Robotic hand

Abstract

To provide a robotic hand that is suited to objects having wide range sizes.SOLUTION: A robotic hand (100) includes a gripping mechanism (20) and a drive part (30). The gripping mechanism includes: a third rail member (213a) slidable to a first rail member (211a); and a third block member (213b) connected to the third rail member so as to be slidable. The drive part imparts drive power to the third block member not through the third rail member.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a robot hand. [Background technology]

[0002] Robots equipped with robotic hands for gripping objects are widely known. Robotic hands are typically used in the form of two-fingered parallel grippers. Here, a two-fingered parallel gripper refers to a robotic hand having a mechanism in which a pair of gripping portions (fingers) move toward or away from each other, gripping an object by the pair of gripping portions approaching each other. Robots equipped with such robotic hands can be used for pick-and-place operations and object fixing operations in manufacturing sites such as factories.

[0003] Known mechanisms for two-fingered parallel gripper robot hands include a link type using a bar linkage and a linear type using a linear slider. Link type and linear type robot hands are disclosed in, for example, the following Patent Documents 1 to 3. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 5351161 [Patent Document 2] Japanese Patent Publication No. 2021-133444 [Patent Document 3] Patent Publication No. 2021-70076 Summary of the Invention [Problem to be solved by the invention]

[0005] In a link-type robot hand, the rotational movement of a link member extending from a base is converted into horizontal movement of a gripper attached to the tip of the link member. The opening width of the gripper is approximately 10 to 20 cm. Furthermore, the gripper does not move perfectly along a straight line, but rather along a curved line within a plane. Therefore, when the gripper grasps an object, the object is subjected to pressure from the gripper and a tangential frictional force. Therefore, there is a possibility that the gripper will not be able to grasp the object stably.

[0006] On the other hand, linear robotic hands use a linear slider to move the gripper, which moves horizontally along a straight line. Therefore, when the gripper grips an object, the object is only subjected to pressure from the gripper. Therefore, linear robotic hands have the advantage of being able to grip objects stably.

[0007] However, the movable range of the gripper in conventional linear robotic hands is limited by the length of the linear slider. Therefore, the opening width of the gripper is typically about 2 to 6 cm. To grip a large object, it is necessary to increase the length of the linear slider or use a gripper that cannot be completely closed, but such robotic hands are disadvantageous for gripping small objects. In other words, conventional linear robotic hands have difficulty handling objects of a wide range of sizes.

[0008] An object of one aspect of the present invention is to realize a robot hand that is adaptable to objects of a wide range of sizes. [Means for solving the problem]

[0009] In order to solve the above problem, a robot hand according to aspect 1 of the present invention comprises a base, a gripping mechanism, and a drive unit, wherein the gripping mechanism comprises a first slide portion slidable along a first direction relative to the base, a second slide portion connected to the first slide portion slidably along the first direction, and a gripping portion provided on the second slide portion, and the drive unit applies a drive force to the second slide portion for movement in the first direction without passing through the first slide portion.

[0010] In a robot hand according to aspect 2 of the present invention, in the above aspect 1, the gripping mechanism may include a first rotating member having a slide axis and fixed to the base so as to rotate around a first axis extending in a second direction perpendicular to the first direction, and a slide member fixed to the second slide portion so as to rotate around a second axis extending in the second direction and sliding along the slide axis of the first rotating member.

[0011] In a robot hand according to a third aspect of the present invention, in the second aspect, the slide member may be fixed to the second slide portion at a position offset from the slide axis.

[0012] In a robot hand according to aspect 4 of the present invention, in aspect 3 above, the slide member may have a first portion that is aligned with the slide axis and a second portion that is aligned with the first direction when the gripping portion is fully open.

[0013] In a robot hand according to aspect 5 of the present invention, in any of aspects 1 to 4 above, the drive unit may control the drive force applied to the second slide portion according to the position of the second slide portion in the first direction.

[0014] In a robot hand according to aspect 6 of the present invention, in the above aspect 1, a second rotating member is provided that is fixed to the base so as to rotate around a third axis extending in a third direction perpendicular to the first direction, and the gripping mechanism may include a chain member that connects the second sliding portion and the second rotating member and converts the rotational drive of the second rotating member into a sliding drive of the second sliding portion in the first direction.

[0015] In a robot hand according to aspect 7 of the present invention, in any of aspects 1 to 6 above, when the gripping portion opens from a completely closed state, the second sliding portion may slide before the first sliding portion.

