JP6148222B2 - Friction stir welding method and friction stir welding apparatus - Google Patents

Description

  The present invention relates to a friction stir welding method and a friction stir welding apparatus for continuously joining a first workpiece and a second workpiece by moving a bobbin tool linearly or curvedly.

  Patent Document 1 discloses an FSW apparatus and a FSW method for performing Friction Stir Welding (FSW) using a bobbin tool (summary, [0001]). The bobbin tool 1 of Patent Document 1 uses an upper shoulder 10 (upper pressing member), a lower shoulder 11 (lower pressing member), and a stirring shaft 12 (base material stirring shaft) (summary, FIGS. 1 to 4). etc).

  In Patent Document 1, it is considered to start joining in a state in which a cylindrical filler 15 having the same diameter as the hole 8 is fitted to the stirring shaft 12 and the hole 8 is closed ([0038], FIG. 1 (C)).

  In addition, in Patent Document 1, a fitting hole 8A in which a spline groove-shaped rotation restricting portion 16 is provided on the inner peripheral surface is formed. Further, the filler is made of the same material as the taper (conical frustum) -shaped base material, which is fitted in the stirrer shaft 12 in a male-female shape with a fitting hole 8A and provided with a spline-projection-shaped rotation restricting portion 17 on the outer peripheral surface. Install 15A. Then, by fitting the bobbin tool 1 having the filler 15A into the fitting hole 8A, the rotation restricting portions 16 and 17 are fitted to each other, and the filler 15A and the base material are fitted by the taper portion that restricts the axial direction. The joint hole 8A is always fitted flush (FIG. 2 (A), [0039]).

JP 2004-216435 A

  As described above, in the bobbin tool 1 of Patent Document 1, the fitting hole 8A provided with the spline groove-shaped rotation restricting portion 16 is formed on the inner peripheral surface of the base material (first workpiece and second workpiece). In addition, a spline-projecting rotation restricting portion 17 is provided on the outer peripheral surface of the filler 15A (spacer) fitted into the fitting hole 8A and male and female. Thereby, rotation of 15 A of fillers is controlled.

  However, there is room for improvement in terms of strength for restricting rotation only by combining the rotation restricting portion 16 of the fitting hole 8A and the rotation restricting portion 17 of the filler 15A.

  The present invention has been made in consideration of the above-described problems, and is a friction stirrer that can reliably regulate the rotation of the spacer inside the through hole formed in the boundary part between the first workpiece and the second workpiece. An object is to provide a joining method and a friction stir welding apparatus.

  A friction stir welding method (FSW method) according to the present invention includes a first shoulder, a second shoulder disposed opposite to the first shoulder with a boundary between the first workpiece and the second workpiece, and the second shoulder. A friction stir welding method for friction stir welding of the first workpiece and the second workpiece using a bobbin tool having a stirrer shaft that stirs the boundary portion while supporting the first and second workpieces. A through-hole forming step of forming a through-hole that is non-circular when viewed in a direction toward the shoulder and that passes through the second shoulder at the boundary between the first workpiece and the second workpiece; and A spacer that is a non-circular column when viewed in the direction from the first shoulder toward the second shoulder is disposed between the first shoulder and the second shoulder and around the stirring shaft. The friction stir welding member is generated by starting the friction stir welding in a state in which the second shoulder is passed through the through hole and the spacer and the stirring shaft are disposed in the through hole. And a friction stir welding step.

  According to the present invention, the through hole and the spacer have a columnar shape that is non-circular when viewed from the first shoulder toward the second shoulder. Thereby, compared with the case where a through-hole and a spacer are circular when seeing toward a 2nd shoulder from a 1st shoulder, it becomes possible for a spacer to control rotation within a through-hole reliably.

In addition, since the through hole and the spacer are columnar, the through hole and the spacer can be easily processed. In addition, column shape here means the shape where the same cross section continues in the direction which goes to a 2nd shoulder from a 1st shoulder.
The spacers may have the same cross section in the direction from the first shoulder toward the second shoulder.

  The spacer arranging step may be performed before the second shoulder is passed through the through hole. As a result, with the spacer interposed between the first shoulder and the second shoulder, the through hole is passed through the second shoulder, and the first and second shoulders are arranged at the start position of the friction stir welding, and the friction is maintained as it is. Start stir welding. For this reason, the work of fixing the second shoulder to the stirring shaft after passing the through hole through the stirring shaft can be made unnecessary. Therefore, it is possible to improve workability when starting friction stir welding.

  The second shoulder is formed into a columnar shape or a cylindrical shape, and the through hole includes a circular hole portion having a diameter larger than the second shoulder, and a protruding hole portion protruding from the circular hole portion, and the spacer includes the A circular spacer portion fitted into the circular hole portion and a protruding spacer portion fitted into the protruding hole portion may be included, and the protruding hole portion and the protruding spacer portion may be arranged along the advancing direction of the stirring shaft. . Accordingly, it is possible to eliminate the boundary between the spacer and the first and second workpieces at least at a portion corresponding to the protruding hole while securing the spacer at the start of friction stir welding.

