Rotation 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 has: a body part 10 having a fixing part 11 and a rotation axis 12; a stirring member 50 with a stirring pin 51 performing friction stir welding of a member to be welded, which is disposed in a rotatable manner by receiving rotation force from the rotation axis 12, and also disposed on the body part 10 in a movable manner in an axial direction of the rotation axis 12; an elastic member 70 which energizes the stirring member 50 toward a tip side in the axial direction of the rotation axis 12; and a regulation member 100 which regulates movement of the stirring member 50 to a base end side in the axial direction of the rotation axis 12. The regulation member 100 regulates movement of the stirring member 50 so that a deformation quantity generated in the elastic member 70 with movement of the stirring member may not exceed a maximum allowable quantity of the elastic member 70.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a rotary tool, a welding apparatus, and a welding method used in friction stir welding. [Background technology]

[0002] Known welding devices for performing friction stir welding include those that perform load control and those that perform position control in order to control the amount of thrust of a rotary tool into workpieces to be welded. Load control is mainly used in welding devices that use a robot (robot arm), and position control is mainly used in welding devices that use a machining center (MC).

[0003] An example of a joining device that controls load is disclosed in Patent Document 1. The joining device of Patent Document 1 controls the press-in depth of a shoulder member or a pin member into a workpiece to obtain good joining quality with suitable accuracy according to the joining conditions. In order to control the press-in depth, the joining device controls the relative position of the pin member with respect to the shoulder member based on a press-in reference point set by a press-in reference point setting unit. In order to perform the above control, the joining device includes a pressing force detection unit, a pressure reference point setting unit, a tool drive control unit, and the like. The tool drive unit includes a rotation drive unit, a pin drive unit, a shoulder drive unit, and a clamp drive unit (elastic member: coil spring), and the like. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2012-196681 A Summary of the Invention [Problem to be solved by the invention]

[0005] The welding device of Patent Document 1 has a complex structure and is expensive because it controls the load. Therefore, in recent years, there has been a demand for a rotary tool that can be attached to a relatively inexpensive MC that can only control the position and that can control the load.

[0006] From this viewpoint, an object of the present invention is to provide a rotary tool, a welding device, and a welding method that enable load control in a state where the rotary tool is mounted on a machining center. [Means for solving the problem]

[0007] To solve the above-mentioned problem, the present invention provides a rotary tool used in a welding device for friction stir welding of workpieces, the rotary tool comprising: a main body having a fixing portion attached and fixed to the welding device and a rotating shaft for transmitting a rotational force from the welding device; a stirring member having a stirring pin inserted into the workpieces to perform friction stirring on the workpieces, the stirring member being rotatably provided by receiving a rotational force from the rotating shaft and being movable in the axial direction of the rotating shaft; an elastic member for biasing the stirring member toward a tip side in the axial direction of the rotating shaft; and a regulating member for regulating the stirring member from moving toward a base end side in the axial direction of the rotating shaft, the regulating member regulating the movement of the stirring member such that the amount of deformation generated in the elastic member due to the movement of the stirring member does not exceed a maximum allowable amount of the elastic member. It is characterized by:

[0008] Furthermore, it is preferable that the main body further has a hollow cylindrical holder attached to the rotating shaft, and a slide shaft that is slidably accommodated in the center of the holder in the direction of the rotating shaft and rotates synchronously with the holder, the stirring member is provided at the tip of the slide shaft, the slide shaft is biased toward the tip side of the stirring member via the elastic member, and the regulating member moves the slide shaft toward the base end side in the axial direction of the rotating shaft.

[0009] It is also preferable that the regulating member is provided within the holder, and as the slide shaft moves, the regulating member comes into contact with the base end of the slide shaft and the bottom of the base end side of the holder, thereby regulating the movement of the slide shaft.

[0010] It is also preferable that the regulating member is provided at the bottom of the base end side of the holder, and that as the slide shaft moves, the base end of the slide shaft comes into contact with the regulating member, thereby regulating the movement of the slide shaft.

[0011] It is also preferable that the regulating member is provided at the base end of the slide shaft, and as the slide shaft moves, the bottom of the base end side of the holder comes into contact with the regulating member, thereby regulating the movement of the slide shaft.

[0012] It is also preferable that the regulating member is provided on an outer peripheral surface of the slide shaft, and that as the slide shaft moves, the regulating member comes into contact with an intermediate portion of the holder, thereby regulating the movement of the slide shaft.

[0013] It is also preferable that the regulating member is provided on an outer peripheral surface of the slide shaft, and that as the slide shaft moves, the regulating member comes into contact with the tip of the holder, thereby regulating the movement of the slide shaft.

[0014] It is also preferable that the regulating member is provided at the tip of the slide shaft, and that as the slide shaft moves, the regulating member comes into contact with the tip of the holder, thereby regulating the movement of the slide shaft.

[0015] It is also preferable that the stirring member is the regulating member, and that as the slide shaft moves, the stirring member comes into contact with a tip of the holder, thereby regulating the movement of the slide shaft.

[0016] It is also preferable that the stirring member is connected to the slide shaft, has a cylindrical or frustum shape, has a flat or cone-shaped lower end surface, and further has a shoulder whose lower end surface abuts against the joined members, and that the stirring pin hangs down from the lower end surface of the shoulder.

[0017] It is also preferable that the stirring member further has a columnar or frustum-shaped connecting portion connected to the slide shaft, and the stirring pin hangs down from a lower end surface of the connecting portion.

[0018] The present invention also relates to a joining device including a rotary tool as defined in any one of claims 1 to 11, characterized in that the joining device includes a power means for outputting a rotational force to be transmitted to the rotating shaft of the rotary tool, and a position control means for holding the fixed portion of the rotary tool and controlling a position of the rotary tool, wherein the position control means moves the rotary tool to a predetermined height position relative to the workpieces, and inserts the stirring pin into the workpieces to perform friction stir welding of the workpieces.

[0019] Moreover, it is preferable that the rotating tool is a rotating tool as described in claim 10, and that the stirring pin and the shoulder rotating together with the stirring pin are inserted into the workpieces to perform friction stir welding on the workpieces.

[0020] Moreover, it is preferable that the rotation tool is a rotation tool as described in claim 11, and that with the connecting portion spaced apart from the workpieces, only the rotating stirring pin is inserted into the workpieces to perform friction stir welding on the workpieces.

