End effector, robot system, control method of end effector, control method of robot system, manufacturing method of article, program, and recording medium

Abstract

To reduce expansion of a first finger part and a second finger part and achieve downsizing.SOLUTION: An end effector attached to a robot includes a first finger part (141) and a second finger part (142), at least one of which is movably supported so as to enable the finger parts to move close to or away from each other in a first direction (X) and the finger parts may sandwich a workpiece. The first finger part has: a first contact part (141a) which may contact with the workpiece (W) in the first direction (X); a butted part (141b) with which the workpiece is butted in a second direction (Y) intersecting with the first direction; and a first transmission part (141c) which transmits a force from the workpiece received in the second direction by the butted part. The second finger part includes: a second contact part (142a) which may contact with the workpiece in the first direction; and a first pressure receiving part (142b) which receives a pressure of the force from the workpiece received by the butted part through the first transmission part in the second direction in a state that the fingers are sandwiching the workpiece.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to an end effector, a robot system, a control method for an end effector, a control method for a robot system, a manufacturing method for an article, a program, and a recording medium. [Background technology]

[0002] For example, there is a demand for automating the task of gripping a pin-shaped workpiece with the fingers (so-called fingers) of a robot hand and inserting the workpiece into a desired position. For example, a conventional robot hand 1000 shown in FIG. 11(a) is configured such that a first finger 1141 can be driven by a first motor 1151 and a second finger 1142 can be driven by a second motor 1161. As shown in FIG. 11(b) and FIG. 11(c), the first finger 1141 and the second finger 1142 are configured to be able to grip a pin W at their tips. When such a robot hand 1000 is used to insert, for example, a pin W into a workpiece having a hole (not shown), a force is applied in the direction in which the first finger 1141 and the second finger 1142 spread. For this reason, it becomes necessary to generate a large driving force in the first motor 1151 and the second motor 1161 to suppress the spreading of the first finger portion 1141 and the second finger portion 1142, which causes a problem of increasing the size of the first motor 1151 and the second motor 1161. For this reason, for example, a proposal has been made to provide a palm portion between the multiple finger portions, and to receive the force from the workpiece with the palm portion when inserting the workpiece (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2012-139808 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, the above-mentioned Patent Document 1 has a problem in that the provision of a palm portion complicates the structure of the robot hand, leading to an increase in size. If the robot hand becomes large, for example, when the environment in which the pin insertion work is performed or the shape of the workpiece provides a small space, the robot hand may not be able to enter the work position and may not be able to insert the pin. For this reason, it is desirable to make the robot hand smaller.

[0005] Therefore, an object of the present invention is to provide an end effector, a robot system, a method for controlling an end effector, a method for controlling a robot system, a method for manufacturing an article, a program, and a recording medium that are capable of reducing the spread of the first finger portion and the second finger portion while also achieving miniaturization. [Means for solving the problem]

[0006] One aspect of the present invention is an end effector attached to a robot body of a robot system, comprising a main body portion, and first and second finger portions, at least one of which is supported for movement toward and away from the main body portion in a first direction and capable of clamping a workpiece, wherein the first finger portion has a first abutment portion capable of contacting the workpiece in the first direction, an abutment portion against which the workpiece is abutted in a second direction that intersects the first direction, and a first transmission portion that transmits a force received from the workpiece in the second direction at the abutment portion, and the second finger portion has a second abutment portion capable of contacting the workpiece in the first direction, and a first pressure receiving portion that, while clamping the workpiece, receives the force received from the workpiece at the abutment portion in the second direction via the first transmission portion.

[0007] One aspect of the present invention is an end effector attached to a robot body of a robot system, comprising a main body portion, and first and second finger portions, at least one of which is supported for movement toward and away from the main body portion in a first direction and capable of clamping a workpiece, wherein the first finger portion has a first surface capable of contacting the workpiece in the first direction, a second surface that protrudes beyond the first surface in the first direction and contacts the workpiece, and a third surface arranged opposite the second surface in a second direction that intersects the first direction, and the second finger portion has a fourth surface arranged opposite the first surface and capable of contacting the workpiece in the first direction, and a fifth surface that abuts the third surface in the second direction while clamping a workpiece.

[0008] One aspect of the present invention is a method for controlling an end effector attached to a robot body of a robot system having a controller, the end effector comprising: a main body; first finger portion and second finger portion, at least one of which is supported movably so as to move toward and away from the main body portion in a first direction and capable of gripping a workpiece; and the robot system having a controller, the first finger portion comprising a first abutment portion capable of contacting the workpiece in the first direction, an abutment portion against which the workpiece is abutted in a second direction that intersects with the first direction, and a first transmission portion that transmits a force received from the workpiece in the second direction at the abutment portion; the second finger portion has a second abutment portion capable of abutting against a workpiece in the first direction, and a first pressure receiving portion that receives a force from the workpiece in the second direction at the abutment portion in a state in which the workpiece is clamped, in the second direction via the first transmission portion, and the control unit is provided with a gripping process in which the workpiece is gripped by the first finger portion and the second finger portion, and a pressing process in which the control unit presses the workpiece gripped by the first finger portion and the second finger portion in the second direction via the abutment portion.

[0009] One aspect of the present invention relates to a control method for a robot system including a main body, an end effector including first and second finger portions, at least one of which is supported movably so as to move toward and away from the main body in a first direction and capable of gripping a workpiece, a robot body to which the end effector is attached and capable of moving the position and posture of the end effector, and a control unit that controls the robot body and the end effector, the first finger portion having a first abutment portion capable of contacting a workpiece in the first direction, an abutment portion against which a workpiece is abutted in a second direction that intersects with the first direction, and a control unit that controls the abutment portion. a first transmission portion that transmits a force received from a workpiece in the second direction at the abutment portion, the second finger portion having a second abutment portion that can abut against the workpiece in the first direction, and a first pressure receiving portion that receives a force received from the workpiece in the second direction at the abutment portion in the second direction via the transmission portion while clamping the workpiece, and the control unit is provided with a gripping process in which the control unit grips the workpiece with the first finger portion and the second finger portion, and a pressing process in which the control unit presses the workpiece gripped by the first finger portion and the second finger portion in the second direction via the abutment portion. Effect of the Invention

[0010] According to the present invention, it is possible to reduce the expansion of the first finger portion and the second finger portion while achieving miniaturization. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a diagram illustrating a robot system according to a first embodiment. [Diagram 2] FIG. 1 is a perspective view showing a robot hand according to a first embodiment. [Diagram 3] FIG. 2 is a bottom view showing the robot hand according to the first embodiment. [Figure 4] FIG. 2 is a side view showing the robot hand according to the first embodiment. [Diagram 5] 1A is a side view showing the configuration of a finger portion according to the first embodiment, and FIG. [Figure 6] 1A is a diagram showing a spring model of a first finger portion and a second finger portion according to the first embodiment, and FIG. 1B is a diagram showing the amount of deformation and generated force occurring in the first finger portion and the second finger portion. [Figure 7] 10(a) is a side view showing the configuration of a finger portion according to the second embodiment, and (b) is a side view showing the configuration of a finger portion according to a modified example of the second embodiment. [Figure 8] FIG. 13 is a side view showing the configuration of a finger portion according to the third embodiment. [Figure 9] FIG. 13 is a side view showing the configuration of a finger portion according to the fourth embodiment. [Figure 10] FIG. 13 is a side view showing a robot hand according to a fifth embodiment. [Figure 11] 1A is a side view showing a finger of a general robot hand, FIG. 1B is an enlarged side view showing a general finger, and FIG. 1C is a cross-sectional view taken along the line BB in FIG. 1B. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] First Embodiment A first embodiment for carrying out the present invention will be described below with reference to FIGS. 1 to 6. FIG.

[0013] [Outline of the robot system] First, a schematic configuration of a robot system according to the first embodiment will be described with reference to Fig. 1. Fig. 1 is a diagram showing the robot system according to the first embodiment.

[0014] 1, a robot system 1 installed in a factory or the like includes a robot device 10 that grasps and moves a workpiece, such as a metallic pin W, from a pin placement table (not shown) on which the workpiece is placed, and inserts the pin W into a hole 402H in a workpiece 402 to be assembled. The robot device 10 includes a base 2, a robot arm 10A as a robot or robot main body supported by the base 2, and a robot hand 100 as an end effector attached to the tip of the robot arm 10A. The robot system 1 also includes a control device 200 that controls the robot device 10, and a controller 300 is connectable to the control device 200.

