Robot system and control method of robot system

Abstract

To provide a robot system that can perform at least either of fastening and removing a fastening member, even when the fastening member is arranged at a narrow position.SOLUTION: A robot system 100 comprises an engaging member 22 that engages with a fastening member, a robot arm part 10 on which the engaging member 22 is mounted to rotate the engaging member 22, and a control part, The control part performs rotating operation of making the robot arm part 10 rotate the engaging member 22 in a predetermined rotating direction, with the engaging member 22 engaging with the fastening member, and idling operation of rotating the robot arm part 10 in the opposite direction of the predetermined rotating direction with respect to the engaging member 22, while idling the engaging member 22 relatively.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a robot system and a control method for a robot system. [Background technology]

[0002] Conventionally, a robot system has been disclosed that fastens a fastening member by rotating the fastening member. Patent Document 1 discloses a robot system including a robot arm and a nut runner attached to the tip of the robot arm. The nut runner is a device that screws in a bolt by rotating the bolt. The nut runner includes a bit portion that engages with the head of the bolt and a motor that rotates the bit portion. The bit portion has a rod shape. The motor is disposed above the bit portion, and the rotation axis of the motor coincides with the axis of the rod-shaped bit portion. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2017-104027 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the robot system disclosed in Patent Document 1, the bolt is tightened by a nut runner. In this case, in order to obtain sufficient rotational torque for tightening or removing the bolt, the motor of the nut runner becomes large. Therefore, when the bolt is placed in a narrow position, the nut runner cannot be placed in the narrow position, which causes a problem that the bolt cannot be tightened or removed.

[0005] This disclosure has been made to solve the problems described above, and one object of this disclosure is to provide a robot system and a control method for a robot system that are capable of at least one of fastening and removing a fastening member even when the fastening member is placed in a narrow position. [Means for solving the problem]

[0006] A robot system according to a first aspect of this disclosure includes an engagement member that engages with a fastening member, a robot arm section to which the engagement member is attached and that rotates the engagement member, and a control section that performs a rotational action to rotate the engagement member in a predetermined rotational direction by the robot arm section while the engagement member is engaged with the fastening member, and an idling action to rotate the robot arm section in a direction opposite to the predetermined rotational direction relative to the engagement member while rotating the engagement member relatively idly.

[0007] The robot system according to the first aspect of the disclosure includes a control unit that performs a rotation operation in which the robot arm unit rotates the engaging member in a predetermined rotation direction while the engaging member is engaged with the fastening member, and an idling operation in which the robot arm unit rotates the engaging member in a direction opposite to the predetermined rotation direction relative to the engaging member while idling the engaging member relatively. As a result, the fastening member can be rotated by the rotation operation and idling operation of the robot arm unit, so that the configuration for rotating the fastening member can be prevented from becoming large compared to a case in which the fastening member is rotated by a motor with a rotation torque equivalent to that of the robot arm unit. As a result, even if the fastening member is disposed in a narrow position, at least one of fastening and removal of the fastening member can be performed. In addition, since the fastening member can be rotated by the rotation operation and idling operation of the robot arm unit, at least one of fastening and removal of the fastening member can be easily performed using the robot arm unit.

[0008] A control method for a robot system according to a second aspect of this disclosure includes performing a rotational operation in which the engaging member is attached with a robot arm section that rotates the engaging member while the engaging member is engaged with a fastening member, and performing an idling operation in which the robot arm section rotates the engaging member in a direction opposite to the predetermined rotational direction relative to the engaging member while rotating the engaging member relatively idling.

[0009] The control method of the robot system according to the second aspect of the disclosure includes, as described above, performing a rotation operation to rotate the engagement member in a predetermined rotation direction by a robot arm unit to which the engagement member is attached and which rotates the engagement member in a state in which the engagement member is engaged with the fastening member, and performing an idling operation to rotate the robot arm unit in a direction opposite to the predetermined rotation direction relative to the engagement member while rotating the engagement member relatively idling. As a result, since the fastening member can be rotated by the rotation operation and idling operation by the robot arm unit, it is possible to suppress an increase in size of the configuration for rotating the fastening member compared to a case in which the fastening member is rotated by a motor with a rotation torque equivalent to that of the robot arm unit. As a result, it is possible to provide a control method of the robot system that can perform at least one of fastening and removal of the fastening member even when the fastening member is arranged in a narrow position. In addition, since the fastening member can be rotated by the rotation operation and idling operation by the robot arm unit, it is possible to provide a control method of the robot system that can easily perform at least one of fastening and removal of the fastening member using the robot arm unit. Effect of the Invention

[0010] The robot system and the control method for the robot system according to the present disclosure can at least one of fastening and removing a fastening member even when the fastening member is placed in a narrow position. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 illustrates a robotic system according to one embodiment. [Diagram 2]FIG. 13 is a diagram illustrating a screw member rotating mechanism of the robot system according to one embodiment. [Diagram 3] 3A and 3B are views showing an engagement member, a screw member, and a fastened member of a screw member rotation mechanism according to one embodiment. [Figure 4] FIG. 1 is a block diagram of a robotic system according to one embodiment. [Diagram 5] FIG. 11 is a flow diagram illustrating an operation of the robot system according to one embodiment when tightening a screw member. [Figure 6] 11A and 11B are diagrams illustrating a pre-fastening operation of the robot system according to one embodiment. [Figure 7] FIG. 13 is a diagram illustrating a rotational motion in a final tightening operation of a robot system according to one embodiment. [Figure 8] FIG. 13 is a diagram illustrating an idling operation in a final tightening operation of a robot system according to an embodiment. [Figure 9] FIG. 11 is a flowchart illustrating an operation of the robot system according to one embodiment when loosening a screw member. [Figure 10] 13A to 13C are diagrams illustrating an operation of moving a screw member upward when loosening the screw member of the robot system according to one embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings.

[0013] (Robot Systems) The configuration of the robot system 100 will be described. As shown in FIG. 1, the robot system 100 performs an operation of tightening and loosening a screw member 1 on a fastened member 2. The robot system 100 provisionally tightens the screw member 1 on the fastened member 2 and then performs final tightening. The robot system 100 also performs final loosening of the screw member 1 in a state where it is fastened to the fastened member 2 and then provisional loosening. Note that "full loosening" means loosening the screw member 1 in a fastened state, and "provisional loosening" means loosening the screw member 1 in a fully loosened state. The fastened member 2 includes, for example, a pair of flat plate-like members 2a and 2b, and the pair of flat plate-like members 2a and 2b are fastened together by the screw member 1. Note that the screw member 1 is an example of a fastening member.

[0014] The robot system 100 includes a robot arm unit 10, a screw member rotating mechanism 20, a force sensor 30, and a control unit 40. The screw member rotating mechanism 20 is an example of a fastening member rotating mechanism. The force sensor 30 is an example of a torque sensor.