[0021] The present invention is also characterized in that the rotary tool described in any one of claims 1 to 11 is moved to a predetermined height position relative to the workpieces, the stirring pin is inserted into the workpieces, and friction stir welding is performed on the workpieces. Effect of the Invention

[0022] According to the rotary tool, the welding apparatus, and the welding method of the present invention, it is possible to control the load by using the elastic member. Also, according to the rotary tool, the welding apparatus, and the welding method of the present invention, it is possible to insert the stirring pin while using the elastic member, even into the relatively hard workpieces. [Brief description of the drawings]

[0023] [Figure 1] 1 is a partially cross-sectional side view showing a rotary tool according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is a vertical cross-sectional view showing a state in which the rotary tool according to the first embodiment is fully contracted. [Diagram 3] FIG. 2 is a cross-sectional plan view showing the rotary tool according to the first embodiment. [Figure 4] FIG. 2 is a perspective view showing a rotary tool according to the first embodiment. [Diagram 5] FIG. 2 is an exploded perspective view showing the rotary tool according to the first embodiment. [Figure 6] FIG. 2 is a cross-sectional view showing a state during friction stir welding of the rotary tool according to the first embodiment. [Figure 7] 5 is a graph showing time and generated reaction force during friction stir welding of the rotary tool according to the first embodiment. [Figure 8] FIG. 4 is a partially cutaway perspective view showing a rotary tool according to a first modified example of the first embodiment of the present invention. [Figure 9] FIG. 11 is a longitudinal sectional view showing a rotary tool according to a second modified example of the first embodiment of the present invention. [Figure 10] FIG. 11 is a perspective view showing a rotation tool according to a second modified example of the first embodiment of the present invention. [Figure 11] FIG. 4 is a schematic diagram showing a rotation tool according to a second embodiment of the present invention. [Figure 12] FIG. 11 is a schematic diagram showing a state in which the rotation tool according to the second embodiment is fully contracted. [Figure 13] FIG. 11 is a schematic diagram showing a rotation tool according to a third embodiment of the present invention. [Figure 14]FIG. 11 is a schematic diagram showing a state in which the rotation tool according to the third embodiment is fully contracted. [Figure 15] FIG. 11 is a schematic diagram showing a rotation tool according to a fourth embodiment of the present invention. [Figure 16] FIG. 13 is a schematic diagram showing a state in which the rotation tool according to the fourth embodiment is fully contracted. [Figure 17] FIG. 13 is a schematic diagram showing a rotation tool according to a fifth embodiment of the present invention. [Figure 18] FIG. 13 is a schematic diagram showing a state in which the rotation tool according to the fifth embodiment is fully contracted. [Figure 19] FIG. 13 is a schematic diagram showing a rotary tool according to a sixth embodiment of the present invention. [Figure 20] FIG. 13 is a schematic diagram showing a state in which the rotation tool according to the sixth embodiment is fully contracted. [Figure 21] FIG. 13 is a schematic diagram showing a rotary tool according to a seventh embodiment of the present invention. [Figure 22] FIG. 13 is a schematic diagram showing a state in which the rotation tool according to the seventh embodiment is fully contracted. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] The embodiments of the present invention will be described with reference to the drawings as appropriate. The present invention is not limited to the following embodiments. In addition, some or all of the components in the embodiments can be combined as appropriate. Furthermore, the drawings are intended to conceptually explain the present invention, and the dimensions and ratios of each component shown may differ from the actual ones.

[0025] [1. First embodiment] [1-1. Rotation tool] First, the configuration of the rotation tool according to the first embodiment will be described. As shown in Fig. 1 and Fig. 2, the rotation tool 1 according to this embodiment is used in a welding device 3 that performs friction stir welding of workpieces 2 (see Fig. 6), and is inserted into the butt joints of the workpieces 2 while rotating. The rotation tool 1 includes a main body 10, a stirring member 50, an elastic member 70, and a restricting member 100.

[0026] <Main body> The main body 10 is a part fixed to a joining device 3 such as a machining center, and includes a fixed part 11 and a rotating shaft 12. The fixed part 11 is a part attached to and fixed to the joining device 3, and has a cylindrical shape. The fixed part 11 is a chuck mechanism, and can detachably fix the fixed part 11 to the joining device 3 by cooperating with a mating chuck mechanism provided on the joining device 3. The chuck mechanism can be, for example, a groove provided on the fixed part 11 and a claw provided on the joining device 3 that fits into the groove on the fixed part 11 side and clamps it. A rotating shaft 12 is connected to the other end side (lower side in FIG. 1) of the fixed part 11 from 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 a rotational force from the joining device 3 to the stirring member 50, and is connected to a rotating shaft (not shown) of the joining device 3 via the fixed part 11.

[0027] As also shown in FIGS. 3 to 5, the main body 10 further includes a holder 21 and a slide shaft 31.

[0028] <Holder> The holder 21 is attached to the rotating shaft 12, rotates synchronously with the rotating shaft 12, and supports the slide shaft 31 and the stirring member 50. The holder 21 has a bottomed cylindrical shape (hollow tubular shape) having a bottom 24 at the base end (the end on the joining device 3 side: the upper end in FIG. 1), and the internal hollow portion serves as a storage recess 22 into which the slide shaft 31 is inserted. The storage recess 22 has a cylindrical shape and is open at the tip side (the lower end in FIG. 1) in the axial direction of the rotating shaft 12. A key groove 23 is formed in the cylindrical body of the holder 21. The key groove 23 is formed in a long oval shape along the axial direction of the rotating shaft 12 (the up-down direction in FIG. 1), and penetrates from the outer peripheral surface to the inner peripheral surface of the holder 21. The key groove 23 does not have to penetrate the cylindrical body, and may be formed in a groove shape on the inner peripheral surface of the cylindrical body. The key grooves 23 are disposed at 180° intervals in the circumferential direction of the cylindrical body, and are formed in two locations facing each other. Note that the number of key grooves 23 is not limited to two, and may be one, or three or more.

[0029] <Slide shaft> The slide shaft 31 is a part that is stored in the storage recess 22 of the holder 21 so as to be slidable in the rotation axis direction (up and down direction in FIG. 1) and rotates synchronously (co-rotates) with the holder 21. The slide shaft 31 has a cylindrical shape and has an outer diameter that allows it to be stored in the storage recess 22. A key 32 that protrudes outward is provided on the outer circumferential surface of the slide shaft 31. The key 32 is fixed at a position corresponding to the key groove 23 and inserted into the key groove 23. The key 32 has an elliptical shape that is long in the rotation axis direction, has a width dimension equivalent to that of the key groove 23, and has a length dimension shorter than the longitudinal dimension of the key groove 23. In other words, the key 32 fits in the width direction of the key groove 23 and is movable in the longitudinal direction. The shape of the key 32 is not limited to an elliptical shape, and may be other shapes such as a circle, an ellipse, an oblong, or a rectangle as long as it has a width dimension equivalent to that of the key groove 23. An agitating member 50 is integrally provided at the tip end (the end on the side away from the joining device 3: the lower end in FIG. 1) of the slide shaft 31. Therefore, the agitating member 50 is urged 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 urged toward the tip end side by the elastic member 70.

[0030] <Agitating member> The stirring member 50 is provided on the main body 10 so as to be rotatable by receiving a rotational force from the main body 10, and is provided on the main body 10 so as to be movable in the axial direction of the rotating shaft 12. The stirring member 50 includes a stirring pin 51 and a shoulder 61. The stirring member 50 is made of, for example, tool steel. In this embodiment, the stirring pin 51 and the shoulder 61 are integrally formed, and the stirring member 50 is of a conventional type. The stirring member 50 is integrally formed with the slide shaft 31. Therefore, the stirring member 50 rotates synchronously with the slide shaft 31, and moves in the axial direction of the rotating shaft 12 due to the sliding movement of the slide shaft 31.

[0031] The stirring pin 51 is a part that is inserted into the workpieces while rotating, and performs friction stirring on the workpieces. The tip portion 52 (lower end portion in FIG. 1) of the stirring pin 51 tapers toward the tip. The tip of the tip portion 52 of the stirring pin has a flat surface perpendicular to the axial direction. A shoulder 61 is integrally formed at the base end portion of the stirring pin 51. A spiral groove may be provided on the outer circumferential surface of the stirring pin 51.

