Friction stir spot welding device and method for operating same

Abstract

This friction stir spot welding device is provided with: a pin member (11); a shoulder piece (12); a rotary driver (57); a forward / backward actuator (53); and a controller (51) configured so as to operate the advance / retreat driver (53) and the rotation driver (57) such that the distal end of the shoulder member (12) in the rotating state reaches a predetermined first position within the second member (62), and so as to retreat the pin member (11) in the rotating state from the engaged part of the object (60) to be engaged.

Description

[0001] This application is a divisional application of the parent application whose applicant is "Kawasaki Heavy Industries, Ltd.", whose invention name is "Friction stirring point joining device and operation method thereof", and whose application number is "202080030715.5". Technical Field

[0002] The present invention relates to a friction stir spot joining device and a method for operating the same. Background Art

[0003] A method for joining different types of metal parts is known as follows: a first part made of soft metal and a second part made of hard metal are overlapped, and a probe is inserted from the first part side in a manner such that the tip reaches directly above the second part while rotating, thereby performing friction stirring to join the first and second parts (for example, see Patent Document 1).

[0004] In the method for joining different types of metal parts disclosed in Patent Document 1, a double-acting rotary tool is used as a rotary tool. The probe is independently constructed from a shoulder part and can move independently in the axial direction. The probe is inserted into the first part to perform friction stir welding of the first and second parts.

[0005] Patent Document 1: Japanese Patent No. 4937386

[0006] However, the method for joining dissimilar metal parts disclosed in Patent Document 1 still has room for improvement from the viewpoint of shortening the joining time. Summary of the invention

[0007] An object of the present invention is to provide a friction stir spot welding apparatus and an operating method thereof that can shorten the joining time compared to the method for joining dissimilar metal parts disclosed in Patent Document 1.

[0008] In order to solve the above-mentioned problems, the friction stirring spot joining device involved in the present invention utilizes friction heat to soften the objects to be joined having a first component and a second component to join, and the friction stirring spot joining device comprises: a pin component formed in a cylindrical shape; a shoulder component formed in a cylindrical shape and having the pin component inserted therein; a rotation driver which rotates the pin component and the shoulder component around an axis that coincides with the axis of the pin component; an advance and retreat driver which moves the pin component and the shoulder component forward and backward respectively along the axis; and a controller, wherein the first component is arranged to be opposite to the tool and is composed of a material with a lower melting point than the second component, and the controller is configured to execute: (A) The above-mentioned rotation drive and the above-mentioned advance and retreat drive are operated so that the above-mentioned pin component and the above-mentioned shoulder component press the engaged portion of the above-mentioned object to be engaged in a rotational state; (B) the above-mentioned advance and retreat drive and the above-mentioned rotation drive are operated so that the end of the above-mentioned shoulder component in a rotational state reaches a predetermined first position in the above-mentioned second component, and the above-mentioned pin component in a rotational state is retreated from the engaged portion of the above-mentioned object to be engaged; and (C) after the above-mentioned (B), the above-mentioned rotation drive and the above-mentioned advance and retreat drive are operated to pull out the above-mentioned shoulder component in a rotational state from the engaged portion of the above-mentioned object to be engaged, and the above-mentioned pin component in a rotational state is advanced toward the engaged portion of the above-mentioned object to be engaged.

[0009] Therefore, when the pin member and the shoulder member rotate at the same speed, the circumferential speed becomes larger when the shoulder member is pressed into the engaged portion than when the pin member is pressed into the engaged portion.

[0010] Therefore, when the shoulder component is pressed in, the force causing plastic flow in the joined portion becomes larger than when the pin component is pressed in, and the reduction in the pressing speed into the joined portion can be suppressed. Therefore, compared with the joining method of different types of metal components disclosed in the above-mentioned Patent Document 1, the joining time can be shortened.

[0011] In addition, the operating method of the friction stirring spot welding device involved in the present invention utilizes friction heat to soften the objects to be welded having the first component and the second component to weld, and the friction stirring spot welding device comprises: a pin component formed in a cylindrical shape; a shoulder component formed in a cylindrical shape and having the pin component inserted therein; a rotation driver which rotates the pin component and the shoulder component around an axis that coincides with the axis of the pin component; an advance and retreat driver which moves the pin component and the shoulder component forward and backward respectively along the axis; and a controller, wherein the first component is arranged to be opposite to the tool and is composed of a material with a lower melting point than the second component, and the controller is configured to execute: (A) The above-mentioned rotation drive and the above-mentioned advance and retreat drive are operated so that the above-mentioned pin component and the above-mentioned shoulder component press the engaged portion of the above-mentioned object to be engaged in a rotational state; (B) the above-mentioned advance and retreat drive and the above-mentioned rotation drive are operated so that the end of the above-mentioned shoulder component in a rotational state reaches a predetermined first position in the above-mentioned second component, and the above-mentioned pin component in a rotational state is retreated from the engaged portion of the above-mentioned object to be engaged; and (C) after the above-mentioned (B), the above-mentioned rotation drive and the above-mentioned advance and retreat drive are operated to pull out the above-mentioned shoulder component in a rotational state from the engaged portion of the above-mentioned object to be engaged, and the above-mentioned pin component in a rotational state is advanced toward the engaged portion of the above-mentioned object to be engaged.

[0012] Therefore, when the pin member and the shoulder member rotate at the same speed, the circumferential speed becomes larger when the shoulder member is pressed into the engaged portion than when the pin member is pressed into the engaged portion.

[0013] Therefore, when the shoulder component is pressed in, the force causing plastic flow in the joined portion becomes larger than when the pin component is pressed in, and the reduction in the pressing speed into the joined portion can be suppressed. Therefore, compared with the joining method of different types of metal components disclosed in the above-mentioned Patent Document 1, the joining time can be shortened.

[0014] The above objects, other objects, features and advantages of the present invention will become more apparent from the following detailed description of preferred embodiments with reference to the accompanying drawings.

[0015] According to the friction stir spot welding device and the operating method thereof according to the present invention, the welding time can be shortened compared with the conventional welding method of dissimilar metal parts. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram showing a schematic structure of the friction stir spot welding device according to the first embodiment.

[0017] Figure 2 It is schematically indicated Figure 1 A block diagram of the control structure of the friction stir spot joining device shown.

[0018] Figure 3 This is a flowchart showing an example of the operation of the friction stir spot welding device according to the first embodiment.

[0019] Figure 4A It is a schematic representation based on Figure 1 FIG. 1 is a process diagram showing an example of each process of friction stir spot welding by the friction stir spot welding device shown.

[0020] Figure 4B It is a schematic representation based on Figure 1 FIG. 1 is a process diagram showing an example of each process of friction stir spot welding by the friction stir spot welding device shown.

[0021] Figure 5 It is a graph showing the results of a tensile shear test and a cross tensile test of the workpieces subjected to friction stir spot welding under welding condition 1 using the friction stir spot welding apparatus of Comparative Example 1 and Test Example 1.

[0022] Figure 6 These are cross-sectional photographs of the workpieces that were friction stir spot welded under welding condition 1 using the friction stir spot welding apparatus of comparative example 1 and cross-sectional photographs of the workpieces that were friction stir spot welded under welding condition 2 using the friction stir spot welding apparatus of test example 1.