  The friction stir welding apparatus according to the present invention supports the first shoulder, the second shoulder disposed opposite to the first shoulder across the boundary between the first workpiece and the second workpiece, and the second shoulder. A bobbin tool having a stirring shaft that stirs the boundary, and is a columnar shape that is non-circular when viewed from the first shoulder toward the second shoulder, and before the start of friction stir welding A spacer is provided between the first shoulder and the second shoulder and around the stirring shaft.

  According to the present invention, it is possible to reliably regulate the rotation of the spacer inside the through hole formed in the boundary portion between the first workpiece and the second workpiece.

It is a block diagram which shows simply the structure of the friction stir welding system containing the friction stir welding apparatus which concerns on 1st Embodiment of this invention. It is a figure which shows a mode that a bobbin tool is moved to the starting position of FSW in the said friction stir welding system of 1st Embodiment. It is a top view which shows the 1st workpiece | work and 2nd workpiece | work in 1st Embodiment simply. In 1st Embodiment, it is a figure which shows simply the state which has arrange | positioned the said bobbin tool in the boundary part of the said 1st workpiece | work and the said 2nd workpiece | work. It is a top view of the spacer of a 1st embodiment. It is a flowchart of FSW in 1st Embodiment. It is a figure which shows a mode that a bobbin tool is moved to the starting position of FSW in the friction stir welding system containing the friction stir welding apparatus which concerns on 2nd Embodiment. It is a top view which shows the 1st workpiece | work and 2nd workpiece | work in 2nd Embodiment simply. It is a top view of the spacer of a 2nd embodiment. It is a top view which shows simply the 1st workpiece | work and 2nd workpiece | work which concern on a modification. It is a top view of the spacer which concerns on a modification.

A. First embodiment [A1. Configuration of friction stir welding system 10]
(A1-1. Overall configuration)
FIG. 1 shows a simplified configuration of a friction stir welding system 10 (hereinafter referred to as “FSW system 10”) including a friction stir welding apparatus 18 (hereinafter referred to as “FSW device 18”) according to the first embodiment of the present invention. It is a block diagram shown in FIG. In addition to the FSW device 18, the FSW system 10 includes a work transfer device 12 (hereinafter also referred to as “transfer device 12”), a work support device 14 (hereinafter also referred to as “support device 14”), and a punching device 16. Is provided.

  FIG. 2 is a diagram illustrating how the bobbin tool 30 is moved to the start position of the FSW in the FSW system 10 of the first embodiment. In FIG. 2, X1 and X2 indicate the front-rear direction (traveling direction of the bobbin tool 30), Y1 and Y2 indicate the left-right direction, and Z1 and Z2 indicate the up-and-down direction (the same applies to other drawings). An arrow 300 in FIG. 2 indicates the moving direction of the bobbin tool 30. In the FSW system 10, a first workpiece W1 (hereinafter also referred to as “first workpiece W1” or “work W1”) and a second workpiece W2 (hereinafter also referred to as “second workpiece W2” or “work W2”). FSW is performed on the boundary 302 of FIG.

(A1-2. Work transfer device 12)
The workpiece transfer device 12 includes, for example, a robot arm and a transfer control device (not shown), and transfers the first and second workpieces W1 and W2 to a predetermined position of the workpiece support device 14 based on an input operation from the operator 200. . Further, based on an input operation from the operator 200, the transport device 12 takes out the first and second workpieces W <b> 1 and W <b> 2 (hereinafter also referred to as “FSW member Wf”) that have finished the FSW from the workpiece support device 14. Transport to another process. Instead of the workpiece transfer device 12, the worker 200 can transfer the first and second workpieces W1 and W2. When there is a control device (system control device) that controls the entire FSW system 10, the operation of the work transfer device 12 may be performed based on a command from the system control device (work support device 14, hole The same applies to the opening device 16 and the FSW device 18.)

(A1-3. Work support device 14)
The work support device 14 includes, for example, a mounting table (not shown), a clamp device, a support control device, and the like, and fixes the first and second works W1 and W2 based on an input operation from the operator 200. Further, the support device 14 releases the fixation of the FSW member Wf based on an input operation from the worker 200. In addition, it is also possible for the worker 200 to perform a part of the work support device 14 (for example, fixing the first and second works W1 and W2).

(A1-4. Drilling device 16)
FIG. 3 is a plan view schematically showing the first workpiece W1 and the second workpiece W2 in the first embodiment. 3 is a virtual line (the same applies to FIGS. 5 and 8 to 11 described later). The drilling device 16 is, for example, a processing device including a processing drill (not shown), a drilling control device, and the like, and based on an input operation from the operator 200, the boundary portion 302 between the first and second workpieces W1 and W2. The through hole 304 (FIGS. 2 and 3) is formed.