[0032] The shoulder 61 is a portion that presses the workpieces 2 with its lower end surface in contact with the workpieces 2. The shoulder 61 is formed in a cylindrical shape that expands in diameter from the base end of the stirring pin 51, and has a planar and ring-shaped tip surface (lower end surface). That is, the tip 52 of the stirring pin 51 protrudes toward the tip side from the tip surface of the shoulder 61. In other words, the stirring pin 51 hangs down from the lower end surface of the shoulder 61. The shape of the shoulder 61 is not limited to a cylindrical shape, and may be a frustum shape. In addition, the lower end surface of the shoulder 61 may be planar or may be mortar-shaped. Furthermore, the lower end surface of the shoulder 61 may have an uneven structure. The base end of the shoulder 61 is integrally connected to the slide shaft 31. The shoulder 61 has a larger diameter than the slide shaft 31, and a connecting portion between the shoulder 61 and the slide shaft 31 (a base end portion of the shoulder 61 on the slide shaft 31 side) has a step portion that is ring-shaped in plan view.

[0033] <Elastic material> The elastic member 70 is a part that biases the stirring member 50, which includes the stirring pin 51 and the shoulder 61, toward the tip side in the axial direction of the rotating shaft 12. The elastic member 70 is configured, for example, by a coil spring. The elastic member 70 is housed inside the holder 21 and attached between the base end portion 31b of the slide shaft 31 and the bottom portion 24 on the base end side of the holder 21. The elastic member 70 is configured to bias the stirring member 50 toward the tip side against a force received from the stirring member 50 side.

[0034] The elasticity of the elastic member 70 is set so that when the stirring pin 51 is inserted with a predetermined pushing load into the joined members 2 made of at least one material selected from the group consisting of aluminum, copper, magnesium, and alloys thereof, the stirring pin 51 is displaced and inserted into the joined members 2 within a predetermined range within the entire movable range of the stirring pin 51.

[0035] For example, when the elastic member 70 is a coil spring, and a load of 100 kg to 5 t is applied to the elastic member 70 when it is inserted, the stirring pin 51 and the shoulder 61 are set to be inserted into the workpieces 2 in a state in which the amount of deflection of the elastic member 70 is deformed within a range of 0 to 30% with respect to the free length of the elastic member 70. As a result, when the stirring pin 51 is pressed into the workpieces 2 at a constant height, even if the height of the workpieces 2 changes, the elastic member 70 deforms in accordance with the change in the workpieces 2, making it easier to keep the insertion amount of the stirring pin 51 constant.

[0036] The elastic member 70 is not limited to a coil spring, but may be a metal spring such as a leaf spring or a disc spring, or a polymeric elastic body (elastomer) such as rubber, polymeric resin, sponge-like resin, etc. Furthermore, the elastic member 70 may be a fluid spring using air pressure, gas pressure, or hydraulic pressure, or a magnetic spring using magnetic force or electromagnetic force.

[0037] The elastic member 70 may be set in consideration of the joining conditions so as to satisfy the relationship between the elastic modulus and the deformation amount when the stirring pin 51 is inserted to a predetermined depth. The elastic member 70 may be set in consideration of the joining conditions so as to satisfy the relationship between the elastic modulus and the deformation amount when the shoulder 61 is slightly inserted in contact with the surface of the workpiece 2. Examples of the joining conditions that affect the setting of the elastic member 70 include the conditions of the joining members such as the material of the workpiece 2 and the shape of the joining part, and the joining mode such as the insertion depth of the stirring pin 51, the contact state of the shoulder 61, and the shape, rotation speed, and movement speed of the rotating tool 1.

[0038] <Regulation material> As shown in FIG. 1 and other figures, the restricting member (loose fit restricting member) 100 is a member that restricts the movement of the stirring member 50 toward the base end side of the rotating shaft 12 beyond a predetermined range. In this embodiment, the restricting member 100 is arranged in a loose fit state in the hollow portion of the elastic member 70 inside the holder 21. The restricting member 100 is formed of a relatively hard material such as metal, resin, rubber, etc. so as to be able to withstand the reaction force during friction stir welding. In this embodiment, the restricting member 100 has a cylindrical shape, but may be appropriately formed according to the shape of the arrangement location. The restricting member 100 restricts the movement of the stirring member 50 so that the amount of deformation occurring in the elastic member 70 due to the movement of the stirring member 50 does not exceed the maximum deflection amount (maximum allowable amount) of the elastic member 70.

[0039] For example, the maximum deflection amount of the elastic member 70 according to this embodiment is set when the elastic member 70 is deformed by 30% with respect to the free length. The maximum deflection amount means the maximum compression amount when the elastic force of the elastic member 70 is exerted. If the maximum deflection amount is exceeded, the elastic force of the elastic member 70 will not be exerted as expected, or it may be damaged earlier than expected.

[0040] 2, in this embodiment, when the amount of deflection of the elastic member 70 becomes 30% with respect to the free length of the elastic member 70, the tip end (tip end surface) 100a of the regulating member 100 abuts against the base end 31b of the slide shaft 31, and the base end (base end surface) 100b abuts against the bottom 24. This makes it possible to prevent the elastic member 70 from being deformed beyond the maximum amount of deflection. The maximum amount of deflection of the elastic member 70 can be appropriately set depending on the elastic member 70 and the regulating member 100. The maximum amount of deflection of the elastic member 70 may be, for example, 25%, 20%, 15%, 10%, or 5%.

[0041] In this embodiment, since the elastic member 70 is used, it is defined as the "maximum deflection amount." Also, as described above, for example, when another member (a fluid spring using air pressure, gas pressure, or hydraulic pressure, or a magnetic spring using magnetic force or electromagnetic force) is used as the elastic member, the amount beyond which the elastic force is not exerted or the elastic member is damaged is defined as the "maximum allowable amount."

[0042] In this embodiment, the regulating member 100 is a solid such as a metal, and regulates the movement of the stirring member 50 by contacting it, but the movement of the stirring member 50 may also be regulated in a non-contact manner using, for example, a fluid spring using air pressure, gas pressure or hydraulic pressure, or a magnetic spring using magnetic force or electromagnetic force.

[0043] Furthermore, the shape and arrangement of the regulating member 100 are not limited as long as it regulates the movement of the stirring member 50. For example, the regulating member 100 may be a part of the main body 10 or the stirring member 50 that functions as the regulating member 100, the regulating member 100 may be provided by being integrally formed with the main body 10 or the stirring member 50, or the regulating member 100 may be provided by attaching a separate member to the main body 10 or the stirring member 50.

[0044] [1-2.Joining device] Next, the configuration of a welding device 3 equipped with the rotary tool 1 having the above-mentioned configuration will be described. The welding device 3 includes a power means (not shown) that outputs a rotational force to be transmitted to the rotary shaft 12 of the rotary tool 1, and a position control means (not shown) that holds the fixed part 11 of the rotary tool 1 and controls the position of the rotary tool. The welding device 3 is configured, for example, by a machining center that performs position control, and the position control device is configured by a CPU or the like, and operates the power means to move the rotary tool 1 based on position information input in advance. The power means moves the rotary tool 1 in three axial directions of X, Y and Z.

