Method for controlling a friction stir welding device and friction stir welding device

Abstract

With the shoulder member (12) abutting against the contact surface, the pin member (11) is further abutting against the contact surface, and the distance from the initial position of the pin member (11) to the contact surface, i.e., the pin movement amount, and the displacement amount of the shoulder member (12) as it retracts with the abutting of the pin member (11), i.e., the shoulder displacement amount, are determined respectively. If both the first condition that the pin movement amount is included in the first range and the second condition that the shoulder displacement amount is included in the second range are met, the pin member (11) is retracted from the contact surface by a predetermined amount, and the origin of the two members is aligned with the positions of the pin member (11) and the shoulder member (12) in this state as a reference.

Description

Technical Field

[0001] The present invention relates to a control method for aligning the origin of the pin member and the shoulder member in a friction stirring joint device, and the friction stirring joint device thereof. Background Technology

[0002] In the manufacture of structures such as aircraft, railway vehicles, or automobiles, it is sometimes necessary to stack and join two or more components made of metal or resin. Friction stir joining is a known method for this joining. Friction stir joining refers to a method of joining workpieces by pressing a rotating tool into the workpiece (the object to be joined) to induce plastic flow.

[0003] In Patent Document 1 below, as an example of a device for friction stirring and joining, a friction stirring and joining device is disclosed, comprising: a pin member rotatable about an axis and movable forward and backward along the axis; and a shoulder member disposed on the outer periphery of the pin member and rotatable about the axis and movable forward and backward along the axis. The pin member and the shoulder member are respectively driven by rotation and pressed into a workpiece, thereby generating plastic flow in the pressed portion.

[0004] When using the aforementioned friction stirring joint device to join workpieces, it is crucial to manage the relative positions of the pin and shoulder components to ensure a smooth joint. Furthermore, to correctly manage these relative positions, it is necessary to perform a zeroing operation with sufficient precision before the joining process, aligning the origins of the pin and shoulder components. This zeroing operation is sometimes performed manually by the operator. In this case, the operator, for example, in teach mode, moves the pin component while visually or tactilely aligning the distal ends of the pin and shoulder components, setting the origins of the two components in this state. However, this method of zeroing has safety and efficiency issues, and there is room for improvement.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Publication No. 2006-187778 Summary of the Invention

[0008] The present invention was made in view of the aforementioned situation, and its object is to enable safe and efficient alignment of the origin of the pin member and the shoulder member in the friction stirring joint device.

[0009] To address the aforementioned issues, one aspect of the present invention relates to a control method for controlling a friction stirring joining device. The friction stirring joining device includes a pin member that rotates about an axis and moves forward and backward along the axis, and a shoulder member disposed on the outer periphery of the pin member and also rotates about the axis and moves forward and backward along the axis. The workpiece is joined by pressing it into the pin member while rotating the pin member and the shoulder member. The control method for the friction stirring joining device includes: a first step of storing the position of the shoulder member in the axial direction with its distal end abutting a designated abutting surface as a first shoulder position; a second step of storing the initial position of the pin member in the axial direction as a first pin position; a third step of advancing the pin member toward the abutting surface and storing the position of the pin member in the axial direction when its distal end abuts the abutting surface as a second pin position; and a fourth step of storing the shoulder member as it retracts with the pin member abutting the abutting surface. The position of the component in the axial direction is stored as the second shoulder position; Step 5: Determine whether the first condition that the distance between the first pin position and the second pin position, i.e., the pin movement amount, is included in a predetermined first range, and whether the second condition that the distance between the first shoulder position and the second shoulder position, i.e., the shoulder displacement amount, is included in a predetermined second range, is met; Step 6: If the first and second conditions are met, the pin component is retracted from the abutment surface by a predetermined return amount, and the origin alignment of the pin component and the shoulder component is performed based on the respective positions of the retracted pin component and the shoulder component in the axial direction; and Step 7: If at least the first condition is not met, the pin component is retracted to a restart position that is farther away from the abutment surface than the first pin position; wherein, after Step 7, the position of the pin component retracted to the restart position is used as the new first pin position and the steps after Step 2 are executed again.

[0010] Another aspect of the present invention relates to a friction stirring and joining device comprising: a pin member for rotating about an axis and moving forward and backward along the axis; a shoulder member disposed on the outer periphery of the pin member and for rotating about the axis and moving forward and backward along the axis; a zeroing control unit for aligning the origin of the pin member and the shoulder member; a joining control unit for joining the workpiece by rotating the pin member and the shoulder member while pressing them into the workpiece; and a storage unit for storing data; wherein the zeroing control unit is capable of performing: a first process, transferring... The shoulder member's position in the axial direction when its distal end abuts against a designated abutment surface is stored in the storage unit as a first shoulder position; the second process involves storing the pin member's initial position in the axial direction as a first pin position in the storage unit; the third process involves moving the pin member towards the abutment surface and storing the pin member's position in the axial direction when its distal end abuts against the abutment surface as a second pin position in the storage unit; the fourth process involves storing the position of the pin member as it abuts against the abutment surface. The position of the retracted shoulder member in the axial direction is stored as a second shoulder position in the storage unit; the fifth process determines whether the first condition that the distance between the first pin position and the second pin position, i.e., the pin movement amount, is included in a predetermined first range, and whether the second condition that the distance between the first shoulder position and the second shoulder position, i.e., the shoulder displacement amount, is included in a predetermined second range, is met; the sixth process, if the first and second conditions are met, causes the pin member to move from the abutment surface... The pin member is retracted by a predetermined amount, and the origin of the pin member and the shoulder member is aligned with reference to their respective positions in the axial direction after retraction; and, in the seventh process, if at least the first condition is not met, the pin member is retracted to a restart position that is farther away from the abutment surface than the first pin position; wherein, after the seventh process, the zeroing control unit uses the position of the pin member retracted to the restart position as the new first pin position and executes the processes after the second process again. Attached Figure Description

[0011] Figure 1 This is a perspective view including an enlarged view of the key parts of a robot equipped with a friction stirring device according to an embodiment of the present invention.

[0012] Figure 2 This is a schematic side view showing the mechanical configuration of the friction stirring coupling device.

[0013] Figure 3 This is a block diagram showing the electrical structure of the friction stirring coupling device.

[0014] Figure 4 This is a simplified diagram illustrating a pin-first process-based joining method as an example of an operation when joining workpieces using the aforementioned friction stirring joining device.

[0015] Figure 5 This is a simplified diagram illustrating a shoulder-first process-based joining method, which is another example of the operation when joining workpieces using the aforementioned friction stirring joining device.

[0016] Figure 6 This is a flowchart illustrating the first half of the zeroing control performed by the controller to align the origin of the pin and shoulder components in the friction stirring coupling device.

[0017] Figure 7 This is a flowchart representing the latter half of the zeroing control.

[0018] Figure 8A This is a simplified diagram showing the state of the pin and shoulder components in the first stage of the zeroing control.

[0019] Figure 8B This is a simplified diagram showing the state of the pin and shoulder components in the second stage of the zeroing control.

[0020] Figure 8C This is a simplified diagram showing the state of the pin and shoulder components in the third stage of the zeroing control.

[0021] Figure 8D This is a simplified diagram showing the state of the pin and shoulder components in the fourth stage of the zeroing control.

[0022] Figure 9 It means in Figure 6 Step S5 generates a graph of the speed pattern as the pin component descends.