[0016] In a robot hand according to aspect 8 of the present invention, in aspect 7 above, the base has an engaged portion, the first slide portion has an engaging portion that can engage with the engaged portion, and when the engaging portion is engaged with the engaged portion, it does not move from the engaged portion with a predetermined driving force, and when the gripping portion is completely closed, the second slide portion can slide with the predetermined driving force, and the engaging portion may be engaged with the engaged portion. [Effects of the Invention]

[0017] According to one aspect of the present invention, a robot hand that is adaptable to objects of a wide range of sizes can be realized. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a perspective view showing the external configuration of a robot hand according to a first embodiment of the present invention. FIG. [Figure 2] FIG. 2 is a front view of the robot hand in a state where the gripping portion is completely closed. [Figure 3] FIG. 10 is a front view of the robot hand in a state between a state in which the gripper is fully closed and a state in which the gripper is fully open. [Figure 4] FIG. 2 is a front view of the robot hand with the gripping portion fully open. [Figure 5]FIG. 10 is a top view of the robot hand with the gripping portion completely closed. [Figure 6] FIG. 10 is a top view of the robot hand with the gripper fully open. [Figure 7] FIG. 2 is a longitudinal cross-sectional view of the robot hand in a state where the gripping portion is completely closed. [Figure 8] FIG. 10 is a longitudinal cross-sectional view of the robot hand in a state between a state in which the gripper is fully closed and a state in which the gripper is fully open. [Figure 9] FIG. 2 is a longitudinal cross-sectional view of the robot hand with the gripping portion fully open. [Figure 10] FIG. 10 is a perspective view showing the external configuration of a robot hand according to a second embodiment of the present invention. [Figure 11] FIG. 2 is a front view of the robot hand in a state where the gripping portion is completely closed. [Figure 12] FIG. 2 is a front view of the robot hand with the gripping portion fully open. [Figure 13] FIG. 10 is a top view of the robot hand with the gripping portion completely closed. [Figure 14] FIG. 10 is a top view of the robot hand with the gripper fully open. [Figure 15] 12 is a cross-sectional view of the robot hand taken along the line AA in FIG. 11. DETAILED DESCRIPTION OF THE INVENTION

[0019] [Embodiment 1] (Schematic configuration of the robot hand 100) Fig. 1 is a perspective view showing the external configuration of a robot hand 100 according to this embodiment. As shown in Fig. 1, the robot hand 100 includes a base 10 (base), a pair of gripping mechanisms 20-1 and 20-2, and a drive unit 30. Note that in Fig. 1, in order to show the configuration of the drive unit 30, part of the side wall of the base 10 is not shown.

[0020] Each of the pair of gripping mechanisms 20-1, 20-2 has a structure that is approximately symmetrical with respect to a predetermined axis (an axis along the vertical direction). Hereinafter, unless there is a particular need to distinguish between them, the pair of gripping mechanisms 20-1, 20-2 will be simply referred to as gripping mechanisms 20. The same applies to each member included in the pair of gripping mechanisms 20-1, 20-2.

[0021] The gripping mechanism 20 includes a linear slide unit 21, a power transmission unit 22, and a gripping unit 23. The linear slide unit 21 is provided on a first surface (top surface) of the base 10, and is a member that deploys and retracts along a first direction. The power transmission unit 22 is a member that transmits a driving force (torque) from a drive unit 30 (described later) to the linear slide unit 21. The gripping unit 23 is provided on the linear slide unit 21, and is a member that moves along the first direction as the linear slide unit 21 deploys and retracts. The gripping unit 23 opens and closes to grip an object.

[0022] In detail, the gripping mechanism 20-1 is connected to one side of the first surface of the base 10, and the gripping mechanism 20-2 is connected to the other side of the first surface of the base 10. The linear slide portion 21-1 of the gripping mechanism 20-1 deploys in one direction in the first direction, and the linear slide portion 21-2 of the gripping mechanism 20-2 deploys in the other direction in the first direction. As the linear slide portion 21 deploys, the gripping portion 23-1 of the gripping mechanism 20-1 moves in one direction in the first direction, and the gripping portion 23 of the gripping mechanism 20-2 moves in the other direction in the first direction. As a result, the pair of gripping portions 23-1, 23-2 move apart. Similarly, as the linear slide portion 21 retracts, the pair of gripping portions 23-1, 23-2 move closer to each other. That is, the gripping portion 23 performs an opening and closing operation.

