JP2013094860A - Wrist structure of industrial robot and assembling method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wrist structure of an industrial robot in which foreign objects accumulated in a hole formed in the outer peripheral part of a second connection member can be reduced and the outer peripheral part of the second connection member can be easily cleaned.SOLUTION: The wrist structure 1 includes a first cylindrical connection member 11 and a second cylindrical connection member 12, and an articulated body 15. The articulated body 15 includes an outer annular member 21 fixed to one opening end 11e of the first connection member 11, and an inner tubular member 22 turnably disposed in the outer annular member 21. In the inner annular member 22 and the second connection member 12, a first bottomed through-hole 28 is formed from the inner annular member 22 to the second connection member 12. A bolt 29 is inserted into the first through-hole 28 from the inner annular member 22 side. The inner annular member 22 of the articulated body 15 is fastened to the inner annular member 12 by using the bolt 29.

Description

  The present invention relates to a wrist structure for an industrial robot, which is attached to a distal end portion of an arm and has a continuous passage from the arm to the distal end portion thereof, and an assembling method thereof.

  In an industrial robot, an end effector such as a coating nozzle or a tool is provided at the tip of an arm via a wrist structure in order to improve the degree of freedom. For example, the wrist structure disclosed in Patent Document 1 includes a plurality of cylindrical joint portions, and has a passage for passing a linear body such as a hose or cables from the arm to the end effector. The first joint has one open end fixed to the tip of the arm. A bevel gear is rotatably provided inside the other opening end portion of the first joint portion, and one opening end portion of the second joint portion is fastened to the bevel gear by a bolt. Yes. The second joint portion rotates relative to the first joint portion by rotating the bevel gear.

JP 2008-73775 A

  In the wrist structure described in Patent Document 1, a through-hole for passing a bolt for fixing the bevel gear and the second joint portion is formed in the second joint portion. The through hole is open to the outside of the second joint portion, and a bolt is inserted from the outside. Therefore, the opening of the through hole is exposed to the outside, and foreign matter may enter through this opening and accumulate in the through hole. In particular, when the wrist structure is used by a painting robot or the like, the rebound paint may enter from the opening that appears on the outside. The entered paint accumulates in the through-holes, but the accumulated paint may scatter during the operation, and the scatter and adhere to the product leads to a reduction in product quality. Cleaning the outer periphery of the wrist structure to remove the paint adhering to the wrist structure to prevent such quality deterioration, but it is difficult to clean if a plurality of openings are formed in the outer periphery of the second joint part, Long cleaning time.

  Accordingly, the present invention provides a wrist structure for an industrial robot capable of reducing foreign matter accumulated in a hole formed in the outer peripheral portion of the second connecting member and facilitating cleaning of the outer peripheral portion of the second connecting member. The purpose is to provide.

  The wrist structure of the industrial robot of the present invention is attached to the tip of an arm and has a continuous passage from the arm to the tip of the arm. The first connecting member formed in a cylindrical shape, An annular fixing member fixed to one opening end of one connecting member, and a joint body having an annular first rotating member rotatably provided inside the fixing member, and formed in a cylindrical shape. The second connecting member fastened to the first rotating member of the joint body so that the inner space is connected to the inner space of the first connecting member, and the first rotating member and the second connecting member. A first fastening member to be fastened, and the first rotating member and the second connecting member are formed with a bottomed first through hole reaching the second connecting member from the first rotating member, The first fastening member passes through the first through hole from the first rotating member side. It is what is.

  According to the present invention, the first through hole is bottomed, and the first fastening member is passed from the first rotating member side, so that the opening of the first through hole is the first connecting member. Does not appear outside. Therefore, it is not necessary to form a hole for passing the first fastening member in the outer peripheral portion of the second connecting member, and the number of holes formed in the outer peripheral portion of the second connecting member can be reduced. Thereby, it can suppress that a foreign material accumulates in a hole like a prior art, and can make it easy to clean the outer peripheral part of a 2nd connection member.

  In the above invention, the first connecting member is formed such that an angle formed by the opening direction of the one opening and the other opening different from the one opening is an obtuse angle, and the first rotating member and the second connecting member The plurality of first through holes are formed, the plurality of first through holes extend from the second connecting member in a predetermined direction, and the first connecting member includes the plurality of first through holes. Only a part of the first through hole is formed so as to be exposed in the predetermined direction from the other opening, and the second connecting member is rotated relative to the first connecting member. It is preferable that the plurality of first through holes are configured to be exposed in order.

  If the said structure is followed, since the angle which the opening direction of one opening part and the other opening part makes becomes an obtuse angle, by rotating a 2nd connection member relatively with respect to a 1st connection member, it is 1st. 2. The direction of the connecting member can be changed in various directions. In addition, despite the fact that the angle formed by the opening direction of one opening and the other opening is an obtuse angle, some of the plurality of first through holes are exposed in a predetermined direction from the other opening. Therefore, the tool for fastening the first fastening member can be put straight from the other opening. Therefore, tools are easy to put in and work. Furthermore, since the hidden first through hole can be exposed by turning the second connecting member relative to the first connecting member, only a part of the first through holes can be exposed from the other opening. It is easy to pass the first fastening member through all the first through holes, and the wrist structure can be easily assembled.

