Method for adjusting the rotation axis of a machining head module, multi-axis robot, and machining head.

Abstract

The process of adjusting the rotation axis of the machining head to be perpendicular to the surface to be drilled is designed to reduce the time required. [Solution] The machining head module 16 is attached to the articulated arm 12 and includes a drill 33 that drills into the workpiece while rotating, a machining head 17 which is cylindrical in shape concentric with the drill 33 and has a foot 40 that contacts the drilling target surface S of the workpiece W with an opening edge 41 at its tip, a control device 46 that controls the machining head 17, a force sensor 45 that detects the reaction force when the opening edge 41 presses against the drilling target surface S, and a robot control unit 50 that equalizes the reaction force from the drilling target surface S. Based on the detection information from the force sensor 45, the robot control unit 50 controls the movement of the articulated arm 12 so that the pressing portion 43 on the opening edge 41 against the drilling target surface S is displaced in the circumferential direction and the area of ​​the pressing portion 43 expands in the circumferential direction.

Description

Technical Field

[0001] The present invention relates to a processing head module, a multi-axis robot, and a method for adjusting the rotation axis of a processing head.

Background Art

[0002] Patent Document 1 discloses a robot having a robot arm, a drilling device attached to the tip of the robot arm, and a robot control unit for controlling the robot arm. The drilling device has a drill for forming a through hole in a workpiece. The drill is rotationally driven while being held by a spindle, and the spindle strokes in the advancing and retreating directions with respect to the workpiece. When forming a through hole, the robot control unit controls the robot arm to determine the direction of the spindle with respect to the workpiece. A force sensor is used as means for adjusting the stroke direction of the spindle with respect to the workpiece. The force sensor measures the moment around two axes on a two-dimensional plane orthogonal to the stroke direction as the reaction force from the workpiece to the drill, and the robot control unit controls the robot arm so that the moment around these two axes becomes zero.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When the direction of the spindle is inclined in an oblique direction with respect to both one axis and the other axis, in order to make the moments around both axes zero, it is necessary to repeatedly perform the steps of tilting the spindle in a seesaw shape around one axis and tilting the spindle in a seesaw shape around the other axis many times. Therefore, the robot described in Patent Document 1 has a problem that it takes time to adjust the direction of the spindle.

[0005] This disclosure was completed based on the circumstances described above, and aims to reduce the time required in the process of adjusting the rotation axis of the machining head to be perpendicular to the surface to be drilled. [Means for solving the problem]

[0006] The machining head module of the first disclosure is A machining head having a drill that is attached to a multi-joint arm of a multi-axis robot and drills a workpiece while rotating, and a foot that is cylindrical in shape concentric with the drill and has an open edge at the tip that contacts the surface of the workpiece to be drilled, A control device for controlling the processing head, A force sensor that detects the reaction force when the opening edge presses against the surface to be drilled, The robot includes a robot control unit that equalizes the reaction force from the surface to be drilled, Based on the detection information from the force sensor, the robot control unit controls the movement of the articulated arm such that the pressing portion on the surface to be drilled at the opening edge is displaced in the circumferential direction, and the area of ​​the pressing portion expands in the circumferential direction.

[0007] The multi-axis robot in the second disclosure is A multi-joint arm in which multiple arms are connected in a way that allows for relative displacement, A machining head having a drill that drills a workpiece while rotating, wherein the direction of the rotation axis of the drill changes by the movement of the articulated arm, A control device for controlling the processing head, The machining head comprises a foot that is cylindrical in shape and concentric with the drill, and whose opening edge at the tip contacts the surface of the workpiece to be drilled, A force sensor that detects the reaction force when the opening edge presses against the surface to be drilled, The robot includes a robot control unit that equalizes the reaction force from the surface to be drilled, Based on the detection information from the force sensor, the robot control unit controls the movement of the articulated arm such that the pressing portion on the surface to be drilled at the opening edge is displaced in the circumferential direction, and the area of ​​the pressing portion expands in the circumferential direction.