[0023] Hereinafter, the side of the base 10 where the first surface is located will be referred to as the upper side, and the opposite side will be referred to as the lower side. Furthermore, the side of the first surface of the base 10 where the gripping mechanism 20-1 is provided will be referred to as the front side, and the opposite side will be referred to as the rear side. Furthermore, the side where the gripping mechanism 20-1 unfolds will be referred to as the left side, and the opposite side will be referred to as the right side. In other words, the first direction will be referred to as the left-right direction.

[0024] The linear slide unit 21 includes a first slide unit that is slidable in the left-right direction (first direction) relative to the base unit, and a second slide unit that is connected to the first slide unit so as to be slidable in the left-right direction. The grip unit 23 is provided on the second slide unit.

[0025] In this embodiment, the linear slide portion 21 includes a first linear slide 211, a second linear slide 212, and a third linear slide 213. The first linear slide 211, the second linear slide 212, and the third linear slide 213 are mechanisms that guide linear motion. Each of the first linear slide 211, the second linear slide 212, and the third linear slide 213 may be a linear guide or a linear bushing.

[0026] The first linear slide 211 is fixed to the upper surface of the base 10 and includes a first rail member 211a having a rail portion extending in the left-right direction and a first block member 211b having a rail engagement portion that engages with the rail portion. The second linear slide 212 is fixed to the upper surface of the first block member 211b and includes a second rail member 212a having a rail portion extending in the left-right direction and a second block member 212b having a rail engagement portion that engages with the rail portion. The third linear slide 213 is fixed to the upper surface of the second block member 212b and includes a third rail member 213a having a rail portion extending in the left-right direction and a third block member 213b having a rail engagement portion that engages with the rail portion. The gripper 23 is provided on the third block member 213b.

[0027] That is, in this embodiment, the first rail member 211a of the first linear slide 211 corresponds to the base portion. Furthermore, the first block member 211b of the first linear slide 211, the second linear slide 212, and the third rail member 213a of the third linear slide 213 correspond to the first slide portion. Furthermore, the third block member 213b of the third linear slide 213 corresponds to the second slide portion.

[0028] The movements of the first block member 211b, the second block member 212b, and the third block member 213b are restricted to sliding in the left and right directions by the first rail member 211a, the second rail member 212a, and the third rail member 213a, respectively.

[0029] Each of the rail members 211a to 213a has, for example, a bottom plate, extension plates extending upward from the left and right ends of the bottom plate, and a rail portion extending from the inner surface of one extension plate to the inner surface of the other extension plate.

[0030] In this embodiment, the gripping mechanism 20 of the robot hand 100 is described as having three linear slides, but the number of linear slides is not limited to this, and the gripping mechanism 20 may have two linear slides, or may have four or more linear slides.

[0031] The power transmission unit 22 includes a first rotating member 221 and a slide member 222. The power transmission unit 22 transmits the driving force of the drive unit 30, which will be described later, to the linear slide unit 21. Due to the configuration of the power transmission unit 22 described below, the drive unit 30 applies the driving force for moving in the left-right direction to the third block member 213b without passing through other members of the linear slide unit 21.

[0032] The first rotating member 221 is fixed to the base 10 so as to rotate about a first axis extending in the front-rear direction (second direction). The first rotating member 221 in the gripping mechanism 20-1 has a bearing portion 221a that rotatably supports the rotation shaft of a first gear 31 described later. The first rotating member 221 in the gripping mechanism 20-1 is provided on the left side of the front surface of the base 10. The first rotating member 221 in the gripping mechanism 20-2 has a bearing portion 221a that rotatably supports the rotation shaft of a fourth gear 34 described later. The first rotating member 221 in the gripping mechanism 20-2 is provided on the right side of the rear surface of the base 10.

[0033] The first rotating member 221 also has a slide shaft. That is, the first rotating member 221 has a linear guide rail 221b. The bearing portion 221a is provided on one end side of the slide shaft.

[0034] The slide member 222 is fixed to the third block member 213b (second slide portion) so as to rotate about a second axis extending in the front-rear direction. The slide member 222 has a bearing portion 222a that rotatably supports the axis extending in the front-rear direction from the third block member 213b.

[0035] Furthermore, the slide member 222 slides along the slide axis of the first rotating member 221. The slide member 222 has an engagement block member 222b that engages with the linear guide rail 221b of the first rotating member 221.

[0036] Specifically, the slide member 222 is fixed to the third block member 213b at a position offset from the slide axis of the first rotating member 221. More specifically, the slide member 222 has a first portion 2221 that is aligned with the slide axis of the first rotating member 221, and a second portion 2222 that is aligned with an axis offset from the slide axis of the first rotating member 221. The second portion 2222 is aligned in the left-right direction when the grip portion 23 is fully opened. An engagement block member 222b is provided on the first portion 2221, and a bearing portion 222a is provided on the second portion 2222.

