Brackets, robots, welding equipment and robot systems

Abstract

The present invention provides a bracket that comprises a bracket body (4) that is to be attached to a tool attachment surface (2a) of an arm member with an insulating plate (9) therebetween, an insulation member that electrically insulates the bracket body (4) and a bracket fixing implement that fixes the bracket body (4) to the tool attachment surface (2a) from the inside, and an insulating cover (10) that is arranged inside the bracket body (4) and has electrical insulation properties. The bracket body (4), the insulating plate (9), and the insulating cover (10) have hollow holes (41a, 9a, 10c) through which a linear body (A) is passed from within the arm member to the interior of the bracket body (4). The bracket fixing implement comprises a bolt (5) that is fastened into a screw hole (2c) in the tool attachment surface (2a). The insulating cover (10) covers a gap between the hollow hole (41a) in the bracket body (4) and the linear body (A) and is fixed to the bracket body (4) by the bolt (5).

Description

[Technical Field]

[0001] The present invention relates to a bracket, a robot, a welding device, and a robot system. [Background technology]

[0002] Industrial robots used for welding and the like are provided with an insulating structure that electrically insulates the tool from the robot body to prevent current from flowing from the tool into the robot body (see, for example, Patent Documents 1 to 3). In Patent Document 1, an insulating member is placed between the robot body and the tool. In Patent Documents 2 and 3, a disk-shaped insulating member is placed between the reducer at the tip of the robot body and the wrist flange, and an insulating washer and insulating collar are placed between the wrist flange and the bolt that secures the wrist flange to the robot body.

[0003] On the other hand, when attaching a tool to the tool mounting surface of a hollow arm member, a bracket with a hollow structure is sometimes used (see, for example, Patent Documents 4 and 5). The tool mounting surface of the hollow arm member has an opening for drawing out the wire from inside the arm member. If a non-hollow tool mounting surface is directly attached to the tool mounting surface, the opening is blocked by the tool, making it impossible to draw out the wire. By using a bracket with a hollow structure, it becomes possible to attach a non-hollow tool to the tool mounting surface. In other words, the non-hollow tool is attached to the tool mounting surface via the bracket, and the wire is routed from the opening through the bracket to the tool. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 62-142083 [Patent Document 2] Japanese Patent Application Laid-Open No. 2013-202697 [Patent Document 3] Japanese Patent Application Publication No. 11-114873 [Patent Document 4] Patent No. 5344315 [Patent Document 5] Japanese Patent Application Publication No. 08-047886 Summary of the Invention [Problem to be solved by the invention]

[0005] The bracket has a hollow hole that communicates with the hollow portion of the arm member and through which the umbilical member passes into the bracket, and the hollow portion of the arm member is exposed to the internal space of the bracket through the hollow hole of the bracket. Also, metal parts such as bolts that secure the bracket to the robot body may be placed inside the bracket. The internal space of the bracket is open to the outside so that the wire can be pulled out from inside the bracket to the outside. Therefore, it is desirable to prevent foreign matter, such as spatter, which has electrical insulation properties lower than air, from entering the bracket from the outside to the inside and adhering to the parts inside the bracket or the hollow portion of the arm member, thereby causing a decrease in electrical insulation between the bracket and the robot main body. [Means for solving the problem]