  As shown in FIG. 3, the through hole 304 is non-circular in a plan view (when viewed downward in the axial direction of the bobbin tool 30) and has a size that allows the lower shoulder 52 described later to pass therethrough. As shown in FIGS. 2 and 3, the through hole 304 of the first embodiment has a quadrangular prism shape, and has a rectangular shape (particularly a square shape) in plan view (when viewed downward in the axial direction of the bobbin tool 30). I am doing.

  The through hole 304 includes a virtual cylindrical (circular shape in plan view) portion (circular hole portion 306) and a portion protruding from the circular hole portion 306 (protruding hole portion 308). The diameter of the circular hole portion 306 (the length of one side of the through hole 304) is larger than the diameter Dl of the lower shoulder 52 described later.

(A1-5. FSW device 18)
(A1-5-1. Entire FSW device 18)
The FSW device 18 performs FSW on the first and second workpieces W1 and W2. As shown in FIG. 1, the FSW device 18 includes a bobbin tool 30, a robot arm 32, an upper shoulder lifting mechanism 34, a shoulder rotation motor 36 (hereinafter also referred to as “motor 36”), and a lower shoulder attachment / detachment device 38. And an FSW control device 40 (hereinafter also referred to as “control device 40”).

(A1-5-2. Bobbin tool 30)
FIG. 4 is a diagram schematically showing a state in which the bobbin tool 30 is arranged at the boundary portion 302 between the first and second workpieces W1 and W2 in the first embodiment. As shown in FIG. 4, the bobbin tool 30 includes an upper shoulder 50 (upper pressing member, first rotating body), a lower shoulder 52 (lower pressing member, second rotating body), and a pin 54 (probe, stirring shaft). ) And a spacer 56.

  The upper shoulder 50 rotates while pressing the boundary portion 302 between the first and second workpieces W1 and W2 in the first direction (for example, the downward direction). The lower shoulder 52 rotates while pressing the boundary portion 302 between the first and second workpieces W1 and W2 in a second direction (for example, upward) opposite to the first direction. The upper shoulder 50 and the lower shoulder 52 of the first embodiment are each a columnar or cylindrical member. In the first embodiment, the upper shoulder 50 and the lower shoulder 52 have the same diameter, but may have different diameters. The upper shoulder 50 and the lower shoulder 52 are pressed against the boundary portion 302 between the first and second workpieces W1 and W2 in a rotating state to join the first and second workpieces W1 and W2.

  As shown in FIGS. 2 and 4, in the FSW device 18 of the first embodiment, the upper shoulder 50 and the lower shoulder 52 before starting the FSW sandwich the spacer 56.

  One end of the pin 54 is fixed to the lower shoulder 52, and the other end is connected to the output shaft of the shoulder rotation motor 36 (FIG. 1). The pin 54 supports the lower shoulder 52 and rotates together with the lower shoulder 52. Thereby, the pin 54 stirs and joins the first and second workpieces W1 and W2 (and the spacer 56). The pin 54 of the first embodiment has a columnar shape or a cylindrical shape, but may have other columnar shapes, a cylindrical shape, or the like.

  FIG. 5 is a plan view of the spacer 56 of the first embodiment. The spacer 56 is used to improve the workability of the FSW device 18, and as shown in FIGS. 2 and 4, before the start of the FSW, between the upper shoulder 50 and the lower shoulder 52 and around the pin 54. Placed in.

  As shown in FIG. 5, the spacer 56 includes a virtual columnar (circular shape in plan view) portion (circular spacer portion 60) and a portion protruding from the circular spacer portion 60 (protruding spacer portion 62). . The spacer 56 of the first embodiment has a rectangular tube shape (a square ring shape in plan view), and a through hole 64 through which the pin 54 passes is formed.

  The width Ws (Y1-Y2 direction) and the depth Ds (X1-X2 direction) of the spacer 56 in plan view are the same as or larger than the diameter Dl of the lower shoulder 52. The width Ws and the depth Ds also mean the diameter of the circular spacer portion 60. The thickness of the spacer 56 is set equal to the thickness of the first and second workpieces W1 and W2. As will be described later, the spacer 56 may have other shapes.

  The protruding spacer portion 62 has a function as a detent for preventing the spacer 56 from rotating when the rotational force from the upper shoulder 50 and the lower shoulder 52 is applied to the spacer 56. In the first embodiment, the rotation of the spacer 56 is restricted by the four protruding spacer portions 62.

