Hand and robot system

Abstract

The invention provides a hand. A hand (100) includes a hand body (2), a holder (3) that holds a workpiece, a connector (4) that connects the holder (3) to the hand body (2) in such a way that the relative position of the holder (3) with respect to the hand body (2) can be changed, and a restraint (9) that restrains the action of the connector (4). The restraining device (9) switches, by means of an opening / closing action, a restraining state in which the action of the connector (4) is restrained by coming into contact with the grip (3), and a release state in which the restraining of the action of the connector (4) is released by deviating from the grip (3).

Description

Technical Field

[0001] The present invention relates to hands and robotic systems. Background Art

[0002] Hands that hold a workpiece to perform work are well known. For example, Patent Document 1 discloses a hand that holds a component and inserts the held component into a hole of another component.

[0003] Patent Document 1: Japanese Patent Application Laid-Open No. 5-285747 Summary of the invention

[0004] However, in the hand operation as described above, the position accuracy of the hand has a great influence on the operation. For example, in the operation of inserting a component into a hole, when the position of the component and the hole are misaligned, the component insertion operation becomes difficult. In addition, when the insertion direction of the component and the axis of the hole are tilted, the component insertion operation also becomes difficult. This is not limited to the component insertion operation, but also applies to the operation of picking up components and arranging components in predetermined locations. Therefore, it is conceivable to improve the position accuracy of the hand. However, in order to improve the position accuracy of the hand, the load of sensing and control when performing the position control of the hand increases.

[0005] In view of the above, an object of the present invention is to facilitate work performed by hand.

[0006] The hand of the present invention includes a hand body, a gripper, a connector and a restraint, wherein the gripper grips a workpiece, the connector connects the gripper to the hand body in a manner that can change the relative position of the gripper with respect to the hand body, the restraint restrains the movement of the connector, and the restraint switches between a restrained state and a released state by an opening and closing action. In the restrained state, the movement of the connector is restrained by contacting the gripper, and in the released state, the movement of the connector is released from the restraint by moving away from the gripper.

[0007] The robot system of the present invention includes the hand, a robot arm and a control device, wherein the robot arm is connected to the hand, the control device controls the robot arm and the hand, and the control device enables the robot arm and the hand to perform an insertion operation, in which the workpiece held by the hand is inserted into a predetermined hole.

[0008] (Effects of the Invention)

[0009] According to the hand, work performed by the hand can be easily achieved.

[0010] According to the robot system, it is possible to easily realize work performed by hand. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 is a schematic diagram showing the structure of a robot system.

[0012] Figure 2 It is a three-dimensional picture of the hand.

[0013] Figure 3 This is a top view of the hand.

[0014] Figure 4 yes Figure 3 Cross-sectional view of the hand at line IV-IV.

[0015] Figure 5 yes Figure 3 Cross-sectional view of the hand at line VV.

[0016] Figure 6 It is a three-dimensional cross-sectional view of an eccentric connector.

[0017] Figure 7 is a perspective cutaway view of an inclined connector.

[0018] Figure 8 It is a cross-sectional view of the hand showing a state in which the gripper is moved in the second direction relative to the hand body.

[0019] Fig. 9 is a cross-sectional view of the hand showing a state in which the holder is rotated relative to the hand body around the first rotation axis.

[0020] Fig.10 It is a cross-sectional view of the hand showing a state in which the rectilinear actuator advances the gripper in the direction of the first reference axis.

[0021] Fig.11 It is a cross-sectional view of a hand showing a state in which the opening and closing actuator causes the fingers to open.

[0022] Fig.12 It is a side view of the hand.

[0023] Fig.13 This is the front view of the hand.

[0024] Fig.14 yes Fig.13 Sectional view of the hand at line XIV-XIV.

[0025] Fig.15 is a side view of the hand with the restraint in the released state.

[0026] Fig.16 : is a block diagram showing a schematic hardware structure of the control device.

[0027] Fig.17 It is a flowchart of the insert operation.

[0028] Fig.18 This is a schematic diagram of the hand when the contact action is completed, viewed from the front.

[0029] Fig.19 It is a schematic plan view showing the positional relationship between the workpiece and the hole when the contact action is completed.

[0030] Fig. 20 This is a diagram showing the hand when the introduction action is completed, viewed from the front.

[0031] Fig.21 It is a schematic plan view showing the positional relationship between the workpiece and the hole at the start of the insertion operation.

[0032] Fig. 22 This is a diagram showing the hand during insertion as viewed from the front.

[0033] Fig.23 It is a schematic plan view showing the positional relationship between the workpiece and the hole during the insertion operation.

[0034] Fig.24 This is a diagram showing the hand when the insertion action is completed, as seen from the front.

[0035] Fig.25 This is a schematic diagram of a hand when the contact action with a hole extending in the horizontal direction is completed, as viewed from the front.

[0036] Fig.26 This is a schematic diagram of a hand when the introduction operation into a hole extending in the horizontal direction is completed, as viewed from the front.

[0037] Fig. 27 This is a schematic diagram of a hand seen from the front during an insertion operation into a hole extending in a horizontal direction. DETAILED DESCRIPTION

[0038] Hereinafter, exemplary embodiments will be described in detail with reference to the drawings.

[0039] =Robot System=

[0040] Figure 1 is a schematic diagram showing the structure of the robot system 1000 .

[0041] The robot system 1000 includes a robot 110 and a control device 130. The robot 110 includes a robot arm 120 and a hand 100. The control device 130 controls the robot arm 120 and the hand 100. The hand 100 is connected to the robot arm 120 (specifically, the front end of the robot arm 120). The hand 100 holds a workpiece and performs various processes. For example, the control device 130 causes the robot arm 120 and the hand 100 to perform an insertion operation, in which the workpiece held by the hand 100 is inserted into a predetermined hole. Here, the insertion of the workpiece also includes the case of pressing the workpiece into the hole or engaging the workpiece in the threaded hole.

[0042] The robot 110 is, for example, an industrial robot. The robot 110 operates or moves the hand 100 through the robot arm 120. The hand 100 is one of the so-called end effectors. The hand 100 holds a workpiece. In addition, the hand 100 may pick up the workpiece again or combine the workpiece with other workpieces.

[0043] The robot arm 120 includes a plurality of links 121, a plurality of joints 122, and a plurality of motors. Each joint 122 rotatably connects two adjacent links 121. The plurality of motors respectively drive the plurality of joints 122 to rotate. Each motor is, for example, a servo motor.

[0044] =Hand=

[0045] Figure 2 is a three-dimensional diagram of the hand 100 . Figure 3 is a top view of the hand 100 . Figure 4 yes Figure 3 A cross-sectional view of the hand 100 at line IV-IV. Figure 5 yes Figure 3 It should be noted that in each figure, in order to more easily illustrate the structure, the illustration of some elements is omitted. The same is true in the following figures.

[0046] The hand 100 includes a hand body 2, a gripper 3 and a connector 4, wherein the gripper 3 grips a workpiece, and the connector 4 connects the gripper 3 to the hand body 2. A predetermined first reference axis X is defined in the hand body 2. A predetermined second reference axis α is defined in the gripper 3. The connector 4 connects the gripper 3 to the hand body 2 in a manner that can change the relative position of the gripper 3 relative to the hand body 2. The connector 4 includes an eccentric connector 41 and an inclined connector 47, wherein the eccentric connector 41 supports the gripper 3 in a manner that the second reference axis α can be eccentric relative to the first reference axis X, and the inclined connector 47 supports the gripper 3 in a manner that the second reference axis α can be inclined relative to the first reference axis X.

[0047] The hand 100 can make the workpiece held by the gripper 3 move straight in the direction of the first reference axis X while rotating it around the first reference axis X. In this way, the hand 100 can, for example, insert the workpiece into a hole or engage the workpiece in a threaded hole. Hereinafter, the side where the gripper 3 advances from the hand body 2 in the direction of the first reference axis X is referred to as the "advance side" or "front end side", and the side where the gripper 3 retreats toward the hand body 2 in the direction of the first reference axis X is referred to as the "retreat side" or "body side".

[0048] The hand 100 also includes a restraint 9 that restrains the movement of the connector 4. The restraint 9 switches between a restraint state and a release state. In the restraint state, the movement of the connector 4 is restrained by contacting the gripper 3, and in the release state, the restraint on the movement of the connector 4 is released by moving away from the gripper 3. The restraint 9 switches between the restraint state and the release state by an opening and closing action. When the restraint 9 is in a restraint state, the movement of the connector 4 is restrained, and the relative position of the gripper 3 with respect to the hand body 2 becomes unchangeable. When the restraint 9 is in a release state, the connector 4 can move freely, and the relative position of the gripper 3 with respect to the hand body 2 becomes changeable.

[0049] like Figure 4 As shown, the hand 100 further includes a first buffer 10 , which absorbs the force acting on the holder 3 in the direction of the first reference axis X.

[0050] like Figure 2 As shown, the hand body 2 is a box-shaped housing. The hand body 2 is roughly in the shape of a rectangular parallelepiped. The hand body 2 has a straight-moving actuator 6, a rotating actuator 7, and an opening and closing actuator 8. The straight-moving actuator 6 makes the gripper 3 move straight relative to the hand body 2 in the direction of the first reference axis X, the rotating actuator 7 makes the gripper 3 rotate around the second reference axis α, and the opening and closing actuator 8 makes the gripper 3 open and close. The hand body 2 accommodates the straight-moving actuator 6, the rotating actuator 7, the opening and closing actuator 8, and the first buffer 10.

[0051] -Holder-

[0052] like Figure 4 As shown, the gripper 3 has a base 31, a plurality of fingers 32, and an action mechanism 33. The plurality of fingers are supported by the base 31, and the action mechanism 33 enables the plurality of fingers 32 to perform an opening and closing action. Figure 2 As shown, the holder 3 has three fingers 32 .

[0053] like Figure 2 As shown in FIG. 1 , the base 31 is generally cylindrical. Specifically, the base 31 includes a first tube 34a, a second tube 34b, a ceiling 34c, and a bottom 34d. The ceiling 34c is Figure 4 As shown in etc. Figure 4 As shown in the figure, the first tube 34a and the second tube 34b are roughly cylinders extending coaxially with the second reference axis α as the axis. The ceiling 34c is arranged at one end of the first tube 34a in the direction of the second reference axis α. The ceiling 34c is a roughly circular disk centered on the second reference axis α. An opening is formed in the approximate center of the ceiling 34c. The first tube 34a and the ceiling 34c are formed as a single unit. The second tube 34b is installed on the ceiling 34c. The bottom 34d is installed on the other end of the first tube 34a in the direction of the second reference axis α. The bottom 34d is a roughly circular disk centered on the second reference axis α. The bottom 34d is formed separately with the first tube 34a and the ceiling 34c, and is installed on the first tube 34a.

[0054] The bottom 34d is formed with three slits 34e that penetrate the bottom 34d in the thickness direction and extend in the radial direction with the second reference axis α as the center. Figure 4 One slit 34e is shown in FIG. The slits 34e are arranged at equal intervals (ie, at 120-degree intervals) in the circumferential direction around the second reference axis α.

[0055] The finger 32 is supported by the bottom 34d so as to be slidable along the slit 34e. Specifically, the finger 32 has a first end 32a supported by the base 31 and a second end 32b in contact with the workpiece. The first end 32a is arranged inside the base 31 and is slidably engaged with the bottom 34d. In this way, the finger 32 is supported by the base 31 so as to be movable in the radial direction centered on the second reference axis α. The finger 32 extends from the base 31 substantially parallel to the second reference axis α.

[0056] The three fingers 32 are arranged at equal intervals (i.e., 120 degree intervals) in the circumferential direction around the second reference axis α. The three fingers 32 open and close by moving away from and approaching each other in the radial direction around the second reference axis α. The fingers 32 hold the workpiece at the second end 32b.

[0057] The action mechanism 33 has a plurality of connecting rods 36 connected to the plurality of fingers 32, a feed screw 37 extending around the second reference axis α and rotating around the second reference axis α, and a block 38 engaged with the feed screw 37 and connected to the plurality of connecting rods 36. The action mechanism 33 is a so-called connecting rod mechanism.

[0058] A link 36 is connected to each finger 32. One end of the link 36 is rotatably connected to the finger 32 (specifically, the first end 32a).

[0059] The feed screw 37 and the block 38 form a so-called feed screw mechanism. The feed screw 37 is disposed in the base 31. The feed screw 37 extends around the second reference axis α as an axis and is supported by the bottom 34d so as to be rotatable around the second reference axis α.

[0060] A plurality of links 36 are connected to the block 38. Specifically, the end of the link 36 opposite to the end connected to the finger 32 is rotatably connected to the block 38. That is, one end of the link 36 is connected to the finger 32, and the other end of the link 36 is connected to the block 38. The finger 32 passes through the slit 34c and cannot rotate around the second reference axis α relative to the base 31. Therefore, the block 38 connected to the three fingers 32 via the link 36 cannot rotate around the second reference axis α relative to the base 31.

[0061] When the feed screw 37 rotates, the block 38 moves in the direction of the second reference axis α. When the block 38 moves in the direction of the second reference axis α, the connecting rod 36 is linked, and thus the finger 32 moves in the radial direction centered on the second reference axis α. When the block 38 approaches the bottom 34d, the finger 32 moves outward in the radial direction. On the other hand, when the block 38 moves away from the bottom 34d, the finger 32 moves inward in the radial direction.

[0062] -Connectors-

[0063] The connector 4 connects the base 31 to the hand body 2. Figure 4 As shown, the connector 4 is connected to the rotary actuator 7 of the hand body 2. The connector 4 is arranged inside the second tube 34b. Figure 6 It is a perspective cross-sectional view of the eccentric connector 41 .

[0064] The eccentric connector 41 is connected to the rotary actuator 7. In detail, the rotary actuator 7 has a rotary shaft 71 with the first reference axis X as the axis center, which will be described later. A flange-shaped first disk 71c and a second disk 71d extending in a plane substantially orthogonal to the first reference axis X are provided at the first end 71a, which is the end closer to the connector 4, of the two ends of the rotary shaft 71. The first disk 71c is arranged on the front end side of the first end 71a compared with the second disk 71d. The eccentric connector 41 is connected to the first end 71a of the rotary shaft 71.

[0065] like Figure 4 , Figure 5 as well as Figure 6As shown, the eccentric connector 41 has an eccentric body 42, which is movably connected to the rotating shaft 71 in a direction approximately orthogonal to the first reference axis X. The eccentric body 42 has a substantially cylindrical barrel 42a, a substantially disc-shaped ceiling 42b, and a substantially disc-shaped bottom 42c. The eccentric body 42 is formed into a substantially cylindrical box shape as a whole. The barrel 42a, the ceiling 42b, and the bottom 42c are coaxially arranged. That is, the barrel 42c extends with the axis C as the axis center, and the axis centers of the ceiling 42b and the bottom 42c are also the axis C. An opening is formed in the approximate center of the ceiling 42b. An opening is formed in the approximate center of the bottom 42c. The eccentric body 42 accommodates the first disc 71c of the rotating shaft 71. That is, the rotating shaft 71 passes through the opening of the ceiling 42b, and the first disc 71c is arranged between the ceiling 42b and the bottom 42c. The first disc 71c is approximately parallel to each of the ceiling 42b and the bottom 42c. That is, the axis C becomes roughly parallel to the first reference axis X. Between the ceiling 42b and the first disk 71c, a plurality of rolling elements 43 are arranged in a circumferential direction with the first reference axis X as the center. Similarly, between the bottom 42c and the first disk 71c, a plurality of rolling elements 43 are arranged in a circumferential direction with the first reference axis X as the center. In this example, the rolling elements 43 are balls. The rolling of the plurality of rolling elements 43 enables the eccentric body 42 to move in a direction roughly orthogonal to the first reference axis X relative to the rotation axis 71. At this time, the eccentric body 42 moves in parallel in a direction roughly orthogonal to the first reference axis X without changing its posture (i.e., maintaining the axis C and the first reference axis X roughly parallel). The eccentric body 42 can move in parallel within the range where the cylinder 42a contacts the first disk 71c. However, the eccentric body 42 cannot move in the direction of the first reference axis X relative to the rotation axis 71.

[0066] like Figure 4 as well as Figure 5 As shown, the holder 3 is connected to the eccentric body 42 via the inclined connector 47. Therefore, the holder 3 can also move in a direction substantially orthogonal to the first reference axis X with respect to the rotation axis 71 together with the eccentric body 42.

[0067] The eccentric connector 41 also has a second joint 45. The second joint 45 connects the rotating shaft 71 and the holder 3. The second joint 45 is a joint that connects two eccentric and substantially parallel shafts, and transmits rotation between the two eccentric shafts. In this example, the second joint 45 transmits the rotation of the rotating shaft 71 to the holder 3 in a state where the second reference axis α is eccentric with respect to the first reference axis X. In this example, the second joint 45 is a so-called cross slide joint.

[0068] In detail, Figure 6As shown, the second joint 45 has a second disk 71d as a first hub, an insert 45a, and an eccentric body 42 as a second hub. The eccentric body 42, the insert 45a, and the second disk 71d are arranged in this order in the direction of the first reference axis X from the base 31 side. The second disk 71d is formed integrally with the rotating shaft 71 (specifically, the first end 71a). The second disk 71d and the insert 45a are connected to each other movably in the first direction B1 that is substantially orthogonal to the first reference axis X. The insert 45a and the eccentric body 42 are connected to each other movably in the second direction B2 that is substantially orthogonal to the first reference axis X and substantially orthogonal to the first direction B1. That is, the eccentric body 42 is configured to be able to move freely in a plane that is substantially orthogonal to the first reference axis X relative to the second disk 71d. At this time, the eccentric body 42 moves parallel to the direction that is substantially orthogonal to the first reference axis X without changing its posture. However, the eccentric body 42 cannot rotate around the first reference axis X relative to the second disk 71d.