[0037] The gripping portion 23 is a member extending upward from the outer end of the third block member 213b in the left-right direction. The gripping portions 23 of the pair of gripping mechanisms 20-1, 20-2 each have gripping surfaces 23a that are perpendicular to the left-right direction and overlap when viewed from the left-right direction. The gripping portions 23 grip an object by moving the gripping surfaces 23a closer to each other. Hereinafter, the distance between the gripping surfaces 23a of the gripping portion 23 of the gripping mechanism 20-1 and the gripping surfaces 23a of the gripping portion 23 of the gripping mechanism 20-2 will be referred to as the opening width of the gripping portion 23. Note that FIG. 1 shows only a portion of the gripping portion 23, and the gripping portion 23 may extend further upward than shown in FIG. 1.

[0038] The driving unit 30 includes a first gear 31, a second gear 32, a third gear 33, a fourth gear 34, and a motor 35. The driving unit 30 applies a driving force to the linear slide unit 21 to move it in the left-right direction.

[0039] The first gear 31 is a circular gear connected to the rotation shaft of the motor 35. The first gear 31 is rotationally driven by the motor 35. The second gear 32 is a circular gear meshing with the first gear 31. The third gear 33 is a circular gear meshing with the second gear 32. The fourth gear 34 is a circular gear meshing with the third gear 33.

[0040] The rotation shaft of the first gear 31 is journaled to a bearing 221a of the first rotating member 221 in the gripping mechanism 20-1. In addition, the rotation shaft of the fourth gear 34 is journaled to a bearing 221a of the first rotating member 221 in the gripping mechanism 20-2. As a result, the driving force of the motor 35 rotates the first rotating member 221 via the first gear 31 to the fourth gear 34. In a front view, when the first rotating member 221 in the gripping mechanism 20-1 rotates counterclockwise, the first rotating member 221 in the gripping mechanism 20-2 rotates clockwise.

[0041] (Operation of the gripping mechanism 20) FIG. 2 is a front view of the robot hand 100 when the gripper 23 is fully closed. FIG. 3 is a front view of the robot hand 100 when the gripper 23 is in a state between a fully closed state and a fully open state. FIG. 4 is a front view of the robot hand 100 when the gripper 23 is fully open. FIG. 5 is a top view of the robot hand 100 when the gripper 23 is fully closed. FIG. 6 is a top view of the robot hand 100 when the gripper 23 is fully open. With reference to FIGS. 2 to 6, the operation of the gripping mechanism 20 from a state in which the gripper 23 is fully closed to a state in which the gripper 23 is fully open will be described below. Note that the "state in which the gripper 23 is fully closed" refers to a state in which the gripper 23 has the smallest opening width, and the "state in which the gripper 23 is fully open" refers to a state in which the gripper 23 has the largest opening width. For ease of explanation, only the operation of the gripping mechanism 20-1 will be described below. The gripping mechanism 20-2 operates symmetrically compared to the gripping mechanism 20-1.

[0042] 2 and 5, when the block member of each linear slide of gripping mechanism 20-1 is located at the right end of the rail member, gripping unit 23 is completely closed. At this time, the second shaft (bearing portion 222a) is located to the upper right of the first shaft (bearing portion 221a), and slide member 222 is located at the first position on the slide shaft of first rotating member 221.

[0043] When the drive unit 30 applies a counterclockwise rotational force to the first rotating member 221 while the gripping unit 23 is fully closed, the gripping unit 23 opens (i.e., the linear slide unit 21 unfolds). In particular, as the first rotating member 221 rotates counterclockwise, the slide member 222 applies a leftward driving force to the third block member 213b fixed to the slide member 222. As a result, the third block member 213b, which is located at the right end of the third rail member 213a, slides leftward. The slide member 222 slides from the first position toward one end along the slide axis of the first rotating member 221.

[0044] 3 shows a state in which the third block member 213b is positioned at the left end of the third rail member 213a, and the other block members are positioned at the right end of the rail members. As shown in FIG. 3, when at least the third block member 213b is positioned to the left of the right end of the third rail member 213a, the gripper 23 is in a state between a fully closed state and a fully open state. At this time, the second shaft is positioned approximately directly above the first shaft, and the sliding member 222 is positioned at a second position that is one end closer to the first position on the sliding shaft of the first rotating member 221.