[0023] Figure 10 It is a diagram representing a conditional mapping with pin movement and shoulder displacement as parameters. Detailed Implementation

[0024] The friction stirring and joining apparatus according to an embodiment of the present invention will now be described in detail with reference to the accompanying drawings. The friction stirring apparatus of this embodiment is applicable to the manufacture of various joints formed by the stacking and point-jointing of two or more structural components, wherein the structural components are plates, skeletons, outer materials, or columnar materials formed from metal, thermoplastic resin, or thermoplastic composite materials mixed with fiber-reinforced materials. The manufactured joints are, for example, components of structures such as aircraft, railway vehicles, or automobiles.

[0025] [Examples of applications for friction stirring devices]

[0026] Figure 1 This is a perspective view of a multi-joint robot 5 equipped with the friction stirring and joining device M according to this embodiment. Figure 2 This is a schematic side view showing the configuration of the friction stirring coupling device M. Furthermore, in Figure 1 The winning bid included directions "up" and "down," but this was only for convenience and was not intended to limit the direction of use of the device.

[0027] The multi-joint robot 5 has a robotic arm 51 erected on a base. The robotic arm 51 has multiple arm segments and six joint axes connecting these segments. That is, the robotic arm 51 can rotate around... Figure 1 The first axis AX1, the second axis AX2, the third axis AX3, the fourth axis AX4, the fifth axis AX5, and the sixth axis AX6 shown rotate.

[0028] A gun-shaped component 52 is mounted on the distal end 51T of the robotic arm 51. The gun-shaped component 52 is capable of free three-dimensional movement based on the swing of the robotic arm 51 around the first axis AX1 to the sixth axis AX6. A friction stirring engagement device M is assembled on the gun-shaped component 52.

[0029] Figure 1 An enlarged view of the gun-shaped component 52 is attached. The gun-shaped component 52 includes a frame portion 53 and a C-shaped skeleton 54. The frame portion 53 houses the drive mechanism of the friction stirring engagement device M. The C-shaped skeleton 54 includes a base end portion 541 located on the arm distal end portion 51T side of the frame portion 53 and a distal end portion 542 extending from the base end portion 541 to below the tool 1 described later in the friction stirring engagement device M. The distal end portion 542 holds the back pad member 15 described later.

[0030] Furthermore, the friction stirring coupling device M according to the present invention can also be installed in other devices besides the multi-joint robot 5. For example, an embodiment can be adopted in which the friction stirring device is installed in a mechanical device that moves up and down only along one axis.

[0031] [Mechanical Structure of the Friction Stirring Joint Device]

[0032] Reference Figure 2 The mechanical structure of the friction stirring and joining device M is described below. The friction stirring and joining device M includes: a joining tool 1; a tool driving part 2 that drives the tool 1 to rotate and lift; and a tool fixing part 55 that fixes the tool 1 relative to the workpiece. In this embodiment, the workpiece is an overlapping part 30 formed by the vertical stacking of the first member 31 and the second member 32 that ultimately constitute the connecting body 3.

[0033] Tool 1 includes a pin component 11, a shoulder component 12, a clamping component 13, and a spring 14.

[0034] The pin member 11 is a cylindrical member that extends vertically along its axis Z. Hereinafter, axis Z will be referred to as the tool axis Z. The pin member 11 is rotatable about the tool axis Z and can move forward and backward along the tool axis Z in the vertical direction indicated by arrow Z1. In this embodiment, considering forward and backward movement, downward movement (descending) of the pin member 11 is considered forward movement, and upward movement (rising) of the pin member 11 is considered backward movement. The same applies to the shoulder member 12 and the clamping member 13.

[0035] The shoulder member 12 is configured to cover the outer periphery of the pin member 11. The shoulder member 12 is a cylindrical member with a hollow portion into which the pin member 11 is inserted. The axis of the shoulder member 12 is coaxial with the tool axis Z. Like the pin member 11, the shoulder member 12 can rotate about the tool axis Z and can move forward and backward along the tool axis Z in the up-down direction indicated by arrow Z2. The shoulder member 12 and the pin member 11, which is inserted into the hollow portion, can rotate together about the tool axis Z and can move relative to each other in the direction of the tool axis Z. That is, the pin member 11 and the shoulder member 12 can not only move up and down simultaneously along the tool axis Z, but also can perform independent movements such as one descending while the other rises.

[0036] The clamping member 13 is a cylindrical member with a hollow portion into which the shoulder member 12 is inserted. The axis of the clamping member 13 is also coaxial with the tool axis Z. Although the clamping member 13 does not rotate about its axis, it can move forward and backward along the tool axis Z in the up-down direction indicated by arrow Z3. The clamping member 13 functions to surround the outer periphery of the pin member 11 or the shoulder member 12 during friction-stirring engagement. Due to the surrounding effect of the clamping member 13, the friction-stirring material is prevented from scattering, allowing for a smooth engagement.

[0037] Spring 14 is mounted on the upper end 131 of clamping member 13 in an upward extending manner. Spring 14 applies a force to clamping member 13 in the direction of the overlapping portion 30, that is, downward.

[0038] The tool fixing part 55 includes a rotating tool retainer 551 and a clamping retainer 552. The rotating tool retainer 551 is disposed above the shoulder member 12 into which the pin member 11 is inserted, supporting the pin member 11 and the shoulder member 12. The clamping retainer 552 supports the clamping member 13 by a spring 14. Furthermore, the clamping retainer 552 supports the rotating tool retainer 551 by a rotation drive part 23 described later.

[0039] The backing member 15 is positioned facing the distal end, i.e., the lower end face, of the tool 1. The upper side surface, i.e., the support surface 151, of the backing member 15 is formed as a flat surface for supporting the lower side surface of the workpiece (overlapping portion 30) of the mating object. That is, the backing member 15 is a member that supports the overlapping portion 30 when the pin member 11 or the shoulder member 12 is pressed into the overlapping portion 30. The backing member 15 is held based on the distal end 542 of the C-shaped frame 54. The clamping member 13, which is subjected to force by the spring 14, presses the overlapping portion 30 against the backing member 15. The support surface 151 of the backing member 15 corresponds to the "abutment surface" in this invention.

[0040] As described above, the forward and backward movement axes of the pin member 11 and the shoulder member 12 are both the tool axis Z. Furthermore, the pin member 11 and the shoulder member 12 rotate around the tool axis Z. In this embodiment, since the robotic arm 51 has axes AX1 to AX6, therefore, as... Figure 1 As shown in the enlarged view of the main parts, the forward and backward movement axis of the shoulder member 12 is set as the 7th axis AX7, the rotation axis of the pin member 11 and the shoulder member 12 is set as the 8th axis AX8, and the forward and backward movement axis of the pin member 11 is set as the 9th axis AX9.

[0041] The tool drive unit 2 includes a pin drive unit 21, a shoulder drive unit 22, and a rotation drive unit 23.

[0042] The pin drive unit 21 is a mechanism that moves the pin member 11 forward and backward (lifts and lowers) along the tool axis Z; in other words, it is a drive mechanism for the 9th axis AX9. The pin member 11 is driven by the pin drive unit 21 in a manner that the lower end, i.e., the distal end 11T, moves downward (forward) toward the overlapping portion 30 or rises relative to the overlapping portion 30 (reverses). The pin drive unit 21 includes: a servo motor 21a as the drive source. Figure 3 The gear mechanism, consisting of a rack / pinion, etc., converts the rotation of the output shaft of the servo motor 21a into linear motion (up and down motion) along the tool axis Z.