[0023] Figure 7 This is a graph showing the results of a tensile shear test of objects to be joined performed under joining conditions 3 to 7 using the friction stir spot welding apparatus of Test Example 2.

[0024] Figure 8 These are cross-sectional photographs of objects to be joined that were subjected to friction stir spot welding under joining conditions 3 to 7 using the friction stir spot welding apparatus of Test Example 2.

[0025] Fig. 9A It is a graph showing the results of a tensile shear test and a cross tensile test of the workpieces subjected to friction stir spot welding under welding condition 8 using the friction stir spot welding apparatus of Test Example 3.

[0026] Fig. 9B This is a cross-sectional photograph of the workpieces subjected to friction stir spot welding under welding condition 8 using the friction stir spot welding apparatus of Test Example 3.

[0027] Fig.10 This is a cross-sectional photograph of the workpieces subjected to friction stir spot welding under welding condition 9 using the friction stir spot welding apparatus of Test Example 4.

[0028] Fig.11These are cross-sectional photographs of objects to be joined that were subjected to friction stir spot welding under joining condition 10 using the friction stir spot welding apparatus of Comparative Example 2 and Test Example 5. DETAILED DESCRIPTION

[0029] Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. In addition, the same reference numerals are used throughout all the drawings to mark the same or equivalent elements, and their repeated descriptions are omitted. In addition, in all the drawings, there are cases where the structural elements required for explaining the present invention are taken out separately for illustration, and the illustrations for other structural elements are omitted. Furthermore, the present invention is not limited to the following embodiments.

[0030] (Implementation Method 1)

[0031] The friction stirring spot joining device involved in the present embodiment 1 is a friction stirring spot joining device that utilizes friction heat to soften the objects to be joined having the first component and the second component to join, and the friction stirring spot joining device comprises: a pin component formed in a cylindrical shape; a shoulder component formed in a cylindrical shape and having the pin component inserted therein; a rotation driver that rotates the pin component and the shoulder component around an axis that coincides with the axis of the pin component; an advance and retreat driver that moves the pin component and the shoulder component forward and backward respectively along the axis; and a controller, wherein the first component is arranged to be opposite to the tool and is composed of a material with a lower melting point than that of the second component, and the controller is configured The method is to execute: (A) actuating the rotation driver and the advance / retract driver so that the pin member and the shoulder member press the engaged portion of the object to be engaged in a rotational state; (B) actuating the advance / retract driver and the rotation driver so that the end of the shoulder member in the rotational state reaches a predetermined first position in the second member and the pin member in the rotational state retreats from the engaged portion of the object to be engaged; and (C) after (B), actuating the rotation driver and the advance / retract driver so as to pull the shoulder member in the rotational state out of the engaged portion of the object to be engaged and advance the pin member in the rotational state toward the engaged portion of the object to be engaged.

[0032] In the friction stir spot welding device according to the first embodiment, the first position may be any position within a range of 0.3 mm or less from the contact surface of the second member that contacts the first member.

[0033] In the friction stir spot welding device according to the first embodiment, the shoulder member may be configured so that when the radius of the distal end surface of the shoulder member is Rs and the radius of the distal end surface of the pin member is Rp, the following formula is satisfied: Rs>2 1 / 2 ×Rp.

[0034] Furthermore, in the friction stir spot welding apparatus according to the first embodiment, a sealing material may be applied to a contact portion between the overlapped first member and the second member of the workpiece.

[0035] Hereinafter, an example of the friction stir spot welding device according to the first embodiment will be described in detail with reference to the drawings.

[0036] [Structure of friction stir spot welding device]

[0037] Figure 1 : is a schematic diagram showing the schematic structure of the friction stir spot welding device involved in the present embodiment 1. In addition, Figure 1 In the figure, the up and down directions in the drawings are represented as the up and down directions of the friction stir spot welding device.

[0038] like Figure 1 As shown, the friction stir spot welding device 50 according to the first embodiment includes a pin member 11 , a shoulder member 12 , a tool holder 52 , an advance / retract actuator 53 , a clamping member 13 , a backing plate support 55 , a backing plate member 56 , and a rotation actuator 57 .

[0039] The pin member 11, the shoulder member 12, the tool holder 52, the forward and backward drive 53, the clamping member 13, and the rotation drive 57 are arranged at the upper end of the pad support portion 55 composed of a C-shaped frame (C-shaped frame). In addition, a pad member 56 is arranged at the lower end of the pad support portion 55. The pin member 11, the shoulder member 12, the clamping member 13 and the pad member 56 are mounted on the pad support portion 55 at positions facing each other. In addition, a workpiece 60 is arranged between the pin member 11, the shoulder member 12, the clamping member 13 and the pad member 56.

[0040] The pin member 11, the shoulder member 12, and the clamp member 13 are fixed to the tool holder 52 composed of a rotating tool holder 521 and a clamping holder 522. Specifically, the pin member 11 and the shoulder member 12 are fixed to the rotating tool holder 521, and the clamp member 13 is fixed to the clamping holder 522 via the clamping driver 41. Furthermore, the rotating tool holder 521 is supported by the clamping holder 522 via the rotating driver 57. In addition, the clamping driver 41 is composed of a spring.

[0041] The pin member 11 , the shoulder member 12 , and the clamping member 13 are driven by the advance / retract actuator 53 composed of the pin actuator 531 and the shoulder actuator 532 to advance / retract in the vertical direction.

[0042] The pin member 11 is formed in a cylindrical shape. Figure 1 Although not shown in detail, the pin member 11 is supported by the rotating tool holder 521. In addition, the pin member 11 is configured to rotate around the axis Xr (rotation axis) that coincides with the axis of the pin member 11 by the rotation driver 57, and can be rotated in the direction of the arrow P1, that is, the axis Xr direction ( Figure 1Move forward and backward (up and down directions).

[0043] In addition, the pin driver 531 may be constituted by a linear actuator, for example. The linear actuator may be constituted by a servomotor, a rack and a pinion, a servomotor and a ball screw, or an air cylinder, for example.

[0044] The shoulder member 12 is formed in a hollow cylindrical shape and is supported by the rotary tool holder 521. The pin member 11 is inserted into the hollow of the shoulder member 12. In other words, the shoulder member 12 is arranged so as to surround the outer peripheral surface of the pin member 11.

[0045] The shoulder member 12 is configured to rotate about the same axis Xr as the pin member 11 by the rotation driver 57 and to be movable forward and backward along the arrow P2 direction, that is, the axis Xr direction, by the shoulder driver 532 .

[0046] In addition, the shoulder driver 532 may be constituted by a linear actuator, for example. The linear actuator may be constituted by a servomotor, a rack and a pinion, a servomotor, a ball screw, or an air cylinder, for example.

[0047] Thus, the pin member 11 and the shoulder member 12 (rotating tool) are both supported by the same rotating tool holder 521 in this embodiment, and are both rotated integrally around the axis Xr by the rotating driver 57. Furthermore, the pin member 11 and the shoulder member 12 are configured to be able to move forward and backward along the axis Xr direction by the pin driver 531 and the shoulder driver 532, respectively.

[0048] In the first embodiment, the pin member 11 is configured to be independently movable forward and backward and to be movable forward and backward along with the movable forward and backward movement of the shoulder member 12 . However, the pin member 11 and the shoulder member 12 may be configured to be independently movable forward and backward.

