Friction stir welding apparatus and friction stir welding method

Abstract

To provide a friction stir welding apparatus and a friction stir welding method capable of performing friction stir welding for the same member to be bonded multiple times by easily shifting the locus of the welding.SOLUTION: A friction stir welding apparatus includes: a welding tool; a spindle housing covering a spindle connected to the welding tool; a plurality of roll members provided on the spindle housing; and a guide rail for guiding the welding tool in a predetermined direction by contacting any of the roll members among the plurality of roll members and a guide surface of the guide rail. Further, the plurality of roll members is arranged in a manner that, when viewed from an axial direction of the welding tool, a distance from an axis of the welding tool to a position where one of the roll members is in contact with the guide surface is different from a distance from the axis of the welding tool to a position where another roll member is in contact with the guide surface.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a friction stir welding apparatus and a friction stir welding method. [Background technology]

[0002] Patent Document 1 discloses a friction stir welding method and a friction stir welding device in which a cylindrical welding tool is carried by an articulated robot arm, and the welding tool is rotated to generate frictional heat that stirs softened portions of the workpieces to join overlapping workpieces together. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 7212124 Summary of the Invention [Problem to be solved by the invention]

[0004] In friction stir welding, which is performed by holding a welding tool on an articulated robot arm, the trajectory of the friction stir welding may deviate from the target due to the reaction force from the workpieces to be welded, due to the low rigidity of the articulated robot arm. When performing friction stir welding on the same workpieces multiple times by shifting the welding trajectory, it is necessary to temporarily remove the guide rail that guides the welding tool in a specified direction, adjust the position, and then reattach the guide rail.

[0005] The present invention has been made in consideration of the above-mentioned problems, and its object is to provide a friction stir welding apparatus and a friction stir welding method that can easily perform friction stir welding on the same workpieces multiple times by shifting the welding trajectory. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems and achieve the object, the friction stir welding apparatus of the present invention is characterized in that a plurality of roll members are provided in a spindle housing that covers a spindle connected to a welding tool, a guide rail is provided that guides the welding tool in a predetermined direction by bringing any one of the plurality of roll members into contact with a guide surface, and the plurality of roll members are arranged so that, as viewed from the axial direction of the welding tool, the distances from the axis of the welding tool to the contact positions between each of the plurality of roll members and the guide surface are different.

[0007] As a result, the friction stir welding apparatus according to the present invention can easily perform friction stir welding on the same workpieces multiple times by shifting the welding trajectory.

[0008] Furthermore, a friction stir welding method according to the present invention is a friction stir welding method using the above-mentioned friction stir welding apparatus, characterized by comprising the steps of: performing a first friction stir welding of the workpieces by the welding tool by moving the welding tool while bringing any one of the plurality of roll members into contact with the guide surface; and, after performing the first friction stir welding, performing a second friction stir welding of the workpieces by moving the welding tool while bringing another one of the plurality of roll members into contact with the guide surface.

[0009] As a result, the friction stir welding method according to the present invention can easily perform friction stir welding of the same workpieces multiple times by shifting the welding trajectory.

[0010] In the above, when viewed from the axial direction of the welding tool, the guide rail may be positioned closer to the welding tool than the roll member that contacts the guide surface.

[0011] This allows the joining tool to receive a force in the direction of movement, and move along the guide rail while pulling the spindle housing with the roll member.

[0012] In the above, when viewed from the axial direction of the welding tool, the roll member that contacts the guide surface may be positioned closer to the welding tool than the guide rail.

[0013] This allows the joining tool to receive a force in the direction of movement, and move along the guide rail while the roll member pushes the spindle housing.

[0014] In the above, the trajectory of the first friction stir welding and the trajectory of the second friction stir welding may be linear, and the distance between the trajectories may be 5 mm or less.

[0015] This makes it possible to perform friction stir welding with small (low-cost) equipment, which can provide high joining strength. [Effects of the Invention]

[0016] The friction stir welding apparatus and the friction stir welding method according to the present invention have the advantage that friction stir welding of the same workpieces can be performed multiple times by easily shifting the welding trajectory. [Brief explanation of the drawings]

