Holding device for holding workpiece

Abstract

The present invention provides a holding device for holding a workpiece. The working tool of the holding device comprises: a first arm and a second arm moving in opposite directions; and a third arm engaging with the workpiece. The working tool comprises: a gear; and a gear moving cylinder moving the gear to a first position, a second position, and a third position between the first position and the second position. When the gear is arranged at the first position, the first arm and the second arm move. When the gear is arranged at the second position, the third arm moves. When the gear is arranged at the third position, the gear is separated from all arms.

Description

Technical Field

[0001] The present invention relates to a holding device for holding a workpiece. Background Art

[0002] It is known that when manufacturing a product, a workpiece is fixed by a holding device and various processes are performed. For example, it is known that parts are arranged on a workpiece fixed by a holding device and a coating is performed. Alternatively, it is known that when a workpiece is transported by a device including a robot, a holding device for holding the workpiece is installed on the robot as a working tool. When the holding device holds the workpiece, the robot changes its position and posture, thereby being able to arrange the workpiece at an arbitrary position or transport the workpiece (for example, Japanese Utility Model Publication No. 4-106184).

[0003] The holding device can clamp the workpiece by bringing the mutually opposing parts closer or farther away. Here, depending on the type of the workpiece, sometimes it is not possible to stably hold the workpiece by simply clamping the workpiece. In the prior art, a holding device is known, which, in addition to two parts for clamping the workpiece, also has a part that engages with the workpiece. It is known that in order to drive such a part for holding the workpiece, a mechanism with a rack and pinion or a connecting rod mechanism is used. As a driving source for the driving part, it is known to use a motor or a cylinder (for example, Japanese Utility Model Publication No. 47-34768 and Japanese Utility Model Publication No. 49-86574).

[0004] In addition, as a cylinder for driving various components, a cylinder in which a piston rod stops at three positions is known in addition to a cylinder in which a piston rod stops at two positions (for example, Japanese Patent Application Laid-Open No. 2001-38432). Summary of the invention

[0005] Depending on the device for processing the workpiece, multiple workpieces of different sizes may be processed. When multiple workpieces are fixed, the holding device can be replaced according to the size of the workpiece. In this case, there is a problem of needing multiple holding devices. In addition, time is required to replace the holding device, which increases the operation time. Or, when the working space is small, it is sometimes impossible to ensure a place to store multiple holding devices.

[0006] For example, a robot device having a robot and a working tool can transport workpieces of various sizes by replacing the working tool. The working tool can be automatically replaced by using an automatic tool changing device. However, there is a problem that a plurality of working tools must be prepared in advance. In addition, time is required to replace the working tool, and there is a problem of reduced working efficiency. Furthermore, when the working space is small, it is sometimes impossible to ensure a place to place the working tool.

[0007] Alternatively, a working tool that can hold workpieces of various sizes can be used. However, the motor, cylinder, and structural components of the working tool become larger, so there is a problem of the working tool becoming heavier. For robots, there is a limit on the weight of the working tools that can be installed. In a small robot, it is impossible to operate a large working tool, and multiple working tools need to be used. Especially in a working tool that engages with the workpiece in more than three places, the number of motors used to drive the parts that hold the workpiece increases. As a result, even if the workpiece is light, the weight of the working tool increases, and there is a problem that a small robot cannot operate it.

[0008] One mode of the present disclosure is a holding device for holding a workpiece. The holding device includes: a first arm and a second arm that clamp the workpiece by moving in opposite directions. The holding device includes a third arm that moves in a direction intersecting the direction in which the first arm and the second arm move and engages with the workpiece. The holding device includes: a rotating member that contacts the first arm, the second arm, and the third arm and moves each arm; and a rotating machine that rotates the rotating member. The holding device includes a rotating member moving cylinder for moving the rotating member to a first position, a second position, and a third position between the first position and the second position. The first arm and the second arm are configured so that when the rotating member is configured in the first position, the first arm contacts one side of the rotating member and the second arm contacts the other side of the rotating member. The third arm is configured so that when the rotating member is configured in the second position, it contacts the rotating member. The first arm, the second arm, and the third arm are configured so that when the rotating member is configured in the third position, they are separated from the rotating member. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a perspective view of the robot device according to the embodiment.

[0010] Figure 2 This is a perspective view of a working tool as a first gripping device according to the embodiment as viewed from the front.

[0011] Figure 3 This is a perspective view of a working tool as a first gripping device as viewed from the rear side.

[0012] Figure 4 It is a first schematic cross-sectional view of the gear moving cylinder according to the embodiment.

[0013] Figure 5 It is a second schematic cross-sectional view of the gear moving cylinder.

[0014] Figure 6 It is a third schematic cross-sectional view of the gear moving cylinder.

[0015] Figure 7 It is a block diagram of a robot device according to an embodiment.

[0016] Figure 8 It is an enlarged perspective view of the working tool when the gear is arranged in the first position.

[0017] Fig. 9 It is a perspective view for explaining the positional relationship among the moving member, the gear, and the plurality of arms when the gear is arranged at the first position.

[0018] Fig.10 It is an enlarged perspective view of the working tool when the gear is arranged in the second position.

[0019] Fig.11 It is a perspective view for explaining the positional relationship among the moving member, the gear, and the plurality of arms when the gear is arranged at the second position.

[0020] Fig.12 It is an enlarged perspective view of the working tool when the gear is arranged in the third position.

[0021] Fig.13 It is a perspective view for explaining the positional relationship among the moving member, the gear, and the plurality of arms when the gear is arranged at the third position.

[0022] Fig.14 This is a perspective view of a rack and a robot device when the robot device is taking a workpiece out of the rack.

