forming an insulating film on the entire outer peripheral surface of the adapter 6 and the entire inner surface of the bolt through hole 19, such as Figure 7 As shown, an insulating film may also be applied only to the end face that contacts the flange surface 13 of the reducer 5 and the surface other than the inner surface of the bolt through hole 19.

[0070] In addition, in this embodiment, an electrically insulating coating is applied under the head of the bolt 23, but instead, as... Figure 8 As shown, ordinary bolts 23 without coating can also be used.

[0071] In this case, an insulating film can be formed inside the bolt through hole 17 of the workbench 3, or the inner diameter of the bolt through holes 17 and 19 can be increased to prevent the bolt 23 from contacting the inner surface of the bolt through holes 17 and 19.

[0072] In this embodiment, a countersunk hole 18 is provided on the surface side of the worktable 3, and the bolt 23 is fastened from the surface side of the worktable 3. This allows the worktable 3 to be easily removed by unloading the bolt 23 from the surface side, improving maintainability. Alternatively, the countersunk hole 18 can be provided on the back side of the reducer 5, and a threaded hole 14 can be provided on the worktable 3 side, where the bolt 23 inserted from the reducer 5 side is fastened to the threaded hole 14 of the worktable 3.

[0073] In addition, in this embodiment, a workpiece support device 1 with one axis that rotates the worktable 3 around a single rotation axis X is described as an example. However, it can also be applied to a workpiece support device 1 with two or more rotation axes X.

Claims

1. A workpiece support device, characterized in that, have: Base; A conductive worktable is supported on the base in a manner that allows it to rotate about a rotation axis; motor; A speed reducer that reduces the rotational speed of the motor and transmits the speed to the worktable; as well as A metal adapter, positioned further in the direction of the rotation axis than the end face of the movable part of the reducer where the worktable is fixed, is configured to engage with a fitting outer surface provided on the outer periphery of the movable part, and is clamped between the flange surface of the worktable and the flange surface of the movable part to separate the worktable from the reducer. The worktable and the adapter are electrically insulated by an insulating coating formed on the surface of the worktable or the adapter through a surface treatment.

2. The workpiece support device according to claim 1, characterized in that, The adapter is formed as an annular shape sandwiched between the annular flange surface of the reducer and the annular flange surface of the worktable. The insulating film is formed on the contact surface of the adapter with the workbench. The adapter has multiple through holes for multiple bolts to pass through, the bolts fastening the worktable and the reducer. The worktable and the reducer are fastened together by the bolts with electrically insulating washers inserted into them.

3. The workpiece support device according to claim 2, characterized in that, One of the workbench or the reducer is provided with a through hole for the bolt to pass through and a countersunk hole for the head of the bolt to be positioned. The workbench or the other of the reducers is provided with a threaded hole for fastening the bolt. The insulating washer is sandwiched between the support surface of the countersunk hole and the head of the bolt.

4. The workpiece support device according to claim 3, characterized in that, A coating or insulating film made of an electrically insulating material is applied to the outer peripheral surface of the bolt or the inner peripheral surface of the through hole of the adapter, which is configured in an inserted state in the worktable or the reducer.

5. The workpiece support device according to any one of claims 1 to 4, characterized in that, The motor is fixed to the base. The motor and the base are insulated from each other using an electrically insulating material.

6. The workpiece support device according to any one of claims 1 to 4, characterized in that, The motor and the reducer are equipped with gears that transmit the rotation of the motor. An insulating coating formed by surface treatment is provided on the surface of the gears in the motor.

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