[0045] In the state shown in FIG. 3, when the drive unit 30 applies a counterclockwise rotational drive force to the first rotating member 221, the gripping unit 23 opens further. Specifically, as the first rotating member 221 rotates counterclockwise, the slide member 222 similarly applies a leftward driving force to the third block member 213b. This causes the third rail member 213a and the second block member 212b located at the right end of the second rail member 212a to slide leftward. When the second block member 212b slides to the left end of the second rail member 212a, the second rail member 212a and the first block member 211b located at the right end of the first rail member 211a also slide leftward. The slide member 222 slides from the second position toward the other end along the slide axis of the first rotating member 221.

[0046] 4 and 6, when the block member of each linear slide of gripping mechanism 20-1 is located at the left end of the rail member, gripping section 23 is fully open. At this time, the second axis is located above and to the left of the first axis, and slide member 222 is located at a third position on the other end side of the first position on the slide axis of first rotating member 221.

[0047] As shown in FIGS. 2 and 5, in the stored state, the first linear slide 211, the second linear slide 212, and the third linear slide 213 are aligned in the left-right direction when viewed from above.

[0048] (About the stopper mechanism) FIG. 7 is a longitudinal cross-sectional view of the robot hand 100 when the gripper 23 is fully closed. FIG. 8 is a longitudinal cross-sectional view of the robot hand 100 when the gripper 23 is in a state between a fully closed state and a fully open state. FIG. 9 is a longitudinal cross-sectional view of the robot hand 100 when the gripper 23 is fully open. As shown in FIGS. 2 to 6, when the gripper 23 opens from a fully closed state, the third block member 213b slides before the other members of the linear slide unit 21. A mechanism (stopper mechanism) for causing the third block member 213b to slide before the other members when the linear slide unit 21 is deployed will be described below with reference to FIGS. 7 to 9. For ease of explanation, only the stopper mechanism in the gripping mechanism 20-1 will be described below. The gripping mechanism 20-2 has a stopper mechanism that is arranged symmetrically with respect to the gripping mechanism 20-1.

[0049] 7 to 9, the first rail member 211a has a first engagement hole 211aa (engaged portion) provided at the right end of the bottom plate. The first block member 211b has a first biasing member 211ba extending downward from the rail engagement portion, and a first engagement member 211bb (engaging portion) provided at the lower end of the first biasing member 211ba and engageable with the first engagement hole 211aa. When engaged with the first engagement hole 211aa, the first engagement member 211bb does not move from the first engagement hole 211aa due to a first driving force (a predetermined driving force), but moves from the first engagement hole 211aa due to a second driving force greater than the first driving force.

[0050] The second rail member 212a has a second right-side engagement hole 212aa and a second left-side engagement hole 212ab provided at the right and left ends of the bottom plate, respectively. The second block member 212b has a second biasing member 212ba extending downward from the rail engagement portion, and a second engagement member 212bb provided at the lower end of the second biasing member 212ba and engageable with the second right-side engagement hole 212aa and the second left-side engagement hole 212ab. When the second engagement member 212bb is engaged with the second right-side engagement hole 212aa, it does not move from the second right-side engagement hole 212aa under a first driving force, but moves (relatively) from the second right-side engagement hole 212aa under a third driving force greater than the first driving force. When the second engagement member 212bb is engaged with the second left engagement hole 212ab, it does not move from the second left engagement hole 212ab by the first driving force, but moves (relatively) from the second left engagement hole 212ab by a fourth driving force greater than the first driving force.

[0051] The third rail member 213a has a third engagement hole 213aa provided at the left end of the bottom plate. The third block member 213b has a third biasing member 213ba extending downward from the rail engagement portion and a third engagement member 213bb provided at the lower end of the third biasing member 213ba and engageable with the third engagement hole 213aa. When engaged with the third engagement hole 213aa, the third engagement member 213bb does not move from the third engagement hole 213aa due to a first driving force, but moves (relatively) from the third engagement hole 213aa due to a fifth driving force greater than the first driving force.

[0052] The first biasing member 211ba, the second biasing member 212ba, and the third biasing member 213ba are, for example, springs. The first engagement member 211bb, the second engagement member 212bb, and the third engagement member 213bb are, for example, balls. Note that an engagement hole may be formed in each block member, and an engagement member may be provided on each rail member via a biasing member. The second to fifth driving forces are adjusted by the biasing force of the biasing member and the size of the engagement hole, etc.