[0023] Fig.15 This is a perspective view of a robot device and a workpiece for explaining a first step in which the robot device takes out a workpiece from a rack.

[0024] Fig.16 This is a perspective view of the robot device and the workpiece for explaining the second step in which the robot device takes out the workpiece from the rack.

[0025] Fig.17 It is an enlarged perspective view of a working tool as a second gripping device according to the embodiment.

[0026] Fig.18 It is a perspective view of a third holding device according to the embodiment.

[0027] Fig.19 It is a cross-sectional view of a pressing plate of a third gripping device according to the embodiment.

[0028] Fig. 20 This is a perspective view of the third holding device when holding a large workpiece.

[0029] Fig.21 It is a perspective view showing another state of the third holding device.

[0030] Fig. 22 This is a perspective view of the third holding device when holding a small workpiece. DETAILED DESCRIPTION

[0031] Reference Figures 1 to 22 The gripping device of the embodiment is described below. The gripping device of the embodiment is formed to be able to grip workpieces of various sizes.

[0032] Figure 1 1 is a schematic diagram of a robot device according to the present embodiment. The robot device 5 includes a working tool 2 and a robot 1 for moving the working tool 2. The first gripping device of the present embodiment is the working tool 2 of the robot 1. The working tool 2 is connected to the robot 1. The robot device 5 transports the workpiece by causing the robot 1 to change its position and posture while the working tool 2 grips the workpiece.

[0033] The robot 1 of the present embodiment is a multi-joint robot including a plurality of joints. The robot 1 includes a base portion 14 and a swivel base 13 supported by the base portion 14. The base portion 14 is fixed to a setting surface. The swivel base 13 is formed to rotate relative to the base portion 14. The robot 1 includes an upper arm 11 and a lower arm 12. The lower arm 12 is rotatably supported on the swivel base 13 via a joint portion. The upper arm 11 is rotatably supported on the lower arm 12 via a joint portion. In addition, the upper arm 11 rotates around a rotation axis parallel to the direction in which the upper arm 11 extends.

[0034] The robot 1 includes a toggle lever 15 connected to the end of the upper arm 11. The toggle lever 15 is rotatably supported on the upper arm 11 via a joint. The toggle lever 15 includes a rotatable flange 16. The working tool 2 is fixed to the flange 16. The robot 1 of this embodiment has six drive axes, but is not limited to this. Any robot that can change the position and direction of the working tool 2 can be used.

[0035] The robot device 5 of this embodiment has an automatic tool changer (ATC) that can automatically change the working tool. The automatic tool changer has a robot side plate 51 mounted on the flange 16 of the robot 1 and a tool side plate 52 mounted on the working tool 2. The tool side plate 52 is formed to be connected to or released from the robot side plate 51. In addition, the working tool 2 can also be fixed to the flange 16 without passing through the automatic tool changer.

[0036] Figure 2 The following is a perspective view of the working tool according to the present embodiment when viewed from the front. Figure 3The figure shows a stereoscopic view of the working tool of the present embodiment as viewed from the rear side. In the present embodiment, as indicated by arrow 104, the side where the workpiece is arranged is referred to as the front side. The working tool 2 has a frame 21 including a top plate 23 and a side plate 22. A tool side plate 52 of an automatic tool changing device is fixed to the top plate 23. The side plate 22 supports the top plate 23 and supports the first arm 65 and the second arm 66. The frame 21 has two support plates 24 for supporting the third arm 67. The support plates 24 are arranged on the front and rear sides of the side plates 22.

[0037] The working tool 2 includes a first arm 65 and a second arm 66 that move in opposite directions. A workpiece is clamped by the first arm 65 and the second arm 66. The first arm 65 includes a rod-shaped member 25 and a pressing plate 27 fixed to the end of the rod-shaped member 25. The second arm 66 includes a rod-shaped member 26 and a pressing plate 27 fixed to the end of the rod-shaped member 26. The rod-shaped member 25 and the rod-shaped member 26 are inserted through the holes 22a and 22b formed in the side plate 22. The rod-shaped member 25 and the rod-shaped member 26 are supported by the holes 22a and 22b.

[0038] Each pressing plate 27 has a groove 27a extending linearly. The groove 27a is formed to extend from the front end to the rear end of the pressing plate 27. The workpiece of this embodiment is a plate-shaped member. The groove 27a is formed to allow the end of the workpiece to be inserted.

[0039] The working tool 2 has a third arm 67 that moves in a direction intersecting the directions in which the first arm 65 and the second arm 66 move. In the present embodiment, as indicated by an arrow 92, the third arm 67 moves in a direction perpendicular to the directions in which the first arm 65 and the second arm 66 move. The third arm 67 includes a rod-shaped member 28 and a clamping device 31 fixed to an end of the rod-shaped member 28.

[0040] The working tool 2 includes a rotating member that contacts the first arm 65, the second arm 66, and the third arm 67 and moves each arm 65, 66, 67. In the present embodiment, a gear 38 is provided as a rotating member. The gear 38 of the present embodiment is a flat gear. As for the working tool 2, a gear drive motor 36 is provided as a rotating machine that rotates the gear 38. As a rotating machine that rotates the rotating member, it is not limited to an electric motor, and any rotating machine can be used. For example, it can also be a rotating machine driven by hydraulic pressure.

[0041] The gear drive motor 36 has a shaft 37 for outputting a rotational force. A notch 37a formed in a planar shape is formed on the shaft 37. The gear 38 has a hole corresponding to the cross-sectional shape of the shaft 37. The shaft 37 is inserted through the hole. By forming the notch 37a on the shaft 37, it is possible to prevent the gear 38 from idling relative to the shaft 37.