[0043] The shoulder drive unit 22 is a mechanism that moves the shoulder member 12 forward and backward (lifts and lowers) along the tool axis Z; in other words, it is a drive mechanism for the 7th axis AX7. The shoulder member 12 is driven by the shoulder drive unit 22 in a manner that the lower end, i.e., the distal end 12T, moves downward (forward) toward the overlapping portion 30 or upward (backward) relative to the overlapping portion 30. The shoulder drive unit 22 includes: a servo motor 22a as the drive source. Figure 3 The gear mechanism, consisting of a rack / pinion, etc., converts the rotation of the output shaft of the servo motor 22a into linear motion (up and down motion) along the tool axis Z.

[0044] In this embodiment, the shoulder drive unit 22 is a mechanism that raises and lowers the tool fixing part 55 of the support pin member 11, the shoulder member 12, and the clamping member 13. Therefore, as Figure 2 As shown, the movement of the pin member 11, shoulder member 12 and clamping member 13 in the directions of arrows Z1, Z2 and Z3 is all achieved by the drive of the shoulder drive unit 22.

[0045] However, the pin member 11 can move forward and backward independently of the shoulder member 12 and the clamping member 13, driven by the pin drive unit 21. That is, the pin drive unit 21 is a mechanism that is fixed to the inside of the shoulder member 12 and raises and lowers the pin member 11 relative to this fixed position. Thus, even when, for example, the shoulder member 12 is lowered or stopped, the pin member 11 can still rise based on the drive of the pin drive unit 21.

[0046] With the clamping member 13 lowered based on the shoulder drive portion 22 and its distal end (lower end) 13T abutting against the overlapping portion 30, the force of the spring 14 acts on the clamping member 13. Based on this force, the clamping member 13 presses the overlapping portion 30 against the back pad member 15, thereby fixing the positional relationship between the overlapping portion 30 and the tool 1.

[0047] The rotation drive unit 23 is a mechanism that rotates the pin member 11 and the shoulder member 12 about the tool axis Z; in other words, it is a drive mechanism for the 8th axis AX8. The rotation drive unit 23 includes a servo motor 23a as the drive source. Figure 3 The servo motor 23a's output shaft rotation is transmitted via a gear mechanism. The rotation drive 23 is held by the clamping retainer 552 and the rotation drive rotates the tool retainer 551. Based on this rotation drive, the pin member 11 and shoulder member 12, supported by the tool retainer 551, rotate about the tool axis Z.

[0048] [Electrical structure of the friction stirring coupling device]

[0049] Figure 3 This is a block diagram showing the electrical structure of the friction stirring coupling device M. The friction stirring coupling device M includes a controller 61, an input unit 62, and a storage unit 63 as its functional elements.

[0050] The controller 61 includes a microcomputer and other components, and controls the movement of the tool drive unit 2 and the robot drive unit 51M by executing a specified control program. The robot drive unit 51M includes actuators that drive the first axis AX1 to the sixth axis AX6 of the robotic arm 51.

[0051] The controller 61 controls the tool drive unit 2 as follows: The controller 61 controls the servo motor 21a of the pin drive unit 21, causing the pin member 11 to move independently forward and backward. Furthermore, the controller 61 controls the servo motor 22a of the shoulder drive unit 22, causing the pin member 11, shoulder member 12, and clamping member 13 to perform the required forward and backward movements respectively. Moreover, the controller 61 controls the servo motor 23a of the rotation drive unit 23, causing the pin member 11 and shoulder member 12 to rotate about the tool axis Z.

[0052] The controller 61 also includes a zeroing control unit 61a and an engagement control unit 61b. The engagement control unit 61b is a control module for frictionally stirring and engaging the workpiece (overlapping portion 30) using the pin member 11 and shoulder member 12. Specifically, the engagement control unit 61b engages the workpiece by rotating the pin member 11 and shoulder member 12 while pressing them into the workpiece (overlapping portion 30). The zeroing control unit 61a is a control module for automatically aligning (zeroing) the origin of the pin member 11 and shoulder member 12. Details regarding this origin alignment will be described later.

[0053] The input unit 62 is an interface for inputting various data and instructions to the controller 61, such as having a keyboard or a touch screen.

[0054] Storage unit 63 stores various programs and data required for controlling the friction stirring and joining device M.

[0055] [Example of friction-stirring joint action]

[0056] Friction stirring joints performed using the friction stirring joint device M with the above-described configuration are broadly classified into joints based on a pin-first process and joints based on a shoulder-first process. The difference between the pin-first process and the shoulder-first process lies in whether the pin member 11 is pressed in first or the shoulder member 12 is pressed in first. A summary of each process is as follows.

[0057] Figure 4 This is a simplified diagram illustrating a pin-first bonding method. The pin-first bonding method comprises the following four steps, P11 to P14.

[0058] Step P11 is the preheating step for the overlapping portion 30. In the preheating step, with the distal end (lower end) of the tool 1 abutting the surface of the first member 31, the pin member 11 and the shoulder member 12 are rotated at high speed around the axis at a specified rotation speed. Based on the frictional heat generated by this high-speed rotation, the material of the portions abutting the distal ends 11T and 12T of the pin member 11 and the shoulder member 12 softens, and a plastic flow portion is generated near the upper side surface of the overlapping portion 30.

[0059] Step P12 is the pressing-in step of the pin member 11. In the pressing-in step, as shown by the hollow arrow in the figure, the pin member 11 is lowered and pressed into the overlapping portion 30, while the shoulder member 12 is raised. Based on this action, softened material overflows from the pressing area of ​​the pin member 11. The overflowed material OF is released, as shown by arrow a1, into an annular area between the pin member 11 and the clamping member 13, created by the raising (retraction) of the shoulder member 12.

[0060] Step P13 is the backfilling step for the overflowed material OF. In the backfilling step, the pin member 11 is raised on one hand, and the shoulder member 12 is lowered on the other. Based on the descent of the shoulder member 12, the overflowed material OF released into the annular region is backfilled into the pressing area of ​​the pin member 11 as shown by arrow a2.

[0061] Step P14 is a leveling step. In the leveling step, the pin member 11 and the clamping member 13 are rotated so that the distal ends 11T and 12T are returned to the height position of the surface of the first member 31. As a result, the upper side surface of the overlapping portion 30 is shaped and smoothed to the point that there is almost no unevenness.

[0062] Based on the above steps P11 to P14, a smooth upper side joint 4a is formed, and the first member 31 and the second member 32 are joined at the overlapping part 30.

[0063] Figure 5 This is a simplified diagram illustrating a shoulder-first process-based joining method. The shoulder-first process-based joining method comprises the following four steps, P21 to P24.

[0064] Step P21 is the same preheating step for the overlapping portion 30 as step P11 described above. In this preheating step, the material of the portions that abut against the distal ends 11T and 12T of the high-speed rotating pin member 11 and shoulder member 12 softens, and a plastic flow portion is generated near the upper side of the overlapping portion 30.

[0065] Step P22 is the pressing-in step of the shoulder member 12. In this pressing-in step, the shoulder member 12 is lowered and pressed into the overlapping portion 30, while the pin member 11 is raised. Based on this action, softened material overflows from the pressing area of ​​the shoulder member 12. The overflowed material OF is released into the hollow space of the shoulder member 12 created by the raising (retraction) of the pin member 11, as shown by arrow b1.

[0066] Step P23 is the backfilling step for the overflowing material OF. In the backfilling step, the shoulder member 12 is raised on one hand, and the pin member 11 is lowered on the other. Based on the lowering of the pin member 11, the overflowing material OF released into the hollow space is backfilled into the pressing area of ​​the shoulder member 12 as shown by arrow b2.