(A1-5-3. Robot arm 32)
The robot arm 32 (FIG. 1) is for displacing the bobbin tool 30 (tool displacement mechanism), and includes a tool support portion 70, a tool displacement motor 72, an arm control portion 74, and the like. The tool support unit 70 supports the bobbin tool 30. By operating the tool displacement motor 72, the entire bobbin tool 30 (upper shoulder 50, lower shoulder 52 and pin 54) is displaced via the tool support 70. The arm control unit 74 controls the displacement of the tool support unit 70 via the tool displacement motor 72. A tool displacement mechanism (for example, a portal arm) other than the robot arm 32 may be used.

  In the first embodiment, the direction in which the robot arm 32 displaces the bobbin tool 30 (tool displacement direction) includes up and down (vertical direction), front and rear, and left and right. Alternatively, as the tool displacement direction, it is possible to omit up and down (vertical direction), front and rear, and left and right. In that case, the work support device 14 may be provided with a mechanism (work displacement mechanism) for displacing the first and second works W1 and W2 to compensate for the shortage of the robot arm 32.

(A1-5-4. Upper shoulder lifting mechanism 34)
The upper shoulder lifting mechanism 34 (FIG. 1) moves the upper shoulder 50 up and down with respect to the lower shoulder 52 and the pin 54, and includes an upper shoulder lifting motor 80. By operating the upper shoulder lifting motor 80, the upper shoulder 50 is displaced with respect to the lower shoulder 52 and the pin 54. Thereby, the distance D (FIG. 4) between the upper shoulder 50 and the lower shoulder 52 can be adjusted, and the first and second workpieces W1 and W2 having various thicknesses can be joined. The lower shoulder 52 and the pin 54 are moved up and down by the robot arm 32.

(A1-5-5, shoulder rotation motor 36)
The shoulder rotation motor 36 rotates the upper shoulder 50 and the lower shoulder 52 in response to a command from the FSW control device 40. A motor 36 for the upper shoulder 50 and a motor 36 for the lower shoulder 52 may be provided, and the rotation of the upper shoulder 50 and the rotation of the lower shoulder 52 may be controlled separately. When a plurality of motors 36 are provided, the rotation direction of the motors 36 can be either the same direction or the opposite direction. Further, the rotational speeds [rpm] of the plurality of motors 36 can be the same or different.

(A1-5-6. Lower shoulder attaching / detaching device 38)
The lower shoulder attaching / detaching device 38 includes, for example, a robot arm and an attaching / detaching control device (not shown), and attaches / detaches the lower shoulder 52 to / from the pin 54 based on a command from the FSW control device 40.

(A1-5-7. FSW control device 40)
The FSW control device 40 controls each part (robot arm 32, motors 36, 80, etc.) of the FSW device 18 and executes friction stir welding control (FSW control). In the FSW control of the first embodiment, the bobbin tool 30 is moved linearly or curvedly while the rotating bobbin tool 30 is pressed against the first work W1 and the second work W2. Thus, the first workpiece W1 and the second workpiece W2 are continuously joined.

  As shown in FIG. 1, the FSW control device 40 includes an input / output unit 90, a calculation unit 92, and a storage unit 94. The input / output unit 90 outputs a control signal to an inverter (not shown) disposed between a power source (not shown) and the motors 36, 72, 80. The calculation unit 92 controls each unit of the FSW device 18. The calculation unit 92 includes a displacement control unit 100 that controls the displacement of the whole or a part of the bobbin tool 30 via the robot arm 32 and the upper shoulder lifting motor 80, and the upper shoulder 50 and the lower shoulder 52 via the shoulder rotation motor 36. And a rotation control unit 102 for controlling the rotation of the motor.

[A2. Flow of FSW]
FIG. 6 is a flowchart of the FSW in the first embodiment. Although part of the processing shown in FIG. 6 is performed by the worker 200, part or all of the work performed by the worker 200 can be automatically performed by the FSW system 10.

  In step S1 of FIG. 6, the operator 200 operates the drilling device 16 to form a through hole 304 at the boundary 302 (FSW start position) between the first and second workpieces W1 and W2. The formation of the through hole 304 can also be performed after step S2 described later.

  In step S <b> 2, the worker 200 operates the transfer device 12 to place the first and second workpieces W <b> 1 and W <b> 2 on the workpiece support device 14. At this time, the operator 200 operates a gripping device (not shown) of the workpiece support device 14 to fix the first and second workpieces W1 and W2 so as to withstand the FSW.

  In step S <b> 3, the worker 200 removes the lower shoulder 52 and then places the spacer 56 between the upper shoulder 50 and the lower shoulder 52. Specifically, the operator 200 first removes the lower shoulder 52 from the pin 54. Next, the worker 200 arranges the spacer 56 so as to penetrate the pin 54 inside the spacer 56. Next, the worker 200 fixes the lower shoulder 52 to the pin 54 in a state where the spacer 56 is disposed around the pin 54. As a result, the spacer 56 is interposed between the upper shoulder 50 and the lower shoulder 52 (see FIG. 4).

