Industrial robot hand and industrial robot

Abstract

To provide an industrial robot hand in which a fork can be easily attached / detached to / from a hand base part in the industrial robot hand equipped with the fork and the hand base part to which the fork is attached.SOLUTION: In a hand, a fork fixing mechanism 52 for fixing a fork base end part 19a to a hand base part 17 includes: a bolt member 53 which is inserted in a bolt insertion hole 19b penetrating the fork base end part 19a and is engaged with a screw hole 40a formed in the hand base part 17; a spring member 54 for energizing the bolt member 53 with respect to the fork base end part 19a; and a come-off preventive member 55 preventing coming off of the bolt member 53 from the bolt insertion hole 19b. The come-off preventive member 55 is attached to the bolt member 53 and, when the bolt member 53 leaves the screw hole 40a, comes into contact with the fork distal end 19a to prevent the bolt member 53 from coming off the bolt insertion hole 19b.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a hand of an industrial robot that transports an object to be transported, and also to an industrial robot equipped with the hand. [Background technology]

[0002] Conventionally, industrial robots that transport glass substrates for liquid crystal displays are known (see, for example, Patent Document 1). The industrial robot described in Patent Document 1 includes a hand on which a glass substrate is mounted, an arm to which the hand is rotatably connected, and a main body that supports the arm. The hand includes a base that is rotatably connected to the tip side of the arm, and four forks on whose upper surfaces the glass substrate is placed. The base ends of the forks are disposed inside the base that is formed in a hollow shape. A fork pitch changing mechanism that changes the pitch of the four forks is disposed inside the base.

[0003] In the industrial robot described in Patent Document 1, the fork pitch changing mechanism includes a motor, a screw member connected to the output shaft of the motor, a slide member fixed to the base end of the fork, and a nut member attached to the slide member and engaging with the screw member. Since the hand of this industrial robot is equipped with a fork pitch changing mechanism that changes the pitch of the four forks, it is possible to transport glass substrates of various sizes. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2019-10693 A Summary of the Invention [Problem to be solved by the invention]

[0005] There is a need to transport smaller glass substrates using the industrial robot described in Patent Document 1. When glass substrates become smaller, the container for the glass substrate, such as a cassette, may become smaller. When the container for the glass substrate becomes smaller, it may become impossible to insert four forks into the container for the glass substrate. In this case, for example, two of the four forks may be removed and the remaining two forks may be inserted into the container for the glass substrate. On the other hand, when a large glass substrate is transported using the industrial robot described in Patent Document 1, if there are no four forks, the glass substrate placed on the forks may be greatly bent, which may cause a problem in transporting the glass substrate.

[0006] Therefore, in order to enable the transport of glass substrates of various sizes, including smaller glass substrates, using the industrial robot described in Patent Document 1, it becomes necessary to attach and detach the fork. When attaching and detaching the fork to the industrial robot described in Patent Document 1, it is preferable that the work of attaching and detaching the fork be easy.

[0007] Therefore, an object of the present invention is to provide an industrial robot hand that includes a fork and a hand base to which the fork is attached, and that allows the fork to be easily attached to and detached from the hand base. Another object of the present invention is to provide an industrial robot that includes this hand. [Means for solving the problem]

[0008] In order to solve the above problems, the hand of an industrial robot of the present invention is an industrial robot hand that transports an object to be transported, and comprises a fork formed in a straight line, a hand base to which the fork is attached, and a fork fixing mechanism for fixing the fork base end, which is the base end of the fork, to the hand base, wherein the fork base end is formed with a bolt insertion hole penetrating the fork base end, and the hand base is formed with a screw hole, and the fork fixing mechanism comprises a bolt member that is inserted into the bolt insertion hole and engages with the screw hole, a spring member for urging the bolt member to one side in the penetration direction of the bolt insertion hole relative to the fork base end, and a pull-out prevention member for preventing the bolt member from coming out of the bolt insertion hole, and a male thread is formed at a tip end of the bolt member which engages with the female thread of the screw hole, and the spring member urges the bolt member in a direction away from the screw hole, and the pull-out prevention member is attached to the bolt member, and when the male thread of the bolt member comes out of the female thread of the screw hole, The force of the spring member At the base end of the fork Always The contact prevents the bolt member from coming out of the bolt insertion hole. In the present invention, for example, the bolt member is a headed bolt consisting of a head and a shank, the anti-pullout member is attached to the shank, and the spring member biases the bolt member toward the side of the shank where the head is located, so that when the male threads of the bolt member come out of the female threads of the screw hole, the entire head is located within the bolt insertion hole and does not protrude from the base end of the fork.

[0009] In the hand of an industrial robot of the present invention, the fork fixing mechanism for fixing the fork base end to the hand base includes a bolt member that is inserted into a bolt insertion hole that passes through the fork base end and engages with a threaded hole formed in the hand base, a spring member that urges the bolt member to one side in the direction in which the bolt insertion hole passes through the fork base end, and a retaining member for preventing the bolt member from coming out of the bolt insertion hole. Also, in the present invention, the retaining member is attached to the bolt member and comes into contact with the fork base end to prevent the bolt member from coming out of the bolt insertion hole when the male thread of the bolt member comes out of the female thread of the threaded hole, so that the bolt member will not come out of the bolt insertion hole of a fork removed from the hand base.