[0067] Step P24 is the same smoothing step as step P14 described above. Based on this smoothing step, the upper side surface of the overlapping portion 30 is shaped and smoothed to the point that there is almost no unevenness.

[0068] Based on the above process, a smooth upper side joint 4b is formed, and the first component 31 and the second component 32 are joined at the overlapping part 30.

[0069] [Example of resetting to zero]

[0070] As described above, even when using either the pin-first or shoulder-first joining method, a smooth joint (4a or 4b) can be formed in the overlapping portion 30. To ensure the smoothness of the joint, especially during the leveling step, it is necessary to align the distal end 11T of the pin member 11 and the distal end 12T of the shoulder member 12 with sufficient precision to ensure they are at the same height. To ensure such alignment precision, it is required that before joining, the heights of the distal ends 11T and 12T of the pin member 11 and shoulder member 12 be aligned with sufficient precision, and the origins of the two members 11 and 12 be zeroed out in this state. Here, the origin of the pin member 11 and the shoulder member 12 refers to the origin of the Z-axis coordinate when the coordinate along the forward and backward movement axis of the two members 11 and 12, i.e., the tool axis Z, is used as the Z-axis coordinate. That is, the origin alignment (zeroing) mentioned here refers to the operation of aligning the origin of the Z-axis coordinate of the pin component 11 with the origin of the Z-axis coordinate of the shoulder component 12.

[0071] Figure 6 and Figure 7 This is a flowchart illustrating the specific steps of the zeroing control performed by controller 61 during zeroing. Zeroing control is performed after the friction stirring assembly M is assembled and before it is shipped to the user. Furthermore, zeroing control is executed according to a program pre-stored in storage unit 63, which is initiated by the operator inputting a zeroing command into controller 61 via input unit 62 based on the instruction to start the program, i.e., the zeroing command.

[0072] Start upon receiving the zeroing command input. Figure 6 After the control shown, the zeroing control unit 61a of the controller 61 causes the shoulder member 12 to descend toward the back pad member 15 (step S1). That is, the zeroing control unit 61a rotates the servo motor 22a of the shoulder drive unit 22 in the direction of the shoulder member 12 descending, so that the shoulder member 12 descends (advances) until the distal end 12T of the shoulder member 12 abuts against the support surface 151 of the back pad member 15.

[0073] However, in step S1, at the moment the shoulder member 12 begins to descend, the origin of the Z-axis coordinate of the shoulder member 12 is not clear; only a temporary origin exists. That is, the position of the shoulder member 12 on the Z-axis coordinate is identified based on the output of the encoder (position detection unit) provided with the servo motor 22a, but the origin of the Z-axis coordinate at this time is a temporary origin set by default during the assembly of the friction stirring coupling device M. Therefore, for the zeroing control unit 61a, the distance from the distal end 12T of the shoulder member 12 at the initial position to the support surface 151 of the back pad member 15 is not clear. For this reason, the zeroing control unit 61a sets a virtual target value for the Z-axis coordinate, such that the distal end 12T of the shoulder member 12 must abut against the support surface 151 of the back pad member 15, based on the value of the Z-axis coordinate before the servo motor 22a is driven, i.e., the initial value of the Z-axis coordinate, and controls the servo motor 22a to descend to this virtual target value. Here, the positive direction of the Z-axis coordinate is the upward direction. In this case, the virtual target value of the Z-axis coordinate can be set, for example, by subtracting a value greater than or equal to the maximum forward / backward movement of the shoulder member 12 from the initial value of the Z-axis coordinate. The maximum forward / backward movement of the shoulder member 12 refers to the amount of movement in the Z-axis direction when the shoulder member 12 moves from the upper limit of its movable area to the support surface 151 of the back pad member 15. The upper limit of the movable area of ​​the shoulder member 12 can be set, for example, to the position where the shoulder member 12 abuts against the upper mechanical stop.

[0074] Next, the zeroing control unit 61a determines whether the distal end 12T of the shoulder member 12 abuts against the support surface 151 of the back pad member 15 (step S2). For example, the zeroing control unit 61a determines the abutment of the shoulder member 12 based on the operating current of the servo motor 22a. That is, if the shoulder member 12 abuts against the back pad member 15, the load on the servo motor 22a increases, resulting in an increase in the operating current of the servo motor 22a. Therefore, when the zeroing control unit 61a confirms that the operating current has increased to a specified value, it determines that the shoulder member 12 abuts against the back pad member 15. Here, in the friction stirring and joining device M of this embodiment, the shoulder member 12 functions as a pressure shaft, and the control logic for determining the pressure based on the operating current of the servo motor 22a is implemented by the controller 61. The determination in step S2 can be performed without hindrance using such control logic.

[0075] When the determination in step S2 is "yes" and it is confirmed that the shoulder member 12 abuts against the back pad member 15, the zeroing control unit 61a stores the value of the Z-axis coordinate of the shoulder member 12 at this time as the first shoulder axis value α1 in the storage unit 63 (step S3). Figure 8AThis indicates that the distal end 12T of the shoulder member 12 is in contact with the support surface 151 of the back pad member 15. The zeroing control unit 61a stores the Z-axis coordinate value of the shoulder member 12 in this contact state as the first shoulder axis value α1 in the storage unit 63. The first shoulder axis value α1 corresponds to the "first shoulder position" in this invention.

[0076] Next, the zeroing control unit 61a, as follows Figure 8B As shown, the current value of the Z-axis coordinate of the pin member 11 is stored in the storage unit 63 as the first pin value β1 (step S4). At the moment of step S4, the pin member 11 neither rises nor falls, so the first pin value β1 can be referred to as the initial value of the Z-axis coordinate of the pin member 11. The first pin value β1 corresponds to the "first pin position" in this invention.

[0077] Next, the zeroing control unit 61a lowers the pin member 11 toward the back pad member 15 (step S5). That is, the zeroing control unit 61a rotates the servo motor 21a of the drive pin drive unit 21 in the direction of the pin member 11's descent, causing the pin member 11 to descend (advance) until the distal end 11T of the pin member 11 abuts against the support surface 151 of the back pad member 15.

[0078] However, in step S5, at the moment the pin member 11 begins to descend, the origin of the Z-axis coordinate of the pin member 11 is not clear; only a temporary origin exists. That is, the position of the pin member 11 on the Z-axis coordinate is identified based on the output of the encoder (position detection unit) provided with the servo motor 21a, but the origin of the Z-axis coordinate at this time is a temporary origin set by default during the assembly of the friction stirring coupling device M. Therefore, similar to when the shoulder member 12 is descended in step S1, the zeroing control unit 61a sets a virtual target value for the Z-axis coordinate, such that the distal end 11T of the pin member 11 must abut against the support surface 151 of the back pad member 15, based on the value of the Z-axis coordinate before the servo motor 21a is about to be driven, i.e., the initial value of the Z-axis coordinate, and controls the servo motor 21a to descend to this virtual target value. In this case, the virtual target value of the Z-axis coordinate can be, for example, a value obtained by subtracting a value greater than or equal to the maximum forward and backward movement of the pin member 11 from the initial value of the Z-axis coordinate.

[0079] like Figure 9As shown, in step S5, the zeroing control unit 61a controls the servo motor 21a to change the descent speed of the pin member 11, i.e., the pin descent speed, according to a specified speed pattern. That is, the zeroing control unit 61a accelerates the pin member 11 simultaneously with the start of step S5, increasing the pin descent speed towards a predetermined target speed V1. Furthermore, after the pin descent speed reaches the target speed V1, the zeroing control unit 61a maintains a constant pin descent speed at the target speed V1 after time t1. The target speed V1 is set to a value sufficiently low (e.g., a few mm / s) relative to the upper limit of the pin descent speed.