[0015] The configuration of the robot arm unit 10 will be described. The robot arm unit 10 is a vertical multi-joint type robot arm unit 10. The robot arm unit 10 includes a plurality of joints JT. For example, the robot arm unit 10 includes six joints JT1, JT2, JT3, JT4, JT5, and JT6. That is, the robot arm unit 10 is a robot arm unit 10 having six axes. In addition, a drive unit 11 shown in FIG. 4 is disposed in each of the joints JT1 to JT6.

[0016] The configuration of the screw member rotating mechanism 20 will be described. As shown in Fig. 2, the screw member rotating mechanism 20 is a mechanism for rotating the screw member 1. The screw member rotating mechanism 20 includes an attachment member 21, an engagement member 22, a drive unit 23, a gear unit 24, a support member 25, and a movement mechanism 26. The screw member rotating mechanism 20 is attached to the robot arm unit 10.

[0017] In this embodiment, the mounting member 21 is an elongated member whose base end is attached to the robot arm unit 10. The mounting member 21 has a plate shape. The mounting member 21 includes a rectangular first portion 21a and a second portion 21b protruding from the tip of the first portion 21a. The base end of the first portion 21a is attached to the tip of the robot arm unit 10. Specifically, the base end of the first portion 21a is attached to the tip of the robot arm unit 10 via the force sensor 30. The first portion 21a rotates around the rotation axis of the joint JT6.

[0018] In this embodiment, the engaging member 22 is disposed at the tip of the mounting member 21, and the driving unit 23 is disposed at the center of the mounting member 21. Specifically, the engaging member 22 is attached to the underside of the tip of the mounting member 21 via the engaging unit gear 24b. The engaging member 22 has a columnar shape. As shown in FIG. 3, the tip of the engaging member 22 is inserted into the hole 1b of the screw head 1a of the screw member 1. The tip of the engaging member 22 and the hole 1b of the screw head 1a have, for example, a hexagonal shape. The screw member 1 has a threaded portion 1c that is inserted into a screw hole 2c of the fastened member 2.

[0019] 2, the driving unit 23 is disposed on the upper surface of the central portion of the mounting member 21. The driving unit 23 includes a servo motor, an encoder, and a reducer. The driving shaft of the driving unit 23 passes through the mounting member 21, and a driving unit gear 24a is attached to the tip of the driving shaft of the driving unit 23.

[0020] In this embodiment, the gear portion 24 is disposed on the mounting member 21 and transmits the rotational force of the drive portion 23 to the engagement member 22. Specifically, the gear portion 24 includes a drive portion gear 24a, an engagement portion gear 24b, and an intermediate gear 24c. The drive portion gear 24a, the engagement portion gear 24b, and the intermediate gear 24c are, for example, spur gears. The engagement portion gear 24b and the intermediate gear 24c are attached to the mounting member 21. The drive portion gear 24a rotates around the A1 axis, which is the rotation axis of the drive portion 23. The engagement portion gear 24b rotates around the A2 axis, which is the rotation axis of the engagement member 22. The intermediate gear 24c is disposed between the drive portion gear 24a and the engagement portion gear 24b, and transmits the rotation of the drive portion gear 24a to the engagement portion gear 24b. In addition, two intermediate gears 24c are disposed. The two intermediate gears 24c are referred to as intermediate gears 24c1 and 24c2. The drive gear 24a and the intermediate gear 24c1 mesh with each other, the intermediate gear 24c1 and the intermediate gear 24c2 mesh with each other, and the intermediate gear 24c2 and the engagement gear 24b mesh with each other. The intermediate gears 24c1 and 24c2 rotate around the A3 axis and the A4 axis, respectively. The intermediate gears 24c1 and 24c2 are idle gears.

[0021] In this embodiment, the diameter r1 of the drive gear 24a is equal to the diameter r2 of the engagement gear 24b. The number of teeth of the drive gear 24a is equal to the number of teeth of the engagement gear 24b. That is, the rotation of the drive unit 23 is not accelerated or decelerated between the drive gear 24a and the engagement gear 24b.

[0022] In this embodiment, the diameter r1 of the drive gear 24a is smaller than the diameter r3 of the intermediate gear 24c. The diameter r2 of the engagement gear 24b is smaller than the diameter r3 of the intermediate gear 24c. The diameter r3 of the intermediate gear 24c1 is equal to the diameter r3 of the intermediate gear 24c2.

[0023] In this embodiment, the support member 25 supports the screw head 1a of the screw member 1 from below. Specifically, the support member 25 has a flat plate shape. The tip of the support member 25 has a U-shape. The threaded portion 1c of the screw member 1 is inserted into the U-shaped tip of the support member 25. As a result, the screw head 1a of the screw member 1 is supported by the U-shaped tip of the support member 25. The support member 25 is attached to a moving mechanism 26.

[0024] In this embodiment, the moving mechanism 26 moves the support member 25 in a direction toward or away from the screw member 1. The moving mechanism 26 is attached to the lower surface of the mounting member 21. The moving mechanism 26 includes an L-shaped fixed part 26a connected to the mounting member 21 and a moving part 26b that moves relative to the fixed part 26a. The support member 25 is attached to the moving part 26b and moves together with the moving part 26b. The moving mechanism 26 is, for example, an air cylinder. A tube connected to an air source is connected to the moving mechanism 26, and the control unit 40 controls the supply of air from the air source to move the moving part 26b.

[0025] The force sensor 30 will now be described. In this embodiment, the force sensor 30 detects the torque applied to the engaging member 22. Specifically, the force sensor 30 is disposed between the tip of the robot arm unit 10 and the mounting member 21 of the screw member rotation mechanism 20. The force sensor 30 detects the torque generated when the robot arm unit 10 moves to rotate the engaging member 22. The torque detected by the force sensor 30 is transmitted to the control unit 40.

[0026] The configuration of the control unit 40 will be described. As shown in FIG. 4, the control unit 40 is a robot controller. The control unit 40 includes a main control unit 41, a servo control unit 42, and a drive circuit unit 43. The main control unit 41 and the servo control unit 42 include, for example, a CPU (Central Processing Unit). The main control unit 41 controls the drive unit 11 of the robot arm unit 10 and the drive unit 23 of the screw member rotating mechanism 20. The servo control unit 42 controls the power supplied to the drive unit 11 of the robot arm unit 10 based on a command from the main control unit 41. The drive circuit unit 43 supplies drive power to the drive unit 11 of the robot arm unit 10 and the drive unit 23 of the screw member rotating mechanism 20. The drive circuit unit 43 is disposed for each of the drive units 11 of the robot arm unit 10. Each of the drive units 11 includes a servo motor, an encoder, and a reducer.