[0006] One aspect of the present disclosure is a bracket comprising: a hollow bracket body that is attached to the tool mounting surface of a hollow arm member with an electrically insulating plate interposed therebetween; an insulating member that electrically insulates the bracket body from a bracket fastener that fixes the bracket body to the tool mounting surface from the inside of the bracket body; and an electrically insulating insulating cover that is placed on the inside of the bracket body; the bracket body, the insulating plate, and the insulating cover each have a hollow hole through which a wire can pass from inside the arm member to the inside of the bracket body via an opening in the tool mounting surface; the bracket fastener includes one or more bolts that pass through through holes in the bracket body, the insulating plate, and the insulating cover and are fastened to screw holes in the tool mounting surface; the insulating cover covers a gap between the hollow hole in the bracket body and the wire, and is fixed to the bracket body by fastening the bolts. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is an overall configuration diagram of a robot according to an embodiment of the present disclosure. FIG. [Figure 2] FIG. 1 is a side view of a bracket according to an embodiment of the present disclosure attached to a tool mounting surface of a robot body. [Figure 3] FIG. 3 is a vertical cross-sectional view showing a bracket body of the bracket of FIG. 2. [Figure 4] FIG. 3 is a cross-sectional view of the bracket taken along line II in FIG. 2. [Figure 5] FIG. 5 is a partial vertical cross-sectional view of the bracket taken along line II-II in FIG. 4. [Figure 6] FIG. 10 is a partial vertical cross-sectional view showing a modified example of the bracket. [Figure 7] FIG. 10 is a partial vertical cross-sectional view showing another modified example of the bracket. [Figure 8] FIG. 10 is a partial vertical cross-sectional view showing another modified example of the bracket. [Figure 9] FIG. 10 is a partial vertical cross-sectional view showing another modified example of the bracket. [Figure 10]FIG. 10 is a partial vertical cross-sectional view showing another modified example of the bracket. [Figure 11] FIG. 10 is a partial vertical cross-sectional view showing another modified example of the bracket. [Figure 12] FIG. 10 is a partial vertical cross-sectional view showing another modified example of the bracket. [Figure 13] FIG. 10 is a partial vertical cross-sectional view showing another modified example of the bracket. [Figure 14] FIG. 14 is a front view of a clamp provided on the bracket of FIG. 13. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, a bracket 1, a robot 20, a welding device, and a robot system according to an embodiment of the present disclosure will be described with reference to the drawings. As shown in FIG. 1, the robot 20 is an industrial robot that includes a robot body 2 and a bracket 1 with a hollow structure that can be attached to a tool attachment surface 2 a of the robot body 2 .

[0009] The robot body 2 has at least one arm member. The tip surface of the most distal arm member 2b of the robot body 2 is a tool mounting surface 2a to which a tool 3 or a bracket 1 is attached. The tool mounting surface 2a is provided with a plurality of screw holes 2c (see FIG. 5) for bolts (bracket fixing devices) 5 that fix the tool 3 or the bracket 1 to the tool mounting surface 2a.

[0010] The most distal arm member 2b is hollow, and a hollow section 2d (see FIG. 5) within the arm member 2b opens onto the tool mounting surface 2a. For example, if the robot main body 2 is a six-axis vertical articulated robot, the arm member 2b is a cylindrical member that rotates around the sixth axis. A wire A that supplies power, signals, etc. to the tool 3 is wired within the hollow section 2d, and the wire A is drawn out to the outside of the arm member 2b from the opening on the tool mounting surface 2a.

[0011] If a tool 3 with a solid structure is directly attached to the tool attachment surface 2a, the opening of the hollow portion 2d will be blocked by the tool 3, making it impossible to pull out the filament A from the hollow portion 2d. Therefore, a tool 3 with a solid structure cannot be directly attached to the tool attachment surface 2a. The bracket 1 is intended to enable a tool 3 with a solid structure to be attached to the tool attachment surface 2a. The bracket 1 may be provided as part of a robot system including the robot 20 and the tool 3.

[0012] As shown in FIGS. 2 to 5, the bracket 1 includes a bracket body 4 fixed to the tool mounting surface 2a by a bracket fixing tool, an insulating member, an insulating cover 10, and a collar 11. As shown in Figure 3, the bracket main body 4 is a hollow box-shaped member made of a conductive metal material, and has a flat base end wall 41 and a flat tip wall 42 arranged parallel to each other with a gap between them, and a cylindrical side wall 43 connecting the base end wall 41 and the tip wall 42.

[0013] A robot mounting surface 4a is provided on the outer surface of the base end wall 41. The robot mounting surface 4a is fixed to the tool mounting surface 2a of the arm member 2b via an electrically insulating plate 9. A tool mounting surface 4b for mounting a tool 3 is provided on the outer surface of the tip end wall 42, which is arranged on the opposite side to the tool mounting surface 2a.

[0014] The base end wall 41 has a hollow hole 41a penetrating through the base end wall 41 in the thickness direction at a position facing the opening of the hollow portion 2d when the bracket body 4 is attached to the tool attachment surface 2a of the arm member 2b. The base end wall 41 also has a plurality of through holes 41b penetrating through the base end wall 41 in the thickness direction around the hollow hole 41a.

[0015] Each through hole 41b is provided at a position corresponding to a screw hole 2c on the tool mounting surface 2a when the bracket main body 4 is attached to the tool mounting surface 2a of the arm member 2b. A counterbore 12 is provided in each through hole 41b from the inner surface of the bracket main body 4 to a predetermined depth.