[0049] Thus, the joining area (area of ​​newly formed surface) can be increased compared with the joining method of dissimilar metal parts disclosed in Patent Document 1. Therefore, the joining strength can be increased compared with the joining method of dissimilar metal parts disclosed in Patent Document 1.

[0050] The clamping member 13 is formed in a hollow cylindrical shape similarly to the shoulder member 12 , and is disposed so that the axis thereof coincides with the axis Xr. The shoulder member 12 is inserted into the hollow of the clamping member 13 .

[0051] That is, the cylindrical shoulder member 12 is arranged to surround the outer circumference of the pin member 11, and the cylindrical clamping member 13 is arranged to surround the outer circumference of the shoulder member 12. In other words, the clamping member 13, the shoulder member 12, and the pin member 11 have a coaxial nested structure.

[0052] In addition, the clamping member 13 is configured to press the object 60 from one side (surface). As described above, in the present embodiment 1, the clamping member 13 is supported by the clamping fixture 522 via the clamping driver 41. The clamping driver 41 is configured to apply force to the clamping member 13 toward the pad member 56 side. Moreover, the clamping member 13 (including the clamping driver 41 and the clamping fixture 522) is configured to be able to move forward and backward in the arrow P3 direction (the same direction as the arrow P1 and the arrow P2) through the shoulder driver 532.

[0053] In the first embodiment, the clamp actuator 41 is composed of a spring, but the present invention is not limited thereto. The clamp actuator 41 may be configured to apply a biasing force or a pressing force to the clamp member 13, and for example, a mechanism using air pressure, hydraulic pressure, a servomotor, etc. may be used as appropriate.

[0054] The pin member 11, the shoulder member 12 and the clamping member 13 respectively have a terminal end face 11a, a terminal end face 12a and a terminal end face 13a. In addition, the pin member 11, the shoulder member 12 and the clamping member 13 are moved forward and backward by the forward and backward drive 53, so that the terminal end face 11a, the terminal end face 12a and the terminal end face 13a respectively contact the surface of the object 60 to be joined (the joined portion of the object 60 to be joined), and the object 60 to be joined is pressed.

[0055] The shoulder member 12 is configured so that, when the radius of the distal end surface 12a of the shoulder member 12 is Rs and the radius of the distal end surface 11a of the pin member 11 is Rp, Rs>2 1 / 2 ×Rp. In other words, the shoulder member 12 is configured such that the area of ​​the annular distal end surface 12 a is larger than the area of ​​the circular distal end surface 11 a of the pin member 11 .

[0056] Thus, the joining area (area of ​​newly formed surface) can be increased compared with the joining method of dissimilar metal parts disclosed in Patent Document 1. Therefore, the joining strength can be increased compared with the joining method of dissimilar metal parts disclosed in Patent Document 1.

[0057] In the present embodiment 1, the pad member 56 is configured to be supported by a flat surface (support surface 56a) in a manner that abuts against the back surface of the flat plate-shaped object to be joined 60. The pad member 56 has no particular limitation on its structure as long as it can properly support the object to be joined 60 in a manner that enables friction stir joining. The pad member 56 may also be configured such that, for example, pad members 56 having various shapes are separately prepared and removed from the pad support portion 55 according to the type of the object to be joined 60, and can be replaced.

[0058] The object to be bonded 60 has two plate-shaped first members 61 and second members 62. The first member 61 is disposed to face the pin member 11 and the shoulder member 12, and is made of a material having a lower melting point than the second member 62.

[0059] In addition, the object to be bonded 60 may be coated with a sealing material at the contact portion between the overlapped first component 61 and the second component 62. The sealing material may be a sealant or an adhesive. For example, a synthetic rubber such as polysulfide-based synthetic rubber, natural rubber, silicone rubber, fluorine rubber, or a synthetic resin such as tetrafluoroethylene rubber resin may be used as the sealing material.

[0060] At least one of metal materials (e.g., aluminum, aluminum alloy, magnesium alloy, etc.), thermoplastics (e.g., polyamide, etc.), and fiber-reinforced plastics (e.g., carbon fiber-reinforced plastic, etc.) can be used as the first member 61. Various aluminum alloys can be used as the aluminum alloy, for example, Al-Mg-Si alloy (A6061) can be used, and Al-Si-Mg alloy (AC4C) can also be used.

[0061] In addition, as the second component 62, a metal material (such as steel, titanium, etc.) can be used. As the steel, various steels can be used, and soft steel or high-tensile steel can be used. In addition, an oxide film can be formed on the surface of the steel, and a plating layer (such as galvanizing) can also be formed. As the steel plate formed with galvanizing, it can be a hot-dip galvanized steel plate (GI steel plate), it can also be an alloyed hot-dip galvanized steel plate (GA steel plate), it can also be an aluminum-zinc-plated steel plate (Galvalume), or it can be an aluminum-silicon-plated hot stamped steel plate. In addition, the thickness of the plating layer can be 2μm to 50μm.

[0062] In addition, in the present embodiment 1, the object 60 is formed by a plate-like first component 61 and a plate-like second component 62, but the object 60 is not limited thereto. The shape of the object 60 (the first component 61 and the second component 62) is arbitrary, for example, it can be a rectangular parallelepiped or can be formed into an arc shape. In addition, the object 60 can also have more than three components.

[0063] In addition, the specific structures of the pin member 11, the shoulder member 12, the tool holder 52, the advance and retreat driver 53, the clamping member 13, the pad support portion 55, and the rotation driver 57 of the present embodiment 1 are not limited to the above-mentioned structures, but can be widely used in the field of friction stir welding. For example, the pin driver 531 and the shoulder driver 532 can also be composed of a motor and a gear mechanism known in the field of friction stir welding.

[0064] In the first embodiment, the pad support portion 55 is composed of a C-shaped frame, but the present invention is not limited thereto. The pad support portion 55 may be constructed in any manner as long as it can support the pin member 11, the shoulder member 12, and the clamping member 13 so as to be able to move forward and backward and can support the pad member 56 at a position opposite to the pin member 11, the shoulder member 12, and the clamping member 13.

[0065] In the first embodiment, the structure including the clamping member 13 is adopted, but the present invention is not limited to this and a structure without the clamping member 13 may be adopted. In this case, for example, the clamping member 13 is configured to be detachable from the pad support portion 55 as required.

[0066] The friction stir spot welding device 50 according to the first embodiment is provided in a friction stir spot welding robot (not shown). Specifically, the pad support portion 55 is attached to the distal end of the arm of the robot.

[0067] Therefore, the pad support 55 can be considered to be included in the friction stir spot welding robot. The specific structure of the friction stir spot welding robot including the pad support 55 and the arm is not particularly limited, and a structure known in the field of friction stir welding such as a multi-joint robot can be appropriately used.

[0068] In addition, the friction stir spot welding device 50 (including the pad support portion 55) is not limited to the case of being applied to a robot device for friction stir spot welding, for example, it can also be appropriately used in well-known processing equipment such as NC machine tools, large C frames and automatic riveting machines.

[0069] In addition, the friction stir spot welding device 50 according to the first embodiment may be configured such that two or more pairs of robots make the portion of the friction stir spot welding device 50 other than the backing plate member 56 face the backing plate member 56. Furthermore, as long as the friction stir spot welding device 50 can stably perform friction stir spot welding on the objects 60, the objects 60 may be handheld, or a robot may be used as a positioner for the objects 60.