[0027] In this embodiment, the control unit 40 coordinates the drive unit 23 of the screw member rotating mechanism 20 with the joint axes of the robot arm unit 10 as an external axis. The control unit 40 is configured to be capable of controlling seven or more axes. The control unit 40 controls the drive of a total of seven axes, including six axes of joints JT1 to JT6 of the robot arm unit 10 and one axis of the drive unit 23 of the screw member rotating mechanism 20.

[0028] (Method of controlling a robot system) Next, a control method for the robot system 100 when fastening the screw member 1 into the workpiece 2 will be described with reference to FIG.

[0029] In step S1, the control unit 40 moves the robot arm unit 10 to move the engagement member 22 of the screw member rotating mechanism 20 above the screw member 1, and engages the engagement member 22 with the screw member 1. Specifically, the tip of the engagement member 22 is inserted into the hole 1b of the screw head 1a. Note that the position of the screw member 1 may be taught to the control unit 40 in advance, and the robot arm unit 10 may be moved based on the taught position, or the robot arm unit 10 may be moved based on an image of the screw member 1 captured by the imaging unit. In addition, the screw member 1 is placed in advance in the screw hole 2c of the fastened member 2. By engaging the engagement member 22 with the screw member 1, the central axis of rotation of the screw member 1 coincides with the A2 axis, which is the rotation axis of the engagement member 22.

[0030] In step S2, as shown in FIG. 6, the control unit 40 executes a process of provisionally tightening the screw member 1 by rotating the engagement member 22 by the drive unit 23 around the central axis of the screw member 1 in a state in which the engagement member 22 is engaged with the screw member 1. The control unit 40 rotates the engagement member 22 by the drive unit 23 so that the rotation speed of the screw member 1 during provisional tightening is greater than the rotation speed of the screw member 1 during final tightening. The rotation speed during provisional tightening and final tightening means the average rotation speed of the screw member 1 during provisional tightening and final tightening. In addition, the gear unit 24 rotates together with the rotation of the drive unit 23 during provisional tightening. That is, the rotation of the drive unit 23 rotates the drive unit gear 24a, the intermediate gear 24c1, the intermediate gear 24c2, and the engagement unit gear 24b, thereby rotating the engagement member 22. In addition, the engagement member 22 rotates, for example, to the A21 side.

[0031] The control unit 40 performs a process of provisionally fastening the screw member 1 within a range in which the torque applied to the screw member 1 does not exceed a predetermined first torque threshold. Specifically, the control unit 40 performs a process of provisionally fastening the screw member 1 within a range in which the current value of the current flowing through the drive unit 23 does not exceed a predetermined current threshold. In more detail, the control unit 40 monitors the current value of the current flowing from the drive circuit unit 43 to the drive unit 23, and performs a process of provisionally fastening the screw member 1 within a range in which the monitored current value does not exceed the predetermined current threshold. In addition, the predetermined current threshold is set in advance so that the screw member 1 does not overtighten the fastened member 2.

[0032] In step S3, the control unit 40 performs a process of final tightening the screw member 1 by rotating the engaging member 22 with the robot arm unit 10. In this embodiment, in the final tightening operation, the control unit 40 performs a rotation operation in which, with the engaging member 22 engaged with the screw member 1, the robot arm unit 10 to which the engaging member 22 is attached rotates the engaging member 22 in a predetermined rotation direction, and an idling operation in which the robot arm unit 10 rotates the engaging member 22 in a direction opposite to the predetermined rotation direction relative to the engaging member 22 while rotating the engaging member 22 idly relative to the engaging member 22.

[0033] As shown in FIG. 7, in the rotation operation of the final fastening process, the control unit 40 moves the robot arm unit 10 so that the engagement member 22 rotates around the A2 axis. In the rotation operation, the control unit 40 rotates the engagement member 22, for example, to the A21 side as a predetermined rotation direction. The gear unit 24 is locked during the rotation operation. When performing the rotation operation, the control unit 40 generates a torque in the drive unit 23 so that the drive unit gear 24a, the intermediate gear 24c1, the intermediate gear 24c2, and the engagement unit gear 24b do not rotate. As a result, the robot arm unit 10 rotates, but the gear unit 24 does not rotate. In other words, the control unit 40 controls the drive unit 23 to hold the rotation position so that the gear unit 24 does not rotate. The control unit 40 controls the position and rotation angle of the joint JT6 of the robot arm unit 10 to which the screw member rotating mechanism 20 is attached so that the entire screw member rotating mechanism 20 rotates around the central axis of the screw member 1 toward the A21 side with the rotation of the gear unit 24 locked. As a result, the screw member 1 rotates around the central axis toward the A21 side with the rotation of the robot arm unit 10. In the rotation operation, for example, the robot arm unit 10 rotates the engagement member 22 60 degrees toward the A21 side around the central axis of the screw member 1 by the control unit 40. Note that the rotation speed of the screw member 1 when performing the final tightening described above refers to the rotation speed of the screw member 1 during the rotation operation.

[0034] 8, in the idling operation of the final fastening process, with the engaging member 22 engaged with the screw member 1, the control unit 40 rotates the entire screw member rotating mechanism 20 toward the A22 side, which is the direction opposite to the predetermined rotation direction, by the robot arm unit 10, while causing the drive unit 23 to relatively rotate the engaging member 22 toward the A21 side, which is the predetermined rotation direction, at a rotational speed equivalent to the rotation by the robot arm unit 10. Note that the rotational speed referred to here means the average rotational speed of the robot arm unit 10 and the engaging member 22 during the idling operation.

[0035] In the idling operation, the control unit 40 controls the position and rotation angle of the joint JT6 of the robot arm unit 10 so that the entire screw member rotating mechanism 20 rotates to the A22 side around the central axis of the screw member 1 by operating the robot arm unit 10. Unlike the rotation operation, the gear unit 24 rotates together with the rotation of the drive unit 23 during the idling operation. That is, the drive unit gear 24a, the intermediate gear 24c1, the intermediate gear 24c2, and the engagement unit gear 24b rotate due to the rotation of the drive unit 23. In the idling operation, the control unit 40 controls the rotation of the drive unit 23 to relatively rotate the engagement member 22 to the A21 side around the A2 axis in the opposite direction to the rotation of the robot arm unit 10. That is, in the idling operation, the control unit 40 controls the operation of the robot arm unit 10 and the drive unit 23 so that the screw member 1 does not rotate.