[0045] [1-3.Joining method] Next, a welding method according to the present invention will be described with reference to Fig. 6. In this welding method, the rotary tool 1 of this embodiment is moved to a predetermined height position relative to the workpieces 2, and the stirring pin 51 and the shoulder 61 are inserted into the workpieces 2 to a predetermined depth, thereby performing friction stir welding on the workpieces 2.

[0046] When the stirring pin 51 is inserted, as the rotating tool 1 is moved closer in the insertion direction toward the workpieces 2, first the tip of the stirring pin 51 comes into contact with the workpieces 2. As the rotating tool 1 is moved even closer to the workpieces 2, the elastic member 70 is compressed, and the stirring pin 51 is inserted into the workpieces 2 while the elastic force of the elastic member 70 urging the stirring member 50 toward the workpieces 2 becomes stronger. As the rotating tool 1 is moved even closer to the workpieces 2, the shoulder 61 comes into contact with the workpieces 2. As the elastic member 70 is compressed, the elastic force of the elastic member 70 urging the stirring member 50 toward the workpieces 2 becomes stronger, and the shoulder 61 is pressed against the workpieces 2. At this time, the elastic member 70 and the joining conditions are set so that the stirring pin 51 is inserted into the workpieces 2 while leaving some reserve force due to deformation of the elastic member 70 so that the deflection amount of the elastic member 70 does not exceed the maximum deflection amount, and the shoulder 61 can be slightly inserted into the workpieces 2. Alternatively, the stirring member 50 is pressed against the workpieces 2 while the movement of the stirring member 50 is restricted by the regulating member 100 so that the deflection amount of the elastic member 70 does not exceed the maximum deflection amount, thereby inserting the stirring pin 51 into the workpieces 2.

[0047] During welding by the rotary tool 1, the stirring pin 51 and shoulder 61 are biased toward the tip side by the elastic member 70. As shown on the left side in Fig. 6, when there is no error in the height of the workpieces 2 with respect to the set value, the tip 52 of the stirring pin 51 is inserted into the workpieces 2 to the desired depth. The shoulder 61 is designed to be slightly inserted into the workpieces 2 while in contact with the workpieces 2.

[0048] Next, a case will be described in which the height of the workpieces 2 becomes slightly higher than the set value due to an error while friction stir welding is being performed, as shown in the center of Fig. 6. Here, if the elastic member 70 were not present and the stirring pin 51 was simply pressed into the workpieces 2, the insertion amount of the stirring pin 51 and shoulder 61 would be greater by the amount that the height of the workpieces 2 becomes higher, compared to a case in which there is no error in the height of the workpieces 2 relative to the set value.

[0049] In contrast, when welding is performed using the rotary tool 1 of this embodiment, the stirring member 50 is pushed up by the upward reaction force from the workpieces 2 due to the increase in the height of the workpieces 2, and the elastic member 70 is compressed by this pushing up, so that the stirring member 50 is pushed down by the downward elastic force from the elastic member 70. The position of the stirring member 50 is changed to a position where the upward reaction force and the downward elastic force caused by such a change in the height of the workpieces 2 are balanced. The elastic member 70 is set so that the insertion amount of the stirring pin 51 and the shoulder 61 at this time is approximately the same as the insertion amount when the height of the workpieces 2 has no error from the set value. If the elastic force of the elastic member 70 is too weak, the upward reaction force caused by the change in the height of the workpieces 2 becomes larger, and the insertion amount becomes smaller. On the other hand, if the elastic force of the elastic member 70 is too strong, the downward elastic force caused by the change in the height of the workpieces 2 becomes larger, and the insertion amount becomes larger. In other words, even if the height of the workpieces 2 fluctuates and becomes higher, in the rotating tool 1, the stirring pin 51 is inserted into the workpieces 2 to the desired depth set in accordance with the set height of the workpieces 2, and the elastic member 70 is set so that the shoulder 61 is slightly inserted into the workpieces 2.

[0050] Furthermore, when the height of the workpieces 2 becomes lower than the set value, the elastic member 70 expands and the stirring member 50 moves down, as shown on the right side of Fig. 6. In this way, even if the height of the workpieces 2 fluctuates and becomes lower, in the rotating tool 1, the stirring pin 51 is inserted into the workpieces 2 at a desired depth set according to the set height of the workpieces 2, and the elastic member 70 is set so that the shoulder 61 is slightly inserted into the workpieces 2.

[0051] As described above, in the rotating tool 1, the stirring pin 51 and the shoulder 61 are inserted to a constant depth into the workpieces 2 by the action of the elastic member 70, so that a plasticized region is formed to a constant depth. Therefore, stable joining quality can be obtained.

[0052] [1-4. Actions and Effects] According to the rotary tool 1, welding device 3, and welding method of the present embodiment, the stirring member 50, which is provided so as to be movable in the axial direction of the rotating shaft 12, is biased toward the tip side by the elastic member 70, so that while the stirring pin 51 is being inserted into the workpieces 2, the stirring pin 51 is inserted to a predetermined depth according to the elasticity of the elastic member 70. By setting the elastic member 70 in consideration of welding conditions such as the welding materials and welding mode, the stirring pin 51 can be inserted to a desired depth. In other words, the rotary tool 1 can perform pseudo load control using the elastic member 70.

[0053] When a rotating 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 rotating tool 1 is constant based on the setting value of the machining center, and the insertion position of the stirring member 50 is approximately constant. In contrast, when the rotating tool 1 of this embodiment is used, even if the support height of the rotating tool 1 by the machining center is constant, the elastic member 70 expands and contracts appropriately in response to fluctuations in the height of the workpieces 2, and the stirring member 50 moves in the axial direction. In this way, by utilizing the elasticity of the elastic member 70, load control is possible, which allows the insertion depth of the stirring pin 51 into the workpieces 2 to be controlled.

[0054] Regarding load control, when friction stirring is performed using, for example, a compression coil spring as an elastic member, it is possible to insert a stirring pin into a relatively soft 1000 series aluminum alloy, but there are cases where it is not possible to insert the stirring pin into a hard aluminum alloy.

[0055] This is because it is necessary to avoid compressing the compression coil spring beyond its maximum allowable amount (maximum deflection amount). In other words, it is difficult to apply a load to the rotary tool that exceeds the maximum deflection amount of the compression coil spring. That is, it is difficult to insert a stirring pin while applying simple load control to hard workpieces that require compression beyond the limit of the compression coil spring. If the maximum deflection amount of the compression coil spring is exceeded, there is a risk that the spring will break early.

[0056] Incidentally, for example, when the stirring pin 51 is brought into contact with the workpiece 2, as in the start position of friction stir welding, and the load applied to the rotary tool 1 is increased while the insertion proceeds, the generated reaction force (generated reaction force) and heat generation due to friction increase as the insertion amount increases over time. Normally, in friction stir welding, the softening of the material caused by the heat generated by the stirring pin 51 does not keep up with the insertion of the stirring pin 51, and the generated reaction force becomes the highest when the stirring pin 51 is pushed in to a predetermined depth. When the stirring pin 51 is inserted into the workpiece 2 to a predetermined depth and the pushing of the rotary tool 1 stops, the softening of the material caused by the heat generated by the stirring pin 51 catches up with the insertion amount of the rotary tool 1, and the load applied to the rotary tool 1 can be reduced, and the generated reaction force can be reduced. Such a state is called a "steady state".