[0070] [Control structure of friction stir spot welding device]

[0071] Next, refer to Figure 2 The control structure of the friction stirring spot welding device 50 according to the first embodiment will be specifically described.

[0072] Figure 2 It is schematically indicated Figure 1 A block diagram of the control structure of the friction stir spot joining device shown.

[0073] like Figure 2 As shown, the friction stir spot welding device 50 includes a controller 51 , a memory 31 , an input device 32 , and a position detector 33 .

[0074] The controller 51 is configured to control each component (each device) constituting the friction stirring spot welding device 50. Specifically, the controller 51 controls the pin driver 531 and the shoulder driver 532 and the rotation driver 57 constituting the advance and retreat driver 53 by reading and executing software such as a basic program stored in the memory.

[0075] Thus, it is possible to control the switching of the forward movement or the backward movement of the pin member 11 and the shoulder member 12, the control of the terminal positions of the pin member 11 and the shoulder member 12 during the forward and backward movement, the movement speed and the movement direction, etc. In addition, it is possible to control the pressing force of the pin member 11, the shoulder member 12 and the clamping member 13 pressing the object 60. Furthermore, it is possible to control the rotation speed of the pin member 11 and the shoulder member 12.

[0076] The controller 51 may be a single controller 51 for centralized control or a plurality of controllers 51 for distributed control in cooperation with each other. The controller 51 may be a microcomputer or an MPU, a PLC (Programmable Logic Controller), a logic circuit, or the like.

[0077] The memory 31 stores basic programs and various data in a readable manner, and the memory 31 is composed of a known memory, a hard disk, and other storage devices. The memory 31 does not need to be a single memory, and can also be composed of multiple storage devices (such as random access memory and hard disk drive). In the case where the controller 51 is composed of a microcomputer, at least a part of the memory 31 can be composed as an internal memory of the microcomputer, or can be composed as an independent memory.

[0078] It goes without saying that data is stored in the memory 31 , and that the memory 31 may be configured so that data can be read from a device other than the controller 51 , or may be configured so that data can be written from the controller 51 or the like.

[0079] The input device 32 can input various parameters or other data related to the control of the friction stirring point joining to the controller 51, and is composed of a well-known input device such as a keyboard, a touch panel, a button switch group, etc. In the present embodiment 1, at least the joining conditions of the object 60 to be joined, such as the thickness and material of the object 60 to be joined, can be input by the input device 32.

[0080] The position detector 33 is configured to detect the position information of the end (end surface 12a) of the shoulder component 12, and output the detected position information to the controller 51. As the position detector 33, for example, a displacement sensor, an LVDT, an encoder, etc. can be used. In the case of using an encoder as the position detector 33, the encoder can be configured to detect the rotation angle of the advance / retract driver 53 (shoulder driver 532) that drives the shoulder component 12 to advance and retreat. In addition, as the position detector 33, an ammeter that detects the current value supplied to the advance / retract driver 53 (shoulder driver 532) that drives the shoulder component 12 to advance and retreat can also be used.

[0081] [Operation of the friction stir spot welding device (operation method)]

[0082] Next, refer to Figure 3 , Figure 4A as well as Figure 4B The operation of the friction stirring spot welding device 50 according to the first embodiment will be described in detail. Figure 4A as well as Figure 4B In the embodiment, a case where the first member 61 and the second member 62 are used as the objects to be joined 60 and are overlapped and connected by point joining is cited as an example.

[0083] Figure 3 This is a flowchart showing an example of the operation of the friction stir spot welding device according to the first embodiment. Figure 4A as well as Figure 4B It is a schematic representation based on Figure 1 FIG. 1 is a process diagram showing an example of each process of friction stir spot welding by the friction stir spot welding device shown.

[0084] also, Figure 4A as well as Figure 4B In the figure, a part of the friction stir spot welding device is omitted, and the arrow r indicates the rotation direction of the pin member 11 and the shoulder member 12, and the thick arrow F indicates the direction of the force applied to the first member 61 and the second member 62. In addition, the backing plate member 56 also applies force to the first member 61 and the second member 62, but for the convenience of explanation, Figure 4A as well as Figure 4B Furthermore, the shoulder member 12 is cross-hatched to clearly distinguish it from the pin member 11 and the clamping member 13 .

[0085] First, the worker (operator) places the workpiece 60 on the support surface 56a of the backing member 56. Then, the worker operates the input device 32 to input the execution of joining the workpiece 60 to the controller 51. Alternatively, the workpiece 60 may be placed on the support surface 56a of the backing member 56 by a robot.

[0086] In this way, Figure 3 As shown, the controller 51 drives the rotation driver 57 to rotate the pin member 11 and the shoulder member 12 at a predetermined first rotation speed (for example, 200 to 3000 rpm) (step S101; see Figure 4A process (1)).

[0087] Next, the controller 51 drives the advance / retract drive 53 (shoulder drive 532) to move the pin member 11, the shoulder member 12, and the clamping member 13 toward the object 60 while the pin member 11 and the shoulder member 12 are rotating, so that the end surface 11a of the pin member 11, the end surface 12a of the shoulder member 12, and the end surface 13a of the clamping member 13 ( Figure 4A as well as Figure 4B ) approaches the surface 60c of the object 60 to be bonded (the bonded portion of the object 60 to be bonded) (step S102; see Figure 4A process (2)).

[0088] At this time, the controller 51 controls the advance and retreat driver 53 (shoulder driver 532) so that the pin component 11, the shoulder component 12 and the clamping component 13 press the object 60 with a predetermined pressing force (for example, a predetermined value within the range of 3 kN to 15 kN).

[0089] Thus, the first member 61 and the second member 62 are sandwiched between the clamping member 13 and the backing member 56 , and the clamping member 13 is urged toward the surface 60 c of the object 60 by the contraction of the clamping actuator 41 , thereby generating a clamping force.

[0090] In addition, in this state, since the first member 61 does not move forward and backward together with the pin member 11 and the shoulder member 12, it is equivalent to "preliminary heating" of the surface 60c of the object 60 to be joined. As a result, the constituent material in the contact area of ​​the first member 61 softens due to frictional heat, and a plastic flow portion 60a is generated near the surface 60c of the object 60 to be joined.

[0091] Next, the controller 51 drives the advance and retreat driver 53 so that the end surface 11a of the pin member 11 is sunk relative to the end surface 12a of the shoulder member 12 (step S103). At this time, the controller 51 can drive the advance and retreat driver 53 (pin driver 531) so that the pin member 11 is separated from the object 60. In addition, the controller 51 can also drive the advance and retreat driver 53 (shoulder driver 532) so that the shoulder member 12 is pressed into the object 60.

[0092] Thereby, the tip end portion of the shoulder member 12 is pressed into the joined portion of the joined object 60 in a rotated state.

[0093] Next, the controller 51 acquires the position information of the end of the shoulder member 12 from the position detector 33 (step S104). Next, the controller 51 determines whether the position information of the end of the shoulder member 12 acquired in step S104 reaches a predetermined first position (step S105).

[0094] Here, the first position can be set in advance by experiments or the like, and is any position in the second member 62. More specifically, the first position is any position within a range of 0.3 mm or less from the contact surface 62a of the second member 62 that contacts the first member 61.