[0036] In the idling operation, for example, the robot arm unit 10 rotates the entire screw member rotating mechanism 20 60 degrees toward the A22 side around the central axis of the screw member 1. In the idling operation, the drive unit 23 rotates the engagement member 22 60 degrees toward the A21 side relative to the robot arm unit 10 around the central axis of the screw member 1 by the control unit 40. The control unit 40 aligns the timing at which the operation of the robot arm unit 10 in the idling operation starts with the timing at which the operation of the drive unit 23 starts, and also aligns the timing at which the operation of the robot arm unit 10 in the idling operation ends with the timing at which the operation of the drive unit 23 ends, thereby rotating the engagement member 22 at a rotation speed equivalent to the rotation by the robot arm unit 10. In other words, the control unit 40 controls the operation of the drive unit 23 so that the engagement member 22 rotates toward the A21 side when the screw member rotating mechanism 20 rotated by the robot arm unit 10 is used as a reference. On the other hand, when the screw member 1 is used as a reference, the engagement member 22 is in a stopped state with its rotational position not changing during the idling operation.

[0037] The control unit 40 performs final tightening of the screw member 1 by performing a rotation operation and an idling operation. During final tightening, the control unit 40 performs a process of final tightening the screw member 1 until the torque detected by the force sensor 30 reaches a predetermined second torque threshold. In this embodiment, the control unit 40 alternately performs a rotation operation and an idling operation while the engagement member 22 is engaged with the screw member 1. The control unit 40 performs a rotation operation until the torque detected by the force sensor 30 during the rotation operation reaches a predetermined second torque threshold. The predetermined second torque threshold is set in advance so that the torque during final tightening is greater than the torque during temporary tightening. For example, the predetermined second torque threshold is greater than the above-mentioned predetermined first torque threshold. The control unit 40 rotates the robot arm unit 10 by equal angles in the rotation operation and the idling operation. After the completion of final tightening, the robot arm unit 10 detaches the engagement member 22 from the screw head 1a. The second torque threshold is an example of a predetermined torque threshold.

[0038] When a plurality of screw members 1 are arranged, the operations from step S1 to step S3 are repeated.

[0039] Next, a method of controlling the robot system 100 when loosening the screw member 1 will be described with reference to FIG.

[0040] In step S11, as shown in FIG. 6, the control unit 40 moves the robot arm unit 10 to move the engagement member 22 of the screw member rotating mechanism 20 above the screw member 1, and engages the engagement member 22 with the screw member 1.

[0041] In step S12, the control unit 40 performs a process of final loosening the screw member 1 by rotating the engaging member 22 with the robot arm unit 10 while the engaging member 22 is engaged with the screw member 1. In this embodiment, when performing the final loosening, the control unit 40 performs a process of loosening the screw member 1 by rotating and spinning in a state where the engaging member 22 is engaged with the screw member 1, similar to when performing the final tightening. Specifically, even when performing the final loosening, the gear unit 24 is locked during the rotating operation, and rotates together with the rotation of the drive unit 23 during the spinning operation. Note that in the final loosening operation, the screw member 1 is rotated in the opposite direction to that in the final tightening.

[0042] In detail, when performing the final loosening, the control unit 40 generates a torque in the drive unit 23 so that the gear unit 24 does not rotate in the rotation operation, similar to when performing the final tightening. As a result, in the rotation operation for the final loosening, the robot arm unit 10 rotates toward the A22 side, while the gear unit 24 does not rotate. As a result, the screw member 1 rotates toward the A22 side with the rotation of the robot arm unit 10. In the rotation operation for the final loosening, the control unit 40 moves the robot arm unit 10 so that the engaging member 22 rotates toward the A22 side around the A2 axis. Then, in the idling operation for the final loosening, similar to when performing the final tightening, the control unit 40 controls the operation of the drive unit 23 so that the engaging member 22 rotates relatively in the A22 direction while rotating the robot arm unit 10 in the A21 direction around the A2 axis.

[0043] In step S13, in the present embodiment, the control unit 40 performs a process of temporarily loosening the screw member 1 by rotating the engaging member 22 by the driving unit 23. The control unit 40 rotates the engaging member 22 by the driving unit 23 so that the rotation speed of the screw member 1 during the temporary loosening is greater than the rotation speed of the screw member 1 during the main loosening. Note that the rotation speeds during the temporary loosening and the main loosening mean the average rotation speeds of the screw member 1 during the temporary loosening and the main loosening. Also, the gear unit 24 rotates together with the rotation of the driving unit 23 during the temporary loosening. That is, due to the rotation of the driving unit 23, the driving unit gear 24a, the intermediate gear 24c1, the intermediate gear 24c2, and the engaging portion gear 24b rotate, causing the engaging member 22 to rotate. Also, the engaging member 22 rotates, for example, toward the A22 side.

[0044] In step S14, as shown in FIG. 10, in the present embodiment, the control unit 40 performs a process of moving the support member 25 downward by the moving mechanism 26 to a position below the screw head 1a, which is the position where the screw head 1a is supported, in a state where the screw member 1 is loosened by being temporarily loosened. Thereby, the screw head 1a of the screw member 1 is supported by the U-shaped tip of the support member 25. Then, the control unit 40 performs a process of moving the screw member 1 upward by the robot arm unit 10 in a state where the screw head 1a is supported by the support member 25. Here, when the screw member 1 is caught in the screw hole 2c, the screw member 1 does not move upward. When the screw member 1 is not caught in the screw hole 2c, the screw member 1 moves upward. The control unit 40 determines whether or not the screw member 1 is caught in the screw hole 2c based on the height of the robot arm unit 10 after performing the process of moving the screw member 1 upward by the robot arm unit 10. If the screw member 1 was caught in the screw hole 2c, the temporary loosening operation is repeated. After the completion of the temporary loosening, the robot arm unit 10 disengages the engaging member 22 from the screw head 1a. Also, when a plurality of screw members 1 are arranged, the operations from step S11 to step S14 are repeated.

[0045] [Effects of the Present Embodiment] In the robot system 100, in a state where the engaging member 22 is engaged with the screw member 1 as a fastening member, the control unit 40 performs a rotation operation of rotating the engaging member 22 in a predetermined rotation direction by the robot arm unit 10, and an idle rotation operation of rotating the robot arm unit 10 in a direction opposite to the predetermined rotation direction with respect to the engaging member 22 while relatively idling the engaging member 22. Thereby, since the screw member 1 can be rotated by the rotation operation and the idle rotation operation of the robot arm unit 10, compared with the case where the screw member 1 is rotated by a rotation torque equivalent to that of the robot arm unit 10 by a motor, it is possible to suppress an increase in the size of the configuration for rotating the screw member 1. As a result, even when the screw member 1 is arranged in a narrow position, at least one of fastening and removing the screw member 1 can be performed. Further, since the screw member 1 can be rotated by the rotation operation and the idle rotation operation of the robot arm unit 10, at least one of fastening and removing the screw member 1 can be easily performed using the robot arm unit 10. Further, when the screw member 1 cannot be sufficiently rotated by one rotation operation, the position of the robot arm unit 10 can be returned without rotating the screw member 1 by performing an idle rotation operation. Therefore, since the screw member 1 can be sufficiently rotated while making the operation range of the robot arm unit 10 compact, at least one of fastening and removing the screw member 1 can be performed even when the screw member 1 is arranged in a narrower position.