[0069] like Figure 4 , Figure 5 as well as Figure 6 As shown, the rotating shaft 71 passes through the insert 45a and enters the inner side of the eccentric body 42. The second disk 71d rotates integrally with the rotating shaft 71. When the second disk 71d rotates around the first reference axis X, the eccentric body 42 rotates in conjunction with the second disk 71d because it is configured to be unable to rotate relative to the second disk 71d. At this time, when the axis C of the eccentric body 42 is eccentric relative to the first reference axis X, the eccentric body 42 rotates while relatively parallel moving in a direction substantially orthogonal to the first reference axis X, so that the eccentric body 42 rotates around the axis C while maintaining the positional relationship between the axis C and the first reference axis X. That is, the rotation around the first reference axis X input to the second disk 71d is output to the eccentric body 42 as the rotation around the axis C eccentric relative to the first reference axis X. Since the gripper 3 is connected to the eccentric body 42, when the eccentric body 42 rotates, the gripper 3 also rotates together.

[0070] Figure 7 : is a three-dimensional cross-sectional view of the tilt connector 47. The tilt connector 47 has a third joint 48. The third joint 48 connects the rotating shaft 71 and the holder 3. The third joint 48 is a joint that connects two axes that are tilted to each other (that is, two axes with a deflection angle), and transmits rotation between the two tilted axes. In this example, the third joint 48 transmits the rotation of the rotating shaft 71 to the holder 3 in a state where the second reference axis α is tilted to the first reference axis X. That is, the tilt connector 47 not only connects the holder 3 so that it can be tilted relative to the rotating shaft 71, but also transmits the rotation of the rotating shaft 71 to the holder 3 in a state where the second reference axis α is tilted to the first reference axis X. In this example, the third joint 48 connects the rotating shaft 71 and the holder 3 with the eccentric connector 41 interposed therebetween.

[0071] The third joint 48 has a connecting element 48a. The connecting element 48a is roughly annular. The connecting element 48a has a first rotation axis D1 and a second rotation axis D2 extending in directions roughly orthogonal to each other. In this example, the first rotation axis D1 and the second rotation axis D2 exist in the same plane, and the first rotation axis D1 and the second rotation axis D2 are roughly orthogonal to each other. The eccentric body 42 is rotatably connected to the connecting element 48a around the first rotation axis D1. In more detail, the bottom 42c of the eccentric body 42 is connected to the connecting element 48a. The first rotation axis D1 is roughly orthogonal to the axis C of the eccentric body 42. In addition, the base 31 is rotatably connected to the connecting element 48a around the second rotation axis D2. In more detail, the ceiling 34c of the base 31 is connected to the connecting element 48a. The second rotation axis D2 is roughly orthogonal to the second reference axis α of the holder 3.

[0072] The connecting element 48a can freely rotate around the first rotation axis D1 relative to the eccentric body 42, and the base 31 can freely rotate around the second rotation axis D2 relative to the connecting element 48a. Therefore, the gripper 3 can freely tilt relative to the axis C of the eccentric body 42. The third joint 48 is a so-called universal joint, and more specifically, the third joint 48 is a cross-axis universal joint.

[0073] The operation of the connector 4 configured as above will be described.

[0074] First, the operation of the eccentric connector 41 is described. When a force that causes the hand body 2 and the gripper 3 to move relative to each other in a direction substantially orthogonal to the first reference axis X acts on at least one of the hand body 2 and the gripper 3, the eccentric body 42 moves relative to the rotation axis 71 in a direction substantially orthogonal to the first reference axis X through the rolling of a plurality of rolling bodies 43. At the same time, the insert 45a moves relative to the second disk 71d in the first direction B1, and at the same time, the second hub, i.e., the eccentric body 42, moves relative to the insert 45a in the second direction B2. Due to the movement of the eccentric body 42, the eccentric body 42 moves relative to the hand body 2 in a manner that the axis C is eccentric relative to the first reference axis X. The gripper 3 connected to the eccentric body 42 moves relative to the hand body 2 in a manner that the second reference axis α is eccentric relative to the first reference axis X.

[0075] Figure 8 1 is a cross-sectional view of the hand 100 showing a state in which the gripper 3 moves in the second direction B2 relative to the hand body 2. The eccentric body 42 moves parallel to the second direction B2 relative to the insert 45a. Along with this, the gripper 3 connected to the eccentric body 42 also moves parallel to the second direction B2 relative to the insert 45a. As a result, the second reference axis α of the gripper 3 is eccentric relative to the first reference axis X of the hand body 2.

[0076] Similarly, the insert 45a can move in parallel to the first direction B1 relative to the second disk 71d. Along with this, the holder 3 connected to the second disk 71d via the insert 45a can also move in parallel to the first direction B1 relative to the second disk 71d. By combining such parallel movement of the holder 3 in the first direction B1 and parallel movement in the second direction B2, the holder 3 can move in parallel to any direction substantially orthogonal to the first reference axis X, eccentric to the first reference axis X.

[0077] It should be noted that when the gripper 3 is fixed and the hand body 2 moves relative to the gripper 3, the hand body 2 moves relative to the gripper 3 in a direction approximately orthogonal to the first reference axis X, so that the second reference axis α is eccentric relative to the first reference axis X.

[0078] Furthermore, when the rotating shaft 71 rotates around the first reference axis X in a state where the second reference axis α, i.e., the axis C, is constrained at a position eccentric to the first reference axis X, the insert 45a moves relative to the second disk 71d and the eccentric body 42 moves relative to the insert 45a, so that the eccentric body 42 rotates around the axis C while the eccentric state between the axis C and the first reference axis X remains unchanged. In this way, the eccentric connector 41 not only makes the holder 3 eccentric to the first reference axis X, but also transmits the rotation of the rotating shaft 71 around the first reference axis X to the eccentric body 42 as a rotation around the axis C eccentric from the first reference axis X. Since the holder 3 is connected to the eccentric body 42, the holder 3 also rotates around the second reference axis α eccentric from the first reference axis X.

[0079] In this way, the first disk 71c and the rolling element 43 and the second joint 45 respectively connect the eccentric body 42, that is, the gripper 3, to the rotating shaft 71 so as to be able to move parallel to the direction substantially orthogonal to the first reference axis X. Here, the first disk 71c and the rolling element 43 also have the function of transmitting the load in the direction of the first reference axis X of the gripper 3 and the workpiece to the rotating shaft 71 so as not to cause the load to act only on the second joint 45. As described above, the second joint 45 also has the function of transmitting the rotation between the first reference axis X and the axis C which are eccentric to each other.

[0080] Next, the operation of the tilt connector 47 is described. When a force that causes the hand body 2 and the gripper 3 to tilt relative to each other acts on at least one of the hand body 2 and the gripper 3, the base 31 freely rotates around the first rotation axis D1 and the second rotation axis D2 relative to the eccentric body 42. As a result, the second reference axis α of the base 31 freely tilts relative to the axis C of the eccentric body 42. The axis C of the eccentric body 42 is approximately parallel to the first reference axis X. Therefore, the second reference axis α of the base 31 tilts relative to the first reference axis X.

[0081] Fig. 91 is a cross-sectional view of the hand 100 showing a state in which the gripper 3 rotates about the first rotation axis D1 relative to the hand body 2. The base 31 and the connecting element 48a rotate about the first rotation axis D1 relative to the eccentric body 42. As a result, the second reference axis α of the gripper 3 is tilted relative to the first reference axis X of the hand body 2.

[0082] Likewise, the base 31 can rotate relative to the connecting element 48a around the second rotation axis D2. As a result, the second reference axis α of the holder 3 is aligned with the first reference axis X of the hand body 2. Fig. 9 Tilt in different directions. The holder 3 can be tilted in any direction relative to the first reference axis X by combining the rotation of the holder 3 about the first rotation axis D1 and the rotation about the second rotation axis D2.

[0083] It should be noted that, when the gripper 3 is fixed and the hand body 2 moves relative to the gripper 3 , the hand body 2 moves relative to the gripper 3 , so that the second reference axis α is inclined relative to the first reference axis X.

[0084] Here, when the second reference axis α is maintained constrained in a state of being inclined relative to the first reference axis X, when the eccentric body 42 rotates around the axis C, the connecting element 48a rotates relative to the eccentric body 42 around the first rotation axis D1 and the base 31 rotates relative to the connecting element 48a around the second rotation axis D2, so that the base 31 rotates around the second reference axis α without changing its posture.

[0085] In this way, the connector 4 can support the holder 3 eccentrically with respect to the first reference axis X, and can support the holder 3 tilted with respect to the first reference axis X. In addition, when the second reference axis α of the holder 3 is eccentric or tilted with respect to the first reference axis X, the connector 4 transmits the rotation of the rotation axis 71 around the first reference axis X as a rotation around the second reference axis α to the holder 3.

[0086] -Linear actuator and rotary actuator-

[0087] The linear actuator 6 moves the rotating shaft 71 in the direction of the first reference axis X to move the gripper 3 in a straight line. The rotary actuator 7 rotates the rotating shaft 71 around the first reference axis X to rotate the gripper 3 around the first reference axis X. In this example, a part of the elements are common between the linear actuator 6 and the rotary actuator 7. Furthermore, a part of the elements are common between the linear actuator 6 and the opening and closing actuator 8. A part of the elements are common between the rotary actuator 7 and the opening and closing actuator 8.

[0088] The straight-moving actuator 6 has a second motor 61 and a straight-moving transmission 67. The second motor 61 generates a driving force, and the straight-moving transmission 67 transmits the driving force of the second motor 61 to the gripper. The second motor 61 is an example of a straight-moving driving source. The straight-moving transmission 67 has a first gear train 62, a feed screw mechanism 63, a rotating shaft 71, and a gear box 72. The first gear train 62 transmits the driving force (i.e., rotational torque) of the second motor 61. Figure 4 As shown, most of the linear actuator 6 is arranged inside the hand body 2 .

[0089] like Figure 4 as well as Figure 5 As shown, the rotating shaft 71 is a roughly cylindrical shape extending with the first reference axis X as the axis. The rotating shaft 71 is movable in the direction of the first reference axis X and is rotatably supported around the first reference axis X by a bearing 12, and the bearing 12 is mounted on the hand body 2. In the rotating shaft 71, one end in the direction of the first reference axis X is called the first end 71a, and the other end in the direction of the first reference axis X is called the second end 71b. The first end 71a is the end on the forward side in the direction of the first reference axis X. The second end 71b is the end on the backward side in the direction of the first reference axis X. The rotating shaft 71 passes through the bottom 21 of the hand body 2. The first end 71a is arranged on the outside of the hand body 2.

[0090] A flange-shaped first disk 71c and a second disk 71d extending in a plane substantially perpendicular to the first reference axis X are provided at the first end 71a of the rotating shaft 71. The first disk 71c is disposed closer to the front end of the first end 71a than the second disk 71d.

[0091] like Figure 3 As shown, the second motor 61 is disposed inside the hand body 2. The second motor 61 is, for example, a servo motor and is provided with an encoder. In addition, a current sensor is provided in the driver of the second motor 61. The second motor 61 is supported by the hand body 2.

[0092] like Figure 3As shown, the first gear train 62 is arranged inside the hand body 2. The first gear train 62 has a plurality of gears rotatably supported by the hand body 2. The first gear train 62 includes a first gear 62a, a second gear 62b, a third gear 62c, a fourth gear 62d, a fifth gear 62e, a sixth gear 62f and a seventh gear 62g. The first gear 62a, the second gear 62b, the third gear 62c, the fourth gear 62d, the fifth gear 62e and the sixth gear 62f are arranged in this order and mesh with each other. The seventh gear 62g meshes with the fourth gear 62d. The first gear 62a is mounted on the output shaft of the second motor 61. The first gear 62a is a driving gear. The second gear 62b, the third gear 62c, the fourth gear 62d, the fifth gear 62e, the sixth gear 62f and the seventh gear 62g are driven gears that transmit the driving force of the second motor 61. The second gear 62b and the sixth gear 62f transmit the driving force of the second motor 61 to the feed screw 64 of the linear actuator 6. The fourth gear 62d transmits the driving force of the second motor 61 to the ball spline 73c of the rotary actuator 7. The seventh gear 62g transmits the driving force of the second motor 61 to the feed screw 910 of the restraining actuator 93 described later. The third gear 62c and the fifth gear 62e are so-called intermediate gears (i.e., idler gears).

[0093] like Figure 4 As shown, the linear actuator 6 has two sets of feed screw mechanisms 63. The feed screw mechanism 63 has a feed screw 64 and a nut 65, which is a linear element engaged with the feed screw 64.

[0094] The axis F of each feed screw 64 extends substantially parallel to the first reference axis X. One feed screw 64 is non-rotatably connected to the second gear 62b of the first gear train 62. The other feed screw 64 is non-rotatably connected to the sixth gear 62f of the first gear train 62. That is, the two feed screws 64 rotate integrally around the axis F with the second gear 62b and the sixth gear 62f, respectively.

[0095] The nut 65 meshes with the feed screw 64. The nut 65 is housed in the gear box 72. The nut 65 is prevented from rotating about the axis F by the gear box 72. The nut 65 has a body 65a formed in a cylindrical shape and a flange 65b provided on the body 65a.

[0096] The nut 65 is elastically pressed against the gear box 72 in the direction of the axis F, that is, the direction of the first reference axis X, by the first buffer 10. The first buffer 10 is a spring. Specifically, the first buffer 10 is a coil spring. Figure 4, the first buffer 10 is simplified in the figure. The first buffer 10 is arranged on the forward side of the first reference axis X direction relative to the flange 65b. The first buffer 10 is compressed between the flange 65b and the gear box 72. The first buffer 10 presses the gear box 72 toward the forward side of the first reference axis X direction by elastic force. The gear box 72 is pressed against the nut 65 toward the forward side of the first reference axis X direction. In this way, when the nut 65 moves in the direction of the axis F, the gear box 72 also moves in the direction of the axis F, i.e., the first reference axis X direction, together with the nut.

[0097] Gear box 72 by Figure 3 The linear guide 28 shown is supported movably in the direction of the first reference axis X. Figure 3 In the figure, the gear box 72 is omitted. The hand body 2 has two linear guides 28 extending in the direction of the first reference axis X. The gear box 72 is supported by the linear guides 28 and therefore cannot rotate around the first reference axis X. Figure 4 As shown, the rotating shaft 71 is connected to the gear box 72 so as to be rotatable around the first reference axis X and immovable in the direction of the first reference axis X. When the gear box 72 moves in the direction of the first reference axis X, the rotating shaft 71 also moves in the direction of the first reference axis X together with the gear box 72.

[0098] The rotary actuator 7 includes a second motor 61 that generates a driving force and a rotary shaft 71 that extends around the first reference axis X and is rotated around the first reference axis X by the driving force of the second motor 61. The rotary actuator 7 also includes a first gear train 62 that transmits the driving force of the second motor 61, a gear box 72, and a second gear train 73 that further transmits the driving force of the second motor 61 from the first gear train 62 to the rotary shaft 71. That is, the second motor 61, the first gear train 62, the rotary shaft 71, and the gear box 72 of the rotary actuator 7 are common to the linear actuator 6. The second motor 61 is an example of a rotary drive source.

[0099] like Figure 5 As shown, the second gear train 73 includes a first gear 73a and a second gear 73b. The first gear 73a and the second gear 73b are meshed with each other.

[0100] The first gear 73a is connected to the fourth gear 62d of the first gear train 62 via the ball spline 73c. ​​The axis G of the ball spline 73c extends substantially parallel to the first reference axis X. The ball spline 73c is non-rotatably connected to the fourth gear 62d. That is, the ball spline 73c rotates around the axis G integrally with the fourth gear 62d.

[0101] The first gear 73a is connected to the ball spline 73c so as to be non-rotatable around the axis G and to be movable in the direction of the axis G. Furthermore, the first gear 73a is supported by the gear box 72 so as to be non-movable in the direction of the axis G and to be rotatable around the axis G. That is, when the ball spline 73c rotates around the axis G, the first gear 73a rotates around the axis G relatively to the gear box 72 and integrally with the ball spline 73c. ​​Furthermore, when the gear box 72 moves in the direction of the first reference axis X, i.e., the direction of the axis G, the first gear 73a also moves in the direction of the axis G integrally with the gear box 72. Even if the position of the first gear 73a in the direction of the axis G changes, it rotates around the axis G integrally with the ball spline 73c.

[0102] The second gear 73b is connected to the rotating shaft 71 so as to be non-rotatable around the first reference axis X and non-movable in the direction of the first reference axis X. The second gear 73b rotates around the first reference axis X integrally with the rotating shaft 71 and moves in the direction of the first reference axis X integrally with the rotating shaft 71. The second gear 73b is connected to a portion of the rotating shaft 71 located inside the gear box 72. When the gear box 72 moves in the direction of the first reference axis X, the rotating shaft 71 and the second gear 73b also move in the direction of the first reference axis X together with the gear box 72. At this time, the meshing of the first gear 73a and the second gear 73b is maintained.

[0103] The operations of the linear actuator 6 and the rotary actuator 7 configured in this manner will be described. Fig.10 1 is a cross-sectional view of the hand 100 showing a state in which the rectilinear actuator 6 advances the gripper 3 in the first reference axis X direction.

[0104] When the second motor 61 is driven, the rotational driving force of the second motor 61 is transmitted to the two feed screws 64 of the linear actuator 6 and the ball spline 73c of the rotary actuator 7 via the first gear train 62. That is, when the feed screw 64 rotates, the ball spline 73c also rotates.

[0105] When the feed screw 64 rotates about the axis F, as shown in FIG. Fig.10 As shown, the nut 65 meshed with the feed screw 64 moves in the direction of the axis F. When the nut 65 moves in the direction of the axis F, the gear box 72 also moves in the direction of the axis F, that is, the first reference axis X. When the gear box 72 moves in the direction of the first reference axis X, the rotating shaft 71 also moves in the direction of the first reference axis X together with the gear box 72. At this time, the first gear 73a and the second gear 73b move in the direction of the first reference axis X together with the rotating shaft 71 and the gear box 72 while maintaining mutual meshing.

[0106] When the ball spline 73c rotates about the axis G, the first gear 73a rotates integrally with the ball spline 73c about the axis G. The rotation of the first gear 73a causes the second gear 73b to rotate about the first reference axis X, and the rotation shaft 71 rotates integrally with the second gear 73b.

[0107] Thus, the rotating shaft 71 moves in the direction of the first reference axis X while rotating around the first reference axis X. The holder 3 is connected to the rotating shaft 71 via the connector 4. Therefore, the holder 3 moves in the direction of the first reference axis X together with the rotating shaft 71. In addition, the holder 3 moves while rotating around the second reference axis α.

