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 50 which performs friction stir welding of the member to be welded; and a shoulder 60 which presses the member to be welded. The stirring pin 50 and the shoulder 60 further comprise: a first elastic member 51 which constitutes an assembly 70 and energizes the assembly 70 toward a tip side of the stirring pin 50; and a first regulation member 100 which regulates movement of the assembly 70 to a base end side in an axial direction of a rotation axis. The first regulation member 100 regulates movement of the assembly 70 so that a deformation quantity generated in the first elastic member 51 with movement of the assembly may not exceed a maximum allowable quantity of the first elastic member 51.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 welding.

Background Art

[0002] As joining devices for performing friction stir welding, 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] The joining device of Patent Document 1 has a complex structure and is expensive because it performs load control. 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 capable of performing load control while 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 fixed portion attached and fixed to the joining device and a rotary shaft for transmitting a rotational force from the joining device; a stirring pin disposed rotatably and axially movably with respect to the main body, receiving the rotational force from the main body, inserted into the member to be joined, and performing friction stirring on the member to be joined; and a shoulder provided separately from the stirring pin, disposed movably axially with respect to the main body without receiving the rotational force from the main body, and pressing the member to be joined in a state of contacting the member to be joined. The stirring pin and the shoulder are configured to be relatively rotatable and integrally movable axially with respect to the rotary shaft to form an assembly. Furthermore, a first elastic member for biasing the assembly toward the tip side of the stirring pin axially with respect to the rotary shaft, and a first regulating member for regulating movement of the assembly toward the base end side axially of the rotary shaft are provided. The first regulating member regulates the movement of the assembly such that the amount of deformation generated in the first elastic member as the assembly moves does not exceed the maximum allowable capacity of the first elastic member.

[0008] Further, the main body portion further includes a hollow cylindrical holder attached to the rotating shaft, and a slide shaft that is slidably accommodated in the central portion of the holder in the axial direction of the rotating shaft and rotates synchronously with the holder. The assembly is provided at the tip of the slide shaft, and the slide shaft is biased toward the tip side of the assembly via the first elastic member. It is preferable that the first restricting member restricts the slide shaft from moving toward the proximal end side in the axial direction of the rotating shaft.

[0009] Furthermore, a second elastic member that biases the shoulder toward the tip side of the stirring pin with respect to the axial direction of the rotating shaft, and a second restricting member that restricts the shoulder from moving toward the proximal end side in the axial direction of the rotating shaft are further provided. It is preferable that the second restricting member restricts the movement of the shoulder so that the amount of deformation generated in the second elastic member due to the movement of the shoulder does not exceed the maximum allowable capacity of the second elastic member.

[0010] Further, the first restricting member is provided in the holder, and it is preferable that the movement of the slide shaft is restricted by the contact between the proximal end portion of the slide shaft, the bottom portion on the proximal end side of the holder, and the first restricting member as the slide shaft moves.

[0011] Further, the first restricting member is provided at the bottom portion on the proximal end side of the holder, and it is preferable that the movement of the slide shaft is restricted by the contact between the proximal end portion of the slide shaft and the first restricting member as the slide shaft moves.

[0012] Further, the first restricting member is provided at the proximal end portion of the slide shaft, and it is preferable that the movement of the slide shaft is restricted by the contact between the bottom portion on the proximal end side of the holder and the first restricting member as the slide shaft moves.

[0013] Further, the first restricting member is provided on the outer peripheral surface of the slide shaft, and it is preferable that the movement of the slide shaft is restricted by the contact between the first restricting member and the intermediate portion of the holder as the slide shaft moves.

[0014] Further, it is preferable that the first restricting member is provided on the outer peripheral surface of the slide shaft, and the movement of the slide shaft is restricted by the contact between the first restricting member and the tip of the holder as the slide shaft moves.

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

[0016] Further, it is preferable that the stirring pin is the first restricting member, and the movement of the slide shaft is restricted by the contact between the stirring pin and the tip of the holder as the slide shaft moves.

[0017] Moreover, the present invention is a joining device including the rotary tool according to any one of claims 1 to 10, 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 is performed on the member to be joined.

[0018] Moreover, the rotary tool according to any one of claims 1 to 10 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 is performed on the member to be joined.

Effects of the Invention

[0019] 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 member to be joined, the stirring pin can be inserted while using the elastic member.

Brief Description of the Drawings

[0020]

Figure 1

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Embodiments for Carrying Out the Invention

[0021] 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 represented components may be different from the actual ones.

[0022] [1. First Embodiment] [1-1. Rotary Tool] First, the configuration of the rotary tool according to this embodiment will be described. As shown in FIG. 1, the rotary tool 1 according to this embodiment is used in a joining device 3 (see FIG. 1) for friction stir joining of a joined member 2 (see FIG. 5), and is inserted while rotating into the butting portion of the joined member 2. Such a rotary tool 1 includes a main body portion 10, a stirring pin 50, a shoulder 60, a first elastic member 51, and a first restricting member 100. The stirring pin 50 and the shoulder 60 are relatively rotatable and are attached so as to move in the axial direction of the rotation axis integrally, constituting an assembly 70. Also, the rotary tool 1 includes a holding portion 80 (see FIG. 3).

[0023] <Main Body Portion> The main body part 10 is a part fixed to a joining device 3 such as a machining center, etc., and includes a fixing part 11 and a rotating shaft 12. The fixing part 11 is a part that is attached to and fixed to the joining device 3, and has a cylindrical shape. The fixing part 11 is a chuck mechanism, and by cooperating with a paired chuck mechanism provided on the joining device 3, the fixing part 11 can be detachably fixed to the joining device. Examples of the chuck mechanism include a groove provided on the fixing part 11 and a claw provided on the joining device 3 that fits into and sandwiches the groove on the fixing part 11 side. The rotating shaft 12 is connected and provided on the other end side (the lower side in FIG. 1) of the fixing part 11, which is the side attached to the joining device 3. The rotating shaft 12 has a cylindrical shape. The rotating shaft 12 is a part that transmits the rotational force from the joining device 3 to the stirring pin 50, and is connected to a rotating shaft (not shown) of the joining device 3 via the fixing part 11.

[0024] As also shown in FIGS. 2 and 3, the main body part 10 further includes a holder 21 and a slide shaft 31.

[0025] <holder> The holder 21 is attached to the rotating shaft 12, rotates synchronously with the rotating shaft 12, and is a part that supports the slide shaft 31 and the stirring pin 50. The holder 21 has a bottomed cylindrical shape (hollow cylindrical shape) with its upper part closed, and the internal hollow part is a storage recess 22 into which the slide shaft 31 is inserted. The storage recess 22 has a cylindrical shape, and the lower side (the lower side in FIG. 1) in the axial direction of the rotating shaft 12 is open. A key groove 23 is formed in the cylindrical body part of the holder 21. The key groove 23 is formed in an elongated oval shape along the axial direction (the vertical direction in FIG. 1) of the rotating shaft 12, and penetrates from the outer peripheral surface to the inner peripheral surface of the holder 21. Note that the key groove 23 does not have to penetrate the cylindrical body part, and may be formed in a groove shape on the inner peripheral surface of the cylindrical body part. The key grooves 23 are arranged at 180° intervals in the circumferential direction of the cylindrical body part, 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 may be 3 or more.

[0026] <slide shaft> The slide shaft 31 is housed in a storage recess 22 at the center of the holder 21 so as to be slidable in the rotational axis direction (the vertical direction in FIG. 1) and rotates synchronously (rotates together) with the holder 21. The slide shaft 31 has a cylindrical shape and an outer diameter that can be housed in the storage recess 22. A key 32 that protrudes outward is provided on the outer peripheral surface of the slide shaft 31. The key 32 is fixed at the base end portion of the slide shaft 31 (the end portion on the side of the rotary shaft 12: 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 rotational axis direction, has the same width dimension as 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 circular, elliptical, long elliptical, rectangular, etc. may be used as long as it has the same width dimension as the key groove 23. A stirring pin 50 is integrally provided at the tip end portion of the slide shaft 31 (the end portion on the side away from the joining device 3: the lower end portion in FIG. 1). Therefore, the stirring pin 50 is biased toward the tip end side of the slide shaft 31 (the side away from the joining device 3: the lower side in FIG. 1) by being biased toward the tip end side by the first elastic member 51.