[0017] [Figure 1] Fig. 1(a) is a diagram showing how two workpieces are joined by a first friction stir welding using the friction stir welding apparatus according to embodiment 1. Fig. 1(b) is a diagram showing the welding tool in the process of performing the first friction stir welding, as viewed from the direction of axis AX. [Figure 2] Fig. 2(a) is a diagram showing how two workpieces are joined by a second friction stir welding using the friction stir welding apparatus according to embodiment 1. Fig. 2(b) is a diagram showing the welding tool in the process of performing the second friction stir welding, as viewed from the direction of axis AX. [Figure 3]Fig. 3(a) is a diagram showing the state of friction stir welding using a welding tool with a thick probe, Fig. 3(b) is a diagram showing the state of the first friction stir welding using a welding tool with a thin probe, and Fig. 3(c) is a diagram showing the state of the second friction stir welding using a welding tool with a thin probe. [Figure 4] Fig. 4(a) is a view of a welding tool viewed from the direction of the axis AX in a process of performing a first friction stir welding using the friction stir welding device according to embodiment 2. Fig. 4(b) is a view of a welding tool viewed from the direction of the axis AX in a process of performing a second friction stir welding using the friction stir welding device according to embodiment 2. [Figure 5] Fig. 5(a) is a view of a welding tool viewed from the direction of the axis AX in a process of performing a first friction stir welding by the friction stir welding apparatus according to embodiment 3. Fig. 5(b) is a view of a welding tool viewed from the direction of the axis AX in a process of performing a second friction stir welding by the friction stir welding apparatus according to embodiment 3. [Figure 6] Fig. 6(a) is a view of a welding tool viewed from the direction of the axis AX in a process of performing a first friction stir welding using the friction stir welding device according to embodiment 4. Fig. 6(b) is a view of a welding tool viewed from the direction of the axis AX in a process of performing a second friction stir welding using the friction stir welding device according to embodiment 4. DETAILED DESCRIPTION OF THE INVENTION

[0018] (Embodiment 1) A first embodiment of a friction stir welding apparatus and a friction stir welding method according to the present invention will be described below, although the present invention is not limited to this embodiment.

[0019] FIG. 1(a) is a diagram showing how two workpieces 51 and 52 are joined by a first friction stir welding using the friction stir welding apparatus 1 according to the first embodiment. FIG. 1(b) is a diagram showing the welding tool 10 as viewed from the direction of the axis AX during the first friction stir welding process. Note that FIGS. 1(a) and 1(b) show the X-axis, Y-axis, and Z-axis, which are perpendicular to each other. In this embodiment, the +X-axis and −X-axis directions are referred to as the X-axis directions, the +Y-axis and −Y-axis directions are referred to as the Y-axis directions, and the +Z-axis and −Z-axis directions are referred to as the Z-axis directions. The X-axis, Y-axis, and Z-axis in other drawings all correspond to the X-axis, Y-axis, and Z-axis in FIGS. 1(a) and 1(b).

[0020] Fig. 2(a) is a diagram showing how two workpieces 51 and 52 are joined by a second friction stir welding using the friction stir welding apparatus 1 according to embodiment 1. Fig. 2(b) is a diagram showing the welding tool 10 in the process of performing the second friction stir welding, as viewed from the direction of the axis AX.

[0021] In the friction stir welding apparatus 1 according to the first embodiment, two workpieces 51 and 52, which are members to be welded, are placed on the mounting table 40 with the workpieces overlapping in the thickness direction. Then, a welding tool 10 provided in the friction stir welding apparatus 1 is rotated at high speed while a probe 11, which will be described later, is pressed against the workpieces 51 and 52 and moved linearly in a predetermined direction, thereby friction stir welding the two workpieces 51 and 52.

[0022] The welding tool 10 is a cylindrical member used for friction stir welding, and has a probe 11 attached to its tip in the -Z direction. The probe 11 is located at the center of the -Z direction end face of the main body of the welding tool 10, and protrudes from the end face in the -Z direction. The probe 11 has a cylindrical external shape. The area around the probe 11 on the -Z direction end face of the welding tool 10 is called a shoulder portion 12. The welding tool 10 may be made of a common material used as a material for welding tools for friction stir welding, such as steel, cemented carbide, and ceramics.

[0023] A spindle, which is a rotation axis (not shown), is connected to the end face of the welding tool 10 in the +Z direction. When rotating the welding tool 10, the spindle is rotated around the axis AX of the welding tool 10 as the rotation center by a rotation drive device having a motor (not shown). The welding tool 10 moves in a predetermined direction in accordance with the movement of the rotation drive device. In this embodiment, for example, the rotation direction of the welding tool 10 is clockwise. The movement direction of the welding tool 10 is parallel to the +Y direction.

[0024] The friction stir welding apparatus 1 according to the first embodiment also includes a spindle housing 20, which is a cylindrical sleeve that is concentric with the spindle and covers the spindle. The spindle and the spindle housing 20 are capable of relative movement in the direction of the axis AX of the welding tool 10. The spindle housing 20 does not rotate relative to the rotation of the spindle caused by the rotary drive device, but is held by a holding member (not shown) so as to be rotatable about the axis AX of the welding tool 10 by manual operation by, for example, an operator.