[0016] The insulating plate 9 is formed in the shape of an annular plate, and as shown in Fig. 5, when placed on the tool mounting surface 2a of the arm member 2b, has a hollow hole 9a that penetrates through the plate in the thickness direction at a central position facing the opening of the hollow portion 2d. The insulating plate 9 also has a plurality of through holes 9b that penetrate through the plate in the thickness direction around the hollow hole 9a. The through holes 9b are provided at positions that correspond to the screw holes 2c when the insulating plate 9 is placed on the tool mounting surface 2a of the arm member 2b.

[0017] As a result, when the bracket main body 4 is attached to the tool mounting surface 2a of the arm member 2b with the insulating plate 9 sandwiched therebetween, the hollow portion 2d of the arm member 2b communicates with the internal space of the bracket main body 4 via the hollow holes 9a, 41a. The wire A is wired from the opening of the hollow portion 2d through the hollow holes 9a, 41a to the inside of the bracket main body 4. The insulating plate 9 may be provided as part of the robot main body 2 or as part of the bracket 1.

[0018] The tip wall 42 may have a window 42a that penetrates the tip wall 42 in the thickness direction and through which the filament A can pass, and a screw hole 42b for fixing the tool 3. When the tool 3 has a hollow structure, the filament A is connected to the tool 3 attached to the tool attachment surface 4b via the window 42a.

[0019] The side wall 43 has at least one window 43a that penetrates the side wall 43 in the thickness direction and allows the passage of the filament A. When the tool 3 does not have a hollow structure, the filament A is drawn out to the outside of the bracket 1 through the window 43a and connected to the tool 3.

[0020] The bracket fixture includes a plurality of bolts 5 that are fastened to the threaded holes 2c in the tool mounting surface 2a. If necessary, the bracket fixture may include a metal washer 6 that is used together with each bolt 5. The bolts 5 and the metal washer 6 are made of a high-strength material, for example, steel.

[0021] The insulating member is made of an electrically insulating material such as resin and includes a cylindrical insulating sleeve 7 and an annular plate-shaped insulating washer 8. The insulating sleeve 7 and the insulating washer 8 each have an inner hole through which the bolt 5 passes.

[0022] The insulating sleeve 7 covers the outer circumferential surface of the bolt 5 located between the insulating washer 8 and the insulating plate 9. The insulating washer 8 has, for example, the same outer and inner diameter dimensions as the metal washer 6.

[0023] Collar 11 is made of a high-strength material, such as steel. Collar 11 has an inner bore 11c through which bolt 5, covered by insulating sleeve 7, passes. Collar 11 has a small-diameter portion 11a with a fixed outer diameter, and a large-diameter flange portion 11b at one axial end of small-diameter portion 11a that protrudes radially outward from small-diameter portion 11a. Flange portion 11b is formed to have an outer diameter that is the same as or larger than those of insulating washer 8 and metal washer 6.

[0024] The small diameter portion 11a of the collar 11 is inserted into a counterbore 12 provided in a through hole 41b on the inside (opposite the tool mounting surface 2a) of the base end wall 41, and the tip of the small diameter portion 11a is brought into close contact with the counterbore surface 12a. An insulating washer 8 and a metal washer 6 are stacked in this order in the thickness direction on the end face of the collar 11 on the flange 11b side.

[0025] The insulating cover 10 is preferably elastically deformable and is made of, for example, sponge. The insulating cover 10 has an annular flat portion 10a disposed inside the base end wall 41, and a cylindrical tubular portion 10b extending perpendicularly from the flat portion 10a at the center of the flat portion 10a and fitted into the hollow hole 41a. A hollow hole 10c, through which the filament A passes, is formed in the axial direction of the tubular portion 10b.

[0026] Preferably, the tubular portion 10b closes the tubular gap between the inner peripheral surface of the hollow hole 41a and the outer peripheral surface of the filament A. For example, the tubular portion 10b has an inner diameter smaller than the outer diameter of the filament A and an outer diameter larger than the inner diameter of the hollow hole 41a, and is elastically contractible in the radial direction. In this case, the outer peripheral surface of the tubular portion 10b comes into contact with the inner peripheral surface of the hollow hole 41a, and the inner peripheral surface of the tubular portion 10b comes into contact with the outer peripheral surface of the filament A, thereby closing the gap.

[0027] In addition, the insulating cover 10 has a plurality of through holes 13 that are arranged at positions corresponding to the through holes 41b of the bracket body 4 when the tubular portion 10b is fitted into the hollow hole 41a from the inside of the bracket body 4. Each through hole 13 of the insulating cover 10 is configured in a two-stage structure (stepped shape) having a small diameter hole portion 13a into which the small diameter portion 11a of the collar 11 is inserted and a large diameter hole portion 13b into which the flange portion 11b of the collar 11 is fitted.

