robotic 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 the processed workpiece (see, for example, Patent Document 1). Here, 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.

[0003] The drive unit, more specifically, includes an electric motor and a ball screw, and converts torque generated by the electric motor into a linear force using the ball screw, which then drives the processing unit and exerts a force on 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 exerted on 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 applies to 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 applies to the workpiece while proceeding with processing by the processing section, thereby improving the quality of the workpiece after processing (hereinafter, controlling the force that the processing section applies to 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 surfaces that include portions with large curvatures, such as flat surfaces with suddenly rising convex portions. However, when such a surface is continuously polished, the following problem occurs (hereinafter, a portion of the surface to be processed by the processing section that has a large curvature may be referred to as a "large curvature portion").

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

[0007] To address such surface damage, it would be ideal to increase the responsiveness of the pressure control, for example by quickly reversing the rotation of the electric motor to weaken the force that the polishing tool exerts on the surface. However, it is difficult to further increase the responsiveness of the pressure control, and it is thought that additional measures will be necessary. [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-mentioned problems, and its purpose is to prevent damage to surfaces by processing units when continuously processing surfaces including areas of high curvature in a robotic 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 a 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 driving the processing unit linearly in the direction in which the rack moves as the pinion rotates. The processing unit also has a first processing unit that applies a stronger force to the workpiece when the rack moves to one side of the direction of movement, and a second processing unit that applies a stronger force to the workpiece when the rack moves to the other side. 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 unit from damaging the surface. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a perspective view of a main part of a robot device, showing the meshing between a pinion and a rack. [Figure 2] FIG. 1 is an overall configuration diagram of a robot device. [Figure 3] FIG. 1 is a side view of a main part of a robot device, showing the meshing between a pinion and a rack. [Figure 4] FIG. 1 is a front view of a main part of a robot device, showing the meshing between a pinion and a rack. [Figure 5] FIG. 4 is an enlarged view of a main part showing the meshing between the pinion and the rack. [Figure 6] FIG. 10 is an explanatory diagram showing a state in which the processing portion approaches a large curvature portion. DETAILED DESCRIPTION OF THE INVENTION

[0013] The robot device of the embodiment will be described based on the following examples. [Example]

[0014] [Configuration of the Example] The configuration of a robot device 1 according to the 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 sharply 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 robot, 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 that polishes the surface 6a of the workpiece 6, and an actuator that rotates and drives the polishing tool 10. The robot device 1 also includes a control panel as a control section 11 that controls the operations of the robot 3, the processing section 4, the drive section 5, etc. The control section 11 then issues commands to the actuators of the robot 3, the processing section 4, the drive section 5, etc., to rotate and move the polishing tool 10 three-dimensionally, thereby polishing the surface 6a.

[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 driving the processing unit 4 linearly in the direction in which the rack 14 moves due to the rotation of the pinion 13.

[0019] Furthermore, the robot device 1 includes the following sensory unit 15. That is, when the processing unit 4 performs a predetermined process on the workpiece 6, the sensory unit 15 senses the force that the processing unit 4 applies to 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 sensory unit 15, thereby performing pressure force control.

[0020] The sensitive part 15 is assembled between the processing part 4 and the rack 14 and is driven linearly in the same direction as the processing part 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, 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 including the 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, and senses the force that the first processing unit 4A applies to 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 controlling the pressure applied to the first processing unit 4A.

[0022] The second sensor 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 while the second processing unit 4B is processing 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 sensor 15B, thereby controlling the pressure applied to the second processing unit 4B. Note that both the first and second sensor 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 unit 4, the motor 7 and driving force transmission unit 8 constituting the drive unit 5, as well as the following protective structure 17, slide structure 18, etc. are provided. In the following description, a Cartesian coordinate system at the tip of the robot 3 is defined by defining 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 encloses the pinion 13 and the rack 14, thereby preventing, for example, foreign matter from entering. Bite This is to prevent the device from being immersed in water. More specifically, the protective structure 17 is composed of the following enclosure 17A and cover plate 17B. Enclosure 17A encloses pinion 13 and rack 14 from one side and the other 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 in the Z direction.