[0027] <Stirring pin> The stirring pin 50 is a part that receives the rotational force from the main body 10 and is inserted into the joined member 2 while rotating to perform friction stirring on the joined member 2. The stirring pin 50 is formed, for example, of tool steel in a cylindrical shape. The tip 52 (the lower end in FIG. 1) of the stirring pin 50 tapers toward the tip. The tip of the tip 52 of the stirring pin has a flat surface perpendicular to the axial direction. A flange portion 53 with an enlarged diameter is integrally formed at the base end portion of the stirring pin 50. The flange portion 53 is integrally formed with the slide shaft 31, and the stirring pin 50 and the flange portion 53 move in the axial direction of the rotation axis by the sliding movement of the slide shaft 31. The flange portion 53 has a larger diameter than the slide shaft 31, and a ring-shaped stepped portion 54 is formed at the connecting portion between the flange portion 53 and the slide shaft 31 (the base end portion of the flange portion 53) in a plan view. The flange portion 53 functions as a receiving portion that receives the elastic force of the first elastic member 51 from the base end side of the slide shaft 31 (the side closer to the joining device 3: the upper side in FIG. 1). Further, the flange portion 53 also functions as a supporting portion that supports a shoulder 60 provided on the tip side (the lower side in FIG. 1) of the stirring pin 50.

[0028] <Shoulder> The shoulder 60 is a part that presses the joined member 2 in a state of being in contact with the joined member 2. The shoulder 60 is configured separately from the stirring pin 50, is provided so as to be relatively rotatable with respect to the stirring pin 50, and is not adapted to receive the rotational force from the main body 10. The shoulder 60 is non-movable relative to the stirring pin 50 and the rotation axis 12 in the axial direction, and moves in the axial direction together with the stirring pin 50. That is, the shoulder 60 is movable in the axial direction with respect to the holder 21. Specifically, the shoulder 60 is formed, for example, of tool steel. The shoulder 60 has a cylindrical shape and is coaxially arranged so as to surround the stirring pin 50. That is, the stirring pin 50 is inserted into the hollow portion 61 of the shoulder 60. The base end portion (the upper end in FIG. 1) of the hollow portion 61 is open, and a bearing 63 is interposed between the stirring pin 50 and the shoulder 60. The bearing 63 is arranged so as to surround the stirring pin 50. Thereby, the shoulder 60 is relatively rotatable with respect to the stirring pin 50 and non-movable in the axial direction.

[0029] The tip (tip surface) of the shoulder 60 is at the same height as the base end portion of the tapered surface of the tip portion 52 of the stirring pin 50. That is, the tip portion 52 of the stirring pin 50 protrudes toward the tip side from the tip surface of the shoulder 60. The shoulder 60 moves in the axial direction of the rotation shaft 12 together with the stirring pin 50 integrally connected to the slide shaft 31 by the slide movement of the slide shaft 31.

[0030] As described above, the stirring pin 50 and the shoulder 60 are integrated and together form an assembly 70 that moves in the axial direction of the rotation shaft 12. That is, the assembly 70 is provided at the tip of the slide shaft 31.

[0031] <First elastic member> The first elastic member 51 is a part that biases the assembly 70 including the stirring pin 50 and the shoulder 60 toward the tip side with respect to the axial direction of the rotation shaft. The first elastic member 51 is constituted by, for example, a coil spring, is housed inside the holder 21, and is mounted between the base end portion 31b of the slide shaft 31 and the bottom portion 22a of the storage recess 22 of the holder 21. The first elastic member 51 is capable of biasing the assembly 70 toward the tip side against the force received from the assembly 70 side.

[0032] The elasticity of the first elastic member 51 is set such that when the stirring pin 50 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 stirring pin 50 is displaced and inserted within a predetermined range within the entire movable range of the stirring pin 50 by the first elastic member 51.

[0033] For example, when the first elastic member 51 is a coil spring and the load applied to the first elastic member 51 is inserted in the range of 100 kg to 5 t, the deflection amount of the first elastic member 51 is in the range of 0 to 30% with respect to the free length of the first elastic member 51. In this deformed state, the stirring pin 50 is inserted into the joined member 2, and the shoulder 60 is set to press the joined member 2. Thereby, when the stirring pin 50 is pushed into the joined member 2 at a certain height, even when the height of the joined member 2 changes, the first elastic member 51 deforms in accordance with the change of the joined member, making it easier to keep the insertion amount of the stirring pin 50 constant.

[0034] Note that the first elastic member 51 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 51 may be a fluid spring using pneumatic pressure, gas pressure, or hydraulic pressure, or a magnetic spring using magnetic force or electromagnetic force.

[0035] The first elastic member 51 may be set to satisfy the relationship between the deformation amount and the elastic modulus when the stirring pin 50 is inserted to a predetermined depth in consideration of the joining conditions. Further, the first elastic member 51 may be set to satisfy the relationship between the deformation amount and the elastic modulus such that the shoulder 60 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. Examples of the joining conditions that affect the setting of the first elastic member 51 include conditions of the joined member such as the material of the joined member 2 and the shape of the joined portion, and joining modes such as the insertion depth of the stirring pin 50, the shape of the rotary tool 1, the rotation speed, and the moving speed.

[0036] Note that the shoulder 60 only needs to be in contact with the joined member 2 at least partially, and there may be a slight space between the shoulder 60 and the joined member 2 according to the surface shape of the joined member 2. However, it is preferable that the shoulder 60 is in contact with the joined member 2 without a gap so that the metal material overflowed by friction stir welding can be pressed to prevent the generation of burrs. Also, the shoulder 60 may be inserted into the joined member 2 to some extent, but it is preferable that the shoulder 60 is not deeply inserted into the joined member 2 so that no recess is formed due to the contact between the joined member 2 and the shoulder 60 after joining.

[0037] <First restricting member> As shown in FIG. 1 and the like, the first restricting member (first loose-fitting restricting member) 100 is a member that restricts the movement of the stirring pin 50 to the proximal end side of the rotation shaft 12 beyond a predetermined range. 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 51 inside the 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 welding. In the present embodiment, the first restricting member 100 has a cylindrical shape, but it may be appropriately formed according to the shape of the placement location. The first restricting member 100 restricts the movement of the stirring pin 50 so that the amount of deformation generated in the first elastic member 51 as the stirring pin 50 moves does not exceed the maximum deflection amount (maximum allowable amount) of the first elastic member 51.

[0038] For example, the maximum deflection amount of the first elastic member 51 according to the present embodiment is set when the first elastic member 51 is deformed by 30% with respect to its free length. The maximum deflection amount means the amount by which the first elastic member 51 is most compressed when expressing its elastic force. If the maximum deflection amount is exceeded, the elastic force of the first elastic member 51 may not be exerted as expected, or the first elastic member 51 may be damaged earlier than expected.

[0039] As shown in FIG. 2, in this embodiment, when the amount of deflection of the first elastic member 51 is 30% with respect to the free length of the first elastic member 51, the tip portion (tip surface) 100a of the first restricting member 100 abuts on the base end portion 31b of the slide shaft 31, and the base end portion (base surface) 100b abuts on the bottom portion 22a. Thereby, it is possible to prevent the first elastic member 51 from deforming beyond the maximum amount of deflection. The maximum amount of deflection of the first elastic member 51 can be appropriately set according to the first elastic member 51 and the first restricting member 100. The maximum amount of deflection of the first elastic member 51 may be, for example, 25%, 20%, 15%, 10%, or 5%.