[0080] Next, the zeroing control unit 61a determines whether the distal end 11T of the pin member 11 abuts against the support surface 151 of the back pad member 15 (step S6). For example, the zeroing control unit 61a investigates the time variation of the deviation between the virtual target value set in step S5 and the current Z-axis coordinate of the pin member 11 based on the output value of the encoder from the servo motor 21a. If it is confirmed that the deviation has not substantially changed during the specified period, it determines that the pin member 11 abuts against the back pad member 15. Thus, the abutment determination of the pin member 11 is different from the abutment determination of the shoulder member 12 described above (step S2). It is not based on the motor current, but on the coordinate position deviation. This is because the control logic of the pin member 11 and the shoulder member 12 is different. That is, in the friction stirring coupling device M of this embodiment, the pin member 11 functions as a direct-acting shaft, which is different from the case of the shoulder member 12, which functions as a pressure shaft. The control logic for determining the pressure based on the motor current is not applicable to the pin member 11. Therefore, in step S6, the engagement of the pin member 11 is determined based on the coordinate position deviation rather than the motor current.

[0081] When the determination in step S6 is "yes" and it is confirmed that the pin member 11 abuts against the back pad member 15, the zeroing control unit 61a stores the value of the Z-axis coordinate of the pin member 11 at this time as the second pin value β2 in the storage unit 63 (step S7). Figure 8C This indicates that the distal end 11T of the pin member 11 is in contact with the support surface 151 of the back pad member 15. The zeroing control unit 61a stores the Z-axis coordinate value of the pin member 11 in this contact state as the second pin value β2 in the storage unit 63. The second pin value β2 corresponds to the "second pin position" in this invention.

[0082] Next, the zeroing control unit 61a, as follows Figure 8CAs shown, the current value of the Z-axis coordinate of the shoulder member 12 is stored in the storage unit 63 as the second shoulder axis value α2 (step S8). That is, when the pin member 11 abuts against the back pad member 15 as described above, it can be observed that the shoulder member 12 is slightly displaced (raised) upwards due to this effect. Therefore, in step S8, the current value of the Z-axis coordinate of the shoulder member 12 is investigated to confirm the position of the shoulder member 12 after this upward displacement. The second shoulder axis value α2 corresponds to the "second shoulder position" in this invention.

[0083] Here, the upward displacement of the shoulder member 12 described above can be considered as a phenomenon caused by the structure of the friction stirring engagement device M of this embodiment, where the pin member 11 rises and falls relative to the shoulder member 12 based on the pin drive portion 21 fixed to the inner side of the shoulder member 12. For example, when the pin member 11 abuts against the back pad member 15 and presses the back pad member 15, its reaction force acts on the shoulder member 12 via a gear mechanism such as a rack / pinion in the pin drive portion 21, resulting in a slight upward displacement of the shoulder member 12. At this time, the displacement of the shoulder member 12 is small. Figure 8C The extent of this has been exaggerated.

[0084] Next, the zeroing control unit 61a calculates the pin movement amount (β1-β2) based on the first pin value β1 obtained in step S4 and the second pin value β2 obtained in step S7. Figure 7 Step S9). That is, the zeroing control unit 61a calculates the distance from the initial position of the pin member 11 to the back pad member 15, i.e., the pin movement amount (β1-β2), by subtracting the second pin value β2, which indicates the position when the pin member 11 abuts against the back pad member 15, from the first pin value β1, which indicates the initial position of the pin member 11.

[0085] Next, the zeroing control unit 61a calculates the shoulder displacement (α2-α1) based on the first shoulder axis value α1 obtained in step S3 and the second shoulder axis value α2 obtained in step S8 (step S10). That is, the zeroing control unit 61a calculates the shoulder displacement (α2-α1) of the shoulder member 12 from the back pad member 15 by subtracting the first shoulder axis value α1, which represents the position of the shoulder member 12 when it is in contact with the back pad member 15, from the second shoulder axis value α2, which represents the position of the shoulder member 12 after upward displacement (backward displacement) based on the contact between the pin member 11 and the back pad member 15.

[0086] Next, the zeroing control unit 61a determines whether the first condition is met: the pin movement amount (β1-β2) calculated in step S9 is greater than or equal to a predetermined reference movement amount Xβ (step S11). The reference movement amount Xβ used here is set to be such that when the pin member 11 moves along... Figure 9 The indicated speed pattern decreases, causing the pin member 11 to travel a distance or more necessary to reach the target speed V1. In other words, if the pin movement (β1-β2) is greater than or equal to the reference movement Xβ, then the pin member 11 will move at the target speed V1 at the moment of contact with the back pad member 15. Conversely, if the pin movement (β1-β2) is less than the reference movement Xβ, then the pin member 11's descent speed at the moment of contact with the back pad member 15 may not have reached the target speed V1, meaning the pin member 11 may still be accelerating.

[0087] If the condition is confirmed as "yes" in step S11, i.e., β1-β2≥Xβ, the zeroing control unit 61a determines whether the second condition is met (step S12) that the shoulder displacement (α2-α1) calculated in step S10 is less than or equal to a predetermined reference displacement Xα. The reference displacement Xα used here corresponds to the displacement of the pin member 11 at... Figure 9 The maximum value of the upward displacement of the shoulder member 12 that may occur when the target velocity V1 comes into contact with the back pad member 15 can be determined experimentally.

[0088] Based on the results of each determination in steps S11 and S12, in other words, depending on whether the first and second conditions are met, the zeroing control unit 61a performs three different controls. First, the control when the determination in step S12 is "yes", that is, when the second condition is confirmed to be met, will be explained.

[0089] In step S12, confirming that the second condition is true means that both the first and second conditions are true, which means that β1-β2≥Xβ and α2-α1≤Xα. That is, as... Figure 10 As shown, this means that on the condition mapping diagram with the pin movement (β1-β2) as the horizontal axis and the shoulder displacement (α2-α1) as the vertical axis, the condition of the first region R1 in the lower right is met. In this case, the zeroing control unit 61a raises the pin member 11 by a predetermined return amount Bx (step S13). The predetermined return amount Bx is a predetermined constant value, which is an experimentally obtained value to make the height of the distal end 11T of the pin member 11 match the height of the distal end 12T of the shoulder member 12. By raising the pin member 11 by such a predetermined return amount Bx, as Figure 8D As shown, the distal end 11T of the pin member 11 and the distal end 12T of the shoulder member 12 are aligned flush.

[0090] Here, the fixed return value Bx does not necessarily correspond to the amount of rise from the shoulder member 12 of the backrest member 15, i.e., the shoulder displacement (α2-α1), but Figure 8CThe height deviation (positional deviation) of the distal ends 11T and 12T of the pin member 11 and shoulder member 12 in the desired state is more consistent with the shoulder displacement (α2-α1) and the predetermined return amount Bx. That is, according to the inventor's understanding, the shoulder displacement (α2-α1) determined based on the encoder does not correctly match the actual height deviation of the distal ends 11T and 12T of the pin member 11 and shoulder member 12. This could be due to errors caused by distortion of the components, etc. Therefore, even if the pin member 11 is moved from... Figure 8C The rise in the state is the same as the shoulder displacement (α2-α1), and the heights of the distal ends 11T and 12T of the pin member 11 and the shoulder member 12 may not be consistent. Instead, it was found that the height deviations of the distal ends 11T and 12T are substantially the same when both the first and second conditions are met. Based on this finding, the experimentally obtained constant predetermined return amount Bx is predetermined in the procedure for zeroing control. In step S13, by raising the pin member 11 by the predetermined return amount Bx thus determined, as... Figure 8D As shown, the distal ends 11T and 12T of the pin member 11 and the shoulder member 12 are aligned uniformly.