  In the above invention, the second rotating member rotatably provided inside the first rotating member and the first rotating member are formed in a cylindrical shape, and the first space is connected to the inner space of the second connecting member. A third connecting member rotatably provided on the two connecting members and rotating in conjunction with the second rotating member; and a rotation for rotating the first rotating member and the second rotating member. The first rotation member has a first gear portion to which power from the rotation drive unit is transmitted, and the second rotation member is connected to the rotation drive unit. It is preferable that a second gear portion to which power is transmitted is provided, and the first fastening member is disposed between the first gear portion and the second gear portion.

  If the said structure is followed, the external dimension of a 1st gear part can be enlarged compared with the case where a 1st fastening member is arrange | positioned on the outer side of a 1st gear part. Thereby, durability of a 1st gear part can be improved, without enlarging a 1st connection member.

  In the above invention, a second fastening member that fastens and fixes the fixing member to the first connecting member is provided, and the fixing member and the first connecting member have one opening of the first connecting member from the fixing member. It is preferable that a bottomed second through hole reaching the portion is formed, and the second connecting member has a covering portion that covers the second through hole.

  If the said structure is followed, since the 2nd through-hole for fastening with the said fixing member and a 1st connection member is covered, the number of the holes opened to the outward of a wrist structure can be reduced. Thereby, it can suppress that a foreign material accumulates in a hole, and it becomes easy to clean the outer peripheral part of a wrist structure.

  The present invention is a wrist structure for an industrial robot that is attached to the tip of an arm and has a continuous passage from the arm to the tip of the arm. The first connection member formed in a cylindrical shape, and the first connection An annular fixing member fixed to one opening end of the member, and an articulation body having an annular first rotating member rotatably provided inside the fixing member; The second connecting member fastened to the first rotating member of the joint body and the first rotating member and the second connecting member are fastened so that the internal space is connected to the internal space of the first connecting member. A first fastening member, and the first rotating member and the second connecting member are provided with a bottomed first through hole reaching the second connecting member from the first rotating member, The one fastening member is passed through the first through hole from the first rotating member side. In the method of assembling the wrist structure of the industrial robot, the first rotating member is inserted into the first through hole of the first rotating member of the joint body fixed to the first connecting member. It is a method which has the fastening process which fastens the 2nd connecting member, and the connecting process which connects the 1st connecting member to the tip of the arm after the fastening process.

  If the said structure is followed, since the hole for fastening with the said fixing member and the 1st connection member is not exposed outside, the wrist structure which can reduce the number of the holes opened outside is assembled easily. Can do. Further, since the wrist structure can be assembled from the tip end side, the wrist structure can be assembled first separately from the robot, so that the time required for attachment to the robot can be shortened.

  In the above invention, in the above-described method for assembling the wrist structure for an industrial robot, the first connecting member has an obtuse angle formed by the opening direction of the one opening and the other opening. A plurality of first through holes are formed in the first rotating member and the second connecting member, and the plurality of first through holes extend from the second connecting member in a predetermined direction. The first connecting member is formed such that only a part of the first through-holes of the plurality of first through-holes is exposed from the other opening toward the predetermined direction. The second connecting member is rotated relative to the first connecting member to sequentially expose the plurality of first through holes, and the first fastening members are sequentially inserted into the first through holes to be exposed. The first rotating member and the second connecting member are fastened through It is preferable that is a cormorant.

  If the said structure is followed, since the 1st through-hole which is hidden can be exposed by turning the 2nd connection member with respect to a 1st connection member, a some 1st through-hole is exposed sequentially and there. By passing the first fastening member through the first fastening member, it is possible to pass the first fastening member through all the first through holes. Therefore, even if the wrist structure has only a part of the first through-holes exposed from the other opening, it is easy to pass the first fastening member through all the first through-holes, and the wrist structure can be easily assembled. be able to.

  According to the present invention, it is possible to reduce foreign substances accumulated in the hole formed in the outer peripheral portion of the second connecting member, and it is possible to facilitate cleaning of the outer peripheral portion of the second connecting member.

It is a side view which shows the wrist structure which concerns on embodiment of this invention. It is sectional drawing which shows the state which attached the wrist structure of FIG. 1 to the arm of the industrial robot. FIG. 3 is an exploded view showing the wrist structure shown in FIG. 2 in an exploded manner. It is a flowchart which shows the assembly | attachment method of the wrist structure of FIG. FIG. 4 is an exploded view showing a state in which the joint body is attached to the first connecting member in the wrist structure shown in FIG. 3. In the wrist structure shown in FIG. 5, it is an exploded view which shows the state which attached the 2nd connection member to the joint body. It is the perspective view which looked at the wrist structure of FIG. 1 from the other opening part side of the 1st connection member. In the wrist structure shown in FIG. 6, it is an exploded view which shows the state which attached the bearing holding member to the 2nd connection member. It is the perspective view which looked at the wrist structure of FIG. 1 from the bottom.