[0040] In this embodiment, since the first elastic member 51 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 developed or the elastic member may be damaged, and such an amount is defined as the "maximum allowable capacity".

[0041] Further, in this embodiment, the first restricting member 100 is a solid such as metal, and restricts the movement of the stirring pin 50 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 non - contactingly restrict the movement of the stirring pin 50.

[0042] Also, as long as the first restricting member 100 restricts the movement of the assembly 70, its shape and arrangement are not limited. For example, a part of the main body 10 or the stirring pin 50 may function as the first restricting member 100, the first restricting member 100 may be provided by being integrally formed with the main body 10 or the stirring pin 50, or the first restricting member 100 may be provided in a form in which a separate member is attached to the main body 10 or the stirring pin 50.

[0043] <Retention portion> As shown in FIG. 3, the holding part 80 is a rod-shaped arm-like member, and the tip part thereof is fixed to the outer peripheral surface of the shoulder 60. The base end part of the holding part 80 is connected to the fixing system on the side of the joining device 3 and is configured to hold the shoulder 60 in a non-rotating state. This holding part 80 is included in the rotary tool 1. The shoulder 60 is provided so as to be relatively rotatable with respect to the rotary shaft 12, the holder 21, and the stirring pin 50, and is further held in a non-rotating state by the holding part 80. Thereby, even when the stirring pin 50 rotates, the shoulder 60 can be held in a non-rotating state.

[0044] [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 based on the position information input in advance, operates the power means to move the rotary tool 1. The power means moves the rotary tool 1 in the three axial directions of XYZ.

[0045] [1-3. Joining Method] Next, the joining method according to the present invention will be described with reference to FIG. 5. In such a joining method, the rotary tool 1 of the present embodiment is moved to a predetermined height position set in advance with respect to the member to be joined 2, and while pressing the shoulder 60 of the rotary tool 1 against the member to be joined 2, the stirring pin 50 of the rotary tool 1 is inserted into the member to be joined 2 to perform friction stir joining on the member to be joined 2.

[0046] When inserting the stirring pin 50, as the rotary tool 1 is inserted in the insertion direction toward the joined member 2, first, the tip of the stirring pin 50 contacts the joined member 2. When the rotary tool 1 is further brought closer to the joined member 2, the first elastic member 51 is compressed, and while the elastic force of the first elastic member 51 that biases the stirring pin 50 toward the joined member 2 increases, the stirring pin 50 is inserted into the joined member.

[0047] When the rotary tool 1 is further brought closer to the joined member 2, the shoulder 60 contacts the joined member 2. As the first elastic member 51 is compressed, while the elastic force of the first elastic member 51 that biases the stirring pin 50 and the shoulder 60 toward the joined member 2 further increases, the shoulder 60 is pressed against the joined member 2. At this time, so that the deflection amount of the first elastic member 51 does not exceed the maximum deflection amount, with a margin remaining due to the deformation of the first elastic member 51, the stirring pin 50 is inserted into the joined member 2, and the first elastic member 51 and the joining conditions are set so that the shoulder 60 can be pressed against the joined member 2. Alternatively, with the movement of the assembly 70 restricted by the first restricting member 100 so that the deflection amount of the first elastic member 51 does not exceed the maximum deflection amount, the stirring pin 50 is inserted into the joined member 2 by being pressed against the joined member 2. Also, the first elastic member 51 and the joining conditions are set so that the shoulder 60 can press the joined member 2 without being inserted into the joined member 2 while being in contact with the joined member 2.

[0048] During joining by the rotary tool 1, as shown on the left side in FIG. 5, the assembly 70 including the stirring pin 50 and the shoulder 60 is biased toward the tip side by the first elastic member 51. Thereby, when there is no error in the height of the joined member 2 with respect to the set value, as shown on the left side in FIG. 5, the tip portion 52 of the stirring pin 50 is pushed into the joined member 2 at a desired depth. Also, the shoulder 60 is configured to be able to press the joined member 2 without being inserted into the joined member 2 while being in contact with the joined member 2.

[0049] Next, as shown in the center of FIG. 5, a case where the height of the member 2 to be joined becomes slightly higher than the set value due to an error during friction stir welding will be described. Here, if the first elastic member 51 did not exist and the stirring pin 50 was simply pushed into the member 2 to be joined as it was, compared to the case where there is no error in the height of the member 2 to be joined with respect to the set value, the insertion amounts of the stirring pin 50 and the shoulder 60 increase by the amount by which the height of the member 2 to be joined has increased.

[0050] On the other hand, when joining is performed by the rotary tool 1 of the present embodiment, when the height of the member 2 to be joined increases, the assembly 70 including the stirring pin 50 receives an upward reaction force from the member 2 to be joined and is pushed upward. At the same time, due to this upward push, the first elastic member 51 is compressed, and the assembly 70 receives a downward elastic force from the first elastic member 51 and is pushed downward. The positions of the stirring pin 50 and the shoulder 60 are changed to a position where the upward reaction force and the downward elastic force balance with each other as the height of the member 2 to be joined changes. The first elastic member 51 is set so that the insertion amounts of the stirring pin 50 and the shoulder 60 at this time are approximately the same as the insertion amounts when there is no error in the height of the member 2 to be joined with respect to the set value. If the elastic force of the first elastic member 51 is too weak, the upward reaction force accompanying the change in the height of the member 2 to be joined becomes larger, and the insertion amount becomes smaller. On the other hand, if the elastic force of the first elastic member 51 is too strong, the downward elastic force accompanying the change in the height of the member 2 to be joined becomes larger, and the insertion amount becomes larger. That is, even when the height of the member 2 to be joined fluctuates and increases, in the rotary tool 1, the first elastic member 51 is set so that the stirring pin 50 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 increases, in the rotary tool 1, the first elastic member 51 is set so that the shoulder 60 presses against the member 2 to be joined without being inserted into the member 2 to be joined while being in contact with the member 2 to be joined.

[0051] 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. 5, the first elastic member 51 extends and the assembly 70 including the stirring pin 50 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 51 is set so that the stirring pin 50 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 first elastic member 51 is set so that the shoulder 60 presses the member 2 to be joined without being inserted into the member 2 to be joined while being in contact with the member 2 to be joined.

[0052] As described above, in the rotary tool 1, due to the action of the first elastic member 51, the stirring pin 50 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 first elastic member 51, while keeping the shoulder 60 pressing the member 2 to be joined, the stirring pin 50 is inserted into the member 2 to be joined to perform friction stirring, so that the shoulder 60 can hold down the metal material overflowing from the insertion site of the stirring pin 50 due to the friction stirring by the stirring pin 50. Therefore, the generation of burrs can be reduced.

[0053] [1-4. Action and Effect] According to the rotary tool 1, the joining device 3, and the joining method according to the present embodiment, since the assembly 70 provided movably in the axial direction of the rotary shaft 12 is biased toward the tip side by the first elastic member 51, when the tip portion 52 of the stirring pin 50 is inserted into the member 2 to be joined, the stirring pin 50 is inserted to a predetermined depth according to the elasticity of the first elastic member 51. Further, since the assembly 70 is biased toward the tip side by the first elastic member 51, the shoulder 60 is pressed against the member 2 to be joined according to the elasticity of the first elastic member 51. By setting the first elastic member 51 in consideration of joining conditions such as the joining member and the joining mode, the stirring pin 50 can be inserted to a desired depth, and the member 2 to be joined can be held by the shoulder 60. That is, the rotary tool 1 can perform pseudo load control using the first elastic member 51.

[0054] 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 50 becomes substantially constant. On the other hand, when the rotary tool 1 of the present embodiment is used, even if the support height of the rotary tool 1 by the machining center is constant, the first elastic member 51 appropriately expands and contracts according to the variation in the height of the member 2 to be joined, and the assembly 70 moves in the axial direction. Thus, by utilizing the elasticity of the first elastic member 51, load control becomes possible in which the insertion depth of the stirring pin 50 into the member 2 to be joined and the contact mode of the shoulder 60 with the member 2 to be joined can be controlled.