[0046] The robot system 100 is attached to the robot arm section 10 and includes a screw member rotating mechanism 20 as a fastening member rotating mechanism including an engaging member 22. The robot system 100 includes a drive section 23 that rotates the engaging member 22 around the central axis of a screw member 1 as a fastening member. In an idling operation, the control section 40 rotates the engaging member 22 relatively in a predetermined rotation direction by the drive section 23 at a rotation speed corresponding to the rotation by the robot arm section 10 while rotating the entire screw member rotating mechanism 20 in a direction opposite to a predetermined rotation direction by the robot arm section 10 with the engaging member 22 engaged with the screw member 1. This allows the engaging member 22 to be rotated relatively to the robot arm section 10 by the operation of the drive section 23. Therefore, the rotation operation and the idling operation can be appropriately performed by the operation of the drive section 23 and the operation of the robot arm section 10, so that at least one of fastening and removal of the screw member 1 can be performed even when the screw member 1 is arranged in a narrow position. Furthermore, since the robot system 100 includes the drive unit 23 that rotates the engaging member 22 around the central axis of the screw member 1, it is possible to combine rotating the screw member 1 by the operation of the drive unit 23 for provisional tightening and loosening, and rotating the screw member 1 by the operation of the robot arm unit 10 for final tightening and loosening. Therefore, it is possible to shorten the time required for the tightening and loosening of the screw member 1 compared to when all rotations of the screw member 1 are performed by the robot arm unit 10. Furthermore, since final tightening and final loosening, which require a relatively large torque, are performed by the robot arm unit 10, it is possible to effectively prevent the drive unit 23 from becoming large.

[0047] The control unit 40 alternately executes a rotation operation and an idling operation in a state in which the engaging member 22 is engaged with the screw member 1 as a fastening member. As a result, even if the operation of tightening or loosening the screw member 1 is not completed in one rotation operation, by alternately executing a rotation operation and an idling operation, the rotation operation can be continued multiple times while the screw member 1 and the engaging member 22 are in a mutually engaged state. Therefore, an increase in the work time required for the operation of tightening or loosening the screw member 1 can be suppressed.

[0048] The robot system 100 includes a force sensor 30 as a torque sensor that detects the torque applied to the engaging member 22. The control unit 40 performs a rotation operation until the torque detected by the force sensor 30 reaches a second torque threshold value as a predetermined torque threshold value. As a result, by performing a rotation operation based on the torque detected by the force sensor 30, it is possible to appropriately perform an operation of tightening or loosening the screw member 1 as a fastening member. Furthermore, when the force sensor 30 is provided as a torque sensor, the torque acquired from the force sensor 30 is more accurate than when the torque is acquired from the current value of the current flowing through the drive unit 23, so that the screw member 1 can be fastened with an appropriate fastening force based on the detected torque.

[0049] The screw member rotating mechanism 20 as a fastening member rotating mechanism includes a gear unit 24 that transmits the rotational force of the drive unit 23 to the engaging member 22. The gear unit 24 is locked during a rotating operation. Also, the gear unit 24 rotates together with the rotation of the drive unit 23 during an idling operation. As a result, by locking the gear unit 24 during a rotating operation, the rotational force of the robot arm unit 10 is transmitted to the engaging member 22, so that the engaging member 22 can be rotated by the robot arm unit 10. Also, since the gear unit 24 rotates together with the rotation of the drive unit 23 during an idling operation, the engaging member 22 can be idling relative to the robot arm unit 10 by the operation of the drive unit 23. Therefore, by locking the gear unit 24 during a rotating operation and rotating it together with the drive unit 23 during an idling operation, the screw member 1 can be appropriately rotated by the robot arm unit 10. Also, in general, a servo motor can output a larger torque when it is held in a stopped state than when it is rotating. Therefore, when the drive unit 23 includes a servo motor, the drive unit 23 can be prevented from becoming large by rotating the screw member 1 with the robot arm unit 10 in a state in which the gear unit 24 is locked by the drive unit 23 holding the rotation stopped, compared to when the screw member 1 is rotated only by the rotation force of the drive unit 23. Therefore, even when the drive unit 23 locks the gear unit 24 to transmit the rotation force of the robot arm unit 10 to the engagement member 22, the device configuration can be prevented from becoming large, so that at least one of fastening and removal of the screw member 1 can be performed even when the screw member 1 is arranged in a narrow position.

[0050] The screw member rotating mechanism 20 as the fastening member rotating mechanism includes an elongated mounting member 21 whose base end is attached to the robot arm unit 10. The driving unit 23 is disposed in the center of the mounting member 21. The engaging member 22 is disposed at the tip of the mounting member 21. As a result, even if the screw member 1 is disposed in a narrow space, the elongated mounting member 21 can be inserted into the narrow space to fasten the screw member 1. In addition, since the engaging member 22 is disposed at the tip of the mounting member 21, the screw member 1 can be fastened at a position farther away from the robot arm unit 10. In addition, since the driving unit 23 is disposed at the center of the mounting member 21, the driving unit 23 can be prevented from coming into contact with the fastened member 2, unlike when the driving unit 23 is disposed at the tip of the mounting member 21.

[0051] The screw member rotation mechanism 20 as a fastening member rotation mechanism includes a gear unit 24 that is disposed on the mounting member 21 and transmits the rotational force of the drive unit 23 to the engagement member 22. The gear unit 24 includes a drive unit gear 24a that rotates about the rotation axis of the drive unit 23, an engagement unit gear 24b that rotates about the rotation axis of the engagement member 22, and an intermediate gear 24c that is disposed between the drive unit gear 24a and the engagement unit gear 24b and transmits the rotation of the drive unit gear 24a to the engagement unit gear 24b. As a result, even if the mounting member 21 is relatively long and the interval between the drive unit gear 24a and the engagement unit gear 24b is relatively large, the rotation of the drive unit gear 24a can be transmitted to the engagement unit gear 24b via the intermediate gear 24c.

[0052] The diameter r1 of the drive gear 24a and the diameter r2 of the engagement gear 24b are equal. This eliminates the need to consider the speed increase ratio and speed reduction ratio between the drive gear 24a and the engagement gear 24b, unlike when the diameter r1 of the drive gear 24a and the diameter r2 of the engagement gear 24b are different. This makes it possible to prevent the control of the rotation of the drive unit 23 by the control unit 40 from becoming complicated when the engagement member 22 is rotated idly relative to the operation of the robot arm unit 10 in the idling operation.

