Method for manufacturing joining member, joining device, and joining component

Abstract

Provided is a friction stirring rotary member which makes high-strength joining possible while suppressing the occurrence of joining defects in friction stir joining. A method for manufacturing a joining component comprises a reception step in which a semi-finished product supplied from a pre-process facility of a production line is received by a joining device in the production line, a joining step in which friction stir joining of a member to be joined and the semi-finished product received via the receiving step is performed by a joining device to obtain a joining component, and a discharge step in which the joining component obtained via the joining step is discharged toward a post-process facility of the production line. The joining device includes an output shaft, a driving mechanism configured to cause the output shaft to rotate, and a friction stirring rotary member attached to the output shaft so as to rotate due to rotation transmitted from the driving mechanism. The friction stirring rotary member is configured such that, when said rotary member is attached to the output shaft, play is generated between the output shaft and a pin part inserted into the member to be joined during friction stirring, the play enabling vibration of the pin part relative to the output shaft.

Description

Method for manufacturing joined member, joining device, and joined component

[0001] The present invention relates to a method for manufacturing a welded member using friction stir welding (FSW), a welding device, and a welded component.

[0002] In Patent Document 1, the stirring pin is disposed on the main body so that it can rotate upon receiving rotational force from the main body and move axially along the rotating shaft. Furthermore, a first elastic member (e.g., a coil spring) is provided to bias the stirring pin toward the tip of the main body in the axial direction of the rotating shaft. Furthermore, the shoulder is disposed on the main body so that it can move independently of the stirring pin in the axial direction of the rotating shaft without receiving rotational force from the main body. Furthermore, a second elastic member is provided to bias the shoulder toward the tip of the main body in the axial direction of the rotating shaft. Even if the height of the workpieces changes while the stirring pin is being pressed into the workpieces at a constant height, the first elastic member deforms in accordance with the change in the height of the workpieces, thereby maintaining a constant insertion depth of the stirring pin (

[0041] ). The action of the first elastic member ensures that the stirring pin is inserted into the workpieces at a constant depth, thereby forming a plasticized region at a constant depth (

[0071] ). In this way, in the technique of Patent Document 1, the first elastic member biases the stirring pin toward the workpieces, and the stirring pin is inserted into the workpieces to a certain depth.

[0003] In Patent Document 2, the stirring pin and shoulder constitute an assembly. The assembly is rotatable relative to one another and is movable integrally in the axial direction of the rotating shaft. Furthermore, a first elastic member (e.g., a coil spring) is provided to bias the assembly toward the tip of the stirring pin in the axial direction of the rotating shaft. In the technology of Patent Document 2, the first elastic member also keeps the insertion depth of the stirring pin constant, and a plasticized region is formed at a constant depth (

[0033] ,

[0052] ).

[0004] In Patent Document 3, the rotary tool has a main body and a stirring member. The main body has a fixed portion that is attached to and fixed on a welding device, and a rotating shaft that transmits rotational force from the welding device. The stirring member has a stirring pin, is rotatably mounted upon receiving rotational force from the rotating shaft, and is mounted on the main body so as to be movable in the axial direction of the rotating shaft. Furthermore, an elastic member (coil spring) is provided that biases the stirring member toward the tip in the axial direction of the rotating shaft. In the technology of Patent Document 3, the elastic member also keeps the insertion depth of the stirring pin constant, and a plasticized region is formed at a constant depth (

[0035] ,

[0051] ).

[0005] In all of Patent Documents 1 to 3, the stirring pin is biased toward the workpieces to be joined by an elastic member (coil spring) and pressed against the workpieces to be joined, so that the insertion depth of the stirring pin is kept constant and a plasticized region is formed at a constant depth.

[0006] JP 2023-069370 A JP 2023-069371 A JP 2023-069372 A

[0007] With regard to friction stir welding, it is desired to provide a manufacturing method for a welded member, a welding apparatus, and a welded component that enable high-strength welding while suppressing the occurrence of welding defects.

[0008] An object of the present invention is to provide a method for manufacturing a welded member, a welding device, and a welded component that enable high-strength welding while suppressing the occurrence of welding defects in friction stir welding.

[0009] The present inventors have conducted extensive research in light of the above-mentioned problems and have obtained the following findings.

[0010] Conventionally, in friction stir welding, the support structure for the stirring pin has been designed based on the design concept of how to perform friction stirring with the stirring pin in a stable state. To achieve this, external force has been forcibly applied to the stirring pin, such as how to urge the stirring pin toward the workpieces to stably press and insert the workpieces. In Patent Documents 1 to 3, the elastic member is also provided to keep the insertion amount of the stirring pin constant and form a plasticized region at a constant depth. Patent Documents 1 to 3 fall within the scope of conventional design concepts.

[0011] In response to this, the inventors have shifted their thinking from the conventional design concept and discovered that by passively vibrating the pin portion inserted into the workpieces at a larger amplitude and / or frequency than the base vibration by contacting the workpieces undergoing plastic flow, it is possible to achieve a high-strength joint while suppressing the occurrence of joint defects, and have completed the present invention. This finding is completely different from the conventional friction stir welding described above. Therefore, even a person skilled in the art would not have easily arrived at this finding from conventional friction stir welding technology. The present invention can employ the following configurations.

[0012] (1) A friction stirring rotating member provided in a joining device that performs friction stir welding of workpieces, wherein the friction stirring rotating member is provided on an output shaft of a drive mechanism provided in the joining device so as to rotate with rotation output from the drive mechanism, and the friction stirring rotating member generates play between the output shaft and a pin portion that is inserted into the workpieces during friction stirring, allowing the pin portion to vibrate relative to the output shaft, and the play causes the vibration of the pin portion to have a larger amplitude and / or frequency than the vibration of the output shaft during friction stirring.

[0013] The friction stirring rotating member (1) has play between the output shaft and the pin portion, which allows the pin portion to vibrate relative to the output shaft. The friction stirring rotating member is configured such that the play causes the vibration of the pin portion during friction stirring to have a greater amplitude and / or frequency than the vibration of the output shaft. The output shaft of the drive mechanism vibrates in conjunction with the transmission of rotation from the drive mechanism during friction stirring. This vibration is also referred to as base vibration. Base vibration is vibration that inevitably occurs during friction stirring. During friction stirring, the vibration of the pin portion has a greater amplitude and / or frequency than the base vibration. During friction stirring, the pin portion rotates within the play while moving to pass the plastically flowing workpieces rather than resisting them. This movement causes the vibration of the pin portion. In other words, the vibration of the pin portion is caused by the play. The vibration of the pin portion is not vibration caused by output from a drive source other than the drive mechanism. The vibration of the pin portion is unlikely to interfere with the plastic flow of the workpieces. Furthermore, the vibration of the pin portion can be synchronized with the plastic flow of the workpieces to be welded. This allows the vibration of the pin portion to amplify the plastic flow of the workpieces to be welded. This vibration of the pin portion can therefore perform high-strength welding while suppressing the occurrence of welding defects. Additionally, the tilt angle (advance angle) of the friction stir rotating member and the output shaft may be 0 degrees. Even with a tilt angle of 0 degrees, good friction stir welding can be achieved. Because the above-mentioned vibration of the pin portion can be achieved by play, a complex spindle mechanism is not required. The generation of excessive frictional heat can be suppressed. The generation of excessive friction applied to the pin portion can be suppressed. By vibrating the pin portion, the transmission of vibration from the downstream side of the play to the upstream side in the power transmission path from the drive mechanism to the pin portion can be suppressed. The load applied to the output shaft can be reduced.

[0014] The friction stirring rotating member itself may have play within the friction stirring rotating member. The friction stirring rotating member may be configured so that play occurs between the friction stirring rotating member and the output shaft when the friction stirring rotating member is attached to an output shaft. The friction stirring rotating member may not have a pin portion, but rather, a pin portion may be attached to the friction stirring rotating member so that play occurs between the friction stirring rotating member and the pin portion. The joining device is not limited to a dedicated friction stir welding device, and may be, for example, a machining center, a robot, a milling machine, a multi-tasking machine, a general-purpose machine, or a portable device large enough for a user to hold in their hand to perform friction stir welding. The control conditions (position, load, spindle load, heat, pressure, etc.) of the joining device or its auxiliary mechanisms are not particularly limited. The joining conditions (feed speed, rotation speed, joining temperature, advance angle) are also not particularly limited. The materials of the workpieces are not particularly limited. The workpieces may be the same material or different materials. In the embodiments described below, the play is provided by a key (a mating key or a fixed key), but this example is not limiting. The structure for providing the play is not particularly limited, and a conventionally known structure can be employed. In addition to a key, components for providing the play, such as bolts, pins, and spherical bodies, can be employed. The play itself may also be provided by the shape of the friction stirring rotating member itself. The friction stirring rotating member may be divided into multiple (e.g., two) components, and the play may be formed by the fit between adjacent components. The amplitude and frequency of the vibration are not particularly limited, and can be adjusted by changing the amount of play or the weight of the component downstream of the play in the power transmission path from the drive mechanism to the pin portion. For example, the weight can be changed by installing a weight. In the joining device, the drive mechanism includes a rotating machine. The rotating machine may be, for example, a rotating electric machine or an internal combustion engine. The drive mechanism may include a transmission that changes the rotational speed output from the rotating machine and outputs the rotation. The transmission may be a speed reducer or a speed increaser. When the drive mechanism includes a transmission, the output shaft of the transmission corresponds to the output shaft of the drive mechanism. When the drive mechanism does not include a transmission, the output shaft of the rotating machine corresponds to the output shaft of the drive mechanism.In one embodiment, the backlash and margin in the drive mechanism do not constitute play. In one embodiment, the play is provided downstream of the upstream edge of the output shaft of the drive mechanism in the power transmission path from the drive mechanism to the pin portion.

[0015] (2) The friction stirring rotating member of (1), wherein the friction stirring rotating member comprises: a rotating shaft portion provided on the output shaft; and a tip portion configured to rotate by rotation transmitted from the rotating shaft portion and located distal to the rotating shaft portion, the tip portion having the pin portion and a base end side portion provided on the base end side of the pin portion, or having a base end side portion that does not have the pin portion but is configured to allow the pin portion to be detachably attached, the play is provided between the rotating shaft portion and the tip portion so as to enable vibration of the pin portion relative to the rotating shaft portion, and the friction stirring rotating member is configured so that, due to the play, the vibration of the pin portion during friction stirring has a larger amplitude and / or frequency than the vibration of the rotating shaft portion.

[0016] The friction stirring rotating member (2) has play between the rotating shaft and the tip. Due to this play, the vibration of the pin during friction stirring has a larger amplitude and / or frequency than the vibration of the output shaft. This vibration is not generated by the output from a drive source other than the drive mechanism. This vibration is unlikely to interfere with the plastic flow of the workpieces. Furthermore, this vibration can amplify the plastic flow of the workpieces. Therefore, high-strength joining can be achieved while suppressing the occurrence of joining defects.

[0017] When the pin portion and the base end portion are integrally configured, the pin portion is the portion that enters the workpiece, and the base end portion is the portion provided on the base end side of the pin portion, and thus the pin portion and the base end portion can be distinguished. On the other hand, when the pin portion and the base end portion are separable, for example, when the pin portion is detachable from the base end portion, the pin portion and the base end portion can be physically distinguished. For example, the pin portion corresponds to the tool, and the base end portion corresponds to the collet. When the tip portion does not have a pin portion, the tip portion may be the base end portion itself, which is configured to detachably attach the pin portion.

[0018] (3) The friction stirring rotating member of (2), wherein the tip portion has a surface contact portion at a height on the base end side of the pin portion where it contacts the surface of the workpiece, and the ratio of the diameter of the surface contact portion to the diameter of the pin portion adjacent to the surface contact portion closer to the tip than the surface contact portion is 1.8 or less, and thus the tip portion is configured to have a shoulder with a width small enough to satisfy the ratio, or to have no shoulder.

[0019] As described above, the vibration generated by the pin due to play does not interfere with the plastic flow of the workpieces and can amplify the plastic flow of the workpieces. Since the friction stir rotating member (3) has a narrow shoulder or no shoulder at all, the area of ​​the shoulder that contacts the surface of the workpieces, covering the workpieces undergoing plastic flow, is reduced. This makes it less likely for the shoulder to interfere with plastic flow. As a result, the effect of the pin vibration, which is to both minimize and amplify plastic flow, can be more effectively achieved. Furthermore, if the rotating shoulder is narrow or absent, the amount of heat applied to the workpieces by the rotating shoulder is reduced, but the effect of the pin vibration enables effective plastic flow. As a result, friction stir welding can be performed at lower temperatures. Friction stir welding at low temperatures can reduce the impact of temperature on the workpieces. This reduces the occurrence of thermal deformation and stress, potentially improving the mechanical properties of the welded components compared to those after conventional friction stir welding. Furthermore, lowering the temperature of friction stir welding reduces energy consumption. It may also become possible to use materials that are difficult to weld at high temperatures as welded components.