[0015] The pin stand (not shown) is formed with a plurality of holes into which the pins W are inserted, and the pins W supplied as pre-operation parts are placed in these holes. The work 402 to be assembled is also formed with holes 402H into which the pins W as the work are inserted and fitted for assembly. That is, the robot device 10, which will be described later in detail, executes assembly control to perform the operation of assembling the pins W to the work 402 to be assembled, and the completed work 402 to be assembled is manufactured as an article by assembling a plurality of pins W to the work 402 to be assembled.

[0016] The robot arm 10A is a so-called six-axis articulated manipulator, and includes a pedestal 2, which is a base portion fixed to a workbench or a surface plate, and multiple links 11, 12, 13, 14, 15, and 16 that transmit displacement and force. The robot arm 10A also includes multiple joints J1, J2, J3, J4, J5, and J6 that connect the links 11 to 16 so that they can be turned or rotated. The link 16 disposed at the tip of the robot arm 10A is configured as a flange-shaped portion to which the robot hand 100 is attached.

[0017] The control device 200 is configured by a computer using a microprocessor element and the like, and can control the robot device 10. As shown in Fig. 1, the computer constituting the control device 200 is configured by, for example, a CPU 201 as a control unit, a ROM 202 storing programs for controlling each unit, a RAM 203, a communication interface (I / F in the figure) 204, and the like. Among these, the RAM 203 is used for temporarily storing data such as teaching points and control commands obtained by operating the controller 300. The programs for controlling each unit can be installed in the ROM 202 from a recording medium, and may be read from the recording medium into the ROM 202 via the communication interface 204.

[0018] The controller 300 may be an operating device such as a teaching pendant (TP), but may also be another computer device (PC or server) capable of editing a robot program. The controller 300 can be connected to the control device 200 via a wired or wireless communication connection means, and has a user interface function such as robot operation and status display. The CPU 201 receives, for example, teaching point data input by the controller 300 from the communication interface 204. In addition, the CPU 201 can generate trajectories of each axis (each link) of the robot device 10 based on the teaching point data input from the controller 300, and transmit the trajectories to the robot device 10 as control target values ​​via the communication interface 204. This allows the robot device 10 to operate the pin W, which is an operation target, by the robot hand 100 attached to the tip of the robot arm 10A.

[0019] [Structure of the robot hand] Next, a detailed configuration of the robot hand 100 will be described with reference to FIG. 2, FIG. 3, and FIG. 4. FIG. 2 is a perspective view showing the robot hand according to the first embodiment. FIG. 3 is a bottom view showing the robot hand according to the first embodiment. FIG. 4 is a side view showing the robot hand according to the first embodiment. The X direction as the first direction shown in FIG. 4 is the direction of the sliding movement of the finger portion 140, and is the gripping direction of the pin W. The Y direction as the second direction shown in FIG. 4 is a direction intersecting the X direction (direction perpendicular to the present embodiment) and is the insertion direction in which the pin W is inserted into the hole 402H. These X direction and Y direction are directions of the coordinate system in the robot hand 100, not the spatial coordinates of the robot system 1, that is, directions that change depending on the posture of the robot hand 100. In the present embodiment, the Y direction is the direction of the central axis of the robot hand 100 and also the direction of the optical axis of the camera 120, but is not limited to this.

[0020] As shown in FIG. 2, the robot hand 100 detachably attached to the tip of the robot arm 10A (see FIG. 1) is roughly configured to include a base 101 as a main body, a camera 120, and a finger portion 140 as a hand that is a work tool. The base 101 has an attachment portion 102 that is attached to a link 16 (see FIG. 1) of the robot arm 10A, and a camera 120 capable of taking an image is fixed and supported on the base 101. The camera 120 is moved so that the position of the robot hand 100 is a position in the sky at a predetermined distance from the workpiece 402 to be assembled by controlling the robot arm 10A, and the position of the camera 120 is controlled so that the focal position P is a hole 402H of the workpiece 402 to be assembled. This enables the camera 120 to take an image of the hole 402H that is the image-taking object, the work object, and the contact position. Similarly, when imaging a pin W placed on a pin stand (not shown) or its hole, the position is controlled so that the focal position P is the hole of the pin stand or the pin W placed therein. In this case, the imaging target is the hole of the pin stand or the pin W placed therein, and the work target or contact position is the pin W placed in the hole.

[0021] The base 101 is configured as a palm, and the first finger 141 and the second finger 142 constituting the finger 140 capable of performing an operation on a pin W, which is a workpiece, are supported on the base 101 so as to be movable toward and away from each other in the X direction in FIG. 4. The fingertip 141S of the first finger 141 and the fingertip 142S of the second finger 142 (see FIG. 5) can pinch the pin W between themselves, and can support the pin W by pinching and gripping it. The detailed configurations of the fingertip 141S and the fingertip 142S will be described later. The fingertip 141S of the first finger 141 and the fingertip 142S of the second finger 142 are located between the base 101 and the focal position P of the camera 120 while being within the field of view of the camera 120, as will be described later in detail. This allows the camera 120 to capture an image of an area farther away than the first finger portion 141 and the second finger portion 142, and to perform various controls based on the image.

[0022] Next, a structure for driving and moving the finger portion 140 will be described. As described above, the finger portion 140 has a first finger portion 141 and a second finger portion 142 as shown in Figs. 3 and 4, and is configured to be able to grip a pin W, which is a workpiece. The first finger portion 141 is fixed to a first slider 143 as a first finger support member, and the second finger portion 142 is fixed to a second slider 144 as a second finger support member. The base portion 101 includes a first guide portion 170 and a second guide portion 180 that movably guide the first slider 143 and the second slider 144, a first drive portion 150 that drives the first slider 143, and a second drive portion 160 that drives the second slider 144.

[0023] In detail, the first guide portion 170 as a slide portion has a first linear guide 171 as a guide member, and movable portions 172 and 173 slidably supported thereon. The second guide portion 180 as a slide portion has a second linear guide 181 as a guide member, and movable portions 182 and 183 slidably supported thereon. The first slider 143 is fixed to the movable portion 173 and the movable portion 183, and the second slider 144 is fixed to the movable portion 172 and the movable portion 182.

[0024] On the other hand, the first driving unit 150 is roughly configured to include a motor 151, a driving pulley 152, a belt 153, a driven pulley 154, a ball screw shaft 155, a ball nut 156, and an angle detection sensor 159. That is, the motor 151 outputs a driving rotation, and the driving pulley 152 fixed to the output shaft of the motor 151 is rotated. A belt 153 is stretched between the driving pulley 152 and the driven pulley 154, and the rotation of the driving pulley 152 is transmitted to the driven pulley 154. The driven pulley 154 is fixed to one end of a ball screw shaft 155, and by rotating the ball screw shaft 155, a ball nut 156 fixed to the first slider 143 is slid in the axial direction via a ball (not shown). Therefore, the first slider 143 linearly slides in the axial direction of the ball screw shaft 155 (in the direction along the first linear guide 171 and the second linear guide 181) while being guided by the first guide portion 170 and the second guide portion 180. Therefore, the first finger portion 141 is driven to move in the axial direction of the ball screw shaft 155 according to the rotation direction of the motor 151. For example, when the motor 151 is rotated forward, the first finger portion 141 moves to one side toward the right in the figure, and when the motor 151 is rotated backward, the first finger portion 141 moves to the other side toward the left in the figure. In addition, the rotation angle of the motor 151 is detected by an angle detection sensor 159 constituted by, for example, an encoder, and is output to the control device 200. Based on this, the CPU 201 determines the position of the first finger portion 141 by calculating it, and also controls the position of the first finger portion 141 by issuing a command to drive the motor 151 based on the position.