[0025] Two cam followers 201, 202 are provided as multiple roll members on end surface 21 of spindle housing 20 in the −Z direction via pedestals 221, 222 and rotation shafts 211, 212. The cam followers 201, 202 are both disk-shaped and have the same diameter, and are rotatably supported by rotation shafts 211, 212, respectively, that are parallel to axis AX of the welding tool 10. Cam follower 201 (rotation shaft 211) is disposed radially inward of cam follower 202 (rotation shaft 212) of spindle housing 20.

[0026] In the friction stir welding apparatus 1 according to the first embodiment, for example, the welding tool 10, the spindle housing 20, the spindle, and the rotary drive device are attached to the tip of an articulated robot arm as a friction stir welding unit.

[0027] Moreover, in the friction stir welding apparatus 1 according to the first embodiment, a guide rail 30 is provided on a surface of the mounting table 40 on which the workpieces 51, 52 are placed. The guide rail 30 has a guide surface 31 that faces outward in the radial direction (X-axis direction) of the spindle housing 20 and extends in the Y-axis direction. The guide rail 30 moves the welding tool 10 (spindle housing 20) while bringing the outer circumferential surface of the cam follower 201 or the outer circumferential surface of the cam follower 202 into contact with the guide surface 31, thereby guiding the welding tool 10 (spindle housing 20) in the Y-axis direction as a predetermined direction.

[0028] Here, the shortest distance in the radial direction of the spindle housing 20 from the axis AX of the welding tool 10 to a contact position P1 between the outer circumferential surface of the cam follower 201 and the guide surface 31 is defined as distance L1. Also, the shortest distance in the radial direction of the spindle housing 20 from the axis AX of the welding tool 10 to a contact position P2 between the outer circumferential surface of the cam follower 202 and the guide surface 31 is defined as distance L2. In the friction stir welding apparatus 1 according to the first embodiment, the cam follower 201 (rotation shaft 211) and the cam follower 202 (rotation shaft 212) are arranged so that the distance L1 and the distance L2 are different, specifically, so that the distance L2 is longer than the distance L1.

[0029] 1(b), when viewed from the direction of the axis AX of the welding tool 10, the guide rail 30 is disposed closer to the welding tool 10 than the cam follower 201 in the radial direction of the spindle housing 20. For example, in the step of performing the first friction stir welding, an operator manually moves the spindle housing 20 in the direction of the axis AX or rotates it about the axis AX to position the guide rail 30 between the welding tool 10 and the cam follower 201 in the radial direction of the spindle housing 20 on the opposite side to the direction in which the welding tool 10 is about to move (the direction of arrow A in FIG. 1), with the cam follower 201 in contact with the guide surface 31.

[0030] 2(b), when viewed from the direction of the axis AX of the welding tool 10, the guide rail 30 is disposed closer to the welding tool 10 than the cam follower 202 in the radial direction of the spindle housing 20. For example, in the step of performing the second friction stir welding, an operator manually moves the spindle housing 20 in the direction of the axis AX or rotates it about the axis AX to position the guide rail 30 between the welding tool 10 and the cam follower 202 in the radial direction of the spindle housing 20 on the opposite side to the direction in which the welding tool 10 is about to move (the direction of arrow A in FIG. 2), with the cam follower 202 in contact with the guide surface 31.

[0031] Then, in the steps of performing the first and second friction stir welding, the welding tool 10 receives a force in the direction in which it tries to move (the direction of arrow A), and is configured to move along the guide rail 30 while the cam followers 201, 202 pull the spindle housing 20 in the direction of arrow A. Therefore, it is possible to prevent the trajectories of the first friction stir welding and the second friction stir welding from shifting from the target positions due to the reaction force from the workpieces 51, 52. As a result, in the friction stir welding apparatus 1 according to embodiment 1, it is not necessary to temporarily remove the guide rail 30, adjust its position, and then reattach it, and friction stir welding of the same workpieces 51, 52 can be easily performed by shifting the trajectories of the first friction stir welding and the second friction stir welding.