[0008] The third disclosure describes a method for adjusting the rotation axis of a machining head, A multi-joint arm in which multiple arms are connected in a way that allows for relative displacement, A machining head having a drill that drills a workpiece while rotating, wherein the direction of the rotation axis of the drill changes by the movement of the articulated arm, A control device for controlling the processing head, The machining head comprises a foot that is cylindrical in shape and concentric with the drill, and whose opening edge at the tip contacts the surface of the workpiece to be drilled, A force sensor that detects the reaction force when the opening edge presses against the surface to be drilled, A robot control unit is provided to equalize the reaction force from the surface to be drilled, Based on the detection information from the force sensor, the robot control unit controls the movement of the articulated arm such that the pressing portion on the drilling target surface at the opening edge is displaced in the circumferential direction and the area of ​​the pressing portion expands in the circumferential direction. [Effects of the Invention]

[0009] According to the first, second, and third disclosures, time can be reduced in the process of adjusting the rotation axis of the processing head so that it is perpendicular to the surface to be drilled. [Brief explanation of the drawing]

[0010] [Figure 1] This is a perspective view of the multi-axis robot of Embodiment 1. [Figure 2] This is a perspective view of the machining head, seen from a diagonal downward angle. [Figure 3] This is a side cross-sectional view showing the state where the rotation axis of the machining head is perpendicular to the surface to be drilled, and the foot is in contact with the surface to be drilled. [Figure 4]It is a side sectional view showing the state where the workpiece is drilled by a drill. [Figure 5] It is a plan sectional view of the processing head. [Figure 6] It is a side sectional view showing the state where the rotation axis of the processing head is oblique to the drilling target surface and the foot presses the drilling target surface. [Figure 7] It is a block diagram showing a configuration for controlling the movement of the multi-joint arm so that the rotation axis of the processing head is perpendicular to the drilling target surface.

Embodiments for Carrying out the Invention

[0011] Here, desirable exemplary embodiments of the present disclosure are shown. Combinations of the following multiple exemplary embodiments arbitrarily within a range that does not cause contradictions are also included in the embodiments for carrying out the invention.

[0012] The processing head module of the first disclosure is (1) A drill attached to a multi-joint arm constituting a multi-axis robot and drilling the workpiece while rotating, a processing head having a cylindrical shape concentric with the drill and a foot whose leading opening edge abuts the drilling target surface of the workpiece, a control device for controlling the processing head, a force sensor for detecting a reaction force when the opening edge presses the drilling target surface, and a robot control unit for leveling the reaction force from the drilling target surface. The robot control unit controls the movement of the multi-joint arm based on the detection information of the force sensor so that the pressing portion of the opening edge on the drilling target surface is displaced in the circumferential direction and the area of the pressing portion expands in the circumferential direction.

[0013] According to the first disclosure, when the robot control unit controls the movement of the articulated arm, the machining head changes its posture so that the pressing part on the drilling target surface at the opening edge of the foot is displaced in the circumferential direction, and the rotation axis of the drill moves in a conical shape by gyrating in a precession motion. In the process of the pressing part on the drilling target surface at the opening edge being displaced in the circumferential direction, the robot control unit corrects the movement of the articulated arm based on the detection information from the force sensor. By correcting the movement of the articulated arm, the swirling movement of the rotation axis gradually reduces the swirling diameter, the reaction force is leveled, and the area of the pressing part at the opening edge expands in the circumferential direction. When the reaction force is leveled over the entire circumference of the opening edge, the adjustment of the direction of the rotation axis is completed, and the rotation axis becomes perpendicular to the drilling target surface. According to the first disclosure, since the direction of the rotation axis is adjusted while the machining head is swirling in a spiral shape, compared with repeating a seesaw-like movement to make the moments around two axes with different directions zero, time can be shortened.