[0108] -Opening and closing actuator-

[0109] The opening and closing actuator 8 includes a first motor 81 that generates a driving force and an opening and closing shaft 84 that extends around the first reference axis X and is rotated around the first reference axis X by the driving force of the first motor 81. The opening and closing actuator 8 opens and closes the finger 32 by operating the action mechanism 33. The opening and closing actuator 8 includes a first belt transmission mechanism 85, a second belt transmission mechanism 86, and a gear box 72. That is, the gear box 72 of the opening and closing actuator 8 is common to the linear actuator 6 and the rotary actuator 7. The first motor 81 is an example of an opening and closing drive source.

[0110] like Figure 5 As shown, the opening and closing shaft 84 is a substantially cylindrical shape extending with the first reference axis X as the axis center. In the opening and closing shaft 84, one end in the direction of the first reference axis X is referred to as the first end 84a, and the other end in the direction of the first reference axis X is referred to as the second end 84b. The first end 84a is the end on the forward side in the direction of the first reference axis X. The second end 84b is the end on the backward side in the direction of the first reference axis X. The opening and closing shaft 84 is inserted into the rotating shaft 71 so as to be rotatable around the first reference axis X. The second end 84b protrudes outward from the second end 71b of the rotating shaft 71.

[0111] Furthermore, the opening and closing shaft 84 is supported by the gear box 72 so as to be rotatable about the first reference axis X and not movable in the direction of the first reference axis X. Therefore, when the gear box 72 moves in the direction of the first reference axis X, the opening and closing shaft 84 also moves in the direction of the first reference axis X together with the gear box 72. At this time, since the rotating shaft 71 also moves in the direction of the first reference axis X together with the gear box 72, the relative positions of the rotating shaft 71 and the opening and closing shaft 84 in the direction of the first reference axis X do not change.

[0112] The opening and closing shaft 84 is inserted into the rotating shaft 71 . Since the rotating shaft 71 is supported by the hand body 2 via the bearing 12 , the opening and closing shaft 84 is substantially supported by the hand body 2 .

[0113] like Figure 3 As shown, the first motor 81 is arranged inside the hand body 2. It should be noted that the first motor 81 is arranged at a position different from the first gear train 62 in the direction of the first reference axis X. The first motor 81 is, for example, a servo motor and is provided with an encoder. In addition, a current sensor is provided in the driver of the first motor 81. The first motor 81 is supported by the hand body 2.

[0114] like Figure 3 As shown, the first belt transmission mechanism 85 has a first pulley 85a, a second pulley 85b and a timing belt 85c. The first pulley 85a is mounted on the output shaft of the first motor 81. Figure 5 As shown, the second pulley 85b is connected to the ball spline 87. The ball spline 87 has an axis E that is substantially parallel to the first reference axis X. The ball spline 87 is supported by the hand body 2 so as to be rotatable around the axis E. The second pulley 85b is connected to the ball spline 87 so as not to be rotatable around the axis E and not to be movable in the direction of the axis E. The timing belt 85c is wound around the first pulley 85a and the second pulley 85b. The driving force of the first motor 81 is transmitted to the second pulley 85b via the first pulley 85a and the timing belt 85c. The ball spline 87 rotates around the axis E integrally with the second pulley 85b.

[0115] like Figure 5 As shown, the second belt transmission mechanism 86 has a third pulley 86a, a fourth pulley 86b and a timing belt 86c. The third pulley 86a is connected to the ball spline 87 so as to be non-rotatable around the axis E and movable in the direction of the axis E. The third pulley 86a is supported by the gear box 72 so as to be non-rotatable around the axis E and non-movable in the direction of the axis E. The fourth pulley 86b is connected to the opening and closing shaft 84 so as to be non-rotatable around the first reference axis X and non-movable in the direction of the first reference axis X. In detail, the fourth pulley 86b is connected to the second end 84b of the opening and closing shaft 84 protruding from the rotating shaft 71. The fourth pulley 86b is supported by the gear box 72 so as to be non-rotatable around the first reference axis X and non-movable in the direction of the first reference axis X. The timing belt 86c is wound around the third pulley 86a and the fourth pulley 86b. The rotation of the ball spline 87 around the axis E is transmitted to the fourth pulley 86b via the third pulley 86a and the timing belt 86c.

[0116] In this way, the driving force of the first motor 81 is transmitted to the opening and closing shaft 84 via the first belt transmission mechanism 85 and the second belt transmission mechanism 86. In this way, the opening and closing shaft 84 rotates around the first reference axis X. Since the opening and closing shaft 84 is inserted into the rotating shaft 71 so as to be rotatable around the first reference axis X, the opening and closing shaft 84 rotates around the first reference axis X independently from the rotating shaft 71. In addition, the opening and closing shaft 84 and the second belt transmission mechanism 86 are supported by the gear box 72 so as not to move in the direction of the first reference axis X. Therefore, when the gear box 72 moves in the direction of the first reference axis X, the opening and closing shaft 84 and the second belt transmission mechanism 86 move in the direction of the first reference axis X together with the gear box 72. At this time, the third pulley 86a moves in the direction of the axis E along the ball spline 87. Even if the opening and closing shaft 84 and the second belt transmission mechanism 86 move in the direction of the first reference axis X together with the gear box 72, the driving force of the first motor 81 is transmitted to the opening and closing shaft 84 via the first belt transmission mechanism 85 and the second belt transmission mechanism 86.

[0117] like Figure 5 As shown, the connector 4 has a power transmission device 5, which transmits the driving force of the opening and closing actuator 8 to the holder 3. The power transmission device 5 transmits the driving force of the opening and closing actuator 8 to the holder 3 in a state where the second reference axis α is eccentric or inclined relative to the first reference axis X. The power transmission device 5 includes a first joint 51, which connects the opening and closing shaft 84 and the holder 3. Specifically, the first joint 51 connects the opening and closing shaft 84 and the action mechanism 33 of the holder 3.

[0118] The first joint 51 transmits the rotation of the opening and closing shaft 84 to the actuating mechanism 33, i.e., the holder 3, when the second reference axis α is eccentric or tilted relative to the first reference axis X. The first joint 51 is a joint that transmits rotation even when a deviation such as an angular deviation or an eccentricity occurs between the two axes. Specifically, the first joint 51 includes a first ball coupling 52 and a second ball coupling 53. In addition, the first ball coupling 52 and the second ball coupling 53 are simplified in the diagram. The first ball coupling 52 and the second ball coupling 53 are joints that respectively have the functions of a universal joint (i.e., a universal joint) and a spline, and are joints that transmit rotation even when a deviation such as an angular deviation or an eccentricity occurs between the two axes.

[0119] The first ball coupling 52 connects the first end 84a of the opening and closing shaft 84 and the second ball coupling 53. The first ball coupling 52 transmits the rotation of the opening and closing shaft 84 around the first reference axis X to the second ball coupling 53. The second ball coupling 53 connects the first ball coupling 52 and the feed screw 37 of the action mechanism 33. The second ball coupling 53 transmits the rotation of the first ball coupling 52 to the feed screw 37 as a rotation around the second reference axis α.

[0120] Even if the second reference axis α is eccentric or tilted relative to the first reference axis X, the first ball coupling 52 and the second ball coupling 53 can absorb the eccentricity and angle between the first reference axis X and the second reference axis α, and transmit the rotation around the first reference axis X as the rotation around the second reference axis α.

[0121] The operation of the opening and closing actuator 8 and the power transmission device 5 configured as above will be described. Fig.11 FIG. 1 is a cross-sectional view of a hand 100 showing a state in which the opening and closing actuator 8 causes the finger 32 to open. Fig.11 In the embodiment, the holder 3 is in a state of retreating in the direction of the first reference axis X.

[0122] When the first motor 81 is in operation, Figure 3 as well as Figure 5 As shown, the rotational driving force of the first motor 81 is transmitted to the ball spline 87 via the first pulley 85a, the synchronous belt 85c and the second pulley 85b. When the ball spline 87 rotates around the axis E, the third pulley 86a connected to the ball spline 87 rotates around the axis E. The rotation of the third pulley 86a is transmitted to the opening and closing shaft 84 via the synchronous belt 86c and the fourth pulley 86b. In this way, the opening and closing shaft 84 rotates around the first reference axis X. The rotation of the opening and closing shaft 84 around the first reference axis X is transmitted to the feed screw 37 of the action mechanism 33 as a rotation around the second reference axis α via the power transmission device 5. When the feed screw 37 rotates around the second reference axis α, the block 38 moves in the direction of the second reference axis α. At this time, as shown in Fig.11 As shown in FIG. 3 , when the block 38 approaches the bottom 34d, the finger 32 moves outward in the radial direction around the second reference axis α. Figure 4 As shown in FIG. 1 , when the block 38 moves away from the bottom 34d, the fingers 32 move radially inward. In this way, the opening and closing actuator 8 opens and closes the fingers 32. As a result, the plurality of fingers 32 either hold the workpiece or release the workpiece. At this time, the plurality of fingers 32 open and close in a manner such that the distances from the second reference axis α are the same as each other. In other words, the plurality of fingers 32 open and close with the second reference axis α as the center.

[0123] The direction of the movement of the block 38 in the direction of the second reference axis α, that is, whether the finger 32 is open or closed, is switched by the rotation direction of the first motor 81. In addition, the radial position of the finger 32 centered on the second reference axis α, that is, the degree of opening and closing of the finger 32, is detected based on the encoder output of the first motor 81. In addition, the rotation torque of the first motor 81 when the three fingers 32 are opened and closed is detected based on the detection result of the current sensor.

[0124] Here, when the linear actuator 6 moves the rotating shaft 71 and the gripper 3 in the direction of the first reference axis X, the opening and closing shaft 84 and the second belt transmission mechanism 86 supported by the gear box 72 also move in the direction of the first reference axis X together with the rotating shaft 71 and the like. The state in which the driving force of the first motor 81 can be transmitted to the opening and closing shaft 84 via the first belt transmission mechanism 85 and the second belt transmission mechanism 86 is maintained. That is, even if the rotating shaft 71 and the gripper 3 move in the direction of the first reference axis X, the fingers 32 of the gripper 3 can be opened and closed by the driving force of the first motor 81.

[0125] However, when the rotation shaft 71 and the gripper 3 are moved in the direction of the first reference axis X by the linear actuator 6, the gripper 3 is rotated around the first reference axis X by the rotary actuator 7. That is, the base 31 and the finger 32 rotate around the first reference axis X. At this time, since the feed screw 37 does not rotate around the first reference axis X when the opening and closing shaft 84 does not rotate around the first reference axis X, the base 31 rotates relatively around the first reference axis X relative to the feed screw 37. As a result, the block 38 moves in the direction of the second reference axis α, and the open and closed state of the finger 32 changes.

[0126] Therefore, when the rotating shaft 71 moves in the direction of the first reference axis X and the finger 32 is maintained in the open and closed state, the first motor 81 cooperates with the rotation of the gripper 3 around the first reference axis X to rotate the opening and closing shaft 84 around the first reference axis X. Specifically, the first motor 81 is torque-controlled, and the torque of the first motor 81 is controlled to be constant. In this way, the finger 32 rotates around the first reference axis X while maintaining the open and closed state (for example, the finger 32 maintains the state of holding the workpiece), and at the same time, moves in the direction of the first reference axis X.

[0127] And, if Figure 8 As shown in FIG. 1 , since the holder 3 is supported by the connector 4, the second reference axis α of the holder 3 may be eccentric relative to the first reference axis X. Alternatively, as shown in FIG. Fig. 9 As shown, the second reference axis α of the holder 3 can be tilted relative to the first reference axis X. Even in this case, the connection between the opening and closing axis 84 and the actuating mechanism 33 is maintained by deformation of the first ball coupling 52 and the second ball coupling 53. In addition, the rotation of the opening and closing axis 84 around the first reference axis X is transmitted to the actuating mechanism 33 as a rotation around the second reference axis α via the first ball coupling 52 and the second ball coupling 53. Here, since the first joint 51 includes two joints, namely the first ball coupling 52 and the second ball coupling 53, the first joint 51 can flexibly correspond to the eccentricity and tilt of the first reference axis X and the second reference axis α.

[0128] -First Buffer-

[0129] The first buffer 10 elastically supports the holder 3 in the direction of the first reference axis X. The first buffer 10 absorbs the force acting on the holder 3 in the direction of the first reference axis X by elastically supporting the holder 3 .

[0130] As mentioned above, the first buffer 10 is a spring. Figure 4 As shown, the first buffer 10 elastically connects the nut 65 and the gear box 72 of the feed screw mechanism 63. Since the hand 100 has two sets of feed screw mechanisms 63, it has two first buffers 10. Specifically, the first buffer 10 is accommodated in the gear box 72. The nut 65 and the gear box 72 are elastically connected in a manner that the gear box 72 is displaceable relative to the nut 65 to the rear side in the direction of the first reference axis X. The opening and closing shaft 84 and the rotating shaft 71 are connected to the gear box 72. The holder 3 is connected to the opening and closing shaft 84 and the rotating shaft 71 via the connector 4. That is, the first buffer 10 substantially supports the holder 3 in a manner that the holder 3 is displaceable to the rear side in the direction of the first reference axis X.

[0131] When a force acts on the holder 3 (for example, the finger 32) toward the retreat side in the direction of the first reference axis X in such a first buffer 10, the force is transmitted from the holder 3 to the nut 65 via the connector 4, the rotating shaft 71, the gear box 72, and the first buffer 10. At this time, the first buffer 10 undergoes elastic deformation, that is, compression deformation, and the gear box 72 moves toward the retreat side in the direction of the first reference axis X. The opening and closing shaft 84, the rotating shaft 71, and the holder 3 also move toward the retreat side in the direction of the first reference axis X together with the gear box 72. In this way, the force acting on the holder 3 is absorbed by the first buffer 10.

[0132] - Restraints -

[0133] Fig.12 is a side view of the hand 100 . Fig.13 1 is a front view of the hand 100. The restraint 9 has a transmission rubber, and restrains the movement of the connector 4 by elastically holding the gripper 3 in a restrained state. In this example, the restraint 9 restrains the movement of the connector 4 in a state where the first reference axis X and the second reference axis α are arranged in a straight line. For ease of explanation, the Y axis and the Z axis are set to be approximately orthogonal to the first reference axis X. The Y axis and the Z axis are approximately orthogonal to each other. That is, three orthogonal axes are formed by the first reference axis X, the Y axis, and the Z axis.

[0134] The restraint 9 has a first retainer 91 and a second retainer 92 and a restraint actuator 93, wherein the first retainer 91 and the second retainer 92 contact the gripper 3 in the restrained state, and the restraint actuator 93 causes the first retainer 91 and the second retainer 92 to perform an opening and closing action. The first retainer 91 and the second retainer 92 switch between contact with the gripper 3 and separation from the gripper 3 by performing an opening and closing action. The first retainer 91 and the second retainer 92 perform an opening and closing action in a direction intersecting the first reference axis X direction. In this example, the first retainer 91 and the second retainer 92 perform an opening and closing action by moving in a direction approximately orthogonal to the first reference axis X direction. In more detail, the first retainer 91 and the second retainer 92 open and close in a direction approximately parallel to the Z axis. Hereinafter, the opening and closing direction of the first retainer 91 and the second retainer 92 is referred to as the "opening and closing direction Z". The restraint 9 elastically holds the holder 3 in the opening and closing direction Z of the first retainer 91 and the second retainer 92 by the elastic force of the transmission rubber 97. That is, the holder 3 held by the restraint restraint 9 can be displaced in the opening and closing direction Z of the first retainer 91 and the second retainer 92 by the elastic deformation of the transmission rubber 97.

[0135] Furthermore, the restrainer 9 has a second buffer 98, and the second buffer 98 elastically supports the first retainer 91 and the second retainer 92 in the direction of the first reference axis X. That is, the first retainer 91 and the second retainer 92 are displaceable in the direction of the first reference axis X by the second buffer 98. As a result, the gripper 3 held by the restrainer 9 in the restrained state can be displaced in the direction of the first reference axis X by the action of the second buffer 98. The second buffer 98 is an example of a buffer.

[0136] The following is a detailed description of the restrainer 9. Fig.12 As shown, the first retainer 91 and the second retainer 92 are arranged opposite to each other with the first reference axis X sandwiched therebetween. The first retainer 91 and the second retainer 92 are arranged on the outside of the holder 3 in the opening and closing direction Z. The first retainer 91 and the second retainer 92 are arranged on the front end side of the first reference axis X direction compared to the bottom 21. The first retainer 91 and the second retainer 92 extend in approximately the Y-axis direction, respectively. The first retainer 91 and the second retainer 92 open and close in a manner that changes the interval between each other, specifically, the first retainer 91 and the second retainer 92 open and close in a manner that changes the interval in the opening and closing direction Z. The first retainer 91 and the second retainer 92 hold the holder 3 by clamping the holder 3 from the outside.

[0137] Fig.14 yes Fig.13 The cross-sectional view of the hand 100 at the XIV-XIV line of FIG. Fig.14 In the figure, the interior of the holder 3, i.e., the connector 4, is omitted. The first retainer 91 contacts the holder 3 at least at two locations in the contact state. The second retainer 92 contacts the holder at one location in the contact state. Specifically, the first retainer 91 has a first contact surface 91a and a second contact surface 91b in contact with the holder 3. The first contact surface 91a and the second contact surface 91b are substantially planes. The normal direction of the first contact surface 91a and the normal direction of the second contact surface 91b intersect with each other. In other words, the first contact surface 91a and the second contact surface 91b are neither parallel to each other nor in the same plane. The second retainer 92 has a third contact surface 92c in contact with the holder 3. The third contact surface 92c is substantially plane. The first contact surface 91a, the second contact surface 91b, and the third contact surface 92a are in point contact or line contact with the second cylinder 34b of the holder 3. It should be noted that each of the first contact surface 91 a , the second contact surface 91 b , and the third contact surface 92 a may be a flat surface or a curved surface.

[0138] The constraint actuator 93 has a second motor 61 and a constraint transmission 94, wherein the second motor 61 generates a driving force, and the constraint transmission 94 connects the second motor 61 and the first retainer 91 and the second retainer 92 to transmit the driving force of the second motor 61 to the first retainer 91 and the second retainer 92. The second motor 61 is an example of a constraint driving source. It should be noted that, in this example, a part of the elements between the constraint actuator 93 and the straight-moving actuator 6 are common.