[0053] The diameter r2 of the engagement gear 24b is smaller than the diameter r3 of the intermediate gear 24c. This makes the engagement gear 24b smaller, so that the engagement gear 24b and the engagement member 22 connected to the engagement gear 24b can easily enter a narrow space.

[0054] The robot system 100 includes a support member 25 that supports a screw head 1a of a screw member 1 as a fastening member. The robot system 100 includes a movement mechanism 26 that moves the support member 25 in a direction toward or away from the screw member 1. The control unit 40 performs a process of loosening the screw member 1 by rotating and rotating freely while the engagement member 22 is engaged with the screw member 1. With the screw member 1 loosened, the control unit 40 performs a process of moving the support member 25 by the movement mechanism 26 to a position that supports the screw head 1a. Then, with the screw head 1a supported by the support member 25, the control unit 40 performs a process of moving the screw member 1 by the robot arm unit 10. With the screw head 1a supported by the support member 25, the control unit 40 can thus detect whether the screw member 1 is caught in the screw hole 2c by moving the screw member 1 by the robot arm unit 10.

[0055] The robot arm unit 10 includes a vertically articulated robot arm unit 10 having a plurality of joint axes. This allows the engaging member 22 to easily engage with the screw member 1 as a fastening member even when the screw member 1 is inclined with respect to the horizontal plane.

[0056] The control unit 40 controls the drive unit 23 as an external axis in cooperation with the joint axis of the robot arm unit 10. This makes it possible to easily cause the drive unit 23 and the robot arm unit 10 to operate in cooperation with each other.

[0057] [Variations] It should be noted that the embodiments disclosed herein are illustrative and not restrictive in all respects. The scope of the present disclosure is indicated by the claims, not by the description of the embodiments above, and further includes all modifications (variations) within the meaning and scope equivalent to the claims.

[0058] In the above embodiment, the provisional tightening and provisional loosening are performed by the operation of the drive unit 23 disposed in the screw member rotating mechanism 20 as the fastening member rotating mechanism, and the provisional loosening and final loosening are performed by the rotational operation and the idling operation that combines the operation of the robot arm unit 10 and the operation of the drive unit 23, but the present disclosure is not limited to this. In the present disclosure, the rotation of the fastening member, including provisional tightening and provisional loosening, may be performed only by the rotational operation and the idling operation of the robot arm unit. That is, only final tightening may be performed without provisional tightening, or only final loosening may be performed without provisional loosening. In addition, a drive unit that rotates the engaging member may not be provided. For example, a power transmission mechanism that switches between a state in which the operation of the robot arm unit is transmitted to the engaging member and a state in which it is not transmitted may be provided. As the power transmission mechanism, a one-way clutch, a ratchet mechanism, or an actuator that switches the state in which power is transmitted may be provided. In addition, the robot system may perform only one of the operations of tightening and loosening the fastening member. In addition, the drive unit may not be included in the fastening member rotating mechanism. For example, the drive unit may be disposed in the robot arm unit instead of in the fastening member rotation mechanism.

[0059] In the above embodiment, an example has been shown in which the engagement member 22 is rotated by 60 degrees relative to the robot arm unit 10 at a rotation speed corresponding to 60 degrees of rotation by the robot arm unit 10 in the idling operation, but the present disclosure is not limited to this. In the present disclosure, the rotation speed by the robot arm unit in the idling operation and the rotation speed of the engagement member by the drive unit may be different from each other. Furthermore, the amount of rotation by the robot arm unit may be other than 60 degrees, and the amount of rotation of the engagement member by the drive unit may be other than 60 degrees. Furthermore, the amount of rotation by the robot arm unit and the amount of rotation of the engagement member by the drive unit may be different from each other.

[0060] In the above embodiment, an example has been shown in which the rotation operation and the idling operation are alternately and repeatedly performed in a state in which the engagement member 22 is engaged with the screw member 1 as a fastening member, but the present disclosure is not limited to this. In the present disclosure, the rotation operation and the idling operation may be performed once each. Also, the rotation operation and the idling operation may be alternately performed in the order of the rotation operation, the idling operation, and the rotation operation, with the idling operation being performed only once.

[0061] In the above embodiment, an example has been described in which the gear portion 24 is locked during the rotational operation and rotates together with the drive portion 23 during the idling operation, but the present disclosure is not limited to this. In the present disclosure, the gear portion may be rotated during the rotational operation. That is, the robot arm portion and the gear portion may be rotated in a common rotational direction to rotate the fastening member by a predetermined rotational torque. Also, in cases such as when the holding torque of the drive portion is small, the gear portion may be rotated in the opposite direction to the rotational operation of the robot arm portion during the rotational operation.

[0062] In the above embodiment, an example has been shown in which the screw member rotation mechanism 20 as the fastening member rotation mechanism includes an elongated mounting member 21, a drive unit 23 arranged in the center of the mounting member 21, and an engagement member 22 arranged at the tip of the mounting member 21, but the present disclosure is not limited to this. In the present disclosure, the mounting member does not have to be elongated. Also, the engagement member may be directly attached to the robot arm. Also, the drive unit may be arranged at the tip or base end of the mounting member.

[0063] In the above embodiment, an example has been shown in which the rotation speed of the screw member 1 as a fastening member when performing temporary tightening is greater than the rotation speed of the screw member 1 when performing final tightening, but the present disclosure is not limited to this. In the present disclosure, the rotation speed of the fastening member when performing temporary tightening may be equal to the rotation speed of the fastening member when performing final tightening. Similarly, the rotation speed of the fastening member when performing temporary loosening may be equal to the rotation speed of the fastening member when performing final loosening.

[0064] In the above embodiment, an example has been shown in which the control unit 40 monitors the current value of the current flowing from the drive circuit unit 43 to the drive unit 23, but the present disclosure is not limited to this. In the present disclosure, a current detection unit that detects the current value of the current flowing to the drive unit may be separately provided, and the control unit may obtain the current value from the current detection unit.

[0065] In the above embodiment, the control unit 40 performs a rotation operation based on the torque detected by the force sensor 30 as a torque sensor, but the present disclosure is not limited to this. In the present disclosure, the control unit may perform a rotation operation based on the current value of the current flowing in the drive unit of the joint of the robot arm unit when performing a rotation operation. That is, a current sensor that detects the current flowing in the drive unit of the joint of the robot arm unit may be arranged as a torque sensor. In addition, when the control unit as a robot controller monitors the current flowing in the drive unit of the joint of the robot arm unit, the control unit may be arranged as a current sensor, thereby making the control unit a torque sensor. In addition, a torque sensor may be arranged in the engagement member, not between the robot arm unit and the fastening member rotation mechanism. In addition, a torque sensor may be arranged in the drive unit to detect the torque applied to the engagement member. In these cases, the torque of the drive unit may be detected by a force sensor, or the current flowing in the drive unit may be detected. In addition, the torque applied to the fastening member may be detected by a torque sensor, and a process of provisional fastening may be performed within a range in which the torque does not exceed a predetermined first torque threshold value.