[0014] (2) In (1), it is preferable that the robot control unit controls the movement of the articulated arm so that the pressing part always remains in contact with the drilling target surface. According to this configuration, compared with the case of repeating the operation of separating the pressing part from the drilling target surface and the operation of pressing the pressing part against the drilling target surface, the time required for adjustment can be shortened.

[0015] (3) In (1) or (2), it is preferable that the robot control unit controls the movement of the articulated arm so that the pressing part is displaced only in one direction in the circumferential direction of the opening edge. According to this configuration, compared with the case where the pressing part is displaced back and forth in the circumferential direction of the opening edge, the time required for adjustment can be shortened.

[0016] (4) In (1) or (2), it is preferable that the force sensor is a six-axis force sensor. According to this configuration, the direction of the rotation axis can be adjusted with higher precision.

[0017] The multi-axis robot in the second disclosure is (5) The machine comprises a multi-joint arm having multiple arms connected so as to be relatively displaceable, a drill that drills a workpiece while rotating, the direction of the rotation axis of the drill changes with the movement of the multi-joint arm, a foot which constitutes the machine, is cylindrical in shape concentric with the drill and has an opening edge at the tip that contacts the surface of the workpiece to be drilled, a control device for controlling the machine, a force sensor for detecting the reaction force when the opening edge presses the surface to be drilled, and a robot control unit for leveling the reaction force from the surface to be drilled, wherein the robot control unit controls the movement of the multi-joint arm based on the detection information of the force sensor so that the pressing portion of the opening edge against the surface to be drilled is displaced in the circumferential direction and the area of ​​the pressing portion expands in the circumferential direction. According to the second disclosure, the direction of the rotation axis is adjusted while the machine is rotated in a spiral shape, so, as with the first disclosure, the time required for adjusting the rotation axis of the machine to be perpendicular to the surface to be drilled can be reduced.

[0018] In (6)(5), it is preferable that the force sensor is located at the tip of the articulated arm. In the shaft structure connecting the arms, there is clearance between the gears that mesh with each other, so it is unavoidable that the arms may be slightly displaced relative to each other. Therefore, if the force sensor is located at a position other than the tip of the articulated arm, the reaction force will be transmitted to the force sensor via the shaft structure, so it is unavoidable that the accuracy of the force sensor's detection information will be reduced. As a countermeasure, the force sensor is located at the tip of the articulated arm. With this configuration, the reaction force from the workpiece is transmitted to the force sensor without going through the shaft structure of the articulated arm, so the detection accuracy of the force sensor is improved.

[0019] The third disclosure describes a method for adjusting the rotation axis of a machining head, (7) A multi-joint arm having multiple arms connected so as to be relatively displaceable, a drill that drills a workpiece while rotating, the direction of the rotation axis of the drill changes with the movement of the multi-joint arm, a foot which constitutes the processing head and is cylindrical in shape concentric with the drill, with the opening edge of the tip in contact with the surface to be drilled on the workpiece, a control device for controlling the processing head, a force sensor for detecting the reaction force when the opening edge presses the surface to be drilled, and a robot control unit for leveling the reaction force from the surface to be drilled. Based on the detection information from the force sensor, the robot control unit controls the movement of the multi-joint arm so that the pressing portion of the opening edge against the surface to be drilled is displaced in the circumferential direction, and the area of ​​the pressing portion expands in the circumferential direction. According to the third disclosure, the direction of the rotation axis is adjusted while the processing head is rotated in a spiral, so, as with the first and second disclosures, time can be reduced in the process of adjusting the rotation axis of the processing head to be perpendicular to the surface to be drilled.

[0020] <Embodiment 1> Embodiment 1, which embodies the present disclosure, will be described with reference to Figures 1 to 7. However, the present invention is not limited to these examples, and is intended to be included in the claims, with all modifications within the meaning and scope of equivalence to the claims. In Embodiment 1, the front-to-back direction is defined as direction F in Figures 1 to 6. The up-and-down direction is defined as direction H in Figures 1 to 4 and 6. The left-to-right direction is defined as direction R in Figures 1, 2 and 5.