[0020] The ratio is not particularly limited, but is preferably 1.8 or less in the above (3). Furthermore, the ratio is more preferably 1.5 or less, even more preferably 1.3 or less, and particularly preferably 1.1 or less. This is because the occurrence of a situation in which the shoulder interferes with plastic flow can be suppressed. When the ratio is 1.0, the friction stir rotating element does not have a shoulder. A configuration without a shoulder is also a preferred embodiment of the friction stir rotating element. The ratio may be, for example, less than 2.0. In conventional friction stir welding, the ratio is, for example, 2 or more. The ratio may be 2 or more. By vibrating the shoulder together with the pin, the effect of preventing and amplifying plastic flow can be obtained. The shoulder may be configured not to rotate with the pin. Friction stir welding performed in a configuration in which the shoulder does not rotate with the pin is called Stationary Shoulder Friction Stir Welding (SSFSW). SSFSW allows for low heat input to the plastic flow zone (joint), thereby improving the mechanical properties, microstructure, and surface finish of the plastic flow zone. As described above, an embodiment with a small shoulder width or no shoulder allows friction stir welding to be performed at lower temperatures, and is therefore suitable for SSFSW. That is, when the friction stir rotating member has a shoulder, the shoulder may be configured to rotate together with the pin portion, or may be configured not to rotate together with the pin portion. A shoulder that does not rotate together with the pin portion may be installed on the friction stir rotating member or welding device as a separate unit from the friction stir rotating member. A shoulder that does not rotate together with the pin portion may be fixed to the friction stir rotating member or welding device in a manner that does not rotate at all, or may be configured to rotate separately from the pin portion.

[0021] (4) The friction stirring rotating member according to any one of (1) to (3), wherein the friction stirring rotating member is configured such that vibration of the pin portion is passively generated by contact with the workpieces undergoing plastic flow within the range of play.

[0022] In the friction stirring rotating member (4), the pin portion passively vibrates within the range of play due to contact with the plastically flowing workpieces. During friction stirring, the pin portion rotates within the range of play while moving to deflect rather than resist the plastically flowing workpieces. This movement passively generates vibration in the pin portion. Therefore, the vibration of the pin portion is unlikely to interfere with the plastic flow of the workpieces. Furthermore, this vibration can amplify the plastic flow of the workpieces. Therefore, high-strength joining can be achieved while suppressing the occurrence of joining defects.

[0023] (5) The friction stirring rotating member according to any one of (1) to (4), wherein the friction stirring rotating member is configured such that the pin portion vibrates in at least one of the axial direction, circumferential direction, and radial direction of the pin portion due to the play.

[0024] The friction stirring rotating member (5) can perform high-strength joining while suppressing the occurrence of joining defects by vibrating the pin portion toward at least one of the two sides.

[0025] When play is provided between the output shaft and the pin portion in the axial direction, the pin portion can vibrate in the axial direction. When play is provided in the circumferential direction, the pin portion can vibrate in the circumferential direction. When play is provided in the radial direction, the pin portion can vibrate in the radial direction. The play is provided in at least one of the axial, circumferential, and radial directions of the pin portion. For example, the following play can be provided between the output shaft and the pin portion: (A) play only in the axial direction; (B) play only in the circumferential direction; (C) play only in the radial direction; (D) a combination of axial play and circumferential play; (E) a combination of axial play and radial play; (F) a combination of circumferential play and radial play; or (G) a combination of circumferential play, circumferential play, and radial play. In the case of (A) above, the pin portion can vibrate at least in the axial direction. In the case of (B) above, the pin portion can vibrate at least in the circumferential direction. In the case of (C) above, the pin portion is capable of vibrating at least in the radial direction. In the case of (D) above, the pin portion is capable of vibrating at least in the axial and circumferential directions. In the case of (E) above, the pin portion is capable of vibrating at least in the axial and radial directions. In the case of (F) above, the pin portion is capable of vibrating at least in the circumferential and radial directions. In the case of (G) above, the pin portion is capable of vibrating in the axial, circumferential, and radial directions. Note that this paragraph describes the play provided between the output shaft and the pin portion. However, if the play is provided between the rotating shaft portion and the tip end, the "output shaft" in this paragraph can be read as "rotating shaft portion." The amount of play in either direction is not particularly limited and varies depending on the size of the joining device, but is preferably 0.0001 mm to 1 mm, more preferably 0.001 mm to 0.8 mm, and even more preferably 0.01 mm to 0.5 mm. Note that the axial direction is not necessarily limited to the vertical direction and can be determined by the arrangement of the workpieces and the pin portion.

[0026] (6) The friction stirring rotating member according to any one of (1) to (5), wherein the pin portion is configured to be free or substantially free relative to the output shaft within the range of play.

[0027] In the friction stirring rotating member (6), the pin portion is free or substantially free within the range of play, so that vibration of the pin portion occurs passively upon contact with the workpieces undergoing plastic flow, and has a larger amplitude and / or frequency than the base vibration. This vibration is less likely to interfere with the plastic flow of the workpieces. Furthermore, this vibration can amplify the plastic flow of the workpieces. This vibration enables high-strength joining while suppressing the occurrence of joining defects.

[0028] "Free" refers to a state in which there is no physical or mechanical constraint. "Substantially free" refers to a state in which the amplitude and / or frequency of the vibration of the pin portion during friction stirring is greater than the vibration of the output shaft, and within that range, constraint of the tip portion relative to the output shaft is permitted. The constraint is, for example, friction between adjacent members between the output shaft and the pin portion, or external stress caused by an elastic body or liquid, which will be described later.

[0029] (7) The friction stirring rotating member according to any one of (1) to (6), wherein the play is a gap or substantially a gap.

[0030] In the friction stirring rotating member of (7), the play is a gap or substantially a gap, so that the vibration of the pin portion occurs passively upon contact with the workpieces undergoing plastic flow, and has a larger amplitude and / or frequency than the base vibration. This vibration is less likely to interfere with the plastic flow of the workpieces. Furthermore, this vibration can amplify the plastic flow of the workpieces. This vibration enables high-strength joining while suppressing the occurrence of joining defects.

[0031] The gap is the space between the output shaft and the pin. "Substantially in the gap" means that the pin may have a liquid or an elastic body therein to the extent that the amplitude and / or frequency of the vibration of the pin during friction stirring can be made larger than the vibration of the output shaft.

[0032] (8) A joining device for friction stir welding of workpieces, the joining device comprising: a drive mechanism having an output shaft and configured to rotate the output shaft; and a pin portion configured to rotate by rotation transmitted from the drive mechanism and inserted into the workpieces during friction stirring, the pin portion having play between the output shaft and the pin portion to enable vibration of the pin portion relative to the output shaft, and configured such that vibration of the pin portion has a larger amplitude and / or frequency than vibration of the output shaft due to the play during friction stirring.

[0033] The joining device (8) has play between the output shaft and the pin portion, which allows the pin portion to vibrate relative to the output shaft. The joining device is configured so that the play causes the vibration of the pin portion to have a larger amplitude and / or frequency than the vibration of the output shaft during friction stirring. The output shaft vibrates in conjunction with the transmission of rotation from the drive mechanism during friction stirring. This vibration is similar to the base vibration described above. During friction stirring, the vibration of the pin portion has a larger amplitude and / or frequency than the base vibration. This vibration is generated by the play. This vibration is not generated by output from a drive source other than the drive mechanism. This vibration is unlikely to interfere with the plastic flow of the members to be joined. Furthermore, this vibration can amplify the plastic flow of the members to be joined. Therefore, high-strength joining can be performed while suppressing the occurrence of joining defects.

[0034] (9) A joining method for friction stir welding of workpieces by rotating a pin portion using rotation output from a drive mechanism and inserting the pin portion into workpieces, wherein, during friction stirring, vibrations having amplitudes and / or frequencies greater than base vibrations transmitted from the drive mechanism to the pin portion due to rotation of the drive mechanism are passively generated in the pin portion by contact with the workpieces undergoing plastic flow, and friction stirring is performed on the workpieces.

[0035] According to the joining method (9), the vibration of the pin portion is passively generated by contact with the workpieces undergoing plastic flow, and has a vibration and / or frequency greater than that of the base vibration. This vibration is less likely to interfere with the plastic flow of the workpieces. Furthermore, this vibration can amplify the plastic flow of the workpieces. This vibration enables high-strength joining while suppressing the occurrence of joining defects.

[0036] (10) A joining method for friction stir welding of workpieces by inserting a pin into workpieces while rotating the pin with rotation output from a drive mechanism, wherein the drive mechanism is feedback controlled so that the output of the drive mechanism changes in synchronization with or following the rotational fluctuation of the pin that occurs passively due to contact with the workpieces undergoing plastic flow, and friction stir welding is performed on the workpieces.

[0037] According to the joining method (10), the vibration of the pin is controlled by the drive mechanism so as to suppress or prevent the pin vibration from interfering with the plastic flow of the workpieces. This allows for freer plastic flow. Therefore, high-strength joining can be achieved while suppressing the occurrence of joining defects.

[0038] The above items (1) to (10) and the items described in the above columns (1) to (10) can be applied to and / or incorporated into (B1) to (B15) and (D1) to (D12) described below.

[0039] (B1) A method for manufacturing a welded component, the method comprising: a receiving step of receiving semi-finished products supplied from a preceding process facility of a production line into a joining device in the production line; a joining step of performing friction stir welding of the semi-finished products received in the receiving step and workpieces to be welded using the joining device, thereby obtaining the welded component; and a discharging step of discharging the welded component obtained in the joining step towards a succeeding process facility of the production line, the joining device comprising: an output shaft; a drive mechanism configured to rotate the output shaft; and a friction stirring rotating member provided on the output shaft so as to rotate by rotation transmitted from the drive mechanism, the friction stirring rotating member being configured, when provided on the output shaft, to generate play between the output shaft and a pin portion inserted into the workpieces during friction stirring, allowing the pin portion to vibrate relative to the output shaft.

[0040] The manufacturing method (B1) is characterized in that the above-mentioned joining device is used in the joining process. According to (B1), as with (1) above, it is possible to achieve high-strength joining while suppressing the occurrence of joining defects. Since the time and effort required to deal with joining defects, such as removing burrs, can be reduced, the efficiency of the production line can be improved. The production line, pre-process equipment, and post-process equipment are not particularly limited. The manufacturing method (B1) can be particularly suitably adopted in a production line for joined parts, which will be described later.

[0041] (B2) The manufacturing method of B1, wherein the friction stirring rotating member is configured such that, due to the play, vibration of the pin portion during friction stirring has a larger amplitude and / or frequency than vibration of the output shaft. According to (B2), it is possible to achieve a high-strength joint while suppressing the occurrence of joint defects.

[0042] (B3) The friction stirring rotating member comprises: a rotating shaft portion provided on the output shaft; and a tip portion configured to rotate by rotation transmitted from the rotating shaft portion and located distal to the rotating shaft portion, the tip portion having the pin portion and a base end side portion provided proximal to the pin portion, or having a base end side portion not having the pin portion but configured to allow the pin portion to be detachably attached, the play is provided between the rotating shaft portion and the tip portion so as to enable vibration of the pin portion relative to the rotating shaft portion, and the friction stirring rotating member is configured so that, due to the play, vibration of the pin portion has a larger amplitude and / or frequency than vibration of the rotating shaft portion during friction stirring.

[0043] (B4) The manufacturing method of B3, wherein the pin portion has a surface contact portion at a height where it contacts the surface of the workpiece, and the ratio of the diameter of the surface contact portion to the diameter of the pin portion adjacent to the surface contact portion closer to the tip than the surface contact portion is 1.8 or less, thereby causing the pin portion to have a shoulder with a width small enough to satisfy the ratio, or to have no shoulder.

[0044] (B5) The manufacturing method according to any one of B1 to B4, wherein the friction stirring rotating member is configured so that vibration of the pin portion is passively generated by contact with the workpieces undergoing plastic flow within the range of play.

[0045] (B6) The manufacturing method according to any one of B1 to B5, wherein the friction stirring rotating member is configured so that vibration of the pin portion occurs in at least one of the axial direction, circumferential direction, and radial direction of the pin portion due to the play.

[0046] (B7) The manufacturing method according to any one of B1 to B6, wherein the friction stirring rotating member is configured so that the pin portion is free or substantially free relative to the output shaft within the range of play.

[0047] (B8) The manufacturing method according to any one of (B1) to (7), wherein the play is a void or substantially a void. According to (B3) to (B8), excellent effects similar to those of (2) to (7) above can be obtained.

[0048] (B9) A method for manufacturing a joined part, the method comprising: a receiving process of receiving semi-finished products supplied from a preceding process facility of a production line into a joining device in the production line; a joining process of performing friction stir welding of the semi-finished products received in the receiving process and members to be joined using the joining device to obtain the joined part; and a discharging process of discharging the joined part obtained in the joining process towards a following process facility of the production line, wherein the joining device comprises: a drive mechanism having an output shaft and configured to rotate the output shaft; and a pin portion configured to rotate by rotation transmitted from the drive mechanism and to be inserted into the members to be joined during friction stirring, and the pin portion is configured to have play between the output shaft and the pin portion so as to allow vibration of the pin portion relative to the output shaft.

[0049] (B10) The manufacturing method of B9, wherein the pin portion is configured such that, due to the play, vibration of the pin portion during friction stirring has a larger amplitude and / or frequency than vibration of the output shaft.

[0050] (B11) A method for manufacturing a welded component, the method comprising: a receiving step of receiving semi-finished products supplied from a preceding process facility of a production line into a joining device in the production line; a joining step of performing friction stir welding of the semi-finished products received in the receiving step and workpieces to be welded by the joining device to obtain the welded component; and a discharging step of discharging the welded component obtained in the joining step towards a succeeding process facility of the production line, the welding device comprising: a drive mechanism having an output shaft and configured to rotate the output shaft; a pin portion configured to rotate by rotation transmitted from the drive mechanism and inserted into the workpieces during friction stir welding; a control unit that controls the drive mechanism so that the pin portion is inserted into the workpieces to be welded while rotating by the rotation output from the drive mechanism, thereby performing friction stir welding of the workpieces; and a detection unit that detects the rotation state of the pin portion. the control unit performs friction stirring on the workpieces while performing feedback control of the drive mechanism based on the rotational state of the pin portion detected by the detection unit so that the output of the drive mechanism changes in synchronization with or following the rotational fluctuation of the pin portion that occurs passively due to contact with the workpieces that are plastically flowing.

[0051] (B12) A joined part manufactured by the manufacturing method according to any one of B1 to B11.