[0055] Further, the rotary tool 1 is provided with a shoulder 60 that is disposed movably separately from the stirring pin 50 in the axial direction of the rotary shaft 12 without receiving the rotational force from the rotary shaft 12 and presses the member 2 to be joined. By the shoulder 60 pressing down the metal material that has overflowed from the insertion site of the stirring pin 50 due to friction stirring by the stirring pin 50, the generation of burrs can be reduced. In this way, the finish of the surface after friction stir joining is improved by the shoulder 60.

[0056] Here, regarding load control, when performing friction stir welding using, for example, a compression coil spring as an elastic member, a stirring pin could be inserted into a relatively soft aluminum alloy of the 1000 series, but there was a problem that a stirring pin could not be inserted into a hard aluminum alloy.

[0057] 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 the extent that it exceeds the maximum deflection amount of the compression coil spring. That is, it is difficult to insert the stirring pin while performing simple load control on a hard work piece to be joined 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.

[0058] By the way, for example, when bringing the stirring pin 50 into contact with the work piece 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 50 cannot catch up with the insertion of the stirring pin 50, and the generated reaction force is highest when the stirring pin 50 is pushed to a predetermined depth. When the stirring pin 50 is inserted into the work piece 2 to a 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 50 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".

[0059] FIG. 6 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 50 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. Up to point P1, it is a rising straight line on the right, indicating a state where the stirring pin 50 is being pushed into the workpiece 2. During friction stir welding, when the stirring pin 50 is pushed in, the generated reaction force gradually increases and heads towards a peak (point P1). As the stirring pin 50 progresses, the generated reaction force decreases slightly and then enters a steady state (point P2), and the generated reaction force becomes generally constant.

[0060] The rotary tool 1 according to the present embodiment includes a first regulating member 100 that regulates the movement of the stirring pin 50 toward the proximal end side in the axial direction. Thereby, when the rotary tool 1 is inserted and the generated reaction force (load) is maximum, or at a position where the shape of the workpiece 2 changes greatly, the amount of deflection generated in the first elastic member 51 is regulated by the first regulating member 100 within a range not exceeding the maximum deflection amount of the first elastic member 51. Therefore, even when the workpiece 2 is relatively hard and requires a large load, it is possible to avoid the first elastic member 51 from deforming beyond the limit. Thereby, the stirring pin 50 can be inserted while using the first elastic member 51 even for a relatively hard workpiece 2, and breakage of the first elastic member 51 and the rotary tool 1 can be prevented.

[0061] Also, in a state where the stirring pin 50 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 slide shaft 31 and the bottom portion 22a), the stirring pin 50 is pressed against the workpiece 2, and the load applied by the joining device is applied to the stirring pin 50 via the first regulating member 100, so that the stirring pin 50 can be inserted into the workpiece 2.

[0062] Thereafter, in the steady state, the generated reaction force (load) is reduced, the support of the stirring pin 50 by the first regulating member 100 is released, and the stirring pin 50 that is no longer regulated by the first regulating member 100 can move in the axial direction of the rotating shaft 12.

[0063] Also, in order to prevent the rotation tool 1 from becoming large-sized, it is preferable that the outer diameter and free length of the first elastic member 51 be as small (short) as possible. With a constant outer diameter, the shorter the free length of the first elastic member 51, the larger the spring constant, and thus it becomes easier to insert it 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 tends to increase, so the robustness decreases. That is, when the spring constant is increased, the stirring pin 50 is liable to be affected by the first elastic member 51, and thus there is a problem that the operation of the stirring pin 50 is unstable (difficult to control) in the steady state.

[0064] In this regard, according to the present embodiment, even if the spring constant of the first elastic member 51 is not increased, since the first regulating member 100 regulates the movement of the slide shaft 31, a force can be transmitted to the stirring pin 50 via the first regulating member 100. Thereby, the stirring pin 50 can be inserted into the relatively hard joined member 2 as well. Further, since the spring constant of the first elastic member 51 does not need to be increased due to the provision of the first regulating member 100, the degree of freedom in the design of the first elastic member 51 is increased, the robustness in the steady state can be enhanced, and the stirring pin 50 can be stably controlled.

[0065] The main body portion 10 further includes a cylindrical holder 21 and a slide shaft 31 that is slidably accommodated in the central portion of the holder 21 in the rotational axis direction and rotates synchronously with the holder 21, and the assembly 70 is provided at the tip of the slide shaft 31. Thereby, while transmitting the rotational force from the main body portion 10 to the assembly 70, the assembly 70 can slide in the axial direction of the rotating shaft.

[0066] In the rotary tool 1, the first elastic member 51 is housed inside the holder 21 and is disposed between the base end portion 31b of the slide shaft 31 and the bottom portion 22a of the holder 21. Thereby, the force received by the first elastic member 51 from the stirring pin 50 side can be received by the bottom portion 22a of the holder 21. Therefore, even when the slide shaft 31 moves, since the first elastic member 51 stably biases the stirring pin 50 toward the tip side, the accuracy of load control of the stirring pin 50 can be enhanced.

[0067] Further, a key groove 23 is formed in the holder 21, and a key 32 is formed in the slide shaft 31. Thereby, the slide shaft 31 and the assembly 70 are allowed to move in the axial direction in a stable state while rotating synchronously with the rotation of the holder 21. Therefore, the operations of the stirring pin 50 and the shoulder 60 become even more stable.

[0068] A bearing 63 is interposed between the shoulder 60 and the stirring pin 50. Therefore, the shoulder 60 and the stirring pin 50 can relatively rotate in a stable state.

[0069] Further, since the rotary tool 1 includes a holding portion 80 that holds the shoulder 60 in a non-rotating state, it becomes easier to hold the shoulder 60 in a non-rotating state, and the finish of the surface of the workpiece 2 after friction stir welding becomes even better.

[0070] In the rotary tool 1, the first elastic member 51 is 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 51.

[0071] The joining device 3 includes a rotary tool 1, power means, and position control means. Then, the position control means moves the rotary tool 1 to a predetermined height position with respect to the workpiece 2, presses the shoulder 60 against the workpiece 2, inserts the stirring pin 50 into the workpiece 2, and performs friction stir welding on the workpiece 2. According to the joining device 3, by utilizing the elasticity of the first elastic member 51, friction stir welding can be performed while performing load control for controlling the insertion depth of the stirring pin 50 into the workpiece 2 and the contact of the shoulder 60 with the workpiece 2. Further, the shoulder 60 presses down on the metal material that has overflowed from the insertion site of the stirring pin 50 due to the friction stirring by the stirring pin 50, thereby reducing the generation of burrs and improving the surface finish after friction stir welding. Therefore, even when using a machining center, pseudo load control becomes possible and the surface finish after friction stir welding improves.

[0072] In this joining method, the rotary tool 1 is moved to a predetermined height position with respect to the workpiece 2, the shoulder 60 is pressed against the workpiece 2, and the rotating stirring pin 50 is inserted into the workpiece 2 to perform friction stir welding on the workpiece 2. According to this joining method, by utilizing the elasticity of the first elastic member 51, friction stir welding can be performed while performing load control for controlling the insertion depth of the stirring pin 50 into the workpiece 2 and the contact of the shoulder 60 with the workpiece 2. Further, the shoulder 60 presses down on the metal material that has overflowed from the insertion site of the stirring pin 50 due to the friction stirring by the stirring pin 50, thereby reducing the generation of burrs and improving the surface finish after friction stir welding.

[0073] 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, friction stir joining can be performed while performing load control using the first elastic member 51. Further, according to the rotary tool 1, the joining device 3, and the joining method, by using the first restricting member 100, damage to the first elastic member 51 can be prevented even for a relatively hard workpiece, and the stirring pin can be inserted while performing load control and friction stir joining can be performed.