[0095] In addition, from the viewpoint of removing the plating layer (plating film) or the oxide film formed on the second member 62 to form a new surface, the first position may be a position of 0.008 mm or more from the contact surface 62a, or a position of 0.01 mm or more from the contact surface 62a. In addition, from the viewpoint of suppressing the wear (damage) of the shoulder member 12, the first position may be a position of 0.25 mm or less from the contact surface 62a, or a position of 0.20 mm or less from the contact surface 62a, or a position of 0.10 mm or less from the contact surface 62a.

[0096] Furthermore, from the perspective of removing the plating layer (plating film) or the oxide film formed on the second part 62 to form a new surface, the first position can be a position below 0.20 mm from the plating layer (plating film) or the oxide film formed on the second part 62, or it can be a position below 0.10 mm from the plating layer (plating film) or the oxide film formed on the second part 62.

[0097] Thus, the end surface 12a of the shoulder member 12 reaches any position (i.e., the first position) within 0.3 mm from the contact surface 62a of the second member 62. Thus, a new surface is formed at the portion of the second member 62 contacting the shoulder member 12 and / or the portion of the second member 62 contacting the plastic flow portion 60a.

[0098] In addition, since the softened material of the plastic flow portion 60a is pushed away by the shoulder member 12 and flows from directly below the shoulder member 12 to directly below the pin member 11, the pin member 11 retreats and floats relative to the shoulder member 12 (see FIG. Figure 4A process (3)).

[0099] Impurities (such as zinc and iron oxide) formed in the plating layer (plating film) or oxide film formed on the surface of the second member 62 also flow directly below the pin member 11. In addition, some of the impurities flow outward from the outer peripheral surface of the distal end of the shoulder member 12.

[0100] When the controller 51 determines that the position information of the end of the shoulder part 12 obtained in step S104 has not reached the first position (No in step S105), the controller 51 returns to step S104 and repeats the processing of steps S104 and S105 until it is determined that the position information of the end of the shoulder part 12 obtained in step S104 has reached the first position.

[0101] On the other hand, when the controller 51 determines that the position information of the distal end of the shoulder member 12 acquired in step S104 has reached the first position (yes in step S105 ), the controller 51 executes the process of step S106 .

[0102] Furthermore, when the position detector 33 is constituted by a displacement sensor, the controller 51 may determine whether or not the first position has been reached based on the position information of the tip of the shoulder member 12 detected by the displacement sensor.

[0103] In addition, when the position detector 33 is composed of an encoder that detects the rotation angle of the advance / retract actuator 53 (shoulder actuator 532) that drives the shoulder member 12 to advance and retract, the controller 51 can also determine whether the first position is reached as follows.

[0104] The controller 51 may determine that the distal end of the shoulder member 12 has reached the first position when the rotation angle information (speed information) detected by the encoder as the position detector 33 becomes smaller than a predetermined first angle set in advance.

[0105] Here, the first angle can be set in advance through experiments or the like. For example, when the material constituting the second component 62 is harder than the material constituting the first component 61, if the end of the shoulder component 12 reaches the surface of the second component 62, the travel speed of the shoulder component 12 decreases. Therefore, the first angle may also be the angle information input to the forward and backward driver 53 (shoulder driver 532). In addition, the first angle may also be the angle information detected by the encoder last time (immediately before) during the execution of the joining process.

[0106] In addition, when the position detector 33 is composed of an ammeter that detects the current value supplied to the advance / retract actuator 53 (shoulder actuator 532) that drives the shoulder member 12 to advance and retract, the controller 51 can also determine whether the first position is reached as follows.

[0107] The controller 51 may determine that the distal end of the shoulder member 12 has reached the first position when the current value information detected by the ammeter as the position detector 33 becomes smaller than a predetermined first current value set in advance.

[0108] Here, the first current value can be set by a preliminary experiment or the like. For example, when the material constituting the second component 62 is harder than the material constituting the first component 61, if the end of the shoulder component 12 reaches the surface of the second component 62, the travel speed of the shoulder component 12 decreases. Therefore, the first current value may also be the current value information input to the advance and retreat driver 53 (shoulder driver 532). In addition, the first current value may also be the current value information detected by the ammeter last time (immediately before) during the execution of the joining process.

[0109] In step S106 , the controller 51 drives the advance / retract driver 53 (pin driver 531 ) to move the pin member 11 toward the object 60 , and / or drives the advance / retract driver 53 (shoulder driver 532 ) to move the shoulder member 12 away from the object 60 .

[0110] Specifically, the controller 51 controls the forward and backward actuator 53 so that the distal end surface 11 a of the pin member 11 and the distal end surface 12 a of the shoulder member 12 are aligned (coplanar) to such an extent that there is almost no height difference between them.

[0111] As a result, the pin member 11 advances toward the first member 61, and the shoulder member 12 retreats from the first member 61. At this time, the softened portion of the plastic flow portion 60a flows from just below the pin member 11 to just below the shoulder member 12 (the recessed portion created by the press fit of the shoulder member 12).

[0112] Then, the distal end surface 11a of the pin member 11 and the distal end surface 12a of the shoulder member 12 are moved to the vicinity of the surface 60c of the object 60 to be bonded. Thus, the surface 60c of the object 60 to be bonded is shaped to obtain a substantially flat surface with no substantial recess (see Figure 4B process (4)).

[0113] In addition, the controller 51 preferably controls the advance / retract drive 53 in the processing of step S103 and / or step S106 so that when the area of ​​the end surface of the pin member 11 is set to Ap, the area of ​​the end surface of the shoulder member 12 is set to As, the pressing depth of the pin member 11 is set to Pp, and the pressing depth of the shoulder member 12 is set to Ps, the following formula (I) is used:

[0114] Ap·Pp+As·Ps=Tx···(I)

[0115] The absolute value of the defined tool average position Tx becomes smaller, and it is more preferable to control the advance / retract drive 53 so that the tool average position becomes Tx = 0. The specific control for reducing the absolute value of the tool average position Tx is disclosed in detail in Japanese Patent Application Laid-Open No. 2012-196682, and therefore, the description thereof is omitted here.

[0116] In addition, the controller 51 may also control the advance / retract drive 53 in the process of step S106 so that the end face 11a of the pin member 11 is located at the first position. In this case, the controller 51 may also control the advance / retract drive 53 so that after the end face 11a of the pin member 11 is located at the first position, the end face 11a of the pin member 11 and the end face 12a of the shoulder member 12 become coplanar.

[0117] Next, the controller 51 drives the advance and retreat driver 53 to separate the pin member 11, the shoulder member 12, and the clamping member 13 from the object 60 (step S107). Next, the controller 51 controls the rotation driver 57 to stop the rotation of the pin member 11 and the shoulder member 12 (step S108; see Figure 4B Step (5)) ends this procedure (the step of joining the object 60).

[0118] Thus, the rotation (and pressure) generated by the abutment between the pin component 11 and the shoulder component 12 is no longer applied to the first component 61 and the second component 62, so the plastic flow stops in the plastic flow portion 60a, and the plastic flow portion 60a is bonded to the new surface of the second component 62.

[0119] In the friction stirring point welding device 50 involved in the present embodiment 1 constructed in this way, the controller 51 is configured to operate the advance and retreat driver 53 and the rotation driver 57 so that the end of the shoulder component 12 in a rotating state reaches the first position and the pin component 11 in a rotating state retreats from the joined portion of the object 60 to be joined.

