Rotary tool, joining device, and joining method

Abstract

To provide a rotary tool capable of performing load control in the state of being attached to a machining center; and to provide a welding apparatus and a welding method.SOLUTION: A rotary tool 1 used for a welding apparatus performing friction stir welding of a member to be welded comprises: a body part 10; a stirring pin 60 inserted into the member to be welded to perform friction stir welding of the member to be welded; a shoulder 70 which is a separate component from the stirring pin 60 to press the member to be welded in the state of being in contact with the member to be welded; a first elastic member 61 which energizes the stirring pin 60 toward a tip side in an axial direction of a rotation axis 12; and a regulation member 100 which regulates movement of the stirring pin 60 to a base end side in the axial direction of the rotation axis 12. The first regulation member 100 regulates movement of the stirring pin 60 so that a deformation quantity generated in the first elastic member 61 with movement of the stirring pin 60 may not exceed a maximum allowable quantity of the first elastic member 61.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a rotary tool, a joining device, and a joining method used for friction stir joining.

Background Art

[0002] As joining devices for performing friction stir joining, in order to control the penetration amount of a rotary tool with respect to a member to be joined, those performing load control and those performing position control are known. Load control is mainly used in joining devices by a robot (robot arm), and position control is mainly used in joining devices by a machining center (MC).

[0003] As a joining device that performs load control, for example, there is one disclosed in Patent Document 1. The joining device of Patent Document 1 controls the press-fitting depth of a shoulder member or a pin member into an object to be joined in order to obtain good joining quality with suitable accuracy according to joining conditions. Such a joining device controls the relative position of the pin member with respect to the shoulder member based on a press-fitting reference point set by a press-fitting reference point setting unit in order to control the press-fitting depth. The joining device includes a pressure detection unit, a pressure reference point setting unit, a tool drive control unit, etc. in order to perform the above control. Further, the tool drive unit includes a rotation drive unit, a pin drive unit, a shoulder drive unit, a clamp drive unit (elastic member: coil spring), etc.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Since the joining device of Patent Document 1 performs load control, its structure is complex and expensive. Therefore, in recent years, there has been a demand for a rotary tool that can be mounted on a relatively inexpensive MC that can only perform position control and can perform load control.

[0006] From such a perspective, an object of the present invention is to provide a rotary tool, a joining device, and a joining method that can perform load control while being mounted on a machining center.

Means for Solving the Problems

[0007] The present invention for solving the above problems is a rotary tool used in a joining device for friction stir joining of a member to be joined, comprising: a main body having a fixing portion attached and fixed to the joining device and a rotating shaft for transmitting a rotational force from the joining device; a stirring pin disposed on the main body so as to be rotatable and movable in the axial direction of the rotating shaft in response to the rotational force received from the main body, inserted into the member to be joined, and performing friction stirring on the member to be joined; a shoulder configured separately from the stirring pin, disposed on the main body so as not to receive the rotational force from the main body and movable separately from the stirring pin in the axial direction of the rotating shaft, and pressing the member to be joined in a state of contacting the member to be joined; a first elastic member for biasing the stirring pin toward the tip side in the axial direction of the rotating shaft; and a first restricting member for restricting the movement of the stirring pin toward the base end side in the axial direction of the rotating shaft. The first restricting member restricts the movement of the stirring pin so that the amount of deformation generated in the first elastic member as the stirring pin moves does not exceed the maximum allowable capacity of the first elastic member.

[0008] Further, it preferably includes a second elastic member for biasing the shoulder toward the tip side in the axial direction of the rotating shaft, and a second restricting member for restricting the movement of the shoulder toward the base end side in the axial direction of the rotating shaft. The second restricting member restricts the movement of the shoulder so that the amount of deformation generated in the second elastic member as the shoulder moves does not exceed the maximum allowable capacity of the second elastic member.

[0009] Further, the main body portion further includes a hollow cylindrical first holder attached to the rotation shaft, and a first slide shaft that is slidably accommodated in the central portion of the first holder in the rotation shaft direction and rotates synchronously with the first holder. The stirring pin is provided at the tip of the first slide shaft, and the first slide shaft is biased toward the tip side of the stirring pin via the first elastic member. It is preferable that the first restricting member restricts the first slide shaft from moving toward the proximal end side in the axial direction of the rotation shaft.

[0010] Further, the main body portion further includes a hollow cylindrical second holder provided to be relatively rotatable on the outer periphery of the first holder, and a second slide shaft that is slidably accommodated in the second holder in the axial direction of the rotation shaft. The shoulder is provided at the tip of the second slide shaft, and the second slide shaft is biased toward the tip side of the shoulder via the second elastic member. It is preferable that the second restricting member restricts the second slide shaft from moving toward the proximal end side in the axial direction of the rotation shaft.

[0011] Further, the first restricting member is provided in the first holder, and as the first slide shaft moves, the proximal end portion of the first slide shaft, the bottom portion on the proximal end side of the first holder, and the first restricting member come into contact with each other, thereby preferably restricting the movement of the first slide shaft.

[0012] Further, the second restricting member is provided in the second holder, and as the second slide shaft moves, the proximal end portion of the second slide shaft, the bottom portion on the proximal end side of the second holder, and the second restricting member come into contact with each other, thereby preferably restricting the movement of the second slide shaft.

[0013] Further, the first restricting member is provided at the bottom portion on the proximal end side of the first holder, and as the first slide shaft moves, the proximal end portion of the first slide shaft comes into contact with the first restricting member, thereby preferably restricting the movement of the first slide shaft.

[0014] Further, it is preferable that the second restricting member is provided at the bottom portion on the proximal end side of the second holder, and the movement of the second slide shaft is restricted by the contact between the proximal end portion of the second slide shaft and the second restricting member as the second slide shaft moves.

[0015] Further, it is preferable that the first restricting member is provided at the proximal end portion of the first slide shaft, and the movement of the first slide shaft is restricted by the contact between the bottom portion on the proximal end side of the first holder and the first restricting member as the first slide shaft moves.

[0016] Further, it is preferable that the second restricting member is provided at the proximal end portion of the second slide shaft, and the movement of the second slide shaft is restricted by the contact between the bottom portion on the proximal end side of the second holder and the second restricting member as the second slide shaft moves.

[0017] Further, it is preferable that the first restricting member is provided on the outer peripheral surface of the first slide shaft, and the movement of the first slide shaft is restricted by the contact between the first restricting member and the middle portion of the first holder as the first slide shaft moves.

[0018] Further, it is preferable that the second restricting member is provided on the outer peripheral surface of the second slide shaft, and the movement of the second slide shaft is restricted by the contact between the second restricting member and the middle portion of the second holder as the second slide shaft moves.

[0019] Further, it is preferable that the first restricting member is provided on the outer peripheral surface of the first slide shaft, and the movement of the first slide shaft is restricted by the contact between the first restricting member and the tip portion of the first holder as the first slide shaft moves.

[0020] Further, it is preferable that the second restricting member is provided on the outer peripheral surface of the second slide shaft, and the movement of the second slide shaft is restricted by the contact between the second restricting member and the tip portion of the second holder as the second slide shaft moves.

[0021] Further, it is preferable that the first restricting member is provided at the tip of the first slide shaft, and the movement of the first slide shaft is restricted by contact between the first restricting member and the tip of the first holder as the first slide shaft moves.

[0022] Also, it is preferable that the second restricting member is provided at the tip of the second slide shaft, and the movement of the second slide shaft is restricted by contact between the second restricting member and the tip of the second holder as the second slide shaft moves.

[0023] Further, it is preferable that the stirring pin is the first restricting member, and the movement of the first slide shaft is restricted by contact between the stirring pin and the tip of the first holder as the first slide shaft moves.

[0024] Also, it is preferable that the shoulder is the second restricting member, and the movement of the second slide shaft is restricted by contact between the shoulder and the tip of the second holder as the second slide shaft moves.

[0025] Further, the present invention is a joining device including the rotary tool according to any one of claims 1 to 18, comprising power means for outputting a rotational force transmitted to the rotary shaft of the rotary tool, and position control means for holding the fixed portion of the rotary tool and performing position control of the rotary tool, wherein the rotary tool is moved by the position control means to a predetermined height position with respect to the member to be joined, the stirring pin is inserted into the member to be joined, and friction stir joining of the member to be joined is performed.

[0026] Further, the present invention is characterized in that the rotary tool according to any one of claims 1 to 18 is moved to a predetermined height position with respect to the member to be joined, the stirring pin is inserted into the member to be joined, and friction stir joining of the member to be joined is performed.

Advantages of the Invention

[0027] According to the rotary tool, joining device, and joining method of the present invention, load control using an elastic member can be performed. Further, according to the rotary tool, joining device, and joining method of the present invention, even for a relatively hard workpiece to be joined, the stirring pin can be inserted while using the elastic member.

Brief Description of the Drawings

[0028]

Figure 1

Figure 2

Figure 3

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Figure 10

Figure 11

Figure 12

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Figure 14

Figure 15

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Figure 17

Figure 18

Embodiments for Carrying Out the Invention

[0029] Embodiments of the present invention will be described with appropriate reference to the drawings. The present invention is not limited to only the following embodiments. Also, the components in the embodiments can be appropriately combined in part or in whole. Furthermore, the drawings are for conceptually explaining the present invention, and the dimensions and ratios of the components shown may be different from the actual ones in some cases.

[0030] [1. First Embodiment] [1-1. Rotary Tool] First, the configuration of the rotary tool according to the present embodiment will be described. As shown in FIG. 1, the rotary tool 1 according to the present embodiment is used in a joining device that performs friction stir joining of the joined member 2 (see FIG. 5), and is inserted into the butting portion of the joined member 2 while rotating. Such a rotary tool 1 includes a main body portion 10, a stirring pin 60, a shoulder 70, a first elastic member 61, and a first restricting member 100. Further, the rotary tool 1 includes a second elastic member 71 and a second restricting member 110. Furthermore, the rotary tool 1 includes a holding portion 80.

