Robot device

Abstract

To prevent a processing part from scratching a surface when the surface including a large curvature part is continuously processed in a robot device.SOLUTION: In a drive part 5 of a robot device, a motor 7 generates a drive force for moving a processing part relative to a robot, and a drive force transmission part 8 transmits the drive force generated by the motor 7 to the processing part. The drive force transmission part 8 has: a pinion 13 assembled to an output shaft of the motor 7; and a rack 14 configured to engage with the pinion 13. The processing part is linearly driven in a direction in which the rack 14 is moved by rotation of the pinion 13 to cause the processing part to move relative to the robot. The structure prevents the processing part from scratching a surface when the surface including a large curvature part is continuously processed.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to a robot device that performs a predetermined process on a workpiece. [Background technology]

[0002] Conventionally, the above-mentioned robot device has been known to have a configuration including a processing unit, a driving unit, a sensor unit, and a control unit as described below, for the purpose of improving the quality of a workpiece after processing (see, for example, Patent Document 1). Here, the processing unit performs a predetermined process while exerting a force on the workpiece, and the drive unit increases or decreases the force that the processing unit exerts on the workpiece by driving the processing unit to move relative to the robot.

[0003] More specifically, the drive unit includes an electric motor and a ball screw, and converts torque generated by the electric motor into a linear force by the ball screw, and this linear force drives the processing unit to apply force to the workpiece. Furthermore, in the drive unit, the control unit controls the electric motor to increase or decrease the torque, thereby increasing or decreasing the force applied to the workpiece via the processing unit.

[0004] In addition, when the processing section is processing the workpiece, the sensing section senses the force that the processing section exerts on the workpiece and outputs a signal corresponding to this force, and the control section controls the electric motor according to the signal output by the sensing section. This allows the robot device to control the force that the processing section exerts on the workpiece while proceeding with processing by the processing section, thereby improving the quality of the workpiece after processing (hereinafter, control of the force that the processing section exerts on the workpiece may be referred to as "pressure control").

[0005] In recent years, for example, when polishing the surface of a workpiece, there has been a demand for polishing the following surfaces: That is, there has been a demand for continuously polishing a surface including a portion with a large curvature, such as a flat surface having a suddenly rising convex portion. However, when such a surface is continuously polished, the following problem occurs (hereinafter, a portion of the surface to be treated by the treatment section that has a large curvature may be referred to as a "large curvature portion").

[0006] That is, when the polishing tool as the processing section passes through the large curvature portion, the reaction force it receives from the surface temporarily becomes stronger than the force it exerts on the surface based on the pressure control, which results in a stronger force being exerted on the surface by the polishing tool, which may damage the surface.

[0007] To deal with such surface damage, it would be ideal to increase the responsiveness of the pressure control and, for example, reduce the force that the polishing tool exerts on the surface by rotating the electric motor in the reverse direction earlier. However, it is difficult to further increase the responsiveness of the pressure control, and it is considered necessary to take other measures. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Patent Publication No. 2021-053787 Summary of the Invention [Problem to be solved by the invention]

[0009] The present disclosure has been made to solve the above problems, and its purpose is to prevent a processing unit from damaging a surface when continuously processing a surface including a large curvature area in a robot device. [Means for solving the problem]

[0010] The robot device of the present disclosure includes the following processing unit and driving unit as effectors of the robot. That is, the processing unit performs a predetermined process while exerting a force on the workpiece, and the driving unit increases or decreases the force that the processing unit exerts on the workpiece by driving the processing unit to move relative to the robot. The driving unit also includes the following electric motor and driving force transmission unit. That is, the electric motor generates a driving force for moving the processing unit relative to the robot, and the driving force transmission unit transmits the driving force generated by the electric motor to the processing unit.

[0011] The driving force transmission unit has a pinion attached to the output shaft of the electric motor and a rack that meshes with the pinion, and moves the processing unit relative to the robot by linearly driving the processing unit in the direction in which the rack moves as the pinion rotates. As a result, according to the present disclosure, when a robotic device continuously processes a surface including a large curvature portion, it is possible to potentially prevent the processing portion from damaging the surface. [Brief description of the drawings]

[0012] [Figure 1] FIG. 2 is a perspective view of a main part of the robot device, showing the meshing between the pinion and the rack. [Diagram 2] FIG. 1 is an overall configuration diagram of a robot device. [Diagram 3] FIG. 2 is a side view of a main part of the robot device, showing the meshing between the pinion and the rack. [Figure 4] FIG. 2 is a front view of a main part of the robot device, showing the meshing between the pinion and the rack. [Diagram 5] FIG. 4 is an enlarged view of a main portion showing an engagement between a pinion and a rack. [Figure 6] FIG. 13 is an explanatory diagram showing a state in which the processing portion approaches a part of large curvature. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] The robot device according to the embodiment will be described based on the following examples. EXAMPLES

[0014] [Configuration of the embodiment] The configuration of a robot device 1 according to an embodiment will be described with reference to FIGS. The robot device 1 can be suitably used when continuously polishing a surface including a large curvature portion 2, such as a flat surface having a suddenly rising convex portion (see FIG. 6). The robot device 1 will be described in detail below.