[0028] The large diameter hole portion 13b of the through hole 13 has an inner diameter dimension that is slightly smaller than the outer diameter dimensions of the flange portion 11b of the collar 11, the insulating washer 8, and the metal washer 6 that fit thereto. The axial length dimension of the small diameter hole portion 13a of the insulating cover 10 is set to be slightly larger than the length dimension of the small diameter portion 11a of the collar 11 minus the depth dimension of the counterbore 12 of the bracket body 4. The axial length dimension of the large diameter hole portion 13b of the insulating cover 10 is set to be equal to the sum of the thickness dimension of the flange portion 11b of the collar 11, the thickness dimension of the insulating washer 8, and the thickness dimension of the metal washer 6.

[0029] The operation of the bracket 1 and robot 20 according to this embodiment configured as described above will be described below. To attach the bracket 1 according to this embodiment to the robot 20, first, the wire A is taken out of the hollow portion 2d of the arm member 2b of the robot 20 and passed through the hollow hole 9a of the insulating plate 9. Next, the wire A that has passed through the hollow hole 9a of the insulating plate 9 is passed through the hollow hole 41a provided in the base end wall 41 of the bracket main body 4 and taken out into the bracket main body 4.

[0030] The insulating cover 10 is inserted into the bracket body 4 through the window 43a in the side wall 43 of the bracket body 4, and the wire A extending into the bracket body 4 is passed through the hollow hole 10c of the inserted insulating cover 10. Then, the cylindrical portion 10b of the insulating cover 10 is fitted into the hollow hole 41a of the bracket body 4. As a result, the flat portion 10a of the insulating cover 10 is positioned to cover the inner surface of the base end wall 41 of the bracket body 4.

[0031] Furthermore, the cylindrical portion 10b of the insulating cover 10 elastically deforms in the radial direction, so that the inner peripheral surface of the cylindrical portion 10b comes into close contact with the outer peripheral surface of the filament A, and the outer peripheral surface of the cylindrical portion 10b comes into close contact with the hollow hole 41a. As a result, the gap between the filament A and the hollow hole 41a of the bracket body 4 is sealed by the insulating cover 10.

[0032] Furthermore, the collar 11, insulating washer 8, and metal washer 6 are inserted in this order into each through hole 13 of the insulating cover 10, the small diameter portion 11a of the collar 11 is inserted into the counterbore 12 provided in the through hole 41b of the bracket body 4, and the tip of the collar 11 is abutted against the counterbore surface 12a. When the tip of the small diameter portion 11a of the collar 11 abuts against the counterbore surface 12a, the length from the inner surface of the base end wall 41 of the bracket body 4 to the flange 11b of the collar 11 becomes slightly shorter than the length of the small diameter hole portion 13a of the through hole 13 of the insulating cover 10. As a result, the insulating cover 10 is sandwiched between the inner surface of the base end wall 41 of the bracket body 4 and the flange 11b of the collar 11.

[0033] Furthermore, when collar 11 is inserted into through hole 13 of insulating cover 10, the elasticity of insulating cover 10 causes the outer peripheral surface of flange 11b of collar 11 to be in close contact with the inner peripheral surface of large diameter hole portion 13b of through hole 13. Furthermore, when insulating washer 8 and metal washer 6 are fitted into through hole 13, the elasticity of insulating cover 10 causes the outer peripheral surfaces of insulating washer 8 and metal washer 6 to be in close contact with the inner peripheral surface of large diameter hole portion 13b of through hole 13.

[0034] In this state, the insulating plate 9 is placed on the tool mounting surface 2a of the arm member 2b in a position where the hollow hole 9a faces the opening of the hollow portion 2d and the through hole 9b faces the screw hole 2c. Then, the bolt 5 fitted into the inner hole of the insulating sleeve 7 is inserted together with the insulating sleeve 7 into the metal washer 6, the insulating washer 8, the inner hole of the collar 11 and the through hole 41b, and fastened into the screw hole 2c provided in the tool mounting surface 2a.

[0035] As a result, the axial force of the bolt 5 is transmitted to the base end wall 41 of the bracket body 4 via the metal washer 6, the insulating washer 8 and the collar 11, and the base end wall 41 of the bracket body 4 is fixed to the tool mounting surface 2a of the arm member 2b with the insulating plate 9 sandwiched between them. An insulating plate 9 is sandwiched between the tool mounting surface 2a of the arm member 2b and the robot mounting surface 4a of the bracket body 4, thereby providing electrical insulation therebetween.