[0025] Similarly, the second driving unit 160 is roughly configured to include a motor 161, a driving pulley 162, a belt 163, a driven pulley 164, a ball screw shaft 165, a ball nut 166, and an angle detection sensor 169. That is, the motor 161 outputs a driving rotation, and the driving pulley 162 fixed to the output shaft of the motor 161 is rotated. A belt 163 is stretched between the driving pulley 162 and the driven pulley 164, and the rotation of the driving pulley 162 is transmitted to the driven pulley 164. The driven pulley 164 is fixed to one end of a ball screw shaft 165, and by rotating the ball screw shaft 165, a ball nut 166 fixed to the second slider 144 is slid in the axial direction via a ball (not shown). Therefore, the second slider 144 linearly slides in the axial direction of the ball screw shaft 165 while being guided by the first guide portion 170 and the second guide portion 180. Therefore, the second finger portion 142 is driven to move in the axial direction of the ball screw shaft 165 according to the rotation direction of the motor 161. For example, when the motor 161 is rotated forward, the second finger portion 142 moves to one side toward the left in the figure, and when the motor 161 is rotated backward, the second finger portion 142 moves to the other side toward the right in the figure. In addition, the rotation angle of the motor 161 is detected by an angle detection sensor 169 constituted by, for example, an encoder, and is output to the control device 200. Based on this, the CPU 201 determines the position of the second finger portion 142 by calculating it, and also controls the position of the second finger portion 142 by instructing the motor 161 to drive based on the position.

[0026] With the base 101 configured as described above, the first finger portion 141 and the second finger portion 142 are capable of moving independently in the X direction in Fig. 4 on the same first linear guide 171 and second linear guide 181. This reduces deviation in the relative positions of the first finger portion 141 and the second finger portion 142 in directions other than the movement direction when the first finger portion 141 and the second finger portion 142 move while gripping the pin W, making it easier to control the movement while gripping the pin W.

[0027] Furthermore, by placing the second linear guide 181 on the opposite side of the first linear guide 171 from the gripping position of the pin W, the moment force generated when placing the pin W8 can be supported by the two linear guides. This makes it possible to improve the durability of the first linear guide 171 and the second linear guide 181.

[0028] When the pin W is to be gripped between the first finger portion 141 and the second finger portion 142, first, the rotation angle of the motor 151 is detected by the angle detection sensor 159, and the rotation angle of the motor 161 is detected by the angle detection sensor 169. Then, based on these values, the CPU 201 controls the motor 151 and the motor 161 so that the first finger portion 141 and the second finger portion 142 are spaced apart from each other by the pin W and are positioned at the pin W. As a result, the pin W is gripped between the first finger portion 141 and the second finger portion 142.

[0029] In addition, the first finger portion 141 and the second finger portion 142 can move in the same direction in the X direction along the first linear guide 171 and the second linear guide 181 while maintaining the distance between them, that is, they can move while holding the pin W. That is, the first finger portion 141 and the second finger portion 142 can be moved from the position shown in FIG. 4 to the position shown in FIG. 5. That is, the first finger portion 141, the second finger portion 142, and the pin W can be in a retracted position retracted outside the field of view of the camera 120 (hereinafter simply referred to as "outside the field of view"). This moving outside the field of view of the camera 120 will be described later in the pin assembly operation. Note that when the first finger portion 141 and the second finger portion 142 are moved while holding the pin W, the distance between the first finger portion 141 and the second finger portion 142 is maintained. Therefore, based on the values ​​detected by angle detection sensor 159 and angle detection sensor 169, CPU 201 controls first finger portion 141 and second finger portion 142 so as to move their positions in a coordinated manner.

[0030] [Pin assembly operation] Next, the operation of acquiring the pin W by the robot device 10, inserting it into the workpiece 402 to be assembled and assembling it will be described. The CPU 201 of the control device 200 shown in FIG. 1 starts pin assembly control for inserting the pin W into the workpiece 402 to be assembled. Then, first, the robot arm 10A is driven to move the robot hand 100 to a position above a pin placement table (not shown) and above a position where the pin W is to be gripped. Next, the camera 120 (see FIGS. 2 to 4) attached to the robot hand 100 captures an image of the pin W and detects the position of the pin W. That is, the image captured by the camera 120 is compared with a predetermined target image, and the CPU 201 calculates the amount of deviation from the optimal position for gripping the pin W. Based on the calculated amount of deviation, posture data of the robot device 10 is generated, and the posture data is used to drive the robot arm 10A, and the gripping position of the finger portion 140 of the robot hand 100, which will be described later in detail, is aligned to the position of the pin W. Then, the fingers 140 of the robot hand 100 are driven to close, thereby clamping and gripping the pin W (gripping process).

[0031] Next, in order to insert the pin W held by the finger portion 140 into the workpiece 402 to be assembled, the robot hand 100 holding the pin W is moved by the robot arm 10A to above the hole 402H (work position) of the workpiece 402 to be assembled. Next, before the camera 120 captures an image, the finger portion 140 is slid and moved to retract so that the finger portion 140 and the pin W holding it are outside the field of view of the camera 120. Note that the finger portion 140 and the pin W may be within the field of view of the camera 120 as long as they can be retracted to the outside of the overlapping range where the finger portion 140 and the pin W overlap with the hole 402H of the workpiece 402 to be assembled. Here, the robot hand 100 is moved above the workpiece 402 to be assembled and then the finger portion 140 is retracted. However, the retraction operation of the finger portion 140 may be performed simultaneously with the movement of the robot hand 100. Furthermore, the retraction operation of the fingers 140 may be performed before the robot hand 100 is moved above the workpiece 402 to be assembled.

[0032] Next, the camera 120 captures an image of the hole 402H (work position) of the work 402 to be assembled, that is, the work position is detected. That is, the image captured by the camera 120 is compared with a predetermined target image, and the CPU 201 calculates the amount of deviation from the optimal position for inserting the pin W into the hole 402H of the work 402 to be assembled. Based on the calculated amount of deviation, posture data of the robot device 10 is generated, and the robot arm 10A is driven using the posture data to align the position of the robot hand 100 so that the pin W is inserted into the position for inserting the pin W with the finger 140. Then, the finger 140, which has been retracted in order to capture an image of the hole 402H of the work 402 to be assembled by the camera 120, is slid to return the finger 140 and the pin W to a position above the hole 402H. Thereafter, the robot arm 10A is torque-controlled to lower the pin W together with the robot hand 100, and the pin W held by the finger portions 140 is inserted into the hole 402H of the workpiece 402 while being pressed in the Y direction in Fig. 4 to perform assembly (pressing step). This completes the assembly operation of one pin W, and the process moves to the assembly operation of the next pin W. Then, when the assembly of all the pins W into the workpieces is completed as a task, the assembly control of the pins W by the robot device 10 ends, which means that one workpiece 402 is completed as an article and the manufacturing is completed.

[0033] [Shape of fingertip of finger part according to the first embodiment] Next, the shape of the fingertip of the finger portion 140 according to the first embodiment, i.e., the shape of the fingertip 141S of the first finger portion 141 and the fingertip 142S of the second finger portion 142, will be described with reference to Fig. 5. Fig. 5(a) is a side view showing the configuration of the finger portion according to the first embodiment. Fig. 5(b) is a cross-sectional view taken along the line AA in (a).

[0034] 5(a), the first fingertip 141S of the first finger 141 has a first gripping surface 141a as a first contact portion or a first surface, abutting surface 141b as a contact portion or a second surface, and a first transmitting surface 141c as a first transmitting portion or a third surface. Also, the first fingertip 141S of the first finger 141 has a first convex portion 141A that protrudes in a convex shape toward the second finger 142 side beyond the first gripping surface 141a.

[0035] In detail, the first gripping surface 141a is formed at the tip portion of the first fingertip 141S. The first gripping surface 141a is configured to be able to come into contact with the pin W from one side in the X direction by sliding at least one of the first finger 141 and the second finger 142 in a direction in which they approach each other, and holds the pin W together with a second gripping surface 142a of the second fingertip 142S described later. This makes it possible to grip the pin W.

[0036] In addition, the first convex portion 141A of the first fingertip portion 141S is inserted into a first concave portion 142A formed in a second fingertip portion 142S of the second fingertip portion 142 described later when at least one of the first finger portion 141 and the second finger portion 142 slides to grip the pin W. The first convex portion 141A of the first fingertip portion 141S has a surface on the side of the first gripping surface 141a in the Y direction formed as the abutment surface 141b, and a first transmission surface 141c is formed at a position facing the abutment surface 141b of the first convex portion 141A in the Y direction. In other words, the abutment surface 141b is formed toward the second finger portion 142 side in the X direction from the first gripping surface 141a so that the head portion of the gripped pin W is abutted against it. In addition, the first transmission surface 141c is formed to slide and abut against the first pressure receiving surface 142b described later when at least one of the first finger portion 141 and the second finger portion 142 slides to grip the pin W.