[0031] <Main Body Portion> The main body portion 10 is a portion fixed to a joining device 3 such as a machining center, etc., and includes a fixing portion 11 and a rotating shaft 12. The fixing portion 11 is a portion that is attached and fixed to the joining device 3, and has a cylindrical shape. The fixing portion 11 is a chuck mechanism, and by cooperating with a paired chuck mechanism provided on the joining device 3, the fixing portion 11 can be detachably fixed to the joining device. Examples of the chuck mechanism include a groove provided in the fixing portion 11 and a claw provided on the joining device 3 that fits into and sandwiches the groove on the fixing portion 11 side. The rotating shaft 12 is connected and provided on the other end side (the lower side in FIG. 1), which is the side of the fixing portion 11 that is attached to the joining device 3. The rotating shaft 12 has a cylindrical shape. The rotating shaft 12 is a portion that transmits the rotational force from the joining device 3 to the stirring pin 60, and is connected to a rotating shaft (not shown) of the joining device 3 via the fixing portion 11.

[0032] As also shown in FIGS. 2 and 3, the main body portion 10 further includes a first holder 21, a first slide shaft 31, a second holder 41, and a second slide shaft 51.

[0033] <First Holder> The first holder 21 is attached to the rotating shaft 12, rotates synchronously with the rotating shaft 12, and is a portion that supports the stirring pin 60. The first holder 21 has a bottomed cylindrical shape (hollow cylindrical shape), and a first storage recess 22 into which the first slide shaft 31 is inserted is formed inside. The first storage recess 22 has a cylindrical shape and opens toward the stirring pin 60 side (the lower side in FIG. 1). A key groove 23 is formed in the cylindrical body portion of the first holder 21 (the outer peripheral edge portion of the first storage recess 22). The key groove 23 is formed in an elongated oval shape along the axial direction of the rotating shaft 12 (the vertical direction in FIG. 1) and penetrates from the outer peripheral surface to the inner peripheral surface of the first holder 21. The key groove 23 does not have to penetrate the cylindrical body portion, and may be formed in a groove shape on the inner peripheral surface of the cylindrical body portion. The key grooves 23 are arranged at 180° intervals in the circumferential direction of the cylindrical body portion and are formed at two locations facing each other. Note that the number of key grooves 23 is not limited to 2, and may be 1 or 3 or more.

[0034] <First slide shaft> The first slide shaft 31 is slidably accommodated in the first storage recess 22 at the center of the first holder 21 in the rotation axis direction (the vertical direction in FIG. 1), and is a part that rotates synchronously (rotates together) with the first holder 21. The first slide shaft 31 has a cylindrical shape and has an outer diameter that can be accommodated in the first storage recess 22. A key 32 that protrudes outward is provided on the outer peripheral surface of the first slide shaft 31. The key 32 is fixed at the base end portion of the first slide shaft 31 (the end portion on the back side of the first storage recess 22: the upper end portion in FIG. 1) at a position corresponding to the key groove 23 and is inserted into the key groove 23. The key 32 has an oblong shape that is long in the rotation axis direction, has a width dimension equivalent to that of the key groove 23, and has a length dimension shorter than the longitudinal dimension of the key groove 23. That is, the key 32 fits in the width direction of the key groove 23 and is movable in the longitudinal direction. Note that the shape of the key 32 is not limited to an oblong shape, and other shapes such as a circular shape, an elliptical shape, an oblong shape, or a rectangular shape may be used as long as it has a width dimension equivalent to that of the key groove 23. A stirring pin 60 is integrally provided at the tip end portion of the first slide shaft 31 (the end portion on the side away from the joining device 3: the lower end portion in FIG. 1). Therefore, when the stirring pin 60 is biased toward the tip end side by the first elastic member 61, the first slide shaft 31 is biased toward the tip end side.

[0035] <Second holder> The second holder 41 is a cylindrical (hollow cylindrical) part provided so as to be relatively rotatable on the outer periphery of the first holder 21, and is a part that supports the shoulder 70. A bearing 47 is interposed between the second holder 41 and the rotating shaft 12. The bearing 47 is arranged so as to surround the rotating shaft 12. Thereby, the second holder 41 is provided so as to be relatively rotatable with respect to the rotating shaft 12. Since the first holder 21 and the second holder 41 are relatively rotatable, the first holder 21 is rotatable inside the second holder 41. The cylindrical body of the second holder 41 is formed thicker than the cylindrical body of the first holder 21. A plurality of second storage recesses 42 into which the second slide shaft 51 is inserted are formed in the cylindrical body of the second holder 41. In the present embodiment, the second storage recesses 42 are formed at four locations at a 90° pitch in the circumferential direction of the cylindrical body. The second storage recess 42 has a cylindrical shape and opens toward the shoulder 70 side (lower side in FIG. 1). A key groove 43 is formed in the outer peripheral edge of the second storage recess 42. The key groove 43 is formed in an elongated oval shape along the axial direction of the rotating shaft 12 (vertical direction in FIG. 1) and penetrates from the inner peripheral surface of the second storage recess 42 to the outer peripheral surface of the second holder 41. Note that the key groove 43 does not have to penetrate, and may be formed in a groove shape on the inner peripheral surface of the second storage recess 42. The key groove 43 is formed at one location on the outer peripheral surface side of the cylindrical body of the second holder 41 in each second storage recess 42. Further, the number of the second storage recesses 42 is not limited to four, and may be one, or may be two or five or more.

[0036] A skirt portion 44 that covers the outer peripheral portion of the shoulder 70 is formed at the lower portion of the second holder 41. A shoulder storage recess 45 in which the stirring pin 60 and the upper portion of the shoulder 70 are stored is formed inside the skirt portion 44. The bottom 45a (upper end surface in FIG. 1, tip of the second holder 41) on the proximal end side of the shoulder storage recess 45 is flush with the tip 21a of the first holder 21. Note that the bottom 45a (upper end surface in FIG. 1) of the shoulder storage recess 45 and the tip 21a of the first holder 21 do not have to be flush.

[0037] <Second slide shaft> The second slide shaft 51 is a part that is slidably housed in the second storage recess 42 of the second holder 41 in the direction of the rotation axis. The second slide shaft 51 has a cylindrical shape and an outer diameter that can be housed in the second storage recess 42. A key 52 that protrudes outward is provided on the outer peripheral surface of the second slide shaft 51. The key 52 is fixed at the end of the second slide shaft 51 (the end on the proximal end side of the second storage recess 42: the upper end in FIG. 1) at a position corresponding to the key groove 43 and is inserted into the key groove 43. The key 52 has an oblong shape that is long in the rotation axis direction, has a width dimension equivalent to that of the key groove 43, and has a length dimension shorter than the longitudinal dimension of the key groove 43. That is, the key 52 fits in the width direction of the key groove 43 and is movable in the longitudinal direction. The key 52 can be inserted from the outside of the key groove 43 and fixed to the outer peripheral surface of the second slide shaft 51 in a state where the second slide shaft 51 is inserted into the second storage recess 42. The shape of the key 52 is not limited to an oblong shape, and other shapes such as a circular shape, an elliptical shape, an oblong ellipse, or a rectangular shape may be used as long as it has a width dimension equivalent to that of the key groove 43. A shoulder 70 is integrally provided at the tip of the second slide shaft 51 (the end on the side away from the joining device 3: the lower end in FIG. 1).

[0038] <Stirring pin> The stirring pin 60 is a part that receives the rotational force from the main body part 10, rotates and is inserted into the joined member, and performs friction stirring on the joined member. The stirring pin 60 is formed in a cylindrical shape from, for example, tool steel. The tip 62 (the lower end in FIG. 1) of the stirring pin 60 tapers toward the tip. The tip of the tip 62 of the stirring pin is in the shape of a flat surface orthogonal to the axial direction. The stirring pin 60 is integrally formed with the first slide shaft 31 and moves in the axial direction of the rotation axis by the sliding movement of the first slide shaft 31. The stirring pin 60 has a larger diameter than the first slide shaft 31, and a base end portion 63 is formed at the connecting portion between the stirring pin 60 and the first slide shaft 31 (the base end portion of the stirring pin 60).

[0039] <First elastic member> The first elastic member 61 is a part that biases the stirring pin 60 toward the tip side with respect to the axial direction of the rotating shaft 12. The first elastic member 61 is constituted by, for example, a coil spring, and is mounted between the base end portion 31b of the first slide shaft 31 and the bottom portion 22a of the first storage recess 22 in the first storage recess 22. The first elastic member 61 is capable of biasing the stirring pin toward the tip side against the force received from the stirring pin 60 side.

[0040] The elasticity of the first elastic member 61 is such that when the stirring pin 60 is inserted into the joined member 2 made of at least one material selected from the group consisting of aluminum, copper, magnesium, and alloys thereof with a predetermined pushing load, within a predetermined range within the entire movable range of the stirring pin 60 by the first elastic member 61 (the movable length of the key 32 in the key groove 23), the stirring pin 60 is displaced and inserted into the joined member 2.

[0041] For example, when the first elastic member 61 is a coil spring and the load applied to the first elastic member 61 is inserted at 100 kg to 5 t, the deflection amount of the first elastic member 61 is set to be deformed in the range of 0 to 30% with respect to the free length of the first elastic member 61, and the stirring pin 60 is inserted into the joined member 2. Thereby, when the stirring pin 60 is pushed into the joined member 2 at a constant height, even when the height of the joined member 2 changes, the first elastic member 61 deforms in accordance with the change of the joined member 2, making it easier to keep the insertion amount of the stirring pin 60 constant.

[0042] Note that the first elastic member 61 is not limited to a coil spring, and may be a metal spring such as a leaf spring or a disc spring, or a polymer elastic body (elastomer) such as rubber, a polymer resin, or a sponge-like resin. Further, the first elastic member 61 may be a fluid spring using pneumatic pressure, gas pressure, or hydraulic pressure, or a magnetic spring using magnetic force or electromagnetic force.

[0043] The first elastic member 61 may be set to satisfy the relationship between the amount of deformation and the elastic modulus when the stirring pin 60 is inserted to a predetermined depth, taking into account the joining conditions. Examples of the joining conditions that affect the setting of the first elastic member 61 include the conditions of the joined members such as the material of the members to be joined and the shape of the joined part, and the joining modes such as the insertion depth of the stirring pin 60, the shape of the rotating tool, the rotation speed, and the moving speed.