[0066] In the above embodiment, an example was shown in which the engaging member 22 is disposed at the tip of the mounting member 21 and the rotation axis of the engaging member 22 does not coincide with the rotation axis of the drive unit 23, but the present disclosure is not limited to this. In the present disclosure, the rotation axis of the engaging member may coincide with the rotation axis of the drive unit, as in a nut runner. Even in this case, the configuration for rotating the fastening member can be prevented from becoming large by performing the rotational movement and idling movement of the robot arm unit, compared to the case in which the fastening member is rotated only by the drive unit, so that at least one of fastening and removal of the fastening member can be performed even if the fastening member is disposed in a narrow position.

[0067] In the above embodiment, the gear section 24 includes two intermediate gears 24c that transmit power between the drive gear 24a and the engagement gear 24b, but the present disclosure is not limited to this. In the present disclosure, the number of intermediate gears may be other than two, and the gear section may not include an intermediate gear. In addition, the drive gear and the engagement gear may be directly engaged without disposing an intermediate gear. In addition, the power of the drive section may be transmitted to the engagement member by a power transmission mechanism other than gears, such as a timing belt or a rack and pinion.

[0068] In the above embodiment, the diameter r1 of the drive gear 24a and the diameter r2 of the engagement gear 24b are equal to each other, but the present disclosure is not limited to this. In the present disclosure, the diameter of the drive gear and the diameter of the engagement gear may be different.

[0069] In the above embodiment, the diameter r2 of the engagement gear 24b is smaller than the diameter r3 of the intermediate gear 24c, but the present disclosure is not limited to this. In the present disclosure, the diameter of the engagement gear and the diameter of the intermediate gear may be the same. Similarly, the diameter of the drive gear and the diameter of the intermediate gear may be the same.

[0070] In the above embodiment, an example was shown in which an operation to check whether the screw member 1 is caught in the screw hole 2c is performed when loosening the screw member 1, but the present disclosure is not limited to this. In the present disclosure, an operation to check whether the screw member is caught in the screw hole may not be performed. For example, the screw member may be removed from the screw hole only by the rotational operation and idling operation of the robot arm unit without disposing a support member. Also, when performing an operation to check whether the screw member is caught in the screw hole, the screw member may be lifted from above instead of supporting the screw head from below with the support member. In other words, the support member may support the fastening member from above or side other than below.

[0071] In the above embodiment, an example has been given in which the fastening member of the present disclosure is the screw member 1, but the present disclosure is not limited to this. In the present disclosure, the fastening member may be a fastening member other than the screw member 1. For example, the fastening member may be a male thread member such as a bolt, or a female thread member such as a nut.

[0072] In the above embodiment, an example has been described in which the moving mechanism 26 is disposed in the screw member rotating mechanism 20 as the fastening member rotating mechanism, but the present disclosure is not limited to this. In the present disclosure, the moving mechanism may be disposed in a robot arm portion or the like other than the fastening member rotating mechanism.

[0073] In the above embodiment, the control unit 40 is a robot controller, and the robot controller controls the joint shaft of the robot arm unit 10 and the fastening member rotation mechanism, which is the screw member rotation mechanism 20 as an external shaft, but the present disclosure is not limited to this. In the present disclosure, a control unit that controls the fastening member rotation mechanism as an external shaft may be arranged separately from the robot controller. Also, a control unit higher than the robot controller that controls the joint shaft of the robot arm unit and the fastening member rotation mechanism as an external shaft may be arranged.

[0074] In the above embodiment, an example has been shown in which the robot arm unit 10 is a vertical multi-joint type robot arm unit 10, but the present disclosure is not limited to this. In the present disclosure, the robot arm unit may be a horizontal multi-joint type robot arm unit.

[0075] In the above embodiment, an example has been shown in which the gear unit 24 is locked when performing a rotational operation by the control unit 40 generating torque in the drive unit 23, but the present disclosure is not limited to this. In the present disclosure, locking of the gear unit is not limited to locking the rotation of the drive unit by servoing through torque control. For example, the gear unit may be locked by stopping the rotation of the drive unit with an electromagnetic brake or a dynamic brake. Also, a brake may be arranged to directly limit the rotation of the gear unit, rather than the rotation of the drive unit.

[0076] In the above embodiment, the robot system 100 fastens the fastened member 2 from above with the screw member 1 as the fastening member, and supports the screw head 1a from below with the support member 25 when loosening the screw member 1, but the present disclosure is not limited to this. In the present disclosure, the robot system may perform at least one of the actions of tightening and loosening the fastening member from below, side, or obliquely with respect to the fastened member. Furthermore, when detecting whether the fastening member is stuck, the fastening member may be moved downward or sideways instead of upward while being supported by the support member.

[0077] The functions of the elements disclosed herein can be performed using circuits or processing circuits, including general purpose processors, special purpose processors, integrated circuits, Application Specific Integrated Circuits (ASICs), conventional circuits, and / or combinations thereof, configured or programmed to perform the disclosed functions. Processors are considered processing circuits or circuits because they include transistors and other circuits. In this disclosure, a circuit, unit, or means is hardware that performs the recited functions or hardware that is programmed to perform the recited functions. The hardware may be hardware disclosed herein or other known hardware that is programmed or configured to perform the recited functions. Where the hardware is a processor, which is considered a type of circuit, the circuit, means, or unit is a combination of hardware and software, and the software is used to configure the hardware and / or the processor.

[0078] [Aspects] It will be appreciated by those skilled in the art that the exemplary embodiments described above are examples of the following aspects.

[0079] (Aspect 1) an engaging member that engages with the fastening member; a robot arm portion to which the engaging member is attached and which rotates the engaging member; a control unit that performs a rotational operation to rotate the engaging member in a predetermined rotational direction by the robot arm unit with the engaging member engaged with the fastening member, and an idling operation to rotate the robot arm unit in a direction opposite to the predetermined rotational direction relative to the engaging member while rotating the engaging member relatively idly.

[0080] (Aspect 2) a fastening member rotation mechanism attached to the robot arm portion and including the engaging member; A drive unit that rotates the engagement member around a central axis of the fastening member, The control unit, during the idling operation, with the engaging member engaged with the fastening member, rotates the entire fastening member rotation mechanism in a direction opposite to the predetermined rotation direction using the robot arm unit, while rotating the engaging member relatively in the predetermined rotation direction using the drive unit at a rotational speed equivalent to the rotation by the robot arm unit.

[0081] (Aspect 3) The robot system according to aspect 1 or 2, wherein the control unit alternately performs the rotation operation and the idling operation while the engagement member is engaged with the fastening member.