[0074] [2. First Modified Example] Next, a first modified example of the first embodiment will be described with reference to FIG. 7. As shown in FIG. 7, the holding portion 85 according to the first modified example has a rectangular outer shape of a shoulder 65 provided below the flange portion 53, and a guide member 86 is provided along the movement locus of the rotary tool 1A. The guide member 86 is formed of a long member and is disposed so as to sandwich the shoulder 65 from both sides. The guide member 86 is a holding portion provided in the joining device 3. The shoulder 65 having such a configuration moves along the movement locus without rotating while the outer peripheral surface slides on the side surface of the guide member 86. Inside the shoulder 65, a stirring pin 50 and a bearing 63 are inserted in the same manner as the shoulder 60 in FIG. 1. Since the 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.

[0075] [3. Second Modified Example] Next, a second modified example of the first embodiment will be described with reference to FIG. 8. In the above embodiment, the lower end surface of the shoulder 60 is immovable in the axial direction of the rotation axis with respect to the stirring pin 50, but the shoulder 90 according to the second modified example has a configuration in which the lower end surface of the shoulder 90 is movable in the axial direction. Specifically, the shoulder 90 of the rotary tool 1B has a first member 91, a second member 92, a second elastic member 99, and a second restricting member 110. Further, the stirring pin 50 and the shoulder 90 are integrated to form an assembly 75 that moves together in the axial direction of the rotation axis 12.

[0076] The first member 91 is a part provided so as to be rotatable relative to the stirring pin 50 and is formed of, for example, tool steel. The first member 91 has a cylindrical shape and is coaxially arranged so as to surround the stirring pin 50. The stirring pin 50 is inserted into the hollow portion 93 of the first member 91. The base end portion (the upper end portion in FIG. 8) of the hollow portion 93 is open, and a bearing 63 is interposed between the stirring pin 50 and the first member 91. The bearing 63 is arranged so as to surround the stirring pin 50. As a result, the first member 91 is rotatable relative to the stirring pin 50 and immovable relative to the axial direction.

[0077] A protruding portion 94 that protrudes from the intermediate end surface 91a of the first member 91 toward the tip side is formed at the tip portion (the lower end portion in FIG. 8) of the first member 91. The protruding portion 94 has a cylindrical shape, and the stirring pin 50 is inserted therethrough. The protruding portion 94 is a member for connecting the second member 92. A key 96 that protrudes outward from the outer peripheral surface is provided at the tip portion of the protruding portion 94. The key 96 is inserted into a key groove 97 of the second member 92 described later. The key 96 has an oblong shape that is long in the rotational axis direction, is radially arranged at 180° intervals in the circumferential direction, and is formed at two locations. Note that the shape of the key 96 is not limited to the oblong shape, and may be other shapes such as circular, elliptical, oblong, rectangular, etc., as long as it has the same width dimension as the key groove 97.

[0078] The second member 92 is a part that presses the joined member 2 in a state of contacting the joined member 2. The second member 92 is attached to the protruding portion 94, rotates synchronously with the first member 91, and is a part that is movable relative to the first member 91 in the axial direction of the rotation axis 12. The second member 92 is formed of, for example, tool steel. The second member 92 has a cylindrical shape and is coaxially arranged so as to surround the stirring pin 50. The stirring pin 50 is inserted into the hollow portion 95 of the second member 92. The base end portion (the upper end portion in FIG. 8) of the hollow portion 95 is open, and the tip portion of the protruding portion 94 is inserted therein.

[0079] A key groove 97 is formed in the hollow portion 95. The key groove 97 is formed in an elongated oval shape along the axial direction of the rotating shaft 12 (the vertical direction in FIG. 8), and is formed in a groove shape on the inner peripheral surface of the hollow portion 95. The key groove 97 is formed at two positions corresponding to the key 96 of the protruding portion 94. The axial length of the key groove 97 is longer than the axial length of the key 96, and the second member 92 can move axially with respect to the first member 91. The width dimension of the key groove 97 is equivalent to the width dimension of the key 96, and the second member 92 cannot rotate relative to the first member 91. When the key 96 is located on the proximal end side of the key groove 97, the tip end portion (tip end surface) of the second member 92 is at the same height as the proximal end portion of the tapered surface of the tip end portion 52 of the stirring pin 50. That is, the tip end portion 52 of the stirring pin 50 protrudes from the tip end surface of the second member 92 toward the tip end side. The second member 92 moves toward the first member 91 from the said position, and the axial length of the shoulder 90 becomes short.

[0080] The second elastic member 99 is a portion that biases a part of the second member 92, which is a part of the shoulder 90, toward the tip end side of the stirring pin 50 with respect to the axial direction of the rotating shaft 12. The second elastic member 99 is constituted by, for example, a coil spring, and is arranged so as to surround the outer peripheral surface of the protruding portion 94. The second elastic member 99 is mounted between the intermediate end surface 91a of the first member 91 and the proximal end portion (proximal end surface) 92b of the second member 92. The second elastic member 99 can bias the second member 92 toward the tip end side with respect to the force received from the second member 92.

[0081] The elasticity of the second elastic member 99 is set such that when the stirring pin 50 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 second member 92 is displaced within a predetermined range with respect to the entire movable range of the second member 92 by the elastic member so as to press the joined member 2.

[0082] For example, when the second elastic member 99 is a coil spring and the load applied to the second elastic member 99 is inserted in the range of 50 kg to 2 t, the amount of deflection of the second elastic member 99 is in the range of 0 to 30% with respect to the free length of the second elastic member 99, and the second member 92 is set to press the joined member 2. Thereby, in a state where the second member 92 is in contact with the joined member 2, the second member 92 can easily hold down the joined member 2 without being inserted into the joined member 2. The second elastic member 99 is more easily deformed than the first elastic member 51.

[0083] Note that the second elastic member 99 is not limited to a coil spring like the first elastic member 51, 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 99 may be a fluid spring using pneumatic pressure, gas pressure, or hydraulic pressure, or a magnetic spring using magnetic force or electromagnetic force.

[0084] The second elastic member 99 may be set so as to satisfy the relationship between the amount of deformation and the elastic modulus that allows the shoulder 90 pressed against the joined member 2 to 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, considering the joining conditions. Examples of the joining conditions that affect the setting of the second elastic member 99 include conditions of the joined member such as the material of the joined member 2 and the shape of the joining portion, and joining modes such as the insertion depth of the stirring pin 50, the shape of the rotary tool 1B, the rotation speed, and the moving speed. Note that the shoulder 90 only needs to be in contact with at least a part of the joined member 2, and a slight space may be generated between the shoulder 90 and the joined member 2 according to the surface shape of the joined member 2, but it is preferable to be in contact with the joined member 2 without a gap so as to hold down the metal material overflowed by friction stir joining and prevent the generation of burrs. Further, the shoulder 90 may be slightly inserted into the joined member 2, but it is preferable not to be deeply inserted into the joined member 2 to such an extent that no recess is generated due to the contact between the joined member 2 and the shoulder 90 after joining.

[0085] As shown in FIG. 8, the second restricting member 110 is a member that restricts the second member 92 from moving beyond a predetermined range toward the proximal end side of the rotation shaft 12 with respect to the first member 91. In the present embodiment, the second restricting member 110 is fixed to the proximal end portion 92b of the second member 92. Although the shape of the second restricting member 110 is not particularly limited, it has a cylindrical shape in the present embodiment. 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. The second restricting member 110 restricts the axial movement of the second member 92 so that the amount of deformation generated in the second elastic member 99 does not exceed the maximum deflection amount (maximum allowable amount) of the second elastic member 99 as the second member 92 moves.

[0086] According to such a configuration, relative movement between the tip surface of the shoulder 90 and the stirring pin 50 becomes possible, and load control of the shoulder 90 can be achieved by the second elastic member 99. Therefore, the accuracy of load control of the shoulder 90 can be further enhanced. Further, in the shoulder 90 of this modification, a holding portion (not shown) may be fixed to the outer peripheral surface of the first member 91, and the shoulder 90 and the second member 92 may be held in a non-rotating state by the holding portion.