[0042] The first arm 65 and the second arm 66 move in the direction indicated by the arrow 91. That is, the rod-shaped member 25 and the rod-shaped member 26 move in the axial direction. The rod-shaped member 25 and the rod-shaped member 26 are arranged to face each other. A plurality of teeth engaging with the gear 38 are formed on the surface of each rod-shaped member 25, 26 facing the gear 38. In the present embodiment, the first arm 65 and the second arm 66 move by a rack and pinion mechanism.

[0043] The third arm 67 moves in the axial direction of the rod-shaped member 28. The rod-shaped member 28 is inserted through the hole 24a formed in the support plate 24. The rod-shaped member 28 is supported by the hole 24a of the front support plate 24 and the hole 24a of the rear support plate 24. A plurality of teeth are formed on the surface of the rod-shaped member 28 facing the gear 38 so as to engage with the teeth of the gear 38. In the present embodiment, the third arm 67 moves by the rack and pinion mechanism.

[0044] The clamping device 31 of the third arm 67 is formed to be able to clamp a workpiece. The clamping device 31 has a frame 32. The clamping device 31 has claws 34a and 34b for clamping the workpiece. The clamping device 31 has a claw driving cylinder 33 for moving the claw 34a in the direction indicated by the arrow 93. The claw driving cylinder 33 is supported by the frame 32. The claw 34a is driven by the claw driving cylinder 33, and the claw 34a moves in the direction toward the claw 34b, so that the workpiece can be clamped by the claw 34a and the claw 34b.

[0045] The gear 38 of this embodiment is formed to slide relative to the shaft 37. That is, as shown by arrow 103, the gear 38 moves along the axial direction of the shaft 37. In this embodiment, the gear 38 moves to a first position, a second position, and a third position. The gear 38 engages with the first arm 65 and the second arm 66 at the first position. The gear 38 engages with the third arm 67 at the second position. The gear 38 is separated from all the arms 65, 66, and 67 at the third position.

[0046] The working tool 2 has a gear moving cylinder 39 as a rotating member moving cylinder for moving the gear 38 to the first position, the second position, and the third position. The working tool 2 has a moving member 61 connected to the gear moving cylinder 39. The moving member 61 is driven by the gear moving cylinder 39, and as shown by the arrow 103, it moves along the axial direction of the shaft 37. The moving member 61 presses the gear 38, thereby moving the gear 38 to the first position, the second position, and the third position.

[0047] Figure 4 A first schematic cross-sectional view of the gear moving cylinder of this embodiment is shown. The gear moving cylinder 39 of this embodiment is a three-position cylinder. The gear moving cylinder 39 is formed so as to stop the first sliding member 71 fixed to the moving member 61 at three positions.

[0048] The gear moving cylinder 39 includes a housing 70 and a first sliding member 71 disposed in a space inside the housing 70. The first sliding member 71 includes a first piston 71a, a first piston rod 71b, and a flange 71c disposed at the front end of the first piston rod 71b. A space is formed inside the first sliding member 71.

[0049] The gear moving cylinder 39 has a second sliding member 72 that moves coaxially with the first sliding member 71. The second sliding member 72 has a second piston 72a and a second piston rod 72b. An air supply pipe 77 is inserted into the interior of the second sliding member 72. A sealing member 79 is arranged at a portion where the first sliding member 71 and the housing 70 are in contact. In addition, a sealing member 79 is arranged at a portion where the second sliding member 72 and the housing 70 are in contact, and at a portion where the second sliding member 72 and the air supply pipe 77 are in contact.

[0050] An air chamber 74 is formed between the inner surface of the housing 70 and the outer surface of the first sliding member 71. An air chamber 75 is formed inside the first sliding member 71. Furthermore, an air chamber 76 is formed by a space surrounded by the second piston 72a of the second sliding member 72 and the inner surface of the housing 70.

[0051] Figure 4 The gear moving cylinder 39 is shown when the gear 38 is arranged in the first position. As shown by arrow 94, pressurized air is supplied to the air chamber 74. Pressurized air is not supplied to the air chambers 75 and 76. The first slide member 71 is pulled into the interior of the housing 70.

[0052] Figure 5 A second schematic cross-sectional view of the gear moving cylinder according to the present embodiment is shown. Figure 6 A third schematic cross-sectional view shows the gear moving cylinder according to the present embodiment. Figure 5 The gear moving cylinder 39 is shown when the gear 38 is arranged in the third position. Figure 6 The gear moving cylinder 39 is shown when the gear 38 is arranged in the second position. Figure 5 , the first sliding member 71 is arranged at the middle position. As shown by arrows 94 and 95, pressurized air is supplied to the air chamber 74 and the air chamber 75. The pressure of the air in the air chamber 75 causes the first sliding member 71 to be arranged at a position greater than Figure 4 The location shown is the location of the pop-up.

[0053] Reference Figure 6, the first sliding member 71 is arranged at the position where it is most ejected. As shown by arrows 94, 95, and 96, pressurized air is supplied to the air chambers 74, 75, and 76. The second sliding member 72 moves toward the outside due to the pressure of the air in the air chamber 76. In this way, the gear moving cylinder 39 of this embodiment is formed so that the first sliding member 71 can be stopped at three positions and maintained at the positions.

[0054] Figure 7 A block diagram showing a robot device according to this embodiment. Figure 1 , Figure 2 as well as Figure 7 The robot 1 includes a robot driving device that changes the position and posture of the robot 1. The robot driving device includes a plurality of robot driving motors 17 that drive structural components such as arms and elbows. A robot driving motor 17 is configured for each of the plurality of structural components. The orientation of each structural component changes by driving the robot driving motor 17.