[0037] 5(b), the abutment surface 141b is formed so as to cover the entire area of ​​the head portion of the pin W held by the first finger portion 141 and the second finger portion 142 when viewed from the Y direction, and is particularly formed so as to overlap with the center Wct of the pin W when viewed from the Y direction. That is, in this embodiment, as will be described in detail later, the abutment surface 141b is configured to receive all (100%) of the reaction force generated in the Y direction from the held pin W. Note that, although an abutment surface may also be formed on the second finger portion 142 to receive part of the reaction force, even in this case, it is preferable that the abutment surface 141b is formed so as to overlap with the center of the pin W when viewed from the Y direction so that the first finger portion 141 receives most of the reaction force.

[0038] In this embodiment, the abutting surface 141b and the first transmitting surface 141c are formed so as to be perpendicular to the first gripping surface 141a, that is, so as to form an angle of 90 degrees. However, depending on the shape of the pin W, for example when the shape of the head portion of the pin W is inclined, the abutting surface 141b may be formed so as to be inclined in accordance with the shape of the pin W. In other words, the abutting surface 141b, the first transmitting surface 141c, and the first pressure receiving surface 142b described below may be in a direction that intersects with the first gripping surface 141a and the second gripping surface 142a described below.

[0039] On the other hand, second fingertip 142S of second finger 142 has second gripping surface 142a as a second contact portion or a fourth surface, and first pressure receiving surface 142b as a first pressure receiving portion or a fifth surface. Also, second fingertip 142S of second finger 142 has first recess 142A formed therein, which is recessed toward the opposite side to first finger 141 from second gripping surface 142a.

[0040] In detail, the second gripping surface 142a is formed at the tip portion of the second fingertip 142S, and is arranged to face and be parallel to the first gripping surface 141a of the first fingertip 141S of the first finger 141. The second gripping surface 142a is configured to be able to come into contact with the pin W from one side in the X direction by sliding at least one of the first finger 141 and the second finger 142 in a direction in which they approach each other, and holds the pin W together with the first gripping surface 141a of the first fingertip 141S. This makes it possible to grip the pin W.

[0041] In addition, the first convex portion 141A formed on the first fingertip portion 141S of the first finger portion 141 is inserted into the first concave portion 142A of the second fingertip portion 142S in a state in which at least one of the first finger portion 141 and the second finger portion 142 slides to grip the pin W. The first concave portion 142A of the second fingertip portion 142S is formed with a first pressure receiving surface 142b that slidably contacts the first transmission surface 141c on the opposite side of the second gripping surface 142a of the first concave portion 142A in the Y direction. That is, the first pressure receiving surface 142b is formed to contact the first pressure receiving surface 142b when the first convex portion 141A is pressed by the pin W gripped by the first finger portion 141 and the second finger portion 142. In addition, the first pressure receiving surface 142b has a slight clearance in the Y direction with respect to the first transmitting surface 141c so that the sliding first convex portion 141A and the first concave portion 142A do not collide with each other when the first convex portion 141A is not pressed by the pin W. The distance of this clearance in the Y direction is designed to be, for example, about 50 μm.

[0042] In the finger portion 140 configured as above, the pin W is clamped and held by the first gripping surface 141a and the second gripping surface 142a, and the pin W is inserted in the Y direction into the hole 402H of the workpiece 402 to be assembled. When the pin W is inserted into the hole 402H, a reaction force is generated in the Y direction according to the sliding resistance between the hole 402H and the pin W, and the reaction force is received by the abutment surface 141b against which the pin W abuts. Then, the reaction force from the pin W is transmitted to the first finger portion 141, and a part of the reaction force is transmitted to the first pressure receiving surface 142b of the second finger portion 142 via the first transmission surface 141c and received by the first pressure receiving surface 142b. As a result, the reaction force received from the pin W is distributed into a generated force F1 generated in the first finger portion 141 and a generated force F2 generated in the second finger portion 142, as shown in FIG. 5(a).

[0043] [Regarding the force generated in the finger portion 140] Next, the force generated in the finger portion 140 due to the reaction force when the pin W is inserted will be described with reference to Fig. 6. Fig. 6(a) is a diagram showing a spring model of the first finger portion and the second finger portion according to the first embodiment. Fig. 6(b) is a diagram showing the deformation amount and generated force generated in the first finger portion and the second finger portion.

[0044] 6(a), the spring constant of the first finger portion 141 is "k1", the spring constant of the second finger portion 142 is "k2", and the reaction force of the insertion force, which is the sliding resistance when the pin W is inserted, is "F". That is, when the pin W held by the fingers 140 is inserted into the hole 402H of the workpiece 402 to be assembled, the robot arm 10A moves the robot hand 100 to press the pin W in the Y direction. At this time, an insertion force is applied to the pin W from the robot hand 100, causing a sliding resistance between the hole 402H and the pin W, and a reaction force F of the insertion force is generated in response to the sliding resistance.

[0045] Here, when the pin W starts to be inserted, the pin W abuts against the abutment surface 141b of the first finger portion 141. However, since the above-mentioned clearance is provided between the first transmission surface 141c and the first pressure receiving surface 142b, only the first finger portion 141 receives the reaction force F of the insertion force while being deformed by the deformation amount Δx1 due to the spring constant k1. In other words, the distance of the clearance in the Y direction is the deformation amount Δx1. In other words, the state in which the first finger portion 141 is deformed by the deformation amount Δx1 is a state in which the above-mentioned clearance disappears and the first finger portion 141 is elastically deformed to the position A where the first transmission surface 141c and the first pressure receiving surface 142b abut. In this state, as shown in FIG. 6(b), a generated force FA is generated in the first finger portion 141 as the generated force F1 of the first finger portion 141.

[0046] Furthermore, when the insertion force of the pin W increases and the reaction force F increases, a part of the reaction force F generated at the abutment surface 141b of the first finger portion 141 is transmitted from the first transmission surface 141c to the first pressure receiving surface 142b of the second finger portion 142 via the convex portion 141A. As a result, the first finger portion 141 is deformed by a deformation amount Δx1+Δx2 due to the spring constant k1, and the second finger portion 142 is deformed by a deformation amount Δx2 due to the spring constant k2 while receiving the reaction force F of the insertion force. Then, when the first finger portion 141 and the second finger portion 142 are elastically deformed to the position B, the generated force FB is generated in the first finger portion 141 and the second finger portion 142, and the generated force F1 of the first finger portion 141 and the generated force F2 of the second finger portion 142 become equal.

[0047] The relationship between the spring constant k1 of the first finger portion 141 and the spring constant k2 of the second finger portion 142 that achieves this state is set as shown in the following formula. k1 / k2=Δx2 / (Δx1+Δx2) (Formula 1) By setting the rigidity of the first finger portion 141 and the second finger portion 142 so as to satisfy the relationship shown in Equation 1, the reaction force F of the insertion force when inserting the pin W into the hole portion 402H of the assembly workpiece 402 can be evenly distributed to the first finger portion 141 and the second finger portion 142.

[0048] [Examples of finger and robot hand sizes] An example of the size of the finger portion 140 and the robot hand 100 of the first embodiment described above will be described. The first finger portion 141 and the second finger portion 142 have a length of 120 mm, a width of 10 mm, and a plate thickness of 4 mm. The material of the first finger portion 141 and the second finger portion 142 is SUS303. The size of the pin W is an outer diameter of 3 mm and a length of 6 mm.

[0049] For example, in the shape of the fingers shown in FIG. 11(a) and FIG. 11(b), when a reaction force of 200 N occurs against the insertion force of the pin W, a gripping force of 60 N is required, and the size (volume) of the robot hand 1000 is 1,805,000 mm 3 On the other hand, in the shape of the finger portion 140 according to the first embodiment (see FIG. 5(a)), when a reaction force of 200 N occurs against the insertion force of the pin W, a gripping force of 20 N is required, and the size (volume) of the robot hand 100 is 1,054,620 mm 3 As described above, the size (volume) of the robot hand 100 could be reduced by 41%, and the robot hand 100 could be made more compact.