[0025] Furthermore, rack 14 is fixed to the inside of a wall portion of enclosure 17A that covers pinion 13 and rack 14 from one side in the Z direction. Furthermore, slider 18C, which will be described later, is fixed to a wall portion of enclosure 17A that covers 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] 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 is located in the Y direction. Furthermore, cover plate 17B is fixed to connecting portions 20A and 20B. Here, connecting portions 20A and 20B connect a mounting plate 21 (described later) to motor 7 on one side and the other side in the Z direction, respectively. This prevents cover plate 17B from changing its position three-dimensionally relative to the tip of robot 3 and motor 7.

[0027] Next, the slide structure 18 is connected to the first and second processing sections 4A and 4B. Rack 14 These stabilize the relative movement of the robot 3. More specifically, the sliding structure 18 is composed of the following rail 18R and three sliders 18A, 18B, 18C, etc. Rail 18R is provided linearly and fixed to a mounting plate 21 so as to face the X direction. Mounting plate 21 is also fixed to the tip of robot 3. For this reason, rail 18R does not move relative to robot 3. Furthermore, sliders 18A to 18C each have a recess into which rail 18R fits, and with rail 18R fitted, they 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. Furthermore, the first processing unit 4A is fastened via a bridge 22A to the slider 18A located on one side of the slider 18C in the X direction, and the second processing unit 4B is fastened via a bridge 22B to the slider 18B located on the other side of the slider 18C.

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

[0030] With the above-described configuration, the robot device 1 converts the torque of the motor 7 into a linear force due to the meshing of the pinion 13 and the rack 14, thereby driving the processing unit 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 and controlling 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 and controlling 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] The rack 14, the first and second sensitive parts 15A, 15B, the enclosure 17A, the sliders 18A to 18C, and the bridges 22A, 22B, together with the first and second processing parts 4A, 4B, move relative to the tip of the robot 3, the motor 7, etc. in the X direction due to the linear force transmitted from the motor 7 via the pinion 13.

[0033] [Effects of the Example] 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 driving the processing unit 4 linearly 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 robot device 1 continuously processes the surface 6a including the large curvature portion 2.

[0035] That is, the pinion 13 and the rack 14 Bite The interlocking structure makes it much easier to dissipate the reaction force acting from the surface 6a to the processing section 4 toward the output shaft of the motor 7 than with the threaded structure of a ball screw. Therefore, when the processing section 4 passes through the large curvature section 2, the reaction force is largely dissipated toward the output shaft of the motor 7, which significantly reduces the force that the processing section 4 applies to the surface 6a, making it less likely that the processing section 4 will damage the surface 6a. As described above, when the robot device 1 continuously processes the surface 6a including the large curvature portion 2, it is possible to prevent the processing unit 4 from damaging the surface.

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

[0037] The sensitive part 15 is assembled between the processing part 4 and the rack 14 and is driven linearly in the same direction as the processing part 4 and the rack 14 by the driving force generated by the motor 7 . As a result, by simultaneously controlling the pressure using the signal from the sensitive part 15, when the processing part 4 passes through the large curvature part 2, it is possible to, for example, reverse the rotation of the motor 7 to make it easier to release the reaction force toward the output shaft of the motor 7. This makes it possible to further reduce the possibility that the processing part 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 exerted on 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 exerted on the workpiece 6 becomes stronger when the rack 14 moves to the other side. This allows the processing unit 4 to perform the processing efficiently.

[0039] [Modification] The embodiment discloses a specific example, and it goes without saying that the present invention is not limited to the embodiment. for example ,fruit Although the robot device 1 of the embodiment is provided with the sensor unit 15, the sensor unit 15 may be omitted and pressure force control using the signal from the sensor unit 15 may not be performed. [Explanation of symbols]

[0040] 1 Robot device 3 Robot 4 Processing unit 5 Driving unit 6 Workpiece 6a surface 7 Motor (electric motor) 8 Driving force transmission section 10 Polishing tools 11 Control Unit 13 Pinion 14 Rack

Claims

[Claim 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 increases or decreases the force that the processing unit applies to the workpiece by driving the processing unit to move relative to the robot, 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 the driving force generated by the electric motor to the processing unit, This driving force transmission unit is a pinion attached to the output shaft of the electric motor and a rack meshing with the pinion; The processing unit is linearly driven in a direction in which the rack moves due to rotation of the pinion, thereby moving the processing unit relative to the robot; The processing unit is a robot device characterized in that it has a first processing unit that increases the force applied to the workpiece when the rack moves to one side of the direction of movement, and a second processing unit that increases the force applied to the workpiece when the rack moves to the other side.

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