[0139] The transmission rubber 97 is included in the restraining transmission 94. Specifically, the restraining transmission 94 includes a first transmission 95, a second transmission 96, and a transmission rubber 97, wherein the first transmission 95 receives the driving force from the second motor 61, the second transmission 96 transmits the driving force to the first holder 91 and the second holder 92, and the transmission rubber 97 elastically connects the first transmission 95 and the second transmission 96. The transmission rubber 97 is an example of a first elastic member.

[0140] like Fig.13 As shown, the first transmission 95 has a first gear train 62, a feed screw 910, a block 911 and an arm 912, wherein the first gear train 62 transmits the driving force (i.e., rotational torque) of the second motor 61, the feed screw 910 extends substantially parallel to the first reference axis X, the block 911 is engaged with the feed screw 910, and the arm 912 is mounted on the block 911.

[0141] like Figure 3As shown, the seventh gear 62g is included in the first gear train 62. The driving force of the second motor 61 is transmitted to the seventh gear 62g via the first gear 62a, the second gear 62b, the third gear 63c and the fourth gear 62d.

[0142] like Fig.13 As shown, the axis I of the feed screw 910 extends substantially parallel to the first reference axis X. The feed screw 910 is non-rotatably connected to the seventh gear 62g of the first gear train 62. The feed screw 910 rotates integrally with the seventh gear 62g about the axis I. The feed screw 910 is rotatably supported by the base 21 about the axis I.

[0143] The block 911 is engaged with the feed screw 910. The feed screw 910 and the block 911 form a feed screw mechanism.

[0144] The arm 912 is fixedly mounted on the block 911. The arm 912 is configured to be non-rotatable around the axis I. Specifically, the arm 912 extends from the block 911 to both sides in a direction intersecting the axis I. The arm 912 is supported by the hand body 2 so as to be movable in the direction of the first reference axis X. Fig.13 As shown, the arm 912 extends from the axis I to both sides of the Y-axis direction. Fig.12 As shown, both ends 912a of the arm 912 in the extension direction are bent from the Y-axis direction to the opening and closing direction Z. Both ends 912a of the arm 912 are mounted on a pair of first guide members 23. The pair of first guide members 23 are arranged at positions facing each other with the first reference axis X sandwiched therebetween. Fig.13 as well as Fig.14 As shown, the hand body 2 has two side walls 22A and a side wall 22B facing each other with the first reference axis X sandwiched therebetween. The side walls 22A and 22B are substantially orthogonal to the Y-axis direction. A pair of first guide members 23 are respectively arranged on the side walls 22A and the side walls 22B. The first guide member 23 has a block 23a and a track 23b, the block 23a is mounted on the arm 912, specifically, the block 23a is mounted on the end 912a, and the track 23b guides the block 23a in the direction of the first reference axis X. By moving the block 23a in the direction of the first reference axis X along the track 23b, the arm 912 moves parallel to the direction of the first reference axis X, that is, moves without changing its posture. The arm 912 becomes capable of moving only in the direction of the first reference axis X.

[0145] The arm 912 is mounted on the first guide member 23 so as to be unable to rotate about the axis I. Therefore, the block 911 is also unable to rotate about the axis I. That is, the block 911 and the arm 912 can rotate about the axis I relative to the feed screw 910, but cannot rotate about the axis I relative to the hand body 2. Therefore, when the feed screw 910 rotates about the axis I, the block 911 and the arm 912 move in the direction of the axis I, i.e., the direction of the first reference axis X, without rotating about the axis I.

[0146] like Fig.12 As shown in FIG. 13 , the second transmission device 96 forms a linkage mechanism. The first retainer 91 and the second retainer 92 are respectively connected to the second transmission device 96. The constraint transmission device 94 has a pair of second transmission devices 96. The pair of second transmission devices 96 are arranged at positions opposite to each other with the first reference axis X clamped therebetween. The pair of second transmission devices 96 are arranged at positions corresponding to the pair of first guide members 23. Specifically, the pair of second transmission devices 96 are respectively arranged on the two side walls 22A and 22B of the hand body 2. It should be noted that the second transmission device 96 arranged on the side wall 22A and the second transmission device 96 arranged on the side wall 22B are reversed left and right based on the first connecting rod 96a. In addition, the pair of second transmission devices 96 have the same structure as each other. The first retainer 91 is connected to each of the pair of second transmission devices 96. The second retainer 92 is connected to each of the pair of second transmission devices 96.

[0147] The second transmission device 96 has a first connecting rod 96a, a second connecting rod 96b, a third connecting rod 96c, a fourth connecting rod 96d, a fifth connecting rod 96c, a sixth connecting rod 96f and a seventh connecting rod 96g. The first connecting rod 96a, the second connecting rod 96b, the third connecting rod 96c and the fourth connecting rod 96d form a four-section connecting rod. The first connecting rod 96a, the fifth connecting rod 96c, the sixth connecting rod 96f and the seventh connecting rod 96g form another four-section connecting rod. In other words, the first connecting rod 96a is a common connecting rod in one four-section connecting rod and another four-section connecting rod.

[0148] In detail, one end of the second link 96b is rotatably connected to the first link 96a, and the other end of the second link 96b is rotatably connected to the third link 96c. One end of the fourth link 96d is rotatably connected to the first link 96a, and the other end of the fourth link 96d is rotatably connected to the third link 96c. One end of the fifth link 96e is rotatably connected to the first link 96a, and the other end of the fifth link 96e is rotatably connected to the sixth link 96f. One end of the seventh link 96g is rotatably connected to the first link 96a, and the other end of the seventh link 96g is rotatably connected to the sixth link 96f. The first link 96a, the third link 96c, and the sixth link 96f extend substantially parallel to the first reference axis X. The first link 96a is disposed between the third link 96c and the sixth link 96f.

[0149] The first link 96a is a link to which the driving force from the first transmission device 95 is input. The first link 96a is supported by the hand body 2 so as to be movable in the direction of the first reference axis X. Fig.13As shown, the first connecting rod 96a is mounted on the second guide member 24. A pair of second guide members 24 are respectively arranged on two opposite side walls 22A and 22B of the hand body 2. The second guide member 24 has a block 24a and a track 24b, the block 24a is mounted with the first connecting rod 96a, and the track 24b guides the block 24a in the direction of the first reference axis X. The track 24b is formed integrally with the track 23b of the first guide member 23. That is, the track 23b and the track 24b are formed with a common track. The first connecting rod 96a moves parallel to the first reference axis X direction by the block 24a moving along the track 24b in the direction of the first reference axis X, that is, moves without changing the posture. The first connecting rod 96a is made to be able to move only in the direction of the first reference axis X.

[0150] like Fig.12 as well as Fig.13 As shown, the third link 96c is a link that transmits the driving force to the first retainer 91. The third link 96c is supported by the hand body 2 so as to be movably in the opening and closing direction Z. Specifically, the third link 96c is mounted on the third guide 25. A pair of third guides 25 are respectively arranged on two opposing side walls 22A and 22B of the hand body 2. The third guide 25 has a block 25a and a track 25b, the block 25a is mounted with the third link 96c, and the track 25b guides the block 25a in the opening and closing direction Z. The third link 96c moves in parallel in the opening and closing direction Z by the block 25a moving along the track 25b in the opening and closing direction Z, that is, moves without changing the posture. The third link 96c becomes movable only in the opening and closing direction Z.

[0151] The sixth link 96f is a link that transmits the driving force to the second retainer 92. The sixth link 96f is supported by the hand body 2 so as to be movable in the opening and closing direction Z. Specifically, the sixth link 96f is mounted on the fourth guide 26. A pair of fourth guides 26 are respectively arranged on two opposing side walls 22A and side walls 22B of the hand body 2. The fourth guide 26 has a block 26a and a track 26b, the block 26a being mounted with the sixth link 96f, and the track 26b guiding the block 26a in the opening and closing direction Z. The sixth link 96f moves parallel to the opening and closing direction Z by the block 26a moving along the track 26b in the opening and closing direction Z, that is, moves without changing the posture. The sixth link 96f becomes movable only in the opening and closing direction Z.

[0152] The arm 912 is connected to the first link 96a. Specifically, the arm 912 is connected to the first link 96a via the transmission rubber 97. Fig.12As shown in FIG. 1 , the transmission rubber 97 is mounted on the arm 912, and more specifically, the transmission rubber 97 is mounted on the end 912a of the arm 912. The transmission rubber 97 is arranged in the engagement hole 96h formed in the first link 96a. When the arm 912 moves in the direction of the first reference axis X, the transmission rubber 97 moves in the direction of the first reference axis X together with the arm 912, and presses the first link 96a in the direction of the first reference axis X. In this way, the driving force is transmitted from the arm 912 to the first link 96a via the transmission rubber 97.

[0153] Furthermore, a bolt 99 is provided on the first connecting rod 96a, and the bolt 99 adjusts the dimension of the first reference axis X direction of the engaging hole 96h. The bolt 99 penetrates the first connecting rod 96a in the first reference axis X direction, and a part of the bolt 99 is arranged in the engaging hole 96h. In this example, the bolt head is located in the engaging hole 96h. The bolt head of the bolt 99 is arranged at one end in the first reference axis X direction in the engaging hole 96h. That is, in the first reference axis X direction, the transmission rubber 97 and the bolt heads of the bolt 99 are arranged. One end of the transmission rubber 97 arranged in the engaging hole 96h in the first reference axis X direction contacts the inner peripheral surface of the engaging hole 96h. The other end of the transmission rubber 97 in the first reference axis X direction contacts the bolt head of the bolt 99.

[0154] The position of the bolt 99 in the first reference axis X direction in the engaging hole 96h is adjusted by adjusting the amount of screwing of the bolt 99 into the first connecting rod 96a. The interval between the inner peripheral surface of the engaging hole 96h and the bolt 99 in the first reference axis X direction becomes the substantial dimension of the engaging hole 96h in the first reference axis X direction. When the bolt 99 moves the engaging hole 96h inwardly in the first reference axis X direction, the substantial dimension of the engaging hole 96h in the first reference axis X direction becomes smaller. On the other hand, when the bolt 99 moves the engaging hole 96h outwardly in the first reference axis X direction, the substantial dimension of the engaging hole 96h in the first reference axis X direction becomes larger.

[0155] When the dimension of the transmission rubber 97 in the direction of the first reference axis X is larger than the interval between the inner circumferential surface of the engaging hole 96h and the bolt 99 in the direction of the first reference axis X, one end of the transmission rubber 97 in the direction of the first reference axis X contacts the inner circumferential surface of the engaging hole 96h, and the other end of the transmission rubber 97 in the direction of the first reference axis X contacts the bolt 99. In this state, when the screwing amount of the bolt 99 is adjusted, the amount of compression deformation of the transmission rubber 97 in the direction of the first reference axis X changes. The greater the amount of compression deformation of the transmission rubber 97, the more difficult it is for the transmission rubber 97 to be compressed and deformed. In other words, when the compression deformation of the transmission rubber 97 changes, the substantial rigidity of the transmission rubber 97 changes. Here, the substantial rigidity of the transmission rubber 97 does not refer to the rigidity of the transmission rubber 97 in the natural state, that is, the state where no external force acts, but refers to the rigidity of the state where the transmission rubber 97 connects the arm 912 and the first link 96a.

[0156] Alternatively, when the dimension of the transmission rubber 97 in the direction of the first reference axis X is smaller than the interval between the inner circumference of the engaging hole 96h and the bolt 99 in the direction of the first reference axis X, the transmission rubber 97 can move in the engaging hole 96h in the direction of the first reference axis X. Therefore, the movement of the first link 96a in the direction of the first reference axis X can be delayed for the movement of the arm 912 in the direction of the first reference axis X. For example, when the transmission rubber 97 starts to move in the opposite direction of the first reference axis X from the state of contacting the bolt 99, the transmission rubber 97 contacts the inner circumference of the engaging hole 96h after moving a little. That is, the first link 96a does not move immediately even if the transmission rubber 97 moves. When the screwing amount of the bolt 99 is adjusted, the delay amount between the movement of the arm 912 and the movement of the first link 96a is adjusted.

[0157] The first holder 91 is connected to the third link 96c. The first holder 91 is connected to each of the third link 96c of one second transmission 96 and the third link 96c of the other second transmission 96. The second holder 92 is connected to the sixth link 96f. The second holder 92 is connected to the sixth link 96f of one second transmission 96 and the sixth link 96f of the other second transmission 96. In detail, the first holder 91 and the second holder 92 are connected to the third link 96c and the sixth link 96f via the second buffer 98.

[0158] The second buffer 98 includes a guide 98a that guides the first holder 91 and the second holder 92 so as to be displaceable in the direction of the first reference axis X, and a second spring 98b that elastically supports the first holder 91 and the second holder 92 along the guide 98a. The second spring 98b is an example of a second elastic member.

[0159] In this example, the second buffer 98 includes four guides 98a and four second springs 98b. A guide 98a is provided at each of the two third links 96c and the two sixth links 96f. In detail, a guide 98a is provided at one end of the third link 96c, specifically, at the end close to the holder 3 in the first reference axis X direction. A guide 98a is provided at one end of the sixth link 96f, specifically, at the end close to the holder 3 in the first reference axis X direction. All guides 98a have the same structure as each other. For example, the guide 98a is a ball spline. The guide 98a has a spline shaft 98c and an outer cylinder 98d embedded in the spline shaft 98c. In the guide 98a corresponding to the first retainer 91, the spline shaft 98c is installed on the third link 96c, and the outer cylinder 98d is installed on the first retainer 91. In the guide member 98a corresponding to the second retainer 92, the spline shaft 98c is mounted on the sixth connecting rod 96f, and the outer cylinder 98d is mounted on the second retainer 92. The spline shaft 98c extends in the direction of the first reference axis X. A ball is arranged between the spline shaft 98c and the outer cylinder 98d. In this way, the outer cylinder 98d slides smoothly along the spline shaft 98c in the direction of the first reference axis X. A stopper is provided at the front end of the spline shaft 98c to prevent the outer cylinder 98d from falling off.

[0160] The second spring 98b is provided on each guide 98a. For example, the second spring 98b is a coil spring. The guide 98a is inserted into the second spring 98b. The second spring 98b corresponding to the first retainer 91 is arranged in a compressed state between the third link 96c and the first retainer 91. Therefore, the second spring 98b applies force to the first retainer 91 toward the front end side of the spline shaft 98c by elastic force. The first retainer 91 is located at the farthest position from the third link 96c in the first reference axis X direction under normal circumstances, that is, when the external force in the first reference axis X direction does not act on the first retainer 91. The second spring 98b corresponding to the second retainer 92 is arranged in a compressed state between the sixth link 96f and the second retainer 92. Therefore, the second spring 98b applies force to the second retainer 92 toward the front end side of the spline shaft 98c by elastic force. The second holder 92 is located at the position farthest from the sixth link 96 f in the first reference axis X direction in a normal situation, that is, when no external force in the first reference axis X direction acts on the second holder 92 .

[0161] The operation of the restraining device 9 configured in this manner will be described. Fig.15 It is a side view of the hand 100 with the restraint 9 in the released state. Fig.15 The first holder 91 and a part of the second holder 92 are shown in cross section. Fig.15 The dotted arrows in show the movements of the various elements of the hand 100 when the restraint 9 is transferred from the released state to the restrained state.

[0162] First, the action of the restraint 9 when it changes from the released state to the restrained state is described. In the released state of the restraint 9, the first retainer 91 and the second retainer 92 are opened, and the restraint 9 is in a state of being separated from the gripper 3. At this time, the gripper 3 is in a state of moving forward from the hand body 2 to the front end side in the direction of the first reference axis X due to the straight-moving actuator 6.

[0163] When the second motor 61 of the constraint actuator 93 is operated, the rotational driving force of the second motor 61 is transmitted to the feed screw 910 via the first gear train 62. When the feed screw 910 rotates around the axis I, the arm 912 moves in the direction of the axis I, that is, the direction of the first reference axis X, together with the block 911 meshed with the feed screw 910. At this time, the rotation direction of the second motor 61 is set so that the arm 912 moves to the body side in the direction of the first reference axis X.

[0164] When the arm 912 moves toward the main body side in the direction of the first reference axis X, the first link 96a of the second transmission device 96 is pressed by the transmission rubber 97 and moves toward the main body side in the direction of the first reference axis X. When the first link 96a moves toward the main body side in the direction of the first reference axis X, the third link 96c and the sixth link 96f move in a direction to close to each other in the opening and closing direction Z in conjunction with the first link 96a. The first retainer 91 and the second retainer 92 also move toward a direction to close to each other in the opening and closing direction Z together with the third link 96c and the sixth link 96f. It should be noted that the third link 96c, the sixth link 96f, the first retainer 91 and the second retainer 92 do not move toward the first reference axis X, but only move toward the opening and closing direction Z.

[0165] Since the second motor 61 is also the driving source of the linear actuator 6, when the constraint actuator 93 is actuated, the linear actuator 6 is also actuated. That is to say, the gripper 3 is linked with the opening and closing actions of the first retainer 91 and the second retainer 92, and moves in the direction of the first reference axis X. Specifically, when the first retainer 91 and the second retainer 92 perform a closing action, the gripper 3 moves toward the main body side in the direction of the first reference axis X. As the first retainer 91 and the second retainer 92 close in the opening and closing direction Z, the gripper 3 penetrates deeply between the first retainer 91 and the second retainer 92 in the direction of the first reference axis X.

[0166] Finally, the first retainer 91 and the second retainer 92 contact the second tube 34b of the holder 3. Fig.12 As shown, the second tube 34b completely enters between the first holder 91 and the second holder 92 in the direction of the first reference axis X. In this way, the first holder 91 and the second holder 92 hold the holder 3 by clamping the second tube 34b in the opening and closing direction Z.