[0010] Therefore, in the present invention, it is possible to handle the bolt member together with the fork removed from the hand base. Therefore, in the present invention, it is possible to eliminate the need to remove the bolt member from the bolt insertion hole and store it in the bolt member storage section when removing the fork from the hand base, and it is possible to eliminate the need to separately prepare the bolt member when attaching the fork to the hand base. As a result, in the present invention, it is possible to easily attach and detach the fork to and from the hand base.

[0011] In the present invention, it is preferable that the bolt insertion hole penetrates in the vertical direction, the bolt member is formed with a first positioning portion for determining the position of the bolt member in the horizontal direction relative to the fork base end and a second positioning portion for determining the position of the bolt member in the horizontal direction relative to the hand base, the bolt insertion hole is formed with a fork base end side positioning portion that contacts the first positioning portion to determine the position of the bolt member in the horizontal direction relative to the fork base end, and the hand base is formed with a hand base side positioning portion that contacts the second positioning portion to determine the position of the bolt member in the horizontal direction relative to the hand base. With this configuration, when attaching the fork to the hand base, the horizontal positioning of the fork base end relative to the hand base can be easily performed via the bolt member. Therefore, the work of attaching the fork to the hand base can be performed more easily.

[0012] In the present invention, it is preferable that the spring member is a compression coil spring into which the bolt member is inserted, the retaining member is a retaining ring, and the bolt member is formed with a retaining ring engagement groove into which the retaining ring fits. With this configuration, it is possible to prevent the bolt member from coming out of the bolt insertion hole of the fork removed from the hand base with a relatively simple configuration. In other words, even if it is possible to prevent the bolt member from coming out of the bolt insertion hole of the fork removed from the hand base, it is possible to simplify the configuration of the fork fixing mechanism.

[0013] In the present invention, the hand, for example, includes a plurality of forks arranged parallel to each other, and the hand base includes a fork pitch change mechanism that changes the pitch of the multiple forks in an orthogonal direction perpendicular to the longitudinal direction and the up-down direction of the forks, and the fork pitch change mechanism includes a feed screw shaft, a nut member that engages with the feed screw shaft, and a slide member to which the nut member is attached, and the fork base end is fixed to the slide member by the fork fixing mechanism.

[0014] In the present invention, if the direction perpendicular to the longitudinal direction and the up-down direction of the forks is defined as the orthogonal direction, the hand includes, for example, two forks arranged parallel to each other and two linear second forks arranged between the two forks in the orthogonal direction and parallel to the forks. When transporting a small object with an industrial robot, it is possible to transport the object to a smaller storage section for the object if the forks are removed from the hand base rather than removing the second fork arranged between the two forks in the orthogonal direction from the hand base. Therefore, when transporting a small object with an industrial robot, it is preferable to remove the forks from the hand base, but in the present invention, even if the forks are removed from the hand base, the work of attaching and detaching the forks to and from the hand base can be easily performed.

[0015] The hand of the present invention can be used in an industrial robot having an arm to which the hand is rotatably connected at its tip end and a main body to which the base end of the arm is rotatably connected. With this industrial robot, it becomes easy to attach and detach a fork to and from the hand base. Effect of the Invention

[0016] As described above, the present invention makes it possible to easily attach and detach the fork to and from the hand base in an industrial robot hand that has a fork and a hand base to which the fork is attached. [Brief description of the drawings]

[0017] [Figure 1] 1 is a plan view of an industrial robot according to an embodiment of the present invention; [Diagram 2] FIG. 2 is a side view of the industrial robot shown in FIG. [Diagram 3] 2 is a plan view for explaining the structure of a hand base of the hand shown in FIG. 1. [Figure 4] FIG. 4 is an enlarged view of part E in FIG. [Diagram 5] 5 is a cross-sectional view for explaining the configuration of the FF cross section of FIG. 4. [Figure 6] 6 is a cross-sectional view for explaining the configuration of the cross section GG of FIG. 5. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0019] (Overall configuration of industrial robots) Fig. 1 is a plan view of an industrial robot 1 according to an embodiment of the present invention, and Fig. 2 is a side view of the industrial robot 1 shown in Fig. 1.

[0020] The industrial robot 1 (hereinafter referred to as "robot 1") of this embodiment is a horizontal articulated robot for transporting a predetermined transport object 2. The transport object 2 is, for example, a glass substrate for a liquid crystal display. The transport object 2 is formed in a rectangular flat plate shape. The robot 1 of this embodiment is capable of transporting transport objects 2 of various sizes.

[0021] The robot 1 includes two hands 3 on which a transport target 2 is placed, two arms 4 to which the tips of the two hands 3 are connected, a main body 5 supporting the two arms 4, and a base 6 supporting the main body 5 so as to be movable in the horizontal direction. The main body 5 includes an arm support 7 that supports the base end of the arm 4 and is vertically movable, a support frame 8 that supports the arm support 7 so as to be vertically movable, a base 9 that constitutes the lower end portion of the main body 5 and is horizontally movable relative to the base 6, and a rotating frame 10 to which the lower end of the support frame 8 is fixed and is rotatable relative to the base 9.