[0050] [Summary of the first embodiment] As described above, in the first embodiment, the reaction force of the insertion force when inserting the pin W is received only by the abutting surface 141b of the first finger portion 141, so that the first finger portion 141 and the second finger portion 142 can be reduced from bending and escaping. In other words, the reaction force received in the direction in which the first finger portion 141 and the second finger portion 142 spread (see FIG. 11(b)) can be reduced. This makes it unnecessary to increase the driving force of the first motor 151 and the second motor 161 so that the first finger portion 141 and the second finger portion 142 do not spread, and the first motor 151 and the second motor 161 can be prevented from becoming large. In other words, the first finger portion 141 and the second finger portion 142 according to this embodiment can receive a large reaction force F of the insertion force with a small gripping force.

[0051] Furthermore, the first pressure receiving surface 142b of the second finger portion 142 receives part of the reaction force of the insertion force of the pin W via the first transmission surface 141c of the first finger portion 141, so that the reaction force F of the insertion force occurring in the first finger portion 141 and the second finger portion 142 can be dispersed. This makes it possible to reduce the force supporting the first finger portion 141 compared to a case where the reaction force F of the insertion force is received only by the abutment surface 141b, that is, the reaction force F of the insertion force occurs only in the first finger portion 141. This makes it possible to reduce the force occurring in the first guide portion 170 and the second guide portion 180 that guide the first finger portion 141 so as to be able to slide, and prevents the first guide portion 170 and the second guide portion 180 from becoming large in size.

[0052] In this way, the first motor 151 and the second motor 161 can be prevented from becoming large, and the first guide portion 170 and the second guide portion 180 can be prevented from becoming large, so that the robot hand 100 can be made smaller while reducing the spreading of the first finger portion 141 and the second finger portion 142.

[0053] Also, first convex portion 141A of first finger portion 141 and first concave portion 142A of second finger portion 142 are formed to mesh with each other in a state where pin W is gripped. Therefore, a structure capable of transmitting a part of the force generated in first finger portion 141 to second finger portion 142 can be achieved without increasing the distance in the X direction between first finger portion 141 and second finger portion 142, that is, the finger portion 140 can be prevented from becoming thicker.

[0054] <Second embodiment> Next, a second embodiment, which is a partial modification of the first embodiment, will be described with reference to Fig. 7. Fig. 7(a) is a side view showing the configuration of a finger portion according to the second embodiment. Fig. 7(b) is a side view showing the configuration of a finger portion according to a modification of the second embodiment.

[0055] As shown in FIG. 7(a), the finger portion 140 of the robot hand 100 according to the second embodiment has a first chamfered portion 142c that is chamfered at the opening of the first concave portion 142A of the second finger portion 142 on the side facing the first convex portion 141A. That is, the tip of the first pressure receiving surface 142b of the second finger portion 142 on the side of the first finger portion 141 in the X direction is chamfered as the first chamfered portion 142c. This prevents the tip of the first convex portion 141A from colliding (interfering) with the opening of the first concave portion 142A when the first finger portion 141 and the second finger portion 142 slide and move closer to each other in the X direction and the first convex portion 141A is inserted into the first concave portion 142A. Therefore, when gripping the pin W, the first finger portion 141 and the second finger portion 142 can be smoothly brought closer to each other to enable gripping of the pin W.

[0056] As shown in FIG. 7(b), as a modified example of the second embodiment, the first convex portion 141A of the first finger portion 141 may have a second chamfered portion 141d that is chamfered at the tip portion on the side facing the first concave portion 142A. That is, the tip portion of the first transmission surface 141c of the first finger portion 141 on the second finger portion 142 side in the X direction is chamfered as the second chamfered portion 141d. This also prevents the tip portion of the first convex portion 141A from colliding with the opening of the first concave portion 142A when the first finger portion 141 and the second finger portion 142 slide and move closer to each other in the X direction and the first convex portion 141A is inserted into the first concave portion 142A. Therefore, when gripping the pin W, the first finger portion 141 and the second finger portion 142 can be smoothly brought closer to each other to enable gripping of the pin W.

[0057] Other configurations, operations, and effects of the second embodiment are similar to those of the first embodiment, and therefore description thereof will be omitted.

[0058] <Third embodiment> Next, a third embodiment, which is a partial modification of the first embodiment, will be described with reference to Fig. 8. Fig. 8 is a side view showing the configuration of a finger portion according to the third embodiment.

[0059] As shown in FIG. 8, the finger portion 140 of the robot hand 100 according to the third embodiment has a first transmission surface 141c of the first finger portion 141 inclined and a first pressure receiving surface 142b of the second finger portion 142 inclined. That is, in the first finger portion 141, the first transmission surface 141c of the first convex portion 141A is inclined with respect to the Y direction (with respect to a plane parallel to the X direction) so that the side facing the first concave portion 142A, that is, the tip side, has a tapered shape. Also, in the second finger portion 142, the first pressure receiving surface 142b of the first concave portion 142A is inclined with respect to the Y direction (with respect to a plane parallel to the X direction) so that the side facing the first convex portion 141A, that is, the opening side, has a widening shape. The inclination angles of the first transmission surface 141c and the first pressure receiving surface 142b are substantially the same with respect to the Y direction.

[0060] In this manner, the first transmission surface 141c of the first finger portion 141 and the first pressure receiving surface 142b of the second finger portion 142 are inclined. This prevents the tip of the first convex portion 141A from colliding (interfering) with the opening of the first concave portion 142A when the first finger portion 141 and the second finger portion 142 slide and move closer to each other in the X direction and the first convex portion 141A is inserted into the first concave portion 142A. In addition, when the first finger portion 141 and the second finger portion 142 are gradually brought closer to each other to grip the pin W, the first transmission surface 141c and the first pressure receiving surface 142b gradually approach each other, which enables the pin W to be gripped smoothly.

[0061] When the pin W is gripped, the first transmission surface 141c and the first pressure receiving surface 142b may come into contact with each other; however, taking into account component tolerances, it is preferable to design them so that there is a clearance between them similar to that in the first embodiment.

[0062] Other configurations, operations, and effects of the third embodiment are similar to those of the first embodiment, and therefore description thereof will be omitted.

[0063] <Fourth embodiment> Next, a fourth embodiment, which is a partial modification of the first embodiment, will be described with reference to Fig. 9. Fig. 9 is a side view showing the configuration of a finger portion according to the fourth embodiment.

[0064] 9, the finger portion 140 of the robot hand 100 according to the fourth embodiment is provided with a second transmission surface 141f as a second transmission portion or a sixth surface in addition to the first transmission surface 141c at a first fingertip portion 141S of a first finger portion 141. Furthermore, a second pressure receiving surface 142e as a second pressure receiving portion or a seventh surface is provided at a second fingertip portion 142S of a second finger portion 142 in addition to the first pressure receiving surface 142b.

[0065] That is, the first finger portion 141 has a first transmission surface 141c that transmits the force received in the Y direction from the pin W at the abutment surface 141b, and also has a second transmission surface 141e that transmits the force received in the Y direction from the pin W at the abutment surface 141b. The second finger portion 142 has a first pressure receiving surface 142b that receives the force received in the Y direction from the pin W at the abutment surface 141b in the Y direction via the first transmission surface 141c when the pin W is clamped. The second finger portion 142 has a second pressure receiving surface 142d that receives the force received in the Y direction from the pin W at the abutment surface 141b in the Y direction via the second transmission surface 141e when the pin W is clamped.

[0066] In detail, the first finger portion 141 has a second convex portion 141B protruding in a convex shape from the first gripping surface 141a on the base side of the above-mentioned first convex portion 141A, and the above-mentioned second transmission surface 141e is formed on the second convex portion 141B. Also, the second finger portion 142 has a concave second recess 142B on the base side of the above-mentioned first recess 142A so as to be arranged opposite the second convex portion 141B. That is, the second recess 142B is arranged opposite the second convex portion 141B in the X direction with the first finger portion 141 and the second finger portion 142 separated from each other, and the second convex portion 141B is inserted in a state where the pin W is sandwiched. And the above-mentioned second pressure receiving surface 142d is formed on the second recess 142B.

[0067] With this configuration, a part of the reaction force F of the insertion force generated on the abutting surface 141b of the pin W can be transmitted from the first finger portion 141 to the second finger portion 142 at two points, namely, the first transmission surface 141c and the first pressure receiving surface 142b, and the second transmission surface 141e and the second pressure receiving surface 142d. As a result, even if, for example, the first transmission surface 141c and the first pressure receiving surface 142b are worn and only the second transmission surface 141e and the second pressure receiving surface 142d are in contact, a part of the reaction force F of the insertion force can be transmitted from the first finger portion 141 to the second finger portion 142. Conversely, even if, for example, the second transmission surface 141e and the second pressure receiving surface 142d are worn and only the first transmission surface 141c and the first pressure receiving surface 142b are in contact, a part of the reaction force F of the insertion force can be transmitted from the first finger portion 141 to the second finger portion 142. Therefore, the durability of the finger portion 140 can be improved.