[0091] Next, the zeroing control unit 61a performs origin alignment of the Z-axis coordinates of the pin member 11 and the shoulder member 12, which is called zeroing (step S14). That is, after executing step S13, which raises the pin member 11 by a predetermined return amount Bx, the zeroing control unit 61a uses the current positions of the pin member 11 and the shoulder member 12 as a reference to perform origin alignment of the two members 11 and 12. More specifically, after step S13 is executed, the zeroing control unit 61a performs the zeroing control unit aligning the origins of the two members 11 and 12. Figure 8D In the current state, the origins of the pin member 11 and the shoulder member 12 are reset so that the Z-axis coordinate value of the pin member 11 determined based on the encoder output value of the servo motor 21a is consistent with the Z-axis coordinate value of the shoulder member 12 determined based on the encoder output value of the servo motor 22a.

[0092] For example, the zeroing control unit 61a corrects the relationship between the encoder output value of servo motor 21a and the Z-axis coordinate value, and the relationship between the encoder output value of servo motor 22a and the Z-axis coordinate value, respectively, and resets the origins of pin member 11 and shoulder member 12, thereby achieving the above-mentioned Figure 8D In the reset state, the Z-axis coordinate value of the pin component 11 is consistent with the Z-axis coordinate value of the shoulder component 12. After resetting, the origins of the pin component 11 and the shoulder component 12 only need to be within... Figure 8D When the Z-axis coordinate values ​​are consistent in a certain state, the device can be set to an appropriate position. For example, the pin member 11 and the shoulder member 12 can be positioned... Figure 8DThe origin is reset in such a way that the Z-axis coordinates of both components 11 and 12 are both 0, representing the origin. Alternatively, the origin can be reset in the same state. Figure 8D In the state where the Z-axis coordinates of both components 11 and 12 are small positive values ​​corresponding to the predetermined return amount Bx, the origin is reset. In the latter case, it is expected that the Z-axis coordinates of the pin component 11 and the shoulder component 12 are 0 when they are in contact with the back pad component 15.

[0093] Secondly, the control is explained when the condition is determined to be "no" in step S11, confirming that the first condition is not met. Confirming the first condition is not met in step S11 means that both the first and second conditions are not met, or the first condition is not met while the second condition is met. The former means β1-β2 < Xβ and α2-α1 > Xα, and the latter means β1-β2 < Xβ and α2-α1 ≤ Xα. That is, being determined to be "no" in step S11 means that in a situation where the pin movement (β1-β2) is the horizontal axis and the shoulder displacement (α2-α1) is the vertical axis... Figure 10 On the condition mapping diagram, the conditions of the second region R2 in the lower left or the third region R3 in the upper left are met. In this case, the zeroing control unit 61a causes the pin member 11 to rise by a distance greater than or equal to the reference movement Xβ (step S15).

[0094] Before performing step S15, the pin component 11 is as follows: Figure 8C As shown, the pin member 11 is in contact with the backing member 15. Therefore, based on the execution of step S15, the pin member 11 rises a distance greater than the reference movement amount Xβ from the backing member 15. Hereinafter, the position of the pin member 11 when it has completed its rise will be referred to as the restart position. The restart position can be set at a position that is the same distance away from the backing member 15 (support surface 151) as the reference movement amount Xβ, but it can also be set at a position that is a certain distance away from the reference movement amount Xβ, depending on the allowance. Alternatively, the upper limit of the movable area of ​​the pin member 11, that is, the position where the pin member 11 contacts the mechanical stop, can be set as the restart position.

[0095] After step S15, the process returns to step S4. In this case, in step S4, the zeroing control unit 61a stores the Z-axis coordinate value of the pin member 11 after it has risen to the restart position based on the control in step S15 in the storage unit 63 as a new first pin value β1. That is, the zeroing control unit 61a rewrites the first pin value β1 stored in the storage unit 63 from the value stored in the previous step S4 to the Z-axis coordinate value when the pin member 11 rises to the restart position.

[0096] Subsequently, the control following step S5 is repeated in the same manner. That is, the zeroing control unit 61a lowers the pin member 11, which has risen to the restart position, until it abuts against the back pad member 15 (steps S5, S6), and stores the Z-axis coordinate values ​​of the pin member 11 and the shoulder member 12 at this moment as the new second pin axis value β2 and the second shoulder axis value α2 (steps S7, S8). Furthermore, it determines whether the first and second conditions are met based on the pin movement amount (β1-β2) and shoulder displacement amount (α2-α1) calculated using each axis value (steps S9 to S12), and performs appropriate control based on the determination result (steps S13 to S16).

[0097] Secondly, the control is explained when the condition is determined to be "no" in step S12, confirming that the second condition is not met. Confirming the second condition is not met in step S12 means that the first condition is met while the second condition is not met, i.e., β1-β2≥Xβ and α2-α1>Xα. That is, it means that when the pin movement (β1-β2) is used as the horizontal axis and the shoulder displacement (α2-α1) is used as the vertical axis... Figure 10 On the condition mapping diagram, the condition of region R4 in the upper right corner is met. In this case, the zeroing control unit 61a displays the specified error message (step S16). For example, the zeroing control unit 61a causes an off-screen display device, such as a liquid crystal panel, to display a specified error message indicating that there may be an abnormality in the friction stirring joint device M.

[0098] That is, according to the inventor's understanding, if the first condition regarding the pin movement (β1-β2) is met, then the second condition regarding the shoulder displacement (α2-α1) is also likely to be met. Conversely, the situation where the first condition is met but the second condition is not is generally unforeseen, and the friction stirring engagement device M may malfunction. Therefore, in step S16, an error message is displayed to notify the operator of this situation.

[0099] In the zeroing control described above, Figure 6 Step S3 corresponds to "Step 1" or "Process 1" in this invention. Figure 6 Step S4 corresponds to "step 2" or "second process" in this invention. Figure 6 Steps S5 to S7 correspond to "step 3" or "process 3" in this invention. Figure 6 Step S8 corresponds to "step 4" or "process 4" in this invention. Figure 7 Steps S11 and S12 correspond to "step 5" or "process 5" in this invention. Figure 7 Steps S13 and S14 correspond to "step 6" or "process 6" in this invention. Figure 7Step S15 corresponds to the "7th step" or "7th process" of the present invention.

[0100] [Effects, etc.]

[0101] As described above, in this embodiment, the alignment of the origin of the pin member 11 and the shoulder member 12 in the friction stirring coupling device M is performed by the following steps.

[0102] With the shoulder member 12 abutting against the back pad member 15, the pin member 11 is further abutted against the back pad member 15, and the distance from the initial position of the pin member 11 to the back pad member 15, i.e., the pin movement amount (β1-β2), and the displacement amount when the shoulder member 12 slightly rises and moves as the pin member 11 abuts, i.e., the shoulder displacement amount (α2-α1), are investigated.

[0103] • Determine whether the first condition, that the pin movement (β1-β2) is greater than or equal to the reference movement Xβ, and whether the second condition, that the shoulder displacement (α2-α1) is less than or equal to the reference displacement Xα, is met.

[0104] • When both conditions 1 and 2 are met, the pin member 11 is raised from the back pad member 15 by a predetermined return amount Bx. Using the positions of the pin member 11 and the shoulder member 12 in this state as a reference, the origins of the two members 11 and 12 are aligned.