[0022] The arm 4 is composed of two arm sections, a first arm section 12 and a second arm section 13. The base end side of the first arm section 12 is rotatably connected to the arm support 7. That is, the base end side of the arm 4 is rotatably connected to the main body section 5. The base end side of the second arm section 13 is rotatably connected to the tip side of the first arm section 12. The hand 3 is rotatably connected to the tip side of the second arm section 13. That is, the hand 3 is rotatably connected to the tip side of the arm 4. The robot 1 has two arm drive mechanisms that extend and retract each of the two arms 4.

[0023] The base end side of one of the two arms 4 is rotatably connected to the upper end of the arm support 7. The base end side of the other arm 4 is rotatably connected to the lower end of the arm support 7, and the other arm 4 is disposed below the other arm 4. In the one arm 4 disposed on the upper side, the second arm section 13 is disposed below the first arm section 12, and the hand 3 is disposed below the second arm section 13. In the other arm 4 disposed on the lower side, the second arm section 13 is disposed above the first arm section 12, and the hand 3 is disposed above the second arm section 13.

[0024] The support frame 8 holds the hand 3 and the arm 4 via the arm support 7 so that they can be raised and lowered. The support frame 8 includes a columnar first support frame 14 that holds the arm support 7 so that it can be raised and lowered, and a columnar second support frame 15 that holds the first support frame 14 so that it can be raised and lowered. The robot 1 includes an elevation mechanism that raises and lowers the arm support 7 relative to the first support frame 14, an elevation mechanism that raises and lowers the first support frame 14 relative to the second support frame 15, a guide mechanism that guides the first support frame 14 in the up and down direction, and a guide mechanism that guides the arm support 7 in the up and down direction.

[0025] The lower end of the second support frame 15 is fixed to the swivel frame 10. As described above, the swivel frame 10 is rotatable relative to the base 9. The robot 1 is provided with a rotation mechanism that rotates the swivel frame 10 relative to the base 9. As described above, the base 9 is horizontally movable relative to the base 6. The robot 1 is provided with a horizontal movement mechanism that horizontally moves the base 9 relative to the base 6.

[0026] (Overall composition of the hand) FIG. 3 is a plan view for explaining the structure of the hand base 17 of the hand 3 shown in FIG. 1. FIG. 4 is an enlarged view of part E in FIG. 3. FIG. 5 is a cross-sectional view for explaining the configuration of the FF section in FIG. 4. FIG. 6 is a cross-sectional view for explaining the configuration of the GG section in FIG. 5. In the following explanation, the configuration of the hand 3 connected to the arm 4 arranged on the lower side will be explained. Note that the configuration of the hand 3 connected to the arm 4 arranged on the upper side is the same as the configuration of the hand 3 described below, which is upside down.

[0027] The hand 3 includes a hand base 17 rotatably connected to the tip side of the second arm portion 13, and a plurality of forks 18, 19 formed in a straight line and having the transport object 2 placed on the upper surface thereof. The hand 3 in this embodiment includes a total of four forks 18, 19: two forks 18 and two forks 19. The forks 18, 19 are attached to the hand base 17. Specifically, fork base ends 18a, 19a, which are the base ends of the forks 18, 19, are attached to the hand base 17.

[0028] The four forks 18, 19 protrude in the same horizontal direction from the hand base 17. The four forks 18, 19 are arranged parallel to one another. That is, two forks 18 are arranged parallel to one another, and two forks 19 are arranged parallel to one another, and two forks 18 and two forks 19 are arranged parallel to one another.

[0029] If the longitudinal direction of the forks 18, 19 (X direction in FIG. 3, etc.) is defined as the "front-rear direction" and the Y direction in FIG. 3, etc., which is perpendicular to the up-down direction and the front-rear direction, is defined as the "left-right direction," the two forks 18 are disposed inside in the left-right direction, and the two forks 19 are disposed outside in the left-right direction. The left-right direction (Y direction) in this embodiment is an orthogonal direction perpendicular to the longitudinal direction and the up-down direction of the forks 18, 19. Also, the fork 18 in this embodiment is a second fork disposed between the two forks 19 in the left-right direction.

[0030] The hand base 17 is formed into a flat, generally rectangular parallelepiped shape with a thin thickness in the up-down direction as a whole. The hand base 17 includes a base frame 22 constituting the lower end side portion of the hand base 17, and a cover 23 (see FIG. 5) fixed to the base frame 22. The hand base 17 also includes a fork pitch changing mechanism 26 that changes the pitch of the two forks 18 in the left-right direction, and a fork pitch changing mechanism 27 that changes the pitch of the two forks 19 in the left-right direction (see FIG. 3). The fork pitch changing mechanisms 26, 27 are disposed in the internal space of the hand base 17 defined by the base frame 22 and the cover 23.

[0031] In the fork pitch change mechanism 26, one fork 18 and the other fork 18 of the two forks 18 move the same amount in opposite left and right directions to change the left and right pitch of the two forks 18. Similarly, in the fork pitch change mechanism 27, one fork 19 and the other fork 19 move the same amount in opposite left and right directions to change the left and right pitch of the two forks 19. The fork pitch change mechanisms 26, 27 change the left and right pitch of the forks 18, 19 depending on the size of the transport object 2 transported by the robot 1.

[0032] The fork pitch change mechanism 26 includes a motor 29 as a drive source, a feed screw shaft 30 connected to the output shaft of the motor 29, a slide member 31 to which the fork base end 18a of one of the two forks 18 is attached, a slide member 31 to which the fork base end 18a of the other of the two forks 18 is attached, and two nut members 32 (see Figure 5) that are attached to each of the two slide members 31 and engage with the feed screw shaft 30.