[0036] Furthermore, since the bolt 5 is fastened to a screw hole 2c provided in the tool mounting surface 2a of the arm member 2b, the bolt 5 and metal washer 6 are electrically connected to the arm member 2b. Furthermore, the collar 11 is brought into close contact with the counterbore surface 12a of the counterbore 12 provided in the base end wall 41 of the bracket main body 4, so is electrically connected to the bracket main body 4.

[0037] In contrast, the outer peripheral surface of bolt 5 is electrically insulated from the inner surface of the inner hole of collar 11 and the inner surface of through-hole 41b of bracket body 4 by insulating sleeve 7, and metal washer 6 is electrically insulated from collar 11 by insulating washer 8. Therefore, bolt 5 and metal washer 6 are electrically insulated from bracket body 4 and collar 11, and the bracket body 4 and robot body 2 are electrically insulated from each other.

[0038] The tool 3 is attached to the tool attachment surface 4b of the bracket body 4 fixed to the tool attachment surface 2a. If the tool 3 has a hollow structure, the umbilical member A is drawn into the inside of the bracket body 4 from the opening of the hollow portion 2d of the arm member 2b at the tip, and is connected to the tool 3 via the window 42a in the tip wall 42. If the tool 3 does not have a hollow structure, the umbilical member A is drawn from the inside of the bracket body 4 to the outside of the bracket body 4 via the window 43a in the side wall 43, and is connected to the tool 3.

[0039] If the tool 3 is for welding, for example, there is a possibility that the current output from the tool 3 will flow into the bracket body 4. According to this embodiment, the bracket body 4 and the robot body 2 are insulated from each other, so that the current can be prevented from flowing from the bracket body 4 into the robot body 2.

[0040] 4 and 5, when the bracket body 4 is fixed to the tool mounting surface 2a, the inner surface of the base end wall 41 of the hollow bracket body 4, including the gap between the wire A and the hollow hole 41a, is almost entirely covered by the insulating cover 10. Only the heads 5a of the multiple bolts 5 and the metal washers 6 are exposed and not covered by the insulating cover 10. If the tool 3 is for welding, there is a possibility that foreign matter such as spatter produced during welding will also adhere to the inside of the bracket body 4.

[0041] In this case, the surface of collar 11 that is electrically connected to bracket body 4 is tightly covered by large-diameter hole portion 13b of through hole 13 in insulating cover 10 and insulating washer 8, and is not exposed. Furthermore, with bracket 1 and robot 20 according to this embodiment, the outer peripheral surfaces of flange portion 11b of collar 11 and insulating washer 8 are tightly fitted into large-diameter hole portion 13b of through hole 13 in insulating cover 10. Therefore, even if foreign matter such as spatter adheres to head 5a of bolt 5 and metal washer 6 that are exposed from insulating cover 10, the electrical insulation of region B between collar 11 and bolt 5 or metal washer 6 is not reduced.

[0042] Furthermore, the cylindrical portion 10b of the insulating cover 10 covering the hollow hole 41a prevents foreign matter from adhering to the inner peripheral surface of the hollow hole 41a and the inner peripheral surface of the hollow portion 2d, thereby preventing electrical conduction between the inner peripheral surface of the hollow hole 41a and the inner peripheral surface of the hollow portion 2d in the region C.

[0043] Furthermore, if the insulating cover 10 is elastically deformable, the insulating cover 10 adheres to the outer peripheral surface of the wire A and the inner peripheral surface of the hollow hole 41a due to its elastic restoring force, thereby more reliably preventing the intrusion of foreign matter such as spatter. This more reliably prevents the electrical insulation between the bracket main body 4 and the robot main body 2 from deteriorating.

[0044] In particular, when the inner surface of bracket body 4 has irregularities, for example, when the inner surface is a cast surface, flat portion 10a deforms along the irregular shape of the inner surface of base end wall 41, thereby preventing a gap from being formed between flat portion 10a and the inner surface of base end wall 41. In this way, insulating cover 10 can reliably block areas that could serve as entry points for foreign matter to enter areas B and C.

[0045] Furthermore, according to this embodiment, since the bracket body 4 is electrically insulated from the robot body 2, there is no need for electrical insulation between the bracket body 4 and the tool 3. Therefore, the worker can attach and detach the tool 3 to and from the tool attachment surface 4b without needing to perform additional work to ensure electrical insulation between the tool 3 and the robot body 2.