[0044] <First restricting member> The first restricting member (first loose-fitting restricting member) 100 is a member that restricts the movement of the stirring pin 60 beyond a predetermined range toward the proximal end side of the rotation axis 12, as shown in FIG. 1 and the like. In the present embodiment, the first restricting member 100 is disposed in a loose-fitting state in the hollow portion of the first elastic member 61 inside the first holder 21. The first restricting member 100 is formed of a relatively hard material such as metal, resin, rubber, etc., so as to withstand the reaction force during friction stir joining. In the present embodiment, the first restricting member 100 has a columnar shape, but may be appropriately formed according to the shape of the placement location. The first restricting member 100 restricts the movement of the stirring pin 60 so that the amount of deformation generated in the first elastic member 61 as the stirring pin 60 moves does not exceed the maximum deflection amount (maximum allowable amount) of the first elastic member 61.

[0045] For example, the maximum deflection amount of the first elastic member 61 according to the present embodiment is set when the first elastic member 61 is deformed by 30% with respect to its free length. The maximum deflection amount means the amount by which the first elastic member 61 is most compressed when the elastic force thereof is exerted. If the maximum deflection amount is exceeded, the elastic force of the first elastic member 61 may not be exerted as designed, or the first elastic member 61 may be damaged earlier than expected.

[0046] As shown in FIG. 4, in this embodiment, when the amount of deflection of the first elastic member 61 is 30% with respect to the free length of the first elastic member 61, the tip portion (tip surface) 100a of the first regulating member 100 abuts against the base end portion 31b of the first slide shaft 31, and the base end portion (base surface) 100b abuts against the bottom portion 22a of the first storage recess 22. Thereby, it is possible to prevent the first elastic member 61 from deforming beyond the maximum amount of deflection. The maximum amount of deflection of the first elastic member 61 can be appropriately set according to the first elastic member 61 and the first regulating member 100. The maximum amount of deflection of the first elastic member 61 may be, for example, 25%, 20%, 15%, 10%, or 5%.

[0047] In this embodiment, since the first elastic member 61 is used, the term "maximum amount of deflection" is used. Also, as described above, for example, when another member (a fluid spring using pneumatic pressure, gas pressure, or hydraulic pressure, or a magnetic spring using magnetic force or electromagnetic force) is used as the first elastic member, if the amount exceeds that, the elastic force may not be generated or the elastic member may be damaged, and the amount is defined as the "maximum allowable capacity".

[0048] Further, in this embodiment, the first regulating member 100 is a solid such as metal, and regulates the movement of the stirring pin 60 by contact. However, for example, a fluid spring using pneumatic pressure, gas pressure, or hydraulic pressure, or a magnetic spring using magnetic force or electromagnetic force may regulate the movement of the stirring pin 60 non - contact.

[0049] Also, as long as the first regulating member 100 regulates the movement of the stirring pin 60, its shape and arrangement are not limited. For example, the first regulating member 100 may be such that a part of the main body portion 10 or the stirring pin 60 functions as the first regulating member 100, or the first regulating member 100 may be provided by being integrally formed with the main body portion 10 or the stirring pin 60, or the first regulating member 100 may be provided in a form in which a separate member is attached to the main body portion 10 or the stirring pin 60.

[0050] <Shoulder> The shoulder 70 is a part that presses the joined member in a state of contacting the joined member. The shoulder 70 is configured separately from the stirring pin 60 and is connected to the main body 10 so as to be movable in the axial direction of the rotation axis individually from the stirring pin 60. The shoulder 70 is formed of, for example, tool steel. The shoulder 70 has a cylindrical shape and is coaxially arranged so as to surround the stirring pin 60. That is, the stirring pin 60 is inserted into the hollow portion 72 of the shoulder 70. The stirring pin 60 is relatively rotatable with respect to the shoulder 70 and is relatively movable in the axial direction. The tip end portion 73 of the shoulder 70 is at the same height as the base end portion of the tapered surface of the tip end portion 62 of the stirring pin 60. That is, the tip end portion 62 of the stirring pin 60 protrudes toward the tip end side from the tip end portion 73 of the shoulder 70. In other words, the stirring pin 60 protrudes below the tip end portion 73 of the shoulder 70. The shoulder 70 is integrally formed with the second slide shaft 51 and moves in the axial direction of the rotation axis by the slide movement of the second slide shaft 51. The second slide shaft 51 is connected to the base end portion 74 of the shoulder 70 and protrudes toward the second storage recess 42. The second slide shaft 51 is connected to the base end portion 74 of the shoulder 70 at four locations with a 90° pitch (see FIG. 3). Note that the number of the second slide shafts 51 is not limited to four, and may be 1, or may be 2, 3, or 5 or more as long as the number corresponds to the second storage recess 42.

[0051] As described above, since the second slide shaft 51 integrally formed with the shoulder 70 is inserted into the second storage recess 42 of the second holder 41, the shoulder 70 rotates synchronously with the second holder 41 to do.

[0052] <Second elastic member> The second elastic member 71 is a part that biases the shoulder 70 toward the distal end side with respect to the axial direction of the rotation shaft 12. The second elastic member 71 is configured by, for example, a coil spring similar to the first elastic member 61. The second elastic member 71 is mounted between the proximal end portion 51b of the second slide shaft 51 and the bottom portion 42a of the second storage recess 42. The second elastic member 71 is capable of biasing the shoulder 70 toward the distal end side against the force received from the shoulder 70.

[0053] The elasticity of the second elastic member 71 is such that when the stirring pin 60 is inserted into the joined member 2 made of at least one material selected from the group consisting of aluminum, copper, magnesium, and alloys thereof with a predetermined pushing load, the shoulder 70 is displaced within a predetermined range within the entire movable range of the shoulder 70 by the second elastic member 71 so as to press the joined member 2.

[0054] For example, when the second elastic member 71 is a coil spring and the load applied to the second elastic member 71 is inserted at 50 kg to 2 t, the shoulder 70 is set to press the joined member 2 in a state where the amount of deflection of the second elastic member 71 is deformed in the range of 0 to 30% with respect to the free length of the second elastic member 71. Thereby, in a state where the shoulder 70 is in contact with the joined member 2, the shoulder 70 does not need to be inserted into the joined member 2, and it becomes easier to hold down the joined member with the shoulder 70. The second elastic member 71 is more easily deformed than the first elastic member 61.

[0055] Note that the second elastic member 71 is not limited to a coil spring like the first elastic member 61, and may be a metal spring such as a leaf spring or a disc spring, or a polymer elastic body (elastomer) such as rubber, a polymer resin, or a sponge-like resin. Further, the second elastic member 71 may be a fluid spring using pneumatic pressure, gas pressure, or hydraulic pressure, or a magnetic spring using magnetic force or electromagnetic force.

[0056] The second elastic member 71 may be set so as to satisfy the relationship between the deformation amount and the elastic modulus such that the shoulder 70 pressed against the joined member 2 can hold down the joined member 2 without being inserted into the joined member 2 while being in contact with the joined member 2, taking into account the joining conditions. Examples of the joining conditions that affect the setting of the second elastic member 71 include conditions of the joined member such as the material of the joined member 2 and the shape of the joining part, and joining modes such as the insertion depth of the stirring pin 60, the shape of the rotary tool 1, the rotation speed, and the moving speed. It is sufficient that at least a part of the shoulder 70 is in contact with the joined member 2, and a slight space may be formed between the shoulder 70 and the joined member 2 according to the surface shape of the joined member 2, but it is preferable that the shoulder 70 is in contact with the joined member 2 without a gap so as to hold down the metal material overflowed by friction stir welding and prevent the generation of burrs. Further, the shoulder 70 may be slightly inserted into the joined member 2, but it is preferable that the shoulder 70 is not deeply inserted into the joined member 2 to such an extent that a recess is not formed due to the contact between the joined member 2 and the shoulder 70 after joining.

[0057] <Second restricting member> As shown in FIG. 1 and the like, the second restricting member (second loose fitting restricting member) 110 is a member that restricts the shoulder 70 from moving toward the proximal end side of the rotary shaft 12 beyond a predetermined range. In the present embodiment, the second restricting member 110 is disposed in a loose fitting state in the hollow portion of the second elastic member 71. A total of four second restricting members 110 are disposed together with the second elastic member 71. The second restricting member 110 is formed of a relatively hard material such as metal, resin, rubber, etc. so as to withstand the reaction force during friction stir welding. In the present embodiment, the second restricting member 110 has a columnar shape, but it may be appropriately formed according to the shape of the placement location. The second restricting member 110 restricts the movement of the shoulder 70 so that the deformation amount generated in the second elastic member 71 due to the movement of the shoulder 70 does not exceed the maximum deflection amount (maximum allowable amount) of the second elastic member 71.

[0058] As shown in FIG. 4, in the present embodiment, when the amount of deflection of the second elastic member 71 becomes 30% with respect to the free length of the second elastic member 71, the tip portion (tip surface) 110a of the second restricting member 110 abuts against the base end portion 51b of the second slide shaft 51, and the base end portion (base surface) 110b abuts against the bottom portion 42a of the second storage recess 42. Thereby, it is possible to prevent the second elastic member 71 from deforming beyond the maximum amount of deflection. The maximum amount of deflection of the second elastic member 71 can be appropriately set according to the second elastic member 71 and the second elastic member 71. The maximum amount of deflection of the second elastic member 71 may be, for example, 25%, 20%, 15%, 10%, or 5%.

[0059] In the present embodiment, since the second elastic member 71 is used, the "maximum amount of deflection" is used. Further, in the present embodiment, the second restricting member 110 is a solid such as metal, and the movement of the shoulder 70 is restricted by contact. However, for example, a fluid spring using pneumatic pressure, gas pressure, or hydraulic pressure, or a magnetic spring using magnetic force or electromagnetic force may be used to restrict the movement of the shoulder 70 non - contact.

[0060] Further, as long as the second restricting member 110 restricts the movement of the shoulder 70, its shape and arrangement are not limited. For example, the second restricting member 110 may be such that a part of the main body portion 10 or the shoulder 70 functions as the second restricting member 110, the second restricting member 110 may be provided by being integrally formed with the main body portion 10 or the shoulder 70, or the second restricting member 110 may be provided in a form in which a separate member is attached to the main body portion 10 or the shoulder 70.