[0055] The robot device 5 includes a robot control device 4 for controlling the robot 1 and the working tool 2. The robot control device 4 includes a processing unit (computer) having a CPU (Central Processing Unit) as a processor. The processing unit has a RAM (Random Access Memory) and a ROM (Read Only Memory) connected to the CPU via a bus. In order to control the robot 1 and the working tool 2, an action program 41 is input to the robot control device 4. Alternatively, the robot control device 4 generates the action program 41 according to the teaching operation of the operator. The robot control device 4 includes a storage unit 42 for storing information related to the control of the robot device 5. The storage unit 42 can be composed of a storage medium that can store information, such as a volatile memory, a non-volatile memory, or a hard disk. The action program 41 is stored in the storage unit 42. The robot device 5 of this embodiment transports the workpiece based on the action program 41.

[0056] The robot control device 4 includes a motion control unit 43 that sends motion instructions. The CPU as a processor functions as the motion control unit 43 by obtaining the motion program 41 and implementing the control specified by the motion program 41. The motion control unit 43 sends the motion instruction for driving the robot 1 to the robot driving unit 45 based on the motion program 41. The robot driving unit 45 includes a circuit that drives the robot driving motor 17. The robot driving unit 45 supplies power to the robot driving motor 17 based on the motion instruction.

[0057] The robot 1 includes a state detector for detecting the position and posture of the robot 1. The state detector of this embodiment includes a position detector 18 attached to a robot drive motor 17. The robot control device 4 detects the position and posture of the robot 1 based on the output of the position detector 18.

[0058] In addition, the motion control unit 43 sends the motion command for driving the working tool 2 to the working tool driving unit 44 based on the motion program 41. The working tool driving unit 44 includes an electric circuit and a pneumatic circuit for driving a driving device of the working tool 2. The working tool driving unit 44 supplies power to the gear driving motor 36 based on the motion command. In addition, the working tool driving unit 44 supplies pressurized air to the claw driving cylinder 33 and the gear moving cylinder 39 based on the motion command.

[0059] Next, the functions of the working tool and the robot device according to the present embodiment will be described in detail. Figure 8 An enlarged perspective view of the working tool showing a state in which the gear is arranged in the first position. Fig. 9 A perspective view showing a moving member, a gear, and a plurality of arms when the gear is arranged in a first position. Fig. 9 In the figure, for the purpose of illustration, the side plate 22 and the support plate 24 in the frame 21 are omitted. Figure 8 and Fig. 9 The moving member 61 of the present embodiment has an engaging portion 61a that engages with the gear 38. The engaging portion 61a has a U-shaped cross section. The engaging portion 61a of the present embodiment has a shape that sandwiches the gear 38.

[0060] The moving member 61 has a first pressing portion 61b that moves together with the engaging portion 61a. The first pressing portion 61b extends toward the rod-shaped member 28 of the third arm 67. The first pressing portion 61b is connected to the end of the engaging portion 61a. The first pressing portion 61b has a front end portion with an L-shaped cross-section. As described later, the first pressing portion 61b presses and brakes the rod-shaped member 28 of the third arm 67.

[0061] The moving member 61 has a second pressing portion 61c that moves together with the engaging portion 61a. The second pressing portion 61c is connected to the end of the engaging portion 61a. The second pressing portion 61c is formed in a plate shape. As described later, the second pressing portion 61c presses and brakes the rod-shaped member 25 of the first arm 65 and the rod-shaped member 26 of the second arm 66. The second pressing portion 61c is connected to the flange 71c of the gear moving cylinder 39. In the present embodiment, the engaging portion 61a, the first pressing portion 61b, and the second pressing portion 61c are formed integrally.

[0062] exist Figure 8 and Fig. 9 In the example shown, the first slide member 71 of the gear moving cylinder 39 is arranged in the position where it is pulled in the most (see Figure 4 ). The moving member 61 and the gear 38 move in the direction indicated by the arrow 97. The shaft 37 of the gear drive motor 36 is inserted into the hole 61d of the engagement portion 61a.

[0063] The gear 38 is engaged with the first arm 65 and the second arm 66 when arranged in the first position. The rod-shaped member 25 of the first arm 65 contacts one side of the gear 38. In addition, the rod-shaped member 26 of the second arm 66 contacts the other side of the gear 38. The gear 38 meshes with the teeth formed on the rod-shaped members 25 and 26. The first arm 65 and the second arm 66 are moved in opposite directions by the drive of the gear drive motor 36. The pressing plate 27 of the first arm 65 and the pressing plate 27 of the second arm 66 are moved in a direction approaching each other by the rotation of the shaft 37 in one direction. In addition, the pressing plate 27 of the first arm 65 and the pressing plate 27 of the second arm 66 are moved in a direction away from each other by the rotation of the shaft 37 in the other direction. In this way, the workpiece can be clamped or released by the two pressing plates 27 facing each other by the drive of the gear drive motor 36.

[0064] In addition, when the gear 38 is arranged in the first position, the first pressing portion 61b presses the surface of the rod-shaped member 28 of the third arm 67. When the gear 38 is arranged in the first position, the moving member 61 moves in the direction indicated by the arrow 97. At this time, the first pressing portion 61b presses the lower surface of the rod-shaped member 28. By adopting this structure, the movement of the third arm 67 can be prevented. The working tool 2 of this embodiment is formed so that when the first arm 65 and the second arm 66 are moved, the third arm 67 is braked.