[0021] The multi-axis robot A of this embodiment 1 comprises a robot body 10, a control device 46, and a robot control unit 50. The robot body 10 includes a base 11, a multi-joint arm 12, a plurality of arm servo motors 15, and a machining head module 16. The base 11 is fixed to the floor surface. The multi-joint arm 12 is constructed by connecting a plurality of arms 13 in series via joints 14. The connected arms 13 can be displaced (rotated) relative to each other by the arm servo motors 15. The base end of the multi-joint arm 12 is supported on the upper surface of the base 11 so as to be able to rotate horizontally. The position, movement speed, and orientation of the tip 12A of the multi-joint arm 12 in three dimensions are controlled by the operation of at least one arm servo motor 15. The operating status of each arm servo motor 15 is detected by a detection part such as an encoder built into each arm servo motor 15.

[0022] The joints 14 connecting the arms 13 are equipped with reduction gears (not shown) for transmitting the driving force of the arm servo motors 15 to each arm 13. A small clearance (play) is necessary between the reduction gears to ensure smooth rotation of the reduction gears. Therefore, even when the multi-joint arm 12 is not being driven, a slight relative displacement may occur between the arms 13. Consequently, it is difficult to control the position, movement speed, and direction of the tip 12A of the multi-joint arm 12 with high precision.

[0023] The machining head module 16 comprises a machining head 17 and a force sensor 45. The machining head 17 is attached to the tip 12A of the articulated arm 12. The machining head 17 comprises a frame 18 attached to the tip 12A of the articulated arm 12, an actuator 24 attached to the frame 18, a spindle 30 attached to the actuator 24, and a drill 33 for drilling that is rotationally driven by the spindle 30.

[0024] The structure of the machining head 17 will now be described assuming that the rotation axis 34 of the drill 33 is facing in the vertical direction. The frame 18 has a horizontal bottom plate portion 19 that forms a rectangle in a plan view when the machining head 17 is viewed from above, four vertical plate portions 20 rising from the outer edge of the bottom plate portion 19 on the front, back, left, and right sides, and a top plate portion 21 that is rectangular in plan view and connected to the upper edges of the four vertical plate portions 20. The frame 18 is fixed to the tip portion 12A of the articulated arm 12 via a force sensor 45 fixed to the upper surface of the top plate portion 21.

[0025] The actuator 24 is attached to the rear plate portion 20R of the four vertical plate portions 20. The actuator 24 comprises a male threaded rod 25 whose axis is oriented parallel to the rotation axis 34, a guide groove 26 extending parallel to the male threaded rod 25, an actuator servo motor 27 that rotates the male threaded rod 25 in both forward and reverse directions, and a lifting member 28 having a female threaded hole 29. The lifting member 28 is fitted into the guide groove 26 in a non-rotatable state with the female threaded hole 29 fitted to the male threaded rod 25. When the actuator servo motor 27 is driven to rotate the male threaded rod 25, the lifting member 28 slides in a direction parallel to the rotation axis 34 of the drill 33 (up and down direction) while sliding against the guide groove 26. The operating status of the actuator servo motor 27 is detected by a detection part such as an encoder built into the actuator servo motor 27.

[0026] A spindle 30 is attached to the lifting member 28. The spindle 30 is driven to move up and down by an actuator servo motor 27. The spindle 30 includes a spindle servo motor 31, a chuck 32, and a drill 33. The spindle servo motor 31 is fixed to the lifting member 28 and moves up and down together with the lifting member 28. A chuck 32, which is rotationally driven by the spindle servo motor 31, is provided at the lower end of the spindle servo motor 31. The drill 33 is detachably attached to the chuck 32. The drill 33 is an elongated member with its rotation axis 34 oriented vertically and protrudes downward from the chuck 32. The operating status of the spindle servo motor 31 is detected by a detection part such as an encoder built into the spindle servo motor 31.