[0053] As shown in Fig. 7, when the grip portion 23 is fully closed, the first engagement member 211bb engages with the first engagement hole 211aa, and the second engagement member 212bb engages with the second right engagement hole 212aa. Meanwhile, the third engagement member 213bb is not engaged with an engagement hole and is in contact with the bottom plate of the third rail member 213a. Therefore, when a first driving force, which is a driving force to the left, is applied to the third block member 213b in the state shown in Fig. 7, only the third block member 213b slides leftward.

[0054] As shown in Fig. 8, when the third block member 213b moves to the left end of the third rail member 213a, the third engagement member 213bb engages with the third engagement hole 213aa. Here, the third driving force is smaller than the second driving force. Therefore, when the third driving force, which is a leftward driving force, is applied to the third block member 213b in the state shown in Fig. 8, the second engagement member 212bb moves from the second right engagement hole 212aa, and the third rail member 213a and the second block member 212b slide leftward.

[0055] Similarly, when the second block member 212b moves to the left end of the second rail member 212a, the second engagement member 212bb engages with the second left engagement hole 212ab. When a second driving force, which is a driving force to the left, is applied to the third block member 213b, the first engagement member 211bb moves out of the first engagement hole 211aa, and the second rail member 212a and the first block member 211b slide leftward. As shown in FIG. 9, when the first block member 211b moves to the left end of the first rail member 211a, the gripping portion 23 is fully opened.

[0056] Conversely, when the grip portion 23 is fully open, the second engagement member 212bb engages with the second left engagement hole 212ab, and the third engagement member 213bb engages with the third engagement hole 213aa. Meanwhile, the first engagement member 211bb is not engaged with an engagement hole and abuts against the bottom plate of the first rail member 211a. Therefore, when a first driving force, which is a rightward driving force, is applied to the third block member 213b in the state shown in FIG. 9, only the first block member 211b slides rightward. The first engagement member 211bb engages with the first engagement hole 211aa. Here, the fourth driving force is smaller than the fifth driving force. Therefore, when a fourth driving force, which is a rightward driving force, is applied to the third block member 213b, the second engagement member 212bb moves out of the second left engagement hole 212ab, and the third rail member 213a and the second block member 212b slide rightward.

[0057] Similarly, when the second block member 212b moves to the right end of the second rail member 212a, the second engagement member 212bb engages with the second right engagement hole 212aa (see FIG. 8). Then, when a fifth driving force, which is a rightward driving force, is applied to the third block member 213b, the first engagement member 211bb moves from the first engagement hole 211aa, and the second rail member 212a and the first block member 211b slide rightward. When the third block member 213b moves to the right end of the third rail member 213a, the gripping portion 23 is completely closed (see FIG. 7).

[0058] (Action and effect of the robot hand 100) According to the above configuration, the robot hand 100 is provided with multiple linear slides (three linear slides in this embodiment), and the opening and closing operation of the gripper 23 is realized by deploying and retracting each linear slide. Therefore, the opening width of the gripper 23 can be expanded compared to conventional ones while keeping the dimensions of the robot hand 100 small.

[0059] Furthermore, the drive unit 30 applies the drive force for moving in the left-right direction to the third block member 213b to which the gripper 23 is attached, without going through other members of the linear slide unit 21. Therefore, when gripping a small object, the force applied to the gripper 23 can be easily adjusted. Therefore, the robot hand 100 is advantageous for gripping small objects. As described above, the robot hand 100 can appropriately grip objects of a wide range of sizes.

[0060] Furthermore, the rotational drive by the drive unit 30 can be converted into left-right sliding drive of each linear slide by the power transmission unit 22. Therefore, a wide range of opening and closing operations of the gripping unit 23 can be realized with a simple configuration.

[0061] Furthermore, the sliding member 222 may be fixed to the third block member 213b at a position offset from the sliding axis of the first rotating member 221. In detail, the sliding member 222 has a first portion 2221 that is aligned with the sliding axis of the first rotating member 221, and a second portion 2222, and the second portion 2222 may be aligned in the left-right direction when the gripping portion 23 is fully opened.

[0062] With this configuration, when slide member 222 slides toward one end of first rotating member 221 where bearing portion 221a is located, it is possible to prevent the fixed portion (bearing portion 222a) between slide member 222 and third block member 213b from colliding with linear guide rail 221b (see FIG. 5). Furthermore, when gripping portion 23 is fully opened, second portion 2222 moves along the left-right direction, thereby increasing the maximum opening width of gripping portion 23 (see FIG. 6).