  Below, the wrist structure 1 of embodiment of this invention is demonstrated, referring drawings mentioned above. In addition, the same reference number is attached | subjected to the element which is the same or it corresponds through all the figures, and the overlapping description is abbreviate | omitted. Moreover, the concept of the direction used in the following description is used for convenience of description, and is not necessarily limited to that direction. Moreover, the wrist structure 1 described below is only one embodiment of the present invention. Therefore, the present invention is not limited to the embodiments, and can be added, deleted, or changed without departing from the spirit of the invention.

[Configuration of wrist structure]
The wrist structure 1 is provided in an industrial robot 2 (see FIG. 2) that is configured such that an attachment such as a painting gun, a welding gun, or a tool can be attached to the tip of the wrist structure 1. The industrial robot 2 is an articulated robot, for example, and works by moving the attachment to an arbitrary position. The industrial robot 2 has an arm 2a (see FIG. 2) on the tip side, and a wrist structure 1 as shown in FIG. 1 is provided at the tip of the arm 2a.
As shown in FIGS. 1-3, the wrist structure 1 has the three cylindrical connection members 11-13.

<First connecting member>
The first connecting member 11 has a substantially triangular shape in a side view, and the opening direction of one opening 11a (that is, the normal direction of the opening, see FIG. 3) A1 and the opening direction of the other opening 11b. The angle α formed with A2 (see FIG. 3) is an obtuse angle, which is about 120 degrees in this embodiment. Further, an arcuate tubular portion 14 is formed in the first connecting member 11 in a side view. The tubular portion 14 has a first communication passage 14a therein, and the two opening portions 11a and 11b are connected by the first communication passage 14a. In addition, the second connecting member 12 is rotatably provided at one opening end portion 11e defining the one opening portion 11a via the joint body 15, and the other opening portion 11b is described later. As described above, the tip of the arm 2a of the industrial robot 2 is inserted.

<Joint body>
The joint body 15 is a substantially annular member, and is provided at one opening end portion 11e so as to be partially inserted into the one opening portion 11a. The joint body 15 includes an outer annular member 21, a central annular member 22, and an inner annular member 23. The outer annular member 21 as a fixing member is an annular member for holding the outer bearing member 25 on the inner peripheral portion thereof. The outer peripheral surface of the outer annular member 21 is substantially flush with the outer peripheral surface of the first connecting member 11, and an annular outer bearing member 25 is fitted inside the inner peripheral portion thereof. More specifically, the outer annular member 21 has two annular holding portions 21a and 21b, and one opening end portion so that the two holding portions 21a and 21b substantially coincide with each other. 11e is provided so as to overlap. The two holding portions 21a and 21b are fastened to one opening end portion 11e by a plurality of bolts 24 penetrating them. Moreover, the protrusion part which protrudes in a radial direction is formed in the inner peripheral part of each holding | maintenance part 21a, 21b. The outer bearing member 25 is interposed between the projecting portions, and the outer edge portion of the outer bearing member 25 is sandwiched by the projecting portions by fastening the holding portions 21a and 21b to the one open end portion 11e. . A central annular member 22 is fitted into the outer bearing member 25, and the central annular member 22 is provided on the outer annular member 21 via the outer bearing member 25.

  The central annular member 22 that is the first rotating member is a substantially annular member, and the second connecting member 12 is fastened to the opening end on the tip side. More specifically, the central annular member 22 has two first bevel gears 26 and a spacer portion 27 that are formed in an annular shape, and the first bevel gear 26 and the spacer portion 27 have axes thereof. It is piled up so that it may be in agreement. The first bevel gear 26 is inserted into one opening 11a. An umbrella-shaped tooth portion 26a is formed on the outer edge portion of the first bevel gear 26 over the entire circumference in the circumferential direction, and a plurality of fastening holes 18 and a plurality of first through holes are formed on the inner side of the outer edge portion. 28 is formed.

  The fastening holes 18 are arranged at regular intervals, for example, at regular intervals, and extend in the axial direction of the joint body 15, that is, in the opening direction B1. The fastening hole 18 is a bottomed hole having an opening in the first connecting member 11, and reaches the spacer portion 27. That is, the bottom of the fastening hole 18 is formed in the spacer portion 27. A bolt 19 is passed through the fastening hole 18 from the side of the first bevel gear 26 having an opening. The bolt 19 is screwed into the spacer portion 27 and fastens the first bevel gear 26 to the spacer portion 27. A first through hole 28 is located between the adjacent fastening holes 18.

  The first through holes 28 are formed at regular intervals, for example, at regular intervals, and extend in the axial direction of the joint body 15, that is, in the opening direction B1. The first through hole 28 is a bottomed hole having an opening in the first connecting member 11 and penetrates the spacer portion 27. The spacer portion 27 is in contact with one open end 12c of the second connecting member 12, which will be described in detail later. The first through hole 28 reaches the second connecting member 12, and the second connecting member 12 is in contact with the second connecting member 12. The bottom of the member 12 is formed. A bolt 29 (first fastening member) is passed through the first through hole 28 from the side of the first bevel gear 26 having an opening, and the passed bolt 29 is further screwed into the second connecting member 12. The first bevel gear 26 and the spacer portion 27 are fastened to the second connecting member 12. In addition, protrusion portions are formed on the outer peripheral portions of the first bevel gear 26 and the spacer portion 27, respectively, and these protrusion portions fasten the first bevel gear 26 and the spacer portion 27 to the second connecting member 12. Thus, the outer bearing member 25 is sandwiched.