[0027] A communication hole 35, which opens in a circular shape in plan view, is formed in the bottom plate portion 19 of the frame 18. A duct member 36 is fixed to the lower surface of the bottom plate portion 19. The duct member 36 has a cylindrical portion 37 with its axis oriented in the vertical direction, and a discharge portion 38 that extends diagonally upward and forward from the outer circumferential surface of the cylindrical portion 37. The upper end of the cylindrical portion 37 is in coaxial communication with the communication hole 35. A cylindrical foot 40 is detachably attached to the lower end edge of the cylindrical portion 37.

[0028] The foot 40 is a cylindrical component made of synthetic resin. The foot 40 is positioned concentrically with the rotation axis 34 of the drill 33, with its axis oriented vertically. The lower edge of the foot 40 functions as a circular opening 41 to receive the reaction force when the foot 40 is pressed against the workpiece W. The lower surface of the opening 41 functions as a contact surface 42 consisting of a plane perpendicular to the axis of the foot 40, i.e., the rotation axis 34 of the drill 33.

[0029] The chuck 32 of the spindle 30 is positioned at a height that penetrates the communication hole 35. When the spindle 30 is at its uppermost position in the lifting stroke, the lower end of the drill 33 is above the lower end of the foot 40. When the spindle 30 is at its lowermost position in the lifting stroke, the lower end of the drill 33 is below the lower end of the foot 40.

[0030] The force sensor 45 consists of a 6-axis force sensor 45 that simultaneously detects the loads in the X, Y, and Z axes, and the moments around each of the X, Y, and Z axes. The force sensor 45 is installed such that the X and Y axes are perpendicular to the rotation axis 34 of the drill 33, and the Z axis is coaxial with the rotation axis 34 of the drill 33. The force sensor 45 is mounted between the tip 12A of the articulated arm 12 and the machining head 17. The force sensor 45 detects the reaction force acting on the foot 40 from the drilling surface S of the workpiece W when the foot 40 of the machining head 17 is pressed against the drilling surface S of the workpiece W. The detected reaction force values ​​are input to the robot control unit 50 as loads in each axial direction and moments around each axis, or are input to the control device 46, which will be described later, via the robot control unit 50.

[0031] The control device 46 is located separately from the robot body 10. The control device 46 includes a PLC (Programmable Logic Controller) 47, an actuator servo amplifier 48, and a spindle servo amplifier 49. The actuator servo amplifier 48 receives commands from the PLC 47 and supplies the necessary power to the actuator servo motor 27 to execute the task. The spindle servo amplifier 49 supplies the necessary power to the spindle servo motor 31 to execute the task of the command received from the PLC 47.

[0032] The actuator servo amplifier 48 receives feedback signals indicating the operating status of the actuator servo motor 27. The spindle servo amplifier 49 receives feedback signals indicating the operating status of the spindle servo motor 31. The control device 46 controls the actuator servo motor 27 of the actuator 24 and the spindle servo motor 31 based on the feedback signals returned to the actuator servo amplifier 48 and the spindle servo amplifier 49.

[0033] The control device 46 controls the actuator servo motor 27 and the spindle servo motor 31 based on detection information input from the force sensor 45 via the robot control unit 50, and also sends commands to the robot control unit 50. When the contact surface 42 of the opening edge 41 of the foot 40 comes into contact with the drilling target surface S of the workpiece W, the control device 46 controls the movement of the articulated arm 12 based on detection information output from the force sensor 45 so that the rotation axis 34 of the drill 33 is oriented perpendicular to the drilling target surface S.

[0034] The robot control unit 50 is located separately from the robot body 10 and the control device 46. The robot control unit 50 has a servo amplifier (not shown). This servo amplifier receives commands from the control device 46 and data from the force sensor 45, and supplies the necessary power to the arm servo motors 15 to perform tasks. The operating status of each arm servo motor 15 is returned to the servo amplifier of the robot control unit 50 as a feedback signal. Based on this feedback signal, the robot control unit 50 controls each arm servo motor 15.