[0068] In the fourth embodiment, the tip of the first convex portion 141A, the tip of the second convex portion 141B, the opening of the first recess 142A, and the opening of the second recess 142B may be provided with a chamfered portion as described in the second embodiment. Furthermore, the first transmission surface 141c, the second transmission surface 141e, the first pressure receiving surface 142b, and the second pressure receiving surface 142d in the fourth embodiment may be inclined with respect to the Y direction as described in the third embodiment.

[0069] Moreover, other configurations, operations, and effects of the fourth embodiment are similar to those of the first embodiment, and therefore description thereof will be omitted.

[0070] <Fifth embodiment> Next, a fifth embodiment, which is a partial modification of the first embodiment, will be described with reference to Fig. 10. Fig. 10 is a side view showing a robot hand according to the fifth embodiment.

[0071] 10, the robot hand 500 according to the fifth embodiment is roughly configured to include a base 501 as a main body, a first parallel link mechanism 570 and a second parallel link mechanism 580 as slide parts, and a finger unit 140. The base 501 has an attachment part 502 that is attached to a link 16 (see FIG. 1) of the robot arm 10A. The first parallel link mechanism 570 and the second parallel link mechanism 580 are attached to the base 501, and the first finger unit 141 is attached to the first parallel link mechanism 570, and the second finger unit 142 is attached to the second parallel link mechanism 580.

[0072] In detail, the first parallel link mechanism 570 has a first fixed part 571, two links 572 and 573, and a first movable part 543 as a first finger support member, and is configured as a parallel link mechanism having a so-called rectangular (parallelogram) pantograph configuration. The first fixed part 571 is fixedly attached to the base part 501, and the first finger part 141 is fixedly attached to the movable part 543. The link 572 is fixed to a first drive shaft 555 as a first drive part that is drivingly connected to a motor (not shown) that drives the link 572 to rotate via a drive system (not shown). In the first parallel link mechanism 570 as described above, the first drive shaft 555 is rotated by driving a motor (not shown), and the link 572 is rotated to control the inclination angle, so that the first movable part 543 is moved in parallel in the X direction relative to the first fixed part 571 and slid.

[0073] Similarly, the second parallel link mechanism 580 has a second fixed part 581, two links 582 and 583, and a second movable part 544 as a second finger support member, and is configured as a parallel link mechanism having a so-called rectangular (parallelogram) pantograph configuration. The second fixed part 581 is fixedly attached to the base part 501, and the second finger part 142 is fixedly attached to the second movable part 544. The link 582 is fixed to a second drive shaft 565 as a second drive part that is drivingly connected to a motor (not shown) that drives the link 582 to rotate via a drive system (not shown). In the second parallel link mechanism 580 as described above, the second drive shaft 565 is rotated by driving a motor (not shown), and the link 582 is rotated to control the inclination angle, so that the second movable part 544 is moved in parallel in the X direction relative to the second fixed part 581 and slid.

[0074] In the robot hand 500 according to the fifth embodiment configured in this manner, the first finger portion 141 and the second finger portion 142 are moved linearly while maintaining a parallel posture with respect to the base portion 501. This allows the distance in the X direction between the first finger portion 141 and the second finger portion 142 to be changed, and the first finger portion 141 and the second finger portion 142 to be opened and closed, and the pin W can be grasped by the first finger portion 141 and the second finger portion 142.

[0075] The configurations of the first finger portion 141 and the second finger portion 142 of the robot hand 500 in the fifth embodiment are similar to those in the first embodiment, and therefore the description thereof will be omitted. Also, the configurations of the first finger portion 141 and the second finger portion 142 of the robot hand 500 may be the configurations described in the second to fourth embodiments.

[0076] Moreover, other configurations, operations, and effects of the fifth embodiment are similar to those of the first embodiment, and therefore description thereof will be omitted.

[0077] <Possibilities for other embodiments> In the above-described first to fifth embodiments, the abutment surface 141b of the first finger portion 141 is formed to overlap with the center of the pin W as the workpiece when viewed from the Y direction. However, the present invention is not limited to this, and the abutment surface 141b may not necessarily be formed so that the center of the pin W abuts against the abutment surface 141b, for example, the abutment surface 141b may be formed in a hollow shape and abut against the periphery of the pin W. In short, as long as the majority of the area of ​​the workpiece is configured to abut against the abutment surface when viewed from the Y direction, the reaction force of the insertion force of the workpiece can be received.

[0078] In the first to fifth embodiments, the first finger portion 141 is formed with the first convex portion 141A and the second convex portion 141B as convex portions, and the second finger portion 142 is formed with the first concave portion 142A and the second concave portion 142B as concave portions, which are abutted in the Y direction to transmit a force. However, this is not limited to this, and as long as a transmission surface that transmits a force is formed in the first finger portion 141 and a pressure receiving surface that receives a force from the transmission surface is formed in the second finger portion 142, the shape is not limited to a convex portion or a concave portion. For example, the first finger portion 141 may be bent so that the abutment surface and the transmission surface do not overlap when viewed from the Y direction. Similarly, the second finger portion 142 may be bent so that the abutment surface and the pressure receiving surface do not overlap when viewed from the Y direction.

[0079] In the first to fifth embodiments, each surface of the finger portion 140 (first gripping surface 141a, abutting surface 141b, first transmitting surface 141c, second transmitting surface 141e, second gripping surface 142a, first pressure receiving surface 142b, and second pressure receiving surface 142d) is described as being flat. However, the present invention is not limited to this, and the surfaces may have any shape, such as a curved surface or a stepped surface. Furthermore, the surfaces may be provided with projections and recesses or have a sheet attached thereto.

[0080] In the first to fifth embodiments, the camera 120 is attached to and supported by the base 101 of the robot hand 100 (the base 501 of the robot hand 500), but this is not limiting. The camera 120 may be attached to the robot arm 10A, or may be installed at a fixed point (for example, on the ceiling) of the installation location where the robot system 1 is installed.

[0081] In the first to fifth embodiments, the robot hand 100 is described as sliding the first finger portion 141 and the second finger portion 142, but the present invention is not limited to this configuration. For example, the robot hand 100 may have three or more fingers, and the fingers may move on an arc instead of on a straight line.

[0082] In the first to fourth embodiments, the first guide portion 170 and the second guide portion 180 are described so that the first finger portion 141 and the second finger portion 142 slide, but the present invention is not limited to this, and may have one guide portion or three or more guide portions. Of course, having a plurality of guide portions stabilizes the movement of the first finger portion 141 and the second finger portion 142 and also stabilizes the gripping of the workpiece, so it is preferable to have two or more guide portions. In addition, the first finger portion 141 and the second finger portion 142 are driven by the motors 151 and 161, but the present invention is not limited to this, and may be driven by, for example, a solenoid or hydraulic pressure.

[0083] In addition, the present disclosure is not limited to the above-described embodiments, and the embodiments can be modified in many ways within the technical concept of the present disclosure. For example, at least two of the above-described embodiments and modifications may be combined. In addition, the effects described in the present embodiment are merely a list of the most preferable effects resulting from the embodiments of the present disclosure, and the effects of the embodiments of the present disclosure are not limited to those described in the present embodiment.

[0084] In the above-mentioned first to fifth embodiments, the robot is a vertically articulated robot, but the present invention is not limited to this. The robot may be, for example, a horizontally articulated robot, a parallel link robot, or an orthogonal robot. The above-mentioned embodiments are applicable to a machine that can automatically perform the actions of expanding and contracting, bending and stretching, moving up and down, moving left and right, or turning, or a combination of these actions, based on information in a storage device provided in the control device.

[0085] The present disclosure can also be realized by a process in which a program for implementing one or more functions of the above-described embodiments is supplied to a system or device via a network or a storage medium, and one or more processors in a computer of the system or device read and execute the program. It can also be realized by a circuit (e.g., ASIC) that implements one or more functions.