  Note that the positions of the fastening hole 18 and the first through hole 28 in the first bevel gear 26 are not necessarily limited to the positions described above. Further, the fastening hole 18 may be replaced with the first through hole 28. For example, the fastening hole 18 may be eliminated and all the holes may be used as the first through hole first through hole 28.

  In this way, the bolt 29 is passed from the first connecting member 11 side, that is, from the central annular member 22 located in the first connecting member 11 to the first through hole 28, and the bottom of the bolt 29 is passed to the second connecting member 12. Since it is formed, the opening of the first through hole 28 does not appear outside. Therefore, there is no need to form a through hole for passing the bolt 29 in the outer peripheral portion of the second connecting member 12. Thereby, the number of holes formed in the outer peripheral portion of the second connecting member 12 can be reduced, foreign matter can be prevented from accumulating in the holes, and the outer peripheral portion of the second connecting member 12 can be suppressed. Easy to clean.

<Second connecting member>
The second connecting member 12 is formed in a substantially triangular shape in a side view like the first connecting member 11, and the opening direction of one opening 12a (that is, the normal direction of the opening surface) B1 and the other opening. The angle β formed by the opening direction B2 of the portion 12b (the lower opening in FIG. 1) is an obtuse angle, which is about 120 degrees in this embodiment. In addition, an arcuate tubular portion 16 is formed in the second connecting member 12 in a side view, and the tubular portion 16 has a second communication passage 16a that connects the two openings 12a and 12b therein. doing.

  In the second connecting member 12 having such a shape, a part of the first through hole 28 is formed at one opening end 12c that defines one opening 12a. A spacer portion 27 is disposed at one opening end portion 12 c so that the axes thereof coincide with each other, and the first bevel gear 26 and the spacer portion 27 are fastened thereto by bolts 29. In addition, a flange portion 12d is formed on the outer peripheral portion of the second connecting member 12 so as to extend over the entire circumference in the circumferential direction on the one opening 12a side. The flange portion 12 d that is the covering portion protrudes outward in the radial direction and faces the outer annular member 21. A plurality of second through holes 30 for passing the bolts 24 (second fastening members) are formed in the outer peripheral edge portion of the outer annular member 21, and the second through holes 30 are equally spaced in the circumferential direction. Open each one. The second through hole 30 is a low and low hole that penetrates the outer annular member 21 to reach the first connecting member 11 and has a bottom in the first connecting member 11, and the opening thereof is covered by the flange portion 12d. . By covering the opening of the second through hole 30 in this way, it is possible to prevent foreign matters such as paint from collecting in the second through hole 30, and it is possible to prevent the accumulated foreign matter from scattering. On the other hand, a bearing holding member 31 is provided at the other open end 12 e of the second connecting member 12.

  The bearing holding member 31 is a substantially annular member, and a generally annular front end side bearing member 32 is fitted inside the bearing holding member 31. More specifically, the bearing holding member 31 has two annular holding portions 31a and 31b, and the other opening end portion so that the two holding portions 31a and 31b substantially coincide with each other. 12e is arranged so as to overlap. The two holding portions 31a and 31b are fastened to the other opening end portion 12e by a plurality of bolts 33 penetrating them. Projection portions projecting in the radial direction are formed on the inner peripheral portions of the holding portions 31a and 31b, and the tip-end side bearing member 32 is interposed between these projection portions. And the outer edge part of the front end side bearing member 32 is clamped by the projection part by fastening holding | maintenance part 31a, 31b to the other opening edge part 12e. A rotating member 34 is fitted in the front end side bearing member 32 thus sandwiched.

  The rotating member 34 is a cylindrical member, and is inserted into the second connecting member 12 from the other opening 12b. The outer peripheral portion on the front end side of the rotating member 34 has a smaller diameter than the remaining portion, and the front end side bearing member 32 is fitted on the outer peripheral portion on the front end side. A cylindrical third connecting member 13 is disposed at the tip of the rotating member 34.

<Third connecting member>
The proximal end portion of the third connecting member 13 is inserted into the bearing holding member 31 and sandwiches the inner edge portion of the distal end side bearing member 32 together with the outer peripheral portion of the rotating member 34. The third connecting member 13 is arranged so that the axes of the third connecting passages 13a are substantially aligned with each other so that the third communicating passage 13a is connected to the internal space of the rotating member 34, and the third connecting member 13 is rotated by a plurality of bolts 35. It is fastened to the tip of the moving member 34 (see also FIG. 9). The bolt 35 is provided on the inner side of the third connecting member 13, and the hole through which the bolt 35 passes is not exposed to the outside. On the other hand, the attachment etc. which are not shown in figure are attached to the front-end | tip part of the 3rd connection member 13 so that attachment or detachment is possible.