[0035] Next, the process of forming a through hole H perpendicular to the drilling surface S in a plate-shaped workpiece W, with the workpiece W positioned with its drilling surface S (plane) facing horizontally upward, will be described. First, the actuator servo motor 27 is activated to move the drill 33 upward, and the lower end (tip) of the drill 33 is moved to a position above the opening edge 41 (contact surface 42) of the foot 40. Next, the arm servo motor 15 is driven to bring the contact surface 42 (opening edge 41) of the foot 40 into contact with the drilling surface S from above in a pressing state.

[0036] In this case, as shown in Figure 6, if the rotation axis 34 of the drill 33 (the central axis of the foot 40) is oblique to the normal (not shown) perpendicular to the surface to be drilled S, then only a portion of the circumferential part of the opening edge 41 (contact surface 42) of the foot 40 will contact the surface to be drilled S. In this state, the reaction force acting from the workpiece W (surface to be drilled S) on the foot 40 is not uniform over the entire circumference, so the force sensor 45 detects the reaction force in at least one of the X-axis and Y-axis directions, and also detects the moment around at least one of the X-axis and Y-axis directions.

[0037] When detection information from the force sensor 45 is input to the control device 46, the control device 46 controls the servo motor 15 for the arm based on the detection information from the force sensor 45, thereby controlling the movement of each arm 13 of the articulated arm 12. By controlling the movement of the articulated arm 12, the orientation of the rotation axis 34 is corrected while the machining head 17 (foot 40) is rotated. Specifically, the rotation axis 34 of the drill 33 is rotated like the precession of a spinning top, while the detection values ​​from the force sensor 45 are leveled. In this correction process (leveling process), the pressing portion 43 on the contact surface 42 of the foot 40 against the drilling target surface S is displaced in the circumferential direction, and the contact area of ​​the pressing portion 43 against the drilling target surface S expands in the circumferential direction.

[0038] When the rotation axis 34 becomes perpendicular to the drilling target surface S, the forces (loads) applied in the X and Y axes, based on the center point of the rotation axis 34, become symmetrical, and at the same time, the moments around the X axis and Y axis become zero. When the forces (loads) applied in the X and Y axes become symmetrical, the load on the positive side of the axis and the load on the negative side of the axis become equal, based on the center point of the rotation axis 34. As a result, the opening edge 41 (contact surface 42) contacts the foot 40 with a uniform force over its entire circumference, and the correction process for the rotation axis 34 is completed. After this, if necessary, the drilling position is adjusted by moving the machining head 17 by controlling the articulated arm 12 with the control device 46. The machining head 17 maintains the orientation of its rotation axis 34 relative to the drilling surface S, and after moving away from the workpiece W (drilling surface S), it moves so that, in a plan view, the rotation axis 34 coincides with a predetermined drilling position on the drilling surface S. When adjusting the drilling position, it is preferable to correct the spatial coordinate position using external equipment (laser tracker or stereo camera).

[0039] With the above steps completed, the process of correcting the orientation of the rotation axis 34 of the drill 33 relative to the workpiece W (the surface to be drilled S) and the preparation for the drilling process are completed. Next, the actuator servo motor 27 and the spindle servo motor 31 are started to rotate the drill 33 and lower the actuator 24. As a result, the drill 33 forms a through hole H in the workpiece W with its rotation axis 34 oriented perpendicular to the surface to be drilled S.

[0040] The multi-axis robot A of this embodiment 1 comprises a multi-joint arm 12, a machining head module 16 attached to the tip 12A of the multi-joint arm 12, a control device 46, and a robot control unit 50. The machining head module 16 comprises a machining head 17 and a force sensor 45. The machining head 17 has a drill 33 that drills into the workpiece W while rotating, and a foot 40 that is cylindrical and concentric with the drill 33, with an opening edge 41 at its tip that contacts the surface S of the workpiece W to be drilled. The force sensor 45 detects the reaction force when the opening edge 41 presses against the surface S to be drilled. The control device 46 controls the machining head 17. The robot control unit 50 has a function to equalize the reaction force from the surface S to be drilled. The robot control unit 50 controls the movement of the multi-joint arm 12 based on the detection information from the force sensor 45. By controlling the movement of the articulated arm 12, the pressing portion 43 on the opening edge 41 against the surface S to be drilled is displaced in the circumferential direction, and the area of ​​the pressing portion 43 expands in the circumferential direction.