[0087] Further, the rotary tool 1B according to the present embodiment includes a second restricting member 110 that restricts the movement of the second member 92 toward the proximal end side with respect to the first member 91. More specifically, when the second elastic member 99 is pushed through the second member 92 by the workpiece 2 to be joined, the second restricting member 110 abuts against the intermediate end surface 91a of the first member 91 before the amount of deflection of the second elastic member 99 reaches the maximum deflection amount. Thereby, at the time of insertion of the rotary tool 1B when the generated reaction force (load) becomes maximum, or at a position where the shape of the workpiece 2 to be joined changes greatly, the amount of deformation generated in the second elastic member 99 is within a range not exceeding the maximum deflection amount of the second elastic member 99, and the movement of the second member 92 is restricted by the second restricting member 110. Therefore, even when the workpiece 2 to be joined is relatively hard and requires a large load, it is possible to prevent the second elastic member 99 from deforming beyond the limit. As a result, it is possible to press against the relatively hard workpiece 2 to be joined with the shoulder 90 and to prevent damage to the rotary tool 1B.

[0088] Further, in a state where the second member 92 (shoulder 90) 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 between the first member 91 and the second member 92), when the second member 92 is pressed against the joined member 2 and the load applied by the joining device is applied to the second member 92 via the second regulating member 110, the joined member 2 can be pressed by the second member 92.

[0089] After that, in the steady state, the generated reaction force (load) is reduced, the support of the second member 92 by the second regulating member 110 is released, and the second member 92 that is no longer regulated by the second regulating member 110 can move in the axial direction. At this time, since the second member 92 is biased toward the tip side by the second elastic member 99, the joined member 2 is pressed by the second member 92. That is, by setting the second elastic member 99 in consideration of joining conditions such as the joined member 2 and the joining mode, pseudo load control using the second elastic member 99 can be performed to press the second member 92 with a desired stress.

[0090] Also, in order to prevent the rotation tool 1B from becoming large, it is preferable that the outer diameter and free length of the second elastic member 99 are as small (short) as possible. With a constant outer diameter, the shorter the free length of the second elastic member 99, the larger the spring constant, 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 second member 92 is easily affected by the second elastic member 99, and there is a problem that the operation of the second member 92 is not stable (difficult to control) in the steady state.

[0091] In this regard, according to the present embodiment, even if the spring constant of the second elastic member 99 is not increased, since the second restricting member 110 restricts the movement of the second member 92, a force can be transmitted to the second member 92 via the second restricting member 110. As a result, the second member 92 can also be pressed against the relatively hard joined member 2. Further, since the spring constant of the second elastic member 99 does not need to be increased by providing the second restricting member 110, the degree of freedom in the design of the second elastic member 99 is increased, the robustness in the steady state can be enhanced, and the second member 92 can be stably controlled.

[0092] Note that the second modification example is not limited to the above-described configuration and can be appropriately changed. For example, in the second modification example, the second restricting member 110 is provided on the second member 92, but the second restricting member 110 may be provided on the intermediate end surface 91a of the first member 91. By the second restricting member 110 and the base end portion 92b of the second member 92 coming into contact with each other before the second elastic member 99 reaches the maximum deflection amount, it is possible to prevent the second elastic member 99 from deforming beyond the maximum deflection amount. Further, the second restricting member 110 may be formed in a ring shape and loosely fitted between the first member 91 and the second member 92.

[0093] Also, in the second modification example, the second restricting member 110 is provided on the second member 92, but the second restricting member 110 may be provided on the bottom portion 95a of the hollow portion 95 of the second member 92. By the second restricting member 110 and the protruding portion 94 coming into contact with each other before the second elastic member 99 reaches the maximum deflection amount, it is possible to prevent the second elastic member 99 from deforming beyond the maximum deflection amount.

[0094] Also, in the second modification example, the second restricting member 110 is provided on the second member 92, but the second restricting member 110 may be provided at the end portion (lower end portion) of the protruding portion 94. By the second restricting portion 110 and the bottom portion 95a of the hollow portion 95 coming into contact with each other before the second elastic member 99 reaches the maximum deflection amount, it is possible to prevent the second elastic member 99 from deforming beyond the maximum deflection amount.

[0095] In the second modification, the second restricting member 110 is provided on the second member 92. However, the second restricting member 110 may be provided on the outer peripheral surface of the distal end side of the protruding portion 94. Further, a groove portion that allows axial movement of the second restricting member 110 may be provided on the inner peripheral surface of the second member 92. Before the second elastic member 99 reaches the maximum deflection amount, the second restricting member 110 abuts against the groove wall of the groove portion, thereby preventing the second elastic member 99 from deforming beyond the maximum deflection amount. Note that the groove portion of the second member 92 and the second elastic member 99 may be realized by the key groove 97 and the key 96.

[0096] In the second modification, the second restricting member 110 is provided on the second member 92. However, the second restricting member 110 may be provided on the outer peripheral surface (side surface portion) of the proximal end side of the protruding portion 94. Before the second elastic member 99 reaches the maximum deflection amount, the second restricting member 110 abuts against the proximal end portion 92b of the second member 92, thereby preventing the second elastic member 99 from deforming beyond the maximum deflection amount.

[0097] [4. Second Embodiment] Next, with reference to FIG. 9, the rotary tool 1C according to the second embodiment will be described. The rotary tool 1C according to the second embodiment includes a main body portion 10 having a holder 21 and a slide shaft 31, a stirring pin 50, a first elastic member 51, and a first restricting member 100C. 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.

[0098] The first restricting member (first proximal end side fixing restricting member) 100C according to the present embodiment is fixedly provided on the bottom portion 22a of the holder 21. That is, the proximal end portion 100Cb of the first restricting member 100C and the bottom portion 22a are always connected. Although specific illustration is omitted, as shown in FIG. 2, before the first elastic member 51 reaches the maximum deflection amount, the distal end portion 100Ca of the first restricting member 100C abuts against the proximal end portion 31b of the slide shaft 31, and the movement of the slide shaft 31 and the stirring pin 50 (assembly 70) toward the proximal end side can be restricted.

[0099] Also according to this embodiment, effects substantially equivalent to those of the first embodiment can be achieved. Further, according to this embodiment, since the first restricting member 100C is provided at the bottom 22a of the holder 21, it is possible to avoid the restricting member from moving freely inside the holder 21 and coming into contact with the first elastic member 51. In addition, since the first restricting member 100C can be fixed in place, the tip 100Ca of the first restricting member 100C and the base end 31b of the slide shaft 31 can be brought into contact at a fixed position, and the reaction force generated with the insertion of the rotary tool 1C can be received at a predetermined position to enable stable operation.

[0100] [5. Third Embodiment] Next, with reference to FIG. 10, the rotary tool 1D according to the third embodiment will be described. The rotary tool 1D according to the third embodiment includes a main body 10 having a holder 21 and a slide shaft 31, a stirring pin 50, a first elastic member 51, and a first restricting member 100D. Since the basic configuration is the same as that of the above-described embodiment, the same reference numerals are used and the description thereof is omitted.

[0101] The first restricting member (first tip-side fixed restricting member) 100D according to this embodiment is provided fixed to the slide shaft 31. That is, the tip 100Da of the first restricting member 100D and the base end 31b of the slide shaft 31 are always connected. Although specific illustration is omitted, as shown in FIG. 2, until the first elastic member 51 reaches the maximum deflection amount, the base end 100Db of the first restricting member 100D abuts against the bottom 22a of the holder 21, and the movement of the slide shaft 31 and the base end side of the stirring pin 50 (assembly 70) can be restricted.

[0102] Also according to this embodiment, effects substantially equivalent to those of the first embodiment can be achieved. Further, according to this embodiment, since the first regulating member 100D is provided on the slide shaft 31, it is possible to avoid the regulating member from contacting the first elastic member 51 by floating inside the holder 21. In addition, since the first regulating member 100D can be fixed in a fixed position, the base end portion 100Db of the first regulating member 100D and the bottom portion 24 of the 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 1D can be received at a predetermined position to perform a stable operation.