[0057] 7 is a graph showing time and 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 51 is pushed furthest into the workpieces 2 at the start position of friction stir welding. Point P2 indicates the start position of the steady state of friction stir welding. The line rises to the right until it reaches point P1, indicating the state where the stirring pin 51 is being pushed into the workpieces 2. During friction stir welding, the generated reaction force gradually increases as the stirring pin 51 is pushed in and approaches a peak (point P1), and after the generated reaction force slightly decreases as the stirring pin 51 advances, it reaches a steady state (point P2) and becomes roughly constant.

[0058] The rotary tool 1 according to the present embodiment includes a restricting member 100 that restricts the movement of the stirring member 50 toward the base end side in the axial direction. As a result, when the rotary tool 1 is inserted where the generated reaction force (load) is maximum, or at a position where the shape of the workpiece 2 changes significantly, the restricting member 100 restricts the movement of the stirring member 50 within a range where the deflection amount generated in the elastic member 70 does not exceed the maximum deflection amount of the elastic member 70. Therefore, even if the workpiece 2 is relatively hard and requires a large load, it is possible to prevent the elastic member 70 from deforming beyond its limit. As a result, the stirring pin 51 can be inserted into the workpiece 2 that is relatively hard, while utilizing the elastic member 70, and damage to the elastic member 70 and the rotary tool 1 can be prevented.

[0059] In addition, while the stirring member 50, which is regulated by the regulating member 100, is supported by the regulating member 100 (while the regulating member 100 is in contact with and clamped between the slide shaft 31 and the bottom 24), the stirring member 50 is pressed against the workpiece 2, and the load applied by the joining device is applied to the stirring member 50 via the regulating member 100, so that the stirring member 50 can be inserted into the workpiece 2.

[0060] Thereafter, in the steady state, the generated reaction force (load) is reduced, the support of the stirring member 50 by the regulating member 100 is released, and the stirring member 50, which is no longer regulated by the regulating member 100, is able to move in the axial direction of the rotating shaft 12.

[0061] Also, in order to prevent the size of the rotary tool 1 from increasing, it is preferable that the outer diameter and free length of the elastic member 70 are as small (shortened) as possible. At a constant outer diameter, the shorter the free length of the elastic member 70 is, the larger the spring constant becomes, making it easier to insert the elastic member 70 into a relatively hard workpiece 2. However, when the spring constant is increased, the generated reaction force (load) against the amount of change tends to increase, decreasing robustness. In other words, when the spring constant is increased, the stirring pin 51 becomes more susceptible to the effect of the elastic member 70, resulting in a problem that the operation of the stirring pin 51 is unstable (difficult to control) in a steady state.

[0062] In this regard, according to the present embodiment, the restricting member 100 restricts the movement of the slide shaft 31 without increasing the spring constant of the elastic member 70, so that stress can be applied to the stirring member 50 via the restricting member 100. This allows the stirring member 50 to be inserted into a relatively hard workpiece 2. In addition, since the spring constant of the elastic member 70 does not need to be increased due to the provision of the restricting member 100, the flexibility in designing the elastic member 70 is increased, and robustness in the steady state can be improved, enabling stable control of the stirring pin 51.

[0063] The main body 10 further includes a cylindrical holder 21 and a slide shaft 31 that is accommodated in the center of the holder 21 so as to be slidable in the direction of the rotation axis and rotates synchronously with the holder 21, and the stirring member 50 is provided at the tip of the slide shaft 31. This allows the stirring member 50 to slide in the direction of the rotation axis while transmitting the rotational force from the main body 10 to the stirring member 50.

[0064] The elastic member 70 is housed inside the holder 21 and disposed between the base end of the slide shaft 31 and the bottom 24 on the base end side of the holder 21. This allows the force that the elastic member 70 receives from the stirring pin 51 side to be received by the bottom 24 of the holder 21. Therefore, even if the slide shaft 31 moves, the elastic member 70 stably biases the stirring pin 51 toward the tip side, thereby improving the accuracy of the load control of the stirring pin 51.

[0065] Further, a key groove 23 is formed in the holder 21, and a key 32 is formed in the slide shaft 31. This allows the slide shaft 31 and the stirring member 50 to rotate synchronously with the rotation of the rotating shaft and the holder 21, while allowing stable movement in the axial direction. This makes the operation of the stirring member 50 even more stable.

[0066] The elastic member 70 applies elastic force by at least one selected from a solid spring, a fluid spring, a magnetic force, and an electromagnetic force. With such a configuration, the elasticity of the elastic member 70 can be easily adjusted.

[0067] The stirring member 50 is connected to the slide shaft 31, and is columnar or frustum-shaped, has a flat or cone-shaped lower end surface, and is equipped with a shoulder 61 whose lower end surface abuts against the workpieces 2. Furthermore, the stirring pin 51 hangs down from the lower end surface of the shoulder 61. With this configuration, the elasticity of the elastic member 70 can be used to control the insertion depth of the stirring pin 51 and shoulder 61 into the workpieces 2. Furthermore, since the shoulder 61 presses against the surfaces of the workpieces 2, the surface finish after friction stir welding is improved.

[0068] The welding apparatus 3 includes a rotating tool 1, a power means, and a position control means. The rotating tool 1 is moved to a predetermined height position relative to the workpieces 2 by the position control means, and a stirring pin 51 is inserted into the workpieces 2 to perform friction stir welding. With such a welding apparatus 3, the elasticity of the elastic member 70 is utilized to perform friction stir welding while performing load control that controls the insertion depth of the stirring pin 51 into the workpieces 2.

[0069] In the joining device 3, the rotating tool 1 is a conventional type having a stirring pin 51 and a shoulder 61, and the stirring pin 51 and the shoulder 61 which rotates together with the stirring pin 51 are inserted into the workpieces 2 to perform friction stir welding of the workpieces 2. As a result, the shoulder 61 presses the surfaces of the workpieces 2, resulting in a good surface finish after friction stir welding.

[0070] In this joining method, the rotating tool 1 is moved to a predetermined height position relative to the workpieces 2, and a stirring pin 51 is inserted into the workpieces 2 to perform friction stir welding on the workpieces 2. According to this joining method, by utilizing the elasticity of the elastic member 70, friction stir welding can be performed while performing load control that controls the insertion depth of the stirring pin 51 into the workpieces 2.

[0071] In this joining method, the rotating tool 1 is a conventional type rotating tool equipped with a stirring pin 51 and a shoulder 61, and friction stir welding is performed by inserting the stirring pin 51 and the shoulder 61, which rotates together with the stirring pin 51, into the workpieces 2. As a result, the shoulder 61 presses the surfaces of the workpieces 2, resulting in a good surface finish after friction stir welding.

[0072] As described above, according to the rotary tool 1, the welding device 3, and the welding method, even in a state where the rotary tool 1, the welding device 3, and the welding method are mounted on a machining center that performs only position control, friction stir welding can be performed while controlling the load by utilizing the elastic member 70. In addition, according to the rotary tool 1, the welding device 3, and the welding method, by utilizing the restricting member 100, it is possible to insert a stirring pin while preventing damage to the elastic member 70 even in relatively hard members to be welded, and to perform friction stir welding while controlling the load.