[0032] Furthermore, in the friction stir welding apparatus 1 according to the first embodiment, during the step of performing a first friction stir welding, the welding tool 10 (spindle housing 20) is moved along the guide surface 31 while the cam follower 201 is in contact with the guide surface 31 and the welding tool 10 is rotated at high speed to press the probe 11 against the workpieces 51 and 52. As a result, the trajectory of the first friction stir welding is located at a distance L1 from the guide surface 31 in the radial direction (X-axis direction) of the spindle housing 20. Next, in the friction stir welding apparatus 1 according to the first embodiment, during the step of performing a second friction stir welding after the step of performing the first friction stir welding, the welding tool 10 (spindle housing 20) is moved along the guide surface 31 while the cam follower 202 is in contact with the guide surface 31 and the welding tool 10 is rotated at high speed to press the probe 11 against the workpieces 51 and 52. As a result, the trajectory of the second friction stir welding is located at a distance L2 from the guide surface 31 in the radial direction (X-axis direction) of the spindle housing 20.

[0033] In the friction stir welding apparatus 1 according to embodiment 1, the trajectory of the first friction stir welding and the trajectory of the second friction stir welding are linear, and the distances L1 and L2 are set so that the distance between the trajectories is 5 mm or less.

[0034] Fig. 3(a) is a diagram showing a state of friction stir welding using a welding tool 10 with a thick probe 11. Fig. 3(b) is a diagram showing a state of a first friction stir welding using a welding tool 10 with a thin probe 11. Fig. 3(c) is a diagram showing a state of a second friction stir welding using a welding tool 10 with a thin probe 11.

[0035] To obtain high joint strength in friction stir welding, it is necessary to enlarge the friction stir portion of the workpieces 51 and 52 that are friction-stirred by the welding tool 10. Therefore, as shown in FIG. 3( a), if a welding tool 10 with a thick probe 11 is used, a large friction stir portion 53 can be obtained in the first friction stir welding. However, a large force is required to press the welding tool 10 with a thick probe 11 into the workpieces 51 and 52, which requires large (expensive) equipment. Therefore, a welding tool 10 with a thin probe 11, as shown in FIGS. 3( b) and 3( c), is used, which can apply less force to the workpieces 51 and 52 than a welding tool 10 with a thick probe 11. Then, the second friction stir welding is performed slightly shifted from the trajectory of the first friction stir welding so that the distance between the trajectory of the first friction stir welding and the trajectory of the second friction stir welding is 5 mm or less. As a result, in the friction stir welding apparatus 1 according to embodiment 1, a friction stir portion 53 of the same size as that obtained when a welding tool 10 with a thick probe 11 is used can be obtained using small (inexpensive) equipment, and friction stir welding can be performed that achieves high welding strength.

[0036] (Embodiment 2) A friction stir welding apparatus and a friction stir welding method according to a second embodiment of the present invention will be described below. Note that in this embodiment, the same configurations as those in the first embodiment will not be described as appropriate.

[0037] Fig. 4(a) is a view of the welding tool 10 seen from the direction of the axis AX in a process of performing a first friction stir welding by the friction stir welding apparatus 1 according to embodiment 2. Fig. 4(b) is a view of the welding tool 10 seen from the direction of the axis AX in a process of performing a second friction stir welding by the friction stir welding apparatus 1 according to embodiment 2.

[0038] In the friction stir welding apparatus 1 according to the second embodiment, two cam followers 203, 204 are provided as multiple roll members on the end surface 21 of the spindle housing 20 via a pedestal and rotation shafts 213, 214 (not shown). The cam followers 203, 204 are both disk-shaped and have the same diameter, and are rotatably supported by the rotation shafts 213, 214, respectively, which are parallel to the axis AX of the welding tool 10. The cam follower 203 (rotation shaft 213) is disposed outward in the radial direction of the spindle housing 20 than the cam follower 204 (rotation shaft 214).

[0039] Moreover, in the friction stir welding apparatus 1 according to the second embodiment, a guide rail 30 is provided on a surface of a mounting table 40 (not shown) on which the workpieces 51, 52 are placed, in the radial direction of the spindle housing 20, in the direction in which the welding tool 10 is about to move (the direction of arrow A in FIG. 4). The guide rail 30 has a guide surface 32 that faces inward in the radial direction (X-axis direction) of the spindle housing 20 and extends in the Y-axis direction. The guide rail 30 rotates the welding tool 10 at high speed while bringing the outer peripheral surface of the cam follower 201 or the outer peripheral surface of the cam follower 202 into contact with the guide surface 32, thereby pressing the probe 11 against the workpieces 51, 52 and moving the welding tool 10 (spindle housing 20), thereby guiding the welding tool 10 (spindle housing 20) in the Y-axis direction as a predetermined direction.