[0167] Here, even if the first retainer 91 and the second retainer 92 contact the second cylinder 34b, the second motor 61 may not stop immediately. The second motor 61 may continue to operate and continue to move the arm 912 toward the main body side in the direction of the first reference axis X. Since the first retainer 91 and the second retainer 92 cannot move in the closing direction of the opening and closing direction Z, the first link 96a cannot move toward the main body side in the direction of the first reference axis X. When the arm 912 moves toward the main body side in the direction of the first reference axis X, the transmission rubber 97 is compressed and deformed. In this way, the rigidity of holding the gripper 3 by the first retainer 91 and the second retainer 92 is improved. In this way, by further moving the arm 912 toward the main body side in the direction of the first reference axis X after the first retainer 91 and the second retainer 92 contact the second cylinder 34b, the pressing force of the transmission rubber 97 by the arm 912 on the first link 96a is adjusted, and as a result, the pressing force of the first retainer 91 and the second retainer 92 on the gripper 3 is adjusted. Of course, the movement of the arm 912 may be stopped immediately when the first retainer 91 and the second retainer 92 come into contact with the second tube 34 b .

[0168] The first retainer 91 and the second retainer 92 constrain the movement of the gripper 3 to constrain the movement of the eccentric connector 41 and the inclined connector 47. Specifically, the first retainer 91 and the second retainer 92 hold the gripper 3 to prevent the gripper 3 from moving in a direction substantially orthogonal to the first reference axis X and the gripper 3 from moving in a direction in which the second reference axis α is inclined relative to the first reference axis X. Figure 4 As shown, the first reference axis X and the second reference axis α are arranged in a straight line. In this way, the restrainer 9 restrains the movement of the eccentric connector 41 and the inclined connector 47 in a state where the first reference axis X and the second reference axis α are arranged in a straight line through the contact between the first retainer 91 and the second retainer 92 and the holder 3.

[0169] like Fig.14 As shown, in the restrained state of the restrainer 9, the first contact surface 91a and the second contact surface 91b of the first retainer 91 are in contact with the second tube 34b, and the third contact surface 92a of the second retainer 92 is in contact with the second tube 34b. In other words, the gripper 3 is supported at least at three locations by the first retainer 91 and the second retainer 92. As a result, in the restrained state, the positioning accuracy of the gripper 3 in the plane substantially orthogonal to the first reference axis X is improved.

[0170] Next, the action of the restraint device 9 when it changes from the restrained state to the released state will be described. Fig.12 , 13As shown in FIG. 14, in the restrained state of the restraint 9, the first retainer 91 and the second retainer 92 are closed and in contact with the gripper 3. At this time, the gripper 3 retreats toward the hand body 2 through the straight actuator 6, and the second cylinder 34b as a whole enters between the first retainer 91 and the second retainer 92 in the direction of the first reference axis X. It should be noted that when the restrained state is transferred to the released state, the various elements of the hand 100 move toward the Fig.15 The dashed arrow in the figure indicates movement in the opposite direction.

[0171] When the second motor 61 of the constraint actuator 93 is actuated, the rotational driving force of the second motor 61 is transmitted to the feed screw 910 via the first gear train 62. At this time, the rotation direction of the second motor 61 is set to the opposite direction to that when the constraint 9 is in the constraint state. When the feed screw 910 rotates around the axis I, the arm 912 moves together with the block 911 meshed with the feed screw 910 toward the front end side in the direction of the axis I, i.e., the direction of the first reference axis X.

[0172] When the arm 912 moves toward the front end side in the direction of the first reference axis X, the first link 96a of the second transmission device 96 is pressed by the transmission rubber 97 and moves toward the front end side in the direction of the first reference axis X. When the first link 96a moves toward the front end side in the direction of the first reference axis X, the third link 96c and the sixth link 96f move in the direction of opening and closing in the opening and closing direction Z in conjunction with it. The first retainer 91 and the second retainer 92 also move in the direction of opening and closing in the opening and closing direction Z together with the third link 96c and the sixth link 96f. As a result, the first retainer 91 and the second retainer 92 deviate from the second cylinder 34b of the gripper 3. It should be noted that the third link 96c, the sixth link 96f, the first retainer 91 and the second retainer 92 do not move in the direction of the first reference axis X, but only move in the opening and closing direction Z.

[0173] When the first retainer 91 and the second retainer 92 are in a state of not contacting the second cylinder 34b of the holder 3, the constraints on the movement of the holder 3 by the first retainer 91 and the second retainer 92 are released. In this way, the constraints on the movement of the eccentric connector 41 and the inclined connector 47 are also released. Specifically, the movement of the holder 3 in a direction substantially orthogonal to the first reference axis X and the movement of the holder 3 with the second reference axis α inclined relative to the first reference axis X become possible. In this way, the constraints on the movement of the holder 3 by the first retainer 91 and the second retainer 92 are released, and as a result, the constraints on the movement of the connector 4 are released.

[0174] As described above, the straight-acting actuator 6 also operates in conjunction with the constraint actuator 93. The gripper 3 moves in the direction of the first reference axis X in conjunction with the opening and closing actions of the first retainer 91 and the second retainer 92. When the first retainer 91 and the second retainer 92 perform an opening action, the gripper 3 moves toward the front end side in the direction of the first reference axis X. When the gripper 3 starts to move toward the front end side from the position that has retreated the most toward the main body side in the direction of the first reference axis X, the opening action of the first retainer 91 and the second retainer 92 starts, and the grip of the gripper 3 is released. As the gripper 3 moves away from the first retainer 91 and the second retainer 92 in the direction of the first reference axis X, the opening degree of the first retainer 91 and the second retainer 92 increases.

[0175] Since the constraining transmission 94 in the constraining device 9 thus constructed includes the transmission rubber 97, the first retainer 91 and the second retainer 92 in the constrained state elastically retain the gripper 3 in the opening and closing direction Z via the elastic force of the transmission rubber 97. In detail, in the state of being constrained by the constraining device 9, the position of the arm 912 is fixed. Although the position of the first link 96a depends on the position of the arm 912, it can be relatively displaced relative to the arm 912 by the elastic deformation of the transmission rubber 97. Therefore, when an external force acts on the first retainer 91 or the second retainer 92 in the opening direction of the opening and closing direction Z, the first link 96a can move in the direction of the first reference axis X, and the first retainer 91 and the second retainer 92 can move in the opening direction of the opening and closing direction Z. In this way, the constraining device 9 allows the gripper 3 and the connector 4 to be displaced to a certain extent in the opening and closing direction Z while constraining the movement of the gripper 3 and the connector 4.

[0176] At this time, the rigidity of the restraint 9 on the gripper 3 is adjusted by the screwing amount of the bolt 99 and the pressing force of the transmission rubber 97 on the first link 96a by the arm 912. As described above, the substantial rigidity of the transmission rubber 97 is adjusted by the screwing amount of the bolt 99. And, the pressing force of the first retainer 91 and the second retainer 92 on the gripper 3 is adjusted by the pressing force of the transmission rubber 97 on the first link 96a by the arm 912 in the restrained state of the restraint 9.

[0177] In addition, the first retainer 91 and the second retainer 92 are elastically supported by the second buffer 98 in the direction of the first reference axis X. That is, even in the restrained state by the restraint 9, the first retainer 91 and the second retainer 92 do not restrain the hand body 2 and the gripper 3 from relative movement in the direction of the first reference axis X. Therefore, even in the restrained state by the restraint 9, the first buffer 10 functions effectively.

[0178] Next, the control of the robot arm 120 and the hand 100 by the control device 130 will be described. Fig.16 Schematic hardware configuration of the control device 130 is shown in . The control device 130 includes a control unit 131 , a storage unit 132 , and a memory 133 .

[0179] The control unit 131 reads the program from the storage unit 132 into the memory 133 and expands it to realize various functions of the control device 130. The control unit 131 is formed by a processor such as a CPU (central processing unit). The control unit 131 can also be formed by an MCU (microcontroller unit), an MPU (microprocessor unit, an FPGA (field programmable gate array), a PLC (programmable logic controller), a system LSI (large scale integrated circuit), etc.

[0180] The control unit 131 controls the motion of the robot arm 120 by controlling the motor of the robot arm 120 . Also, the control unit 131 controls the motion of the hand 100 by controlling the first motor 81 and the second motor 61 .

[0181] The storage unit 132 stores programs executed by the control unit 131 and various data. The storage unit 132 is formed of a nonvolatile memory, a HDD (hard disk drive) or an SSD (solid state drive), etc. The memory 133 temporarily stores data. The memory 133 is formed of a volatile memory, for example.

[0182] Next, the specific control performed by the control device 130 will be described. The insertion operation will be described in which the workpiece W1 held by the hand 100 is inserted into the hole H formed in another workpiece W2. The workpiece W1 is cylindrical and extends with the axis M as the axis center. The hole H is a circular hole into which the workpiece W1 is inserted. The hole H extends in a substantially vertical direction with the axis N as the axis center. Fig.17 It is a flowchart of the insert operation.

[0183] First, in step S1, the control device 130 causes the robot arm 120 and the hand 100 to perform a gripping action of gripping the workpiece W1 with the gripper 3. Specifically, the control device 130 causes the three fingers 32 to open larger than the outer diameter of the workpiece W1. The control device 130 moves the robot arm 120 so that one end of the workpiece W1 is located on the inner side of the three fingers 32. Next, the control device 130 closes the three fingers 32. In this way, the three fingers 32 grip the workpiece W1. At this time, the axis M of the workpiece W1 is aligned with the second reference axis α. It should be noted that since the first reference axis X and the second reference axis α are aligned with each other, the axis M of the workpiece W1 is also aligned with the first reference axis X.

[0184] At this time, the control device 130 sets the restraint device 9 to the restrained state. That is, the first retainer 91 and the second retainer 92 hold the gripper 3, and the gripper 3 is in a state of being neither eccentric nor tilted relative to the first reference axis X of the hand body 2. In this way, the control device 130 can adjust the position of the gripper 3 with good accuracy during the gripping action or the next action.

[0185] Alternatively, the control device 130 may also cause the gripping action to be performed in the released state of the restraint 9. At that time, since the gripper 3 can be freely eccentric and tilted relative to the first reference axis X, the position of the gripper 3 is naturally adjusted even without accurately adjusting the positions of the gripper 3 and the workpiece W1, so that the gripper 3 can properly grip the workpiece W1.

[0186] After the workpiece W1 is gripped by the gripper 3 , the control device 130 causes the robot arm 120 and the hand 100 to perform a contact operation in which the workpiece W1 is brought into contact with the opening edge of the hole H in step S2 . Fig.18 This is a schematic diagram of the hand 100 when the contact action is completed, as viewed from the front. Fig.19 1 is a schematic plan view showing the positional relationship between the workpiece W1 and the hole H when the contact operation is completed.

[0187] Specifically, if Fig.18 As shown, the control device 130 moves the robot arm 120 so that the workpiece W1 contacts the opening edge of the hole H in a state where the first reference axis X and the second reference axis α are inclined relative to the axis N of the hole H. The robot arm 120 contacts the end edge of the workpiece W1 on the opposite side of the end gripped by the finger 32 with the opening edge of the hole H. Since the axis M of the workpiece W1 and the second reference axis α are aligned on a straight line, the axis M of the workpiece W1 is also inclined relative to the axis N of the hole H.

[0188] Since the workpiece W1 is a cylinder, the end edge of the workpiece W1 is circular. Since the hole H is a circular hole, the opening edge of the hole H is circular. When the circular end edge of the workpiece W1 contacts the circular opening edge of the hole H in a state where the axis M of the workpiece W1 is tilted relative to the axis N of the hole H, the workpiece W1 is in point contact or line contact with the opening edge of the hole H. In this example, the robot arm 120 is configured by arranging the axis M and the axis N in a twisted position, such as Fig.19 As shown, the workpiece W1 is brought into point contact with the opening edge of the hole H at point P.

[0189] During the contact operation, the restrainer 9 is in a restraining state, restraining the eccentric connector 41 and the inclined connector 47. In this way, the control device 130 can accurately adjust the position of the gripper 3, that is, the position of the workpiece W1. It should be noted that even in the restraining state of the restrainer 9, the first buffer 10 can effectively function due to the action of the second buffer 98, so that the impact of the workpiece W1 can be absorbed by the first buffer 10 and the second buffer 98 when the workpiece W1 contacts the opening edge of the hole H. Therefore, fast operation by the robot arm 120 and the hand 100 can be achieved.

[0190] Next, the control device 130 causes the hand 100 to perform a release action and an introduction action in step S3. The release action is an action of releasing the constraint of the connector 4 by the constraint 9. The introduction action is an action of partially inserting the workpiece W1 into the hole H by operating the rotary actuator 7 in a state where the first reference axis X is inclined relative to the axis N of the hole H. The hand 100 performs the release action and the introduction action at the same time. Fig. 20 This is a schematic diagram of the hand 100 when the introduction operation is completed, as viewed from the front. Fig.21 1 is a schematic plan view showing the positional relationship between the workpiece W1 and the hole H at the start of the introduction operation.

[0191] Specifically, the control device 130 operates the second motor 61. When the second motor 61 operates, the linear actuator 6, the rotary actuator 7, and the constraint actuator 93 operate. The linear actuator 6 moves the gripper 3 toward the front end side in the direction of the first reference axis X. The rotary actuator 7 rotates the gripper 3 clockwise in the forward direction of the gripper 3. The constraint actuator 93 opens the first retainer 91 and the second retainer 92 in the opening and closing direction Z.

[0192] Since the restrainer 9 changes from the restrained state to the released state, the movement of the connector 4 becomes possible. The connector 4 rotates around the first reference axis X while moving in the direction of the first reference axis X. Since the movement of the connector 4 becomes possible, the holder 3 moves together with the connector 4 in a state where it can be freely eccentric and tilted relative to the first reference axis X. As the connector 4 moves in the direction of the first reference axis X, the interval between the first retainer 91 and the second retainer 92 in the opening and closing direction Z expands. In other words, the movable range of the holder 3 expands.

[0193] At this time, if Fig.21As shown, the workpiece W1 rotates around the second reference axis α, that is, around the axis M, from the state of point contact with the opening edge of the hole H (see the two-dot chain arrow). As a result, the workpiece W1 rotates with point P as the fulcrum, and the workpiece W1 is guided to the opening edge of the hole H, so that the end of the workpiece W1 is embedded in the hole H (see the thick arrow). At that time, the workpiece W1 changes its posture in such a way that the axis M coincides with the axis N of the hole H. Since the constraint of the connector 4 by the restraint 9 is released, the gripper 3 can be freely eccentric and tilted relative to the first reference axis X. In other words, the workpiece W1 can change its posture while being gripped by the gripper 3 so that the axis M coincides with the axis N. In addition, the tilting connector 47 can transmit the rotation of the rotation axis 71 around the first reference axis X as a rotation around the second reference axis α to the gripper 3 while the second reference axis α of the gripper 3 is tilted relative to the first reference axis X. Therefore, the workpiece W1 changes its posture while rotating around the second reference axis α, that is, around the axis M, so that the axis M coincides with the axis N. Thus, the end of the workpiece W1 is smoothly inserted into the hole H. When the amount of advancement of the connector 4 in the direction of the first reference axis X after the start of the release operation and the introduction operation reaches a predetermined amount, the control device 130 completes the release operation and the introduction operation.

[0194] When the release action and import action are completed, Fig. 20 As shown, the second reference axis α of the gripper 3 is inclined relative to the first reference axis X. The second reference axis α and the axis M of the workpiece W1 and the axis N of the hole H are aligned in a straight line. The position and posture of the hand body 2 do not change from the start of the release action and the introduction action.

[0195] Next, in step S4 , the control device 130 causes the robot arm 120 and the hand 100 to perform an insertion operation in which the workpiece W1 is inserted into the hole H by operating the rotary actuator 7 in a state in which the first reference axis X and the axis N of the hole H are substantially parallel. Fig. 22 This is a schematic diagram of the hand 100 during the insertion operation, as viewed from the front. Fig.23 It is a schematic plan view showing the positional relationship between the workpiece W1 and the hole H during the insertion operation. Fig.24 This is a schematic diagram of the hand 100 when the insertion action is completed, as seen from the front.

[0196] Specifically, if Fig. 22As shown, the control device 130 changes the inclination of the hand body 2 by the robot arm 120 so that the first reference axis X is roughly parallel to the axis N of the hole H. Since the end of the workpiece W1 is inserted into the hole H, the gripper 3 is constrained in a state where the second reference axis α and the axis N of the hole H are arranged in a straight line. Due to the presence of the connector 4, the gripper 3 can be freely eccentric and tilted relative to the first reference axis X. As a result, the hand body 2 can be in a state where the first reference axis X is roughly parallel to and eccentric with respect to the second reference axis α and the axis N. It should be noted that, depending on the circumstances, the first reference axis X may also be arranged in a straight line with the second reference axis α and the axis N.

[0197] In this state, the control device 130 operates the linear actuator 6 and the rotary actuator 7. The tilting connector 47 can transmit the rotation of the rotary axis 71 around the first reference axis X to the gripper 3 as a rotation around the second reference axis α, while the second reference axis α of the gripper 3 is eccentric relative to the first reference axis X. As a result, the workpiece W1 rotates around the second reference axis α while moving forward in the direction of the second reference axis α. Since the second reference axis α and the axis M and the axis N are arranged on a straight line, Fig.23 As shown, the workpiece W1 is inserted into the hole H while rotating around the axis N in a state where the axis M coincides with the axis N. As a result, the workpiece W1 is inserted into the hole H smoothly.

[0198] It should be noted that when the linear actuator 6 and the rotary actuator 7 are operated, the restricting actuator 93 is also operated. Therefore, the interval between the first retainer 91 and the second retainer 92 in the opening and closing direction Z is also expanded.

[0199] like Fig.24 As shown, when the amount of advance of the connector 4 in the direction of the first reference axis X after the insertion action starts reaches a predetermined amount, the control device 130 completes the insertion action. It should be noted that when the workpiece W1 reaches the bottom of the hole H before the insertion action is completed, the first buffer 10 is deformed so that the movement of the gripper 3 and the workpiece W1 is absorbed. In addition, the insertion of the workpiece W1 can be achieved not only by the advancement of the connector 4, but also by the push of the hand 100 by the robot arm 120.

[0200] Then, the control device 130 operates the opening and closing actuator 8 to release the workpiece W1 gripped by the fingers 32. In this way, the control device 130 completes the insertion operation of the workpiece W1.

[0201] The insertion operation can be performed not only in a vertical hole but also in a horizontal hole. For example, the insertion operation is described in which the workpiece W1 is inserted into a hole H extending in a substantially horizontal direction by hand 100. The flow chart of the insertion operation is as shown in FIG. Fig.17shown.

[0202] The holding action in step S1 is the same as described above.