[0061] <Retention part> As shown in FIG. 1, the holding part 80 is a rod-shaped arm member, and its tip is fixed to the outer peripheral surface of the second holder 41. The base end of the holding part 80 is connected to the fixing system of the joining device 3 and is configured to hold the second holder 41 in a non-rotating state. This holding part 80 is included in the rotary tool 1. The second holder 41 and the shoulder 70 are provided so as to be relatively rotatable with respect to the rotary shaft 12 and the first holder 21 and the stirring pin 60, and are further held in a non-rotating state by the holding part 80. Thereby, even when the stirring pin 60 rotates, the shoulder 70 can be held in a non-rotating state.

[0062] [1-2. Joining Device] Next, the configuration of the joining device 3 provided with the rotary tool 1 having the above configuration will be described. Such a joining device 3 includes power means (not shown) for outputting a rotational force transmitted to the rotary shaft 12 of the rotary tool 1, and position control means (not shown) for holding the fixing part 11 of the rotary tool 1 and performing position control of the rotary tool. The joining device 3 is configured, for example, by a machining center that performs position control. The position control device is configured by a CPU or the like, and operates the power means to move the rotary tool 1 based on the position information input in advance. The power means moves the rotary tool 1 in the three axial directions of X, Y, and Z.

[0063] [1-3. Joining Method] Next, the joining method according to the present invention will be described with reference to FIGS. 5 and 6. In such a joining method, the rotary tool 1 of the present embodiment is moved to a predetermined height position preset with respect to the joined member 2, and while pressing the shoulder 70 of the rotary tool 1 against the joined member 2, the stirring pin 60 of the rotary tool 1 that rotates with respect to the joined member 2 is inserted to perform friction stir joining on the joined member 2.

[0064] When inserting the stirring pin 60, as shown in FIGS. 5(a) and 5(b), as the rotary tool 1 is brought closer to the joined member 2 in the insertion direction, first, the tip of the stirring pin 60 contacts the joined member 2. When the rotary tool 1 is further brought closer to the joined member 2, the first elastic member 61 is compressed, and the elastic force of the first elastic member 61 that biases the stirring pin 60 toward the joined member 2 increases, and the stirring pin 60 is inserted into the joined member 2. In this way, until the stirring pin 60 is inserted into the joined member 2 at a desired depth, the rotary tool 1 is brought closer to the joined member 2 in the insertion direction for joining. At this time, the first elastic member 61 and the joining conditions are set so that the stirring pin 60 can be inserted into the joined member 2 while leaving a margin due to the deformation of the first elastic member 61 so that the deflection amount of the first elastic member 61 does not exceed the maximum deflection amount. Alternatively, with the movement of the stirring pin 60 restricted by the first restricting member 100 so that the deflection amount of the first elastic member 61 does not exceed the maximum deflection amount, the stirring pin 60 is pressed against the joined member 2, and the stirring pin 60 is inserted into the joined member 2.

[0065] As shown in FIG. 5(c), when the rotary tool 1 is further brought closer to the joined member 2, the shoulder 70 contacts the joined member 2. The second elastic member 71 is compressed, and the elastic force of the second elastic member 71 that biases the shoulder 70 toward the joined member 2 increases, and the shoulder 70 is pressed against the joined member 2. At this time, the elastic force of the second elastic member 71 is set so that the shoulder 70 can be pressed against the joined member 2 while leaving a margin due to the deformation of the second elastic member 71 without the second elastic member 71 being completely deformed. Also, the second elastic member 71 is set so that the shoulder 70 can hold down the joined member 2 without being inserted into the joined member 2 in a state of being in contact with the joined member 2.

[0066] During joining with the rotary tool 1, as shown on the left side in FIG. 6, the stirring pin 60 is biased toward the tip side by the first elastic member 61, and the shoulder 70 is biased toward the tip side by the second elastic member 71. Thus, when there is no error in the height of the workpiece 2 with respect to the set value, as shown on the left side in FIG. 6, the tip portion 62 of the stirring pin 60 is inserted into the workpiece 2 at a desired depth. Further, the shoulder 70 is capable of pressing the workpiece 2 in a state of being in contact with the workpiece without being inserted into the workpiece 2.

[0067] Next, as shown in the central portion of FIG. 6, a case where the height of the workpiece 2 becomes slightly higher than the set value due to an error during friction stir joining will be described. Here, if the stirring pin 60 is directly pushed into the workpiece 2 without the first elastic member 61, the insertion amount of the stirring pin 60 increases by the amount by which the height of the workpiece 2 has increased as compared with the case where there is no error in the height of the workpiece 2 with respect to the set value. On the other hand, when joining is performed with the rotary tool 1 of the present embodiment, the stirring pin 60 receives an upward reaction force from the workpiece 2 due to the increase in the height of the workpiece 2 and is pushed upward, and by this upward push, the first elastic member 61 is compressed, and the stirring pin 60 receives a downward elastic force from the first elastic member 61 and is pushed downward. The position of the stirring pin 60 is changed to a position where the upward reaction force and the downward elastic force balance with each other as the height of the workpiece 2 changes. The first elastic member 61 is set so that the insertion amount of the stirring pin 60 at this time is approximately the same as the insertion amount when there is no error in the height of the workpiece 2 with respect to the set value. If the elastic force of the first elastic member 61 is too weak, the upward reaction force accompanying the change in the height of the workpiece 2 becomes larger, and the insertion amount becomes smaller. On the other hand, if the elastic force of the first elastic member 61 is too strong, the downward elastic force accompanying the change in the height of the workpiece 2 becomes larger, and the insertion amount becomes larger. That is, even when the height of the workpiece 2 fluctuates and increases, in the rotary tool 1, the first elastic member 61 is set so that the stirring pin 60 is inserted into the workpiece 2 at a desired depth set according to the set height of the workpiece 2.

[0068] Also, here, if the shoulder 70 was directly pushed into the joined member 2 without the second elastic member 71, the insertion amount of the shoulder 70 would increase by the amount that the height of the joined member 2 became higher compared to the case where there was no error in the height of the joined member 2 with respect to the set value. In contrast, when joining is performed by the rotary tool 1 of the present embodiment, when the height of the joined member 2 increases, the shoulder 7 is pushed upward by receiving an upward reaction force from the joined member 2, and by this upward push, the second elastic member 71 is compressed, and the shoulder 70 is pushed downward by receiving a downward elastic force from the second elastic member 71. In this way, the position of the shoulder 70 is changed to a position where the upward reaction force and the downward elastic force balance with the change in the height of the joined member 2. The second elastic member 71 is set so that the shoulder 70 at this time is pressed in the same manner as when there is no error in the height of the joined member 2 with respect to the set value. If the elastic force of the second elastic member 71 is too weak, the upward reaction force accompanying the change in the insertion depth becomes larger, and the pressing becomes insufficient, so that the shoulder 70 cannot suppress the generation of burrs. Also, if the elastic force of the second elastic member 71 is too weak, the upward reaction force accompanying the change in the height of the joined member 2 becomes larger, and the pressing becomes insufficient, resulting in defects in the joined portion. On the other hand, if the elastic force of the second elastic member 71 is too strong, the downward elastic force accompanying the change in the height of the joined member 2 becomes larger, and the insertion force becomes larger, so that the shoulder 70 is inserted into the joined member 2. That is, in the rotary tool 1, even when the height of the joined member 2 fluctuates, the second elastic member 71 is set so that the shoulder 70 presses the joined member 2 without being inserted into the joined member 2 while being in contact with the joined member 2.

[0069] Furthermore, when the height of the member 2 to be joined becomes lower than the set value, as shown on the right side in FIG. 6, the first elastic member 61 extends, the stirring pin 60 descends, the second elastic member 71 extends, and the shoulder 70 descends. In this way, even when the height of the member 2 to be joined fluctuates and becomes lower, in the rotary tool 1, the first elastic member 61 is set so that the stirring pin 60 is inserted into the member 2 to be joined at a desired depth set according to the set height of the member 2 to be joined. Also, even when the height of the member 2 to be joined fluctuates and becomes lower, in the rotary tool 1, the second elastic member 71 is set so that the shoulder 70 presses the member 2 to be joined without being inserted into the member 2 while being in contact with the member 2 to be joined.

[0070] Thereafter, at the pulling-out position of the stirring pin, as the rotary tool 1 is moved away from the member 2 to be joined, first, the shoulder 70 detaches from the member 2 to be joined. When the rotary tool 1 is further moved away from the member 2 to be joined, the insertion amount of the stirring pin 60 gradually becomes smaller. Then, when the rotary tool 1 is moved further away from the member 2 to be joined, the stirring pin 60 detaches from the member 2 to be joined.

[0071] As described above, in the rotary tool 1, due to the action of the first elastic member 61, the stirring pin 60 is inserted into the member 2 to be joined at a constant depth, so that a plasticized region is formed at a constant depth. Therefore, stable joining quality can be obtained. Also, in the rotary tool 1, due to the action of the second elastic member 71, while maintaining the state where the shoulder 70 presses the member 2 to be joined, the stirring pin 60 is inserted into the member 2 to be joined to perform friction stirring, so that the shoulder 70 can press the metal material overflowing from the insertion site of the stirring pin 60 due to the friction stirring by the stirring pin 60. Therefore, the generation of burrs can be reduced.

[0072] [1-4. Action and Effect] According to the rotary tool 1, the joining device 3, and the joining method according to this embodiment, since the stirring pin 60 provided so as to be movable in the axial direction of the rotary shaft 12 is biased toward the tip side by the first elastic member 61, when the tip portion 62 of the stirring pin 60 is inserted into the member to be joined 2, the stirring pin 60 is inserted to a predetermined depth according to the elasticity of the first elastic member 61. By setting the first elastic member 61 in consideration of joining conditions such as the joining member and the joining mode, the stirring pin 60 can be inserted to a desired depth. That is, the rotary tool 1 can perform pseudo load control using the first elastic member 61.