[0052] (B13) The joining part according to B12, wherein the joining part is applied to any one of automobiles, railway vehicles, aircraft, ships, and rockets.

[0053] The friction stirring rotating member can suppress the occurrence of joining defects and can achieve high-strength joining. Therefore, the resulting joined member can be suitably applied to vehicles, and in particular, can be suitably applied to constructing the body of a vehicle.

[0054] (B14) The joining part according to B12, which is applied to any one of an electrode part, an air conditioning device, a water-cooled or air-cooled power control unit, a water-cooled or air-cooled battery case, a door panel, a shock absorber, a suspension link, a waveguide, an antenna, a motor cover, a sake brewing tank, a vacuum device part, a sputtering target material, and an embedded heater.

[0055] (B15) The joined part according to any one of B12 to B14, wherein the joined part is a part manufactured by friction stir welding a plurality of plate materials having different thicknesses, or a part manufactured by friction stir welding dissimilar materials.

[0056] The friction stir rotating member suppresses the occurrence of welding defects and enables high-strength welding. Therefore, high-quality friction stir welding can be performed even on multiple plate materials of different thicknesses or on dissimilar materials. The resulting welded parts are manufactured by high-quality friction stir welding. The dissimilar materials may be the following combinations: for example, a combination of dissimilar metals, a combination of resin and metal, a combination of metal casting and wrought metal, or a combination of ceramic and metal. Furthermore, at least one of the dissimilar materials may be the following: for example, a copper-aluminum dissimilar thin film material, a Ti-based material, an iron-based material, a chromium-based material, or a rare metal joint. The rare metals referred to here may or may not include Ag and Au.

[0057] The present invention may further employ the following configurations. The following configurations are inherently or implicitly included in the present invention, but are described below for clarity. (B13-1) A joined part according to B12, which is applied to a spacecraft, a special vehicle, a bicycle, a special defense vehicle, defense equipment, a linear motor, a linear motor car, and a drone. Examples of the spacecraft include artificial satellites, space stations, manned spacecraft, space probes, space telescopes, space cargo ships, space planes, and interplanetary probes. Examples of the special vehicles include self-propelled construction machinery such as truck cranes, trailer-mounted vehicles, etc. Examples of the bicycle include city bicycles, electrically assisted bicycles, sports bikes, and specialized bicycles for off-road use or racing. The joined part according to (B12) suppresses the occurrence of joining defects and provides a high-strength joint, so the joined part according to (B12) can be suitably used in applications under harsh environments such as those described in (B13-1). (B13-2) A joining part of B12 applied to facilities, devices, or equipment used in the following fields: food and beverage, liquid crystal / electronics / semiconductors, energy, power generation, batteries, solar cells, infrastructure, architecture, construction, medical care, vacuum, materials, equipment, machinery, metal / resin molding, home appliances, communications, IT, digital. The joining part of (B12) suppresses the occurrence of joining defects and provides high-strength joining, so the joining part of (B12) can be suitably used in a wide range of fields, including those shown in (B13-2). (B14-1) A joining part of B12 applied to any one of the following, or configured as any one of the following: Aluminum and aluminum alloy products, copper and copper alloy products, magnesium and magnesium alloy products, iron and iron alloy products, resin products, extrusion materials, drawing materials, casting materials, forging materials, thermal spraying and injection materials, shaping materials, metal products, dissimilar material joining products, thin film materials, bus bars, bus bars, silver and silver alloy products, gold and gold alloy products, titanium and titanium alloy products. (B14-2) Joined parts of B12 that apply to any one of the following.Chambers, vacuum chambers, backing plates, water-cooled plates, temperature control plates, heat sinks, nozzles, valves, susceptors, ion implantation equipment, mobile phones, smartphones, chargers, capacitors, Wi-Fi devices, electrical appliances, household products, televisions, games, washing machines, refrigerators, clocks, digital watches, decorative members, accessories, tableware, knives, scissors, balls, glasses, bats, electronic devices, cameras. (B14-3) Joining parts of B12 that apply to any one of the following: Inverter cases, frames, bodies, suspension parts, doors, door panels, floor panels, ceiling panels, inner panels, outer panels, stack boxes, crank arms, waveguides, antennas, motors, gears, mufflers, electrical components, oil pans, motor covers, honeycomb panels, double skin panels, tailored materials, fuselage panels, wing parts, bridges, bridge beams, wheelchairs, turbines, blades, converters, battery pack housings, wheels, accelerators, brakes, drive shafts, bumpers, bumper beams, spoilers, crash boxes, saddles, crank cases, hoods, radomes, cladding materials, battery coil materials, rollers, bearings, beam guides, heat shields. (B14-4) Joined parts of B12 that are applicable to any one of the following: Gas tanks, gas generators, fuel tanks, liquor tanks, hydrogen tanks, gasoline tanks, nuclear containers, solvent tanks, sonar, thermal power generators, hydroelectric generators, wind power generators, nuclear power generators, ion implantation equipment, film deposition equipment, etching equipment, coating equipment, agricultural machinery, construction machinery, machine tools, industrial machinery, pumps and compressors, textile machinery, office machinery, superconducting devices, neutron devices, exposure equipment. (B14-5) Joint parts of B12 that are applied to any one of the following: syringes, catheters, medical equipment, stands, jigs, blades, scaffolding, sashes, exterior walls, interior walls, roofs, interior fittings, piping, chairs, desks, beds, sofas, cabinets. (B14-6) Joint parts of B12 that are applied to any one of the following: syringes, catheters, medical equipment, stands, jigs, blades, scaffolding, sashes, exterior walls, interior walls, roofs, interior fittings, piping, chairs, desks, beds, sofas, cabinets.Capacitors, dryers, fishing tackle (reels), musical instruments, microwave ovens, air conditioners, electric fans, computers, forklifts, tractors, excavators, bulldozers, robotic arms, flanges, caterpillar tracks, hydraulic cylinders, presses, suspensions, pedals, handlebars, guardrails, pipelines, engine blocks, transmissions, pantographs, fences, handrails, landing gear, railway rails, traffic lights, electronic signboards, railroad crossings, propeller shafts, ducts, ventilation fans, suitcases, attaché cases, stepladders, inductors, aluminum trays, bathtubs, support frames, cooling layers, distributors, combiners, in-flight leads, robotic arms, mechanical arms, housings, capsules, valves, detectors, missiles.

[0058] (D1) A method for manufacturing a welded member, which produces a welded member by friction stir welding of workpieces using a welding device provided with a friction stirring rotating member, wherein the friction stirring rotating member is provided on an output shaft of a drive mechanism provided in the welding device so as to rotate by rotation output from the drive mechanism, and is configured to generate play between the output shaft and a pin portion inserted into the workpieces during friction stirring, which allows the pin portion to vibrate relative to the output shaft, and the method includes a joining step of friction stir welding the workpieces by moving the pin portion while rotating it so that at least one of the following conditions is satisfied: a temperature of a plastic flow portion resulting from friction stir welding is lower than a lower limit of an appropriate welding temperature for friction stir welding using a tool with no play, and a welding speed is higher than an upper limit of an appropriate welding speed for friction stir welding using a tool with no play.

[0059] According to (D1), high-strength joining can be achieved at high speed and / or low temperature while suppressing the occurrence of joining defects. High-strength and high-quality joining at high speed can improve the manufacturing efficiency of joined members. High-strength and high-quality joining at low temperature makes it possible to join workpieces made of materials that would be avoided by friction stir welding at high temperatures. As a result, it is possible to increase the freedom of selection of materials for the joining members and workpieces to which this manufacturing method is applied.

[0060] The "temperature of the plastic flow portion due to friction stir welding" refers to the temperature of the plastic flow portion due to friction stir welding itself, not the temperature affected by external factors. An example of an external factor is an artificial temperature change. The temperature change may be either heating or cooling. An example of an artificial temperature change is a temperature change due to contact of a fluid or a solid with the workpieces. The fluid may be a liquid such as water or a gas such as air. The solid may be a heating element such as a heater or a cooling element. The temperature not affected by such external factors is the temperature due to friction stir welding. This temperature is not the surface temperature of the workpieces, but is measured at a position inside the workpieces that is in contact with or close to the plastic flow portion. This temperature can be measured using a thermocouple inserted inside the workpieces. This temperature can be measured when the depth of the tip of the thermocouple is set to 2.5 mm from the surface of the workpieces and the tip of the thermocouple is set so that it is in contact with or close to the plastic flow portion in the radial direction of the pin.

[0061] The "tool without play" refers to a welding tool for conventional friction stir welding, as compared with the friction stir rotating member in (D1) above. Note that friction stir welding using a "tool without play" is performed without "the feedback control" described in (D12) below.

[0062] (D2) The method for manufacturing a joined member according to D1, wherein the friction stirring rotating member is configured so that, due to the play, the pin portion vibrates at the time of friction stirring with a larger amplitude and / or frequency than the output shaft.

[0063] According to (D2), similarly to the above (D1), it is possible to realize a high-strength joint at a high speed and / or a low temperature while suppressing the occurrence of joint defects.

[0064] (D3) The method for manufacturing a joined member according to D1 or D2, wherein the friction stirring rotating member comprises: a rotating shaft portion provided on the output shaft; and a tip portion configured to rotate by rotation transmitted from the rotating shaft portion and located distal to the rotating shaft portion, the tip portion having the pin portion and a base end side portion provided proximal to the pin portion, or having a base end side portion not having the pin portion but configured to allow the pin portion to be detachably attached, the play being provided between the rotating shaft portion and the tip portion so as to enable vibration of the pin portion relative to the rotating shaft portion, and the friction stirring rotating member is configured such that, due to the play, vibration of the pin portion during friction stirring has a larger amplitude and / or frequency than vibration of the rotating shaft portion.

[0065] (D4) The method for manufacturing a joined member according to D3, wherein the pin portion has a surface contact portion at a height where it contacts the surface of the workpiece, and the ratio of the diameter of the surface contact portion to the diameter of the pin portion adjacent to the surface contact portion closer to the tip than the surface contact portion is 1.8 or less, thereby causing the pin portion to have a shoulder with a width small enough to satisfy the ratio, or to have no shoulder.

[0066] (D5) The method for manufacturing a welded member according to any one of D1 to D4, wherein the friction stirring rotating member is configured so that vibration of the pin portion is passively generated by contact with the welded members that undergo plastic flow within the range of play.

[0067] (D6) The method for manufacturing a joined member according to any one of D1 to D5, wherein the friction stirring rotating member is configured so that vibration of the pin portion occurs in at least one of the axial direction, circumferential direction, and radial direction of the pin portion due to the play.

[0068] (D7) The method for manufacturing a joined member according to any one of D1 to D6, wherein the friction stirring rotating member is configured so that the pin portion is free or substantially free relative to the output shaft within the range of play.

[0069] (D8) The method for manufacturing a joined member according to any one of D1 to D7, wherein the play is a gap or substantially a gap.

[0070] According to (D3) to (D8), high speed and / or low temperature bonding can be realized, and excellent effects similar to those of (2) to (7) above can be obtained.

[0071] (D9) A joining device for friction stir welding of workpieces, the joining device comprising: a drive mechanism having an output shaft and configured to rotate the output shaft; and a pin portion configured to rotate by rotation transmitted from the drive mechanism and inserted into the workpieces during friction stirring, the pin portion being configured to have play between the output shaft and the pin portion so as to enable vibration of the pin portion relative to the output shaft, and the drive mechanism being configured to perform friction stir welding by moving the pin portion while rotating it so as to satisfy at least one of the following conditions: the temperature of a plastic flow portion resulting from friction stir welding is lower than the lower limit of an appropriate welding temperature for friction stir welding using a tool with no play; and the welding speed is higher than the upper limit of an appropriate welding speed for friction stir welding using a tool with no play.

[0072] (D10) The joining device according to D9, wherein the pin portion is configured such that, due to the play, vibration of the pin portion during friction stirring has an amplitude and / or frequency greater than vibration of the output shaft.

[0073] (D11) A method for manufacturing a welded member, in which an output shaft and a pin portion provided at a tip of the output shaft are rotated by rotation output from a drive mechanism, while the pin portion is inserted into workpieces to perform friction stir welding of the workpieces, thereby manufacturing a welded member, wherein the pin portion is configured to have play between the output shaft and the pin portion so as to enable vibration of the pin portion relative to the output shaft, and the method includes a joining step of friction stir welding the workpieces by moving the pin portion while rotating it so as to satisfy at least one of the following conditions: a temperature of a plastic flow portion resulting from friction stir welding is lower than a lower limit of an appropriate welding temperature for friction stir welding using a tool with no play, and a welding speed is higher than an upper limit of an appropriate welding speed for friction stir welding using a tool with no play.

[0074] According to (D9) to (D11), it is possible to realize high-strength bonding at high speed and / or low temperature while suppressing the occurrence of bonding defects.

[0075] (D12) A method for manufacturing a welded member, in which a pin portion is inserted into workpieces while rotating due to rotation output from a drive mechanism, thereby performing friction stir welding of the workpieces, wherein feedback control of the drive mechanism is performed so that the output of the drive mechanism changes in synchronization with or following rotational fluctuations of the pin portion that occur passively due to contact with the workpieces that undergo plastic flow, and friction stir welding is performed by moving the pin portion while rotating it so that at least one of the following conditions is satisfied: the temperature of the plastic flow portion caused by friction stir welding is lower than the lower limit of the appropriate welding temperature for friction stir welding without the feedback control, and the welding speed is higher than the upper limit of the appropriate welding speed for friction stir welding using the tool with no play.

[0076] According to (D12), it is possible to realize high-strength bonding at high speed and / or low temperature while suppressing the occurrence of bonding defects.