[0046] The flow of current from the tool 3 to the robot body 2 can also be prevented by providing an insulating member between the bracket body 4 and the tool 3. In this case, however, when attaching or detaching the tool 3 to or from the tool mounting surface 4b, the insulating member must also be attached or detached, which increases the number of parts to be handled and the amount of work involved.

[0047] Furthermore, according to this embodiment, the bracket 1 itself is provided with an insulating structure that insulates the bracket 1 from the robot body 2, and the bracket 1 is fixed to the tool mounting surface 2a separated only by a thin insulating plate 9. This makes it possible to reduce the offset amount from the tool mounting surface 2a to the tool mounting surface 4b, the total weight of the members attached to the tool mounting surface 2a, and costs.

[0048] The bracket 1 can also be electrically insulated from the robot body 2 by placing an insulating member between the tool mounting surface 2a and the bracket 1 and fixing the bracket 1 to the insulating member instead of the tool mounting surface 2a. In this case, however, a thick insulating member is required, which increases the offset amount, total weight, and cost.

[0049] In this way, simply by fastening the bolts 5 into the threaded holes 2c in the tool mounting surface 2a, the bracket body 4 can be fixed to the tool mounting surface 2a in an electrically insulated state, and the insulating cover 10 can be attached to the bracket body 4. Therefore, the bracket 1 can be attached to the arm member 2b and the insulating cover 10 can be attached to the bracket body 4 at the same time, which has the advantage of reducing the number of members required for fixing and making the fixing process less complicated.

[0050] In this embodiment, the insulating sleeve 7 and the insulating washer 8 are provided separately, but they may also be formed integrally. Also, the insulating plate 9 may be provided as part of the robot body 2 or part of the bracket body 4. Also, the insulating plate 9 may be formed integrally with the insulating sleeve 7.

[0051] Furthermore, by placing a metal washer 6 having the same outer diameter as the insulating washer 8 on top of the insulating washer 8, the force received from the head 5a of the bolt 5 can be dispersed over the entire surface of the insulating washer 8 by the metal washer 6, thereby preventing damage to the insulating washer 8 due to stress concentration. Alternatively, if the insulating washer 8 can be made of a material with sufficient strength, the metal washer 6 may not be necessary.

[0052] In the above embodiment, the collar 11 may be fitted into the counterbore 12 of the bracket body 4, and the bracket body 4 and the arm member 2b may be positioned by a pin or the like. In this case, a gap is formed between the through hole 41b of the bracket body 4 and the inner hole 11c of the collar 11 and the outer circumferential surface of the bolt 5, so that the insulating sleeve 7 is not necessary.

[0053] Furthermore, in the above embodiment, the insulating cover 10 has a tubular portion 10b that covers the inner surface of the hollow hole 41a, but if the hollow hole 41a can be covered by only the flat portion 10a, the insulating cover 10 does not necessarily have to have the tubular portion 10b. That is, when the inner peripheral surface of the flat portion 10a contacts the outer peripheral surface of the filament A and the gap between the inner peripheral surface of the hollow hole 41a and the outer peripheral surface of the filament A is blocked by the flat portion 10a, it is possible to prevent foreign matter from entering the hollow hole 41a only by the flat portion 10a. Therefore, in such a case, the cylindrical portion 10b does not need to be provided.

[0054] In the above embodiment, the insulating cover 10 does not necessarily have to be elastically deformable. For example, the insulating cover 10 may be made of a hard material. When the insulating cover 10 is an elastically deformable material such as a sponge, even if the length of the small diameter hole portion 13a of the through hole 13 is not strictly specified, the elastic deformation of the insulating cover 10 can achieve both fixing of the insulating cover 10 and fixing of the bracket 1 to the arm member 2b.

[0055] Furthermore, if the insulating cover 10 is an elastically deformable material such as a sponge, the insulating cover 10 can be easily inserted into the bracket body 4 through the window 43a. On the other hand, if the insulating cover 10 is not elastically deformable, it may be difficult to pass the insulating cover 10 through the window 43a. In this case, the insulating cover 10 may be divided into multiple members each having a size that allows them to pass through the window 43a.

[0056] In this embodiment, the one-piece insulating cover 10 has a two-tiered through hole 13 including a small-diameter hole portion 13a and a large-diameter hole portion 13b. Alternatively, as shown in Fig. 6, the insulating cover 10 may be divided into two in the thickness direction, with one insulating cover (second cover) 10A having a large-diameter hole portion (second through hole) 13b and the other insulating cover (first cover) 10B having a small-diameter hole portion (first through hole) 13a. The two insulating covers 10A and 10B are then combined in a stacked state to form a two-tiered through hole 13 similar to that shown in Fig. 5.