[0065] Fig.10 An enlarged perspective view of the working tool showing a case where the gear is arranged in the second position. Fig.11 A perspective view showing a gear, a moving member, and a plurality of arms when the gear is arranged in the second position. Fig.10 and Fig.11 , the gear moving cylinder 39 is driven, so that the moving member 61 moves as shown by the arrow 98. The first sliding member 71 of the gear moving cylinder 39 is arranged at the position of maximum ejection (refer to Figure 6 ) The shaft 37 of the gear drive motor 36 is inserted through the hole 61e formed in the second pressing portion 61c.

[0066] The gear 38 is pressed by the engagement portion 61a of the moving member 61 and moves to the second position. The gear 38 is released from engagement with the first arm 65 and the second arm 66. The gear 38 is engaged with the rod-shaped member 28 of the third arm 67. The teeth of the gear 38 mesh with the teeth of the rod-shaped member 28.

[0067] When the gear 38 is arranged in the second position, the third arm 67 is driven by the gear drive motor 36 to move in the direction indicated by the arrow 92. On the other hand, when the moving member 61 moves in the direction indicated by the arrow 98, the second pressing portion 61c presses the upper surface of the rod-shaped member 25 of the first arm 65 and the upper surface of the rod-shaped member 26 of the second arm 66. Therefore, the first arm 65 and the second arm 66 are braked. In this way, the working tool 2 is formed so that the first arm 65 and the second arm 66 are braked when the third arm 67 is moved.

[0068] Fig.12 An enlarged perspective view of the working tool showing a case where the gear is arranged in the third position. Fig.13 A perspective view showing the moving member, the gear, and the plurality of arms when the gear is arranged in the third position. The first sliding member 71 of the gear moving cylinder 39 is arranged in the middle position (refer to Figure 5 ). Reference Fig.12 and Fig.13 , driven by the gear moving cylinder 39, the gear 38 is arranged at the third position. The third position is an intermediate position between the first position and the second position.

[0069] When the gear 38 is arranged at the third position, the gear 38 is disengaged from all the rod-shaped members 25, 26, 28. That is, the gear 38 is separated from all the arms 65, 66, 67. In addition, the first pressing portion 61b is separated from the rod-shaped member 28, and the second pressing portion 61c is separated from the rod-shaped members 25, 26. Therefore, each arm 65, 66, 67 is in a state of being able to move freely.

[0070] Next, the operation of the robot device according to this embodiment will be described. Fig.14 A perspective view showing a rack storing workpieces and a robot device according to the present embodiment. The robot device 5 according to the present embodiment performs an operation of taking out a workpiece 89 from a rack 81 storing the workpieces 89 and moving the workpiece 89 to another location.

[0071] The workpiece 89 of the present embodiment is a substrate formed in a plate shape. The rack 81 has side plates 82 facing each other. A groove 82a extending in a horizontal direction is formed on the inner surface of the side plate 82. The groove 82a is formed to reach the end of the side plate 82. The groove 82a of the side plate 82 on one side and the groove 82a of the side plate 82 on the other side are formed at positions facing each other. The workpiece 89 is supported by inserting the ends of both sides of the workpiece 89 into the groove 82a. The working tool 2 of the present embodiment implements the operation of clamping and pulling out the workpiece 89 supported by the groove 82a.

[0072] Fig.15 A perspective view of a robot device illustrating a first step of an operation. Figure 7 , Fig.14 ,as well as Fig.15, the motion control unit 43 drives the gear moving cylinder 39 to place the gear 38 in the first position. The gear 38 engages with the first arm 65 and the second arm 66. The third arm 67 is braked. The motion control unit 43 drives the gear driving motor 36 to move the first arm 65 and the second arm 66 as shown by the arrow 99. The motion control unit 43 adjusts the interval between the pressing plate 27 of the first arm 65 and the pressing plate 27 of the second arm 66 to correspond to the length of the workpiece 89 in the longitudinal direction.

[0073] The motion control unit 43 changes the position and posture of the robot 1 so that the groove 27a formed on the pressing plate 27 and the groove 82a formed on the side plate 82 of the frame 81 become the same linear shape. Next, the motion control unit 43 drives the gear moving cylinder 39 to move the gear 38 to the second position. The gear 38 is engaged with the third arm 67. The first arm 65 and the second arm 66 are braked. The motion control unit 43 drives the gear drive motor 36 to move the third arm 67 toward the workpiece 89. The motion control unit 43 moves the third arm 67 to a position where the workpiece 89 can be clamped by the clamping device 31.

[0074] Next, the motion control unit 43 drives the claw drive cylinder 33 to move the claw 34a toward the claw 34b as indicated by the arrow 101. The workpiece 89 is clamped by the claw 34a and the claw 34b. Next, the motion control unit 43 drives the gear drive motor 36 to pull in the third arm 67 as indicated by the arrow 100. The workpiece 89 moves from the groove 82a of the rack 81 to the groove 27a of the pressing plate 27 of the arms 65 and 66.

[0075] Fig.16 A perspective view of a robot device is shown to explain a second step of the operation. Fig.16 The state indicating that the gripping of the workpiece is completed. The motion control unit 43 moves the third arm 67 to a predetermined position. Then, the motion control unit 43 stops the rotation of the shaft 37 of the gear drive motor 36. The motion control unit 43 continues the excitation of the gear drive motor 36 to maintain the position of the third arm 67. In this way, the working tool 2 can grip the workpiece 89.

[0076] Next, the motion control unit 43 transports the workpiece 89 to a desired position by changing the position and posture of the robot 1. Then, when releasing the workpiece 89, for example, the motion control unit 43 drives the gear drive motor 36 to move the third arm 67 in the ejection direction. The workpiece 89 is released from the first arm 65 and the second arm 66. Thereafter, the motion control unit 43 can release the workpiece 89 by moving the claw 34a of the clamping device 31.