[0120] Therefore, when the pin member 11 and the shoulder member 12 rotate at the same speed, the circumferential speed becomes larger when the shoulder member 12 is pressed into the joined portion than when the pin member 11 is pressed into the joined portion.

[0121] Therefore, when the shoulder member 12 is pressed in, the force causing plastic flow in the joined portion becomes larger than when the pin member 11 is pressed in, and the reduction in the pressing speed into the joined portion can be suppressed. Therefore, in the friction stirring spot joining device 50 involved in the first embodiment, the joining time can be shortened compared with the joining method of different types of metal parts disclosed in the above-mentioned patent document 1.

[0122] In the friction stirring spot welding device 50 according to the first embodiment, the controller 51 is configured to operate the advance / retract drive 53 so that the tip of the shoulder member 12 reaches any position (i.e., the first position) less than 0.3 mm from the surface of the second member 62 .

[0123] As a result, the tip end surface of the shoulder member 12 abuts against the second member 62 in a rotated state, so that a new surface is formed earlier than the method for joining dissimilar metal parts disclosed in the above-mentioned Patent Document 1. Therefore, in the friction stirring spot joining device 50 involved in the present embodiment 1, the joining time can be shortened compared with the method for joining dissimilar metal parts disclosed in the above-mentioned Patent Document 1.

[0124] Furthermore, the controller 51 controls the distal end of the shoulder member 12 to reach the first position, thereby removing the plating layer (plating film) or oxide film formed on the surface of the second member 62 by the distal end of the shoulder member 12 to form a new surface.

[0125] Impurities (such as zinc) forming the removed plating layer (plating film) or oxide film flow directly below the pin member 11. Part of the impurities also flow outward from the outer peripheral surface of the tip of the shoulder member 12.

[0126] Therefore, when the softened portion of the plastic flow portion 60a flows from directly below the pin part 11 to directly below the shoulder part 12 (the recess created by the pressing of the shoulder part 12), the amount of impurities flowing directly below the shoulder part 12 is reduced by an amount corresponding to the impurities flowing out.

[0127] On the other hand, in the method for joining different types of metal parts disclosed in the above-mentioned Patent Document 1, since the probe (pin part) is pressed in, the softened part (plastic flow part 60a) of the object to be joined 60 is pushed away by the probe, and flows from directly below the probe to directly below the shoulder part, and the shoulder part moves upward relative to the probe. At this time, impurities (such as zinc, etc.) formed in the plating layer (plating film) or oxide film formed on the surface of the second part 62 also flow directly below the shoulder part.

[0128] Furthermore, since the shoulder member moves upward, the softened portion of the plastic flow portion 60 a and impurities hardly flow out to the outside of the outer peripheral surface of the terminal end portion of the shoulder member.

[0129] Therefore, when the softened portion of the plastic flow portion 60a flows from just below the shoulder member to just below the probe (a recessed portion created by the pressing of the probe), the amount of impurities flowing just below the probe does not decrease.

[0130] Therefore, in the friction stirring spot welding device 50 involved in this embodiment 1, compared with the joining method of different types of metal parts disclosed in the above-mentioned Patent Document 1, the amount of impurities in the part abutting against the new surface (the recessed part generated by pressing the shoulder part 12) can be reduced.

[0131] Therefore, the friction stirring spot welding device 50 according to the first embodiment can increase the joining strength compared with the method for joining dissimilar metal members disclosed in Patent Document 1.

[0132] In the friction stir spot welding device 50 according to the first embodiment, the shoulder member 12 is configured so that when the radius of the distal end surface 12a of the shoulder member 12 is Rs and the radius of the distal end surface 11a of the pin member 11 is Rp, Rs>2 1 / 2 ×Rp. In other words, the shoulder member 12 is configured such that the area of ​​the annular distal end surface 12 a is larger than the area of ​​the circular distal end surface 11 a of the pin member 11 .

[0133] Thus, the joining area (the area of ​​the newly formed surface) can be increased compared to the joining method of dissimilar metal parts disclosed in the above-mentioned Patent Document 1. Therefore, in the friction stirring spot joining device 50 involved in the present embodiment 1, the joining strength can be increased compared to the joining method of dissimilar metal parts disclosed in the above-mentioned Patent Document 1.

[0134] [Test example]

[0135] Next, a joining test of the workpiece 60 using the friction stir spot welding apparatus 50 according to the first embodiment and the method for joining dissimilar metal members disclosed in Patent Document 1 will be described.

[0136] (Test Example 1)

[0137] A joining test of the workpiece 60 was performed using the friction stir spot joining device 50 according to the first embodiment. The first position, which is the target arrival position of the shoulder member 12, was set to a position 0.05 mm downward from the contact surface (upper surface) of the second member 62 that contacts the first member 61.

[0138] (Comparative Example 1)

[0139] As Comparative Example 1, a joining test of an object to be joined 60 based on the joining method of dissimilar metal members disclosed in Patent Document 1 was performed.

[0140] Specifically, the friction stirring spot welding apparatus 50 according to the first embodiment is used, and a program is set in the process of step S103 to drive the pin driver 531 to press the pin member 11 into the joined portion. At this time, the program is set so that the tip of the pin member 11 is located 0.1 mm above the contact surface (lower surface) of the first member 61 that contacts the second member 62.

[0141] In addition, in the process of step S106 , a program is set to drive the advance / retract driver 53 (pin driver 531 ) so that the pin member 11 is separated from the object 60 .

[0142] (Joining condition 1)

[0143] A 1 mm aluminum plate (A6061) was used as the first member 61, and a 0.7 mm 270 MPa grade non-plated steel plate was used as the second member 62. The first rotation speed of the pin member 11 and the shoulder member 12 was set to 1000 rpm.

[0144] Furthermore, the objects 60 to be joined that were joined by the friction stir spot welding apparatuses of Comparative Example 1 and Test Example 1 were subjected to a tensile shear test (JIS Z 3136) and a cross tensile test (JIS Z 3137), respectively.

[0145] (Joining condition 2)

[0146] A 3 mm aluminum plate (A6061) was used as the first member 61, and a 0.7 mm 270 MPa grade non-plated steel plate was used as the second member 62. The first rotation speed of the pin member 11 and the shoulder member 12 was set to 1000 rpm.

[0147] (Test result 1)

[0148] Figure 5 It is a graph showing the results of a tensile shear test and a cross tensile test of the workpieces subjected to friction stir spot welding under welding condition 1 using the friction stir spot welding apparatus of Comparative Example 1 and Test Example 1.

[0149] in addition, Figure 6 These are cross-sectional photographs of the workpieces that were friction stir point welded under welding condition 1 using the friction stir point welding apparatus of comparative example 1, and cross-sectional photographs of the workpieces that were friction stir point welded under welding condition 1 and welding condition 2 using the friction stir point welding apparatus of test example 1.

[0150] like Figure 5 As shown, the tensile shear strength of the workpiece 60 subjected to friction stir point welding under welding condition 1 using the friction stir point welding apparatus of comparative example 1 was 1345 N, and the cross tensile strength was 84 N. On the other hand, the tensile shear strength of the workpiece 60 subjected to friction stir point welding under welding condition 1 using the friction stir point welding apparatus of test example 1 was 3381 N, and the cross tensile strength was 1219 N.