[0033] Similar to the fork pitch change mechanism 26, the fork pitch change mechanism 27 comprises a motor 34 as a drive source, a feed screw shaft 35 connected to the output shaft of the motor 34, a slide member 36 to which the fork base end 19a of one of the two forks 19 is attached, a slide member 36 to which the fork base end 19a of the other of the two forks 19 is attached, and two nut members 37 (see Figure 5) that are attached to each of the two slide members 36 and engage with the feed screw shaft 35.

[0034] The feed screw shafts 30 and 35 are formed in a long and thin rod shape. The feed screw shafts 30 and 35 are arranged so that the axial direction of the feed screw shafts 30 and 35 coincides with the left-right direction, and rotate with the left-right direction as the axial direction of the rotation. The feed screw shafts 30 and 35 are arranged with a predetermined gap in the front-rear direction. The feed screw shafts 30 and 35 are provided with forward thread portions 30a and 35a constituting one end side of the feed screw shafts 30 and 35, and reverse thread portions 30b and 35b constituting the other end side of the feed screw shafts 30 and 35. The forward thread portions 30a and 35a are formed with forward threads, and the reverse thread portions 30b and 35b are formed with reverse threads.

[0035] The slide members 31 and 36 are formed in a generally flat rectangular parallelepiped shape with a thin thickness in the vertical direction. A fixing member 40 is fixed to the upper surface of the slide member 36. That is, the hand base 17 includes a fixing member 40 fixed to the upper surface of the slide member 36. The fixing member 40 is fixed to the slide member 36 by a bolt 41. The fixing member 40 is formed in a flat rectangular parallelepiped shape with a thin thickness in the vertical direction. The fixing member 40 is also formed in a rectangular parallelepiped shape that is elongated in the front-rear direction. Similarly, a rectangular parallelepiped fixing member (not shown) is fixed to the upper surface of the slide member 31. The nut member 32 is attached to the slide member 31 by a bolt, and the nut member 37 is attached to the slide member 36 by a bolt.

[0036] A nut member 32 held by a slide member 31 to which the fork base end 18a of one of the two forks 18 is fixed engages with the forward thread portion 30a, and a nut member 32 held by a slide member 31 to which the fork base end 18a of the other fork 18 is fixed engages with the reverse thread portion 30b. A nut member 37 held by a slide member 36 to which the fork base end 19a of one of the two forks 19 is fixed engages with the forward thread portion 35a, and a nut member 37 held by a slide member 36 to which the fork base end 19a of the other fork 19 is fixed engages with the reverse thread portion 35b.

[0037] The two slide members 31 and the two slide members 36 are guided in the left-right direction by two common guide rails 42. The guide rails 42 are fixed to the base frame 22 so that the longitudinal direction of the guide rails 42 coincides with the left-right direction. Two guide blocks 43 that engage with the two guide rails 42, respectively, are fixed to the slide member 31. Two guide blocks 43 that engage with the two guide rails 42, respectively, are fixed to the slide member 36.

[0038] The fork 18 includes a fork body 46 formed in a rectangular tubular shape elongated in the front-rear direction. The fork body 46 is formed of a resin containing carbon fiber. The upper surface of the fork body 46 is flat, and the transport target object 2 is placed on the upper surface side of the fork body 46. In this embodiment, the fork base end 18a is formed by the base end of the fork body 46. The fork base end 18a is disposed in the internal space of the hand base 17 defined by the base frame 22 and the cover 23. The fork base end 18a is fixed to the slide member 31. Specifically, the fork base end 18a is fixed to a fixing member fixed to the upper surface of the slide member 31, and is fixed to the slide member 31 via the fixing member. The fork base end 18a is also fixed to the upper surface of the fixing member by a bolt.

[0039] The fork 19 includes a fork body 47 configured similarly to the fork body 46. The fork body 47 is formed in a rectangular tube shape that is elongated in the front-rear direction, and the transport target object 2 is placed on the upper surface side of the fork body 47. The fork 19 also includes a rectangular parallelepiped base end member 48 that constitutes a part of the fork base end 19a, and a flat base plate 49 that constitutes a part of the fork base end 19a. In this embodiment, the fork base end 19a is formed by the base end of the fork body 47, the base end member 48, and the base plate 49.

[0040] The upper and lower surfaces of the base end of the fork body 47 are flat surfaces perpendicular to the up-down direction. The base end member 48 is formed in a rectangular parallelepiped shape elongated in the front-rear direction. The base end member 48 is made of an aluminum alloy. The base end member 48 is disposed inside the base end of the fork body 47, which is formed in a rectangular tube shape. As shown in FIG. 5, the base end member 48 is fixed to the base end of the fork body 47 by a bolt. The base plate 49 is formed in a rectangular flat plate shape with the long side direction being the front-rear direction. The base plate 49 is made of an aluminum alloy. As shown in FIG. 5, the base plate 49 is fixed to the lower surface of the base end of the fork body 47 by a bolt, and is disposed below the base end of the fork body 47. The thickness direction of the base plate 49 coincides with the up-down direction.