[0073] When a rotary tool without an elastic member is attached to a joining device such as a machining center that can only perform position control, the support height of the rotary tool 1 becomes constant based on the set value by the machining center, and the insertion position of the stirring pin 60 becomes substantially constant. On the other hand, when the rotary tool 1 of this embodiment is used, even if the support height of the rotary tool 1 by the machining center is constant, the first elastic member 61 expands and contracts appropriately according to the height of the member to be joined 2, and the stirring pin 60 moves in the axial direction. Thus, by utilizing the elasticity of the first elastic member 61, load control is possible in which the insertion depth of the stirring pin 60 into the member to be joined 2 can be controlled.

[0074] Further, the rotary tool 1 is provided with a shoulder 70 that is disposed so as to be movable separately from the stirring pin 60 in the axial direction of the rotary shaft 12 without receiving the rotational force from the main body portion (rotary shaft 12) and presses the member to be joined 2. By the shoulder 70 pressing down on the metal material that has overflowed from the insertion site of the stirring pin 60 due to friction stirring by the stirring pin 60, the generation of burrs can be reduced. In this way, the finish of the surface after friction stir joining is improved by the shoulder 70.

[0075] Furthermore, the rotary tool 1 is provided with a second elastic member 71 that biases the shoulder 70 toward the tip side. As a result, the shoulder 70 can also be load-controlled by the second elastic member 71, so that the finish of the surface after friction stir joining becomes even better.

[0076] Here, regarding load control, when performing friction stir welding using, for example, a compression coil spring as the elastic member, the stirring pin could be inserted into the relatively soft aluminum alloy of the 1000 series, but there was a case where the stirring pin could not be inserted into the hard aluminum alloy.

[0077] This is because it is necessary to avoid compressing the compression coil spring beyond its maximum allowable capacity (maximum deflection amount). In other words, it is difficult to apply a load to the rotating tool to such an extent that the maximum deflection amount of the compression coil spring is exceeded. That is, it is difficult to insert the stirring pin while performing simple load control for a hard workpiece that requires compression beyond the limit of the compression coil spring. If the maximum deflection amount of the compression coil spring is exceeded, the spring may be damaged prematurely.

[0078] By the way, for example, when bringing the stirring pin 60 into contact with the workpiece 2 and proceeding with the insertion while increasing the load applied to the rotating tool 1, such as at the start position of friction stir welding, as time passes and the insertion amount increases, the generated reaction force (generated reaction) and heat generation due to frictional heat increase. Usually, in friction stir welding, the softening of the material due to the heat generation of the stirring pin 60 cannot catch up with the insertion of the stirring pin 60, and the generated reaction force is highest when the stirring pin 60 is pushed to a predetermined depth. When the stirring pin 60 is inserted into the workpiece 2 to the predetermined depth and the pushing of the rotating tool 1 stops, the softening of the material due to the heat generation of the stirring pin 60 catches up with the insertion amount of the rotating tool 1, and the load applied to the rotating tool 1 can be reduced, and the generated reaction force can be decreased. Such a state is called the "steady state".

[0079] FIG. 7 is a graph showing the time and the generated reaction force during friction stir welding of the rotary tool according to the first embodiment. Point P1 indicates the position where the stirring pin 60 is pushed into the workpiece 2 most at the start position of friction stir welding. Point P2 indicates the start position of the steady state of friction stir welding. Until reaching point P1, it is a rising straight line on the right, indicating a state where the stirring pin 60 is being pushed into the workpiece 2. During friction stir welding, when the stirring pin 60 is pushed in, the generated reaction force gradually increases and heads towards the peak (point P1). After the generated reaction force slightly decreases according to the progress of the stirring pin 60, it enters the steady state (point P2) and the generated reaction force becomes generally constant.

[0080] The rotary tool 1 according to the present embodiment includes a first regulating member 100 that regulates the movement of the stirring pin 60 toward the proximal end side in the axial direction, and a second regulating member 110 that regulates the movement of the shoulder 70 toward the proximal end side in the axial direction. Thereby, when the rotary tool 1 is inserted where the generated reaction force (load) is maximum, or at a position where the shape of the workpiece 2 changes greatly, the amount of deformation generated in the first elastic member 61 and the second elastic member 71 does not exceed the maximum deflection amount of the first elastic member 61 and the second elastic member 71, and the movement of the stirring pin 60 and the shoulder 70 is regulated by the first regulating member 100 and the second regulating member 110. Therefore, even when the workpiece 2 is relatively hard and requires a large load, it is possible to avoid the first elastic member 61 and the second elastic member 71 from deforming beyond the limit. Thereby, even for a relatively hard workpiece 2, the stirring pin 60 can be inserted while utilizing the first elastic member 61 and the second elastic member 71, and damage to the first elastic member 61, the second elastic member 71, and the rotary tool 1 can be prevented.

[0081] Also, in a state where the stirring pin 60 regulated by the first regulating member 100 is supported by the first regulating member 100 (a state where the first regulating member 100 is in contact with and clamped between the first slide shaft 31 and the bottom portion 22a), the stirring pin 60 is pressed against the workpiece 2, and the load applied by the joining device is applied to the stirring pin 60 via the first regulating member 100, so that the stirring pin 60 can be inserted into the workpiece 2.

[0082] Further, in a state where the shoulder 70 regulated by the second regulating member 110 is supported by the second regulating member 110 (a state where the second regulating member 110 is in contact with and clamped by the second slide shaft 51 and the bottom portion 42a), the shoulder 70 can be pressed against the joined member 2. That is, by the cooperation of the first regulating member 100 and the second regulating member 110, the stirring pin 60 can be inserted into the relatively hard joined member 2, and the joined member 2 can be held down to suppress the generation of burrs.

[0083] Thereafter, in the steady state, the generated reaction force (load) is reduced, the support of the stirring pin 60 by the first regulating member 100 is released, and the stirring pin 60 that is no longer regulated by the first regulating member 100 can move in the axial direction of the rotating shaft 12. Similarly, the support of the shoulder 70 by the second regulating member 110 is released, and the shoulder 70 that is no longer regulated by the second regulating member 110 can move in the axial direction of the rotating shaft 12.

[0084] In addition, in order to prevent the rotation tool 1 from becoming large, it is preferable that the outer diameters and free lengths of the first elastic member 61 and the second elastic member 71 are as small (short) as possible. With a constant outer diameter, the shorter the free lengths of the first elastic member 61 and the second elastic member 71, the greater the spring constant tends to be, so it becomes easier to insert into the relatively hard joined member 2. However, when the spring constant is increased, the generated reaction force (load) with respect to the change amount becomes large, so the robustness decreases. That is, when the spring constant is increased, the stirring pin 60 and the shoulder 70 are easily affected by the first elastic member 61 and the second elastic member 71, so there is a problem that the operations of the stirring pin 60 and the shoulder 70 are not stable (difficult to control) in the steady state.

[0085] In this regard, according to the present embodiment, even if the spring constants of the first elastic member 61 and the second elastic member 71 are not increased, the first restricting member 100 restricts the movement of the first slide shaft 31, and the second restricting member 110 restricts the movement of the second slide shaft 51. Therefore, forces can be transmitted to the stirring pin 60 and the shoulder 70 via the first restricting member 100 and the second restricting member 110, respectively. As a result, the stirring pin 60 can be inserted into the relatively hard joined member 2, and can be pressed by the shoulder 70. In addition, since the first elastic member 61 and the second elastic member 71 do not need to have increased spring constants due to the provision of the first restricting member 100 and the second restricting member 110, the degree of freedom in the design of each elastic member is increased, and the robustness in the steady state can be enhanced, and the stirring pin 60 and the shoulder 70 can be stably controlled.

[0086] The main body portion 10 further includes a cylindrical first holder 21 and a first slide shaft 31 that is slidably accommodated in the central portion of the first holder 21 in the rotational axis direction and rotates synchronously with the first holder 21. The stirring pin 60 is provided at the tip of the first slide shaft 31. Thereby, while transmitting the rotational force from the main body portion 10 to the stirring pin 60, the stirring pin 60 can slide in the rotational axis direction.

[0087] In the rotary tool 1, the first elastic member 61 is accommodated inside the first holder 21 and is disposed between the base end portion of the first slide shaft 31 and the fixed portion side of the first holder 21. As a result, the first elastic member 61 is positioned near the intermediate portion between the first slide shaft 31 and the stirring pin 60, and the force received by the first elastic member 61 from the stirring pin 60 side can be received by the bottom portion 22a of the first holder 21. Therefore, even if the first slide shaft 31 moves, since the first elastic member 61 stably biases the stirring pin 60 toward the tip side, the accuracy of load control of the stirring pin 60 can be improved.

[0088] In addition, a key groove 23 is formed in the first holder 21, and a key 32 is formed on the first slide shaft 31. As a result, the first slide shaft 31 and the stirring pin 60 rotate synchronously as the rotary shaft 12 and the first holder 21 rotate, while allowing movement in the axial direction in a stable state. Therefore, the operation of the stirring pin 60 becomes even more stable.

[0089] Furthermore, the main body portion 10 has a second holder 41 and a second slide shaft 51. The shoulder 70 can rotate relative to the first holder 21 and the rotary shaft 12, and can slide stably in the axial direction of the rotary shaft 12 in a non-rotating state.

[0090] The shoulder 70 has a cylindrical shape, the stirring pin 60 passes through the hollow portion 72 of the shoulder 70, and the tip portion 62 of the stirring pin 60 protrudes below the tip portion (tip surface) 73 of the shoulder 70. Therefore, the stirring pin 60 can rotate stably inside the shoulder 70, and the tip portion 73 of the shoulder 70 can press the periphery of the friction stir zone.

[0091] Since the rotary tool 1 includes a holding portion 80 that holds the shoulder 70 in a non-rotating state, it becomes easier to hold the shoulder 70 in a non-rotating state, and the finish of the surface of the joined member 2 after friction stir joining becomes even better.

[0092] In the rotary tool 1, the first elastic member 61 is preferably an elastic member that imparts an elastic force by at least one selected from a solid spring, a fluid spring, a magnetic force, and an electromagnetic force. According to such a configuration, it is easy to adjust the elasticity of the first elastic member 61.