[0040] Here, the shortest distance in the radial direction of the spindle housing 20 from the axis AX of the welding tool 10 to a contact position P3 between the outer circumferential surface of the cam follower 203 and the guide surface 32 is defined as distance L3. Also, the shortest distance in the radial direction of the spindle housing 20 from the axis AX of the welding tool 10 to a contact position P4 between the outer circumferential surface of the cam follower 204 and the guide surface 32 is defined as distance L4. In the friction stir welding apparatus 1 according to the second embodiment, the cam follower 203 (rotation shaft 213) and the cam follower 204 (rotation shaft 214) are arranged so that the distance L3 and the distance L4 are different, specifically, so that the distance L4 is shorter than the distance L3.

[0041] In the step of performing the first friction stir welding, as seen from the direction of the axis AX of the welding tool 10, the cam follower 203 is disposed closer to the welding tool 10 in the radial direction of the spindle housing 20 than the guide rail 30, as shown in Fig. 4(a). For example, in the step of performing the first friction stir welding, an operator manually moves the spindle housing 20 in the direction of the axis AX or rotates it about the axis AX as the center of rotation, so that the cam follower 203 is positioned in contact with the guide surface 32 between the welding tool 10 and the guide rail 30 in the radial direction of the spindle housing 20, on the same side as the direction in which the welding tool 10 is about to move (the direction of arrow A).

[0042] 4(b), when viewed from the direction of the axis AX of the welding tool 10, the cam follower 204 is disposed closer to the welding tool 10 than the guide rail 30 in the radial direction of the spindle housing 20. For example, in the step of performing the second friction stir welding, an operator manually moves the spindle housing 20 in the direction of the axis AX or rotates it about the axis AX to position the cam follower 204 in contact with the guide surface 32 between the welding tool 10 and the guide rail 30 in the radial direction of the spindle housing 20, on the same side as the direction in which the welding tool 10 is about to move (the direction of arrow A).

[0043] As a result, in the steps of performing the first and second friction stir welding, the welding tool 10 receives a force in the direction in which it tries to move (the direction of arrow A), and is able to move along the guide rail 30 while the cam followers 201, 202 push the spindle housing 20 in the direction of arrow A. This makes it possible to prevent the trajectory 61 of the first friction stir welding and the trajectory 62 of the second friction stir welding from shifting from the target positions due to the reaction force from the workpieces 51, 52. As a result, in the friction stir welding apparatus 1 according to the second embodiment, it is not necessary to temporarily remove the guide rail 30, adjust its position, and then reattach it, and friction stir welding of the same workpieces 51, 52 can be easily performed by shifting the trajectory 61 of the first friction stir welding and the trajectory 62 of the second friction stir welding.

[0044] Furthermore, in the friction stir welding apparatus 1 according to the second embodiment, during the step of performing the first friction stir welding, the welding tool 10 (spindle housing 20) is moved along the guide surface 32 while the cam follower 203 is in contact with the guide surface 32. As a result, a trajectory 61 of the first friction stir welding is positioned at a distance L3 from the guide surface 32 in the radial direction (X-axis direction) of the spindle housing 20. Next, in the friction stir welding apparatus 1 according to the second embodiment, after the step of performing the first friction stir welding, during the step of performing the second friction stir welding, the welding tool 10 (spindle housing 20) is moved along the guide surface 32 while the cam follower 204 is in contact with the guide surface 32. As a result, a trajectory 62 of the second friction stir welding is positioned at a distance L4 from the guide surface 32 in the radial direction (X-axis direction) of the spindle housing 20.

[0045] In the friction stir welding apparatus 1 according to the second embodiment, the trajectory 61 of the first friction stir welding and the trajectory 62 of the second friction stir welding are linear, and the distances L3 and L4 are set so that the distance between the trajectories is 5 mm or less. As a result, the friction stir welding apparatus 1 according to the second embodiment can perform friction stir welding that can obtain high joint strength using small (inexpensive) equipment.

[0046] (Embodiment 3) Hereinafter, a friction stir welding apparatus and a friction stir welding method according to a third embodiment of the present invention will be described. Note that in this embodiment, the same configurations as those in the first embodiment will not be described as appropriate.

[0047] Fig. 5(a) is a view of the welding tool 10 seen from the direction of the axis AX in a process of performing a first friction stir welding by the friction stir welding apparatus 1 according to embodiment 3. Fig. 5(b) is a view of the welding tool 10 seen from the direction of the axis AX in a process of performing a second friction stir welding by the friction stir welding apparatus 1 according to embodiment 3.