[0203] In step S2 , the control device 130 causes the robot arm 120 and the hand 100 to perform a contact operation. Fig.25 This is a schematic diagram of the hand 100 when the contact action with the hole H extending in the horizontal direction along the axis N is completed, as viewed from the front.

[0204] Specifically, if Fig.25 As shown, the control device 130 moves the robot arm 120 so that the workpiece W1 contacts the opening edge of the hole H while the first reference axis X and the second reference axis α are inclined relative to the axis N of the hole H. The restrainer 9 is in the restrained state.

[0205] Since the axis N of the hole H extends in the horizontal direction, the hand 100 is in a posture where the first reference axis X intersects with the vertical direction. When the hole H is in the vertical direction, the first reference axis X of the hand 100 is also inclined with respect to the vertical direction, but the angle formed by the vertical direction and the first reference axis X becomes larger than that at that time. At this time, the second retainer 92 is located at a lower position than the first retainer 91. The second retainer 92 supports most of the weight of the gripper 3 and the workpiece W1. It should be noted that the "position lower than the first retainer 91" does not need to be located directly below the first retainer 91 in the vertical direction. In other words, the second retainer 92 does not need to be arranged in the vertical direction with the first retainer 91, and the height position of the second retainer 92 only needs to be lower than the height position of the first retainer 91.

[0206] Next, in step S3 , the control device 130 causes the hand 100 to perform a release operation and an introduction operation. Fig.26 This is a schematic diagram of the hand 100 when the operation of introducing the hand 100 into the hole H extending in the horizontal direction is completed, as viewed from the front.

[0207] The restraining actuator 93 opens the first retainer 91 and the second retainer 92 in the opening and closing direction Z. In parallel, the linear actuator 6 moves the gripper 3 toward the front end in the first reference axis X direction, and the rotary actuator 7 rotates the gripper 3 clockwise in the forward direction of the gripper 3 .

[0208] By the restraint 3 being in the released state, the gripper 3 can be eccentric and tilted relative to the first reference axis X. Since the first reference axis X is tilted relative to the vertical direction, the gripper 3 and the workpiece W1's own weight make the gripper 3 eccentric and tilted relative to the first reference axis X. The first retainer 91 and / or the second retainer 92 are located radially outside the gripper 3 with the first reference axis X as the center. Therefore, the eccentric and tilted gripper 3 is supported by the first retainer 91 and / or the second retainer 92. In this example, since the second retainer 92 is located at a lower position than the first retainer 91, most of the weight of the gripper 3 and the workpiece W1 is supported by the second retainer 92. Since the restraint 9 has the transmission rubber 97, the first retainer 91 and the second retainer 92 are slightly opened in the opening and closing direction Z against the elastic force of the transmission rubber 97 due to the weight of the gripper 3 and the workpiece W1.

[0209] Here, the third contact surface 92a of the second holder 92 contacts the gripper 3 at one point (see Fig.14 ). That is, the second retainer 92 does not hinder the movement of the holder 3 along the third contact surface 92a. The connector 4 enables the holder 3, which can be eccentric and tilted, to move along the third contact surface 92a.

[0210] Next, the linear actuator 6, the rotary actuator 7, and the constraint actuator 93 operate, and the workpiece W1 rotates around the second reference axis α, that is, around the axis M, while changing its posture so that the axis M is consistent with the axis N. The first retainer 91 and the second retainer 92 slowly open in the opening and closing direction Z. However, since the restraint 9 has a transmission rubber 97, when the gripper 3 contacts the first retainer 91 or the second retainer 92, the first retainer 91 and the second retainer 92 are elastically displaced in the opening and closing direction Z so as not to hinder the movement of the gripper 3. In this way, the end of the workpiece W1 is smoothly inserted into the hole H.

[0211] Then, in step S4 , the control device 130 causes the robot arm 120 and the hand 100 to perform an insertion operation. Fig. 27 This is a schematic diagram of the hand 100 when performing an insertion operation into the hole H extending in the horizontal direction, as viewed from the front.

[0212] The robot arm 120 changes the inclination of the hand body 2 so that the first reference axis X is roughly parallel to the axis N of the hole H. The hand body 2 can be in a state where the first reference axis X is roughly parallel to the second reference axis α and the axis N and is eccentric. In this state, the linear actuator 6 and the rotary actuator 7 cause the connector 4 to rotate around the first reference axis X while advancing in the direction of the first reference axis X. The eccentric connector 41 transmits the rotation of the rotation axis 71 around the first reference axis X to the holder 3 as a rotation around the second reference axis α in a state where the second reference axis α of the holder 3 is eccentric to the first reference axis X. As a result, the workpiece W1 rotates around the second reference axis α while advancing in the direction of the second reference axis α. Since the second reference axis α and the axis M and the axis N are arranged on a straight line, the workpiece W1 is inserted into the hole H while rotating around the axis N in a state where the axis M coincides with the axis N. As a result, the workpiece W1 is smoothly inserted into the hole H.

[0213] It should be noted that when the linear actuator 6 and the rotary actuator 7 are operated, the restricting actuator 93 is also operated. Therefore, the interval between the first retainer 91 and the second retainer 92 in the opening and closing direction Z is also expanded.

[0214] When the insertion operation is completed, the control device 130 operates the opening and closing actuator 8 to release the workpiece W1 gripped by the fingers 32. In this way, the control device 130 completes the insertion operation of the workpiece W1.

[0215] Thus, in the insertion operation, the workpiece W1 is inserted into the hole H by rotating the workpiece W1 about the second reference axis α from a state where the second reference axis α is tilted relative to the axis N of the hole H and the workpiece W1 is in point contact or line contact with the opening edge of the hole H (hereinafter, such insertion is referred to as "rotational tilt insertion". The rotational tilt insertion of the workpiece W1 can be easily achieved by using the hand 100 for the insertion operation. That is, the rotation actuator 7 is operated from a state where the second reference axis α is tilted relative to the axis N of the hole H and the workpiece W1 is in point contact or line contact with the opening edge of the hole H, that is, the rotation axis 71 is rotated about the first reference axis X. The workpiece W1 is inserted into the hole H by rotating the workpiece W1 so that the axis M coincides with the axis N, and the holder 3 is tilted relative to the first reference axis X to make this possible. The connector 4 can transmit the rotation of the rotation axis 71 around the first reference axis X to the holder 3 as a rotation around the second reference axis α even when the holder 3 is tilted relative to the first reference axis X. Since the workpiece W1 is inserted into the hole H while rotating around the second reference axis α, the insertion of the workpiece W1 into the hole H is smoother. By using the hand 100 for the insertion operation, the rotational tilting insertion of the workpiece W1 can be easily achieved regardless of the direction of the axis N of the hole H.

[0216] According to the hand 100 constructed in this way, since the connector 4 flexibly supports the gripper 3, specifically, supports it eccentrically and tiltably with respect to the first reference axis X, even if the position of the workpiece gripped by the gripper 3 deviates from the desired position, the connector 4 can absorb the position deviation and arrange the workpiece at the desired position. Therefore, the positioning accuracy required for the hand 100 and the robot arm 120 can be reduced.

[0217] The hand 100 achieves such flexible support of the gripper 3 not by the shaking between the parts of the hand 100 or the rigidity of the parts themselves, but by the eccentric connector 41 and the inclined connector 47. When the gripper 3 is supported flexibly by the shaking between the parts, it is difficult to design and manage because the flexibility of the support is determined by the trend. On the other hand, according to the eccentric connector 41 and the inclined connector 47, the flexibility of the support of the gripper 3 and the movable area can be appropriately designed and managed.

[0218] In addition, the connector 4 does not flexibly support the entire hand 100 including the hand body 2, but flexibly supports the gripper 3. That is, the weight of the component supported by the connector 4 is reduced compared to when the connector 4 also supports the hand body 2. As a result, the inertia (i.e., moment of inertia) of the component supported by the connector 4 is reduced, and the responsiveness when the gripper 3 is tilted or eccentric relative to the first reference axis X is improved.

[0219] Furthermore, in order to realize low inertia of the gripper 3, an opening and closing actuator 8 for opening and closing the gripper 3 is arranged on the hand body 2. The connector 4 has a power transmitter 5, which transmits the driving force of the opening and closing actuator 8 to the gripper 3 in a state where the second reference axis α is eccentric or tilted relative to the first reference axis X. Specifically, the power transmitter 5 has a first joint 51, and the first joint 51 includes a first ball coupling 52 and a second ball coupling 53. Even in a structure in which the opening and closing actuator 8 is arranged on the hand body 2 and the gripper 3 is supported eccentrically or tiltably by the connector 4, the gripper 3 can be opened and closed by the driving force of the opening and closing actuator 8 by providing such a power transmitter 5.

[0220] Furthermore, the gripper 3 is configured to rotate around the second reference axis α. Thus, the work of inserting the workpiece into the hole can be performed more easily by using the hand 100. That is, when the workpiece is inserted into the hole while rotating, the workpiece can be inserted into the hole more smoothly than when the workpiece is simply inserted into the hole without rotating the workpiece.

[0221] Furthermore, in order to realize low inertia of the gripper 3, a rotary actuator 7 for rotating the gripper 3 around the second reference axis α is arranged on the hand body 2. The connector 4 transmits the driving force of the rotary actuator 7 to the gripper 3 in a state where the second reference axis α is eccentric or tilted relative to the first reference axis X. As a result, even in a structure where the rotary actuator 7 is arranged on the hand body 2 and the gripper 3 is supported by the connector 4 in a tiltable or eccentric manner, the gripper 3 can be rotated by the driving force of the rotary actuator 7.

[0222] The hand 100 moves the connector 4 in the direction of the first reference axis X via the linear actuator 6. Therefore, the workpiece W1 can be inserted into the hole H while changing the inclination of the workpiece W1 without moving the hand body 2, that is, without moving the robot arm 120.

[0223] Furthermore, since the linear actuator 6 and the rotary actuator 7 share the second motor 61 as a driving source, the linear actuator 6 and the rotary actuator 7 operate simultaneously, so that the rotary shaft 71 can be easily rotated around the first reference axis X while moving forward in the direction of the first reference axis X.

[0224] Furthermore, since the hand 100 includes the restraint 9, the gripper 3 is not always eccentric or tiltable relative to the first reference axis X, but can be made not eccentric or tiltable by the restraint 9. The position of the gripper 3 can be stabilized by restraining the connector 4 with the restraint 9. For example, by restraining the connector 4 with the restraint 9 when the workpiece W1 is brought into point contact with the opening edge of the hole H, the position of the workpiece W1 can be stabilized, and the position adjustment of the workpiece W1 can be performed with good accuracy.

[0225] Furthermore, when the connector 4 is constrained by the constrainer 9, the second reference axis α is aligned with the first reference axis X. Therefore, in the constrained state by the constrainer 9, the position of the hand 100 can be controlled with reference to the first reference axis X of the hand body 2, thereby inevitably controlling the position of the second reference axis α of the gripper 3. For example, it is easy to control the position of the robot arm 120 and the hand 100 when performing a contact action.

[0226] In addition, the restraint 9 switches the restraint state of the connector 4 brought about by the contact with the holder 3 and the release state of the connector 4 brought about by the separation from the holder 3 through the opening and closing action. Therefore, the restraint state and the release state of the connector 4 can be switched immediately. For example, as another structure, a structure that restrains the movement of the connector 4 by making the holder 3 and other components fit in the direction of the first reference axis X can be conceived. However, in order to release the restraint state, it is necessary to completely pull out the other side of the holder 3 and other components from one side, and it takes time to release the restraint state. In addition, when the force acts in a direction intersecting the pulling direction during the action of pulling out the other side from the holder 3 and other components, the holder 3 and other components are stuck, and there is a fear that the pulling action cannot be performed smoothly. In contrast, since the restraint 9 separates from the holder 3 through the opening and closing action, it can immediately separate from the holder 3, and as a result, the restraint of the connector 4 can be immediately released. Furthermore, since the distance between the gripper 3 and the restraint 9 increases due to the separation of the restraint 9 from the gripper 3 during the release from the restraint state, the gripper 3 and the restraint 9 are less likely to get stuck. Furthermore, the separation of the restraint 9 from the gripper 3 through the opening and closing action is not only a release from the restraint state, but also an action to eliminate the jam with the gripper 3. In other words, even if the gripper 3 and the restraint 9 get stuck, the restraint 9 can easily eliminate the jam.

[0227] Furthermore, the restraint 9 has a transmission rubber 97. Specifically, the restraint transmission 94 that transmits the driving force of the second motor 61 to displace the first retainer 91 and the second retainer 92 includes the transmission rubber 97. More specifically, in the restraint transmission 94, the first transmission 95 and the second transmission 96 are elastically connected by the transmission rubber 97. Since the restraint 9 elastically holds the gripper 3, the gripper 3 can be displaced in response to the elastic deformation of the transmission rubber 97 even in the state of being held by the restraint 9. As a result, the hand 100 can absorb the position deviation of the gripper 3 within the range of the elastic deformation of the transmission rubber 97 even in the restrained state of the restraint 9.

[0228] Furthermore, since the gripper 3 can be eccentric or tilted, the gripper 3 sometimes contacts the first retainer 91 and / or the second retainer 92 when the restrainer 9 is released. In particular, when the hand 100 is in a posture such that the first reference axis X intersects with the vertical direction, the gripper 3 is more likely to be eccentric or tilted due to its own weight and the load of the workpiece W1 when the restrainer 9 is released. Depending on the inclination angle of the first reference axis X and the opening of the first retainer 91 and the second retainer 92, the gripper 3 sometimes contacts the first retainer 91 and / or the second retainer 92 and is supported by the first retainer 91 and / or the second retainer 92. At this time, since the first retainer 91 and / or the second retainer 92 can be elastically displaced in the opening and closing direction Z, it can be elastically supported without hindering the movement of the gripper 3. As a result, smooth movement of the gripper 3 can be achieved.

[0229] Furthermore, since the first retainer 91 contacts the holder 3 at least at two locations in the contact state and the second retainer 92 contacts the holder 3 at one location in the contact state, the position accuracy of the holder 3 can be improved.

[0230] In addition, when the gripper 3 is relatively displaced in the released state of the restrainer 9, the gripper 3 may contact the first retainer 91 and / or the second retainer 92. When the hand 100 is used in a posture in which the second retainer 92 is located lower than the first retainer 91, the gripper 3 contacts the second retainer 92 located relatively lower and may be supported by the second retainer 92. At this time, since the second retainer 92 supports the gripper 3 at one place, the gripper 3 can move along the shape of the second retainer 92. Assume that when the gripper 3 is supported by the first retainer 91, since the first retainer 91 supports the gripper 3 at two places, the gripper 3 is supported in a non-displaceable manner. At that time, the function of the connector 4 that can change the position of the gripper 3 is not fully exerted. That is, the second retainer 92 can support the weight of the gripper 3 in a state where the function of the connector 4 is exerted by supporting the gripper 3 only at one place.

[0231] Furthermore, since the hand 100 includes the first shock absorber 10, when an excessive force in the first reference axis X direction acts on the gripper 3, such force can be absorbed by the first shock absorber 10. As a result, the position accuracy of the gripper 3 in the first reference axis X direction can be relaxed.

[0232] In addition, the restraint 9 elastically supports the first retainer 91 and the second retainer 92 in the direction of the first reference axis X through the second buffer 98. Since the first retainer 91 and the second retainer 92 can be elastically displaced in the direction of the first reference axis X, the gripper 3 can be relatively moved in the direction of the first reference axis X relative to the hand body 2 even in the restrained state by the restraint 9. In this way, the gripper 9 can hold the gripper 3 elastically displaceable in the direction of the first reference axis X, so that the first buffer 10 that absorbs the force in the direction of the first reference axis X acting on the gripper 3 can effectively function even in the restrained state.

[0233] Furthermore, the driving source of the constraint actuator 93 is the second motor 61, which is common to the driving source of the linear actuator 6. Furthermore, the driving source of the constraint actuator 93 is common to the driving source of the rotary actuator 7. Therefore, the driving source of the hand 100 can be reduced, and the number of parts and costs can be reduced. Furthermore, since the driving source is common, the linear actuator 6, the rotary actuator 7 and the constraint actuator 93 are linked. Therefore, the release action of the constraint 9 and the introduction action of the workpiece W1 can be performed in parallel. As a result, the time from the completion of the contact of the workpiece W1 with the opening edge of the hole H to the partial insertion of the workpiece W1 into the hole H is shortened, thereby shortening the time required for the insertion operation.

[0234] 《Other Implementation Methods》

[0235] As described above, the embodiments are described as examples of the technology disclosed in this application. However, the technology disclosed in the present invention is not limited thereto, and can also be applied to embodiments that have been appropriately changed, replaced, added, omitted, etc. Furthermore, the various constituent elements described in the embodiments can also be combined as new embodiments. Furthermore, the constituent elements recorded in the drawings and detailed descriptions include not only the constituent elements necessary to solve the problem, but also constituent elements that are not necessary to solve the problem in order to exemplify the technology. Therefore, it should not be immediately assumed that those non-essential constituent elements are necessary just because they are recorded in the drawings and detailed descriptions.

[0236] For example, the hand 100 may not be connected to the robot arm 120. The hand 100 may not be applied to the robot 110 but may be applied to a dedicated machine or the like.

[0237] The operation performed by the hand 100 is not limited to the insertion operation. The operation performed by the hand 100 may be an operation of simply picking up a component or an operation of placing a component at a predetermined location.

[0238] The insertion operation is not only a simple insertion of the workpiece W into the hole H, but also may be a press-fitting of the workpiece W1 into the hole H or a meshing of the workpiece W1 into the threaded hole. Furthermore, the insertion operation is not limited to rotational and tilted insertion. That is, when inserting the workpiece W1 into the hole H, the workpiece W1 may be inserted into the hole H in a state where the second reference axis α and the axis N of the hole H are arranged substantially parallel or in a straight line. Alternatively, when inserting the workpiece W1 into the hole H, the workpiece W1 may be inserted into the hole H in a state where the workpiece W1 is in line contact with the opening edge of the hole H or in contact with multiple points.

[0239] In the above insertion operation, after the robot system 1000 has introduced the workpiece W1 into the hole H by rotational tilt insertion, it further performs the insertion operation in a state where the first reference axis X is substantially parallel to the axis N of the hole H, but the present invention is not limited thereto. For example, after the introduction operation, the workpiece W1 may be continuously inserted into the hole H in a state where the first reference axis X is tilted relative to the axis N of the hole H.