[0063] Furthermore, when the gripper 23 opens from a completely closed state, the third block member 213b slides before the other members of the linear slide unit 21. With this configuration, when gripping a small object, only the third block member 213b slides on the third rail member 213a, so the width of the entire robot hand 100 in the left-right direction remains almost unchanged. Therefore, the robot hand 100 is advantageous for gripping small objects.

[0064] (Variation) The driving unit 30 may control the driving force applied to the third block member 213b depending on the left-right position of the third block member 213b. For example, the torque of the motor 35 may be controlled so that the left-right component of the driving force applied to the third block member 213b (i.e., the force with which the gripper 23 grips the object) remains constant regardless of the open width of the gripper 23. Alternatively, for example, the torque of the motor 35 may be controlled so that the larger the open width of the gripper 23, the larger the left-right component of the driving force applied to the third block member 213b.

[0065] The robot hand 100 may also include only one of the gripping mechanisms 20-1. That is, the robot hand 100 may include the gripping mechanism 20-1 and a gripping unit fixed to the base 10. In this case, the robot hand 100 grips an object with the gripping unit 23-1 of the gripping mechanism 20-1 and the gripping unit fixed to the base 10 by moving the gripping unit 23-1 in the left-right direction.

[0066] [Embodiment 2] Other embodiments of the present invention will be described below. For ease of explanation, the same reference numerals will be used to designate components having the same functions as those described in the above embodiment, and the description thereof will not be repeated.

[0067] FIG. 10 is a perspective view showing the external configuration of a robot hand 100A according to this embodiment. As shown in FIG. 10, the robot hand 100A includes a base 10A (a base), a pair of gripping mechanisms 20A-1 and 20A-2, and a drive unit 30A. As in the first embodiment, the up-down direction, the front-rear direction, and the left-right direction of the robot hand 100A are defined. Each of the pair of gripping mechanisms 20A-1 and 20A-2 has a structure that is approximately symmetrical with respect to an axis along the up-down direction. The configuration of the gripping mechanism 20A-1 will be described below as a representative example.

[0068] The gripping mechanism 20A includes a linear slide portion 21A, a chain member 22A, and a gripping portion .

[0069] The linear slide portion 21A differs from the linear slide portion 21 according to embodiment 1 in that it is provided on the front and rear surfaces of the base 10A. In detail, the linear slide portion 21A includes a first linear slide 211A and a second linear slide 212A (see also FIG. 15).

[0070] The first linear slide 211A has a first rail member 211aA and a first block member 211bA. The first rail member 211aA has side plates fixed to the front surface of the base 10A, extension plates extending forward from the left and right ends of the side plates, and rail portions extending from the inner surface of one extension plate to the inner surface of the other extension plate. The first block member 211bA has a rail engagement portion that engages with the rail portions of the first rail member 211aA.

[0071] The second linear slide 212A has a second rail member 212aA and a second block member 212bA. The second rail member 212aA has side plates fixed to the front surface of the first block member 211bA, extension plates extending rearward from the left and right ends of the side plates, and a rail portion extending from the inner surface of one extension plate to the inner surface of the other extension plate. The second block member 212bA has a rail engagement portion that engages with the rail portion of the second rail member 212aA. The gripper 23 is provided on the second block member 212bA.

[0072] That is, in this embodiment, the first rail member 211aA of the first linear slide 211A corresponds to the base portion. Furthermore, the first block member 211bA of the first linear slide 211A and the second rail member 212aA of the second linear slide 212 correspond to the first slide portion. Furthermore, the second block member 212bA of the second linear slide 212A corresponds to the second slide portion.

[0073] The chain member 22A connects the second block member 212bA and a second rotating member 31A (described later), and converts the rotational drive of the second rotating member 31A into a sliding drive of the second rotating member 31A in the left-right direction. The chain member has a connecting portion and has a plurality of chain elements that are connected to each other.

[0074] The driving unit 30A includes a second rotating member 31A and a motor 32A. The second rotating member 31A is fixed to the base 10A so as to rotate about an axis (third axis) extending in the vertical direction (third direction). The rotation axis of the second rotating member 31A is connected to the rotation axis of the motor 35.

[0075] (Operation of the gripping mechanism 20A) Fig. 11 is a front view of the robot hand 100A when the gripper 23 is fully closed. Fig. 12 is a front view of the robot hand 100A when the gripper 23 is fully open. Fig. 13 is a top view of the robot hand 100A when the gripper 23 is fully closed. Fig. 14 is a top view of the robot hand 100A when the gripper 23 is fully open. Below, the operation of the gripping mechanism 20A-1 will be described as a representative example.