[0086] <Disclosure of the Present Embodiment> [Configuration 1] In an end effector attached to a robot, a first finger portion and a second finger portion, at least one of which is supported so as to be movable toward and away from each other in a first direction and capable of clamping a workpiece; the first finger portion has a first abutment portion capable of abutting against a workpiece in the first direction, an abutment portion against which the workpiece is abutted in a second direction that intersects with the first direction, and a first transmission portion that transmits a force received from the workpiece in the second direction at the abutment portion; The second finger portion has a second contact portion capable of contacting the workpiece in the first direction, and a first pressure receiving portion that receives a force from the workpiece at the abutting portion in the second direction via the first transmission portion while the workpiece is being clamped. An end effector characterized by: [Configuration 2] The abutting portion is formed so as to overlap with the center of the workpiece gripped by the first finger portion and the second finger portion when viewed from the second direction. 2. The end effector of configuration 1. [Configuration 3] the first finger portion has a protrusion in which the abutting portion and the first transmission portion are formed and which protrudes in a convex shape from the first contact portion; The second finger portion has the first pressure receiving portion formed thereon, is disposed opposite the convex portion in the first direction in a spaced-apart state, and has a concave recess into which the convex portion is inserted when the workpiece is clamped. 3. An end effector according to configuration 1 or 2. [Configuration 4] The recess has a first chamfered portion that is chamfered at an opening on a side facing the protrusion. 4. The end effector of configuration 3. [Configuration 5] The protrusion has a second chamfered portion that is chamfered at a tip end on a side facing the recess. 5. The end effector according to configuration 3 or 4. [Configuration 6] the first transmission portion is formed to be inclined with respect to the second direction so that the convex portion has a tapered shape on a side facing the concave portion, The recess is formed so that the first pressure-receiving portion is inclined with respect to the second direction so that the side facing the protrusion is wider. 4. The end effector of configuration 3. [Configuration 7] the first finger portion has, as the first contact portion, a first surface capable of contacting a workpiece in the first direction, a second surface as the butting portion, which protrudes in the first direction beyond the first surface and contacts the workpiece, and a third surface as the first transmission portion, which is disposed opposite the second surface in the second direction; The second finger portion has a fourth surface as the second contact portion, which is disposed opposite to the first surface and can contact the workpiece in the first direction, and a fifth surface as the first pressure receiving portion, which contacts the third surface in the second direction while clamping the workpiece. 7. An end effector according to any one of configurations 1 to 6. [Configuration 8] The first finger portion has a second transmission portion that transmits the force received from the workpiece in the second direction at the abutting portion, The second finger portion has a second pressure receiving portion that receives a force from the workpiece in the second direction at the abutting portion in a state where the workpiece is clamped, in the second direction via the second transmission portion. 3. An end effector according to configuration 1 or 2. [Configuration 9] the first finger portion has a first convex portion in which the abutting portion and the first transmission portion are formed and which protrudes in a convex shape from the first contact portion, and a second convex portion in which the second transmission portion is formed and which protrudes in a convex shape from the first contact portion, The second finger portion has a first concave portion in which the first pressure receiving portion is formed, the first convex portion is disposed facing the first convex portion in the first direction in a spaced-apart state, and the first convex portion is inserted into the first convex portion when the workpiece is clamped; and the second pressure receiving portion is formed in the second concave portion, the second convex portion is disposed facing the second convex portion in the first direction in a spaced-apart state, and the second convex portion is inserted into the second concave portion when the workpiece is clamped. 9. The end effector of embodiment 8. [Configuration 10] The first finger portion has, as the first contact portion, a first surface capable of contacting a workpiece in the first direction, a second surface as the butting portion that protrudes in the first direction beyond the first surface and contacts a workpiece, a third surface as the first transmission portion and disposed opposite the second surface in the second direction, and a sixth surface as the second transmission portion and disposed opposite the second surface in the second direction, The second finger portion has, as the second abutment portion, a fourth surface that is disposed opposite to the first surface and can abut against the workpiece in the first direction, a fifth surface that abuts against the third surface in the second direction while the workpiece is clamped as the first pressure receiving portion, and a seventh surface that abuts against the sixth surface in the second direction while the workpiece is clamped as the second pressure receiving portion. 10. The end effector according to claim 8 or 9. [Configuration 11] In an end effector attached to a robot, a first finger portion and a second finger portion, at least one of which is supported so as to be movable toward and away from each other in a first direction and capable of clamping a workpiece; The first finger portion has a first surface capable of contacting a workpiece in the first direction, a second surface protruding in the first direction beyond the first surface and contacting the workpiece, and a third surface disposed opposite the second surface in a second direction that intersects with the first direction, The second finger portion has a fourth surface that is disposed opposite to the first surface and is capable of contacting the workpiece in the first direction, and a fifth surface that contacts the third surface in the second direction while clamping the workpiece. An end effector characterized by: [Configuration 12] The body portion includes: a slide portion that supports the first finger portion and the second finger portion so as to be slidable; a first driving unit that drives the first finger unit to slide on the sliding unit; and a second driving unit that can be driven independently of the first finger unit and drives the second finger unit to slide on the sliding unit. 12. An end effector according to any one of configurations 1 to 11. [Configuration 13] The slide portion includes a guide member, a first finger support member that is guided in a straight line by the guide member and supports the first finger portion, and a second finger support member that is guided in a straight line by the guide member and supports the second finger portion. 13. The end effector of configuration 12. [Configuration 14] The slide portion has a first parallel link mechanism that translates a first finger support member that supports the first finger portion, and a second parallel link mechanism that translates a second finger support member that supports the second finger portion. 13. The end effector of configuration 12. [Configuration 15] An end effector according to any one of configurations 1 to 14; a robot to which the end effector is attached and capable of changing the position and orientation of the end effector; A control unit that controls the robot and the end effector. A robot system comprising: [Method 16] A method for controlling an end effector attached to a robot of a robot system having a controller, the method comprising: first finger portion and second finger portion, at least one of which is supported movably so as to move toward and away from each other in a first direction and capable of gripping a workpiece; the first finger portion has a first abutment portion capable of abutting against a workpiece in the first direction, an abutment portion against which the workpiece is abutted in a second direction that intersects with the first direction, and a first transmission portion that transmits a force received from the workpiece in the second direction at the abutment portion; the second finger portion has a second abutment portion capable of abutting against a workpiece in the first direction, and a first pressure receiving portion that receives a force from the workpiece in the second direction at the abutting portion in a state in which the workpiece is clamped, in the second direction via the first transmission portion; a gripping step in which the control unit grips a workpiece with the first finger portion and the second finger portion; The control unit includes a pressing step of pressing the workpiece gripped by the first finger portion and the second finger portion in the second direction via the abutting portion. A method for controlling an end effector comprising the steps of: [Method 17] an end effector including a first finger portion and a second finger portion, at least one of which is supported so as to be movable toward and away from each other in a first direction and capable of gripping a workpiece; a robot to which the end effector is attached and capable of changing the position and orientation of the end effector; a control unit that controls the robot and the end effector, the first finger portion has a first abutment portion capable of abutting against a workpiece in the first direction, an abutment portion against which the workpiece is abutted in a second direction that intersects with the first direction, and a first transmission portion that transmits a force received from the workpiece in the second direction at the abutment portion; the second finger portion has a second abutment portion capable of abutting against a workpiece in the first direction, and a first pressure receiving portion that receives a force from the workpiece in the second direction at the abutting portion in a state in which the workpiece is clamped, in the second direction via the transmission portion; a gripping step in which the control unit grips a workpiece with the first finger portion and the second finger portion; The control unit includes a pressing step of pressing the workpiece gripped by the first finger portion and the second finger portion in the second direction via the abutting portion. A method for controlling a robot system comprising: [Method 18] A method for manufacturing an article, comprising the steps of: manufacturing an article using the robot system according to aspect 15. [Configuration 19] A program for causing a computer to execute the control method for a robot system according to Method 17. [Configuration 20] A computer-readable recording medium storing the program according to configuration 19. [Explanation of symbols]