[0015] The robot device 1 includes a processing unit 4 and a driving unit 5 as effectors of the robot 3. That is, the processing unit 4 performs a predetermined process while exerting a force on the workpiece 6, and the driving unit 5 increases or decreases the force that the processing unit 4 exerts on the workpiece 6 by driving the processing unit 4 to move relative to the robot 3. The robot 3 is a well-known six-axis vertical articulated type, and the processing unit 4 and the driving unit 5 are attached to the tip of the robot 3 (see FIG. 2).

[0016] The drive unit 5 also has an electric motor 7 and a drive force transmission unit 8. That is, the electric motor 7 generates a drive force for moving the processing unit 4 relative to the robot 3, and the drive force transmission unit 8 transmits the drive force generated by the electric motor 7 to the processing unit 4. Hereinafter, the electric motor 7 may be abbreviated to the motor 7. The motor 7 is, for example, a synchronous motor of a known configuration having a known position sensor.

[0017] Here, the processing section 4 has a well-known configuration including, for example, a polishing tool 10 for polishing the surface 6a of the workpiece 6, and an actuator for rotationally driving the polishing tool 10. The robot device 1 also includes a control panel as a control section 11 for controlling the operations of the robot 3, the processing section 4, the driving section 5, etc. The control section 11 then issues commands to the actuators of the robot 3, the processing section 4, the driving section 5, etc. to polish the surface 6a while rotating and moving the polishing tool 10 three-dimensionally.

[0018] In addition, the driving force transmission unit 8 has a pinion 13 attached to the output shaft of the motor 7, and a rack 14 that meshes with the pinion 13, and moves the processing unit 4 relative to the robot 3 by linearly driving the processing unit 4 in the direction in which the rack 14 moves due to rotation of the pinion 13.

[0019] Furthermore, the robot device 1 includes a sensory unit 15. That is, the sensory unit 15 senses the force that the processing unit 4 exerts on the workpiece 6 when the processing unit 4 performs a predetermined process on the workpiece 6, and outputs a signal according to the force. Then, the control unit 11 controls the motor 7 according to the signal output by the sensory unit 15, thereby performing pressure control.

[0020] The sensor 15 is assembled between the processor 4 and the rack 14 and is driven linearly in the same direction as the processor 4 and the rack 14 by the driving force generated by the motor 7 . Furthermore, the processing section 4 has the following first and second processing sections 4A and 4B. That is, the first processing section 4A applies a stronger force to the workpiece 6 when the rack 14 moves to one side of the moving directions, and the second processing section 4B applies a stronger force to the workpiece 6 when the rack 14 moves to the other side. Both the first and second processing sections 4A and 4B have a well-known configuration having the above-mentioned polishing tool 10 and the like.

[0021] The sensitive part 15 also has the following first and second sensitive parts 15A and 15B. That is, the first sensor 15A is assembled between the first processing unit 4A and the rack 14, senses the force that the first processing unit 4A exerts on the workpiece 6 when the first processing unit 4A processes the workpiece 6, and outputs a signal corresponding to this force. Then, the control unit 11 controls the motor 7 according to the signal output by the first sensor 15A, thereby executing pressure control for the first processing unit 4A.

[0022] The second sensory unit 15B is mounted between the second processing unit 4B and the rack 14, and senses the force that the second processing unit 4B exerts on the workpiece 6 when the second processing unit 4B processes the workpiece 6, and outputs a signal corresponding to this force. The control unit 11 then controls the motor 7 according to the signal output by the second sensory unit 15B, thereby controlling the pressure applied to the second processing unit 4B. Both the first and second sensory units 15A and 15B are, for example, well-known force sensors. The mounting structure of various components at the tip of the robot 3, including the processing unit 4, the driving unit 5, the sensor unit 15, etc., will be described below.

[0023] First, at the tip of the robot 3, the above-mentioned processing section 4, and the motor 7 and driving force transmission section 8 constituting the driving section 5, as well as the following protective structure 17 and sliding structure 18, etc. are provided. In the following description, a Cartesian coordinate system at the tip of the robot 3 is defined by taking the direction in which the rack 14 moves as the X direction, the direction of the output shaft of the motor 7 as the Y direction, and the direction perpendicular to both the X and Y directions as the Z direction.