[0041] According to the multi-axis robot A, machining head module 16, and method for adjusting the rotation axis of the machining head 17 disclosed in this embodiment 1, the following effects can be obtained. When the robot control unit 50 controls the movement of the articulated arm 12, the machining head 17 changes its posture so as to displace the pressing portion 43 on the opening edge 41 of the foot 40 against the surface to be drilled S in the circumferential direction, and the rotation axis 34 of the drill 33 rotates in a precessional manner, moving in a conical pattern. During the process in which the pressing portion 43 on the opening edge 41 against the surface to be drilled S is displaced in the circumferential direction, the robot control unit 50 corrects the movement of the articulated arm 12 based on the detection information from the force sensor 45. As the movement of the articulated arm 12 is corrected, the rotational shape of the rotation axis 34 becomes a spiral motion in which the rotational diameter gradually decreases, the reaction force is leveled, and the area of ​​the pressing portion 43 on the opening edge 41 expands in the circumferential direction.

[0042] When the reaction force is leveled over the entire circumference of the opening edge 41, the adjustment of the orientation of the rotation axis 34 is completed, and the rotation axis 34 is oriented perpendicular to the surface to be drilled S. With the multi-axis robot A and machining head module 16 of this embodiment 1, the orientation of the rotation axis 34 is adjusted while the machining head 17 is rotated in a spiral manner, so the time required can be reduced compared to a system that repeatedly performs a seesaw-like motion to make the moment around two axes with different directions zero.

[0043] The robot control unit 50 controls the movement of the articulated arm 12 so that the pressing part 43 is always in contact with the surface to be drilled S. With this configuration, the time required for adjustment can be reduced compared to the case where the pressing part 43 is repeatedly moved away from the surface to be drilled S and then pressed against the surface to be drilled S. The robot control unit 50 controls the movement of the articulated arm 12 so that the pressing part 43 is displaced in only one direction in the circumferential direction of the opening edge 41. With this configuration, the time required for adjustment can be reduced compared to the case where the pressing part 43 is displaced in a reciprocating manner in the circumferential direction of the opening edge 41. Since the force sensor 45 is a 6-axis force sensor, the direction of the rotation axis 34 can be adjusted with higher precision.

[0044] In the axial structure connecting the arms 13 of the robot body 10, there is clearance between the gears that mesh with each other, making it unavoidable that the arms 13 may experience slight relative displacement. Therefore, if the force sensor 45 is placed at a location other than the tip 12A of the articulated arm 12, the reaction force will be transmitted to the force sensor 45 via the axial structure, inevitably resulting in lower detection accuracy of the force sensor 45's detection information. To address this, in this embodiment 1, the force sensor 45 is placed at the tip 12A of the articulated arm 12. With this configuration, the reaction force from the workpiece W is transmitted to the force sensor 45 without going through the axial structure of the arm 13, thus improving the detection accuracy of the force sensor 45.

[0045] <Other examples> The present invention is not limited to the embodiments described above and in the drawings, and the following embodiments, for example, are also included in the technical scope of the present invention. In the adjustment process for the rotation axis of the drill, the action of moving the foot-pressing part away from the surface to be drilled and the action of pressing the foot-pressing part against the surface to be drilled may be repeated. In the adjustment process for the rotation axis of the drill, the part pressed by the foot may be displaced to reciprocate in the circumferential direction of the opening edge. The force sensor may be positioned closer to the proximal end than to the tip of the articulated arm. The force sensor may be a sensor of a form other than a 6-axis force sensor (for example, a 3-axis force sensor). As shown in Figure 7, the detection data from the force sensor may be input to the control device via a separate PC, rather than to the robot control unit. [Explanation of Symbols]