[0103] [6. Fourth Embodiment] Next, with reference to FIGS. 11 and 12, the rotary tool 1E according to the fourth embodiment will be described. The rotary tool 1E according to the fourth embodiment includes a main body portion 10 having a holder 21 and a slide shaft 31, a stirring pin 50, a first elastic member 51, and a first regulating member 100E. 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.

[0104] The first regulating member (first intermediate regulating member) 100E according to this embodiment is fixedly provided on the outer peripheral surface (side surface portion) of the slide shaft 31. The first regulating member 100E is a plate-like member that projects radially outward in a direction perpendicular to the outer peripheral surface of the slide shaft 31. In particular, the first regulating member 100E is provided on the outer peripheral surface on the proximal end side in the axial direction of the slide shaft 31. The first regulating member 100E may be singular or plural. The first regulating member 100E is formed to move axially along with the movement of the slide shaft 31 within a through hole M that penetrates the holder 21 in the radially outward direction. As shown in FIG. 12, until the first elastic member 51 reaches the maximum deflection amount, the first regulating member 100E and the hole wall (intermediate portion of the holder) Ma on the proximal end side of the through hole M come into contact with each other, and the movement of the slide shaft 31 and the stirring pin 50 (assembly 70) toward the proximal end side can be regulated.

[0105] In the present embodiment, the through-hole M of the holder 21 is regarded as the "intermediate portion". However, other portions of the holder 21 may be set as the "intermediate portion", and the intermediate portion and the first restricting member 100E may be brought into contact with each other. Further, instead of the through-hole M, a groove portion may be provided so that the first restricting member 100E moves within the groove portion. Further, the through-hole M and the first restricting member 100E may be realized by the key groove 23 and the key 32.

[0106] Also according to the present embodiment, an effect substantially equivalent to that of the first embodiment can be achieved. Further, according to the present embodiment, since the first restricting member 100E is provided on the outer peripheral surface of the slide shaft 31, interference with the first elastic member 51 housed inside the holder 21 can be avoided. For this reason, for example, even when the restricting member cannot be housed inside the holder 21 together with the elastic member due to the influence of the structure, shape, operation, or function of the elastic member, the movement of the assembly 70 can be restricted by the first restricting member 100E provided on the outer peripheral surface. Therefore, the degree of freedom in design can be increased.

[0107] [7. Fifth Embodiment] Next, the rotary tool 1F according to the fifth embodiment will be described with reference to FIGS. 13 and 14. The rotary tool 1F according to the fifth embodiment includes a main body portion 10 having a holder 21 and a slide shaft 31, a stirring pin 50, a first elastic member 51, and a first restricting member 100F. 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.

[0108] The first restricting member (first tip-side restricting member) 100F according to the present embodiment is fixedly provided on the outer peripheral surface (side surface portion) of the slide shaft 31. In particular, the first restricting member 100F is provided on the outer peripheral surface on the tip side of the slide shaft 31. The first restricting member 100F is a plate-like member that projects perpendicularly in the radially outward direction from the outer peripheral surface of the slide shaft 31. The first restricting member 100F may be singular or a plurality may be formed. As shown in FIG. 14, until the first elastic member 51 reaches the maximum deflection amount, the first restricting member 100F abuts against the tip portion 21a of the holder 21, and the movement of the slide shaft 31 and the base end side of the stirring pin 50 (assembly 70) can be restricted.

[0109] Also according to the present embodiment, substantially the same effects as those of the first embodiment can be achieved. Furthermore, according to the present embodiment, since the first restricting member 100F is provided on the outer peripheral surface of the slide shaft 31, interference with the first elastic member 51 housed inside the holder 21 can be avoided. For this reason, for example, even when the restricting member cannot be housed inside the holder 21 together with the elastic member due to the influence of the structure, shape, operation, or function of the elastic member, the movement of the assembly 70 can be restricted by the first restricting member 100F provided on the outer peripheral surface. Therefore, the degree of freedom in design can be increased. Also, by the key groove 23 and the key 32, the through hole M and the first restricting member 100E are realized, and according to the present embodiment compared to the case where the first restricting member 100E abuts against the key groove 23, since the first restricting member 100F abuts against the tip portion 21a of the holder 21, it is possible to avoid applying a load to the key groove 23.

[0110] [8. Sixth Embodiment] Next, with reference to FIGS. 15 and 16, the rotary tool 1G according to the fifth embodiment will be described. The rotary tool 1G according to the sixth embodiment includes a main body portion 10 having a holder 21 and a slide shaft 31, a stirring pin 50, a first elastic member 51, and a first restricting member 100G. 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 surface regulating member) 100G according to this embodiment is provided fixed to the tip portion (tip surface) 31a of the slide shaft 31. The first regulating member 100G is a plate-like member that projects perpendicularly in the radially outward direction from the tip portion (tip surface) 31a of the slide shaft 31. The first regulating member 100G projects outside the outer peripheral surface of the slide shaft 31. The first regulating member 100G may be singular or a plurality may be formed. As shown in FIG. 16, until the first elastic member 51 reaches the maximum deflection amount, the first regulating member 100G abuts against the tip portion 21a of the holder 21, and the movement of the slide shaft 31 and the base end side of the stirring pin 50 (assembly 70) can be regulated.

[0112] Also according to this embodiment, an effect substantially equivalent to that of the first embodiment can be achieved. Furthermore, according to this embodiment, since the first regulating member 100G is provided at the tip portion of the slide shaft 31, interference with the first elastic member 51 housed inside the holder 21 can be avoided. For this reason, for example, even when the regulating member cannot be housed inside the holder 21 together with the elastic member due to the influence of the structure, shape, operation, or function of the elastic member, the first regulating member 100G provided at the tip portion can regulate the movement of the assembly 70. Therefore, the degree of freedom in design can be increased. Also, by means of the key groove 23 and the key 32, the through hole M and the first regulating member 100E are realized, and according to this embodiment compared to the case where the first regulating member 100E abuts against the key groove 23, since the first regulating member 100G abuts against the tip portion 21a of the holder 21, it is possible to avoid a load being applied to the key groove 23.

[0113] [9. Seventh Embodiment] Next, with reference to FIGS. 17 and 18, the rotary tool 1H according to the seventh embodiment will be described. The rotary tool 1H according to the seventh embodiment includes a main body portion 10 having a holder 21 and a slide shaft 31, a stirring pin 50, and a first elastic member 51. Since the basic configuration is the same as that of the above-described embodiments, the same reference numerals will be given and the description will be omitted.

[0114] The stirring pin 50 according to this embodiment is composed of a tip portion 52 and a flange portion 53. The flange portion 53 has a larger diameter than the tip portion 52. Also, the outer diameter of the flange portion 53 is larger than the inner diameter of the slide shaft 31. Further, the outer diameter of the flange portion 53 is larger than the inner diameter of the storage recess 22 of the holder 21. As shown in FIG. 18, until the first elastic member 51 reaches the maximum deflection amount, the flange portion 53 of the stirring pin 50 abuts against the tip portion 21a of the holder 21, and the movement of the base end side of the slide shaft 31 and the stirring pin 50 (assembly 70) can be restricted. That is, in this embodiment, the stirring pin 50 itself serves as a restricting member.

[0115] Also according to this embodiment, an effect substantially equivalent to that of the first embodiment can be achieved. Further, according to this embodiment, since the stirring pin 50 functions as a restricting member, interference with the first elastic member 51 housed inside the holder 21 can be avoided. For this reason, for example, even when the restricting member cannot be housed inside the holder 21 together with the elastic member due to the influence of the structure, shape, operation, or function of the elastic member, the movement of the stirring pin 50 itself and the assembly 70 can be restricted by the stirring pin 50. Therefore, the degree of freedom in design can be increased.