[0073] [2. First modified example] Next, a rotary tool 1A according to a first modification will be described with reference to FIGS. 8 and 9. As shown in FIGS. 8 and 9, the rotary tool 1A according to the first modification has a slide means 80 provided inside the holder 21. The slide means 80 is provided on the inner peripheral surface of the holder 21. The slide means 80 is composed of a bearing groove 81 formed on the inner peripheral surface of the holder 21 and a plurality of balls 82, 82, . . . that slide in the bearing groove 81. The bearing groove 81 is formed in an elliptical shape that is long in the axial direction in a side view. The depth of the bearing groove 81 is smaller than the diameter of the ball 82. A plurality of balls 82 are disposed inside the bearing groove 81. A part of the ball 82 slides against the outer peripheral surface of the slide shaft 31, and the other part slides against the inner surface of the bearing groove 81. The other configurations are the same as those of the above embodiment, so the same reference numerals are used and the description will be omitted. According to the rotary tool 1A having such a configuration, the slide shaft 31 can be smoothly moved in the axial direction relative to the holder 21.

[0074] [3. Second Modification] Next, a rotary tool 1B according to a second modified example will be described with reference to Fig. 10. In the first embodiment, the stirring member 50 is a conventional type having a stirring pin 51 and a shoulder 61, but is not limited to this. As shown in Fig. 10, the stirring member 50a of the second modified example is a shoulderless type having no shoulder. Since the other configurations are the same as those of the above embodiment, the same reference numerals are used and the description will be omitted.

[0075] The shoulderless type stirring member 50a has a cylindrical connecting portion 41 connected to the slide shaft 31, and a stirring pin 53 formed integrally with the tip portion 41a of the connecting portion 41. The diameter of the connecting portion 41 is smaller than that of the slide shaft 31, and the connecting portion 41 is inserted into a cylindrical recess 31c provided in the tip portion (tip surface) 31a of the slide shaft 31. In this state, the stirring member 50a is fixed to the slide shaft 31, and the stirring member 50a is provided at the tip of the slide shaft 31. Therefore, the stirring member 50a rotates synchronously with the slide shaft 31, and moves in the axial direction of the rotation shaft 12 due to the sliding movement of the slide shaft 31.

[0076] The stirring pin 53 is integrally formed at its base end 54 with the tip end (tip surface) 41a of the connecting part 41, and protrudes (hangs down) from the tip end (lower end surface) 41a of the connecting part 41 toward the tip side. The stirring pin 53 has a tip 55 that tapers from the base end 54 side toward the tip. The diameter of the base end 54 of the stirring pin 53 is larger than the diameter of the tip end 41a of the connecting part 41 and smaller than the diameter of the slide shaft 31. A spiral groove may be provided on the outer circumferential surface of the stirring pin 51a.

[0077] In this modification, the base end 54 of the stirring pin 53 and the tip 41a of the connecting part 41 have different diameters and have a step on their outer circumferential surfaces, but the base end 54 of the stirring pin 53 and the tip 41a of the connecting part 41 may have the same diameter and their outer circumferential surfaces may be formed continuously. In this modification, the base end 54 of the stirring pin 53 and the tip 31a of the slide shaft 31 have different diameters and have a step on their outer circumferential surfaces, but the base end 54 of the stirring pin 53 and the tip 31a of the slide shaft 31 may have the same diameter and their outer circumferential surfaces may be formed continuously. In this modification, the stirring member 50a is provided separately from the slide shaft 31 and the two are connected to each other, but the stirring member 50a and the slide shaft 31 may be formed integrally. The shape of the connecting part 41 is not limited to a cylindrical shape, and may be a truncated cone shape.

[0078] According to the rotary tool 1B of this embodiment, similarly to the rotary tool 1 of the first embodiment, by utilizing the elasticity of the elastic member 70, it is possible to control the load, that is, to control the insertion depth of the stirring pin 53 into the workpieces 2. Furthermore, according to the rotary tool 1B having the shoulderless type stirring member of this embodiment, it is possible to reduce the pressing force of the rotary tool 1B during friction stir welding.

[0079] In addition, in the welding apparatus and welding method equipped with the rotary tool 1B equipped with such a shoulderless type stirring member, the position control means moves the rotary tool 1B to a predetermined height position relative to the workpieces, and in a state in which the slide shaft 31 and the connecting portion 41 are spaced apart from the workpieces, only the stirring pin 53 is inserted into the workpieces 2 to perform friction stir welding of the workpieces 2. According to the above-mentioned welding apparatus and welding method, the width of the plasticized region can be made smaller than when the shoulder portion of the rotary tool 1B is pushed in, and the pressing force of the rotary tool 1B can be reduced. In addition, the load on the friction stir welding apparatus can be reduced compared to when the shoulder portion of the rotary tool 1 is pushed in. In addition, a deep position of the butt joint can be welded without applying a large load to the friction stir welding apparatus. In addition, by providing the connecting portion 41, the stirring pin 53 formed integrally with the connecting portion 41 and the slide shaft 31 can be easily attached and detached.

[0080] [4. Second embodiment] Next, a rotary tool 1C according to a second embodiment will be described with reference to Fig. 11 and Fig. 12. The rotary tool 1C according to the second embodiment includes a main body 10 having a holder 21 and a slide shaft 31, an agitating member 50a having a connecting portion 41 and an agitating pin 53, an elastic member 70, and a regulating member 100C. Since the basic configuration is the same as that of the above-mentioned embodiment and modified example, the same reference numerals are used and the description will be omitted.

[0081] The restricting member (base end side fixed restricting member) 100C according to this embodiment is fixed to the bottom 24 of the holder 21. That is, the base end 100Cb of the restricting member 100C is always connected to the bottom 24. As shown in Fig. 12, before the elastic member 70 reaches the maximum deflection amount, the tip end 100Ca of the restricting member 100C comes into contact with the base end 31b of the slide shaft 31, and the movement of the slide shaft 31 and the stirring pin 53 (stirring member 50a) toward the base end can be restricted.

[0082] This embodiment can also achieve substantially the same effects as the first embodiment. Furthermore, according to this embodiment, since the regulating member 100C is provided on the bottom 24 of the holder 21, the regulating member can be prevented from moving freely inside the holder 21, and the regulating member and the elastic member 70 can be prevented from coming into contact with each other. Furthermore, since the regulating member 100C can be fixed at a fixed position, the tip end 100Ca of the regulating member 100C and the base end 31b of the slide shaft 31 can be brought into contact with each other at a fixed position, and the reaction force generated by the insertion of the rotary tool 1C can be received at a predetermined position, thereby allowing stable operation.

[0083] [5. Third embodiment] Next, a rotary tool 1D according to a third embodiment will be described with reference to Fig. 13 and Fig. 14. 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 member 50a having a connecting portion 41 and a stirring pin 53, an elastic member 70, and a regulating member 100D. Since the basic configuration is the same as that of the above-mentioned embodiment and modified example, the same reference numerals are used and the description will be omitted.

[0084] The restricting member (fixed distal end restricting member) 100D according to this embodiment is fixed to the slide shaft 31. That is, a distal end 100Da of the restricting member 100D and a base end 31b of the slide shaft 31 are always connected to each other. As shown in Fig. 14, before the elastic member 70 reaches the maximum deflection amount, a base end 100Db of the restricting member 100D comes into contact with a bottom 24 of the holder 21, and the movement of the slide shaft 31 and the stirring pin 53 (stirring member 50a) toward the base end can be restricted.