  A flange portion 13 b is formed on the outer peripheral portion of the third connecting member 13 over the entire circumference in the circumferential direction. The flange portion 13 b extends outward in the radial direction and faces the bearing holding member 31. A plurality of third through holes 36 through which the bolts 33 are passed are formed in the outer edge portion of the bearing holding member 31, and the third through holes 36 are positioned at equal intervals in the circumferential direction. . The third through hole 36 passes through the bearing holding member 31 and reaches the second connecting member 12, and the bottom thereof is a bottomed hole formed in the second connecting member 12, and the opening thereof is formed by the flange portion 13 b. Covered. By covering the opening of the third through hole 36 in this way, it is possible to prevent foreign matters such as paint from collecting in the hole and scattering of the foreign matter. Further, the outer peripheral surface of the flange portion 13 b is substantially flush with the outer peripheral surface of the bearing holding member 31.

<Gear meshing structure>
Further, the base end side (that is, the arm 2a side) portion of the inner peripheral portion of the rotating member 34 has a larger diameter than the remaining portion, and there is a tubular portion 16 of the second connecting member 12 there. One open end 16b is inserted. The rotating member 34 has a second bevel gear 37 at a base end portion thereof (that is, an end portion on the arm 2a side), and the outer peripheral edge of the second bevel gear 37 has an umbrella shape over the entire circumference in the circumferential direction. The tooth part 37a is formed. The second bevel gear 37 is positioned so as to surround one open end 16b. A first communication space 38 having a C-shaped cross section that connects the other opening 12 b and the one opening 12 a is formed around the tubular portion 16, and a second umbrella located in the first communication space 38. A part of the gear 37 is located in the one opening 12 a of the second connecting member 12. An inner annular member 23 that constitutes the joint body 15 is located in the one opening 12a.

  The inner annular member 23 which is the second rotating member is a substantially annular member, and is provided rotatably on the central annular member 22 via an inner bearing member 39 fitted in the central annular member 22. Yes. More specifically, the inner peripheral portions of the first bevel gear 26 and the spacer portion 27 are each formed with a protruding portion like the outer peripheral portion, and the inner bearing member 39 is interposed between the protruding portions. The inner bearing member 39 is sandwiched between the protruding portions by fastening the first bevel gear 26 and the spacer portion 27 to the second connecting member 12. The inner annular member 23 is fitted into the inner bearing member 39.

  The inner annular member 23 has two bevel gears 40, 41, and the two bevel gears 40, 41 are overlapped and fastened by a plurality of bolts 42 so that their axis lines substantially coincide. The two bevel gears 40, 41 respectively have umbrella-shaped tooth portions 40 a, 41 a that extend over the entire circumferential direction at positions corresponding to the outer edge portions at both end portions of the inner annular member 23. The tooth portion 40a of the third bevel gear 40 is inserted into one opening portion 12a of the second connecting member 12, and meshes with the tooth portion 37a of the second bevel gear 37 located there. On the other hand, the fourth bevel gear 41 is positioned so as to surround one opening 14 b of the tubular portion 14. A second communication space 43 that connects one opening 11 a and the other opening 11 b is formed around the tubular portion 14, and the tooth portion 41 a of the fourth bevel gear 41 that is located in the second communication space 43. Is located in the other opening 11b. The tooth portion 41a (fourth gear portion) is located at a distance from the tooth portion 26a (first gear portion) of the first bevel gear 26 on the outer side in the radial direction, and has a plurality of first through holes 28. Is formed between them.

  As described above, the first through hole 28 is formed between the tooth portion 41a of the fourth bevel gear 41 and the tooth portion 26a of the first bevel gear 26, and the bolt 29 is disposed therebetween, whereby the bolt 29 is The outer dimensions of the first bevel gear 26 can be increased without changing the outer diameter of the wrist structure 1 as compared with the case where the first bevel gear 26 is disposed outside. Thereby, the durability of the first bevel gear 26 can be improved.

<Rotation drive structure>
Part of the tooth portions 26a and 41a of the first and fourth bevel gears 26 and 41 configured as described above is located in the other opening portion 11b, and the arm 2a is partially formed in the other opening portion 11b. Has been inserted.

  As shown in FIG. 2, the arm 2a is formed in a substantially cylindrical shape, and includes a casing 51 and three drive shafts 52 to 54 (rotation drive units). The casing 51 is formed in a substantially cylindrical shape, and three drive shafts 52 to 54 are accommodated therein. The first to third drive shafts 52 to 54 are formed in a substantially cylindrical shape, and the second drive shaft 53 is rotatably inserted into the first drive shaft 52. Three drive shafts 54 are rotatably inserted.

  In the present embodiment, the tip end portion of the first drive shaft 52 is fastened to the other opening end portion 11 d of the first connecting member 11, so that the first connecting member 11 rotates together with the first drive shaft 52. ing. The casing 51 has a cover portion 51a at the outer peripheral edge portion of the tip portion on the first connecting member 11 side. The cover portion 51 a has a generally annular shape and protrudes toward the first connecting member 11. The cover portion 51a prevents paint or the like scattered from the outside in the radial direction from entering the holes for inserting the bolts 51b and the pins 51c for fastening the first drive shaft 52 and the first connecting member 11. It is out.