[0105] If condition 1 is not met, the same steps are repeated from the starting position after the rise, with the pin component 11 rising by a distance greater than the reference movement Xβ.

[0106] In this embodiment of origin alignment using such a method, there is an advantage that it can both ensure the accuracy of origin alignment and improve the efficiency and safety of origin alignment.

[0107] As described above, it is known that when the shoulder member 12 abuts against the back pad member 15, and the pin member 11 further abuts against the back pad member 15, the shoulder member 12 rises slightly (retracts) as the pin member 11 abuts against it. Furthermore, it is known that the height deviation of the distal ends 11T and 12T of the pin member 11 and the shoulder member 12 caused by this upward displacement (see reference) Figure 8CThis is uniquely determined when both the first and second conditions are met. In this embodiment, when it is confirmed that both the first and second conditions are met, the pin member is driven upward by a constant predetermined return amount Bx. Therefore, the height of the distal end 11T of the raised pin member 11 can be accurately matched with the height of the distal end 12T of the shoulder member 12. Moreover, by aligning the origin of the pin member 11 and the shoulder member 12 in this state, the accuracy of the origin alignment can be improved, and the joining performance of the friction stirring joint device M equipped with these pin members 11 and shoulder members 12 can be improved. For example, when joining the overlap 30 of the first member 31 and the second member 32, the performance of smoothly completing the upper side of the joint can be improved.

[0108] Furthermore, by performing the action of sequentially abutting the shoulder member 12 and the pin member 11 against the same back pad member 15, and determining the positions of the shoulder member 12 and the pin member 11 at each stage as the first and second shoulder axis values ​​α1, α2 and the first and second pin axis values ​​β1, β2, it is possible to determine whether the first and second conditions are met based on these positions. Moreover, if both conditions are met, simply raising the pin member 11 by a predetermined return amount Bx is sufficient to make the heights of the pin member 11 and the shoulder member 12 consistent. Therefore, a series of steps can be automated, and origin alignment can be easily performed, improving the efficiency and safety of origin alignment.

[0109] On the other hand, if at least the first condition is not met, the pin member 11 rises to a starting position away from the back pad member 15 and repeats the same steps from that position. Therefore, it is possible to achieve a situation where the heights of the pin member 11 and the shoulder member 12 are consistent as much as possible, and the probability of automatically achieving origin alignment can be increased.

[0110] Furthermore, in the described embodiment, the reference movement amount Xβ, which serves as the threshold for determining the first condition, is set to be greater than or equal to the distance required to ensure that the pin member 11 abuts against the back pad member 15 at a constant target speed V1, i.e., the distance necessary to accelerate the pin member 11 to the target speed V1. Therefore, the height deviation when the first and second conditions are met is... Figure 8C The height difference between the 11T and 12T ends in the state is more stable, which can significantly improve the accuracy of the origin alignment.

[0111] Furthermore, in the described embodiment, when the pin movement (β1-β2) is greater than or equal to the reference movement Xβ, the first condition is deemed to be met; when the shoulder displacement (α2-α1) is less than or equal to the reference displacement Xα, the second condition is deemed to be met. However, the first condition only requires that the pin movement is within a specified first range, and the second condition only requires that the shoulder displacement is within a specified second range. For example, the first range can be a range that has both a lower limit and an upper limit, and the second range can be a range that has both a lower limit and an upper limit greater than zero.

[0112] In the described embodiment, the deviation of the Z-axis coordinate value of the pin member 11 when it abuts against the back pad member 15 is investigated, that is, the deviation between the target value and the current value of the Z-axis coordinate. If the deviation does not change substantially within a specified period, it is determined that the pin member 11 abuts against the back pad member 15. However, the method for determining the abutment of the pin member 11 is not limited to this. For example, similar to the case of determining the abutment of the shoulder member 12, the abutment of the pin member 11 can also be determined based on the operating current of the servo motor 21a that drives the pin member 11.

[0113] [Summarize]

[0114] The above-described embodiments and their variations mainly include the following inventions.

[0115] One aspect of the present invention relates to a method for controlling a friction stir joining device, the friction stir joining device comprising a pin member that rotates about an axis and moves forward and backward along the axis, and a shoulder member disposed on the outer periphery of the pin member and rotating about the axis and moving forward and backward along the axis, wherein the workpiece is joined by pressing the pin member and the shoulder member into the workpiece while rotating. The control method of the friction stir joining device includes: a first step of storing the position of the shoulder member in the axial direction with the distal end of the shoulder member abutting against a designated abutting surface as a first shoulder position; a second step of storing the initial position of the pin member in the axial direction as a first pin position; a third step of advancing the pin member toward the abutting surface and storing the position of the pin member in the axial direction with the distal end of the pin member abutting against the abutting surface as a second pin position; and a fourth step of storing the position of the shoulder member as it retracts with the pin member abutting against the abutting surface. The position in the axial direction is stored as the second shoulder position; Step 5: Determine whether the first condition that the distance between the first pin position and the second pin position, i.e., the pin movement amount, is included in a predetermined first range, and whether the second condition that the distance between the first shoulder position and the second shoulder position, i.e., the shoulder displacement amount, is included in a predetermined second range, is met; Step 6: If the first and second conditions are met, the pin member is retracted from the abutment surface by a predetermined return amount, and the origin alignment of the pin member and the shoulder member is performed based on their respective positions in the axial direction after retraction; and Step 7: If at least the first condition is not met, the pin member is retracted to a restart position that is farther away from the abutment surface than the first pin position; wherein, after Step 7, the position of the pin member retracted to the restart position is used as the new first pin position, and the steps after Step 2 are executed again.

[0116] According to this control method, the movement distance of the pin component from its initial position to the contact surface (i.e., pin movement amount) and the displacement amount of the shoulder component as it retracts after contacting the contact surface (i.e., shoulder displacement amount) are investigated. The origin alignment of the pin component and the shoulder component is then performed based on these quantities. Specifically, when both the first condition (pin movement amount included in a first range) and the second condition (shoulder displacement amount included in a second range) are met, the pin component is driven back a predetermined amount from the contact surface. The origin alignment of the two components is then performed using the positions of the pin component and the shoulder component in this state as a reference. This ensures both the accuracy and efficiency of the origin alignment, and improves its safety.

[0117] The inventors conducted in-depth research and discovered that when the pin member further abuts the abutment surface while the shoulder member is already abutting it, the slight retraction of the shoulder member due to the pin member's contact, and the resulting positional deviations of the distal ends of the pin member and shoulder member, caused by this retraction, are uniquely determined under specific conditions. Specifically, it was found that the positional deviation is uniquely determined if the pin movement and shoulder displacement are within specific ranges. Based on this understanding, in this control method, the first condition (that the pin movement is within a first range) and the second condition (that the shoulder displacement is within a second range) are determined separately. If both conditions are confirmed to be met, the pin member is retracted by a predetermined return amount. This ensures that the position of the distal end of the retracted pin member is accurately aligned with the position of the distal end of the shoulder member. Furthermore, by aligning the origin of the pin member and shoulder member in this state, the accuracy of the origin alignment is improved, thereby enhancing the engagement performance of the friction stirring engagement device equipped with these pin members and shoulder members. For example, it can improve the performance of smoothly completing the joint.

[0118] Furthermore, by performing the action of sequentially abutting the shoulder member and pin member against the same contact surface, and determining the positions of the shoulder member and pin member in each stage as the first and second shoulder positions and the first and second pin positions, it is possible to determine whether the first and second conditions are met based on these positions. Moreover, if both conditions are met, retracting the pin member by a predetermined amount will align the positions of the pin member and shoulder member. Therefore, this approach automates a series of steps and facilitates easy origin alignment, improving both the efficiency and safety of the origin alignment process.