[0057] In this case, the two insulating covers 10A, 10B may be fixed to each other in a stacked state by adhesive, etc. This simplifies processing because each insulating cover 10A, 10B only needs to have through holes of different sizes but uniform diameters.

[0058] In this embodiment, the flange portion 11b of the collar 11, the insulating washer 8, and the metal washer 6 are fitted in a stacked state into the large-diameter hole portion 13b of the through-hole 13 provided in the insulating cover 10. Alternatively, as shown in Fig. 7, the metal washer 6 may be exposed to the outside of the large-diameter hole portion 13b. This also allows the insulating washer 8 to prevent a decrease in electrical insulation between the metal washer 6 and the collar 11 due to the adhesion of spatters and the like.

[0059] 8, the outer diameter of metal washer 6 may be set sufficiently larger than the inner diameter of through hole 13, so that metal washer 6 holds insulating cover 10 from the surface. This eliminates the need to hold insulating cover 10 with flange 11b of collar 11, so collar 11 can be configured as a simple cylinder and through hole 13 as a simple hole with a circular cross section and a single inner diameter, making it easier to manufacture insulating cover 10 and collar 11.

[0060] 9, instead of using the metal washer 6 to hold the insulating cover 10, an insulating washer 8 may be used that has an outer diameter that is larger than the inner diameter of the through hole 13 and is equivalent to that of the metal washer 6. This allows the insulating cover 10 to be held down by the insulating washer 8, which also simplifies the shapes of the insulating cover 10 and the collar 11.

[0061] 10, instead of using the bolt 5 and metal washer 6, a flanged bolt 14 in which the bolt head 14a and flange 14b are integrally formed may be used as the bracket fixing device. The flange 14b of the flanged bolt 14 can press down on the insulating cover 10 while closing the through hole 13.

[0062] In addition, in this embodiment, a collar 11 made of a high-strength material, such as steel, is used, but a collar 15 made of an electrically insulating material may be used as long as the strength is ensured. For example, as shown in Fig. 11, if a collar 15 with a flange 15a is used, the insulating washer 8, insulating sleeve 7, and metal washer 6 are not required, and the shape of the through hole 13 in the insulating cover 10 can be simplified, improving ease of manufacture.

[0063] Furthermore, as shown in FIG. 12, by combining with a metal washer 6, a collar 15 made of an electrically insulating material can also be configured in a simple cylindrical shape. Furthermore, although the counterbore 12 for inserting the collars 11 and 15 is provided on the inner surface of the bracket body 4, if the inner surface of the bracket body 4 can instead be made into a machined seat surface, the counterbore 12 for abutting the tips of the collars 11 and 15 can be omitted.

[0064] In the above embodiment, as shown in FIG. 13, the bracket 1 may further include an annular clamp 16 that is disposed in the hollow hole 41a and fixes the filament A to the tool attachment surface 2a.

[0065] 14, the clamp 16 has two semicircular arc-shaped parts 16a and 16b that sandwich the filament A in the radial direction. An elastic body 17 is wound around the outer circumferential surface of the filament A, and the elastic body 17 is disposed between the filament A and the clamp 16.

[0066] The two parts 16a and 16b are fixed in close contact with the outer circumferential surface of the filament A, separated by an elastic body 17. The parts 16a and 16b are fixed by, for example, screwing a bolt 16c into a bolt hole 16d in the parts 16a and 16b. The clamp 16 is fixed to the tool mounting surface 2a by a bolt (not shown).

[0067] 13, the gap between the inner peripheral surface of hollow hole 41a and the outer peripheral surface of wire body A is blocked by clamp 16 and elastic body 17, so there may be a gap between hollow hole 10c of insulating cover 10 and the outer peripheral surface of wire body A, and insulating cover 10 does not need to have cylindrical portion 10b. Flat portion 10a extends radially inward beyond the outer peripheral surface of clamp 16 and covers the entire inside of clamp 16. According to this configuration, by fixing the filament A in the hollow hole 41a of the base end wall 41, movement of the filament A within the bracket main body 4 can be suppressed.

[0068] Furthermore, in the above embodiment, the bracket 1 is used to attach a hollow or solid tool 3 to the hollow arm member 2b, but instead, it may be used to attach a hollow tool 3 to a solid arm member 2b. In this case, the bracket 1 may be provided as a part of the welding device. That is, the welding device according to this embodiment includes the bracket 1 and the hollow welding tool 3.