[0077] "Friction stir welding without feedback control" refers to conventional friction stir welding, as compared with conventional friction stir welding. Note that "friction stir welding without feedback control" is performed with the "tool without play" referred to in (D1) above.

[0078] (D13) A joined part manufactured by the manufacturing method according to any one of D1 to D8, D11, and D12.

[0079] (D14) The joining part according to D13, wherein the joining part is applied to any one of vehicles including automobiles, railway vehicles, aircraft, ships, and rockets.

[0080] The friction stirring rotating member can suppress the occurrence of joining defects and can achieve high-strength joining. Therefore, the resulting joined member can be suitably applied to vehicles, and in particular, can be suitably applied to constructing the body of a vehicle.

[0081] (D15) The joining part of D13, which is applied to any one of an electrode part, an air conditioning device, a water-cooled or air-cooled power control unit, a water-cooled or air-cooled battery case, a door panel, a shock absorber, a suspension link, a waveguide, an antenna, a motor cover, a sake brewing tank, a vacuum device part, a sputtering target material, and an embedded heater.

[0082] (D16) The joined part according to any one of D13 to D15, wherein the joined part is a part manufactured by friction stir welding a plurality of plate materials having different thicknesses, or a part manufactured by friction stir welding dissimilar materials.

[0083] The friction stir rotating member suppresses the occurrence of welding defects and enables high-strength welding. Therefore, high-quality friction stir welding can be performed even on multiple plate materials of different thicknesses or on dissimilar materials. The resulting welded parts are manufactured by high-quality friction stir welding. The dissimilar materials may be the following combinations: for example, a combination of dissimilar metals, a combination of resin and metal, a combination of metal casting and wrought metal, or a combination of ceramic and metal. Furthermore, at least one of the dissimilar materials may be the following: for example, a copper-aluminum dissimilar thin film material, a Ti-based material, an iron-based material, a chromium-based material, or a rare metal joint. The rare metals referred to here may or may not include Ag and Au.

[0084] The present invention may further employ the following configurations. The following configurations are inherently or implicitly included in the present invention, but are described below for clarity. (D14-1) A joined part according to D13, which is applied to a spacecraft, a special vehicle, a bicycle, a special defense vehicle, defense equipment, a linear motor, a linear motor car, and a drone. Examples of the spacecraft include artificial satellites, space stations, manned spacecraft, space probes, space telescopes, space cargo ships, space planes, and interplanetary probes. Examples of the special vehicles include self-propelled construction machinery such as truck cranes, trailer-mounted vehicles, and the like. Examples of the bicycles include city bicycles, electrically assisted bicycles, sports bikes, and specialized bicycles for off-road use or racing. The joined part according to (D13) suppresses the occurrence of joining defects and provides high-strength joining, so the joined part according to (D13) can be suitably used in applications under harsh environments such as those described in (D14-1). (D14-2) A joining part of D13 applied to facilities, devices, or equipment used in the following fields: food and beverage, liquid crystal / electronics / semiconductors, energy, power generation, batteries, solar cells, infrastructure, architecture, construction, medicine, vacuum, materials, equipment, machinery, metal / resin molding, home appliances, communications, IT, digital. The joining part of (D13) suppresses the occurrence of joining defects and provides high-strength joining, so the joining part of (D13) can be suitably used in a wide range of fields, including those shown in (D14-2). (D15-1) A joining part of D13 applied to any one of the following, or configured as any one of the following: Aluminum and aluminum alloy products, copper and copper alloy products, magnesium and magnesium alloy products, iron and iron alloy products, resin products, extrusion materials, drawing materials, casting materials, forging materials, thermal spraying and injection materials, shaping materials, metal products, dissimilar material joining products, thin film materials, bus bars, bus bars, silver and silver alloy products, gold and gold alloy products, titanium and titanium alloy products. (D15-2) Joined parts of D13 that apply to any one of the following.Chambers, vacuum chambers, backing plates, water-cooled plates, temperature control plates, heat sinks, nozzles, valves, susceptors, ion implantation equipment, mobile phones, smartphones, chargers, capacitors, Wi-Fi devices, electrical appliances, household products, televisions, games, washing machines, refrigerators, clocks, digital watches, decorative materials, accessories, tableware, knives, scissors, balls, glasses, bats, electronic devices, cameras. (D15-3) Joining parts of D13 that apply to any one of the following: Inverter cases, frames, bodies, suspension components, doors, door panels, floor panels, ceiling panels, inner panels, outer panels, stack boxes, crank arms, waveguides, antennas, motors, gears, mufflers, electrical components, oil pans, motor covers, honeycomb panels, double skin panels, tailored materials, fuselage panels, wing components, bridges, bridge beams, wheelchairs, turbines, blades, converters, battery pack housings, wheels, accelerators, brakes, drive shafts, bumpers, bumper beams, spoilers, crash boxes, saddles, crankcases, hoods, radomes, cladding materials, battery coil materials, rollers, bearings, beam guides, heat shields. (D15-4) Joined parts of D13 that apply to any one of the following: Gas tanks, gas generators, fuel tanks, liquor tanks, hydrogen tanks, gasoline tanks, nuclear containers, solvent tanks, sonar, thermal power generators, hydroelectric generators, wind power generators, nuclear power generators, ion implantation equipment, film deposition equipment, etching equipment, coating equipment, agricultural machinery, construction machinery, machine tools, industrial machinery, pumps and compressors, textile machinery, office machinery, superconducting devices, neutron devices, exposure equipment. (D15-5) Joint parts of D13 that are applied to any one of the following: syringes, catheters, medical equipment, stands, jigs, blades, scaffolding, sashes, exterior walls, interior walls, roofs, interior fittings, piping, chairs, desks, beds, sofas, cabinets. (D15-6) Joint parts of D13 that are applied to any one of the following: syringes, catheters, medical equipment, stands, jigs, blades, scaffolding, sashes, exterior walls, interior walls, roofs, interior decoration, piping, chairs, desks, beds, sofas, cabinets.Capacitors, dryers, fishing tackle (reels), musical instruments, microwave ovens, air conditioners, electric fans, computers, forklifts, tractors, excavators, bulldozers, robotic arms, flanges, caterpillar tracks, hydraulic cylinders, presses, suspensions, pedals, handlebars, guardrails, pipelines, engine blocks, transmissions, pantographs, fences, handrails, landing gear, railway rails, traffic lights, electronic signboards, railroad crossings, propeller shafts, ducts, ventilation fans, suitcases, attaché cases, stepladders, inductors, aluminum trays, bathtubs, support frames, cooling layers, distributors, combiners, in-flight leads, robotic arms, mechanical arms, housings, capsules, valves, detectors, missiles.

[0085] In the present invention, the following aspects can be adopted with regard to "play." While the following aspects are inherently or implicitly included in the present invention, they are described below for clarity. In the embodiments described below and the above description, the play is provided (I) using a member such as a key. However, (II) it may be provided by a fitting shape, or (III) it may be a combination of the aspects in (I) and (II) above. In the following description, it is assumed that, between the output shaft and the pin portion, member A on the output shaft side and member B on the pin portion side are adjacent to each other, and play is provided between member A and member B. Note that members A and B are not particularly limited. Furthermore, the configuration from the output shaft to the pin is not particularly limited, and may be output shaft-holder-collet-tool-pin, output shaft-holder-tool-pin, or output shaft-collet-tool-pin. The tool and pin may be integrated. The collet and holder may be integrated. The following example is applicable to any of these aspects. (I) Play provided using a connecting member such as a key. In this case, the connecting member is provided between members A and B. Members A and B may be located upstream (e.g., the output shaft and holder), in the middle (e.g., the holder and tool), or downstream (e.g., the tool and pin). Members such as a holder, collet, or tool may be divided between the output shaft side and the pin side, and a connecting member may be provided between these members to provide play. Furthermore, although a key is used as the connecting member in the embodiments described below and the above description, a pin or a bolt may also be used. The key is provided between the inner diameter side member and the outer diameter side member along the axial direction of the output shaft. That is, keyways are formed in each of the inner diameter side and outer diameter side members, and keys smaller than the keyways are provided in these keyways to provide play. The key is not particularly limited, and examples include parallel keys with a quadrangular (rectangular or square) cross section, wedge keys (triangular keys) tapered so that one end becomes thinner in the radial direction, crescent keys with a crescent-shaped cross section, round keys with a cylindrical cross section, oval keys, polygonal keys with pentagons or more, diamond keys, and other irregularly shaped keys (for example, T-shaped keys, fan-shaped keys), etc.The shape along the axial direction is not particularly limited, and examples include a straight key with a constant cross-sectional shape in the axial direction, a stepped key with a cross-sectional shape that changes stepwise in the axial direction, and a tapered key with a cross-sectional shape that changes gradually in the axial direction. Furthermore, a spherical body may be used as a connecting member instead of or in addition to a key. Multiple spherical bodies may be arranged side by side in a keyway (ball spline). A dimensional difference between the key and the keyway is provided in at least one of the radial, circumferential, and axial directions. This provides play that allows the pin portion to vibrate in that direction. The pin or bolt is provided so as to pass through both the inner diameter side member and the outer diameter side member along the radial direction of the output shaft. For example, play can be provided by forming a hole in one of the outer diameter side or inner diameter side member with a diameter larger than the diameter of the pin or bolt, and then installing the pin or bolt in the hole along the radial direction of the output shaft. A dimensional difference between the pin or bolt and the hole is provided in at least one of the radial, circumferential, and axial directions. This creates play that allows the pin portion to vibrate in that direction. (II) Play created by a fitting shape (spline): As with (I) above, the fit in this case may be located on any of the upstream, intermediate, and downstream sides. A member such as a holder, collet, or tool may be divided between the output shaft side and the pin portion side, and a fit may be formed between these members, thereby creating play. The spline may be provided over the entire circumferential direction, or may be provided over a portion of the circumferential direction. The spline shape is not particularly limited, and examples include a square spline (square groove), a round spline (round groove), a square spline (V groove), a sawtooth spline, an involute spline, and an involute serration. A dimensional difference between these fits is created in at least one of the radial, circumferential, and axial directions. This creates play that allows the pin portion to vibrate in that direction. (III) Play created by a combination of the above aspects (I) and (II): Play may be created by a combination of a connecting member and a fit. The play may be formed by any combination of the upstream side, the middle side, and the downstream side. Furthermore, the play may be formed by any combination of these.The play may be provided in multiple places.

[0086] According to the present invention, it is possible to provide a manufacturing method for a joined member, a joining device, and a joined component that enable high-strength joining while suppressing the occurrence of joining defects.

[0087] FIG. 1(a) is a cross-sectional view schematically illustrating a friction stir welding rotating member according to a first embodiment, and FIG. 1(b) is a cross-sectional view taken along line A-A thereof. FIG. 2(a) is a cross-sectional view schematically illustrating a pin portion and its vicinity of the friction stir welding rotating member shown in FIG. 1(a), and FIG. 2(b) is a cross-sectional view schematically illustrating a pin portion and its vicinity of a rotary tool according to a comparative example. FIGS. 3(a) to 3(t) are cross-sectional views schematically illustrating friction stir welding rotating members according to modified examples. FIG. 4(a) is a schematic diagram illustrating a method for manufacturing a welded member according to a second embodiment, FIG. 4(b) is a side view schematically illustrating a robot-type welding device used in the manufacturing method shown in FIG. 4(a), and FIG. 4(c) is a partially enlarged view thereof. FIG. 5(a) is a graph illustrating the appropriate welding temperature for friction stir welding using a tool with no play, and FIG. 5(b) is a graph illustrating the appropriate welding speed for friction stir welding using a tool with no play. FIG. 6(a) is a graph showing the joining temperatures of the example and the comparative example, and FIG. 6(b) is a graph showing the joining speeds of the example and the comparative example.

[0088] First Embodiment FIG. 1( a) is a cross-sectional view schematically illustrating a friction stirring rotating member 1 according to a first embodiment. FIG. 1( b) is a cross-sectional view taken along line A-A. In the figure, H, C, and T represent a holder, a collet, and a tool, respectively. AD, CD, and RD represent the axial direction, the circumferential direction, and the radial direction, respectively. These symbols may be omitted in other drawings, but are interpreted in the same manner as in this figure. In addition, in each figure, when adjacent members in the friction stirring rotating member 1 are hatched identically, this indicates that the members are fixed to each other. On the other hand, when different members are hatched differently, this indicates that the members are not fixed to each other. In addition, in each figure, the same components are designated by the same symbols.

[0089] The friction stirring rotating member 1 is provided in a joining device 3. The joining device 3 is a device that performs friction stir welding of workpieces 2. The joining device 3 has a drive mechanism 4. The friction stirring rotating member 1 is detachably attached to an output shaft 5 of the drive mechanism 4. The friction stirring rotating member 1 rotates together with the output shaft 5 so as not to be displaced relative to the output shaft 5.

[0090] The friction stirring rotating member 1 includes a metallic rotating shaft portion 10 and a metallic tip portion 20. The rotating shaft portion 10 corresponds to the holder H. The rotating shaft portion 10 has a generally cylindrical shape extending in the axial direction AD. The upper surface side of the rotating shaft portion 10 is fixed to the output shaft 5. The rotating shaft portion 10 has a bottomed hole on the lower surface of the rotating shaft portion 10 for receiving the tip portion 20. The bottomed hole is open downward. The tip portion 20 is provided within the bottomed hole.

[0091] The tip portion 20 has a pin portion 21 and a base end portion 22 provided on the base end side of the pin portion 21. The pin portion 21 corresponds to the tool T. The base end portion 22 corresponds to the collet C. The base end portion 22 has a generally cylindrical shape extending in the axial direction AD. The base end portion 22 has a bottomed hole on its underside for receiving the pin portion 21. The bottomed hole opens downward. The pin portion 21 is provided within the bottomed hole. The pin portion 21 is fixed to the base end portion 22 so as not to be displaced relative to the base end portion 22. The tip of the pin portion 21 is inserted into the workpiece 2 during friction stir welding, as shown in FIG. 1( a). In the figure, PF schematically indicates a plastic flow portion of the workpiece 2 during friction stir welding.