[0116] [10. 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 spirit of the present invention. In the above embodiment, the key groove 23 is formed in the holder 21 and the key 32 is formed in the slide shaft 31, but the present invention is not limited to this. A key may be formed in the holder 21 and a key groove may be formed in the slide shaft 31.

[0117] In the above-described embodiment, the rotating tool 1 is provided with a holding portion 80 fixed to the shoulder 60, and an example is shown in which this holding portion is connected to a joining device to hold the shoulder 60 in a non-rotating state. However, the present invention is not limited to this. The joining device 3 may be provided with 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 shoulder 60 of the rotating tool 1 to hold the shoulder 60 in a non-rotating state. This second holding portion is included in the joining device 3. Further, the rotating tool 1 is provided with a rod-shaped arm member fixed to the shoulder 60 as a holding portion 80, and the joining device 3 is provided with a rod-shaped arm member fixed to the fixing system of the joining device 3 as a second holding portion. By connecting both holding portions to each other, the shoulder 60 may be held in a non-rotating state. This holding portion is included in the rotating tool 1 and the joining device 3. Thus, a holding portion included in the rotating tool 1 and a second holding portion included in the joining device 3 and operating in cooperation with the holding portion included in the rotating tool 1 may be provided simultaneously. As described above, by providing the joining device 3 with a second holding portion that holds the shoulder 60 in a non-rotating state, it becomes easier to hold the shoulder 60 in a non-rotating state, and the finish of the surface of the joined member 2 after friction stir joining becomes even better.

[0118] Also, in the above-described embodiment, the first elastic member 51 is disposed between the slide shaft 31 and the bottom portion 22a of the storage recess 22. However, it may be disposed anywhere as long as it is a position that biases the assembly 70 toward the tip side. Further, the arrangement of the regulating member may be changed according to the arrangement of the first elastic member 51. For example, the first elastic member 51 may be disposed on the outer periphery of the slide shaft 31 between the holder 211 and the flange portion 53. In such a case, the first elastic member 51 is located near the intermediate portion between the slide shaft 31 and the stirring pin 50, and the first elastic member 51 acts evenly in the circumferential direction of the slide shaft 31. Therefore, even when the slide shaft 31 moves, the first elastic member 51 stably biases the assembly 70 toward the tip side. Therefore, the accuracy of load control of the stirring pin 50 and the shoulder 60 can be improved.

[0119] In the second modification example, the case where the tip 52 of the stirring pin 50 protrudes below the tip (tip surface) 92a of the second member 92 is illustrated, but the present invention is not limited thereto. In a state where the rotary tool 1B is not in contact with the member to be joined 2, the tip 92a of the second member 92 may protrude below the tip 52 of the stirring pin 50. Thereby, when the rotary tool 1B is pulled out from the member to be joined 2, when the rotary tool 1B is moved away from the member to be joined 2, the stirring pin 50 detaches from the member to be joined 2 before the second member 92 while the second member 92 is pressing the member to be joined 2. At this time, while maintaining the state where the second member 92 presses the member to be joined 2, by pulling out the stirring pin 50, the second member 92 can hold down the metal material that has flowed and overflowed due to the insertion of the stirring pin 50. Therefore, it becomes easier to fill the extraction hole generated when pulling out the stirring pin 50 with the metal material held down by the second member 92. In particular, when performing friction stir welding at a spot where joining is performed at the position where the rotary tool 1B is inserted during friction stir welding and the rotary tool 1B is pulled out without being moved from the insertion position, it becomes easier to prevent the formation of an extraction hole.

[0120] In the above embodiment, the case where the first restricting member 100 is columnar and the first restricting member 100 is disposed in the hollow portion of the first elastic member 51 is illustrated and described. The first restricting member may be a cylindrical shape having an inner diameter larger than the outer diameter of the first elastic member 51. In this case, the first elastic member 51 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 51.

Description of Reference Numerals

[0121] 1 Rotary tool 2 Member to be joined 3 Joining device 10 Body portion 11 Fixing portion 12 Rotation shaft 21 Holder 23 Key groove 31 Slide shaft 32 Key 50 Stirring pin 51 First elastic member 60 Shoulder 61 Hollow part 63 Bearing 65 Shoulder 70 Assembly 80, 85 Holding part 90 Shoulder 99 Second elastic member 100 First regulating member 110 Second regulating 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 rotary shaft for transmitting a rotational force from the joining device, rotatably disposed on the main body part so as to receive a rotational force from the main body part and movable in the axial direction of the rotary shaft, a stirring pin inserted into the joined member to perform friction stirring on the joined member, and a shoulder provided on the main body part so as to be configured separately from the stirring pin, not receiving a rotational force from the main body part, and movable in the axial direction of the rotary shaft, and pressing the joined member in a state of being in contact with the joined member, the stirring pin and the shoulder are relatively rotatable and are attached so as to move integrally in the axial direction of the rotary shaft to form an assembly, a first elastic member for biasing the assembly toward the tip side of the stirring pin in the axial direction of the rotary shaft, and a first restricting member for restricting the assembly from moving toward the proximal end side in the axial direction of the rotary shaft, the first restricting member restricts the movement of the assembly so that the amount of deformation generated in the first elastic member as the assembly moves does not exceed the maximum allowable capacity of the first elastic member, A rotary tool characterized by this.

2. The main body part further has a hollow cylindrical holder attached to the rotary shaft, and a slide shaft slidably accommodated in the central part of the holder in the rotary shaft direction and rotating synchronously with the holder, the assembly is provided at the tip of the slide shaft, the slide shaft is biased toward the tip side of the assembly via the first elastic member, the first restricting member restricts the slide shaft from moving toward the proximal end side in the axial direction of the rotary shaft, The rotary tool according to Claim 1.

3. A second elastic member that biases the shoulder toward the tip side of the stirring pin with respect to the axial direction of the rotating shaft, and a second restricting member that restricts the shoulder from moving toward the proximal end side in the axial direction of the rotating shaft, and further includes 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. The rotary tool according to claim 1 or 2.

4. The first restricting member is provided in the holder, as the slide shaft moves, the movement of the slide shaft is restricted by contact between the proximal end portion of the slide shaft and the bottom portion on the proximal end side of the holder and the first restricting member. The rotary tool according to claim 2.

5. The first restricting member is provided at the bottom portion on the proximal end side of the holder, as the slide shaft moves, the movement of the slide shaft is restricted by contact between the proximal end portion of the slide shaft and the first restricting member. The rotary tool according to claim 2.

6. The first restricting member is provided at the proximal end portion of the slide shaft, as the slide shaft moves, the movement of the slide shaft is restricted by contact between the bottom portion on the proximal end side of the holder and the first restricting member. The rotary tool according to claim 2.

7. The first restricting member is provided on the outer peripheral surface of the slide shaft, as the slide shaft moves, the movement of the slide shaft is restricted by contact between the first restricting member and the middle portion of the holder. The rotary tool according to claim 2.

8. The first restricting member is provided on the outer peripheral surface of the slide shaft, As the slide shaft moves, the first regulating member comes into contact with the tip of the holder, thereby regulating the movement of the slide shaft. The rotary tool according to claim 2.

9. The first regulating member is provided at the tip of the slide shaft. As the slide shaft moves, the first regulating member comes into contact with the tip of the holder, thereby regulating the movement of the slide shaft. The rotary tool according to claim 2.

10. The stirring pin is the first regulating member. As the slide shaft moves, the stirring pin comes into contact with the tip of the holder, thereby regulating the movement of the slide shaft. The rotary tool according to claim 2.

11. A joining device comprising the rotary tool according to any one of claims 1 to 10, 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, The position control means moves the rotary tool to a predetermined height position with respect to the member to be joined, inserts the stirring pin into the member to be joined, and performs friction stir joining on the member to be joined. A joining device characterized by the above.

12. Moving the rotary tool according to any one of claims 1 to 10 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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