[0069] The hollow welding tool 3 is attached to the robot mounting surface 4a, into which the hollow hole 41a opens, using a bolt 5 and a metal washer 6, and the tool 3 and the bracket main body 4 are electrically insulated by an insulating sleeve 7, an insulating washer 8, and an insulating plate 9. At least one wire A is wired between the hollow portion of the tool 3 and the inside of the bracket main body 4 through the hollow hole 41a. The bracket main body 4 is attached to the tool mounting surface 2a of the solid arm member 2b at the tool mounting surface 4b. In this case, the tip wall 42 does not need to have a window 42a, and may have a through-hole (not shown) instead of the screw hole 42b.

[0070] In the above embodiment, the bracket 1 may be provided as part of a welding robot system. That is, the robot system according to this embodiment includes a robot 20 having the bracket 1 and a robot body 2, and a welding device having a tool 3 such as a welding gun. The welding device is fixed to the tip of the robot body 2 across the bracket 1. [Explanation of symbols]

[0071] 1 bracket 2 Robot body 2a Tool mounting surface 2b Arm member at the tip 2c screw hole 2d hollow part 3 Tools, welding tools 4 Bracket body 5 bolts (bracket fixing) 5a,14a Head 6 Metal washers (bracket fixing devices) 8 Insulating washer (insulating material) 10, 10A, 10B Insulation cover (1st cover, 2nd cover) 11,15 Color 11a Small diameter section 11b Tsubabe 13a Small diameter hole (first through hole) 13b Large diameter hole (second through hole) 14 Flanged bolt (bracket fixing device) 16 Clamp 20. Robot 41a Hollow hole 41b Through hole A. Striatum

Claims

1. a hollow bracket body that is attached to a tool attachment surface of a hollow arm member with an electrically insulating plate interposed therebetween; an insulating member that electrically insulates the bracket body from a bracket fixing tool that fixes the bracket body to the tool mounting surface from the inside of the bracket body; an electrically insulating cover disposed inside the bracket body, the bracket body, the insulating plate, and the insulating cover have hollow holes through which a wire can be passed from the arm member to the inside of the bracket body via an opening in the tool mounting surface, the bracket fixing device includes one or more bolts that pass through through holes provided in the bracket body, the insulating plate, and the insulating cover and are fastened to screw holes provided in the tool mounting surface, The insulating cover covers the gap between the hollow hole of the bracket body and the wire body, and is fixed to the bracket body by fastening the bolt.

2. a cylindrical collar disposed in the through hole of the insulating cover, through which each of the bolts passes, and axially sandwiched between a head of each of the bolts and the bracket body; 2. The bracket according to claim 1, wherein the insulating member comprises an insulating washer sandwiched between one axial end of the collar and the head of the bolt and tightly fitted over the entire inner circumferential surface of the through hole of the insulating cover.

3. 2. The bracket according to claim 1, wherein the insulating member comprises an electrically insulating cylindrical collar disposed within the through hole of the insulating cover, through which each of the bolts passes, and axially sandwiched between the head of each of the bolts and the bracket body.

4. 4. The bracket according to claim 1, wherein the insulating cover is elastically deformable.

5. 5. The bracket according to claim 1, further comprising an annular clamp disposed in the hollow hole and configured to fix the wire member to the tool mounting surface.

6. the collar includes a small diameter portion and a flange portion that protrudes radially outward from one end of the small diameter portion, 3. The bracket according to claim 2, wherein the through hole of the insulating cover has a stepped shape into which the outer circumferential surface of the small diameter portion of the collar and the outer circumferential surface of the flange portion of the collar are fitted.

7. 7. The bracket according to claim 6, wherein the insulating cover is constructed by stacking a first cover having a first through hole into which the outer peripheral surface of the small diameter portion of the collar is fitted, and a second cover having a second through hole into which the outer peripheral surface of the flange portion of the collar is fitted.

8. a robot body having at least one arm member, the arm member at the tip of which is hollow; A robot comprising the bracket according to any one of claims 1 to 7.

9. The bracket according to any one of claims 1 to 7; a hollow welding tool; The welding tool is attached to the outer surface of the bracket body where the hollow hole opens, and at least one wire is wired between the hollow portion of the welding tool and the interior of the bracket through the hollow hole.

10. The robot according to claim 8; a tool fixed to the tip of the robot body across the bracket.

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