[0092] As shown in FIG. 1B , a plurality of grooves 25 are formed on the outer peripheral surface of the tip portion 20 at intervals in the circumferential direction CD. As shown in FIG. 1A , the grooves 25 are formed to extend in the axial direction AD. A rod-shaped metal fitting key 30 is provided in each groove 25. The inner portion of the fitting key 30 in the radial direction RD is recessed into the groove 25. The outer portion of the fitting key 30 in the radial direction RD is exposed outside the groove 25 in the radial direction RD. Grooves 15 are formed on the inner peripheral surface of the rotating shaft portion 10 at positions corresponding to the exposed portions of each fitting key 30. The length of the groove 15 in the circumferential direction CD is greater than the length of the fitting key 30 in the circumferential direction CD. Therefore, a play CP in the circumferential direction CD is generated within the groove 15. The play CP is provided between the rotating shaft portion 10 and the tip portion 20. The rotating shaft portion 10 is fixed to the output shaft 5, and the tip portion 20 includes a pin portion 21. Therefore, a play CP is provided between the output shaft 5 and the pin portion 21. The play CP is a gap or a substantial gap. The pin portion 21 is free or substantially free relative to the output shaft 5 within the range of the play CP. As shown in FIG. 1(b), the tip portion 20 is configured such that the play CP causes vibration CV in the circumferential direction CD relative to the rotating shaft portion 10 during friction stirring.

[0093] Furthermore, the friction stirring rotating member 1 has a play AP in the axial direction AD between the rotating shaft portion 10 and the tip portion 20. In other words, the play AP is provided between the output shaft 5 and the pin portion 21. The play AP is a gap or a substantial gap. The pin portion 21 is free or substantially free with respect to the output shaft 5 within the range of the play AP. As shown in FIG. 1( a), the pin portion 21 is configured such that the play AP generates vibration AV in the axial direction AD with respect to the output shaft 5 during friction stirring. From the viewpoint of joining quality, it is preferable to provide the play AP such that the tool T including the pin portion 21 can fall off together with the collet C from the rotating shaft portion 10, rather than providing the play AP between the pin portion 21 and the output shaft 5 with a tolerance such that the pin portion 21 does not fall off.

[0094] FIG. 2(a) is a cross-sectional view that schematically shows the pin portion 21 and its vicinity of the friction stirring rotating member 1 shown in FIG. 1(a).

[0095] The vibrations AV and CV of the pin portion 21 have a larger amplitude and / or frequency than those of the output shaft 5 (see FIG. 1(a)). The two-dot chain line in FIG. 2(a) shows the pin portion 21 when the vibrations AV and CV are occurring within the plastic flow portion PF.

[0096] Region Q is the region within the workpieces 2 that is affected by the vibrations AV and CV of the pin portion 21. That is, in region Q, the rotation of the pin portion 21 causes plastic flow in the workpieces 2. The pin portion 21 then comes into contact with the workpieces 2, which are undergoing plastic flow, within the range of the play AP and CP. The pin portion 21 is free or substantially free within the range of the play AP and CP. Therefore, passive vibrations AV and CV are generated in the pin portion 21. Because the vibrations AV and CV of the pin portion 21 are passive, they are not only unlikely to interfere with the plastic flow of the workpieces 2, but can also synchronize with and amplify the plastic flow.

[0097] The pin portion 21 has a surface contact portion 24 at a height where it comes into contact with the surface of the workpiece 2. The ratio (diameter SD / diameter PD) of the diameter SD of the surface contact portion 24 to the diameter PD of the pin portion 21 located directly below the surface contact portion 24 (the pin portion 21 that is closer to the tip of the surface contact portion 24 and adjacent to the surface contact portion 24) is 1.8 or less. As a result, the pin portion 21 has a shoulder 23 that is narrow enough to satisfy the ratio (diameter SD / diameter PD) ≦ 1.8.

[0098] Region P is a region near the surface of the workpieces 2. The pin portion 21 has a narrow shoulder 23, which makes it less likely that the shoulder 23 will impede plastic flow. The effect of the vibrations AV and CV of the pin portion 21 (the effect of not impeding plastic flow and amplifying it) can be more effectively achieved. Because the width of the shoulder 23 is small, the amount of heat generated during friction stirring is reduced, but the effect of the vibrations AV and CV of the pin portion 21 makes it possible to achieve effective plastic flow. As a result, friction stir welding can be performed at a lower temperature. In other words, because the width of the shoulder 23 is small, the shoulder 23 is less likely to impede plastic flow, and more amplified plastic flow can be achieved in region P.

[0099] 2B is a cross-sectional view schematically showing a pin portion and its vicinity of a rotary tool 1' according to a comparative example (prior art). The techniques disclosed in Patent Documents 1 to 3 correspond to this comparative example (prior art).

[0100] During friction stirring, the rotary tool 1' is biased downward by an elastic member (not shown). In the figure, F represents a biasing force. The biasing force F presses the rotary tool 1' against the workpieces 2', maintaining a constant insertion amount of the rotary tool 1' into the workpieces 2' within the plastic flow region PF'. The pin portion 21' does not generate vibrations AV and CV as shown in FIG. 2(a). Region Q' corresponds to region Q in FIG. 2(a). In region Q', even though the workpieces 2' undergo plastic flow around the pin portion 21', the pin portion 21' is biased downward by the biasing force F and remains in its position. As a result, the stationary pin portion 21' may hinder the plastic flow of the workpieces 2. Furthermore, the stationary pin portion 21' does not have the effect of amplifying the plastic flow of the workpieces 2.

[0101] In the rotary tool 1', the ratio (diameter SD' / PD') is 2 or more. The pin portion 21' has a wide shoulder 23'. In addition, the shoulder 23' is urged downward by the urging force F and pressed against the workpieces 2'. Therefore, in the region P', the shoulder 23' hinders plastic flow. Furthermore, because the width of the shoulder 23' is large, a large amount of heat is generated during friction stir welding, making it difficult to perform friction stir welding at low temperatures.

[0102] Figures 3(a) to 3(t) are schematic cross-sectional views of friction stirring rotating members 1 according to modified examples. The letters H, C, and T in Figures 3(a), 3(s), and 3(t) indicate a holder, a collet, and a tool, respectively. For convenience, the letters H, C, and T are omitted in Figures 3(b) to 3(r), but are the same as in Figures 3(a), 3(s), and 3(t).

[0103] [FIG. 3(a)] The frictional stirring rotating member 1 shown in FIG. 3(a) corresponds to the tool T as a whole, with the rotating shaft portion 10 corresponding to a part of the tool T and the tip portion 20 corresponding to a part of the tool T. The tip portion 20 has an integrally formed base end side portion 22 and pin portion 21. The tip portion 20 is attached to the rotating shaft portion 10 by being inserted into a bottomed hole provided on the underside of the rotating shaft portion 10. The underside of the rotating shaft portion 10 forms a shoulder 23. As shown in FIGS. 1(a) and 1(b), a fitting key 30 is provided between the rotating shaft portion 10 and the tip portion 20. As a result, the frictional stirring rotating member 1 has play AP and CP between the rotating shaft portion 10 and the tip portion 20. The frictional stirring rotating member 1 is attached to a collet C. A holder H and a collet C are fixedly provided on the output shaft 5, and the friction stirring rotating member 1 is provided on the output shaft 5 via the holder H and the collet C.

[0104] [Fig. 3(b)] The friction stirring rotating member 1 shown in Fig. 3(b) corresponds to the collet C and the tool T, the rotating shaft portion 10 corresponds to the collet C and a part of the tool T, and the tip portion 20 corresponds to a part of the tool T. The friction stirring rotating member 1 is attached to the output shaft 5 via a holder H. Except for this point, the embodiment in Fig. 3(b) is the same as Fig. 3(a).

[0105] [Fig. 3(c)] The friction stirring rotating member 1 shown in Fig. 3(c) corresponds to the holder H, collet C, and tool T, the rotating shaft portion 10 corresponds to the holder H, collet C, and part of the tool T, and the tip portion 20 corresponds to part of the tool T. The friction stirring rotating member 1 is provided on an output shaft 5. Except for this point, the embodiment in Fig. 3(c) is the same as Fig. 3(a) and Fig. 3(b).

[0106] [FIG. 3(d)] The frictional stirring rotating member 1 shown in FIG. 3(d) has a rotating shaft 10, an intermediate body 40, and a tip portion 20. The frictional stirring rotating member 1 corresponds to the collet C and the tool T. The rotating shaft 10 corresponds to the collet C. The intermediate body 40 corresponds to a part of the tool T. The tip portion 20 corresponds to a part of the tool T. The tip portion 20 is attached to the intermediate body 40 by being inserted into a bottomed hole provided on the underside of the approximately cylindrical intermediate body 40. The underside of the intermediate body 40 forms a shoulder 23. A fitting key 30 is provided between the intermediate body 40 and the tip portion 20. However, in the example shown in FIG. 3(d), the fitting key 30 provides play CP but not play AP. The tip portion 20 can vibrate in the circumferential direction CD (see FIG. 1) relative to the intermediate body 40. The intermediate body 40 is attached to the rotating shaft portion 10 by being inserted into a bottomed hole provided on the underside of the rotating shaft portion 10. This provides play AP between the rotating shaft portion 10 and the intermediate body 40. The intermediate body 40 is vibrable in the axial direction AD (see FIG. 1 ) relative to the rotating shaft portion 10. In this way, the play AP, CP provided between the rotating shaft portion 10 and the tip portion 20 does not necessarily have to be formed by the rotating shaft portion 10 and the tip portion 20. An intermediate body 40 that can be individually displaced relative to each of the rotating shaft portion 10 and the tip portion 20 may be interposed between the rotating shaft portion 10 and the tip portion 20. In this way, the friction stirring rotating member 1 as a whole has play AP, CP between the rotating shaft portion 10 and the tip portion 20.

[0107] [Fig. 3(e)] The friction stirring rotating member 1 shown in Fig. 3(e) has a rotating shaft portion 10, an intermediate body 40, and a tip portion 20, similar to Fig. 3(d). The friction stirring rotating member 1 corresponds to the holder H, the collet C, and the tool T. The rotating shaft portion 10 corresponds to the holder H. The intermediate body 40 corresponds to the collet C and part of the tool T. The tip portion 20 corresponds to part of the tool T. In the embodiment of Fig. 3(e), the position of the play AP differs from that of Fig. 3(d).

[0108] [Fig. 3(f)] In the embodiment of Fig. 3(f), the friction stirring rotating member 1 corresponds to the holder H, the collet C, and the tool T. The rotating shaft portion 10 corresponds to the holder H. The intermediate body 40 corresponds to the collet C. The tip portion 20 corresponds to the tool T. A fitting key 30 is provided between the intermediate body 40 and the tip portion 20, thereby providing a play CP between the intermediate body 40 and the tip portion 20. A play AP is provided between the rotating shaft portion 10 and the intermediate body 40.

[0109] [Fig. 3(g)] In the embodiment of Fig. 3(g), unlike Fig. 3(f), a fitting key 30 is provided between the rotating shaft portion 10 and the intermediate body 40, thereby providing play CP between the rotating shaft portion 10 and the intermediate body 40. Play AP is provided between the intermediate body 40 and the tip portion 20.

[0110] [Fig. 3(h)] In the embodiment of Fig. 3(h), the width of the shoulder 23 is wider than that of Fig. 1. The ratio is 2 or more. Because the shoulder 23 is integral with the pin portion 21, the shoulder 23 also generates vibrations similar to those of the pin portion 21. Therefore, even if the width of the shoulder 23 is wide, it is difficult to hinder the plastic flow of the workpieces 2, and it is possible to amplify the plastic flow. In this respect, the embodiment of Fig. 3(h) differs from the comparative example shown in Fig. 2(b). As mentioned above, the shoulder 23 may be separate from the pin portion 21 and configured not to rotate together with the pin portion 21.

[0111] [FIGS. 3(i) and 3(j)] The shapes of the tips of the pin portions 21 in the embodiments of FIG. 3(i) and FIG. 3(j) are different from those in FIG. 1. The tips of the pin portions 21 in FIG. 1 have a tapered truncated cone shape (a truncated cone shape in which the tip side is thinner than the base end side), whereas the tips of the pin portions 21 in FIG. 3(i) have a tapered inverted truncated cone shape (a truncated cone shape in which the tip side is thicker than the base end side). The tips of the pin portions 21 in FIG. 3(j) have a cylindrical shape. As such, the shape of the tips of the pin portions 21 is not particularly limited. Various shapes can be adopted as the shape of the pin portions 21.

[0112] [Fig. 3(k)] In the embodiment of Fig. 3(k), the ratio is 1.0, and the friction stir rotating member 1 does not have a shoulder. Because this friction stir rotating member 1 does not have a rotating shoulder, friction stir welding can be achieved at a lower temperature.

[0113] [Figures 3(l) and 3(m)] In the embodiment of Figure 3(l), unlike Figure 1, the frictional stirring rotating member 1 has only play AP in the axial direction AD (see Figure 1). In addition, in the embodiment of Figure 3(m), the frictional stirring rotating member 1 has only play CP in the circumferential direction CD (see Figure 1). In this way, the frictional stirring rotating member 1 may have play in only one direction among the axial direction AD, the circumferential direction CD, and the radial direction RD.