  Note that the worker 200 can adjust the distance D (FIG. 4) between the upper shoulder 50 and the lower shoulder 52 to the thickness of the spacer 56 by operating the upper shoulder lifting motor 80 as necessary.

  In step S4, the operator 200 positions the bobbin tool 30 as a whole. Specifically, the operator 200 passes the lower shoulder 52 with respect to the through holes 304 of the first and second workpieces W1 and W2, and arranges the pins 54 and the spacers 56 in the through holes 304. 30 is positioned.

  Note that when the positioning (including posture control) of the bobbin tool 30 is automatically performed, for example, it can be performed using an image sensor. As the image sensor here, at least one of an image sensor (first image sensor) that acquires an image of the spacer 56 and an image sensor (second image sensor) that acquires an image of the through-hole 304 can be used. .

  The image of the spacer 56 is used by the FSW control device 40 to determine the posture of the spacer 56. The posture of the spacer 56 is used when a spacer mounting device (not shown) grips the spacer 56 and / or when the spacer 56 is inserted into the through hole 304. The spacer attachment device is a device for inserting the spacer 56 into the pin 54, and includes, for example, a robot arm, an attachment control device, etc. (not shown). Further, the image of the through hole 304 is used for determining the position and shape of the through hole 304 in the FSW control device 40. The position and shape of the through hole 304 are used when the spacer 56 is inserted into the through hole 304 (and when the through hole 304 is passed through the lower shoulder 52). The second image sensor may acquire an image of the boundary portion 302 before the through hole 304 is formed, and set a position at which the through hole 304 is formed using the image of the boundary portion 302.

  Alternatively, the initial position (machining start point Pst (target start point)) of the bobbin tool 30 at the start of FSW is set on the basis of the position (coordinates) of the first / second work W1, W2 or the work support device 14. The bobbin tool 30 may be positioned by placing it.

  In step S5, the FSW control device 40 executes FSW based on the input operation from the worker 200 (FSW control). Before the execution of FSW, in addition to the machining start point Pst of the bobbin tool 30, the coordinates of the machining end point Pgoal (target end point) and the force applied from the bobbin tool 30 to the workpieces W1 and W2 (target pressing force Fptar) The thicknesses of the workpieces W1 and W2 are set. Then, the FSW control device 40 controls the robot arm 32 and the motors 36 and 80 to join the first and second workpieces W1 and W2 by FSW to the machining end point Pgoal, thereby completing the FSW member Wf.

  More specifically, in the FSW control, the upper shoulder 50 and the lower shoulder 52 are rotated in a state where the boundary portion 302 of the workpieces W1 and W2 is sandwiched (or pressed) by the upper shoulder 50 and the lower shoulder 52. In this state, the bobbin tool 30 is moved linearly or curvilinearly to join the workpieces W1 and W2 continuously. For this reason, it becomes possible to expand a use rather than using FSW for what is called spot junction.

  Note that when the movement of the bobbin tool 30 is started, the bobbin tool 30 may be moved toward the machining end point Pgoal after once retracted in the direction opposite to the machining end point Pgoal. As a result, the boundary between the spacer 56 and the first and second workpieces W1 and W2 opposite to the machining end point Pgoal can be erased. Alternatively, when the movement of the bobbin tool 30 is started, the bobbin tool 30 is moved along the entire boundary between the spacer 56 and the first and second workpieces W1 and W2 (or so as to trace the outer periphery of the rectangular spacer 56). After that, the bobbin tool 30 may be moved toward the processing end point Pgoal. As a result, the entire boundary between the spacer 56 and the first and second workpieces W1 and W2 can be erased.

[A3. Effects in the first embodiment]
According to the first embodiment as described above, the through hole 304 and the spacer 56 are non-circular in plan view (when viewed from the upper shoulder 50 (first shoulder) toward the lower shoulder 52 (second shoulder)). (FIGS. 2, 3 and 5). Thereby, compared with the case where the through-hole 304 and the spacer 56 are circular in planar view, it becomes possible to restrict | limit rotation of the spacer 56 inside the through-hole 304 reliably.

  In addition, since the through holes 304 and the spacers 56 are columnar, the through holes 304 and the spacers 56 can be easily processed.

  In the first embodiment, the spacer 56 is disposed between the upper shoulder 50 and the lower shoulder 52 (S3 in FIG. 6) before the lower shoulder 52 passes through the through hole 304 (S4). As a result, the through hole 304 is passed through the lower shoulder 52 with the spacer 56 interposed between the upper shoulder 50 and the lower shoulder 52, and the upper shoulder 50 and the lower shoulder 52 are disposed at the FSW start position, and the FSW is left as it is. To start. For this reason, it is possible to eliminate the work of fixing the lower shoulder 52 to the pin 54 after passing the through hole 304 through the pin 54 (stirring shaft). Therefore, it is possible to improve workability when starting FSW.