  The second drive shaft 53 has an umbrella-shaped tooth portion 53a on the outer peripheral portion of the tip portion, and this tooth portion 53a meshes with the tooth portion 26a of the first bevel gear 26 at the other opening 11b. doing. Further, the third drive shaft 54 has a bevel tooth portion 54a on the outer peripheral portion of the tip portion, and this tooth portion 54a is connected to the tooth portion 41a of the fourth bevel gear 41 at the other opening portion 11b. Meshed.

  Each of the three drive shafts 52 to 54 is provided with an electric motor (not shown) via a gear (not shown). When the electric motor is driven, the corresponding drive shafts 52 to 54 rotate. It comes to move. When the drive shafts 52 to 54 are rotated, the connecting members 11 to 13 are relatively rotated via the drive shafts 52 to 54. In the wrist structure 1, the angle formed by the opening directions A <b> 1 and A <b> 2 of the one opening 11 a and the other opening 11 b is an obtuse angle, so that the second connecting member 12 is made relatively to the first connecting member 11. By turning, the direction of the second connecting member 12 can be changed in various directions. The wrist structure 1 is attached to the distal end portion of the arm 2a of the industrial robot 2 so that the distal end portion can be directed in various directions.

  Further, in the third drive shaft 54, the arm inner passage 2b is formed by the inner hole. The in-arm passage 2 b is connected to the first communication passage 14 a of the first connecting member 11. The first communication path 14 a is connected to the second communication path 16 a and the third communication path 13 a, and the wrist structure 1 is formed with a continuous communication path 1 a from the arm 2 a to the tip of the wrist structure 1. The communication path 1a accommodates a hose, a cable, and the like guided through the in-arm path 2b.

[Wrist structure assembly method]
Below, the assembly method of the wrist structure 1 which assembles the wrist structure 1 and attaches to the arm 2a is demonstrated, referring FIG.

  In step S1, which is a joint body assembly process, the joint body 15 is assembled. Specifically, first, the outer bearing member 25 is sandwiched by the two holding portions 21 a and 21 b of the outer annular member 21, and the two holding portions 21 a and 21 b are fastened by the bolts 24. Next, the central annular member 22 is disposed inside the outer bearing member 25, and the outer bearing member 25 is clamped by the first bevel gear 26 and the spacer portion 27. On the other hand, the inner bearing member 39 is disposed inside the central annular member 22, and the inner bearing member 39 is sandwiched between the first bevel gear 26 and the spacer portion 27. Thereafter, the bolt 19 is passed through the fastening hole 18, and the first bevel gear 26 and the spacer portion 27 are fastened by the bolt 19. Finally, the inner annular member 23 is disposed inside the inner bearing member 39, and the inner bearing member 39 is sandwiched between the two bevel gears 40 and 41. Thereby, the joint body 15 as shown in FIG. 3 is assembled, and the process proceeds to step S2.

  In step S2, which is a joint body attaching step, the joint body 15 is assembled to the first connecting member 11 as shown in FIG. More specifically, the first bevel gear 26 and the fourth bevel gear 41 of the joint body 15 are inserted from one opening 11 a of the first connecting member 11, and these bevel gears 26, 41 are inserted into the second communication space 43. To be located. Then, the outer annular member 21 and the first connecting member 11 are fastened by the bolt 24 that is brought into contact with the one open end 11 e of the first connecting member 11 and passed through the second through hole 30. When fastened, the wrist structure 1 has a shape as shown in FIG. 5, and the process proceeds to step S3.

  In step S3, which is the second connecting member assembling step, the second connecting member 12 is assembled to the first connecting member 11 via the joint body 15 as shown in FIG. More specifically, first, the third bevel gear 40 of the joint body 15 assembled to the first connecting member 11 is inserted from one opening 12a of the second connecting member 12, and the third bevel gear 40 is inserted into the first bevel gear 40. It is located in the communication space 38. Then, the spacer portion 27 of the central annular member 22 is brought into contact with one open end portion 12 c of the second connecting member 12. Accordingly, the second through hole 30 is covered by the flange portion 12d of the second connecting member 12. Next, the second connecting member 12 and the joint body 15 are positioned so that the portion of the first through hole 28 on the joint body 15 side is connected to the corresponding portion of the first through hole 28 on the second connecting member side. A plurality of first through holes 28 are formed. When the plurality of first through holes 28 are thus formed, the wrist structure 1 becomes a shape as shown in FIG. 6, and the process proceeds to step S4.

  In step S4 which is a fastening process, as shown in FIG. 7, the bolt 29 is inserted in the 1st through-hole 28, and the joint body 15 and the 2nd connection member 12 are fastened. Before describing a specific fastening method, the positions and postures of the plurality of first through holes 28 at the time of fastening will be described. The first through hole 28 extends in the axial direction of the joint body 15, that is, in the opening direction B1. Therefore, some of the plurality of first through holes 28 are formed regardless of the obtuse angle α formed by the opening direction A1 of the one opening 11a of the first connecting member 11 and the opening direction A2 of the other opening 11b. Only the other opening 11b is exposed in the extending direction (see FIGS. 6 and 7). On the other hand, the remaining first through hole 28 is hidden inside the first connecting member 11 without being exposed from the other opening 11b. Thus, the joint body 15 and the second connecting member 12 are screwed into the second connecting member 12 through bolts 29 to all of the plurality of first through holes 28 that are partially exposed and the remaining not exposed. The first connecting member 11 and the second connecting member 12 are connected via the joint body 15. Below, the fastening method is demonstrated in detail.