[0114] [FIG. 3(n)] In the embodiment of FIG. 3(n), the friction stirring rotating member 1 corresponds to the collet C and the tool T. The rotating shaft portion 10 corresponds to the collet C. The tip portion 20 corresponds to the tool T. The tip portion 20 has a pin portion 21 and a base end portion 22 that are integrally formed with each other. The tip portion 20 is attached to the rotating shaft portion 10 by being loosely fitted into a large-diameter, bottomed hole 17 provided on the underside of the rotating shaft portion 10. Because the diameter of the large-diameter, bottomed hole 17 is larger than the diameter of the base end portion 22, play RP in the radial direction RD (see FIG. 1) is provided around the base end portion 22. A fixed key 31 is fixed to the outer surface of the base end portion 22. A lateral through-hole 16 is provided in the rotating shaft portion 10 at a position corresponding to the fixed key 31. The lateral through-hole 16 provides play CP as well as play RP. That is, the tip portion 20 has play CP and play RP between it and the rotating shaft portion 10. The tip portion 20 is vibrable relative to the rotating shaft portion 10 in the circumferential direction CD and the radial direction RD.

[0115] [FIG. 3(o)] In the embodiment shown in FIG. 3(o), the friction stirring rotating member 1 has a rotating shaft portion 10, an intermediate body 40, and a tip portion 20. The friction stirring rotating member 1 corresponds to the holder H, collet C, and tool T. The rotating shaft portion 10 corresponds to the holder H. The intermediate body 40 corresponds to the collet C. The tip portion 20 corresponds to the tool T. The tip portion 20 has a pin portion 21 and a base end portion 22 that are integrally formed with each other. The tip portion 20 is attached to the intermediate body 40 by loosely fitting into a large-diameter, bottomed hole 17 provided on the underside of the intermediate body 40. Because the diameter of the large-diameter, bottomed hole 17 is larger than the diameter of the base end portion 22, play RP in the radial direction RD (see FIG. 1) is provided around the periphery of the base end portion 22. A fixing key 31 is fixed to the outer surface of the base end portion 22. A lateral through-hole 16 is provided in the intermediate body 40 at a position corresponding to the fixed key 31. The lateral through-hole 16 provides a play CP as well as a play RP. That is, the tip portion 20 has a play CP and a play RP between it and the intermediate body 40. The tip portion 20 can vibrate in the circumferential direction CD and the radial direction RD relative to the intermediate body 40. The intermediate body 40 is attached to the rotating shaft portion 10 by being inserted into a bottomed hole provided on the underside of the rotating shaft portion 10. This provides a play AP between the rotating shaft portion 10 and the intermediate body 40. The intermediate body 40 can vibrate in the axial direction AD (see FIG. 1 ) relative to the rotating shaft portion 10. As described above, the friction stirring rotating member 1 has play AP, CP, and RP between the rotating shaft portion 10 and the tip portion 20. Therefore, the tip portion 20 can vibrate in all directions, including the axial direction AD, the circumferential direction CD, and the radial direction RD, relative to the rotating shaft portion 10.

[0116] [Fig. 3(p)] In the embodiment of Fig. 3(p), unlike the embodiment of Fig. 1, the play AP, CP are not gaps, but are filled with a liquid 41 (e.g., lubricating oil). Such a friction-stirring rotating member 1 can also achieve the vibration of the pin portion 21 as described using Fig. 2(a), and is clearly different from the embodiment of Fig. 2(b). In other words, the play AP, CP are essentially gaps. The tip portion 20 is essentially free within the range of the play AP, CP.

[0117] [Fig. 3(q)] In the embodiment of Fig. 3(q), compared to the embodiment of Fig. 1, an elastic body 42 (e.g., an O-ring) is provided in the play AP between the rotating shaft portion 10 and the tip portion 20. Such a friction stirring rotating member 1 can also achieve vibration of the pin portion 21 as described using Fig. 2(a), and is clearly different from the embodiment of Fig. 2(b). In other words, the play AP, CP are essentially gaps. The tip portion 20 is essentially free within the range of the play AP, CP.

[0118] In the above example, a description has been given of a case in which the friction stirring rotating member 1 has a rotating shaft portion 10 and a tip portion 20, there is play between the rotating shaft portion 10 and the tip portion 20, and the tip portion 20 includes a pin portion 21. However, the friction stirring rotating member 1 is not limited to the above example, and the following aspects can be adopted, for example.

[0119] [Fig. 3(r)] In the embodiment of Fig. 3(r), the frictional stirring rotating member 1 corresponds to the collet C and the tool T. The frictional stirring rotating member 1 is configured as a single unit as a whole, and has a pin portion 21 and a shoulder 23. The frictional stirring rotating member 1 is configured to be attached to a holder H, thereby generating play AP between the frictional stirring rotating member 1 and the holder H. Due to the play AP, the frictional stirring rotating member 1 including the pin portion 21 vibrates in the axial direction AD relative to the output shaft 5 during frictional stirring.

[0120] [FIG. 3(s)] In the embodiment of FIG. 3(s), the frictional stirring rotating member 1 corresponds to the holder H. The frictional stirring rotating member 1 has a bottomed hole on its underside into which the collet C and tool T are inserted. The collet C and tool T are detachably attached to the frictional stirring rotating member 1 by inserting the collet C and tool T into the bottomed hole. The frictional stirring rotating member 1 does not have a pin portion. The pin portion is included in the tool T. The frictional stirring rotating member 1 has a bottomed hole on its upper surface for receiving an output shaft 5. The output shaft 5 is inserted into the bottomed hole, and the frictional stirring rotating member 1 is attached to the output shaft 5. The frictional stirring rotating member 1 is configured to generate play AP between the output shaft 5 and the frictional stirring rotating member 1 when attached to the output shaft 5. As a result, play AP is generated between the output shaft 5 and the pin portion of the tool T during frictional stirring. The play AP allows the pin portion to vibrate relative to the output shaft 5.

[0121] [FIG. 3(t)] In the embodiment shown in FIG. 3(t), the frictional stirring rotating member 1 has a rotating shaft portion 10 and a tip portion 20. The frictional stirring rotating member 1 corresponds to the holder H. The rotating shaft portion 10 is the upper portion of the holder H and is attached to the output shaft 5. The tip portion 20 is the lower portion of the holder H and is configured to rotate by rotation transmitted from the rotating shaft portion 10 and is located more distal than the rotating shaft portion 10. The tip portion 20 is configured to detachably attach a collet C and a tool T. That is, the tip portion 20 does not have a pin portion, but has a base end portion 22 configured to detachably attach a pin portion. Plays AP and CP are provided between the rotating shaft portion 10 and the tip portion 20 to allow vibration of the pin portion relative to the rotating shaft portion 10. Note that the frictional stirring rotating member 1 is not limited to the above example. The friction stirring rotating member 1 only needs to be configured so as to create play between the output shaft 5 and the pin portion 21 when attached to the output shaft 5, and does not necessarily have to be based on the distinction between the parts of the holder H, collet C, and tool T.

[0122] 1( a) and 1(b) , the welding device 3 according to the first embodiment is a welding device 3 including a friction stirring rotating member 1. The welding device 3 includes a drive mechanism 4 including an output shaft 5 and a pin portion 21. The pin portion 21 has play AP and CP between the output shaft 5 and the pin portion 21, which enable vibration AV and CV of the pin portion 21 relative to the output shaft 5. Due to the play AP and CP, the welding device 3 has vibrations AV and CV of the pin portion 21 during friction stirring that have a larger amplitude and / or frequency than the vibration (base vibration) of the output shaft 5. While the welding device 3 of this embodiment includes a friction stirring rotating member 1 having play AP and CP, the welding device 3 does not necessarily need to include a friction stirring rotating member 1 as long as there is play between the output shaft 5 and the pin portion 21.

[0123] 1( a) and 1(b) , the welding method according to the first embodiment can be performed by the above-described welding apparatus 3. In this welding method, the pin portion 21 is rotated by rotation output from the drive mechanism 4, and the pin portion 21 is inserted into the workpieces 2, thereby performing friction stir welding of the workpieces 2. In this welding method, friction stir welding is performed on the workpieces 2 in a state in which vibrations having amplitudes and / or frequencies greater than base vibrations transmitted from the drive mechanism 4 to the pin portion 21 by the rotation of the drive mechanism 4 are passively generated in the pin portion 21 by contact with the workpieces 2 that are undergoing plastic flow during friction stirring.

[0124] In a welding method according to another embodiment, the pin portion 21 is inserted into the workpieces 2 while being rotated by rotation output from the drive mechanism 4, thereby performing friction stir welding of the workpieces 2. In this welding method, friction stir welding is performed on the workpieces 2 while feedback controlling the drive mechanism 4 so that the output of the drive mechanism 4 changes in synchronization with or following the rotational fluctuation of the pin portion 21 that occurs passively due to contact with the workpieces 2 that undergo plastic flow. The rotational fluctuation can be detected by a conventionally known rotational speed sensor such as a resolver or encoder.

[0125] Furthermore, the numerical values, materials, structures, shapes, etc. described in the above-described embodiments are merely examples, and different numerical values, materials, structures, shapes, etc. may be used as necessary. Furthermore, in the above-described embodiments, the friction stirring rotating member 1 is located on top, the workpieces 2 are located on the bottom, and the friction stirring rotating member 1 and the workpieces 2 face each other in the vertical direction. That is, the axial direction is the same as the vertical direction. However, the axial direction does not necessarily have to be the same as the vertical direction. The axial direction is not particularly limited and may be, for example, horizontal. Furthermore, when the axial direction is the vertical direction, the friction stirring rotating member may be located on the bottom and the workpieces to be welded may be located on the top. Furthermore, the axial direction does not necessarily have to be fixed. When a joining device is configured by installing a friction stirring rotating member in the above-described portable device, the axial direction may change during operation.

[0126] Second Embodiment FIG. 4A is a schematic diagram illustrating a manufacturing method for a joined member according to a second embodiment. The manufacturing method for a joined component according to the second embodiment is performed on a production line PL. The production line PL includes, in this order, a front-end process equipment UE, a robotic joining apparatus A1, and a back-end process equipment DE. The manufacturing method includes a receiving process S1, a joining process S2, and a discharging process S3. In the receiving process S1, a semi-finished product (not shown) supplied from the front-end process equipment UE of the production line PL is received by the robotic joining apparatus A1 in the production line PL. In the joining process S2, the robotic joining apparatus A1 performs friction stir welding of the semi-finished product received in the receiving process S1 and the workpieces 2 to obtain a joined component (not shown). In the discharging process S3, the joined component obtained in the joining process S2 is discharged toward the back-end process equipment DE of the production line PL.

[0127] FIG. 4( b ) is a side view schematically illustrating a robot-type joining apparatus A1 used in the manufacturing method shown in FIG. 4( a ), and FIG. 4( c ) is a partially enlarged view illustrating the vicinity of the friction stir rotating member 1 of the robot-type joining apparatus A1. The robot-type joining apparatus A1 includes a robot arm A2. In this embodiment, the robot arm A2 is a multi-joint robot arm having multiple joints. However, the robot arm is not limited to this example and may have at least one joint. The robot arm A2 includes a joining device 3 provided at the tip of the robot arm A2. The joining device 3 includes an output shaft 5 provided at the tip of the robot arm A2 and a drive mechanism 4 configured to rotate the output shaft 5. The friction stir rotating member 1 is provided at the tip of the output shaft 5. The friction stir rotating member 1 according to each of the above-described embodiments may be employed. In this embodiment, the friction stir rotating member 1 is separate from the output shaft 5, and the friction stir rotating member 1 is attached to the output shaft 5. However, the robot-type joining apparatus A1 is not limited to this example. The robot-type welding apparatus A1 does not need to include the friction stirring rotating member 1, and it is sufficient that there is play between the output shaft 5 and the pin portion 21. Due to the play, the pin portion 21 vibrates at a greater amplitude and / or frequency than the output shaft 5 during friction stirring. In the robot-type welding apparatus A1 including the friction stirring rotating member 1, the friction stirring rotating member 1 is provided at the tip of the output shaft 5, and the pin portion 21 is provided at the tip of the output shaft 5. A position adjustment mechanism 3a is provided between the robot arm A2 and the output shaft 5. The position adjustment mechanism 3a is configured to adjust the insertion depth of the pin portion 21 into the workpieces 2 placed on the stage A6 in the direction facing the workpieces 2 and the pin portion 21. In this embodiment, the workpieces 2 are placed on the stage A6 so that they are approached by the pin portion 21 from above in the vertical direction, and are fixed to the stage A6 by a fixing mechanism (not shown) such as a jig. However, the manner in which the workpieces 2 are fixed is not limited to this example. The approach direction of the pin portion 21 is not limited to a vertically upward direction, but may be in another direction.The robot arm A2 according to this embodiment is capable of freely moving or operating the friction stirring rotating member 1 in three-dimensional space using a multi-joint structure and a servo motor (not shown). The robot arm A2 has legs A2-2, lower arms A2-3, upper arms A2-4, and wrists A2-5 and A2-6 mounted on a base A2-1. The number of joints is arbitrary. As the number of joints increases, a wider variety of movements becomes possible. In the robot arm A2, a position adjustment mechanism 3a and a joining device 3 are connected in this order to the tip of the wrist A2-6. The position adjustment mechanism 3a includes a position control motor 3a-1 that can rotate forward and backward, a rotating shaft 3a-2 directly connected to the position control motor 3a-1, and a slider 3a-3 attached to the rotating shaft 3a-2. Rotation of the position control motor 3a-1 rotates the rotating shaft 3a-2. The slider 3a-3 is configured to move along the rotation shaft 3a-2 as the rotation shaft 3a-2 rotates. When the position control motor 3a-1 rotates forward, the slider 3a-3 moves toward one end of the rotation shaft 3a-2. When the position control motor 3a-1 rotates reversely, the slider 3a-3 moves toward the other end of the rotation shaft 3a-2. In other words, the slider 3a-3 can reciprocate along the rotation shaft 3a-2. A welding device 3 is provided on the slider 3a-3, and as the slider 3a-3 reciprocates, the welding device 3 can also reciprocate along the rotation shaft 3a-2. The reciprocating movement of the welding device 3 can adjust the insertion depth of the pin portion 21 into the workpieces 2. The drive mechanism 4 includes a drive motor 4a, a first pulley 4b, a rotation transmission belt 4c, and a second pulley 4d. The drive mechanism 4 is configured so that the rotational force output from the drive motor 4a is transmitted to the friction stirring rotating member 1 provided on the tip side of the output shaft 5 via the first pulley 4b, the rotation transmission belt 4c, the second pulley, and the output shaft 5. Furthermore, the robot type joining device A1 is equipped with a control unit A5 (control device). The movement of the joining device 3 by the robot arm A2 and the joining operation of the joining device 3 are controlled by commands from the control unit A5. The control unit A5 is equipped with a memory unit (not shown). The memory unit stores data such as parameters related to the movement of the joining device 3 and the joining operation of the joining device 3.The robot-type joining device A1 may also include a detection unit (not shown) that detects the rotational state of the pin portion 21. The detection unit is not particularly limited as long as it is a sensor that can detect at least one parameter related to the rotational state of the pin portion 21. Examples of such parameters include the rotational speed, rotational angle, and rotational torque. This may allow the above-mentioned feedback control to be performed.