[0076] 11 and 13, when the block member of each linear slide of gripping mechanism 20A-1 is positioned at the right end of the rail member, gripping portion 23 is fully closed. At this time, chain member 22A connects second block member 212bA and second rotating member 31A in a curved state.

[0077] When the second rotating member 31A rotates counterclockwise while the gripping portion 23 is fully closed, the second block member 212bA connected to the second rotating member 31A via the chain member 22A first slides leftward along the second rail member 212aA, thereby opening the gripping portion 23. The second block member 212bA slides to the left end of the second rail member 212aA.

[0078] As the second rotating member 31A further rotates counterclockwise, the first block member 211bA fixed to the second rail member 212aA slides leftward along the first rail member 211aA, thereby further opening the gripping portion 23. As shown in FIGS. 12 and 14, when the first block member 211bA slides to the left end of the first rail member 211aA, the gripping portion 23 is fully open.

[0079] The gripping mechanism 20A may include the stopper mechanism described in embodiment 1. The stopper mechanism may cause the second block member 212bA to slide before the first block member 211bA during the unfolding operation of the multiple linear slides. Also, the stopper mechanism may cause the first block member 211bA to slide before the second block member 212bA during the retracting operation of the multiple linear slides.

[0080] (Action and effect of Robot Hand 100A) Fig. 15 is a cross-sectional view of the robot hand 100A taken along the line AA in Fig. 11. As shown in Fig. 15, the robot hand 100A includes a plurality of linear slides provided on the side surface of the base 10 and the chain member 22A described above. With this configuration, the robot hand 100A can achieve the same effects as the robot hand 100 according to the first embodiment.

[0081] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention. [Explanation of symbols]

[0082] 100, 100A Robot Hand 10, 10A base (base) 20, 20A gripping mechanism 21, 21A Linear slide section 211, 211A First Linear Slide 211a, 211aA First rail member (base) 211aa 1st engagement hole (engaged part) 211b, 211bA First block member (first slide portion) 211bb First engaging member (engaging portion) 212, 212A Second Linear Slide 212a, 212aA Second rail member (first slide portion) 212b, 212bA Second block member (first slide portion, second slide portion) 213 3rd Linear Slide 213a third rail member (first slide portion) 213b Third block member (second slide portion) 22A Chain member 221 First rotating member 222 Slide member 2221 Part 1 2222 Part 2 23 Gripping part 30, 30A drive unit 31A Second rotating member

Claims

1. A base and A gripping mechanism; a drive unit, The gripping mechanism includes: a first sliding portion slidable along a first direction relative to the base portion; a second slide portion connected to the first slide portion so as to be slidable along the first direction; a grip portion provided on the second slide portion, The driving unit applies a driving force for moving in the first direction to the second sliding unit without passing through the first sliding unit.

2. The gripping mechanism includes: a first rotating member fixed to the base portion so as to rotate about a first axis extending in a second direction perpendicular to the first direction, the first rotating member having a slide shaft; 2. The robot hand according to claim 1, further comprising: a slide member that is fixed to the second slide portion so as to rotate about a second axis extending in the second direction, and that slides along the slide axis of the first rotating member.

3. The robot hand according to claim 2 , wherein the slide member is fixed to the second slide portion at a position offset from the slide axis.

4. The robot hand according to claim 3 , wherein the slide member has a first portion that is aligned with the slide axis and a second portion that is aligned with the first direction when the gripping portion is fully open.

5. The robot hand according to claim 2 , wherein the drive unit controls the drive force applied to the second slide unit in accordance with the position of the second slide unit in the first direction.

6. a second rotating member fixed to the base so as to rotate about a third axis extending in a third direction perpendicular to the first direction; 2. The robot hand according to claim 1, wherein the gripping mechanism comprises a chain member that connects the second sliding portion and the second rotating member and converts the rotational drive of the second rotating member into the sliding drive of the second sliding portion in the first direction.

7. The robot hand according to claim 1 or 6, wherein when the gripping portion opens from a completely closed state, the second sliding portion slides before the first sliding portion.

8. the base portion has an engaged portion, the first slide portion has an engaging portion that can engage with the engaged portion, When the engaging portion is engaged with the engaged portion, the engaging portion does not move from the engaged portion by a predetermined driving force, When the gripping portion is fully closed, the second sliding portion is slidable by the predetermined driving force, The robot hand according to claim 7 , wherein the engaging portion engages with the engaged portion.

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