[0093] The joining device 3 includes a rotary tool 1, a power means, and a position control means. The position control means moves the rotary tool 1 to a predetermined height position with respect to the workpiece 2, and while pressing the shoulder 70 of the rotary tool 1 against the workpiece 2, inserts the stirring pin 60 of the rotary tool 1 into the workpiece 2 to perform friction stir joining on the workpiece 2. According to this joining device 3, by utilizing the elasticity of the first elastic member 61, it is possible to perform friction stir joining while performing load control for controlling the insertion depth of the stirring pin 60 into the workpiece 2. Further, the shoulder 70 presses the metal material that has overflowed from the insertion site of the stirring pin 60 due to the friction stirring by the stirring pin 60, thereby reducing the generation of burrs and improving the surface finish after friction stir joining.

[0094] In this joining method, the rotary tool 1 is moved to a predetermined height position with respect to the workpiece 2, and while pressing the shoulder 70 against the workpiece 2, the rotating stirring pin 60 is inserted into the workpiece 2 to perform friction stir joining on the workpiece 2. According to this joining method, by utilizing the elasticity of the first elastic member 61, it is possible to perform friction stir joining while performing load control for controlling the insertion depth of the stirring pin 60 into the workpiece 2. Further, the shoulder 70 presses the metal material that has overflowed from the insertion site of the stirring pin 60 due to the friction stirring by the stirring pin 60, thereby reducing the generation of burrs and improving the surface finish after friction stir joining.

[0095] As described above, according to the rotary tool 1, the joining device 3, and the joining method, even when mounted on a machining center that only performs position control, it is possible to perform friction stir joining while performing load control by utilizing the first elastic member 61. Further, according to the rotary tool 1, the joining device 3, and the joining method, by utilizing the first regulating member 100, it is possible to prevent damage to the first elastic member 61 and insert the stirring pin even for a relatively hard workpiece, and perform friction stir joining while performing load control.

[0096] [2. Modification Example] Next, with reference to FIG. 8, a modified example of the holding portion will be described. As the holding portion 85 according to the modified example, as shown in FIG. 8, a rectangular portion 48 having a rectangular outer shape may be provided at the lower end portion of the second holder 41a, and a guide member 86 may be provided along the movement locus of the rotary tool 1a. The guide member 86 is formed of a long member and is disposed on both sides with a space of substantially the same length as the width of the rectangular portion 48 so as to sandwich the rectangular portion 48 of the second holder 41a from both sides. The guide member 86 is a holding portion provided in the joining device 3. The second holder 41a having such a configuration moves along the movement locus without rotating while the outer peripheral surface of the rectangular portion 48 slides on the side surface of the guide member 86. Inside the second holder 41a, a stirring pin 60, a first holder 21, and a bearing are inserted in the same manner as the second holder 41 in FIG. 1. Since other configurations are the same as those of the rotary tool 1 in FIG. 1, the same reference numerals are given and the description thereof is omitted.

[0097] [3. Second Embodiment] Next, with reference to FIG. 9, the rotary tool 1A according to the second embodiment will be described. As shown in FIG. 9, the rotary tool 1A according to the second embodiment includes a main body portion 10 having a first holder 21, a first slide shaft 31, a second holder 41, and a second slide shaft 51, a stirring pin 60, a first elastic member 61, a shoulder 70, a second elastic member 71, a first regulating member 100A, and a second regulating member 110A. Since the basic configuration is the same as that of the first embodiment, the same reference numerals are given and the description thereof is omitted.

[0098] The first regulating member (first proximal end side fixing regulating member) 100A according to the present embodiment is fixedly provided at the bottom portion 22a of the first storage recess 22. That is, the proximal end portion 100Ab of the first regulating member 100A and the bottom portion 22a are always connected. Further, the second regulating member (second proximal end side fixing regulating member) 110A is fixed to the bottom portion 42a of the second storage recess 42. That is, the proximal end portion 110Ab of the second regulating member 110A and the bottom portion 42a are always connected.

[0099] Although specific illustrations are omitted, as shown in FIG. 4, until the first elastic member 61 and the second elastic member 71 reach the maximum deflection amount, the tip 100Aa of the first restricting member 100A abuts against the base end portion 31b of the first slide shaft 31, and the movement of the first slide shaft 31 and the base end side of the stirring pin 60 can be restricted. Further, the tip 110Aa of the second restricting member 110A abuts against the base end portion 51b of the second slide shaft 51, and the movement of the second slide shaft 51 and the base end side of the shoulder 70 can be restricted.

[0100] Also according to the present embodiment, effects substantially equivalent to those of the first embodiment can be achieved. Further, according to the present embodiment, since the first restricting member 100A is provided at the bottom portion 22a of the first holder 21, it is possible to prevent the restricting member from contacting the first elastic member 61 by the restricting member floating inside the first holder 21. Similarly, since the second restricting member 110A is provided at the bottom portion 42a of the second holder 41, it is possible to prevent the restricting member from contacting the second elastic member 71 by the restricting member floating inside the second holder 41. Further, since the first restricting member 100A can be fixed in a fixed position, the tip 100Aa of the first restricting member 100A and the base end portion 31b of the first slide shaft 31 can be brought into contact at a fixed position, and the reaction force generated with the insertion of the rotary tool 1A can be received at a predetermined position to perform a stable operation.

[0101] [4. Third Embodiment] Next, with reference to FIG. 10, the rotary tool 1B according to the third embodiment will be described. As shown in FIG. 10, the rotary tool 1B according to the third embodiment includes a main body portion 10 having a first holder 21, a first slide shaft 31, a second holder 41, and a second slide shaft 51, a stirring pin 60, a first elastic member 61, a shoulder 70, a second elastic member 71, a first restricting member 100B, and a second restricting member 110B. Since the basic configuration is the same as that of the first embodiment, the same reference numerals are given and the description thereof is omitted.

[0102] The first regulating member (first tip-side fixing regulating member) 100B according to the present embodiment is provided fixed to the base end portion 31b of the first slide shaft 31. That is, the tip end portion 100Ba of the first regulating member 100B and the base end portion 31b of the first slide shaft 31 are always connected. Further, the second regulating member (second tip-side fixing regulating member) 110B is provided fixed to the base end portion 51b of the second slide shaft 51. That is, the tip end portion 110Ba of the second regulating member 110B and the base end portion 51b of the second slide shaft 51 are always connected.

[0103] Although specific illustration is omitted, as shown in FIG. 4, until the first elastic member 61 and the second elastic member 71 reach the maximum deflection amount, the base end portion 100Bb of the first regulating member 100B and the bottom portion 22a of the first storage recess 22 come into contact with each other, and the movement of the first slide shaft 31 and the base end side of the stirring pin 60 can be restricted. Further, the base end portion 110Bb of the second regulating member 110B and the bottom portion 42a of the second storage recess 42 come into contact with each other, and the movement of the second slide shaft 51 and the base end side of the shoulder 70 can be restricted.

[0104] Also according to the present embodiment, substantially the same effects as those of the first embodiment can be achieved. Further, according to the present embodiment, since the first regulating member 100B is provided on the first slide shaft 31, it is possible to avoid the regulating member coming into contact with the first elastic member 61 by the regulating member floating inside the first holder 21. Similarly, since the second regulating member 110B is provided on the second slide shaft 51, it is possible to avoid the regulating member coming into contact with the second elastic member 71 by the regulating member floating inside the second holder 41. Further, since the first regulating member 100B can be fixed at a fixed position, the base end portion 100Bb of the first regulating member 100B and the bottom portion 22a of the first holder 21 can be brought into contact with each other at a fixed position, and the reaction force generated with the insertion of the rotary tool 1B can be received at a predetermined position to perform a stable operation.

[0105] [5. Fourth Embodiment] Next, with reference to FIGS. 11 and 12, the rotary tool 1C according to the fourth embodiment will be described. The rotary tool 1C according to the fourth embodiment includes a main body 10 having a first holder 21, a first slide shaft 31, a second holder 41, and a second slide shaft 51, a stirring pin 60, a first elastic member 61, a shoulder 70, a second elastic member 71, a first regulating member 100C, and a second regulating member 110C. Since the basic configuration is the same as that of the first embodiment, the same reference numerals are given and the description thereof is omitted.

[0106] The first regulating member (first intermediate regulating member) 100C according to the present embodiment is fixedly provided on the outer peripheral surface (side surface portion) of the first slide shaft 31. The first regulating member 100C is a plate-like member that projects radially outward in a direction perpendicular to the outer peripheral surface of the first slide shaft 31. The first regulating member 100C may be single or a plurality may be formed. The first regulating member 100C is formed so as to move axially within a through hole M that penetrates radially outward of the first holder 21 as the first slide shaft 31 moves. As shown in FIG. 12, until the first elastic member 61 reaches the maximum deflection amount, the first regulating member 100C abuts against the hole wall (intermediate portion of the first holder) Ma on the proximal end side of the through hole M, and the movement of the proximal end side of the first slide shaft 31 and the stirring pin 60 can be restricted.

[0107] The second regulating member (second intermediate regulating member) 110C is fixed to the outer peripheral surface of the second slide shaft 51. The second regulating member 110C is a plate-like member that projects radially outward in a direction perpendicular to the outer peripheral surface of the second slide shaft 51. The second regulating member 110C may be single or a plurality may be formed. The second regulating member 110C is formed so as to move axially within a through hole N that penetrates radially outward of the second holder 41 as the second slide shaft 51 moves. As shown in FIG. 12, until the second elastic member 71 reaches the maximum deflection amount, the second regulating member 110C abuts against the hole wall (intermediate portion of the second holder) Na on the proximal end side of the through hole N, and the movement of the proximal end side of the second slide shaft 51 and the shoulder 70 can be restricted.

[0108] In this embodiment, the through hole M of the first holder 21 is regarded as the "intermediate portion". However, other portions of the first holder 21 may be set as the "intermediate portion", and the intermediate portion may be brought into contact with the first restricting member 100C. Similarly, in this embodiment, the through hole N of the second holder 41 is regarded as the "intermediate portion". However, other portions of the second holder 41 may be set as the "intermediate portion", and the intermediate portion may be brought into contact with the second restricting member 110C. The "intermediate portion" may be a groove portion instead of a through hole. Further, the through hole M and the first restricting member 100C may be realized by the key groove 23 and the key 32. Further, the through hole N and the second restricting member 110C may be realized by the key groove 43 and the key 52.