[0128] <Welding Temperature and Speed> The manufacturing method of a welded member according to this embodiment includes a joining step of performing friction stir welding on workpieces 2 by rotating and moving the pin portions 21 using a friction stir rotating member 1 in which play is generated between the output shaft 5 and the pin portions 21, allowing the pin portions 21 to vibrate relative to the output shaft 5, so that at least one of the following conditions is satisfied: (A) the temperature of the plastic flow portion resulting from friction stir welding is lower than the lower limit of the appropriate welding temperature for friction stir welding using a tool with no play, and (B) the welding speed is higher than the upper limit of the appropriate welding speed for friction stir welding using a tool with no play. This joining step can be incorporated into or applied to any of the above-described embodiments or inventions. In other words, in any of the above-described embodiments or inventions, the friction stir welding can be performed so as to satisfy at least one of the above-described conditions (A) and (B).

[0129] First, we will explain the above condition (A). Condition (A) relates to a comparison of the welding temperatures of two types of friction stir welding. Friction stir welding using a friction stir rotating member 1 in which play occurs between the output shaft 5 and the pin portion 21, allowing the pin portion 21 to vibrate relative to the output shaft 5, corresponds to the friction stir welding of the present invention. On the other hand, friction stir welding using a tool with no play corresponds to conventional friction stir welding. Simply put, condition (A) means that the welding temperature of the friction stir welding of the present invention is lower than the lower limit of the appropriate welding temperature for conventional friction stir welding. The comparison of the welding temperatures of the two types of friction stir welding in (A) above is based on the premise that the friction stir welding of the present invention is performed under the same or stricter conditions than the conventional friction stir welding conditions, with respect to conditions other than the welding temperature. In addition to a comparison under the same conditions, a comparison when the friction stir welding of the present invention is performed under stricter conditions is also included. Because the friction stir welding of the present invention is performed under stricter conditions, this comparison is as appropriate as a comparison under the same conditions. The term "harsher conditions" as used herein means that the friction stir welding of the present invention is performed under welding conditions that make it more difficult to achieve a high-quality joint than conventional friction stir welding. One example of this "harsher condition" is the tilt angle (advance angle) of the pin portion 21 (tool). Conventional friction stir welding is generally performed with a tilt angle (advance angle) of more than 0 degrees (e.g., 1 to 3 degrees) set on the tool. In contrast, the friction stir welding of the present invention is sometimes performed with a welding device that cannot set a tilt angle, because good welding is possible even if the pin portion 21 does not have a tilt angle set. In such cases, since a comparison under the same conditions is difficult, a comparison under conditions in which the friction stir welding of the present invention is performed under harsher conditions may be acceptable instead of a comparison under the same conditions.

[0130] FIG. 5( a) is a graph illustrating the appropriate welding temperature for friction stir welding using a tool with no play, i.e., conventional friction stir welding. Friction stir welding is performed under conditions where the temperature of the plastic flow portion of the workpieces 2 is within the appropriate welding temperature AWT (in other words, above the lower limit LL of the appropriate welding temperature AWT), enabling a high-quality weld SW. A high-quality weld SW is, for example, a weld in which the generation of cavities or burrs in the workpieces 2 is suppressed and damage to the tool (i.e., the friction stir rotating member) is suppressed. Note that suppression of tool damage is a concept that also includes suppression of tool wear. On the other hand, when friction stir welding is performed at an improper welding temperature IWT, a poor weld FW results. The improper welding temperature IWT is below the lower limit LL of the appropriate welding temperature AWT. A poor weld FW is a weld in which cavities or burrs are generated in the workpieces 2 or the tool is damaged. When the friction stir welding of the present invention is performed at a temperature lower than the lower limit LL of the appropriate welding temperature AWT for conventional friction stir welding, i.e., at an inappropriate welding temperature IWT, the above condition (A) is satisfied. The appropriate welding temperature AWT and its lower limit LL vary depending on the welding conditions. However, the fact that the welding temperature for friction stir welding is divided into the appropriate welding temperature AWT and the inappropriate welding temperature IWT, and that a boundary exists between them (i.e., the lower limit LL of the appropriate welding temperature AWT), is a characteristic common to friction stir welding. This characteristic exists regardless of the welding conditions. The welding conditions here mainly include the rotational speed of the pin portion 21 (and tool), the insertion depth of the pin portion 21, and the material of the workpieces. The tilt angle (advance angle) may also be included in the welding conditions. Regarding the evaluation of the welding, porosity is evaluated by visual inspection of the weld cross section (end mill cutting finish processing). This means that the cross section cut and finished using an end mill is evaluated with the naked eye. If necessary, the cross section is further evaluated by penetrant testing (PT). Burrs are evaluated by visual inspection.

[0131] Next, the above (B) will be explained. The above (B) relates to a comparison of the joining speeds of two types of friction stir welding. The two types of friction stir welding are similar to the above condition (A) and correspond to the friction stir welding of the present invention and conventional friction stir welding. Simply put, the above condition (A) means that the joining speed of the friction stir welding of the present invention is higher than the upper limit of the appropriate joining speed for conventional friction stir welding. The comparison of the joining speeds of the two types of friction stir welding in the above (B) is based on the premise that, with respect to conditions other than the joining speed, the friction stir welding of the present invention is performed under the same or stricter conditions as the joining conditions for conventional friction stir welding. In this respect, the above condition (B) is similar to the above condition (A).

[0132] FIG. 5(b) is a graph illustrating the appropriate welding speed for friction stir welding using a tool with no play, i.e., conventional friction stir welding. Friction stir welding is possible when the speed of the plastic flow portion of the workpiece 2 is within the appropriate welding speed AWS (in other words, below the upper limit UL of the appropriate welding speed AWS). On the other hand, friction stir welding performed at an improper welding speed IWS results in a poor welding speed FW. The improper welding temperature IWT is below the upper limit UL of the appropriate welding temperature AWS. The conditions for a good welding speed SW and a poor welding speed FW are the same as those for condition (A). When the friction stir welding of the present invention is performed at a speed higher than the upper limit UL of the appropriate welding speed AWS for conventional friction stir welding, i.e., at an improper welding speed IWS, the above condition (B) is satisfied. The appropriate welding speed AWS and its upper limit UL vary depending on the welding conditions. However, the fact that the joining speed of friction stir welding is divided into an appropriate joining speed AWS and an inappropriate joining speed IWS, and that a boundary exists between them (i.e., an upper limit UL of the appropriate joining speed AWS) is a characteristic common to friction stir welding. This characteristic exists regardless of the joining conditions. The joining conditions referred to here are also the same as in (B) above. The appropriate joining temperature AWT and appropriate joining speed AWS explained using Figures 5(a) and 5(b) vary depending on the joining conditions (e.g., the material of the workpieces 2), but the existence of a boundary between the appropriate and inappropriate conditions holds true regardless of the joining conditions. According to the friction stir welding of the present invention, high-quality joining is possible at high speeds and / or low temperatures compared to conventional friction stir welding, regardless of the joining conditions.

[0133] <Examples> FIG. 6A is a graph showing the bonding temperatures of the examples and comparative examples. First, the comparative examples will be described. The data for the comparative examples are as follows: CE1 to CE6. CE1: Bonding temperature = 395.4°C, bonding quality = good SW CE2: Bonding temperature = 347.6°C, bonding quality = good SW CE3: Bonding temperature = 301.1°C, bonding quality = good SW CE4: Bonding temperature = 252.4°C, bonding quality = poor FW CE5: Bonding temperature = 249.8°C, bonding quality = poor FW CE6: Bonding temperature = 201.9°C, bonding quality = poor FW Therefore, comparative examples CE1 to CE3 correspond to the appropriate bonding temperature AWT, and comparative examples CE4 to CE6 correspond to the improper bonding temperature IWT. The lower limit LL of the appropriate bonding temperature AWWT is located between comparative examples CE3 and CE4. Since the degree of defective FW in Comparative Example CE4 was slight, the lower limit LL is shown in the drawing at a position closer to Comparative Example CE4 than Comparative Examples CE3 and CE4.

[0134] The experimental conditions for the comparative example were as follows. An aluminum alloy plate (320 mm long x 50 mm wide x 10 mm thick, A6061 (T6)) was used as the workpiece 2. Friction stir welding was performed using a tool with no play. The tool tip had a shape of shoulder diameter - pin base diameter - pin tip diameter (φ12 - φ5 - φ3), with a lead angle of 3 degrees. Friction stir welding was performed at room temperature of 20°C using a dedicated friction stir welding machine, with a tool rotation speed of 1800 rpm, a welding depth of 5 mm, and a welding speed gradually increasing from 1 mm / min to 1500 mm / min in the longitudinal direction of the aluminum alloy plate. The welding temperature was measured using multiple thermocouples (manufactured by AS ONE Corporation, part number: 2-8107-02, model number: KTO-16100C) and a data logger (manufactured by Keyence Corporation, NR-TH08P). The multiple thermocouples were installed along the longitudinal direction of the aluminum alloy plate, spaced 30 mm apart from one another, with the tip of each thermocouple positioned 2.5 mm deep inside the workpiece 2 and in contact with or close to the plastic flow zone (2.5 mm from the pin center in the pin radial direction). This allowed the joining temperature to be measured when the tool passed near the thermocouple tip. The measurement results for each thermocouple are shown in order from CE1 to CE6. As the joining speed increased, the joining temperature decreased, as shown by the results for CE1 to CE6, and good quality joining SW was not achieved from CE4 onwards. The lower limit LL of the appropriate joining temperature AWT is considered to be near 250°C, or more specifically, slightly above 250°C.

[0135] The data for the example are as follows: PE1 to PE6. PE1: Bonding temperature = 357.8°C, Bonding quality = Good SW PE2: Bonding temperature = 307.3°C, Bonding quality = Good SW PE3: Bonding temperature = 271°C, Bonding quality = Good SW PE4: Bonding temperature = 219.3°C, Bonding quality = Good SW PE5: Bonding temperature = 208.2°C, Bonding quality = Good SW PE6: Bonding temperature = 144°C, Bonding quality = Good SW

[0136] The experimental conditions for the Example were as follows. The workpiece 2 was the same as in the Comparative Example. A friction stir rotating element 1 with circumferential and axial play was used as the tool (see Figure 1). The pin portion 21 had a shape similar to that of the Comparative Example, with a shoulder diameter, pin base diameter, and pin tip diameter of φ12, φ5, and φ3, but the lead angle was set to 0 degrees. Although the lead angles differ between the Example and Comparative Example, the Example was performed under more stringent conditions than the Comparative Example, allowing for an appropriate comparison. Friction stir welding was performed at room temperature of 20°C using an NC milling machine at a tool rotation speed of 1800 rpm, a welding depth of 5 mm, and in the longitudinal direction of the aluminum alloy plate, with the welding speed gradually increasing from 1 mm / min to 1500 mm / min. The welding temperature was measured in the same manner as in the Comparative Example. This measured the welding temperature when the pin portion 21 passed near the tip of the thermocouple. The measurement results for each thermocouple are shown in order from PE1 to PE6. As the joining speed increased, the joining temperature decreased, as shown in the results of PE1 to PE6. However, even when the joining temperature IWT reached the inappropriate joining temperature IWT of the comparative example, a good joining SW was achieved, as shown in PE4 to PE6.

[0137] FIG. 6( b) is a graph showing the welding speeds of the example and the comparative example. In the friction stir welding of the comparative example, a high-quality weld SW (black circles in the figure) was obtained at a relatively low welding speed and low rotational speed. The upper limit of the welding speed was 2000 mm / min. The upper limit of the rotational speed was 4500 rpm. This corresponds to the appropriate welding speed AWS for the friction stir welding of the comparative example. FIG. 6( b) also identifies the upper limit UL of the appropriate welding speed AWS based on the results of a poor weld FW (not shown). The region exceeding the upper limit UL of the appropriate welding speed AWS is the improper welding speed IWS. On the other hand, in the friction stir welding of the example, a high-quality weld SW (white circles in the figure) was obtained not only within the range of the appropriate welding speed AWS, but also at the improper welding speed IWS, exceeding the upper limit of the appropriate welding speed AWS.