B. Second Embodiment [B1. Difference from First Embodiment]
FIG. 7 shows a friction stir welding system 10A (hereinafter referred to as “FSW system 10A”) including a friction stir welding apparatus 18a (hereinafter referred to as “FSW device 18a”) according to the second embodiment. It is a figure which shows a mode that it moves to a starting position. An arrow 300a in FIG. 7 indicates the moving direction of the bobbin tool 30a. FIG. 8 is a plan view schematically showing the first workpiece W1 and the second workpiece W2 in the second embodiment. FIG. 9 is a plan view of the spacer 56a of the second embodiment.

  The FSW system 10A according to the second embodiment basically has the same configuration as the FSW system 10 according to the first embodiment. In the following, the same components are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the FSW system 10A of the second embodiment, the shape of the through hole 304a formed in the first and second workpieces W1 and W2 is different from the through hole 304 of the first embodiment. That is, the through hole 304 of the first embodiment has a quadrangular prism shape (rectangular shape in plan view) (FIGS. 2 and 3). On the other hand, the through hole 304a of the second embodiment has a columnar (circular shape in plan view) portion (circular hole portion 306a) and a single portion that protrudes from the circular hole portion 306a (projection hole portion 308a). (FIG. 8). The diameter of the circular hole portion 306 a is larger than the diameter Dl of the lower shoulder 52.

  Similarly, in the FSW system 10A of the second embodiment, the shape of the spacer 56a is different from the spacer 56 of the first embodiment. That is, the spacer 56 of the first embodiment has a rectangular tube shape (a square ring shape in plan view) (FIGS. 2 and 5). On the other hand, the spacer 56a of the second embodiment includes a cylindrical (annular in a plan view) portion (circular spacer portion 60a) and a single portion (projecting spacer portion 62a) protruding from the circular spacer portion 60a. (FIG. 9).

  The diameter Ds (FIG. 9) of the circular spacer portion 60a in plan view is the same as or larger than the diameter Dl of the lower shoulder 52. The protruding spacer 62a engages with the protruding hole 308a of the through hole 304a. Thereby, when the rotational force from the upper shoulder 50 and the lower shoulder 52 is applied to the spacer 56a, it functions as a detent portion that restricts the rotation of the spacer 56a. In the second embodiment, the rotation of the spacer 56a is restricted by only one protruding spacer portion 62a.

  As shown in FIGS. 7 and 8, the protruding hole portion 308a and the protruding spacer portion 62a are arranged along the traveling direction (X1 direction) of the bobbin tool 30a (or pin 54). Further, the protruding spacer portion 62a of the second embodiment has a width We (FIG. 9) smaller than the diameter of the pin 54 (the maximum rotation diameter when the pin 54 is not columnar or cylindrical). The protruding hole 308a is the same, and has a size that allows the protruding spacer 62a to be inserted. Thereby, after the bobbin tool 30a moves the position of the protrusion hole part 308a and the protrusion spacer part 62a, it becomes possible to eliminate the boundary between the protrusion hole part 308a and the protrusion spacer part 62a. Here, the width We means a length in a direction (Y1, Y2 direction) perpendicular to the traveling direction X1 of the bobbin tool 30a and perpendicular to the rotation axis of the bobbin tool 30a.

  Further, the length Le (FIG. 9) of the protruding spacer 62a is, for example, not less than 1/3 of the diameter Ds and not more than the diameter Ds of the circular spacer 60a. The protruding hole 308a is the same, and has a size that allows the protruding spacer 62a to be inserted. Here, the length Le means a length along the traveling direction X1 of the bobbin tool 30a. The thickness (Z1, Z2 direction) of the spacer 56a is set equal to the thickness of the first and second workpieces W1, W2.

  The flow of FSW is the same as in the first embodiment (FIG. 6).

[B2. Effect in Second Embodiment]
According to the second embodiment as described above, the following effects can be obtained in addition to or instead of the first embodiment.

  That is, according to the second embodiment, the lower shoulder 52 is formed in a cylindrical shape (FIGS. 7, 4 and the like). Further, the through hole 304a includes a circular hole portion 306a having a diameter larger than that of the lower shoulder 52 and a protruding hole portion 308a protruding from the circular hole portion 306a (FIG. 8). Further, the spacer 56a includes a circular spacer portion 60a fitted into the circular hole portion 306a and a protruding spacer portion 62a fitted into the protruding hole portion 308a (FIG. 9). Furthermore, the protruding hole portion 308a and the protruding spacer portion 62a are arranged along the traveling direction (X1 direction) of the pin 54 (stirring shaft) (FIGS. 7 and 8). As a result, it is possible to eliminate the boundary between the spacer 56a and the first and second workpieces W1 and W2 at least in a portion corresponding to the protruding hole 308a while securing the spacer 56a at the start of the FSW. .