[0077] In addition, in the above embodiment, after adjusting the interval between the pressing plate 27 of the first arm 65 and the pressing plate 27 of the second arm 66, the workpiece 89 is pulled in by the third arm 67, but the present invention is not limited to this method. Each arm can move in any order. For example, after slightly pulling the workpiece out of the rack by the third arm, the workpiece can be clamped by the first arm and the second arm.

[0078] In addition, the working tool of this embodiment is formed to hold a plate-shaped workpiece, but is not limited to this mode. The working tool can be formed to hold a workpiece of any shape. For example, the pressing plate of each arm can be formed in a shape corresponding to the shape of the workpiece. Furthermore, the claw portion of the clamping device can be formed in a shape corresponding to the shape of the clamped portion of the workpiece.

[0079] In the working tool 2 of the present embodiment, the gear 38 is formed to be movable in order to engage with a plurality of arms 65, 66, and 67. The arms 65 and 66 that clamp the workpiece 89 from both sides and the arm 67 that engages with the workpiece 89 from other directions can be moved by a gear drive motor 36. In the working tool 2 of the present embodiment, the number of rotating machines for driving the arms can be reduced. There is no need to configure a first motor that drives the arms that clamp the workpiece on both sides and a second motor that drives the arms that engage with the workpiece from other directions, and three arms can be driven by one motor. Therefore, the working tool can be made lightweight. As a result, the working tool 2 can be operated by a small robot.

[0080] Furthermore, in the working tool 2 of this embodiment, the arms 65 and 66 that clamp the workpiece 89 and the arm 67 that holds the workpiece 89 can be moved independently. Therefore, the working tool 2 can hold workpieces of various sizes. In this way, the working tool of this embodiment is lightweight and can hold workpieces of various sizes.

[0081] In addition, in the present embodiment, the rotating member is configured in a third position between the first position and the second position. In the third position, the rotating member is separated from all arms. When the contacting arms are switched, the rotating member comes into engagement with one arm and then engages with the other arm. When the rotating member changes the engaged arm, the rotating member passes through the position separated from all arms, thereby enabling smooth switching of the arms.

[0082] Reference Figure 7The robot control device 4 of this embodiment functions as a control device for controlling the gear drive motor 36. The working tool 2 is provided with a position detector 35 for detecting the rotation angle of the gear drive motor 36. The position detector 35 can be composed of an encoder or the like. The storage unit 42 of the robot control device 4 can store information related to the control of the gear drive motor 36. The robot control device 4 can detect the positions of the arms 65, 66, and 67 of the working tool 2 based on the output of the position detector 35.

[0083] The position detector 35 of this embodiment detects the rotation angle of the gear drive motor 36, but is not limited to this method. The position detector can be any detector for detecting the position of each arm. For example, the position of each arm of the working tool can be detected by configuring a linear scale.

[0084] The robot control device 4 has a signal processing unit 46 for controlling the gear drive motor 36. The CPU as a processor functions as the signal processing unit 46 by obtaining the action program 41 and implementing the control specified by the action program 41. The gear 38 passes through the third position when moving from the first position to the second position. The position detector 35 detects the rotation angle of the gear drive motor 36 when the gear 38 moves from the first position to the third position. The signal processing unit 46 obtains the rotation angle from the position detector 35 and stores it in the storage unit 42. Thereafter, the gear moving cylinder 39 moves the gear 38 from the first position to the second position.

[0085] Then, when the gear 38 is moved from the second position to the first position, the gear moving cylinder 39 stops the gear 38 at the third position. The signal processing unit 46 obtains the rotation angle of the gear drive motor 36 when the gear 38 is moved from the first position to the second position from the storage unit 42. The signal processing unit 46 sends the rotation angle to the motion control unit 43. The motion control unit 43 controls the gear drive motor 36 so that it becomes the rotation angle received from the signal processing unit 46. Then, the gear moving cylinder 39 moves the gear 38 from the third position to the first position.

[0086] Similar to the above control, when the gear 38 moves from the second position to the first position, the position detector 35 detects the rotation angle of the gear drive motor 36. The storage unit 42 stores the rotation angle of the gear drive motor 36. Then, the gear moving cylinder 39 moves the gear 38 from the second position to the first position.

[0087] Next, when the gear 38 is moved from the first position to the second position, the gear moving cylinder 39 stops the gear 38 at the third position. The signal processing unit 46 obtains the rotation angle of the gear driving motor 36 when the gear 38 is moved from the second position to the first position from the storage unit 42. The operation control unit 43 controls the rotation angle of the gear driving motor 36 so as to become the rotation angle received from the signal processing unit 46. Next, the gear moving cylinder 39 moves the gear 38 from the third position to the second position.

[0088] In this way, the signal processing unit 46 detects the rotation angle of the gear drive motor 36 when the gear 38 is separated from the arm. Then, when the gear 38 is engaged with the arm again, control is performed to return the rotation angle of the gear drive motor 36 to the rotation angle when the gear 38 is separated from the arm. By implementing this control, the gear 38 is engaged at the original position of the rod-shaped member of the arm. As a result, the position of each arm 65, 66, 67 can be detected using the rotation angle of the gear drive motor 36. In addition, it is possible to avoid the gear 38 being unable to move due to the teeth of the gear 38 and the teeth of the rod-shaped members 25, 26, 28 not being engaged. The gear 38 can be smoothly moved from the third position to the first position, or from the third position to the second position.

[0089] In the above-mentioned embodiment, the rotating parts in contact with each arm are composed of gears, but are not limited to this mode. For example, each arm can also be moved by adopting a ball screw mechanism. Alternatively, a circular plate can be used as the rotating part. Moreover, anti-skid parts such as rubber can be pasted on the circumferential surface of the circular plate. Anti-skid parts such as rubber can also be configured on the rod-shaped parts in contact with the rotating parts. As the rubber of the anti-skid part, for example, polyurethane rubber can be used. According to this structure, the rotating part contacts the rod-shaped part of the arm and rotates, thereby also being able to move the arm.