[0109] Also according to this embodiment, substantially the same effects as those of the first embodiment can be achieved. Further, according to this embodiment, since the first restricting member 100C and the second restricting member 110C are provided on the outer peripheral surfaces of the first slide shaft 31 and the second slide shaft 51, respectively, interference with the first elastic member 61 and the second elastic member 71 housed inside the first holder 21 and the second holder 41 can be avoided. Therefore, for example, even when the restricting members cannot be housed inside the first holder 21 and the second holder 41 together with the elastic members due to the influence of the structure, shape, operation, or function of the elastic members, the movement of the stirring pin 60 and the shoulder 70 can be restricted by the first restricting member 100C and the second restricting member 110C provided on the outer peripheral surface. Therefore, the degree of freedom in design can be increased.

[0110] [6. Fifth Embodiment] Next, with reference to FIGS. 13 and 14, the rotary tool 1D according to the fifth embodiment will be described. The rotary tool 1D according to the fifth embodiment includes a main body portion 10 having a first holder 21, a first slide shaft 31, a second holder 41, and a second slide shaft 51, a stirring pin 60, a first elastic member 61, a shoulder 70, a second elastic member 71, a first restricting member 100D, and a second restricting member 110D. Since the basic configuration is the same as that of the above-described embodiment, the same reference numerals are given and the description thereof is omitted.

[0111] The first regulating member (first tip-side regulating member) 100D according to the present embodiment is fixedly provided on the outer peripheral surface of the tip side of the first slide shaft 31. The first regulating member 100D is a plate-like member that projects radially outward perpendicular to the outer peripheral surface of the first slide shaft 31. The first regulating member 100D may be single or a plurality may be formed. As shown in FIG. 14, until the first elastic member 61 reaches the maximum deflection amount, the first regulating member 100D abuts against the tip portion 21a of the first holder 21, and the movement of the first slide shaft 31 and the base end side of the stirring pin 60 can be restricted.

[0112] The second regulating member (second tip-side regulating member) 110D is fixedly provided on the outer peripheral surface of the tip side of the second slide shaft 51. The second regulating member 110D is a plate-like member that projects radially outward perpendicular to the outer peripheral surface of the second slide shaft 51. The second regulating member 110D may be single or a plurality may be formed. As shown in FIG. 14, until the second elastic member 71 reaches the maximum deflection amount, the second regulating member 110D abuts against the bottom portion 45a (the tip portion of the second holder 41) of the shoulder storage recess 45 of the second holder 41, and the movement of the second slide shaft 51 and the base end side of the shoulder 70 can be restricted.

[0113] Even with this embodiment, substantially the same effects as those of the first embodiment can be achieved. Further, according to this embodiment, since the first restricting member 100D and the second restricting member 110D are provided on the outer peripheral surfaces of the first slide shaft 31 and the second slide shaft 51, respectively, interference with the first elastic member 61 and the second elastic member 71 housed inside the first holder 21 and the second holder 41 can be avoided. For this reason, for example, even when the restricting members cannot be housed together with the elastic members inside the first holder 21 and the second holder 41 due to the influence of the structure, shape, operation, or function of the elastic members, the movement of the stirring pin 60 and the shoulder 70 can be restricted by the first restricting member 100D and the second restricting member 110D provided on the outer peripheral surfaces. Therefore, the degree of freedom in design can be increased. Also, the through hole M and the first restricting member 100C are realized by the key groove 23 and the key 32, and according to this embodiment, compared with the case where the first restricting member 100C and the key groove 23 are in contact, since the first restricting member 100D and the tip portion 21a of the first holder 21 are in contact, it is possible to avoid applying a load to the key groove 23.

[0114] [7. Sixth Embodiment] Next, with reference to FIGS. 15 and 16, the rotary tool 1E according to the sixth embodiment will be described. The rotary tool 1E according to the sixth embodiment includes a main body portion 10 having a first holder 21, a first slide shaft 31, a second holder 41, and a second slide shaft 51, a stirring pin 60, a first elastic member 61, a shoulder 70, a second elastic member 71, a first restricting member 100E, and a second restricting member 110E. Since the basic configuration is the same as that of the first embodiment, the same reference numerals are given and the description thereof is omitted.

[0115] The first restricting member (first tip restricting member) 100E according to this embodiment is fixedly provided at the tip portion 31a of the first slide shaft 31. The first restricting member 100E projects outward from the outer peripheral surface of the first slide shaft 31. The first restricting member 100E may be singular or plural in number.

[0116] The second regulating member (second tip regulating member) 110E is fixed to the tip 51a of the second slide shaft 51. The second regulating member 110E protrudes outward from the outer peripheral surface of the second slide shaft 51. The second regulating member 110E may be singular or plural in number.

[0117] As shown in FIG. 16, before the first elastic member 61 reaches the maximum deflection amount, the first regulating member 100E abuts against the tip 21a of the first holder 21, and the movement of the first slide shaft 31 and the proximal end side of the stirring pin 60 can be restricted. Further, before the second elastic member 71 reaches the maximum deflection amount, the second regulating member 110E abuts against the bottom 45a (the tip of the second holder 41) of the shoulder housing recess 45 of the second holder 41, and the movement of the second slide shaft 51 and the proximal end side of the shoulder 70 can be restricted.

[0118] Also according to the present embodiment, substantially the same effects as those of the first embodiment can be achieved. Further, according to the present embodiment, since the first regulating member 100E and the second regulating member 110E are provided at the tips of the first slide shaft 31 and the second slide shaft 51, respectively, interference with the first elastic member 61 and the second elastic member 71 housed inside the first holder 21 and the second holder 41 can be avoided. For this reason, for example, even when the regulating member cannot be housed inside the first holder 21 and the second holder 41 together with the elastic member due to the influence of the structure, shape, operation, or function of the elastic member, the first regulating member 100E and the second regulating member 110E provided at the tips can regulate the movement of the stirring pin 60 and the shoulder 70, respectively. Therefore, the degree of freedom in design can be increased. Also, according to the present embodiment, since the first regulating member 100E abuts against the tip 21a of the first holder 21, it is possible to avoid applying a load to the key groove 23, as compared with the case where the through hole M and the first regulating member 100C are realized by the key groove 23 and the key 32 and the first regulating member 100C abuts against the key groove 23.

[0119] [8. Seventh Embodiment] Next, with reference to FIGS. 17 and 18, the rotary tool 1F according to the seventh embodiment will be described. The rotary tool 1F according to the seventh embodiment includes a main body 10 having a first holder 21, a first slide shaft 31, a second holder 41, and a second slide shaft 51, a stirring pin 60, a first elastic member 61, a shoulder 70, and a second elastic member 71. Since the basic configuration is the same as that of the first embodiment described above, the same reference numerals are given and the description thereof is omitted.

[0120] In this embodiment, the stirring pin 60 serves as the first regulating member. Also, the shoulder 70 serves as the second regulating member. The outer diameter of the base end portion 63 of the stirring pin 60 is larger than the outer diameter of the first slide shaft 31. Also, the outer diameter of the base end portion 63 of the stirring pin 60 is larger than the inner diameter of the first storage recess 22 of the first holder 21. Furthermore, the outer diameter of the base end portion 74 of the shoulder 70 is larger than the outer diameter of the second slide shaft 51. Also, the width of the base end portion 74 of the shoulder 70 is larger than the width of the second storage recess 42. As shown in FIG. 18, before the first elastic member 61 reaches the maximum deflection amount, the base end portion 63 of the stirring pin 60 abuts against the tip end portion 21a of the first holder 21, and the movement of the first slide shaft 31 and the base end side of the stirring pin 60 can be restricted.

[0121] Also, before the second elastic member 71 reaches the maximum deflection amount, the base end portion 74 of the shoulder 70 abuts against the bottom portion 45a (the tip end portion of the second holder 41) of the shoulder storage recess 45 of the second holder 41, and the movement of the second slide shaft 51 and the base end side of the shoulder 70 can be restricted.

[0122] Also according to this embodiment, effects substantially equivalent to those of the first embodiment can be achieved. Further, according to this embodiment, by the stirring pin 60 and the shoulder 70 functioning as regulating members, interference with the first elastic member 61 and the second elastic member 71 respectively accommodated inside the first holder 21 and the second holder 41 can be avoided. For this reason, for example, even when the regulating members cannot be housed together with the elastic members inside the first holder 21 and the second holder 41 due to the influence of the structure, shape, movement, or function of the elastic members, the movement of the stirring pin 60 and the shoulder 70 themselves can be regulated by the stirring pin 60 and the shoulder 70. Therefore, the degree of freedom in design can be increased.

[0123] [9. Others] Although the embodiments of the present invention have been described above, design changes can be appropriately made within a range not contrary to the gist of the present invention. In the above embodiment, the key groove 23 is formed in the first holder 21 and the key 32 is formed in the first slide shaft 31, but the present invention is not limited to this. A key may be formed in the first holder 21 and a key groove may be formed in the first slide shaft 31. Similarly, for the second holder 41 and the second slide shaft 51, the positional relationship between the key and the key groove may be reversed, a key may be formed in the second holder 41, and a key groove may be formed in the second slide shaft 51. In such a case, the same operational effects as those of the above embodiment can be obtained.

[0124] In the above-described embodiment, the case where the rotary tool 1 includes a holding portion 80 fixed to the second holder 41 and this holding portion is connected to the joining device 3 to hold the shoulder 70 in a non-rotating state is illustrated, but the present invention is not limited thereto. For example, the joining device 3 may include a rod-shaped arm member fixed to the fixing system of the joining device 3 as a second holding portion, and this second holding portion may be connected to the second holder 41 of the rotary tool 1 to hold the shoulder 70 in a non-rotating state. This second holding portion is included in the joining device 3. Further, the rotary tool 1 may include a rod-shaped arm member fixed to the second holder 41 as a holding portion 80, and the joining device 3 may include a rod-shaped arm member fixed to the fixing system of the joining device 3 as a second holding portion, and the two holding portions may be connected to each other to hold the shoulder 70 in a non-rotating state. This holding portion is included in the rotary tool 1 and the joining device 3. As described above, the holding portion included in the rotary tool 1 and the second holding portion included in the joining device 3 and operating in cooperation with the holding portion included in the rotary tool 1 may be provided simultaneously. Further, the fixing means may be in other shapes such as a rod-shaped arm member (included in the rotary tool 1) fixed to the shoulder 70 as the holding portion 80, or a rod-shaped arm member (included in the joining device 3) connecting the fixing system of the joining device 3 and the shoulder 70. As described above, by providing the joining device 3 with the second holding portion that holds the shoulder 70 in a non-rotating state, it becomes easier to hold the shoulder 70 in a non-rotating state, and the finish of the surface of the joined member 2 after friction stir joining becomes even better.