[0041] The fork base end 19a is disposed in an internal space of the hand base 17 defined by the base frame 22 and the cover 23. The fork base end 19a is fixed to the slide member 36. Specifically, the fork base end 19a is fixed to a fixing member 40 which is fixed to the upper surface of the slide member 36, and is fixed to the slide member 36 via the fixing member 40. The fork base end 19a is also fixed to the slide member 36 by a fork fixing mechanism 52. Specifically, the fork base end 19a is fixed to the upper surface of the fixing member 40 by the fork fixing mechanism 52.

[0042] That is, the hand 3 is equipped with a fork fixing mechanism 52 for fixing the fork base end 19a to the hand base 17, and the fork base end 19a is attached to the hand base 17 by the fork fixing mechanism 52. The configuration of the fork fixing mechanism 52 and the surrounding area thereof will be described below.

[0043] (Configuration of the fork fixing mechanism and the surrounding parts of the fork fixing mechanism) As described above, the fork base end 19a is fixed to the upper surface of the fixed member 40 by the fork fixing mechanism 52. In this embodiment, one fork base end 19a is fixed to the fixed member 40 by two fork fixing mechanisms 52. That is, the hand 3 is equipped with a total of four fork fixing mechanisms 52. The two fork fixing mechanisms 52 that fix one fork base end 19a to the fixed member 40 are arranged with a gap between them in the front-rear direction.

[0044] The fork fixing mechanism 52 includes a bolt member 53 that fixes the fork base end 19a to the fixing member 40. The fork base end 19a is formed with a bolt insertion hole 19b through which the bolt member 53 is inserted. The bolt insertion hole 19b penetrates the fork base end 19a. Specifically, the bolt insertion hole 19b penetrates the fork base end 19a in the up-down direction. That is, the up-down direction is the penetration direction of the bolt insertion hole 19b. The fixing member 40 is formed with a screw hole 40a with which the bolt member 53 engages. That is, the hand base 17 is formed with a screw hole 40a with which the bolt member 53 engages. In this embodiment, the fork base end 19a is fixed to the fixing member 40 by engaging the bolt member 53 with the screw hole 40a.

[0045] The fork fixing mechanism 52 also includes a spring member 54 for biasing the bolt member 53 toward one side in the penetration direction (i.e., the up-down direction) of the bolt insertion hole 19b relative to the fork base end 19a, and a retaining member 55 for preventing the bolt member 53 from coming out of the bolt insertion hole 19b. The spring member 54 is a compression coil spring on the inner periphery of which the bolt member 53 is disposed. The retaining member 55 is a retaining ring. Therefore, hereinafter, the spring member 54 will be referred to as the "compression coil spring 54" and the retaining member 55 as the "retaining ring 55". The retaining ring 55 in this embodiment is a C-shaped retaining ring.

[0046] The bolt member 53 is a headed bolt composed of a head 53a and a shaft portion 53b. A hexagonal recess is formed on the end surface of the head 53a. That is, the bolt member 53 is a hexagonal socket bolt. The bolt member 53 in this embodiment is a stripper bolt. The bolt member 53 is arranged so that the axial direction of the bolt member 53 coincides with the up-down direction. The head 53a is arranged on the upper side. The tip portion of the bolt member 53 (i.e., the lower end portion of the shaft portion 53b) is formed with a male thread that engages with the female thread of the screw hole 40a. That is, the tip portion of the bolt member 53 is a thread forming portion 53c in which a male thread is formed. If the portion of the shaft portion 53b other than the thread forming portion 53c is defined as a shaft portion main body 53d, the outer diameter of the thread forming portion 53c is smaller than the outer diameter of the shaft portion main body 53d.

[0047] The bolt member 53 is formed with a retaining ring engagement groove 53e into which a retaining ring 55 fits (see FIG. 6). The retaining ring engagement groove 53e is formed in the shaft main body 53d. The retaining ring engagement groove 53e is an annular recess recessed from the outer circumferential surface of the shaft main body 53d toward the inside in the radial direction of the shaft main body 53d. The retaining ring engagement groove 53e is formed below the center in the up-down direction of the shaft portion 53b.

[0048] The bolt insertion hole 19b is formed at both ends of the fork base end 19a in the front-rear direction. The bolt insertion hole 19b is also formed at the center of the fork base end 19a in the left-right direction. The bolt insertion hole 19b is composed of a through hole 47a formed in the upper surface of the fork body 47, a through hole 47b formed in the lower surface of the fork body 47, a through hole 48a formed in the base end member 48, and a through hole 49a formed in the base plate 49.

[0049] The through hole 47a is a round hole that passes through the upper surface of the fork body 47 in the vertical direction. The inner diameter of the through hole 47a is larger than the outer diameter of the head 53a of the bolt member 53. The through hole 47b is a round hole that passes through the lower surface of the fork body 47 in the vertical direction. The inner diameter of the through hole 47b is larger than the outer diameter of the head 53a. The inner diameter of the through hole 47b is also larger than the outer diameter of the retaining ring 55.

[0050] The through hole 48a penetrates the base end member 48 in the vertical direction. As shown in FIG. 6, the through hole 48a is composed of a large diameter hole 48b constituting the upper end of the through hole 48a, a medium diameter hole 48c constituting the vertical middle part of the through hole 48a, and a small diameter hole 48d constituting the lower end of the through hole 48a. The large diameter hole 48b, the medium diameter hole 48c, and the small diameter hole 48d are round holes. The inner diameter of the large diameter hole 48b is larger than the outer diameter of the head 53a of the bolt member 53. The inner diameter of the medium diameter hole 48c is smaller than the outer diameter of the head 53a. The inner diameter of the medium diameter hole 48c is larger than the outer diameter of the shaft body 53d and the outer diameter of the compression coil spring 54. The inner diameter of the small diameter hole 48d is approximately equal to the outer diameter of the shaft body 53d.