[0048] In the friction stir welding apparatus 1 according to the third embodiment, four cam followers 205a, 205b, 206a, and 206b are provided as multiple roll members on the end surface 21 of the spindle housing 20 via pedestals and rotating shafts 215a, 215b, 216a, and 216b (not shown). The cam follower 205a and the cam follower 205b are arranged adjacent to each other to form a pair. The cam follower 206a and the cam follower 206b are also arranged adjacent to each other to form a pair. The pair of cam followers 205a and 205b and the pair of cam followers 26a and 26b face each other in the radial direction of the spindle housing 20, sandwiching the welding tool 10 therebetween.

[0049] Furthermore, in the friction stir welding apparatus 1 according to the third embodiment, a guide rail 30 is provided on a surface of a mounting table 40 (not shown) on which the workpieces 51, 52 are placed, in the radial direction of the spindle housing 20, in the direction in which the welding tool 10 is about to move (the direction of arrow A in FIG. 5 ). The guide rail 30 has a guide surface 32 that faces inward in the radial direction (X-axis direction) of the spindle housing 20 and extends in the Y-axis direction. The guide rail 30 rotates the welding tool 10 at high speed while bringing the outer peripheral surfaces of the cam followers 205a, 205b or the outer peripheral surfaces of the cam followers 206a, 206b into contact with the guide surface 32, thereby moving the welding tool 10 (spindle housing 20) and guiding the welding tool 10 (spindle housing 20) in the Y-axis direction as a predetermined direction.

[0050] Here, the shortest distance in the radial direction of the spindle housing 20 from the axis AX of the welding tool 10 to contact positions P51 and P52 between the outer circumferential surfaces of the cam followers 205a and 205b and the guide surface 32 is defined as a distance L5. Also, the shortest distance in the radial direction of the spindle housing 20 from the axis AX of the welding tool 10 to contact positions P61 and P62 between the outer circumferential surfaces of the cam followers 206a and 206b and the guide surface 32 is defined as a distance L6. In the friction stir welding apparatus 1 according to the third embodiment, the cam followers 205a and 205b (the rotation shafts 215a and 215b) and the cam followers 206a and 206b (the rotation shafts 216a and 216b) are arranged so that the distance L5 and the distance L6 are different, specifically, so that the distance L6 is shorter than the distance L5.

[0051] In the step of performing the first friction stir welding, as shown in FIG. 5( a), when viewed from the direction of the axis AX of the welding tool 10, the cam followers 205a, 205b are arranged closer to the welding tool 10 than the guide rail 30 in the radial direction of the spindle housing 20. For example, in the step of performing the first friction stir welding, an operator manually moves the spindle housing 20 in the direction of the axis AX or rotates it about the axis AX to position the cam followers 205a, 205b in contact with the guide surface 32 on the same side as the direction in which the welding tool 10 is to move (the direction of arrow A) and between the welding tool 10 and the guide rail 30 in the radial direction of the spindle housing 20. Then, in the step of performing the first friction stir welding, the welding tool 10 (spindle housing 20) is moved along the guide surface 32 by rotating the welding tool 10 at high speed while keeping the cam followers 205a, 205b in contact with the guide surface 32, thereby pressing the probe 11 against the workpieces 51, 52.

[0052] 5(b), when viewed from the direction of the axis AX of the welding tool 10, the cam followers 206a, 206b are disposed closer to the welding tool 10 than the guide rail 30 in the radial direction of the spindle housing 20. For example, in the step of performing the second friction stir welding, an operator manually moves the spindle housing 20 in the direction of the axis AX or rotates it about the axis AX to position the cam followers 206a, 206b in contact with the guide surface 32 between the welding tool 10 and the guide rail 30 in the radial direction of the spindle housing 20, on the same side as the direction in which the welding tool 10 is about to move (the direction of arrow A). Then, in the step of performing the second friction stir welding, the welding tool 10 (spindle housing 20) is moved along the guide surface 32 by rotating the welding tool 10 at high speed while keeping the cam followers 206a, 206b in contact with the guide surface 32 to press the probe 11 against the workpieces 51, 52.

[0053] As a result, in the step of performing the first friction stir welding, the welding tool 10 receives a force in the direction in which it tries to move (the direction of arrow A), and is able to move along the guide rail 30 while the cam followers 205a and 205b push the spindle housing 20 in the direction of arrow A. Similarly, in the step of performing the second friction stir welding, the welding tool 10 receives a force in the direction in which it tries to move (the direction of arrow A), and is able to move along the guide rail 30 while the cam followers 206a and 206b push the spindle housing 20 in the direction of arrow A. Therefore, it is possible to prevent the trajectory 61 of the first friction stir welding and the trajectory 62 of the second friction stir welding from shifting from the target positions due to the reaction force from the workpieces 51 and 52. Therefore, in the friction stir welding apparatus 1 of embodiment 3, there is no need to remove the guide rail 30, adjust its position, and then reattach it, and friction stir welding of the same workpieces 51 and 52 can be easily performed by shifting the trajectory 61 of the first friction stir welding and the trajectory 62 of the second friction stir welding.