[0087] 1...Robot system / 10A...Robot arm (robot) / 100...Robot hand (end effector) / 101...Base (main body) / 141...First finger part / 141A...First convex part (convex part) / 141B...Second convex part / 141a...First gripping surface (first contact part, first surface) / 141b...Abutting surface (butting part, second surface) / 141c...First transmission surface ( 142a...2nd gripping surface (second abutment portion, 4th surface) / 142b...1st pressure receiving surface (first pressure receiving portion, 5th surface) / 142c...1st chamfered portion / 142d...2nd transmission surface (second pressure receiving portion, 7th surface) / 143...first slider (first finger support member) / 144...second slider (second finger support member) / 150...first drive section / 160...second drive section / 170...first guide section (slide section) / 171...first linear guide (guide member) / 180...second guide section (slide section) / 181...second linear guide (guide member) / 201...CPU (control section) / 543...first movable section (first finger support member) / 544...second movable section (second finger support member) / 555...first drive shaft (first drive section) / 565...second drive shaft (second drive section) / 570...first parallel link mechanism (slide section) / 580...second parallel link mechanism (slide section) / W...pin (workpiece) / Wct...center of pin (center of workpiece) / X...first direction / Y...second direction

Claims

1. In an end effector attached to a robot, a first finger portion and a second finger portion, at least one of which is supported so as to be movable toward and away from each other in a first direction and capable of clamping a workpiece; the first finger portion has a first abutment portion capable of abutting against a workpiece in the first direction, a butting portion against which the workpiece is butted in a second direction that intersects with the first direction, and a first transmission portion that transmits a force received from the workpiece in the second direction at the butting portion; The second finger portion has a second abutting portion capable of abutting against the workpiece in the first direction, and a first pressure receiving portion that receives a force from the workpiece at the abutting portion in the second direction via the first transmission portion while the workpiece is being clamped. An end effector characterized by:

2. The abutting portion is formed so as to overlap with the center of the workpiece gripped by the first finger portion and the second finger portion when viewed from the second direction. The end effector of claim 1 .

3. the first finger portion has the abutting portion and the first transmission portion formed thereon, and has a convex portion that protrudes in a convex shape from the first contact portion, The second finger portion has the first pressure receiving portion formed thereon, is disposed opposite the convex portion in the first direction in a spaced-apart state, and has a concave recess into which the convex portion is inserted in a state where the workpiece is clamped. The end effector of claim 1 .

4. The recess has a first chamfered portion that is chamfered at an opening on a side facing the protrusion. The end effector of claim 3 .

5. The protrusion has a second chamfered portion that is chamfered at a tip end on a side facing the recess. The end effector of claim 3 .

6. the first transmission portion is formed to be inclined with respect to the second direction so that the protrusion has a tapered shape on a side facing the recess, The recess is formed so that the first pressure-receiving portion is inclined with respect to the second direction so that the side facing the protrusion has a wider shape. The end effector of claim 3 .

7. The first finger portion has, as the first contact portion, a first surface capable of contacting a workpiece in the first direction, as the butting portion, a second surface protruding in the first direction beyond the first surface and contacting the workpiece, and as the first transmission portion, a third surface disposed opposite the second surface in the second direction, The second finger portion has a fourth surface as the second contact portion, which is disposed opposite to the first surface and can contact the workpiece in the first direction, and a fifth surface as the first pressure receiving portion, which contacts the third surface in the second direction while clamping the workpiece. The end effector of claim 1 .

8. The first finger portion has a second transmission portion that transmits a force received from the workpiece in the second direction at the abutting portion, The second finger portion has a second pressure receiving portion that receives a force from the workpiece in the second direction at the abutting portion in a state where the workpiece is clamped, in the second direction via the second transmission portion. The end effector of claim 1 .

9. the first finger portion has a first convex portion in which the abutting portion and the first transmission portion are formed and which protrudes in a convex shape from the first contact portion, and a second convex portion in which the second transmission portion is formed and which protrudes in a convex shape from the first contact portion, The second finger portion has a first concave portion in which the first pressure receiving portion is formed, the first pressure receiving portion is disposed opposite the first convex portion in the first direction in a spaced-apart state, and the first convex portion is inserted into the first concave portion in a state where the workpiece is clamped, and a second concave portion in which the second pressure receiving portion is formed, the second pressure receiving portion is disposed opposite the second convex portion in the first direction in a spaced-apart state, and the second convex portion is inserted into the second concave portion in a state where the workpiece is clamped. The end effector of claim 8 .

10. The first finger portion has, as the first contact portion, a first surface capable of contacting a workpiece in the first direction, a second surface as the butting portion that protrudes in the first direction beyond the first surface and contacts the workpiece, a third surface as the first transmission portion and disposed opposite the second surface in the second direction, and a sixth surface as the second transmission portion and disposed opposite the second surface in the second direction, The second finger portion has, as the second abutment portion, a fourth surface that is disposed opposite to the first surface and can abut against the workpiece in the first direction, a fifth surface that serves as the first pressure receiving portion and abuts against the third surface in the second direction with the workpiece clamped, and a seventh surface that serves as the second pressure receiving portion and abuts against the sixth surface in the second direction with the workpiece clamped. The end effector of claim 8 .

11. In an end effector attached to a robot, a first finger portion and a second finger portion, at least one of which is supported so as to be movable toward and away from each other in a first direction and capable of clamping a workpiece; The first finger portion has a first surface capable of contacting a workpiece in the first direction, a second surface protruding in the first direction beyond the first surface and contacting the workpiece, and a third surface disposed opposite the second surface in a second direction that intersects with the first direction, The second finger portion has a fourth surface that is disposed opposite to the first surface and is capable of contacting a workpiece in the first direction, and a fifth surface that contacts the third surface in the second direction while clamping the workpiece. An end effector characterized by:

12. The body portion includes: a slide portion that supports the first finger portion and the second finger portion so as to be slidable; a first driving unit that drives the first finger unit to slide on the sliding unit; A second driving unit that can be driven independently of the first finger unit and drives the second finger unit to slide on the sliding unit. The end effector of claim 1 .

13. The slide portion includes a guide member, a first finger support member that is guided in a straight line by the guide member and supports the first finger portion, and a second finger support member that is guided in a straight line by the guide member and supports the second finger portion. The end effector of claim 12 .

14. The slide portion has a first parallel link mechanism that translates a first finger support member that supports the first finger portion, and a second parallel link mechanism that translates a second finger support member that supports the second finger portion. The end effector of claim 12 .

15. An end effector according to any one of claims 1 to 14; a robot to which the end effector is attached and capable of changing the position and orientation of the end effector; A control unit that controls the robot and the end effector. A robot system comprising:

16. A method for controlling an end effector attached to a robot of a robot system having a controller, the method comprising: first and second fingers, at least one of which is supported movably so as to move toward and away from each other in a first direction and capable of gripping a workpiece; the first finger portion has a first abutment portion capable of abutting against a workpiece in the first direction, a butting portion against which the workpiece is butted in a second direction that intersects with the first direction, and a first transmission portion that transmits a force received from the workpiece in the second direction at the butting portion; the second finger portion has a second abutting portion capable of abutting against a workpiece in the first direction, and a first pressure receiving portion that receives a force from the workpiece in the second direction at the abutting portion in a state in which the workpiece is clamped, in the second direction via the first transmission portion; a gripping step in which the control unit grips a workpiece with the first finger portion and the second finger portion; The control unit includes a pressing process of pressing the workpiece gripped by the first finger portion and the second finger portion in the second direction via the abutment portion. A method for controlling an end effector comprising the steps of:

17. an end effector including a first finger portion and a second finger portion, at least one of which is supported so as to be movable toward and away from each other in a first direction and capable of gripping a workpiece; a robot to which the end effector is attached and capable of changing the position and orientation of the end effector; a control unit that controls the robot and the end effector, the first finger portion has a first abutment portion capable of abutting against a workpiece in the first direction, a butting portion against which the workpiece is butted in a second direction that intersects with the first direction, and a first transmission portion that transmits a force received from the workpiece in the second direction at the butting portion; the second finger portion has a second abutment portion capable of abutting against a workpiece in the first direction, and a first pressure receiving portion that receives a force from the workpiece in the second direction at the abutting portion in a state in which the workpiece is clamped, in the second direction via the transmission portion; a gripping step in which the control unit grips a workpiece with the first finger portion and the second finger portion; The control unit includes a pressing process of pressing the workpiece gripped by the first finger portion and the second finger portion in the second direction via the abutment portion. A method for controlling a robot system comprising:

18. A method for manufacturing an article, comprising the steps of: manufacturing an article by using the robot system according to claim 15;

19. A program for causing a computer to execute the control method for a robot system according to claim 17.

20. A computer-readable recording medium storing the program according to claim 19.

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