[0151] These results show that the friction stir spot welding device 50 according to the first embodiment can achieve sufficiently high joining strength compared with the method for joining dissimilar metal members disclosed in Patent Document 1.

[0152] In addition, if Figure 6 As shown, even if the thickness of the first member 61 of the object to be joined 60 is increased to 3 mm, it can be made to sufficiently plastically flow, and the first member 61 and the second member 62 can be joined.

[0153] (Test Example 2)

[0154] The friction stirring spot welding device 50 according to the first embodiment was used to perform welding tests on various welded objects 60. The first position, which is the target arrival position of the shoulder member 12, was set to a position 0.05 mm downward from the contact surface (upper surface) of the second member 62 that contacts the first member 61.

[0155] (Joining condition 3)

[0156] A 1 mm aluminum plate (A6061) was used as the first member 61, and a 0.7 mm 270 MPa grade non-plated steel plate was used as the second member 62. The first rotation speed of the pin member 11 and the shoulder member 12 was set to 1000 rpm.

[0157] (Joining condition 4)

[0158] A 1 mm aluminum plate (A6061) was used as the first member 61, and a 1.2 mm 270 MPa grade hot-dip galvanized steel plate (GI) was used as the second member 62. The first rotation speed of the pin member 11 and the shoulder member 12 was set to 1000 rpm.

[0159] (Joining condition 5)

[0160] A 1 mm aluminum plate (A6061) was used as the first member 61, and a 1.2 mm 270 MPa grade alloyed hot-dip galvannealed steel plate (GA) was used as the second member 62. The first rotation speed of the pin member 11 and the shoulder member 12 was set to 1500 rpm.

[0161] (Joining Condition 6)

[0162] A 1 mm aluminum plate (A6061) was used as the first member 61, and a 1.2 mm 980 MPa grade non-plated steel plate was used as the second member 62. The first rotation speed of the pin member 11 and the shoulder member 12 was set to 2000 rpm.

[0163] (Joining Condition 7)

[0164] A 1 mm aluminum plate (A6061) was used as the first member 61, and a 1.2 mm 980 MPa grade alloyed hot-dip galvannealed steel plate (GA) was used as the second member 62. The first rotation speed of the pin member 11 and the shoulder member 12 was set to 2000 rpm.

[0165] Then, a tensile shear test (JIS Z 3136) was performed on each of the objects 60 joined by the friction stir spot welding apparatus of Test Example 3.

[0166] (Test result 2)

[0167] Figure 7 This is a graph showing the results of a tensile shear test of objects to be joined performed under joining conditions 3 to 7 using the friction stir spot welding apparatus of Test Example 2.

[0168] in addition, Figure 8 These are cross-sectional photographs of objects to be joined that were subjected to friction stir spot welding under joining conditions 3 to 7 using the friction stir spot welding apparatus of Test Example 2.

[0169] like Figure 7 as well as Figure 8 As shown, the tensile shear strength of the workpiece 60 subjected to friction stir spot welding under welding conditions 3 to 6 using the friction stir spot welding apparatus of Test Example 2 was 3.0 kN or more, and the welding strength was sufficiently high even when various steel plates were used.

[0170] In addition, the inventors have confirmed that a 1 mm aluminum plate (A6061) was used as the first component 61, an aluminum-silicon-plated hot-stamped steel plate was used as the second component 62, and the first rotation speed was set to 2000 rpm to perform a joining test on the object 60 to be joined. The result showed that the object 60 to be joined was able to be joined (data not shown).

[0171] (Test Example 3)

[0172] A joining test of the workpiece 60 was performed using the friction stirring spot joining device 50 according to the first embodiment. The first position, which is the target arrival position of the shoulder member 12, was set to a position 0.2 mm downward from the contact surface (upper surface) of the second member 62 that contacts the first member 61.

[0173] (Joining Condition 8)

[0174] A 2.5 mm Al-Si-Mg alloy (AC4C) was used as the first member 61, and a 270 MPa class non-plated steel plate was used as the second member 62. The first rotation speed of the pin member 11 and the shoulder member 12 was set to 1500 rpm.

[0175] Then, the objects to be joined 60 joined by the friction stir spot welding apparatus of Test Example 3 were subjected to a tensile shear test (JIS Z 3136) and a cross tensile test (JIS Z 3137).

[0176] (Test result 3)

[0177] Fig. 9A This is a graph showing the results of a tensile shear test and a cross tensile test of a workpiece subjected to friction stir spot welding under welding condition 8 using the friction stir spot welding apparatus of test example 3. Fig. 9B This is a cross-sectional photograph of the workpieces subjected to friction stir spot welding under welding condition 8 using the friction stir spot welding apparatus of Test Example 3.

[0178] like Fig. 9A as well as Fig. 9B As shown, it is shown that even if the Al—Si—Mg alloy (AC4C) is used as the first member 61, the workpiece 60 can be joined with sufficient joining strength.

[0179] (Test Example 4)

[0180] A joining test of the workpiece 60 was performed using the friction stirring spot joining device 50 according to the first embodiment. The first position, which is the target arrival position of the shoulder member 12, was set to a position 0.1 mm below the contact surface (upper surface) of the second member 62 that contacts the first member 61. In addition, a sealing material (adhesive) was applied to the contact surface between the first member 61 and the second member 62.

[0181] (Joining Condition 9)

[0182] A 1 mm aluminum plate (A6061) was used as the first member 61, and a 0.7 mm 270 MPa grade non-plated steel plate was used as the second member 62. The first rotation speed of the pin member 11 and the shoulder member 12 was set to 1000 rpm.

[0183] (Test result 4)

[0184] Fig.10 This is a cross-sectional photograph of the workpieces that were subjected to friction stir spot welding under welding condition 9 using the friction stir spot welding apparatus of Test Example 4. Fig.10The joining range shown is a portion where the pin member 11 and the shoulder member 12 come into contact with the upper surface of the object 60 to be joined.

[0185] like Fig.10 As shown, a large amount of the sealing material (adhesive) applied to the contact surfaces of the first member 61 and the second member 62 is present just below the pin member 11 .

[0186] Therefore, the following inspiration is obtained: by executing step S106, even if the softened part of the plastic flow portion 60a flows from directly below the pin part 11 to directly below the shoulder part 12 (the recessed portion created by the pressing of the shoulder part 12), the sealing material does not flow directly below the shoulder part 12 (the recessed portion created by the pressing of the shoulder part 12), but remains (retained) directly below the pin part 11.

[0187] (Test Example 5)

[0188] The joining test of the workpiece 60 was performed using the friction stirring spot joining device 50 according to the first embodiment. The first position, which is the target arrival position of the shoulder member 12, was set to a position 0.1 mm downward from the contact surface (upper surface) of the second member 62 that contacts the first member 61. In addition, when the end of the shoulder member 12 reaches the first position in step S105, the pin member 11 and the shoulder member 12 are pulled upward to stop the joining test.

[0189] (Comparative Example 2)

[0190] As Comparative Example 2, a joining test of an object 60 to be joined based on the joining method of dissimilar metal members disclosed in Patent Document 1 was performed.

[0191] Specifically, using the friction stirring spot welding device 50 involved in the present embodiment 1, in the process of step S103, a program is set to drive the pin driver 531 to press the pin member 11 into the joined portion. At this time, the program is set so that the tip of the pin member 11 is located at the first position 0.1 mm below the contact surface (upper surface) of the second member 62 that contacts the first member 61.