C. Modifications Note that the present invention is not limited to the above-described embodiments, and various configurations can be adopted based on the description of the present specification. For example, the following configuration can be adopted.

[C1. FSW system 10, 10A (application target)]
In the FSW systems 10 and 10A of each of the embodiments described above, the first and second workpieces W1 and W2 have a flat plate shape and are joined in parallel (so-called butt joining) in the horizontal direction (FIGS. 2 and 7). However, for example, from the viewpoint of performing FSW with the two shoulders 50 and 52 sandwiching the first and second workpieces W1 and W2 (or from the viewpoint of the bobbin tools 30 and 30a), this is not limiting. For example, the first and second workpieces W1 and W2 may be arranged in parallel in a direction other than the horizontal direction (for example, the vertical direction). Further, the first and second workpieces W1 and W2 may not be flat. Furthermore, it is also possible to perform joining (so-called superposition joining) in a state where the main surfaces of the first and second workpieces W1 and W2 are superposed.

  From another viewpoint, in the FSW systems 10 and 10A of the above embodiments, the tool support 70 (FIG. 1) is disposed above the first and second workpieces W1 and W2, and the tool support 70 is attached to the tool support 70. The near shoulder was designated as the upper shoulder 50, and the shoulder far from the tool support portion 70 was designated as the lower shoulder 52. However, for example, from the viewpoint of performing FSW with the two shoulders 50 and 52 sandwiching the first and second workpieces W1 and W2 (or from the viewpoint of the bobbin tools 30 and 30a), this is not limiting. For example, the tool support 70 is disposed below the first and second workpieces W1 and W2, the shoulder close to the tool support 70 is set as the lower shoulder 52, and the shoulder far from the tool support 70 is set as the upper shoulder 50. Good.

[C2. Robot arm 32 and motors 36, 80]
In the above embodiment, the robot arm 32 and the motors 36 and 80 are used for controlling the bobbin tool 30 (FIG. 1). However, for example, from the viewpoint of linear movement (or curved movement) and rotation of the bobbin tool 30, this is not limiting.

  In each of the above embodiments, both the upper shoulder 50 and the lower shoulder 52 can be rotated by the single shoulder rotation motor 36 (FIG. 1). However, for example, from the viewpoint of using the spacers 56 and 56a or from the viewpoint of making the spacers 56 and 56a non-circular, the present invention is not limited thereto. For example, it is possible to provide the motor 36 separately for each of the upper shoulder 50 and the lower shoulder 52. Alternatively, it is possible to provide the motor 36 for only one of the upper shoulder 50 and the lower shoulder 52 so that only one of them can rotate.

  In each of the above embodiments, the upper shoulder lifting mechanism 34 for displacing the upper shoulder 50 with respect to the lower shoulder 52 and the pin 54 is provided (FIG. 1). However, for example, from the viewpoint of using the spacers 56 and 56a or from the viewpoint of making the spacers 56 and 56a non-circular, the upper shoulder lifting mechanism 34 can be omitted.

[C3. Through holes 304, 304a and spacers 56, 56a]
The through hole 304 of the first embodiment has a rectangular shape in plan view (FIG. 3), and the through hole 304a of the second embodiment has a circular hole portion 306a and a protruding hole portion 308a (FIG. 8). Similarly, the spacer 56 of the first embodiment has a rectangular shape in plan view (FIG. 5), and the spacer 56a of the second embodiment has a circular spacer portion 60a and a protruding spacer portion 62a (FIG. 9). However, for example, from the viewpoint of restricting the rotation of the spacers 56 and 56a by engaging the protruding holes 308 and 308a of the through-holes 304 and 304a, the shapes of the through-holes 304 and 304a and the spacers 56 and 56a are as follows. Not limited to.

  FIG. 10 is a plan view schematically showing the first workpiece W1 and the second workpiece W2 according to the modification. FIG. 11 is a plan view of a spacer 56b according to a modification. The dashed-dotted line in FIG.10 and FIG.11 is a virtual line.

  The through-hole 304b according to the modification includes a columnar (circular shape in plan view) part (a circular hole part 306a similar to the second embodiment) and a single part (a protruding hole part) protruding from the circular hole part 306a. 308b) (FIG. 10). Similarly, the spacer 56b according to the modification includes a cylindrical (annular in a plan view) portion (a circular spacer portion 60a similar to the second embodiment) and a single portion (a protrusion) protruding from the circular spacer portion 60a. Spacer part 62b).

  The protruding spacer portion 62a of the second embodiment as a whole had a width We smaller than the diameter of the pin 54 (FIG. 9). On the other hand, the protruding spacer portion 62b of the modification includes both a portion where the width We is smaller than the diameter of the pin 54 and a portion where the width We is larger.