[0046] 10…Multi-axis robot 11…Base 12... Multi-jointed arm 12A... Tip of the multi-jointed arm 13... Arm 14… Joints 15…Servo motor for arm 16… Machining head module 17… Machining head 18...frames 19...Bottom plate part 20…Vertical board section 20R…Rear plate part 21... Top panel 24… Actuator 25... Male threaded rod 26… Guide groove 27…Servo motor for actuator 28…Lifting member 29…Female screw hole 30... Spindle 31…Servo motor for spindle 32... Chuck 33... Drill 34…Rotation axis 35...Communication hole 36... Duct components 37…Cylindrical section 38...Discharge section 40...Foot 41…Opening edge 42…Abutment surface 43…Pressure points 45... Force sensor 46...Control device 48… Servo amplifier for actuators 49... Servo amplifier for spindle 50…Robot Control Unit H...Through hole S... Surface to be perforated W...work

Claims

1. A machining head having a drill that is attached to a multi-joint arm of a multi-axis robot and drills a workpiece while rotating, and a foot that is cylindrical in shape concentric with the drill and has an open edge at the tip that contacts the surface of the workpiece to be drilled, A control device for controlling the processing head, A force sensor that detects the reaction force when the opening edge presses against the surface to be drilled, The robot includes a robot control unit that equalizes the reaction force from the surface to be drilled, The robot control unit controls the movement of the articulated arm based on the detection information from the force sensor, such that the pressing portion on the surface to be drilled at the opening edge is displaced in the circumferential direction and the area of ​​the pressing portion expands in the circumferential direction.

2. The processing head module according to claim 1, wherein the robot control unit controls the movement of the articulated arm so that the pressing portion is always in contact with the surface to be drilled.

3. The processing head module according to claim 1 or 2, wherein the robot control unit controls the movement of the articulated arm so that the pressing portion is displaced in only one direction in the circumferential direction of the opening edge.

4. The machining head module according to claim 1 or claim 2, wherein the force sensor is a 6-axis force sensor.

5. A multi-joint arm in which multiple arms are connected in a way that allows for relative displacement, A machining head having a drill that drills a workpiece while rotating, wherein the direction of the rotation axis of the drill changes by the movement of the articulated arm, The machining head comprises a foot that is cylindrical in shape and concentric with the drill, and whose opening edge at the tip contacts the surface of the workpiece to be drilled, A control device for controlling the processing head, A force sensor that detects the reaction force when the opening edge presses against the surface to be drilled, The robot includes a robot control unit that equalizes the reaction force from the surface to be drilled, The robot control unit controls the movement of the articulated arm of the multi-axis robot based on the detection information of the force sensor, such that the pressing portion on the surface to be drilled at the opening edge is displaced in the circumferential direction and the area of ​​the pressing portion expands in the circumferential direction.

6. The multi-axis robot according to claim 5, wherein the force sensor is positioned between the tip of the articulated arm and the processing head.

7. A multi-joint arm in which multiple arms are connected in a way that allows for relative displacement, A machining head having a drill that drills a workpiece while rotating, wherein the direction of the rotation axis of the drill changes by the movement of the articulated arm, The machining head comprises a foot that is cylindrical in shape and concentric with the drill, and whose opening edge at the tip contacts the surface of the workpiece to be drilled, A control device for controlling the processing head, A force sensor that detects the reaction force when the opening edge presses against the surface to be drilled, A robot control unit is provided to equalize the reaction force from the surface to be drilled, A method for adjusting the rotation axis of a machining head, wherein the robot control unit controls the movement of the articulated arm so that the pressing portion on the surface to be drilled at the opening edge is displaced in the circumferential direction and the area of ​​the pressing portion expands in the circumferential direction, based on the detection information of the force sensor.

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