[0085] This embodiment can also achieve substantially the same effects as the first embodiment. Furthermore, according to this embodiment, since the regulating member 100D is provided on the slide shaft 31, it is possible to prevent the regulating member from moving freely inside the holder 21 and coming into contact with the elastic member 70. Furthermore, since the regulating member 100D can be fixed at a fixed position, the base end 100Db of the regulating member 100D can be brought into contact with the bottom 24 of the holder 21 at a fixed position, and the reaction force generated by the insertion of the rotating tool 1D can be received at a predetermined position to perform stable operation.

[0086] [6. Fourth embodiment] Next, a rotary tool 1E according to a fourth embodiment will be described with reference to Fig. 15 and Fig. 16. The rotary tool 1E according to the fourth embodiment includes a main body 10 having a holder 21 and a slide shaft 31, an agitating member 50a having a connecting portion 41 and an agitating pin 53, an elastic member 70, and a regulating member 100E. Since the basic configuration is the same as that of the above-mentioned embodiment and modified example, the same reference numerals are used and the description will be omitted.

[0087] The regulating member (middle regulating member) 100E according to this embodiment is fixed to the outer circumferential surface (side surface) of the slide shaft 31. In particular, the regulating member 100E is provided on the outer circumferential surface of the slide shaft 31 at the axial center. The regulating member 100E is a plate-shaped member that protrudes radially outward perpendicularly from the outer circumferential surface of the slide shaft 31. There may be one or more regulating members 100E. The regulating member 100E is formed so as to move in the axial direction in the through hole M that penetrates the holder 21 in the radially outward direction in association with the movement of the slide shaft 31. As shown in FIG. 16, the regulating member 100E comes into contact with the hole wall (middle part of the holder) Ma on the base end side of the through hole M before the elastic member 70 reaches the maximum deflection amount, and the movement of the slide shaft 31 and the stirring pin 53 (stirring member 50a) toward the base end side can be regulated.

[0088] In this embodiment, the through hole M of the holder 21 is set as the "middle part", but another part of the holder 21 may be set as the "middle part" and the middle part may be abutted against the regulating member 100E. Also, the through hole M and the regulating member 100E may be realized by the key groove 23 and the key 32.

[0089] This embodiment can also achieve substantially the same effects as the first embodiment. Furthermore, according to this embodiment, the regulating member 100E is provided on the outer circumferential surface of the slide shaft 31, so that interference with the elastic member 70 housed inside the holder 21 can be avoided. Therefore, even if 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, for example, the movement of the stirring member 50a can be restricted by the regulating member 100E provided on the outer circumferential surface. This increases the degree of freedom in design.

[0090] [7. Fifth embodiment] Next, a rotary tool 1F according to a fifth embodiment will be described with reference to Fig. 17 and Fig. 18. The rotary tool 1F according to the fifth embodiment includes a main body 10 having a holder 21 and a slide shaft 31, an agitating member 50a having a connecting portion 41 and an agitating pin 51B53, an elastic member 70, and a regulating member 100F. The basic configuration is the same as that of the above-mentioned embodiment and modified example, so the same reference numerals are used and the description will be omitted.

[0091] The regulating member (tip-side regulating member) 100F according to this embodiment is fixed to the outer circumferential surface (side surface) of the slide shaft 31. In particular, the regulating member 100F is provided on the outer circumferential surface on the tip side of the slide shaft 31. The regulating member 100F is a plate-like member that protrudes radially outward perpendicularly from the outer circumferential surface of the slide shaft 31. There may be one or more regulating members 100F. As shown in FIG. 18, the regulating member 100F comes into contact with the tip portion 21a of the holder 21 before the elastic member 70 reaches the maximum deflection amount, and the movement of the slide shaft 31 and the stirring pin 53 (stirring member 50a) toward the base end side can be regulated.

[0092] This embodiment can also achieve substantially the same effect as the first embodiment. Furthermore, according to this embodiment, the regulating member 100F is provided on the outer peripheral surface of the slide shaft 31, so that interference with the elastic member 70 housed inside the holder 21 can be avoided. Therefore, even if 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, for example, the movement of the stirring member 50a can be restricted by the regulating member 100F provided on the outer peripheral surface. Therefore, the degree of freedom in design can be increased. Furthermore, compared to the case where the through hole M and the regulating member 100E are realized by the key groove 23 and the key 32 and the regulating member 100E abuts against the key groove 23, according to this embodiment, the regulating member 100F abuts against the tip portion 21a of the holder 21, so that the load on the key groove 23 can be avoided.

[0093] [8. Sixth Embodiment] Next, a rotary tool 1G according to a sixth embodiment will be described with reference to Fig. 19 and Fig. 20. The rotary tool 1G according to the sixth embodiment includes a main body 10 having a holder 21 and a slide shaft 31, an agitating member 50a having a connecting portion 41 and an agitating pin 53, an elastic member 70, and a regulating member 100G. The basic configuration is the same as that of the above-described embodiment and modified examples, so the same reference numerals are used and the description will be omitted.

[0094] The regulating member (tip surface regulating member) 100G according to this embodiment is fixed to the tip (tip surface) 31a of the slide shaft 31. The regulating member 100G is a plate-shaped member that protrudes radially outward perpendicularly from the tip (tip surface) 31a of the slide shaft 31. The regulating member 100G protrudes outward from the outer circumferential surface of the slide shaft 31. There may be one or more regulating members 100G. As shown in FIG. 20, the regulating member 100G comes into contact with the tip 21a of the holder 21 before the elastic member 70 reaches the maximum deflection amount, and the movement of the slide shaft 31 and the stirring pin 53 (stirring member 50a) toward the base end can be regulated.

[0095] This embodiment can also achieve substantially the same effect as the first embodiment. Furthermore, according to this embodiment, the regulating member 100G is provided at the tip of the slide shaft 31, so that interference with the elastic member 70 housed inside the holder 21 can be avoided. Therefore, even if 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, for example, the movement of the stirring member 50a can be restricted by the regulating member 100G provided at the tip. Therefore, the degree of freedom in design can be increased. Furthermore, compared to the case where the through hole M and the regulating member 100E are realized by the key groove 23 and the key 32 and the regulating member 100E abuts against the key groove 23, according to this embodiment, the regulating member 100G abuts against the tip portion 21a of the holder 21, so that the load on the key groove 23 can be avoided.

[0096] [9. Seventh Embodiment] Next, a rotary tool 1H according to a seventh embodiment will be described with reference to Fig. 21 and Fig. 22. The rotary tool 1H according to the seventh embodiment includes a main body 10 having a holder 21 and a slide shaft 31, a stirring member 50h having a connecting portion 41 and a stirring pin 53h, and an elastic member 70. Since the basic configuration is the same as that of the above-mentioned embodiment and modified example, the same reference numerals are used and the description will be omitted.

[0097] The stirring member 50h according to this embodiment is a shoulderless type stirring member, like the second modified example. The outside diameter of the base end 54h of the stirring member 50h is larger than the outside diameter of the slide shaft 31. The outside diameter of the base end 54h of the stirring member 50h is larger than the inside diameter of the storage recess 22 of the holder 21. The tip 55h of the stirring pin 53h tapers from the base end 54h side toward the tip. As shown in FIG. 22, the base end 54h of the stirring pin 53h and the tip 21a of the holder 21 come into contact with each other before the elastic member 70 reaches the maximum deflection amount, and the movement of the slide shaft 31 and the stirring member 50h toward the base end side can be restricted. That is, in this embodiment, the stirring member 50h itself is a restricting member.