[0192] In addition, similar to Test Example 5, when the tip of the pin member 11 reaches the first position in step S105, the pin member 11 and the shoulder member 12 are pulled upward to stop the joining test.

[0193] (Joining condition 10)

[0194] A 1 mm aluminum plate (A6061) was used as the first member 61, and a 1.2 mm 270 MPa grade hot-dip galvanized steel plate (GI) was used as the second member 62. The first rotation speed of the pin member 11 and the shoulder member 12 was set to 1000 rpm.

[0195] (Test result 5)

[0196] Fig.11 This is a cross-sectional photograph of the workpieces that were subjected to friction stir spot welding under the welding condition 10 using the friction stir spot welding apparatus of Comparative Example 2 and Test Example 5. Fig.11 In the figure, the pin member is schematically shown by a dotted line, and the shoulder member is schematically shown by a single-dot chain line.

[0197] like Fig.11 As shown, when the friction stir spot welding of the workpiece 60 is performed by the friction stir spot welding apparatus of Comparative Example 2, the softened portion of the plastic flow portion 60a is pushed away by the pin member 11 and flows from just below the pin member 11 to just below the shoulder member 12. At this time, impurities (such as zinc, etc.) formed in the plating layer (plating film) formed on the surface of the second member 62 also flow to just below the shoulder member 12.

[0198] also, Fig.11 It is inferred that the portion directly below the right shoulder member 12 in the first portion 61 adheres (condenses) to the shoulder member 12 and breaks.

[0199] On the other hand, when the object 60 is friction stir spot welded using the friction stir spot welding apparatus of Test Example 5, the softened portion of the plastic flow portion 60a is pushed away by the shoulder component 12 and flows from directly below the shoulder component 12 to directly below the pin component 11.

[0200] At this time, most of the impurities (such as zinc) formed in the plating layer (plating film) formed on the surface of the second member 62 flow directly below the pin member 11. In addition, part of the impurities flow outward from the outer peripheral surface of the distal end of the shoulder member 12.

[0201] Therefore, the following insight is obtained: when the softened portion of the plastic flow portion 60a flows from directly below the pin member 11 to directly below the shoulder member 12 (a recess created by pressing the shoulder member 12), the amount of impurities flowing directly below the shoulder member 12 is reduced by an amount corresponding to the impurities flowing out.

[0202] In addition, if the results of the above-mentioned test example 4 (test result 4) are taken into consideration, it is inferred that the impurities flowing to the bottom of the pin part 11 remain (retain) directly below the pin part 11 when flowing from the bottom of the pin part 11 to the bottom of the shoulder part 12 in the softened part of the plastic flow portion 60a.

[0203] For those skilled in the art, it is possible to clarify more improvements or other embodiments of the present invention according to the above description. Therefore, the above description should be interpreted as only illustrative, and is provided for the purpose of teaching the best mode of performing the present invention to those skilled in the art. The details of its structure and / or function can be substantially changed without departing from the present invention. In addition, various inventions can be formed by the appropriate combination of a plurality of constituent elements disclosed in the above embodiment.

[0204] Industrial Applicability

[0205] Compared with the conventional method for joining dissimilar metal parts, the friction stir spot joining device and the operating method thereof of the present invention can shorten the joining time and are therefore useful.

[0206] Description of Reference Numerals

[0207] 11...pin component; 11a...end face; 12...shoulder component; 12a...end face; 13...clamping component; 13a...end face; 31...memory; 32...input device; 33...position detector; 41...clamping driver; 50...friction stir point joining device; 51...controller; 52...tool holder; 53...advance and retraction driver; 55...pad support portion; 56...pad component; 56a...support surface; 57...rotation driver; 60a...plastic flow portion; 60...object to be joined; 60c...surface; 61...first component; 62...second component; 62a...abutment surface; 521...rotation tool holder; 522...clamping holder; 531...pin driver; 532...shoulder driver; t...thickness; Xr...axis.

Claims

1. A friction stir spot welding device for joining a first component and a second component by softening the components to be joined by friction heat, It is characterized in that The friction stir spot welding device comprises: a pin member formed into a cylindrical shape; a shoulder member formed in a cylindrical shape and having the pin member inserted therein; A rotary driver that rotates the pin member and the shoulder member about an axis that coincides with the axis of the pin member; An advance and retreat driver, which enables the pin member and the shoulder member to move forward and backward along the axis respectively; as well as Controller, The first member is arranged to face the pin member and the shoulder member and is made of a material having a lower melting point than the second member. The controller is configured to execute: Action A, actuating the rotation driver and the advance / retract driver so that the pin member and the shoulder member press the engaged portion of the engaged object in a rotating state; Action B, operating the advance / retract actuator and the rotation actuator to make only the end of the shoulder member in the rotating state reach a predetermined first position in the second member, and to make the pin member in the rotating state retreat from the engaged portion of the engaged object; as well as Action C, after the action B, actuating the rotation driver and the advance / retract driver to extract the shoulder member in the rotation state from the engaged portion of the engaged object, and advancing the pin member in the rotation state toward the engaged portion of the engaged object, The object to be bonded is coated with a sealing material at a contact portion between the overlapped first component and the second component. The first position is located at a distance of 0.008 mm or more and 0.3 mm or less from a surface of the second member that faces the first member. The first component is an aluminum component, The second component is a steel component, The shoulder member is configured so that, when the radius of the distal end surface of the shoulder member is Rs and the radius of the distal end surface of the pin member is Rp, the following equation is satisfied: Rs>2 1 / 2 ×Rp, The pin member and the shoulder member rotate at the same speed.

2. A method for operating a friction stir spot welding device, wherein a first component and a second component are joined by softening the objects to be joined by friction heat, It is characterized in that The friction stir spot welding device comprises: a pin member formed into a cylindrical shape; a shoulder member formed in a cylindrical shape and having the pin member inserted therein; A rotary driver that rotates the pin member and the shoulder member about an axis that coincides with the axis of the pin member; An advance and retreat driver, which enables the pin member and the shoulder member to move forward and backward along the axis respectively; as well as Controller, The first member is arranged to face the pin member and the shoulder member and is made of a material having a lower melting point than the second member. The controller is configured to execute: Action A, actuating the rotation driver and the advance / retract driver so that the pin member and the shoulder member press the engaged portion of the engaged object in a rotating state; Action B, operating the advance / retract actuator and the rotation actuator to make only the end of the shoulder member in the rotating state reach a predetermined first position in the second member, and to make the pin member in the rotating state retreat from the engaged portion of the engaged object; as well as Action C, after the action B, actuating the rotation driver and the advance / retract driver to extract the shoulder member in the rotation state from the engaged portion of the engaged object, and advancing the pin member in the rotation state toward the engaged portion of the engaged object, The object to be bonded is coated with a sealing material at a contact portion between the overlapped first component and the second component. The first position is located at a distance of 0.008 mm or more and 0.3 mm or less from a surface of the second member that faces the first member. The first component is an aluminum component, The second component is a steel component, The shoulder member is configured so that, when the radius of the distal end surface of the shoulder member is Rs and the radius of the distal end surface of the pin member is Rp, the following equation is satisfied: Rs>2 1 / 2 ×Rp, The pin member and the shoulder member rotate at the same speed.

Images