[0240] The hand 100 may omit at least one of the linear actuator 6 and the rotary actuator 7. For example, the entire hand 100 may be moved linearly in the direction of the first reference axis X, or rotated around the first reference axis X, by the robot arm 120.

[0241] The connector 4 only needs to eccentrically or tilt the second reference axis α of the holder 3 with respect to the first reference axis X. In other words, the connector 4 only needs to be able to have either eccentricity or tilt of the holder 3 .

[0242] The mechanism for eccentricating the second reference axis α of the gripper 3 relative to the first reference axis X is not limited to the structure of the eccentric connector 41. For example, the eccentric connector 41 may include only one of the second joint 45, the eccentric body 42, the rolling body 43, and the first disk 71c.

[0243] The second joint 45 is not limited to a cross slider joint. The second joint 45 can be any joint that transmits rotation between two eccentric shafts. For example, the second joint 45 can also be a Schmidt joint or a pin joint, wherein a pin of a disk installed on one shaft is embedded in a circular hole of a disk installed on another shaft to transmit rotation.

[0244] The third joint 48 is not limited to a universal joint. The third joint 48 can be any joint that transmits rotation between two inclined axes (ie, two axes with an angle). For example, the third joint 48 can also be a flexible joint, a torque coil, or a ball joint.

[0245] The action mechanism 33 of the gripper 3 is not limited to the link mechanism. The action mechanism 33 can be any mechanism that is driven by the rotation of the opening and closing shaft 84 to open and close the finger 32. For example, the action mechanism 33 can also be a mechanism that opens and closes the finger 32 using a slider or a rack and pinion method.

[0246] The first joint 51 is not limited to the first ball coupling 52 and the second ball coupling 53. The first joint 51 can be any joint that transmits rotation between two eccentric or inclined shafts. For example, the first joint 51 can also be one or more universal joints, flexible joints, torque coils, ball joints, cross slider joints, Schmidt joints, or pin joints.

[0247] The restraint 9 is not limited to the above structure. The restraint 9 can adopt any structure as long as it switches the restraint state and the release state through the opening and closing action. For example, the restraint 9 can also include one or more other retainers in addition to the first retainer 91 and the second retainer 92. For example, the restraint 9 can also have three retainers that perform the opening and closing action.

[0248] The restraint 9 may also hold the holder 3 in the restrained state by contacting a portion other than the second tube 34b of the holder 3, for example, by contacting the first tube 34a.

[0249] Furthermore, the first retainer 91 and the second retainer 92 are closed to contact the holder 3 from the outside, but the present invention is not limited thereto. The first retainer 91 and the second retainer 92 may be disposed inside the holder 3 and open to contact the holder 3 from the inside.

[0250] The structure of the constraint actuator 93 is not limited to the above structure. The driving source of the constraint actuator 93 may also be separated from the driving source of the linear actuator 6 or the rotary actuator 7. That is, the constraint actuator 93 may also be independent of the linear actuator 6 or the rotary actuator 7 to move the first retainer 91 and the second retainer 92. The constraint transmission 94 may not be a structure including the first transmission 95, the second transmission 96 and the transmission rubber 97. For example, the constraint transmission 94 may also be a linear guide or a feed screw mechanism, which transmits the driving force of the motor to the first retainer 91 and the second retainer 92, and guides the first retainer 91 and the second retainer 92 in the opening and closing direction Z. At that time, the part connecting the linear guide or the feed screw mechanism and the first retainer 91 and the second retainer 92 may include a first elastic component.

[0251] The first elastic component that elastically holds the holder 3 in the constrained state is not limited to the transmission rubber 97. For example, the first elastic component may be a spring instead of rubber. For example, a coil spring may be arranged in the coupling hole 96h as the first elastic component instead of the transmission rubber 97. In addition, the configuration of the first elastic component is not limited to the configuration of the above-mentioned transmission rubber 97. For example, the first retainer 91 and the third connecting rod 96c may be elastically connected in the opening and closing direction Z via the first elastic component. Similarly, the second retainer 92 and the sixth connecting rod 96f may be elastically connected in the opening and closing direction Z via the first elastic component. Alternatively, the first retainer 91 and the second retainer 92 may be formed of an elastomer such as silicone rubber and have elasticity in the opening and closing direction Z.

[0252] The second buffer 98 is provided between the second conveyor 96 and the first and second holders 91 and 92 , but is not limited thereto.

[0253] The flowchart is just an example. The steps in the flowchart may be appropriately changed, replaced, added, omitted, etc. Also, the order of the steps in the flowchart may be changed, or serial processing may be performed in parallel. For example, step S3 and step S4 may be performed continuously, without a boundary between the import action and the insert action.

[0254] The functions implemented by the components described in this specification may also be implemented in a circuit or processing circuitry that includes a general-purpose processor, a special-purpose processor, an integrated circuit, an ASIC (Application Specific Integrated Circuits), a CPU (a Central Processing Unit), a conventional circuit, and / or a combination thereof that is programmed to implement the described functions. The processor includes transistors and other circuits and is considered a circuit or processing circuit. The processor may also be a programmable processor that executes a program stored in a memory.

[0255] In this specification, a circuit, unit or device is hardware programmed or executed to implement the described functions. The hardware may also be various hardware disclosed in this specification or various hardware that is well known as programmed or executed hardware to implement the described functions.

[0256] When the hardware is a processor of a type regarded as a circuit, the circuit, device or unit is a combination of hardware and software used to constitute the hardware and / or processor.

[0257] The technology of the present invention is summarized as follows.

[0258] [1] The hand 100 includes a hand body 2, a gripper 3, a connector 4 and a restraint 9, wherein the gripper 3 grips a workpiece, the connector 4 connects the gripper 3 to the hand body 2 in a manner that can change the relative position of the gripper 3 relative to the hand body 2, the restraint 9 restrains the movement of the connector 4, and the restraint 9 switches between a restraint state and a release state by an opening and closing action. In the restraint state, the movement of the connector 4 is restrained by contacting the gripper 3, and in the release state, the movement of the connector 4 is released by moving away from the gripper 3.

[0259] According to this structure, the hand 100 grasps the workpiece by means of the gripper 3 whose relative position with respect to the hand body 2 can be changed. The hand 100 can absorb the position deviation of the gripper 3 by means of the connector 4. Therefore, even if the position accuracy of the gripper 3 is not too high, the work performed by the gripper 3 can be properly performed. Furthermore, it is not the position of the entire hand 100 including the hand body 2 that is changed, but it is the relative position of the gripper 3 that can be changed. In this way, the moment of inertia of the component supported by the connector 4 can be reduced. As a result, the responsiveness when the relative position of the gripper 3 is changed can be improved.

[0260] In addition, since the restraint 9 switches the restraint state of the connector 4 and the release state of the connector 4 through the opening and closing action, the restraint state and the release state can be switched immediately. Furthermore, since the distance between the gripper 3 and the restraint 9 is increased by the restraint 9 moving away from the gripper 3 during the release from the restraint state, it is difficult for the gripper 3 and the restraint 9 to get stuck. Furthermore, the restraint 9 moving away from the gripper 3 through the opening and closing action is not only a release from the restraint state, but also an action to eliminate the jam with the gripper 3. Assuming that even if the gripper 3 and the restraint 9 get stuck, the restraint 9 can easily eliminate the jam.

[0261] [2] In the hand 100 described in [1], the restraint 9 has a transmission rubber 97 (first elastic member) and restrains the movement of the connector 4 by elastically holding the holder 3 in the restrained state.

[0262] According to this structure, the gripper 3 can be displaced in response to the elastic deformation of the transmission rubber 97 even when it is held by the restraint 9. That is, the connector 4 can make the gripper 3 relatively displaced with respect to the hand body 2 within the range of the elastic deformation of the transmission rubber 97 even when it is restrained by the restraint 9. As a result, the hand 100 can absorb the position deviation of the gripper 3 within the range of the elastic deformation of the transmission rubber 97 even when it is restrained by the restraint 9. Therefore, even if the position accuracy of the gripper 3 is not too high, the operation performed by the gripper 3 can be properly performed.

[0263] [3] In the hand 100 described in [1] or [2], the restraint 9 has a first retainer 91 and a second retainer 92 and a restraint actuator 93, the first retainer 91 and the second retainer 92 contact the gripper 3 in the restrained state, the restraint actuator 93 causes the first retainer 91 and the second retainer 92 to open and close, the restraint actuator 93 has a second motor 61 (restraint drive source) and a restraint transmission 94, the second motor 61 generates a driving force, the restraint transmission 94 connects the second motor 61 and the first retainer 91 and the second retainer 92, and transmits the driving force of the second motor 61 to the first retainer 91 and the second retainer 92, and the transmission rubber 97 is contained in the restraint transmission 94.

[0264] According to this structure, the constraint transmission 94 that transmits the driving force of the second motor 61 to displace the first retainer 91 and the second retainer 92 includes a transmission rubber 97. When the transmission rubber 97 is elastically deformed, the state of the constraint transmission 94 changes, and as a result, the positions of the first retainer 91 and the second retainer 92 may change. In other words, the elastic holding of the holder 3 by the first retainer 91 and the second retainer 92 can be achieved by elastically changing the state of the constraint transmission 94.

[0265] [4] In the hand 100 described in any one of [1] to [3], the constraint transmitter 94 has a first transmitter 95 and a second transmitter 96, the first transmitter 95 is input with driving force from the second motor 61, the second transmitter 96 transmits the driving force to the first retainer 91 and the second retainer 92, and the transmission rubber 97 elastically connects the first transmitter 95 and the second transmitter 96.

[0266] According to this structure, the transmission rubber 97 elastically connects the first transmission 95 and the second transmission 96 included in the constraint transmission 94. That is, the transmission rubber 97 transmits the driving force of the second motor 61 from the first transmission 95 to the second transmission 96. In addition, the external force acting on the first retainer 91 and the second retainer 92 is transmitted to the transmission rubber 97 via the second transmission 96. As a result, the transmission rubber 97 is elastically deformed, and accordingly, the first retainer 91 and the second retainer 92 can be elastically displaced.

[0267] [5] In the hand 100 described in any one of items [1] to [4], the restraint 9 has a first retainer 91 and a second retainer 92 and a restraint actuator 93, the first retainer 91 and the second retainer 92 contact the gripper 3 in the restrained state, the restraint actuator 93 causes the first retainer 91 and the second retainer 92 to perform an opening and closing action, the first retainer 91 and the second retainer 92 switch to a contact state with the gripper 3 and a separation state from the gripper 3 by performing an opening and closing action, the first retainer 91 contacts the gripper 3 at least at two locations in the contact state, and the second retainer 92 contacts the gripper 3 at one location in the contact state.

[0268] According to this structure, since the first holder 91 and the second holder 92 contact and hold the holder 3 at least at three locations, the position accuracy of the holder 3 can be improved.

[0269] [6] In the hand 100 described in any one of items [1] to [5], the gripper 3 is configured to move straight in the direction of a predetermined first reference axis X relative to the hand body 2, and the first retainer 91 and the second retainer 92 are opened and closed in a direction intersecting the direction of the first reference axis X. When the hand 100 is in a posture where the first reference axis X intersects the vertical direction, the second retainer 92 is located at a lower position than the first retainer 91.

[0270] According to this structure, when the restraint 9 switches from the restrained state to the released state, the gripper 3 can be relatively displaced by the connector 4. When the distance between the first retainer 91 and the second retainer 92 and the gripper 3 is not too far in the released state of the restraint 9, the gripper 3 is relatively displaced and may contact the first retainer 91 and the second retainer 92. Since the second retainer 92 is located at a lower position than the first retainer 91, the second retainer 92 can support the gripper 3 that is displaced due to its own weight. Since the second retainer 92 supports the gripper 3 at one place, the gripper 3 can move along the shape of the second retainer 92. That is, the second retainer 92 can support the weight of the gripper 3 in a state where the connector 4 can function.

[0271] That is to say, when the restraint device 9 is in a restrained state, the holder 3 can be held with a higher position accuracy by the first retainer 91 and the second retainer 92, and when the restraint device 9 is in a released state, the holder 3 can be supported by the second retainer 92 in a relatively displaceable state.

[0272] [7] In the hand 100 described in any one of [1] to [6], the gripper 3 is configured to move straight in the direction of a predetermined first reference axis X relative to the hand body 2, the restraint 9 has a first retainer 91 and a second retainer 92, a restraint actuator 93 and a second buffer 98 (buffer), the first retainer 91 and the second retainer 92 contact the gripper 3 in the restrained state, the restraint actuator 93 causes the first retainer 91 and the second retainer 92 to open and close, the second buffer 98 (buffer) elastically supports the first retainer 91 and the second retainer 92 in the direction of the first reference axis X, the second buffer 98 has a guide 98a and a second spring 98b (second elastic component), the guide 98a guides the first retainer 91 and the second retainer 92 displaceably in the direction of the first reference axis X, and the second spring 98b (second elastic component) elastically supports the first retainer 91 and the second retainer 92 along the guide 98a.

[0273] According to this structure, the first retainer 91 and the second retainer 92 perform an opening and closing action by the restraining actuator 93, and on the other hand, are elastically supported in the direction of the first reference axis X by the second buffer 98. Therefore, even in the restrained state by the restraining device 9, the gripper 3 can move relative to the hand body 2 in the direction of the first reference axis X together with the first retainer 91 and the second retainer 92. For example, in the structure including the first buffer 10, even in the restrained state of the restraining device 9, the first buffer 10 can effectively function, and the first buffer 10 absorbs the force in the direction of the first reference axis X that the hand 100 acts on the gripper 3.

[0274] [8] In the hand 100 described in any one of [1] to [7], it also includes a straight-moving actuator 6, which causes the gripper 3 to move straight relative to the hand body in the direction of a predetermined first reference axis X, the restraint 9 has a first retainer 91 and a second retainer 92 and a restraint actuator 93, the first retainer 91 and the second retainer 92 contact the gripper 3 in the restrained state, the restraint actuator 93 causes the first retainer 91 and the second retainer 92 to open and close, and the straight-moving actuator 6 has a second motor 61 (straight-moving drive source) and a straight-moving transmission. 67, the second motor 61 (straight driving source) generates driving force, the straight transmission 67 transmits the driving force of the second motor 61 to the holder 3, the constraint actuator 93 has a second motor 61 and a constraint transmission 94, the second motor 61 generates driving force, the constraint transmission 94 connects the second motor 61 and the first retainer 91 and the second retainer 92, and transmits the driving force of the second motor 61 to the first retainer 91 and the second retainer 92, the second motor 61 of the straight actuator 6 and the second motor 61 of the constraint actuator 93 are common.

[0275] According to this configuration, the linear actuator 6 and the restricting actuator 93 can be operated by the common second motor 61. By reducing the number of driving sources of the hand 100, the number of components and the cost of the hand 100 can be reduced.

[0276] [9] In the hand 100 described in any one of [1] to [8], a predetermined first reference axis X is specified in the hand body 2, and a predetermined second reference axis α is specified in the gripper 3, and the connector 4 includes at least one of an eccentric connector 41 and an inclined connector 47, the eccentric connector 41 supports the gripper 3 in a manner that the second reference axis α can be eccentric relative to the first reference axis X, and the inclined connector 47 supports the gripper 3 in a manner that the second reference axis α can be inclined relative to the first reference axis X.

[0277] According to this structure, the hand 100 holds the workpiece by means of the gripper 3 which is eccentric or tiltable relative to the first reference axis X by means of the second reference axis α. The position deviation of the gripper 3 can be absorbed by the eccentric connector 41 or the tilted connector 47. Therefore, even if the position accuracy of the gripper 3 is not too high, the work performed by the gripper 3 can be properly performed. In addition, the connector 4 does not support the entire hand 100 including the hand body 2 eccentrically or tiltably, but supports the gripper 3 eccentrically or tiltably. In this way, the moment of inertia of the component supported by the connector 4 can be reduced. As a result, the responsiveness when the gripper 3 is tilted or eccentric relative to the first reference axis X can be improved.

[0278]

[10] In the hand 100 described in any one of [1] to [9], the connector 4 includes both an eccentric connector 41 and an inclined connector 47 .

[0279] According to this structure, the connector 4 can absorb both the eccentricity and the deflection angle of the second reference axis α with respect to the first reference axis X. That is, the connector 4 absorbs the positional deviation of the holder 3 more flexibly.

[0280]

[11] In the hand 100 described in any one of [1] to

[10] , the restraint 9 restrains the movement of the connector in a state where the first reference axis and the second reference axis are aligned on a straight line.

[0281] According to this structure, in the restrained state by the restraint device 9, the position of the second reference axis α of the gripper 3 can be necessarily controlled by controlling the position of the hand 100 based on the first reference axis X of the hand body 2.

[0282]

[12] In the hand 100 described in any one of [1] to

[11] , the hand body 2 has an opening and closing actuator 8, which opens and closes the gripper 3, and the connector 4 has a power transmitter 5, which transmits the driving force of the opening and closing actuator 8 to the gripper 3. The power transmitter 5 transmits the driving force of the opening and closing actuator 8 to the gripper 3 when the second reference axis α is eccentric or inclined relative to the first reference axis X.

[0283] According to this structure, the opening and closing actuator 8 for opening and closing the gripper 3 can be provided in the hand body 2, thereby promoting the weight reduction of the gripper 3. Furthermore, even in a structure in which the opening and closing actuator 8 is provided in the hand body 2 and the connector 4 supports the gripper 3 eccentrically or tiltably with respect to the first reference axis X, the driving force of the opening and closing actuator 8 can be appropriately transmitted to the gripper 3 via the power transmission device 5. In other words, by providing the power transmission device 5, it is possible to take into account both the driving of the gripper 3 by the opening and closing actuator 8 disposed in the hand body 2 and the eccentric or tiltable support of the gripper 3 by the connector 4.