[0024] First, the protective structure 17 surrounds the pinion 13 and the rack 14 to prevent, for example, foreign matter from becoming caught therein. More specifically, the protective structure 17 is composed of an enclosure 17A and a cover plate 17B as follows. Enclosure 17A encloses pinion 13 and rack 14 from one side and the other side in the X direction, the side opposite to the side where motor 7 is located in the Y direction, and one side and the other side in the Z direction.

[0025] Furthermore, inside enclosure 17A, rack 14 is fixed to the inside of a wall portion covering pinion 13 and rack 14 from one side in the Z direction. Furthermore, inside enclosure 17A, slider 18C, which will be described later, is fixed to a wall portion covering pinion 13 and rack 14 from the side opposite to the side on which motor 7 is located in the Y direction. This allows rack 14 and enclosure 17A to move relative to the tip of robot 3 and motor 7.

[0026] Further, the cover plate 17B rotatably holds the output shaft of the motor 7, and covers the pinion 13 and the rack 14 from the side where the motor 7 exists in the Y direction. Furthermore, the cover plate 17B is fixed to the connecting parts 20A and 20B. Here, the connecting parts 20A and 20B connect the mounting plate 21 (described later) and the motor 7 on one side and the other side in the Z direction, respectively. This prevents the cover plate 17B from changing its position three-dimensionally relative to the tip of the robot 3 and the motor 7.

[0027] Next, the slide structure 18 stabilizes the relative movement of the first and second processing sections 4A and 4B, the pinion 13, and the like with respect to the robot 3. More specifically, the sliding structure 18 is composed of the following rail 18R and three sliders 18A, 18B, 18C, etc. First, the rail 18R is provided linearly and fixed to a mounting plate 21 so as to face the X direction. Furthermore, the mounting plate 21 is fixed to the tip of the robot 3. Therefore, the rail 18R does not move relative to the robot 3. Furthermore, each of the sliders 18A to 18C has a recess into which the rail 18R fits, and with the rail 18R fitted, the sliders 18A to 18C can move linearly in the X direction.

[0028] Here, the sliders 18A to 18C are arranged in the order of sliders 18A, 18C, and 18B, and the enclosure 17A is fixed to the central slider 18C. The first processing unit 4A is fastened to the slider 18A on one side of the slider 18C in the X direction via a bridge 22A, and the second processing unit 4B is fastened to the slider 18B on the other side of the slider 18C via a bridge 22B.

[0029] Further, the first sensitive part 15A is sandwiched between the wall part on one side in the X direction of the enclosure 17A and the bridge 22A, connecting the enclosure 17A and the bridge 22A. Similarly, the second sensitive part 15B is sandwiched between the wall part on the other side of the enclosure 17A and the bridge 22B, connecting the enclosure 17A and the bridge 22B. Thereby, the first and second sensitive sections 15A and 15B are sensitive to the forces exerted on the workpiece 6 by the first and second processing sections 4A and 4B, respectively, and can output signals corresponding to these forces.

[0030] With the above-mentioned configuration, according to the robot device 1, the torque of the motor 7 is converted into a linear force by the meshing of the pinion 13 and the rack 14, and drives the processing section 4 in the X direction. For example, when the surface of the workpiece 6 is polished by the first processing unit 4A, the motor 7 is controlled to operate the rotation of the pinion 13, thereby moving the rack 14 in the X direction to control the pressure applied to the first processing unit 4A. At this time, the robot device 1 controls the motor 7 in response to a signal output from the first sensor 15A.

[0031] Similarly, when the surface of the workpiece 6 is polished by the second processing unit 4B, the motor 7 is controlled to operate the rotation of the pinion 13, thereby moving the rack 14 in the X direction to control the pressure applied to the second processing unit 4B. At this time, the robot device 1 controls the motor 7 in response to a signal output from the second sensor 15B.

[0032] In addition, the rack 14, the first and second sensitive parts 15A, 15B, the enclosure 17A, the sliders 18A-18C, and the bridges 22A, 22B move relative to the tip of the robot 3, the motor 7, etc. in the X direction together with the first and second processing parts 4A, 4B due to the linear force transmitted from the motor 7 via the pinion 13.