[0119] On the other hand, if at least the first condition is not met, the pin member retracts to a starting position away from the contact surface and repeats the same steps from that position. Therefore, it is possible to achieve the positional alignment of the pin member and the shoulder member as much as possible, and the probability of automatically achieving origin alignment can be increased.

[0120] Here, it is known that a large pin movement and a small shoulder displacement facilitate the stabilization of the aforementioned positional deviation, i.e., the positional deviation of the pin member and the distal ends of the shoulder member caused by the backward displacement of the shoulder member. Therefore, it is ideal to set the following: the first range is a range above a predetermined reference movement, the second range is a range below a predetermined reference displacement, and the starting position is a position at a distance above the reference movement from the abutment surface.

[0121] According to this configuration, it is possible to correctly determine whether the positional deviation is in a uniquely determined state based on whether the first and second conditions are met. Furthermore, even if the first condition is not met, the first condition will definitely be met if the pin member is retracted to the restart position, thus reducing the number of retries.

[0122] More ideally, in the third step, the pin component is driven in such a way that it moves at a constant speed after being accelerated to a specified target speed, and the reference movement is set to be a distance or more necessary to increase the moving speed of the pin component to the target speed.

[0123] According to this configuration, based on the fulfillment of the first condition, it is ensured that the pin component abuts against the contact surface at a constant speed. Therefore, the positional deviation when the first and second conditions are met can be stabilized more, and the accuracy of the origin alignment can be significantly improved.

[0124] Another aspect of the present invention relates to a friction stirring and joining device comprising: a pin member for rotating about an axis and moving forward and backward along the axis; a shoulder member disposed on the outer periphery of the pin member and for rotating about the axis and moving forward and backward along the axis; a zeroing control unit for aligning the origin of the pin member and the shoulder member; a joining control unit for joining the workpiece by rotating the pin member and the shoulder member while pressing them into the workpiece; and a storage unit for storing data; wherein the zeroing control unit is capable of performing: a first process, transferring... The shoulder member's position in the axial direction when its distal end abuts against a designated abutment surface is stored in the storage unit as a first shoulder position; the second process involves storing the pin member's initial position in the axial direction as a first pin position in the storage unit; the third process involves moving the pin member towards the abutment surface and storing the pin member's position in the axial direction when its distal end abuts against the abutment surface as a second pin position in the storage unit; the fourth process involves storing the position of the pin member as it abuts against the abutment surface. The position of the retracted shoulder member in the axial direction is stored as a second shoulder position in the storage unit; the fifth process determines whether the first condition that the distance between the first pin position and the second pin position, i.e., the pin movement amount, is included in a predetermined first range, and whether the second condition that the distance between the first shoulder position and the second shoulder position, i.e., the shoulder displacement amount, is included in a predetermined second range, is met; the sixth process, if the first and second conditions are met, causes the pin member to move from the abutment surface... The pin member is retracted by a predetermined amount, and the origin of the pin member and the shoulder member is aligned with reference to their respective positions in the axial direction after retraction; and, in the seventh process, if at least the first condition is not met, the pin member is retracted to a restart position that is farther away from the abutment surface than the first pin position; wherein, after the seventh process, the zeroing control unit uses the position of the pin member retracted to the restart position as the new first pin position and executes the processes after the second process again.

[0125] According to this friction stirring and bonding device, the same effect as the control method described above can be obtained.

Claims

1. A control method for a friction stirring and joining device, characterized in that, The friction stirring and joining device includes a pin member that rotates about an axis and moves forward and backward along the axis, and a shoulder member disposed on the outer periphery of the pin member and also rotates about the axis and moves forward and backward along the axis. The workpiece is joined by pressing it into the pin member while it rotates. The control method of the friction stirring and joining device includes: Step 1: Store the position of the shoulder member in the axial direction with the distal end of the shoulder member abutting against the designated abutting surface as the first shoulder position α1. Step 2: Store the initial position of the pin component in the axial direction as the first pin position β1; The third step is to move the pin member toward the abutting surface and store the position of the pin member in the axial direction when the distal end of the pin member abuts the abutting surface as the second pin position β2. Step 4: The position of the shoulder member in the axial direction as it retracts as the pin member abuts the abutment surface is stored as the second shoulder position α2. Step 5: Determine whether the first condition is met that the distance between the first pin position β1 and the second pin position β2, i.e., the pin movement β1-β2, is included in the first range above the predetermined reference movement Xβ, and whether the second condition is met that the distance between the first shoulder position α1 and the second shoulder position α2, i.e., the shoulder displacement α2-α1, is included in the second range below the predetermined reference displacement Xα. Step 6: If conditions 1 and 2 are met, the pin member is retracted from the abutment surface by a predetermined amount, and the origin alignment of the pin member and the shoulder member is performed based on their respective positions in the axial direction after retraction; and... Step 7: If at least the first condition is not met, retract the pin member to a new starting position that is farther away from the abutment surface than the first pin position; wherein... After step 7, the position of the pin member that has retreated to the restart position is used as the new first pin position, and the steps after step 2 are executed again.

2. The control method for the friction stirring and joining device according to claim 1, characterized in that, The restart position is a position that is more than or equal to the reference movement amount Xβ away from the contact surface.

3. The control method for the friction stirring and joining device according to claim 2, characterized in that, In step 3, the pin component is driven in such a way that it moves at a constant speed after being accelerated to a specified target speed. The reference movement amount Xβ is set to be a distance or more necessary to increase the moving speed of the pin member to the target speed.

4. A friction stir welding apparatus characterized by include: The pin component rotates about an axis and moves forward and backward along that axis; The shoulder member is disposed on the outer periphery of the pin member and is capable of rotation about the axis and forward and backward movement along the axis; The zeroing control unit aligns the origin of the pin component and the shoulder component. The engagement control unit engages the workpiece by rotating the pin member and the shoulder member while pressing them into the workpiece; and... The storage department stores data; among which, The zeroing control unit is capable of performing: The first process involves storing the position of the shoulder member in the axial direction, with the distal end of the shoulder member abutting against a designated abutting surface, as a first shoulder position α1 in the storage unit. The second process involves storing the initial position of the pin component in the axial direction as the first pin position β1 in the storage unit; The third process involves advancing the pin member toward the abutting surface and storing the position of the pin member in the axial direction when the distal end of the pin member abuts the abutting surface as the second pin position β2 in the storage unit. The fourth process involves storing the position of the shoulder member in the axial direction as a second shoulder position α2 in the storage unit, which is the position of the shoulder member that retracts as the pin member abuts the abutment surface. The fifth step involves determining whether the first condition is met: the distance between the first pin position β1 and the second pin position β2, i.e., the pin movement β1-β2, is included in a first range above a predetermined reference movement Xβ; and whether the second condition is met: the distance between the first shoulder position α1 and the second shoulder position α2, i.e., the shoulder displacement α2-α1, is included in a second range below a predetermined reference displacement Xα. The sixth process involves, if the first and second conditions are met, retracting the pin member from the abutment surface by a predetermined amount, and aligning the origins of the pin member and the shoulder member with reference to their respective positions in the axial direction after retraction; and... The seventh step involves, if at least the first condition is not met, retracting the pin member to a new starting position that is further away from the abutment surface than the first pin position; wherein... After the seventh process, the zeroing control unit will use the position of the pin member that has retreated to the restart position as the new first pin position and then execute the processes after the second process again.

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