[0082] (Aspect 4) a torque sensor for detecting a torque applied to the engaging member; A robot system according to any one of aspects 1 to 3, wherein the control unit performs the rotational movement until the torque detected by the torque sensor reaches a predetermined torque threshold value.

[0083] (Aspect 5) the fastening member rotation mechanism includes a gear portion that transmits a rotational force of the drive portion to the engagement member, The gear portion is During the rotational movement, it is locked, 3. The robot system of claim 2, wherein the robot system rotates together with the drive unit during the idling operation.

[0084] (Aspect 6) the fastening member rotation mechanism includes an elongated attachment member whose base end is attached to the robot arm portion, The drive unit is disposed at a center portion of the mounting member, 3. The robot system of claim 2, wherein the engagement member is disposed at a tip of the mounting member.

[0085] (Aspect 7) the fastening member rotation mechanism is disposed on the mounting member and includes a gear portion that transmits a rotational force of the drive portion to the engagement member, The gear portion is A drive gear that rotates around a rotation axis of the drive; An engagement portion gear that rotates around a rotation axis of the engagement member; 7. The robot system of claim 6, further comprising an intermediate gear disposed between the drive gear and the engagement gear, the intermediate gear transmitting rotation of the drive gear to the engagement gear.

[0086] (Aspect 8) 8. The robot system of claim 7, wherein a diameter of the drive gear and a diameter of the engagement gear are equal.

[0087] (Aspect 9) The robot system of claim 7 or 8, wherein a diameter of the engagement portion gear is smaller than a diameter of the intermediate gear.

[0088] (Aspect 10) The fastening member includes a screw member, A support member for supporting a screw head of the screw member; a moving mechanism that moves the support member in a direction toward or away from the fastening member, The control unit is a process of loosening the fastening member by the rotating operation and the idling operation in a state in which the engaging member is engaged with the fastening member; a process of moving the support member to a position supporting the screw head by the moving mechanism while the fastening member is loosened; A robot system according to any one of aspects 1 to 9, further comprising: a process of moving the fastening member by the robot arm unit while the screw head is supported by the support member.

[0089] (Aspect 11) A robot system according to any one of aspects 1 to 10, wherein the robot arm unit includes a vertical multi-joint type robot arm unit having a plurality of joint axes.

[0090] (Aspect 12) 3. The robot system according to aspect 2, wherein the control unit controls the drive unit as an external axis in cooperation with a joint axis of the robot arm unit.

[0091] (Aspect 13) a rotation operation of rotating the engaging member in a predetermined rotation direction by a robot arm unit that rotates the engaging member, the engaging member being attached in a state in which the engaging member is engaged with a fastening member; performing an idling operation in which the robot arm portion rotates relative to the engaging member in a direction opposite to the predetermined rotation direction while rotating the engaging member relatively idly. [Explanation of symbols]

[0092] 1 Screw members (fastening members) 1a Screw head 10 Robot arm section 20 Screw member rotation mechanism (fastening member rotation mechanism) 21 Mounting material 22 Engagement member 23 Drive unit 24 Gear section 24a Drive gear 24b Engagement gear 24c, 24c1, 24c2 intermediate gear 25 Support member 26 Moving mechanism 40 Control section 30 Force sensor (torque sensor) 100 Robot System

Claims

1. an engaging member that engages with the fastening member; a robot arm portion to which the engaging member is attached and which rotates the engaging member; a control unit that performs a rotational operation to rotate the engaging member in a predetermined rotational direction by the robot arm unit with the engaging member engaged with the fastening member, and an idling operation to rotate the robot arm unit in a direction opposite to the predetermined rotational direction relative to the engaging member while rotating the engaging member relatively idly.

2. a fastening member rotation mechanism attached to the robot arm portion and including the engaging member; A drive unit that rotates the engagement member around a central axis of the fastening member, 2. The robot system according to claim 1, wherein, during the idling operation, with the engaging member engaged with the fastening member, the control unit rotates the entire fastening member rotation mechanism in a direction opposite to the predetermined rotation direction using the robot arm unit, while causing the drive unit to rotate the engaging member relatively in the predetermined rotation direction at a rotational speed corresponding to the rotation by the robot arm unit.

3. The robot system according to claim 1 , wherein the control unit alternately executes the rotation operation and the idling operation in a state in which the engagement member is engaged with the fastening member.

4. a torque sensor for detecting a torque applied to the engaging member; The robot system according to claim 1 , wherein the control unit performs the rotational movement until the torque detected by the torque sensor reaches a predetermined torque threshold value.

5. the fastening member rotation mechanism includes a gear portion that transmits a rotational force of the drive portion to the engagement member, The gear portion is During the rotational movement, it is locked, The robot system according to claim 2 , wherein the robot system rotates together with the drive unit during the idling operation.

6. the fastening member rotation mechanism includes an elongated attachment member whose base end is attached to the robot arm portion, The drive unit is disposed at a center portion of the mounting member, The robot system according to claim 2 , wherein the engagement member is disposed at a tip of the attachment member.

7. the fastening member rotation mechanism is disposed on the mounting member and includes a gear portion that transmits a rotational force of the drive portion to the engagement member, The gear portion is A drive gear that rotates around a rotation axis of the drive; An engagement portion gear that rotates around a rotation axis of the engagement member; The robot system according to claim 6 , further comprising: an intermediate gear disposed between the drive unit gear and the engagement unit gear, the intermediate gear transmitting rotation of the drive unit gear to the engagement unit gear.

8. The robotic system of claim 7 , wherein a diameter of the drive gear and a diameter of the engagement gear are equal.

9. The robotic system of claim 7 , wherein a diameter of the engagement portion gear is smaller than a diameter of the intermediate gear.

10. The fastening member includes a screw member, A support member for supporting a screw head of the screw member; a moving mechanism that moves the support member in a direction toward or away from the fastening member, The control unit is a process of loosening the fastening member by the rotating operation and the idling operation in a state in which the engaging member is engaged with the fastening member; a process of moving the support member to a position supporting the screw head by the moving mechanism while the fastening member is loosened; The robot system according to claim 1 or 2, further comprising a process of moving the fastening member by the robot arm unit while the screw head is supported by the support member.

11. The robot system according to claim 1 or 2, wherein the robot arm unit includes a vertical articulated robot arm unit having a plurality of joint axes.

12. The robot system according to claim 2 , wherein the control unit controls the drive unit as an external axis in cooperation with a joint axis of the robot arm unit.

13. a rotation operation of rotating the engaging member in a predetermined rotation direction by a robot arm unit that rotates the engaging member, the engaging member being attached in a state in which the engaging member is engaged with a fastening member; performing an idling operation in which the robot arm portion rotates relative to the engaging member in a direction opposite to the predetermined rotation direction while rotating the engaging member relatively idly.

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