[0090] In the above-mentioned embodiment, the moving member 61 includes: the first pressing portion 61b pressing the third arm 67 when the gear 38 is arranged in the first position; and the second pressing portion 61c pressing the first arm 65 and the second arm 66 when the gear 38 is arranged in the second position. By adopting this structure, the arm that is not moved by the gear drive motor 36 can be braked with a simple structure.

[0091] Fig.17 An enlarged stereoscopic view of a working tool as a second gripping device according to the present embodiment is shown. In the working tool 6 as the second gripping device, the moving part does not have a function of braking the arms 65, 66, and 67. A braking device for braking the arms is provided on the working tool 6. The moving part 61 of the working tool 6 has an engaging portion 61a, but does not have a first pressing portion and a second pressing portion. The flange 71c disposed at the front end of the first sliding part 71 of the gear moving cylinder 39 is fixed to the engaging portion 61a.

[0092] A brake device for braking the first arm 65 and the second arm 66 is disposed on the side plate 22 of the frame 21. The brake device includes a cylinder 83 fixed to the side plate 22 and a brake member 84 of a piston rod fixed to the cylinder 83. The brake member 84 is driven by the cylinder 83 to move toward the rod-shaped members 25 and 26 as indicated by the arrow 105. The brake member 84 presses the rod-shaped members 25 and 26, thereby being able to brake the first arm 65 and the second arm 66.

[0093] In addition, a brake device for braking the third arm 67 is arranged on the other side plate 22 of the frame 21. The brake device includes a cylinder 85 fixed to the side plate 22 and a brake member 86 fixed to a piston rod of the cylinder 85. The brake member 86 is driven by the cylinder 85 to move toward the rod-shaped member 28 as indicated by an arrow 106. The brake member 86 presses the rod-shaped member 28, thereby being able to brake the third arm 67.

[0094] In this way, a device for braking each arm 65, 66, 67 at an arbitrary time may be provided. By adopting this structure, each arm can be braked at an arbitrary time. For example, when the gear 38 is moved, by braking all the arms 65, 66, 67, the gear 38 can be moved stably.

[0095] Fig.18 A three-dimensional diagram showing the third holding device of the present embodiment. The third holding device 7 can be fixed to any device. For example, the third holding device 7 can be fixed on a workbench or on a conveyor. Alternatively, the third holding device 7 can be fixed to a workbench of a machine tool, etc. In addition, the third holding device 7 can be configured in a device that needs to hold a workpiece. For example, the third holding device 7 can be configured in a device that uses a laser to perform engraving, a coating device that forms a film on the surface of a workpiece, or a device that configures a component on the surface of a substrate.

[0096] The holding device 7 includes a support member 88 for supporting the frame 21. The support member 88 has a box shape. The holding device 7 is not provided with a tool side plate for connecting to the robot. Regarding the holding device 7, the shape of the pressing plate 29 of each of the first arm 65 and the second arm 66 is different from the shape of the pressing plate 27 of the working tools 2 and 6. In addition, in the third arm 67, a pressing plate 30 is arranged at the front end of the rod-shaped member 28. Notches 29a and 30a are formed in the upper part of each pressing plate 29 and 30 in a manner that a workpiece can be placed. In addition, a notch 24b is formed in the upper part of the support plate 24 arranged on the front side of the frame 21 in a manner that a workpiece can be placed. In addition, a through portion 29c is formed in each pressing plate 29 in a manner that the rod-shaped members 25 and 26 of the arms 65 and 66 are inserted when the arms 65 and 66 move.

[0097] Fig.19 A cross-sectional view showing a pressing plate of a third holding device. The notch 29a of the pressing plate 29 is formed to have an L-shaped cross-sectional shape. An inclined portion 29b having an inclined inner surface is formed at the front end of the pressing plate 29. When a workpiece is placed, even if the position of the workpiece is slightly offset, the inclined portion 29b can be used to move the workpiece toward the inside of the notch 29a. The front ends of the pressing plate 30 and the support plate 24 have the same shape as the front end of the pressing plate 29.

[0098] Reference Fig.18 The gripping device 7 is provided with a control device 87. The control device 87 is composed of a calculation processing device (computer) having a CPU and RAM as a processor. The gear drive motor 36 and the gear moving cylinder 39 are controlled by the control device 87. In addition, similar to the robot control device 4, the control device 87 has a storage unit 42, an action control unit 43, a gripping device drive unit corresponding to the working tool drive unit 44, and a signal processing unit 46. Furthermore, the gripping device 7 has a position detector 35 (refer to Figure 7 ).

[0099] Fig. 20 A perspective view showing the third gripping device when gripping a large workpiece. The workpiece 90a is placed on the notches 29a, 30a of the pressing plates 29, 30 and the notch 24b of the support plate 24. The workpiece 90a can be clamped in the length direction by the notch 29a of the pressing plate 29 of the first arm 65 and the notch 29a of the pressing plate 29 of the second arm 66. In addition, the workpiece 90a can be clamped in the width direction by the notch 30a of the pressing plate 30 of the third arm 67 and the notch 24b of the support plate 24. In this way, the workpiece 90a can be gripped by clamping the workpiece 90a from different directions.