[0051] The through hole 49a is a round hole that passes through the base plate 49 in the up-down direction. The inner diameter of the through hole 49a is approximately equal to the outer diameter of the shaft body 53d. The axis of the large diameter hole 48b, the axis of the medium diameter hole 48c, and the axis of the small diameter hole 48d are aligned. In addition, the axis of the through hole 47a, the axis of the through hole 47b, the axis of the through hole 48a, and the axis of the through hole 49a are aligned.

[0052] 6A, when the fork base end 19a is fixed to the fixing member 40, a part of the shaft body 53d is disposed in the small diameter hole 48d and the through hole 49a. In this embodiment, the bolt member 53 is positioned in the horizontal direction relative to the fork base end 19a by the part of the shaft body 53d disposed in the small diameter hole 48d, the part of the shaft body 53d disposed in the through hole 49a, the small diameter hole 48d, and the through hole 49a.

[0053] In this embodiment, the portion of the shaft body 53d disposed in the small diameter hole 48d and the portion of the shaft body 53d disposed in the through hole 49a serve as a first positioning portion 53f for determining the position of the bolt member 53 in the horizontal direction relative to the fork base end 19a (see FIG. 6). Also, the inner circumferential surface of the small diameter hole 48d and the inner circumferential surface of the through hole 49a in this embodiment serve as a fork base end side positioning portion 19c that comes into contact with the first positioning portion 53f to determine the position of the bolt member 53 in the horizontal direction relative to the fork base end 19a (see FIG. 6).

[0054] The fixing member 40 has a placement hole 40b in which the lower end of the shaft body 53d is placed. That is, the hand base 17 has a placement hole 40b. The placement hole 40b is a round hole. The inner diameter of the placement hole 40b is approximately equal to the outer diameter of the shaft body 53d. The lower end of the placement hole 40b is connected to the upper end of the screw hole 40a, and the screw hole 40a is located directly below the placement hole 40b. The axis of the screw hole 40a and the axis of the placement hole 40b are aligned. The screw hole 40a and the placement hole 40b are formed at both ends of the fixing member 40 in the front-rear direction. Also, the screw hole 40a and the placement hole 40b are formed at the center of the fixing member 40 in the left-right direction.

[0055] 6(A), the lower end of the shaft body 53d is disposed in the arrangement hole 40b. In this embodiment, the bolt member 53 is positioned relative to the fixed member 40 in the horizontal direction by the portion of the shaft body 53d disposed in the arrangement hole 40b and the arrangement hole 40b. That is, in this embodiment, the bolt member 53 is positioned relative to the hand base 17 in the horizontal direction by the portion of the shaft body 53d disposed in the arrangement hole 40b and the arrangement hole 40b.

[0056] In this embodiment, the portion of the shaft main body 53d that is placed in the arrangement hole 40b serves as a second positioning portion 53g for determining the position of the bolt member 53 in the horizontal direction relative to the hand base 17 (see FIG. 6). Also, the inner circumferential surface of the arrangement hole 40b in this embodiment serves as a hand base side positioning portion 17a that comes into contact with the second positioning portion 53g to determine the position of the bolt member 53 in the horizontal direction relative to the hand base 17 (see FIG. 6).

[0057] The compression coil spring 54 is disposed in the large diameter hole 48b and the medium diameter hole 48c. The inner diameter of the compression coil spring 54 is larger than the outer diameter of the shaft body 53d. The outer diameter of the compression coil spring 54 is smaller than the outer diameter of the head 53a. The lower end of the compression coil spring 54 contacts a step surface formed at the boundary between the medium diameter hole 48c and the small diameter hole 48d. This step surface is an annular flat surface perpendicular to the up-down direction. The upper end of the compression coil spring 54 contacts the lower surface of the head 53a. The compression coil spring 54 biases the bolt member 53 upward. That is, the compression coil spring 54 biases the bolt member 53 in a direction in which the bolt member 53 moves away from the screw hole 40a.

[0058] The retaining ring 55 is attached to the bolt member 53. The retaining ring 55 is disposed in the through hole 47b. When the fork base end 19a is fixed to the fixing member 40, as shown in FIG. 6A, the retaining ring 55 is in contact with the upper surface of the base plate 49. However, when the fork base end 19a is fixed to the fixing member 40, a gap may be formed between the retaining ring 55 and the upper surface of the base plate 49. In this case, the step surface formed at the boundary between the threaded portion 53c and the shaft body 53d is in contact with the step surface formed at the boundary between the screw hole 40a and the arrangement hole 40b.

[0059] On the other hand, when fork base end 19a is removed from fixed member 40, as shown in Fig. 6(B), the urging force of compression coil spring 54 moves bolt member 53 upward relative to fork base end 19a, so that retaining ring 55 comes into contact with the underside of base end member 48. Also, when fork base end 19a is removed from fixed member 40, retaining ring 55 comes into contact with the underside of base end member 48, preventing bolt member 53 from coming out of bolt insertion hole 19b.