[0125] Furthermore, the first elastic member 61 may be disposed anywhere as long as it biases the stirring pin 60 toward the tip side. Also, the arrangement of the regulating member may be changed according to the arrangement of the first elastic member 61. For example, it may be disposed so as to surround the lower part of the first slide shaft 31 and provided between the tip part 21a of the first holder 21 and the base end part 63 of the stirring pin 60. Similarly, the second elastic member 71 may also be disposed so as to surround the lower part of the second slide shaft 51 and provided between the bottom part 45a of the shoulder storage recess 45 (the tip part of the second holder 41) and the base end part 74 of the shoulder 70. In such a case, the first elastic member 61 is positioned near the intermediate part between the first slide shaft 31 and the stirring pin 60, and the first elastic member 61 acts evenly in the circumferential direction of the first slide shaft 31. Therefore, even when the first slide shaft 31 moves, the first elastic member 61 stably biases the stirring pin 60 toward the tip side. Therefore, the accuracy of load control of the stirring pin 60 can be improved.

[0126] In the above embodiment, the case where the tip part 62 of the stirring pin 60 protrudes below the tip part 73 of the shoulder 70 is illustrated, but the present invention is not limited thereto. In a state where the rotary tool 1 is not in contact with the workpiece 2, the tip part 73 of the shoulder 70 may protrude below the tip part 62 of the stirring pin 60. Thereby, when pulling out the rotary tool 1 from the workpiece 2, when moving the rotary tool 1 away from the workpiece 2, the stirring pin 60 disengages from the workpiece 2 before the shoulder 70 while the shoulder 70 presses the workpiece 2. At this time, while maintaining the state where the shoulder 70 presses the workpiece 2, by pulling out the stirring pin 60, the shoulder 70 can hold down the metal material that has flowed out due to the insertion of the stirring pin 60. Therefore, the hole formed when pulling out the stirring pin 60 can be easily filled with the metal material held down by the shoulder 70. In particular, when performing friction stir welding at a spot where welding is performed at the position where the rotary tool 1 is inserted during friction stir welding and pulled out without moving from the insertion position, it becomes easier to prevent the formation of a hole.

[0127] In addition, in the above-described embodiment, the case where the first restricting member 100 has a columnar shape and the first restricting member 100 is disposed in the hollow portion of the first elastic member 61 has been described as an example. Further, the case where the second restricting member 110 is disposed in the hollow portion of the second elastic member 71 has been described as an example. The first restricting member may have a cylindrical shape with an inner diameter larger than the outer diameter of the first elastic member 61. In this case, the first elastic member 61 may be disposed inside the first restricting member, and the first restricting member may be disposed so as to cover the outside of the first elastic member 61. Further, the second restricting member may have a cylindrical shape with an inner diameter larger than the outer diameter of the second elastic member 71. In this case, the second elastic member 71 may be disposed inside the second restricting member, and the second restricting member may be disposed so as to cover the outside of the second elastic member 71.

Explanation of Signs

[0128] 1 Rotating tool 2 Workpiece to be joined 3 Joining device 10 Main body portion 11 Fixing portion 12 Rotating shaft 21 First holder 23 Key groove 31 First slide shaft 32 Key 41 Second holder 43 Key groove 51 Second slide shaft 52 Key 60 Stirring pin 61 First elastic member 70 Shoulder 71 Second elastic member 80 Holding portion 100 First restricting member 110 Second restricting member

Claims

1. A rotary tool used in a joining device for friction stir joining of joined members, having a fixed part attached and fixed to the joining device, and a main body part having a rotating shaft for transmitting a rotational force from the joining device, a stirring pin that is disposed on the main body part so as to be rotatable and movable in the axial direction of the rotating shaft upon receiving the rotational force from the main body part, and that is inserted into the joined member to perform friction stirring on the joined member, a shoulder that is configured separately from the stirring pin, is not subjected to the rotational force from the main body part, is disposed on the main body part so as to be movable individually with respect to the stirring pin in the axial direction of the rotating shaft, and presses the joined member in a state of being in contact with the joined member, a first elastic member that biases the stirring pin toward the tip side in the axial direction of the rotating shaft, and a first regulating member that regulates the movement of the stirring pin toward the base end side in the axial direction of the rotating shaft, and is provided with, The first regulating member regulates the movement of the stirring pin such that the amount of deformation generated in the first elastic member as the stirring pin moves does not exceed the maximum allowable capacity of the first elastic member. A rotary tool characterized by this.

2. a second elastic member that biases the shoulder toward the tip side in the axial direction of the rotating shaft, and a second regulating member that regulates the movement of the shoulder toward the base end side in the axial direction of the rotating shaft, and is provided with, The second regulating member regulates the movement of the shoulder such that the amount of deformation generated in the second elastic member as the shoulder moves does not exceed the maximum allowable capacity of the second elastic member. The rotary tool according to claim 1.

3. The main body part further has a hollow cylindrical first holder attached to the rotating shaft, and a first slide shaft that is slidably accommodated in the central part of the first holder in the rotating shaft direction and rotates synchronously with the first holder, The stirring pin is provided at the tip of the first slide shaft. The first slide shaft is biased toward the tip side of the stirring pin via the first elastic member. The first restricting member restricts the first slide shaft from moving toward the proximal end side in the axial direction of the rotating shaft. The rotary tool according to claim 2.

4. The main body portion further includes a hollow cylindrical second holder provided rotatably relative to the outer periphery of the first holder, and a second slide shaft slidably accommodated inside the second holder in the axial direction of the rotating shaft. The shoulder is provided at the tip of the second slide shaft. The second slide shaft is biased toward the tip side of the shoulder via the second elastic member. The second restricting member restricts the second slide shaft from moving toward the proximal end side in the axial direction of the rotating shaft. The rotary tool according to claim 3.

5. The first restricting member is provided inside the first holder. As the first slide shaft moves, the movement of the first slide shaft is restricted by contact between the proximal end portion of the first slide shaft, the bottom portion on the proximal end side of the first holder, and the first restricting member. The rotary tool according to claim 3.

6. The second restricting member is provided inside the second holder. As the second slide shaft moves, the movement of the second slide shaft is restricted by contact between the proximal end portion of the second slide shaft, the bottom portion on the proximal end side of the second holder, and the second restricting member. The rotary tool according to claim 4.

7. The first restricting member is provided at the bottom portion on the proximal end side of the first holder. As the first slide shaft moves, the movement of the first slide shaft is restricted by contact between the proximal end portion of the first slide shaft and the first restricting member. The rotary tool according to claim 3.

8. The second restricting member is provided at the bottom of the proximal end side of the second holder, As the second slide shaft moves, the proximal end portion of the second slide shaft comes into contact with the second restricting member, thereby restricting the movement of the second slide shaft. The rotary tool according to claim 4.

9. The first restricting member is provided at the proximal end portion of the first slide shaft, As the first slide shaft moves, the bottom of the proximal end side of the first holder comes into contact with the first restricting member, thereby restricting the movement of the first slide shaft. The rotary tool according to claim 3.

10. The second restricting member is provided at the proximal end portion of the second slide shaft, As the second slide shaft moves, the bottom of the proximal end side of the second holder comes into contact with the second restricting member, thereby restricting the movement of the second slide shaft. The rotary tool according to claim 4.

11. The first restricting member is provided on the outer peripheral surface of the first slide shaft, As the first slide shaft moves, the intermediate portion of the first restricting member and the first holder comes into contact, thereby restricting the movement of the first slide shaft. The rotary tool according to claim 3.

12. The second restricting member is provided on the outer peripheral surface of the second slide shaft, As the second slide shaft moves, the intermediate portion of the second restricting member and the second holder comes into contact, thereby restricting the movement of the second slide shaft. The rotary tool according to claim 4.

13. The first restricting member is provided on the outer peripheral surface of the first slide shaft, As the first slide shaft moves, the first regulating member comes into contact with the tip of the first holder, thereby regulating the movement of the first slide shaft. The rotary tool according to claim 3.

14. The second regulating member is provided on the outer peripheral surface of the second slide shaft. As the second slide shaft moves, the second regulating member comes into contact with the tip of the second holder, thereby regulating the movement of the second slide shaft. The rotary tool according to claim 4.

15. The first regulating member is provided at the tip of the first slide shaft. As the first slide shaft moves, the first regulating member comes into contact with the tip of the first holder, thereby regulating the movement of the first slide shaft. The rotary tool according to claim 3.

16. The second regulating member is provided at the tip of the second slide shaft. As the second slide shaft moves, the second regulating member comes into contact with the tip of the second holder, thereby regulating the movement of the second slide shaft. The rotary tool according to claim 4.

17. The stirring pin is the first regulating member. As the first slide shaft moves, the stirring pin comes into contact with the tip of the first holder, thereby regulating the movement of the first slide shaft. The rotary tool according to claim 3.

18. The shoulder is the second regulating member. As the second slide shaft moves, the shoulder comes into contact with the tip of the second holder, thereby regulating the movement of the second slide shaft. The rotary tool according to claim 4.

19. A joining device comprising the rotary tool according to any one of claims 1 to 18, power means for outputting a rotational force transmitted to the rotary shaft of the rotary tool, and position control means for holding the fixed portion of the rotary tool and performing position control of the rotary tool, moving the rotary tool to a predetermined height position with respect to the member to be joined by the position control means, inserting the stirring pin into the member to be joined, and performing friction stir joining on the member to be joined, A joining device characterized by the above.

20. Moving the rotary tool according to any one of claims 1 to 18 to a predetermined height position with respect to the member to be joined, inserting the stirring pin into the member to be joined, and performing friction stir joining on the member to be joined, A joining method characterized by the above.

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