[0100] When holding the workpiece 90a, the control device 87 moves the first arm 65 and the second arm 66 so that the interval between the notch portions 29a of the pressing plates 29 of the arms 65 and 66 corresponds to the length of the longitudinal direction of the workpiece 90a. In addition, the control device 87 moves the third arm 67 so that the interval between the notch portion 30a of the pressing plate 30 and the notch portion 24b of the support plate 24 corresponds to the length of the width direction of the workpiece 90a. Then, the workpiece 90a can be placed on the notch portions 29a, 30a, and 24b by a robot or an operator. The workpiece 90a is held in the area surrounded by the notch portions 29a, 30a, and 24b. In the holding device 7, the workpiece can be held by clamping the workpiece from two different directions.

[0101] Fig.21 Another perspective view showing the third gripping device according to this embodiment. Fig. 22A perspective view showing a third gripping device for gripping a small workpiece. Fig.21 and Fig. 22 In the example shown, the interval between the pressing plate 29 of the first arm 65 and the pressing plate 29 of the second arm 66 is reduced. In addition, the interval between the pressing plate 30 of the third arm 67 and the support plate 24 is reduced. The rod-shaped member 26 of the second arm 66 penetrates the through-portion 29c formed in the pressing plate 29 of the first arm 65. Similarly, the rod-shaped member 25 of the first arm 65 penetrates the through-portion 29c formed in the pressing plate 29 of the second arm 66. The gripping device 7 can grip a small workpiece 90b by adjusting the positions of the respective arms 65, 66, and 67.

[0102] In the holding device 7, it is also possible to hold a plurality of workpieces 90a and 90b of different sizes. In addition, the holding device 7 can use a small number of motors to move a plurality of arms 65, 66, and 67 to hold the workpieces 90a and 90b. Therefore, the holding device 7 can reduce the weight. Furthermore, the holding device 7 can fix the workpiece at a predetermined position according to the size of the workpiece. For example, when the shapes of the workpieces are the same, the workpieces can always be fixed at the same position.

[0103] The other structures, functions, and effects of the third holding device are the same as those of the first holding device and the second holding device described above, and therefore, they will not be described again here.

[0104] According to the aspect of the present disclosure, it is possible to provide a lightweight gripping device capable of gripping a plurality of workpieces of different sizes.

[0105] The above-mentioned embodiments can be combined appropriately. In the above-mentioned figures, the same or equivalent parts are marked with the same symbols. In addition, the above-mentioned embodiments are examples and do not limit the invention. In addition, the embodiments include changes to the embodiments shown in the claims.

Claims

1. A holding device, which is a holding device for holding a workpiece, characterized in that: have: a first arm and a second arm that clamp a workpiece by moving in opposite directions to each other; a third arm that moves in a direction intersecting the directions in which the first arm and the second arm move and engages with the workpiece; a rotating member that contacts the first arm, the second arm, and the third arm and moves each arm; A rotating machine having a shaft and rotating the rotating member, wherein the rotating member is engaged with the shaft in a relatively sliding manner along the shaft; a moving member engaged with the shaft in a manner of relative movement along the shaft and having a shape that sandwiches the rotating member; as well as a rotating member moving cylinder for moving the moving member so that the rotating member sandwiched by the moving member slides relative to the shaft at a first position, a second position, and a third position between the first position and the second position, The first arm and the second arm are arranged so that when the rotating member is arranged in the first position, the first arm contacts one side of the rotating member and the second arm contacts the other side of the rotating member. The third arm is configured to contact the rotating member when the rotating member is configured in the second position. The first arm, the second arm, and the third arm are arranged so as to be separated from the rotating member when the rotating member is arranged at the third position.

2. The holding device according to claim 1, characterized in that: The rotating machine and the rotating member moving cylinder are separated in the axial direction of the shaft. The rotating member and the moving member move in the axial direction between the rotating machine and the rotating member moving cylinder.

3. A holding device, characterized in that: have: a first arm and a second arm that clamp a workpiece by moving in opposite directions to each other; a third arm that moves in a direction intersecting the directions in which the first arm and the second arm move and engages with the workpiece; a rotating member that contacts the first arm, the second arm, and the third arm and moves each arm; a rotating machine that rotates the rotating member; as well as A rotating member moving cylinder, which is used to move the rotating member to a first position, a second position, and a third position between the first position and the second position; A position detector for detecting a rotation angle of the rotating machine; as well as a control device for controlling the above-mentioned rotating machine, The first arm and the second arm are arranged so that when the rotating member is arranged in the first position, the first arm contacts one side of the rotating member and the second arm contacts the other side of the rotating member. The third arm is configured to contact the rotating member when the rotating member is configured in the second position. The first arm, the second arm, and the third arm are configured to be separated from the rotating member when the rotating member is configured in the third position. The control device includes a storage unit storing information related to the control of the rotating machine. The position detector detects the rotation angle of the rotating machine when the rotating member is arranged at one of the first position and the second position when the rotating member moves from the first position to the third position. The storage unit stores the rotation angle detected by the position detector. When the rotating member moves from the third position to the one position, the control device controls the rotation angle of the rotating machine so as to become the rotation angle stored in the storage unit.

4. A holding device, characterized in that: have: a first arm and a second arm that clamp a workpiece by moving in opposite directions to each other; a third arm that moves in a direction intersecting the directions in which the first arm and the second arm move and engages with the workpiece; a rotating member that contacts the first arm, the second arm, and the third arm and moves each arm; a rotating machine that rotates the rotating member; a rotating member moving cylinder for moving the rotating member to a first position, a second position, and a third position between the first position and the second position; and a moving member connected to the rotating member moving cylinder and pressing the rotating member to move the rotating member, The moving member includes a first pressing portion that presses the third arm when the rotating member is disposed at the first position, and a second pressing portion that presses the first arm and the second arm when the rotating member is disposed at the second position.

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