[0060] In this manner, when the bolt member 53 comes out of the screw hole 40a, the retaining ring 55 comes into contact with the underside of the base end member 48, thereby preventing the bolt member 53 from coming out of the bolt insertion hole 19b. That is, when the male thread of the bolt member 53 comes out of the female thread of the screw hole 40a, the retaining ring 55 comes into contact with the fork base end portion 19a, thereby preventing the bolt member 53 from coming out of the bolt insertion hole 19b. When the retaining ring 55 is in contact with the underside of the base end member 48, the upper end surface of the head 53a of the bolt member 53 is located below the upper surface of the fork body 47, and the head 53a does not protrude upward from the fork body 47.

[0061] In this embodiment, when the four forks 18, 19 can be inserted into the storage section in which the transport object 2 is stored, the robot 1 is used with two forks 19 attached to the hand base 17. On the other hand, when the size of the transport object 2 to be transported by the robot 1 is small and the four forks 18, 19 cannot be inserted into the storage section, the two forks 19 are removed from the fixing member 40.

[0062] When removing the fork 19, the cover 23 is removed, and the bolt members 53 engaged with the screw holes 40a are loosened from above to remove the fork 19. At this time, the fork 19 is moved toward the tip side of the fork 19 to remove it. For example, a predetermined serial number is engraved on the fork base end portion 19a and the slide member 36 so that the fork 19 is fixed to the same slide member 36 when the removed fork 19 is fixed to the slide member 36 again.

[0063] (Main effects of this form) As described above, in this embodiment, the fork fixing mechanism 52 includes the bolt member 53 that fixes the fork base end 19a to the hand base 17, the compression coil spring 54 that biases the bolt member 53 against the fork base end 19a, and the retaining ring 55 attached to the bolt member 53. Also, in this embodiment, when the bolt member 53 comes out of the screw hole 40a of the hand base 17, the retaining ring 55 comes into contact with the fork base end 19a by the biasing force of the compression coil spring 54 to prevent the bolt member 53 from coming out of the bolt insertion hole 19b, and when the fork base end 19a is removed from the hand base 17, the bolt member 53 does not come out of the bolt insertion hole 19b of the fork 19.

[0064] Therefore, in this embodiment, it is possible to handle the bolt member 53 together with the fork 19 removed from the hand base 17. Therefore, in this embodiment, it is possible to eliminate the need to remove the bolt member 53 from the bolt insertion hole 19b and accommodate it in the accommodation portion of the bolt member 53 when removing the fork 19 from the hand base 17, and it is possible to eliminate the need to separately prepare the bolt member 53 when attaching the fork 19 to the hand base 17. As a result, in this embodiment, it is possible to easily attach and detach the fork 19 to the hand base 17.

[0065] Furthermore, when the robot 1 transports a small object 2, it is possible to transport the object 2 to a smaller storage section for the object 2 if the two forks 19 arranged on the outside in the left-right direction are removed from the hand base 17 rather than removing the two forks 18 arranged on the inside in the left-right direction from the hand base 17, so it is preferable to remove the forks 19 when transporting a small object 2 with the robot 1, but in this embodiment, the fork base end 19a of the fork 19 is attached to the hand base 17 by the fork fixing mechanism 52. Therefore, in this embodiment, even when the forks 19 are removed from the hand base 17, the forks 19 can be easily attached and detached to and from the hand base 17.

[0066] In this embodiment, the bolt member 53 is positioned in the horizontal direction relative to the fork base end 19a by the first positioning portion 53f of the bolt member 53 and the small diameter hole 48d and through hole 49a of the fork base end 19a, and the bolt member 53 is positioned in the horizontal direction relative to the hand base 17 by the second positioning portion 53g of the bolt member 53 and the arrangement hole 40b of the hand base 17. Therefore, in this embodiment, when attaching the fork 19 to the hand base 17, the fork base end 19a can be easily positioned in the horizontal direction relative to the hand base 17 via the bolt member 53. Therefore, in this embodiment, the attachment work of the fork 19 to the hand base 17 can be performed more easily.

[0067] In this embodiment, the compression coil spring 54 and the retaining ring 55 are used to prevent the bolt member 53 from coming out of the bolt insertion hole 19b of the fork 19 removed from the hand base 17. Therefore, in this embodiment, it is possible to prevent the bolt member 53 from coming out of the bolt insertion hole 19b of the fork 19 removed from the hand base 17 with a relatively simple configuration. That is, in this embodiment, even if it is possible to prevent the bolt member 53 from coming out of the bolt insertion hole 19b of the fork 19 removed from the hand base 17, it is possible to simplify the configuration of the fork fixing mechanism 52.

[0068] (Other embodiments) The above-described embodiment is one example of a preferred embodiment of the present invention, but the present invention is not limited to this embodiment and various modifications can be made without departing from the spirit and scope of the present invention.

[0069] In the above-described embodiment, the two forks 19 may be disposed on the inner side in the left-right direction, and the two forks 18 may be disposed on the outer side in the left-right direction. That is, the two forks 19 may be disposed between the two forks 18 in the left-right direction. In addition, in the above-described embodiment, at least one of the two forks 19 may be fixed in the left-right direction. In this case, the fork base end portion 19a of the fork 19 fixed in the left-right direction is fixed to the base frame 22 by, for example, the fork fixing mechanism 52. In the above-described embodiment, at least one of the two forks 18 may be fixed in the left-right direction.