[0138] The experimental conditions for the comparative example were as follows. An aluminum alloy plate (500 mm long x 200 mm wide x 10 mm thick, A6061 (T6)) was used as the workpiece 2. Friction stir welding was performed using a tool with no play. The tool tip had a shape where the shoulder diameter, the pin base diameter, and the pin tip diameter were φ10, φ5, and φ3, respectively, and the lead angle was set to 3 degrees. Friction stir welding was performed at room temperature using a dedicated friction stir welding machine, with the welds spaced apart parallel to each other along the longitudinal direction of the aluminum alloy plate for each combination of rotational speed and welding speed shown in Figure 5(b) to a welding depth of 4 mm. Note that friction stir welding was performed for only some of the combinations of rotational speed and welding speed shown in the figure, not all of them. In Figure 6(b), combinations that produced good-quality welds SW are marked with black circles. Furthermore, based on the results of poor welds FW, the upper limit UL of the appropriate welding speed AWS was determined.

[0139] The experimental conditions for the example were as follows. The workpiece 2 used was the same as in the comparative example. The tool used was a friction stir rotating element 1 with circumferential and axial play (see Figure 1). The pin portion 21 had a shape similar to the comparative example tool, with a shoulder diameter, pin base diameter, and pin tip diameter of φ10, φ5, and φ3, but the lead angle was set to 0 degrees. Although the lead angles differ between the example and the comparative example, the example was performed under more stringent conditions than the comparative example, allowing for an appropriate comparison. Friction stir welding was performed at room temperature using a machining center, with the aluminum alloy plates spaced apart and parallel to each other, along the longitudinal direction of the aluminum alloy plates, to a welding depth of 4 mm, for each combination of rotational speed and welding speed shown in Figure 5(b). Note that friction stir welding was performed for only some, but not all, of the combinations of rotational speed and welding speed shown in the figure. In Figure 6(b), combinations that produced high-quality welds are marked with white circles. Combinations in which good joint SW was obtained in both the example and the comparative example are marked with both white and black circles.

[0140] Friction stirring rotating member: 1 Workpiece to be joined: 2 Joining device: 3 Drive mechanism: 4 Output shaft (of drive mechanism): 5 Rotating shaft portion: 10 Groove: 15 Lateral through-hole: 16 Large diameter bottomed hole: 17 Tip portion: 20 Pin portion: 21 Base end side portion: 22 Shoulder: 23 Surface contact portion: 24 Groove: 25 Fitting key: 30 Fixed key: 31 Intermediate body: 40 Liquid: 41 Elastic body: 42

Claims

1. A method for manufacturing a joined part, the method comprising: a receiving process for receiving semi-finished products supplied from a front-end facility of a production line into a joining device in the production line; a joining process for obtaining the joined part by using the joining device to perform friction stir welding of the semi-finished products received in the receiving process and members to be joined; and a discharging process for discharging the joined part obtained in the joining process toward a rear-end facility of the production line, the joining device comprising: an output shaft; a drive mechanism configured to rotate the output shaft; and a friction stirring rotating member provided on the output shaft so as to rotate by rotation transmitted from the drive mechanism, the friction stirring rotating member being configured, when provided on the output shaft, to generate play between the output shaft and a pin portion inserted into the members to be joined during friction stirring, allowing the pin portion to vibrate relative to the output shaft.

2. The manufacturing method according to claim 1, wherein the friction stirring rotating member is configured such that, due to the play, vibration of the pin portion during friction stirring has an amplitude and / or frequency greater than vibration of the output shaft.

3. The manufacturing method according to claim 1 or 2, wherein the friction stirring rotating member comprises a rotating shaft portion provided on the output shaft, and a tip portion configured to rotate by rotation transmitted from the rotating shaft portion and located further tip than the rotating shaft portion, the tip portion having the pin portion and a base end side portion provided on the base end side of the pin portion, or having a base end side portion not having the pin portion but configured to allow the pin portion to be detachably attached, the play is provided between the rotating shaft portion and the tip portion so as to enable vibration of the pin portion relative to the rotating shaft portion, and the friction stirring rotating member is configured such that, due to the play, the vibration of the pin portion during friction stirring has a larger amplitude and / or frequency than the vibration of the rotating shaft portion.

4. The manufacturing method described in claim 3, wherein the pin portion has a surface contact portion at a height where it contacts the surface of the workpiece, and the ratio of the diameter of the surface contact portion to the diameter of the pin portion adjacent to the surface contact portion closer to the tip than the surface contact portion is 1.8 or less, whereby the pin portion is configured to have a shoulder with a width small enough to satisfy said ratio, or to have no shoulder.

5. A manufacturing method as described in any one of claims 1 to 4, wherein the friction stirring rotating member is configured so that vibration of the pin portion is passively generated by contact with the workpieces undergoing plastic flow within the range of play.

6. A manufacturing method as described in any one of claims 1 to 5, wherein the friction stirring rotating member is configured so that vibration of the pin portion occurs in at least one of the axial direction, circumferential direction and radial direction of the pin portion due to the play.

7. A manufacturing method according to any one of claims 1 to 6, wherein the friction stirring rotating member is configured so that the pin portion is free or substantially free relative to the output shaft within the range of play.

8. A method according to any one of claims 1 to 7, wherein the clearance is a void or substantially a void.

9. A method for manufacturing a joined part, comprising: a receiving process of receiving semi-finished products supplied from a front-end facility of a production line into a joining device in the production line; a joining process of obtaining the joined part by using the joining device to perform friction stir welding of the semi-finished product received in the receiving process and members to be joined; and a discharging process of discharging the joined part obtained in the joining process toward a rear-end facility of the production line, wherein the joining device comprises: a drive mechanism having an output shaft and configured to rotate the output shaft; and a pin portion configured to rotate by rotation transmitted from the drive mechanism and inserted into the members to be joined during friction stirring, and the pin portion is configured to have play between the output shaft and the pin portion so as to enable vibration of the pin portion relative to the output shaft.

10. The manufacturing method according to claim 9, wherein the pin portion is configured such that, due to the play, the vibration of the pin portion during friction stirring has an amplitude and / or frequency greater than the vibration of the output shaft.

11. A method for manufacturing a welded part, comprising: a receiving process for receiving a semi-finished product supplied from a front-end facility of a production line into a joining device in the production line; a joining process for obtaining the welded part by using the joining device to perform friction stir welding of the semi-finished product received in the receiving process and members to be welded; and a discharging process for discharging the welded part obtained in the joining process toward a rear-end facility of the production line, the joining device comprising: a drive mechanism having an output shaft and configured to rotate the output shaft; a pin portion configured to rotate by the rotation transmitted from the drive mechanism and inserted into the members to be welded during friction stirring; a control unit for controlling the drive mechanism so that the pin portion is inserted into the members to be welded while rotating by the rotation output from the drive mechanism, thereby performing friction stir welding of the members to be welded; and a detection unit for detecting the rotation state of the pin portion. the control unit performs friction stirring on the workpieces while performing feedback control of the drive mechanism based on the rotational state of the pin portion detected by the detection unit so that the output of the drive mechanism changes in synchronization with or following the rotational fluctuation of the pin portion that occurs passively due to contact with the workpieces undergoing plastic flow.

12. A joined part manufactured by the manufacturing method according to any one of claims 1 to 11.

13. The joining part according to claim 12, which is applied to any one of vehicles including automobiles, railway vehicles, aircraft, ships, and rockets.

14. The joining part according to claim 12, which is applied to any one of an electrode part, an air conditioning device, a water-cooled or air-cooled power control unit, a water-cooled or air-cooled battery case, a door panel, a shock absorber, a suspension link, a waveguide, an antenna, a motor cover, a sake brewing tank, a vacuum device part, a sputtering target material, and an embedded heater.

15. The joined part according to any one of claims 12 to 14, which is a part manufactured by friction stir welding a plurality of plate materials of different thicknesses, or a part manufactured by friction stir welding a plurality of members made of different materials.

16. A method for manufacturing a welded member, comprising manufacturing a welded member by performing friction stir welding of workpieces using a joining device provided with a friction stirring rotating member, wherein the friction stirring rotating member is provided on an output shaft of a drive mechanism so as to rotate by the rotation output from the drive mechanism of the joining device, and is configured to generate play between the output shaft and a pin portion inserted into the workpieces during friction stirring, which allows the pin portion to vibrate relative to the output shaft, and the method comprises a joining step of performing friction stir welding of the workpieces by moving the pin portion while rotating it so as to satisfy at least one of the following conditions: the temperature of the plastic flow portion resulting from friction stir welding is lower than the lower limit of the appropriate welding temperature for friction stir welding using a tool with no play, and the welding speed is higher than the upper limit of the appropriate welding speed for friction stir welding using a tool with no play.

17. The method for manufacturing a joining member as described in claim 16, wherein the friction stirring rotating member is configured so that, due to the play, the vibration of the pin portion during friction stirring has a larger amplitude and / or frequency than the output shaft.

18. The method for manufacturing a joining member described in claim 16 or 17, wherein the rotating member for friction stirring comprises a rotating shaft portion provided on the output shaft, and a tip portion configured to rotate by rotation transmitted from the rotating shaft portion and located on the tip side of the rotating shaft portion, the tip portion having the pin portion and a base end side portion provided on the base end side of the pin portion, or having a base end side portion not having the pin portion but configured to allow the pin portion to be detachably attached, the play is provided between the rotating shaft portion and the tip portion so as to enable vibration of the pin portion relative to the rotating shaft portion, and the rotating member for friction stirring is configured such that, due to the play, the vibration of the pin portion during friction stirring has a larger amplitude and / or frequency than the vibration of the rotating shaft portion.

19. A method for manufacturing a joining member as described in claim 18, wherein the pin portion has a surface contact portion at a height where it contacts the surface of the joined members, and the ratio of the diameter of the surface contact portion to the diameter of the pin portion adjacent to the surface contact portion closer to the tip than the surface contact portion is 1.8 or less, whereby the pin portion is configured to have a shoulder of a width small enough to satisfy said ratio, or to have no shoulder.

20. A method for manufacturing a joined member as described in any one of claims 16 to 19, wherein the friction stirring rotating member is configured so that vibration of the pin portion is passively generated by contact with the joined members undergoing plastic flow within the range of play.

21. A method for manufacturing a joining member as described in any one of claims 16 to 20, wherein the friction stirring rotating member is configured so that vibration of the pin portion occurs in at least one of the axial direction, circumferential direction, and radial direction of the pin portion due to the play.

22. A method for manufacturing a joined member as described in any one of claims 16 to 21, wherein the friction stirring rotating member is configured so that the pin portion is free or substantially free relative to the output shaft within the range of play.

23. A method for manufacturing a joint member according to any one of claims 16 to 22, wherein the play is a gap or substantially a gap.

24. A joining device for friction stir welding of members to be joined, comprising: a drive mechanism having an output shaft and configured to rotate the output shaft; and a pin portion configured to rotate by rotation transmitted from the drive mechanism and inserted into the members to be joined during friction stirring, the pin portion being configured to have play between the output shaft and the pin portion so as to enable vibration of the pin portion relative to the output shaft, and the drive mechanism being configured to perform friction stir welding by moving while rotating the pin portion so as to satisfy at least one of the following conditions: the temperature of a plastic flow portion resulting from friction stir welding is lower than the lower limit of an appropriate welding temperature for friction stir welding using a tool with no play, and the welding speed is higher than the upper limit of an appropriate welding speed for friction stir welding using a tool with no play.

25. The joining device according to claim 24, wherein the pin portion is configured such that, due to the play, vibration of the pin portion during friction stirring has an amplitude and / or frequency greater than vibration of the output shaft.

26. A method for manufacturing a welded member, in which an output shaft and a pin portion provided at the tip of the output shaft are rotated by rotation output from a drive mechanism, while the pin portion is inserted into members to be welded, thereby performing friction stir welding of the members to be welded, thereby manufacturing a welded member, wherein the pin portion is configured to have play between the output shaft and the pin portion so as to enable vibration of the pin portion relative to the output shaft, and the method includes a joining step of performing friction stir welding of the members to be welded by moving the pin portion while rotating it so as to satisfy at least one of the following conditions: the temperature of the plastic flow portion caused by friction stir welding is lower than the lower limit of the appropriate welding temperature for friction stir welding using a tool with no play, and the welding speed is higher than the upper limit of the appropriate welding speed for friction stir welding using a tool with no play.

27. A method for manufacturing a welded member in which a pin portion is inserted into workpieces while rotating with rotation output from a drive mechanism, thereby performing friction stir welding of the workpieces, wherein feedback control of the drive mechanism is performed so that the output of the drive mechanism changes in synchronization with or following the rotational fluctuation of the pin portion that occurs passively due to contact with the workpieces undergoing plastic flow, and friction stir welding is performed by moving the pin portion while rotating it so that at least one of the following conditions is satisfied: the temperature of the plastic flow portion caused by friction stir welding is lower than the lower limit of the appropriate welding temperature for friction stir welding without the feedback control, and the welding speed is higher than the upper limit of the appropriate welding speed for friction stir welding using a tool with no play.

28. A joined part manufactured by the manufacturing method according to any one of claims 16 to 23, 26 or 27, or by the joining apparatus according to claim 24 or 25.

29. The joining part according to claim 28, which is applied to any one of a vehicle including an automobile, a railway vehicle, an aircraft, a ship, and a rocket.

30. The joining part according to claim 28, which is applied to any one of an electrode part, an air conditioning device, a water-cooled or air-cooled power control unit, a water-cooled or air-cooled battery case, a door panel, a shock absorber, a suspension link, a waveguide, an antenna, a motor cover, a sake brewing tank, a vacuum device part, a sputtering target material, and an embedded heater.

31. The joined part according to any one of claims 28 to 30, which is a part manufactured by friction stir welding a plurality of plate materials of different thicknesses, or a part manufactured by friction stir welding a plurality of members made of different materials.

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