[0054] Furthermore, in the friction stir welding apparatus 1 according to the third embodiment, the trajectory 61 of the first friction stir welding and the trajectory 62 of the second friction stir welding are linear, and the distances L5 and L6 are set so that the distance between the trajectories is 5 mm or less. As a result, the friction stir welding apparatus 1 according to the third embodiment can perform friction stir welding that can obtain high joint strength using small (inexpensive) equipment.

[0055] Furthermore, in the friction stir welding apparatus 1 according to embodiment 3, by bringing the outer peripheral surfaces of the pair of cam followers 205a, 205b or the outer peripheral surfaces of the pair of cam followers 206a, 206b into contact with the guide surface 32 of the guide rail 30, the spindle housing 20 does not rotate even if the rigidity of the mechanism (such as an articulated robot arm) that holds the welding tool 10 is low, and therefore the distance between the guide rail 30 and the welding tool 10 can be kept constant.

[0056] (Embodiment 4) A fourth embodiment of the friction stir welding apparatus and method according to the present invention will be described below. Note that in this embodiment, the same configurations as those in the first embodiment will not be described as appropriate.

[0057] Fig. 6(a) is a view of the welding tool 10 seen from the direction of the axis AX in a process of performing a first friction stir welding by the friction stir welding apparatus 1 according to embodiment 4. Fig. 6(b) is a view of the welding tool 10 seen from the direction of the axis AX in a process of performing a second friction stir welding by the friction stir welding apparatus 1 according to embodiment 4.

[0058] In the friction stir welding apparatus 1 according to the fourth embodiment, three cam followers 27a, 27b, and 27c are provided as a plurality of roll members on the end surface 21 of the spindle housing 20 via bases and rotation shafts 217a, 217b, and 217c (not shown). The cam followers 207a, 207b, and 207c are all disk-shaped and have the same diameter, and are rotatably supported by rotation shafts 217a, 217b, and 217c, respectively, that are parallel to the axis AX of the welding tool 10. The cam followers 207a, 207b, and 207c (rotation shafts 217a, 217b, and 217c) are arranged concentrically about the axis AX. In addition, in the circumferential direction on the end face 21 of the spindle housing 20, the distance between cam follower 207b (rotation shaft 217b) and cam follower 207c (rotation shaft 217c) is arranged to be larger than the distance between cam follower 207a (rotation shaft 217a) and cam follower 207b (rotation shaft 217b).

[0059] Furthermore, in the friction stir welding apparatus 1 according to the fourth embodiment, a guide rail 30 is provided on a surface of a mounting table 40 (not shown) on which the workpieces 51 and 52 are placed, in the radial direction of the spindle housing 20, in the direction in which the welding tool 10 is about to move (the direction of arrow A in FIG. 6 ). The guide rail 30 has a guide surface 32 that faces inward in the radial direction (X-axis direction) of the spindle housing 20 and extends in the Y-axis direction. The guide rail 30 guides the welding tool 10 (spindle housing 20) in the Y-axis direction as a predetermined direction by rotating the welding tool 10 at high speed while bringing the outer circumferential surfaces of the cam followers 207a and 207b or the outer circumferential surfaces of the cam followers 207b and 207c into contact with the guide surface 32.

[0060] 6(a), the shortest distance in the radial direction of the spindle housing 20 from the axis AX of the welding tool 10 to contact positions P71 and P72 between the outer circumferential surfaces of the cam followers 207a and 207b and the guide surface 32 is defined as a distance L7. Also, as shown in FIG. 6(b), the shortest distance in the radial direction of the spindle housing 20 from the axis AX of the welding tool 10 to contact positions P81 and P82 between the outer circumferential surfaces of the cam followers 207b and 207c and the guide surface 32 is defined as a distance L8. In the friction stir welding apparatus 1 according to the fourth embodiment, the cam followers 207a, 207b, and 207c (the rotation shafts 217a, 217b, and 217c) are arranged so that the distance L7 and the distance L8 are different.