[0070] In the above-described embodiment, the number of forks 18 included in the hand 3 may be one or three or more. Also, in the above-described embodiment, the number of forks 19 included in the hand 3 may be one or three or more. Furthermore, in the above-described embodiment, the spring member 54 for biasing the bolt member 53 may be a spring member other than a compression coil spring. Also, the retaining member 55 for preventing the bolt member 53 from coming out of the bolt insertion hole 19b may be a retaining ring other than a C-shaped retaining ring, or may be a member other than a retaining ring.

[0071] In the above embodiment, the hand 3 may be provided with a positioning portion for performing horizontal positioning of the fork base end 19a relative to the hand base 17. In this case, for example, the inner diameter of the small diameter hole 48d, the inner diameter of the through hole 49a, and the inner diameter of the arrangement hole 40b are larger than the outer diameter of the shaft body 53d. Also, in the above embodiment, the bolt insertion hole 19b may penetrate the fork base end 19a in the left-right direction. In this case, for example, the fixing member 40 is arranged on one side of the fork base end 19a in the left-right direction, and the fork base end 19a is fixed to the fixing member 40 arranged on one side of the fork base end 19a in the left-right direction by the bolt member 53.

[0072] In the embodiment described above, the robot 1 is a horizontal articulated robot, but the robot to which the present invention is applied may be an industrial robot other than a horizontal articulated robot. For example, the robot to which the present invention is applied may be provided with a sliding mechanism that linearly slides the hand 3 instead of the arm 4. [Explanation of symbols]

[0073] 1. Robots (industrial robots) 2. Transported objects 3 Hands 4 Arm 5 Main body 17 Hand base 17a Hand base side positioning part 18 Fork (2nd Fork) 19. Fork 19a Fork base end 19b Bolt insertion hole 19c Fork base end side positioning part 27 Fork pitch change mechanism 35 Feed screw shaft 36 Slide member 37 Nut material 40a screw hole 52 Fork fixing mechanism 53 Bolt parts 53e Retaining ring engagement groove 53f First positioning part 53g Second positioning part 54 Compression coil spring (spring component) 55 Retaining ring (prevention member) X Longitudinal direction of fork Y orthogonal direction

Claims

1. In an industrial robot hand that transports objects, a fork formed in a straight line, a hand base to which the fork is attached, and a fork fixing mechanism for fixing a fork base end, which is a base end of the fork, to the hand base, The fork base end is formed with a bolt insertion hole passing through the fork base end, The hand base is provided with a screw hole, the fork fixing mechanism includes a bolt member that is inserted into the bolt insertion hole and engages with the threaded hole, a spring member that biases the bolt member toward one side in a direction in which the bolt insertion hole penetrates the fork base end, and a retaining member that prevents the bolt member from coming out of the bolt insertion hole, A male thread is formed at a tip end of the bolt member to engage with the female thread of the screw hole, the spring member biases the bolt member in a direction away from the screw hole, The anti-pullout member is attached to the bolt member, and when the male threads of the bolt member come out of the female threads of the screw hole, the spring force of the spring member keeps the anti-pullout member in constant contact with the base end of the fork to prevent the bolt member from coming out of the bolt insertion hole.

2. The bolt member is a headed bolt composed of a head and a shaft, The retaining member is attached to the shaft portion, the spring member biases the bolt member toward a side of the shaft portion where the head is disposed, 2. The hand according to claim 1, wherein when the male threads of the bolt member are disengaged from the female threads of the screw hole, the entire head is disposed within the bolt insertion hole and the head does not protrude from the base end of the fork.

3. The bolt insertion hole extends in an up-down direction. the bolt member is formed with a first positioning portion for determining a position of the bolt member in a horizontal direction relative to the fork base end portion, and a second positioning portion for determining a position of the bolt member in a horizontal direction relative to the hand base portion, a fork base end side positioning portion that contacts the first positioning portion and determines a horizontal position of the bolt member relative to the fork base end portion is formed in the bolt insertion hole; 3. The hand according to claim 1, wherein the hand base is formed with a hand base side positioning portion that contacts the second positioning portion to determine a horizontal position of the bolt member relative to the hand base.

4. the spring member is a compression coil spring into which the bolt member is inserted on its inner circumferential side, The retaining member is a retaining ring, 4. The hand according to claim 1, wherein the bolt member is formed with a retaining ring engagement groove into which the retaining ring fits.

5. A plurality of the forks are arranged parallel to each other, The hand base includes a fork pitch change mechanism that changes the pitch of the forks in a direction perpendicular to the longitudinal direction and the up-down direction of the forks, The fork pitch change mechanism includes a feed screw shaft, a nut member that engages with the feed screw shaft, and a slide member to which the nut member is attached, 5. The hand according to claim 1, wherein the base end of the fork is fixed to the slide member by the fork fixing mechanism.

6. If the direction perpendicular to the longitudinal direction and the vertical direction of the fork is defined as the orthogonal direction, A hand as described in any one of claims 1 to 5, characterized in that it comprises two forks arranged parallel to each other, and two straight second forks arranged between the two forks in the perpendicular direction and parallel to the forks.

7. 7. An industrial robot comprising: a hand according to claim 1; an arm to which the hand is rotatably connected at a tip end thereof; and a main body to which the arm is rotatably connected at a base end thereof.

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