[0033] [Effects of the embodiment] The robot device 1 of the embodiment includes a processing unit 4 and a driving unit 5 as effectors of the robot 3. That is, the processing unit 4 performs a predetermined process while exerting a force on the workpiece 6, and the driving unit 5 increases or decreases the force that the processing unit 4 exerts on the workpiece 6 by driving the processing unit 4 to move relative to the robot 3. The driving unit 5 also includes a motor 7 and a driving force transmission unit 8 as described below. That is, the motor 7 generates a driving force for moving the processing unit 4 relative to the robot 3, and the driving force transmission unit 8 transmits the driving force generated by the motor 7 to the processing unit 4.

[0034] The driving force transmission unit 8 has a pinion 13 attached to the output shaft of the motor 7, and a rack 14 that meshes with the pinion 13, and moves the processing unit 4 relative to the robot 3 by linearly driving the processing unit 4 in the direction in which the rack 14 moves due to rotation of the pinion 13. This makes it possible to prevent the processing unit 4 from damaging the surface 6a when the surface 6a including the large curvature portion 2 is continuously processed by the robot device 1.

[0035] That is, the meshing structure of the pinion 13 and the rack 14 allows the reaction force acting on the processing portion 4 from the surface 6a to be largely released toward the output shaft of the motor 7, compared to the screw-on structure of a ball screw. Therefore, when the processing portion 4 passes through the large curvature portion 2, the reaction force is largely released toward the output shaft of the motor 7, so that the force that the processing portion 4 applies to the surface 6a can be largely reduced, and the processing portion 4 is less likely to damage the surface 6a. As described above, when the robot device 1 continuously processes the surface 6a including the large curvature portion 2, the processing section 4 can prevent the surface from being damaged.

[0036] The robot device 1 of the embodiment also includes a control unit 11 and a sensory unit 15. That is, the sensory unit 15 senses the force that the processing unit 4 exerts on the workpiece 6 when the processing unit 4 performs a predetermined process on the workpiece 6, and outputs a signal according to the force. The control unit 11 also controls the motor 7 according to the signal output by the sensory unit 15.

[0037] The sensor 15 is assembled between the processor 4 and the rack 14 and is driven linearly in the same direction as the processor 4 and the rack 14 by the driving force generated by the motor 7 . This allows the motor 7 to rotate in the reverse direction, for example, to easily release the reaction force toward the output shaft of the motor 7 when the processing section 4 passes through the large curvature section 2, by simultaneously controlling the pressure using the signal from the sensitive section 15. This further reduces the possibility that the processing section 4 will damage the surface.

[0038] Furthermore, according to the robot device 1 of the embodiment, the processing section 4 has a first processing section 4A in which the force applied to the workpiece 6 becomes stronger when the rack 14 moves to one side in the X direction, and a second processing section 4B in which the force applied to the workpiece 6 becomes stronger when the rack 14 moves to the other side. This allows the processing unit 4 to perform processing efficiently.

[0039] [Modifications] The embodiment discloses a specific example, and it goes without saying that the present invention is not limited to the embodiment. For example, according to the robot device 1 of the embodiment, the processing section 4 includes the first and second processing sections 4A and 4B, but the processing section 4 may be configured to include only one of them. Furthermore, although the robot device 1 of the embodiment includes the sensory unit 15, the sensory unit 15 may be omitted and the pressure control using the signal from the sensory unit 15 may not be executed. [Explanation of symbols]

[0040] REFERENCE SIGNS LIST 1 robot device 3 robot 4 processing section 5 drive section 6 workpiece 7 motor (electric motor) 8 drive force transmission section 13 pinion 14 rack

Claims

1. As a robot effector, A processing section that applies a predetermined process to the workpiece while exerting a force thereon; a drive unit that drives the processing unit to move relative to the robot, thereby increasing or decreasing the force that the processing unit exerts on the workpiece, The drive unit is an electric motor that generates a driving force for moving the processing unit relative to the robot; a driving force transmission unit that transmits a driving force generated by the electric motor to the processing unit, This driving force transmission unit is A pinion is attached to the output shaft of the electric motor, and a rack is engaged with the pinion. A robot device characterized in that the processing section is moved relative to the robot by linearly driving the processing section in a direction in which the rack moves due to rotation of the pinion.

2. 2. The robot device according to claim 1, A sensor that senses a force exerted by the processing unit on the workpiece when the processing unit performs the predetermined processing on the workpiece and outputs a signal corresponding to the force; a control unit that controls the electric motor in response to a signal output by the sensor unit, The robot device is characterized in that the sensor unit is assembled between the processing unit and the rack, and is driven linearly in the same direction as the processing unit and the rack by the driving force generated by the electric motor.

3. 2. The robot device according to claim 1, The robot device is characterized in that the processing section has a first processing section that applies a stronger force to the workpiece when the rack moves to one side of the directions in which the rack moves, and a second processing section that applies a stronger force to the workpiece when the rack moves to the other side.

Images