  Instead of the above embodiments and modifications (FIGS. 10 and 11), the through holes 304, 304a, and 304b and the spacers 56, 56a, and 56b have a prismatic shape (triangular prism, pentagonal prism, hexagonal prism, It may be an octagonal column, a decagonal column, etc.

[C4. FSW]
In each of the above embodiments, the spacers 56 and 56a are arranged between the upper shoulder 50 and the lower shoulder 52 (S3 in FIG. 6), and then the bobbin tools 30 and 30a are arranged at the FSW start position (S4). However, for example, from the viewpoint of using the spacers 56 and 56a or from the viewpoint of making the spacers 56 and 56a non-circular, the present invention is not limited thereto. For example, after the upper shoulder 50 and the pin 54 are arranged at the FSW start position, the lower shoulder 52 can be detached from the pin 54 and the spacers 56 and 56a can be arranged.

  In each of the above embodiments, the case where the bobbin tools 30 and 30a are moved linearly has been described (FIGS. 2 and 7). However, for example, from the viewpoint of using the spacers 56 and 56a, the bobbin tools 30 and 30a can be moved in a curved manner.

DESCRIPTION OF SYMBOLS 10, 10A ... Friction stir welding system 18, 18a ... Friction stir welding apparatus 30, 30a ... Bobbin tool 50 ... Upper shoulder (1st shoulder)
52 ... Lower shoulder (second shoulder) 54 ... Pin (stirring shaft)
56, 56a, 56b ... spacer 60, 60a ... circular spacer 62, 62a, 62b ... protruding spacer 302 ... boundary 304, 304a, 304b ... through hole 306, 306a ... circular hole 308, 308a, 308b ... protruding Part W1 ... 1st work W2 ... 2nd work Wf ... FSW member

Claims (4)

A first shoulder, a second shoulder disposed opposite to the first shoulder across the boundary between the first workpiece and the second workpiece, and a stirring shaft that supports the second shoulder and stirs the boundary A friction stir welding method for friction stir welding the first workpiece and the second workpiece using a bobbin tool comprising:
A through hole that is non-circular when viewed in the direction from the first shoulder toward the second shoulder and through which the second shoulder passes is formed in the boundary portion between the first workpiece and the second workpiece. Through hole forming step,
A spacer disposing step of disposing a columnar spacer that is non-circular when viewed in a direction from the first shoulder toward the second shoulder, between the first shoulder and the second shoulder and around the stirring shaft; ,
A friction stir welding step for generating a friction stir welding member by starting the friction stir welding in a state where the second shoulder is passed through the through hole and the spacer and the stirring shaft are disposed in the through hole. And
The friction stir welding method according to claim 1, wherein all of the spacers have the same cross section in a direction from the first shoulder toward the second shoulder . In the friction stir welding method according to claim 1,
The spacer placement step is performed before passing the through hole through the second shoulder. A first shoulder, a second shoulder disposed opposite to the first shoulder across the boundary between the first workpiece and the second workpiece, and a stirring shaft that supports the second shoulder and stirs the boundary A friction stir welding method for friction stir welding the first workpiece and the second workpiece using a bobbin tool comprising:
A through hole that is non-circular when viewed in the direction from the first shoulder toward the second shoulder and through which the second shoulder passes is formed in the boundary portion between the first workpiece and the second workpiece. Through hole forming step,
A spacer disposing step of disposing a columnar spacer that is non-circular when viewed in a direction from the first shoulder toward the second shoulder, between the first shoulder and the second shoulder and around the stirring shaft; ,
A friction stir welding step in which the friction stir welding member is generated by starting the friction stir welding in a state where the second shoulder is passed through the through hole and the spacer and the stirring shaft are disposed in the through hole;
Have
The second shoulder is columnar or cylindrical,
The through hole includes a circular hole portion having a diameter larger than that of the second shoulder, and a protruding hole portion protruding from the circular hole portion,
The spacer includes a circular spacer portion that is fitted into the circular hole portion, and a protruding spacer portion that is fitted into the protruding hole portion,
The friction stir welding method, wherein the protruding hole portion and the protruding spacer portion are arranged along a traveling direction of the stirring shaft. The first shoulder,
A second shoulder disposed opposite to the first shoulder across a boundary between the first workpiece and the second workpiece;
A friction stir welding apparatus having a bobbin tool that includes a stirring shaft that supports the second shoulder and stirs the boundary portion;
A columnar shape that is non-circular when viewed from the first shoulder toward the second shoulder, and is fitted between the first shoulder and the second shoulder and around the stirring shaft before the start of friction stir welding. With spacers ,
The friction stir welding apparatus according to claim 1, wherein the spacers have the same cross section in the direction from the first shoulder toward the second shoulder .

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