[0284]

[13] In the hand 100 described in any one of items [1] to

[12] , the opening and closing actuator 8 includes a first motor 81 (opening and closing drive source) and an opening and closing shaft 84, wherein the first motor 81 (opening and closing drive source) generates a driving force, and the opening and closing shaft 84 extends around the first reference axis X as the axis and is rotated around the first reference axis X by the driving force of the first motor 81, the power transmitter 5 includes a first joint 51, and the first joint 51 connects the opening and closing shaft 84 and the holder 3, the connector 4 includes a tilting connector 47, and the first joint 51 transmits the rotation of the opening and closing shaft 84 to the holder 3 when the second reference axis α is tilted relative to the first reference axis X, and the holder 3 has a base 31 and a plurality of fingers 32, and the plurality of fingers are supported by the base 31, and the opening and closing action is performed by the rotation of the opening and closing shaft 84.

[0285] According to this structure, the opening and closing actuator 8 rotates the opening and closing shaft 84 around the first reference axis X. The opening and closing shaft 84 is connected to the holder 3 via the first joint 51 of the power transmission device 5. In this way, even if the second reference axis α is inclined relative to the first reference axis X, the rotation of the opening and closing shaft 84 around the first reference axis X can be transmitted to the holder 3. As a result, the plurality of fingers 32 can be opened and closed appropriately.

[0286]

[14] In the hand 100 described in any one of [1] to

[13] , the connector 4 further includes an eccentric connector 41, and the first joint 51 transmits the rotation of the opening and closing shaft 84 to the holder 3 when the second reference axis α is eccentric relative to the first reference axis X.

[0287] According to this structure, the connector 4 includes both the eccentric connector 41 and the tilt connector 47. The first joint 51 can transmit the rotation of the opening and closing shaft 84 to the holder 3 regardless of whether the second reference axis α is eccentric with respect to the first reference axis X or tilted. As a result, even when the holder 3 is eccentric with respect to the first reference axis X and tilted, the plurality of fingers 32 can be opened and closed appropriately.

[0288]

[15] The robot system 1000 includes the hand 100, the robot arm 120 and the control device 130 recorded in any one of [1] to

[14] , wherein the robot arm 120 is connected to the hand 100, and the control device 130 controls the robot arm 120 and the hand 100, and the control device 130 enables the robot arm 120 and the hand 100 to perform an insertion operation, in which the workpiece W1 held by the hand 100 is inserted into a predetermined hole H.

[0289] According to this structure, the hand 100 performs the insertion operation of inserting the workpiece W1 into the hole H. The gripper 3 of the hand 100 is supported by the connector 4 in a manner that the relative position with respect to the hand body 2 can be changed. Therefore, even if the position adjustment of the workpiece W1 with respect to the hole H is not strictly performed, the gripper 3 can be appropriately displaced by the connector 4, and the insertion operation of the workpiece W1 into the hole H can be smoothly performed.

[0290]

[16] In the robot system described in

[15] , a predetermined first reference axis X is specified in the hand body 2, and a predetermined second reference axis α is specified in the gripper 3. The connector includes at least one of an eccentric connector 41 and an inclined connector 47. The eccentric connector 41 supports the gripper 3 in a manner that the second reference axis α can be eccentric relative to the first reference axis X, and the inclined connector 47 supports the gripper 3 in a manner that the second reference axis α can be tilted relative to the first reference axis X. The control device 130 causes the workpiece W1 gripped by the gripper 3 to be inserted into the hole H in a state where the second reference axis α is eccentric or tilted relative to the axis N of the hole H.

[0291] According to this structure, the workpiece W1 is inserted into the hole H from a state where the workpiece W1 is somewhat offset from the hole H. At that time, the workpiece W1 is guided to the opening edge of the hole H and is attempted to be inserted into the hole H. At this time, since the holder 3 can be eccentric or tilted relative to the first reference axis X, the workpiece W1 can freely change its posture and be smoothly inserted into the hole H.

[0292]

[17] In the robot system 1000 described in

[15] or

[16] , the hand body 2 has a rotary actuator 7, which is connected to the connector 4 and causes the gripper 3 to rotate around the second reference axis α. The connector 4 includes a tilt connector 47, and transmits the driving force of the rotary actuator 7 to the gripper 3 when the second reference axis α is tilted relative to the first reference axis X. The control device 130 causes the robot arm 120 to move in such a way that the workpiece W1 held by the gripper 3 is in point contact with the opening edge of the hole H when the tilt connector 47 is constrained by the constraint 9 and the second reference axis α is tilted relative to the axis N of the hole H. The workpiece W1 is inserted into the hole H by moving the rotary actuator 7 when the constraint of the tilt connector 47 by the constraint 9 is released.

[0293] According to this structure, first, the robot arm 120 moves the hand 100 so that the second reference axis α is tilted relative to the axis N of the hole H and the workpiece W1 is in point contact with the opening edge of the hole H. At this time, since the restraint 9 restrains the tilt connector 47, the gripper 3 and the workpiece W1 can be positioned with good accuracy. And when the workpiece W1 is inserted into the hole H, the restraint of the tilt connector 47 by the restraint 9 is released. The rotational tilt insertion is performed, in which the workpiece W1 is inserted into the hole H by rotating the workpiece W1 around the second reference axis α from the state in which the second reference axis α is tilted relative to the axis N of the hole H and the workpiece W1 is in point contact with the opening edge of the hole H. According to the rotational tilt insertion, the workpiece W1 is guided to the opening edge of the hole H, and the introduction of the workpiece W1 into the hole H is smoothly performed. The connector 4 can support the gripper 3 tiltably relative to the first reference axis X, and transmit the driving force of the rotary actuator 7 to the gripper 3 in a state in which the second reference axis α is tilted relative to the first reference axis X. Therefore, the gripper 3 can continue to rotate around the second reference axis α while changing its posture as the workpiece W1 is introduced into the hole H so that the second reference axis α is aligned with the axis N of the hole H. Such an action of the gripper 3 can be achieved by the flexible support of the gripper 3 by the connector 4 without moving the hand body 2.

[0294]

[18] In the robot system 1000 described in any one of

[15] to

[17] , the connector 4 further includes an eccentric connector 41, and transmits the driving force of the rotary actuator 7 to the gripper 3 in a state where the second reference axis α is eccentric with respect to the first reference axis X. After the control device 130 partially inserts the workpiece W1 gripped by the gripper 3 into the hole H, it moves the robot arm 120 in a manner that the first reference axis X is substantially parallel to the axis N of the hole H, and then further inserts the workpiece W1 into the hole H by moving the rotary actuator 7.

[0295] According to this structure, after the workpiece W1 is partially inserted into the hole H by rotation and tilt insertion, the robot arm 120 moves so that the first reference axis X is substantially parallel to the axis N of the hole H. Since the workpiece W1 is inserted into the hole H, the second reference axis α is aligned with the axis N. Therefore, the first reference axis X and the second reference axis α are aligned with each other or substantially parallel. The connector 4 can support the holder 3 eccentrically with respect to the first reference axis X, and at the same time, the driving force of the rotary actuator 7 can be transmitted to the holder 3 in a state where the second reference axis α is eccentric with respect to the first reference axis X. Therefore, the hand 100 can rotate the holder 3 around the second reference axis α by the rotary actuator 7 in a state where the second reference axis α is aligned with the first reference axis X or eccentric. As a result, the workpiece W1 is inserted into the hole H while rotating around the axis N. At this time, since the first reference axis X and the axis N are aligned with each other or substantially parallel, the wear of the workpiece W1 to the hole H can be reduced compared with when the first reference axis X and the axis N are tilted. As a result, the workpiece W1 can be inserted into the hole H smoothly.

[0296]

[19] In the robot system 1000 described in any one of

[15] to

[18] , the control device 130 moves the robot arm 120 in such a manner that the workpiece W1 held by the gripper 3 contacts the opening edge of the hole H at a point while the inclined connector 47 is constrained by the constrainer 9 and the first reference axis X intersects with the vertical direction.

[0297] According to this structure, since the first reference axis X of the hand body 2 intersects with the vertical direction, the gripper 3 is eccentric or tilted due to its own weight and the load of the workpiece W1 when the restraint 9 is released. Depending on the angle of the first reference axis X relative to the vertical direction and the distance between the gripper 3 and the restraint 9, the eccentric or tilted gripper 3 sometimes contacts the restraint 9. Even in such a case, the restraint 9 elastically supports the gripper 3. That is, the restraint 9 supports the gripper 3 without hindering the movement of the gripper 3. As a result, smooth movement of the gripper 3 is achieved.

[0298]

[20] In the robot system 1000 described in any one of

[15] to

[19] , the gripper 3 is configured to move straight in the direction of a predetermined first reference axis X relative to the hand body 2, and the restraint 9 has a first retainer 91 and a second retainer 92 and a restraint actuator 93, the first retainer 91 and the second retainer 92 contact the gripper 3 in the restrained state, and the restraint actuator 93 causes the first retainer 91 and the second retainer 92 to open and close, and the first retainer 91 and the second retainer 92 are moved relative to the first The robot arm 120 is switched between a contact state toward the gripper 3 and a separation state away from the gripper 3 by performing an opening and closing action in a direction intersecting the direction of the reference axis X, wherein the first retainer 91 contacts the gripper 3 at least at two locations in the contact state, and the second retainer 92 contacts the gripper 3 at one location in the contact state. When the control device 130 causes the workpiece W1 held by the gripper 3 to be inserted into the hole H, the robot arm 120 is moved in such a manner that the first reference axis X intersects with the vertical direction and the second retainer 92 is located at a lower position than the first retainer 91.

[0299] According to this structure, when the distance between the first retainer 91 and the second retainer 92 and the gripper 3 is not too far in the released state of the restrainer 9, the gripper 3 is relatively displaced and may come into contact with the first retainer 91 and the second retainer 92. Since the second retainer 92 is located at a lower position than the first retainer 91, the second retainer 92 can support the gripper 3 that is displaced due to its own weight. Since the second retainer 92 supports the gripper 3 at one place, the gripper 3 can move along the shape of the second retainer 92. That is, the second retainer 92 can support the weight of the gripper 3 while the connector 4 can function.

[0300] That is to say, when the restraint device 9 is in a restrained state, the holder 3 can be held with a higher position accuracy by the first retainer 91 and the second retainer 92, and when the restraint device 9 is in a released state, the holder 3 can be supported by the second retainer 92 in a relatively displaceable state.

Claims

1. A hand, characterized in that: The hand comprises a hand body, a gripper, a connector and a restraint, wherein the gripper grips a workpiece, the connector connects the gripper to the hand body in a manner that can change the relative position of the gripper relative to the hand body, and the restraint restrains the movement of the connector. The restraint switches between a restraint state and a release state through an opening and closing action. In the restraint state, the movement of the connector is restrained by contacting the holder, and in the release state, the movement of the connector is released from the restraint by moving away from the holder.

2. The hand according to claim 1, characterized in that: The restraint has a first elastic member and restrains the movement of the connector by elastically holding the holder in the restrained state.

3. The hand according to claim 2, characterized in that: The restraint device comprises a first retainer and a second retainer and a restraint actuator, wherein the first retainer and the second retainer contact the holder in the restraint state, and the restraint actuator causes the first retainer and the second retainer to perform an opening and closing action. The constraint actuator comprises a constraint driving source and a constraint transmission, wherein the constraint driving source generates a driving force, and the constraint transmission connects the constraint driving source and the first retainer and the second retainer to transmit the driving force of the constraint driving source to the first retainer and the second retainer. The first elastic member is included in the constraining transmission.

4. The hand according to claim 3, characterized in that: The restraint transmission has a first transmission and a second transmission, the first transmission receives a driving force from the restraint driving source, and the second transmission transmits the driving force to the first holder and the second holder, The first elastic member elastically connects the first transmitter and the second transmitter.

5. The hand according to claim 1, characterized in that: The restraint device comprises a first retainer and a second retainer and a restraint actuator, wherein the first retainer and the second retainer contact the holder in the restraint state, and the restraint actuator causes the first retainer and the second retainer to perform an opening and closing action. The first retainer and the second retainer switch between a contact state with the holder and a separation state from the holder by performing an opening and closing action. The first retainer is in contact with the holder at least at two locations in the contact state, The second retainer is in contact with the gripper at one place in the contact state.

6. The hand according to claim 5, characterized in that: The gripper is configured to move straightly in the direction of a predetermined first reference axis relative to the hand body. The first retainer and the second retainer perform an opening and closing operation in a direction intersecting with a direction of the first reference axis. When the hand is in a posture in which the first reference axis intersects the vertical direction, the second holder is located at a position lower than the first holder.

7. The hand according to claim 1, characterized in that: The gripper is configured to move straightly in the direction of a predetermined first reference axis relative to the hand body. The restraint device comprises a first retainer and a second retainer, a restraint actuator and a buffer, the first retainer and the second retainer contact the holder in the restrained state, the restraint actuator causes the first retainer and the second retainer to open and close, and the buffer elastically supports the first retainer and the second retainer in the direction of the first reference axis. The buffer includes a guide that guides the first retainer and the second retainer so as to be displaceable in the direction of the first reference axis, and a second elastic member that elastically supports the first retainer and the second retainer along the guide.

8. The hand according to claim 1, characterized in that: The hand body has a straight-moving actuator, and the straight-moving actuator causes the gripper to move straight relative to the hand body in a direction of a predetermined first reference axis. The restraint device comprises a first retainer and a second retainer and a restraint actuator, wherein the first retainer and the second retainer contact the holder in the restraint state, and the restraint actuator causes the first retainer and the second retainer to perform an opening and closing action. The linear actuator comprises a linear drive source and a linear transmission, wherein the linear drive source generates a driving force, and the linear transmission transmits the driving force of the linear drive source to the gripper. The constraint actuator comprises a constraint driving source and a constraint transmission, wherein the constraint driving source generates a driving force, and the constraint transmission connects the constraint driving source and the first retainer and the second retainer to transmit the driving force of the constraint driving source to the first retainer and the second retainer. The straight driving source and the restricting driving source are common.

9. The hand according to claim 1, characterized in that: A predetermined first reference axis is defined in the hand body, A predetermined second reference axis is defined in the holder, The connector includes at least one of an eccentric connector and an inclined connector, wherein the eccentric connector supports the holder in a manner that the second reference axis can be eccentric relative to the first reference axis, and the inclined connector supports the holder in a manner that the second reference axis can be inclined relative to the first reference axis.

10. The hand according to claim 9, characterized in that: The connector includes both the eccentric connector and the tilted connector.

11. The hand according to claim 9, characterized in that: The restraint restrains the movement of the connector in a state where the first reference axis and the second reference axis are aligned on a straight line.

12. The hand according to claim 9, characterized in that: The hand body has an opening and closing actuator, and the opening and closing actuator opens and closes the gripper. The connector has a power transmitter, which transmits the driving force of the opening and closing actuator to the holder. The power transmitter transmits the driving force of the opening and closing actuator to the holder in a state where the second reference axis is eccentric or inclined with respect to the first reference axis.

13. The hand according to claim 12, characterized in that: The opening and closing actuator includes an opening and closing drive source and an opening and closing shaft, wherein the opening and closing drive source generates a driving force, and the opening and closing shaft extends around the first reference axis as an axis and is rotated around the first reference axis by the driving force of the opening and closing drive source. The power transmission device comprises a first joint, wherein the first joint connects the opening and closing shaft and the holder. The connector includes the tilted connector, The first joint transmits the rotation of the opening and closing axis to the holder in a state where the second reference axis is inclined relative to the first reference axis. The holder has a base and a plurality of fingers, wherein the plurality of fingers are supported by the base and perform opening and closing actions through the rotation of the opening and closing shaft.

14. The hand according to claim 13, characterized in that: The connector further comprises the eccentric connector, The first joint transmits the rotation of the opening and closing axis to the holder in a state where the second reference axis is eccentric with respect to the first reference axis.

15. A robot system, characterized in that: The robot system comprises the hand according to claim 1, a robot arm and a control device, wherein the robot arm is connected to the hand, and the control device controls the robot arm and the hand. The control device causes the robot arm and the hand to perform an insertion operation in which the workpiece held by the hand is inserted into a predetermined hole.

16. The robot system according to claim 15, characterized in that: A predetermined first reference axis is defined on the hand body, A predetermined second reference axis is defined in the holder, The connector includes at least one of an eccentric connector and an inclined connector, wherein the eccentric connector supports the holder in a manner that the second reference axis can be eccentric relative to the first reference axis, and the inclined connector supports the holder in a manner that the second reference axis can be inclined relative to the first reference axis. The control device causes the workpiece held by the holder to be inserted into the hole in a state in which the second reference axis is eccentric or inclined with respect to the axis of the hole.

17. The robot system according to claim 16, characterized in that: The hand body has a rotary actuator, which is connected to the connector to rotate the gripper around the second reference axis. The connector includes the tilting connector, and transmits the driving force of the rotary actuator to the holder in a state where the second reference axis is tilted relative to the first reference axis. The control device operates the robot arm in such a manner that the workpiece held by the holder is brought into point contact with the opening edge of the hole in a state where the inclined connector is constrained by the constrainer and the second reference axis is inclined relative to the axis of the hole. The workpiece is inserted into the hole by operating the rotary actuator in a state where the restraint of the tilt connector by the restrainer is released.

18. The robot system according to claim 17, characterized in that: The connector further includes the eccentric connector, and transmits the driving force of the rotary actuator to the holder in a state where the second reference axis is eccentric with respect to the first reference axis. After partially inserting the workpiece held by the gripper into the hole, the control device operates the robot arm so that the first reference axis is substantially parallel to the axis of the hole, and then operates the rotary actuator to further insert the workpiece into the hole.

19. The robot system according to claim 17, characterized in that: The control device operates the robot arm so that the workpiece gripped by the gripper is brought into point contact with the opening edge of the hole in a state where the tilt connector is restrained by the restrainer and the first reference axis intersects with the vertical direction.

20. The robot system according to claim 19, characterized in that: The gripper is configured to move straightly in the direction of a predetermined first reference axis relative to the hand body. The restraint device comprises a first retainer and a second retainer and a restraint actuator, wherein the first retainer and the second retainer contact the holder in the restraint state, and the restraint actuator causes the first retainer and the second retainer to perform an opening and closing action. The first retainer and the second retainer switch between a contact state with the holder and a separation state from the holder by opening and closing in a direction intersecting with the direction of the first reference axis. The first retainer is in contact with the holder at least at two locations in the contact state, The second retainer is in contact with the gripper at one place in the contact state, When inserting the workpiece held by the holder into the hole, the control device operates the robot arm so that the first reference axis intersects the vertical direction and the second holder is located lower than the first holder.

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