  First, a bolt 29 is passed through the first through hole 28 exposed from the other opening 11 b, and the bolt 29 is screwed into one opening end 12 c of the second connecting member 12. At this time, the first through hole 28 through which the bolt 29 is passed is exposed from the other opening portion 11b in the extending direction, so that it is outside the first connecting member 11 (outside the other opening portion 11b). Thus, the bolt 29 can be inserted straight into the first through hole 28, and a tool can be inserted straight when the bolt 29 is screwed into the second connecting member 12. Therefore, it is easy to put in a tool and work easily, and the connecting operation between the first connecting member and the second connecting member is easy.

  After passing the bolts 29 through all the first through holes 28 exposed in this way, the second connecting member 12 is rotated relative to the first connecting member 11 via the joint body 15. Then, the first through hole 28 through which the bolt 29 is passed is hidden inside the first connecting member 11, and another first through hole 28 hidden inside the first connecting member 11 moves to that position and moves to them. Appears. The bolt 29 is passed through the first through hole 28 newly exposed in this way, and this bolt 29 is screwed into one open end 12 c of the second connecting member 12. By repeatedly performing the screwing operation and the relative rotation operation of the bolts 29, all the first through holes 28 are screwed into the second connecting member 12 through the bolts 29, and the joint body 15 is fastened to the second connecting member 12. can do. When the joint body 15 is fastened to the second connecting member 12 in this manner, the process proceeds to step S5.

  In step S <b> 5, which is a rotating member assembling step, the rotating member 34 is assembled to the bearing holding member 31. More specifically, the front end side bearing member 32 is externally fitted to the rotating member 34. Then, the two holding portions 31a and 31b of the bearing holding member 31 are attached to the tip side bearing member 32 so as to sandwich the fitted front end side bearing member 32 from both sides in the axial direction, and the two holding portions 31a, 31b is fastened by the bolt 33, and the front end side bearing member 32 is held by the bearing holding member 31. The front end side bearing member 32 may be held by the bearing holding member 31 before the front end side bearing member 32 is externally fitted to the rotating member 34.

  In step S6, which is the third connecting member assembly step, the third connecting member 13 is attached to the second connecting member 12 as shown in FIG. Specifically, first, the base end of the rotating member 34 assembled to the bearing holding member 31 in step S5 is inserted from the opening 12b of the second connecting member 12, and the second bevel gear 37 is moved to the first bevel gear 37. It is located in the communication space 38. Then, the bearing holding member 31 is brought into contact with the opening end portion 12 e of the second connecting member 12, and the bearing holding member 31 and the second connecting member 12 are fastened by the bolt 33 passed through the third through hole 36. Thereafter, the base end portion of the third connecting member 13 is inserted into the bearing holding member 31, the third through hole 36 is covered by the flange portion 13 b of the third connecting member 13, and the third connecting member 13 is rotated by the bolt 35. Fastened to the tip of the moving member 34. Thereby, the front end side bearing member 32 is clamped by the third connecting member 13 and the rotating member 34, and the third connecting member 13 is connected to the second end via the rotating member 34, the front end side bearing member 32 and the bearing holding member 31. It is assembled to the connecting member 12. When assembled in this manner, the wrist structure 1 is completed, and the process proceeds to step S7.

  In step S7, which is an arm attachment process, the completed wrist structure 1 is attached to the arm 2a (see FIG. 2). More specifically, first, the tooth portions 53a and 54a at the tip portions of the second and third drive shafts 53 and 54 of the arm 2a are inserted into one opening portion 11a of the first connecting member 11, and the tooth portion 53a. , 54 a are positioned in the second communication space 43 and meshed with the first bevel gear 26 and the fourth bevel gear 41 that are similarly positioned in the second communication space 43. And the front-end | tip part of the 1st drive shaft 52 is made to contact | abut with the other opening end part 11d of the 1st connection member 11, and the front-end | tip part of the 1st drive shaft 52 and the other opening end part 11d of the 1st connection member 11 are contacted. Conclude. Thereby, the wrist structure 1 is assembled | attached to the arm 2a so that the 1st connection member 11, the 2nd connection member 12, and the 3rd connection member 13 can rotate mutually independently.

  In the wrist structure 1 assembled and attached by such an assembling method, the first through hole 28, the second through hole 30, the third through hole 36, and the like are not exposed to the outside. As shown in FIG. 9, the unevenness of the outer surface can be reduced. Such a wrist structure 1 can be easily assembled and attached to the arm 2a by the assembling method described above. Further, since the wrist structure 1 is assembled from the front end side, the wrist structure 1 can be assembled first separately from the robot 2, so that the time for mounting the robot 2 on the arm 2 a can be shortened.