[0061] 6(a), when viewed from the direction of the axis AX of the welding tool 10, the cam followers 207a, 207b are disposed closer to the welding tool 10 than the guide rail 30 in the radial direction of the spindle housing 20. For example, in the process of performing the first friction stir welding, an operator manually moves the spindle housing 20 in the direction of the axis AX or rotates it about the axis AX to position the cam followers 207a, 207b in contact with the guide surface 32 on the same side as the direction in which the welding tool 10 is to move (the direction of arrow A) and between the welding tool 10 and the guide rail 30 in the radial direction of the spindle housing 20. Then, in the process of performing the first friction stir welding, the welding tool 10 (spindle housing 20) is moved along the guide surface 32 by rotating the welding tool 10 at high speed with the cam followers 207a, 207b in contact with the guide surface 32 to press the probe 11 against the workpieces 51, 52.

[0062] 6(b), when viewed from the direction of the axis AX of the welding tool 10, the cam followers 207b and 207c are disposed closer to the welding tool 10 than the guide rail 30 in the radial direction of the spindle housing 20. For example, in the step of performing the second friction stir welding, an operator manually moves the spindle housing 20 in the direction of the axis AX or rotates it about the axis AX to position the cam followers 207b and 207c in contact with the guide surface 32 on the same side as the direction in which the welding tool 10 is about to move (the direction of arrow A) and between the welding tool 10 and the guide rail 30 in the radial direction of the spindle housing 20. Then, in the step of performing the second friction stir welding, the welding tool 10 is rotated at high speed with the cam followers 207b and 207c in contact with the guide surface 32 to press the probes 11 against the workpieces 51 and 52, while moving the welding tool 10 (spindle housing 20) along the guide surface 32.

[0063] As a result, in the step of performing the first friction stir welding, the welding tool 10 receives a force in the direction in which it tries to move (the direction of arrow A), and is able to move along the guide rail 30 while the cam followers 207a and 207b push the spindle housing 20 in the direction of arrow A. Similarly, in the step of performing the second friction stir welding, the welding tool 10 receives a force in the direction in which it tries to move (the direction of arrow A), and is able to move along the guide rail 30 while the cam followers 207b and 207c push the spindle housing 20 in the direction of arrow A. Therefore, it is possible to prevent the trajectory 61 of the first friction stir welding and the trajectory 62 of the second friction stir welding from shifting from the target positions due to the reaction force from the workpieces 51 and 52. Therefore, in the friction stir welding apparatus 1 of embodiment 4, there is no need to remove the guide rail 30, adjust its position, and then reattach it, and friction stir welding of the same workpieces 51 and 52 can be easily performed by shifting the trajectory 61 of the first friction stir welding and the trajectory 62 of the second friction stir welding.

[0064] Furthermore, in the friction stir welding apparatus 1 according to the fourth embodiment, the trajectory 61 of the first friction stir welding and the trajectory 62 of the second friction stir welding are linear, and the distances L7 and L8 are set so that the distance between the trajectories is 5 mm or less. As a result, the friction stir welding apparatus 1 according to the fourth embodiment can perform friction stir welding that can obtain high joint strength using small (inexpensive) equipment. [Explanation of symbols]

[0065] 1 Friction stir welding equipment 10 Joining Tools 20 Spindle housing 21 End face 30 guide rail 31,32 Guide surface 51,52 Work 61,62 locus 201, 202, 203, 204 Cam followers 205a, 205b Cam followers 206a, 206b Cam followers 207a, 207b, 207c Cam followers

Claims

1. A plurality of roll members are provided in a spindle housing that covers a spindle connected to the joining tool, a guide rail is provided that guides the welding tool in a predetermined direction by bringing any one of the plurality of roll members into contact with a guide surface, a friction stir welding apparatus characterized in that the plurality of roll members are arranged so that, as viewed from the axial direction of the welding tool, the distances from the axis of the welding tool to the contact positions between each of the plurality of roll members and the guide surface are different.

2. A friction stir welding method using the friction stir welding apparatus according to claim 1, a step of performing a first friction stir welding of workpieces by the welding tool by moving the welding tool while bringing any one of the plurality of roll members into contact with the guide surface; a step of performing a second friction stir welding on the workpieces by moving the welding tool while bringing another of the plurality of roll members into contact with the guide surface after performing a first friction stir welding; A friction stir welding method comprising:

3. 3. The friction stir welding method according to claim 2, wherein, when viewed from the axial direction of the welding tool, the guide rail is positioned closer to the welding tool than the roll member that contacts the guide surface.

4. 3. The friction stir welding method according to claim 2, wherein the roll member in contact with the guide surface is located closer to the welding tool than the guide rail when viewed from the axial direction of the welding tool.

5. 5. The friction stir welding method according to claim 2, wherein the trajectory of the first friction stir welding and the trajectory of the second friction stir welding are linear, and the distance between the trajectories is 5 mm or less.

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