[0098] This embodiment can achieve substantially the same effects as the first embodiment. Furthermore, according to this embodiment, the agitating member 50h functions as a restricting member, so that interference with the elastic member 70 housed inside the holder 21 can be avoided. Therefore, even if the restricting member cannot be housed inside the holder 21 together with the elastic member due to the structure, shape, operation, or function of the elastic member, for example, the movement of the agitating member 50h itself can be restricted by the agitating member 50h. This increases the degree of freedom in design.

[0099] [10.Other] Although the embodiment of the present invention has been described above, appropriate design changes are possible within the scope of the present invention. In the above embodiment, the holder 21 is formed with the key groove 23, and the slide shaft 31 is formed with the key 32, but this is not limited thereto. The holder 21 may be formed with a key, and the slide shaft 31 may be formed with a key groove.

[0100] In the above embodiment, the elastic member 70 is accommodated inside the holder 21 and is disposed between the base end of the slide shaft 31 and the bottom 24 on the base end side of the holder 21, but is not limited thereto. The elastic member 70 may be disposed anywhere as long as it is a position that biases the stirring member 50 toward the tip end side. The arrangement of the regulating member may be changed in accordance with the arrangement of the elastic member 70. For example, it may be disposed so as to surround the lower part of the slide shaft. In this case, the elastic member 70 is positioned near the middle part between the slide shaft 31 and the stirring member 50, and the elastic member 70 acts evenly in the circumferential direction of the slide shaft 31. Therefore, even if the slide shaft 31 moves, the elastic member 70 stably biases the stirring member 50 toward the tip end side. Therefore, the accuracy of the load control of the stirring member 50 can be improved. In addition, an extension part that is extended in a columnar shape toward the upper end side is formed at the upper end of the slide shaft 31, and the elastic member 70 may be attached between the extension part of the slide shaft 31 and the bottom 24 on the base end side of the holder 21 while surrounding the extension part of the slide shaft 31. In this case, the extension portion may be formed to have a smaller diameter than the slide shaft 31 in accordance with the inner diameter of the holder 21. In this case as well, the accuracy of the load control of the stirring member 50 can be improved.

[0101] Also, in the above embodiment, a case has been described in which the regulating member 100 is cylindrical and disposed in a hollow portion of the elastic member 70. The regulating member may be tubular with an inner diameter larger than the outer diameter of the elastic member 70. In this case, the elastic member 70 may be disposed inside the regulating member, and the regulating member may be disposed so as to cover the outside of the elastic member 70. [Explanation of symbols]

[0102] 1 Rotate Tool 2 Parts to be joined 3 Joining equipment 10 Main body 11 Fixed part 12 Rotation axis 21 Holder 23 Keyway 31 Slide shaft 32 Key 50 Stirring member 51 Stirring pin 61 Shoulder 70 Elastic member 100 Regulatory member

Claims

1. A rotary tool used in a joining apparatus for performing friction stir joining of workpieces, a main body portion having a fixed portion attached to and fixed to the welding device and a rotating shaft for transmitting a rotational force from the welding device; a stirring member having a stirring pin that is inserted into the workpieces to perform friction stirring on the workpieces, the stirring member being rotatably provided by receiving a rotational force from the rotating shaft and being provided on the main body portion so as to be movable in an axial direction of the rotating shaft; an elastic member that biases the stirring member toward a tip side in an axial direction of the rotating shaft; and a restricting member that restricts the agitating member from moving toward a base end side in the axial direction of the rotating shaft, the regulating member regulates the movement of the stirring member so that an amount of deformation caused in the elastic member due to the movement of the stirring member does not exceed a maximum allowable amount of the elastic member. A rotary tool comprising:

2. The main body further includes a hollow cylindrical holder attached to the rotating shaft, and a slide shaft that is accommodated in a center of the holder so as to be slidable in the direction of the rotating shaft and rotates synchronously with the holder, The stirring member is provided at a tip of the slide shaft, The slide shaft is biased toward the tip side of the stirring member via the elastic member, The restricting member restricts the slide shaft from moving toward the base end side in the axial direction of the rotation shaft. The rotary tool of claim 1 .

3. The regulating member is provided within the holder, As the slide shaft moves, the base end of the slide shaft and a bottom portion of the base end side of the holder come into contact with the regulating member, thereby regulating the movement of the slide shaft. The rotary tool of claim 2 .

4. The regulating member is provided at a bottom portion on a base end side of the holder, As the slide shaft moves, the base end of the slide shaft comes into contact with the regulating member, thereby regulating the movement of the slide shaft. The rotary tool of claim 2 .

5. The regulating member is provided at a base end of the slide shaft, As the slide shaft moves, a bottom portion of the base end side of the holder comes into contact with the regulating member, thereby regulating the movement of the slide shaft. The rotary tool of claim 2 .

6. The regulating member is provided on an outer circumferential surface of the slide shaft, As the slide shaft moves, the regulating member comes into contact with an intermediate portion of the holder, thereby regulating the movement of the slide shaft. The rotary tool of claim 2 .

7. The regulating member is provided on an outer circumferential surface of the slide shaft, As the slide shaft moves, the regulating member comes into contact with the tip of the holder, thereby regulating the movement of the slide shaft. The rotary tool of claim 2 .

8. The regulating member is provided at a tip end of the slide shaft, As the slide shaft moves, the regulating member comes into contact with the tip of the holder, thereby regulating the movement of the slide shaft. The rotary tool of claim 2 .

9. the stirring member is the regulating member, As the slide shaft moves, the stirring member comes into contact with the tip of the holder, thereby restricting the movement of the slide shaft. The rotary tool of claim 2 .

10. the stirring member is connected to the slide shaft, has a columnar or frustum shape, and has a flat or cone-shaped lower end surface, and further has a shoulder with which the lower end surface comes into contact with the workpieces; The stirring pin depends from the lower end surface of the shoulder. A rotary tool according to any one of claims 2 to 9.

11. The stirring member further includes a connecting portion connected to the slide shaft and having a columnar or frustum shape, The stirring pin hangs down from the lower end surface of the connecting portion. A rotary tool according to any one of claims 2 to 9.

12. A joining apparatus comprising the rotary tool according to any one of claims 1 to 11, A power source for outputting a rotational force to be transmitted to the rotation shaft of the rotary tool; and a position control unit that holds the fixed portion of the rotation tool and controls a position of the rotation tool, the position control means moves the rotating tool to a predetermined height position relative to the workpieces, and the stirring pin is inserted into the workpieces to perform friction stir welding of the workpieces. A joining device characterized by:

13. The rotation tool of claim 10, The stirring pin and the shoulder rotating together with the stirring pin are inserted into the workpieces to perform friction stir welding of the workpieces. The joining device according to claim 12.

14. The rotation tool of claim 11, In a state where the connecting portion is spaced apart from the workpieces, only the rotating stirring pin is inserted into the workpieces, and friction stir welding is performed on the workpieces. The joining device according to claim 12.

15. The rotary tool according to any one of claims 1 to 11 is moved to a predetermined height position relative to the workpieces, and the stirring pin is inserted into the workpieces to perform friction stir welding of the workpieces. A bonding method comprising the steps of:

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