[Other embodiments]
In the above-described embodiment, the three cylindrical connecting members 11 to 13 are configured to be connected in order from the base end to the tip end of the arm. However, the connection structure itself of the three cylindrical connection members 11 to 13 has no directionality. Therefore, for example, the three cylindrical connecting members 11 to 13 may be configured to be sequentially connected from the distal end of the arm toward the proximal end, except for the structure for transmitting the rotational driving force. Further, for example, the third connecting member 13 may be attached to the second connecting member 12 in advance, and the second connecting member 12 may be connected to the joint body 15 attached to the first connecting member 11 in this order. . However, in this case, the rotational driving force transmission structure is configured such that the rotational driving force is transmitted from the proximal end of the arm toward the distal end, and the three cylindrical connecting members 11 to 13 are connected to the arm. Needless to say, the structure is appropriately modified, such as being configured to become thinner in order from the proximal end to the distal end.

DESCRIPTION OF SYMBOLS 1 Wrist structure 1a Communication path 2 Robot 2a Arm 11 1st connection member 11a One opening part 11b The other opening part 11e One opening edge part 12 2nd connection member 12a One opening part 12b The other opening part 12c The other opening End portion 12d Flange portion 13 Third connecting member 13b Flange portion 15 Joint body 21 Outer annular member 22 Central annular member 23 Inner annular member 24 Bolt 26 First bevel gear 26a Tooth portion
28 1st through-hole 29 Bolt 30 2nd through-hole 31 Bearing holding member 33 Bolt 34 Rotating member 35 Bolt 36 3rd through-hole 41 4th bevel gear 41a Tooth part

Claims (6)

A wrist structure for an industrial robot attached to the tip of an arm and having a continuous path from the arm to the tip,
A first connecting member formed in a cylindrical shape;
An annular fixing member fixed to one opening end of the first connecting member, and an articulation body having an annular first rotating member rotatably provided inside the fixing member;
A second connecting member formed in a cylindrical shape and fastened to the first rotating member of the joint body so that the inner space thereof is connected to the inner space of the first connecting member;
A first fastening member for fastening the first rotating member and the second connecting member;
A bottomed first through hole reaching the second connecting member from the first rotating member is formed in the first rotating member and the second connecting member,
The wrist structure of the industrial robot, wherein the first fastening member is passed through the first through hole from the first rotating member side. The first connecting member is formed such that an angle formed by the opening direction of the one opening and the other opening different from the one opening is an obtuse angle.
A plurality of the first through holes are formed in the first rotating member and the second connecting member,
The plurality of first through holes extend in a predetermined direction from the second connecting member,
The first connecting member is formed such that only a part of the first through-holes of the plurality of first through-holes is exposed from the other opening toward the predetermined direction, and the second connecting member The wrist structure of the industrial robot according to claim 1, wherein the plurality of first through holes are sequentially exposed by rotating the frame relative to the first connecting member. A second rotating member rotatably provided inside the first rotating member;
A third connecting member that is formed in a cylindrical shape, is rotatably provided on the second connecting member so that its internal space is connected to the internal space of the second connecting member, and rotates in conjunction with the second rotating member. When,
A rotation drive unit for rotating the first rotation member and the second rotation member;
The first rotation member has a first gear portion to which power from the rotation drive unit is transmitted,
The second rotation member has a second gear portion to which power from the rotation drive unit is transmitted,
The wrist structure of the industrial robot according to claim 1 or 2, wherein the first fastening member is disposed between the first gear portion and the second gear portion. A second fastening member for fastening and fixing the fixing member to the first connecting member;
The fixed member and the first connecting member are formed with a bottomed second through hole that reaches from the fixing member to one opening of the first connecting member,
The wrist structure of the industrial robot according to any one of claims 1 to 3, wherein the second connecting member has a covering portion that covers the second through hole. A wrist structure for an industrial robot that is attached to the tip of an arm and has a continuous path from the arm to the tip of the arm. The first connection member formed in a cylindrical shape, and one of the first connection members An annular fixing member fixed to the opening end, an articulation body having an annular first rotating member rotatably provided inside the fixing member, and a cylindrical shape, and an internal space thereof A second connecting member fastened to the first rotating member of the joint body so as to be connected to the internal space of the first connecting member, and a first fastening member for fastening the first rotating member and the second connecting member The first rotating member and the second connecting member are formed with a bottomed first through hole that reaches the second connecting member from the first rotating member, and the first fastening member is The industrial passage passed through the first through hole from the first rotating member side In the method of assembling the wrist structure of the bot,
A fastening step of fastening the first turning member and the second connecting member through the first fastening member through a first through hole of the first turning member of the joint body fixed to the first connecting member;
A method for assembling the wrist structure of an industrial robot, comprising: a connecting step of connecting the first connecting member to a tip of the arm after the fastening step. The method for assembling the wrist structure according to claim 5,
The first connecting member is formed such that an angle formed by the opening direction of the one opening and the other opening different from the one opening is an obtuse angle.
A plurality of the first through holes are formed in the first rotating member and the second connecting member,
The plurality of first through holes extend in a predetermined direction from the second connecting member,
The first connecting member is formed such that only a part of the first through-holes of the plurality of first through-holes is exposed from the other opening toward the predetermined direction,
In the fastening step, the second connecting member is rotated relative to the first connecting member to sequentially expose the plurality of first through holes, and the first fastening holes are exposed to the first fastening holes. A method for assembling a wrist structure for an industrial robot, wherein members are sequentially passed to fasten the first rotating member and the second connecting member.

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