Dissimilar material joining member and pressing tool of dissimilar material joining device used for said dissimilar material joining member

Abstract

To provide a dissimilar material connection member capable of reducing an installation cost and an installation space required for connecting dissimilar materials and mounting a stud, and a pressing tool for a dissimilar material connection device used in the dissimilar material connection member.SOLUTION: A dissimilar material connection member 10 connects a first member 50 and a second member 52 made of a material different from that of the first member 50. The dissimilar material connection member 10 comprises: a rivet part 12 that has a trunk part 20 press-fitted into the first member 50, and a first head part 22 provided at one end part of the trunk part 20 and having a larger diameter than the trunk part; and a stud part 14 that has a shaft part 26 protruding from the central part of the upper surface of the first head part 22, and a second head part 28 provided at the tip part of the shaft part 26 and having a diameter larger than that of the shaft part 26 and smaller than that of the first head part 22.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a dissimilar material joining member used for joining dissimilar materials, and a pressing tool of a dissimilar material joining apparatus used for the dissimilar material joining member. [Background technology]

[0002] In vehicles such as automobiles, a technology is adopted in which parts of the body are formed using aluminum panels in order to reduce the weight of the body. For example, Patent Document 1 describes a body structure in which a highly rigid steel panel is used for the body frame and a lightweight aluminum panel is used for the roof panel of the body that is joined to the steel panel.

[0003] When joining dissimilar metal components, spot welding, which involves melting and joining the metals, is not practical because of differences in melting points, linear expansion coefficients, etc. Therefore, mechanical joining using joining members such as rivets is used to join dissimilar materials.

[0004] A roof molding, which is an exterior component, is attached to the joining surface between the body frame and the roof panel. As described in Patent Document 2, this roof molding is assembled by being engaged with a stud with a T-shaped cross section that is erected on the joining surface between the body frame and the roof panel. After the body frame and the roof panel are joined with a joining member, the stud is attached to the joining surface by welding. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-119577 [Patent Document 2] Japanese Patent Application Laid-Open No. 2005-219534 Summary of the Invention [Problem to be solved by the invention]

[0006] As described above, when assembling a roof panel and a roof molding made of different materials to a vehicle body frame, a joining device for riveting the body frame and the roof panel and a welding device for welding studs for attaching the roof molding to the joining surfaces are required. As such, the need for two different devices during assembly has led to problems of increased equipment costs and a large amount of equipment space.

[0007] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a dissimilar material joining member that can reduce the equipment costs and equipment space required for joining dissimilar materials and attaching studs, and a pressing tool for a dissimilar material joining device used with the dissimilar material joining member. [Means for solving the problem]

[0008] In order to achieve the above object, one embodiment of the present invention comprises: Made of metal materials A first member and a second member different from the first member metal A dissimilar material joining member that joins a first member made of a material to a second member made of a material, laminated to the second member The first member has a body portion that is press-fitted into the first member, and a first head portion that is provided at one end of the body portion and has a larger diameter than the body portion. The body portion is plastically deformed to crimp and join the first and second members. a rivet portion projecting from the center of the upper surface of the first head portion; a shaft portion projecting from the top center of the first head portion; and a second head portion provided at the tip of the shaft portion and formed to have a diameter larger than that of the shaft portion and smaller than that of the first head portion. Then, a third member is attached. a stud portion; The second head is formed in a substantially V-shape that widens in the radial direction as it moves away from the shaft portion, and has an inclined surface at its tip that is inclined with respect to the axial direction of the shaft portion and to which a pressing force is applied when joining the first and second members. It is characterized by:

[0009] Moreover, one embodiment of the present invention is A pressing tool of the dissimilar material joining apparatus is applied to the dissimilar material joining member, and when the rivet portion is set at the joining position of the first member, the pressing tool abuts against a first head of the rivet portion to apply a pressing force to the first head toward the body portion. The pressing tool has a recess in which the stud portion is housed, and the recess of the pressing tool has, on a part of an inner wall surface, an abutment surface that abuts against the inclined surface of the dissimilar material joining member. It is characterized by:

[0011] Moreover, one embodiment of the present invention is A dissimilar material joining member for joining a first member made of a metallic material and a second member made of a metallic material different from the first member, the dissimilar material joining member having: a body portion that is press-fitted into the first member that is layered on the second member; and a first head portion that is provided at one end of the body portion, has a diameter larger than the body portion, and has a recessed groove into which the first member fits, the first head portion fitting into the first member, and the body portion passing through the first member, and is welded to the second member, the first and second members being joined by fit welding. a stud portion to which a third member is attached, the stud portion having a first end, a shaft portion protruding from the center of the upper surface of the first head, and a second head portion provided at the tip of the shaft portion and formed with a diameter larger than that of the shaft portion and smaller than that of the first head, the stud portion having a third member attached thereto, wherein the barrel portion of the rivet portion is a solid cylinder with a smooth peripheral surface and has a tapered tip portion, and the tip portion is welded to the second member by frictional heat generated between the barrel portion and the second member as they are rotated about their axis when joining the first and second members.A pressing tool of a dissimilar material joining device is applied to a dissimilar material joining member, and when the rivet portion is set in the joining position of the first member, the pressing tool abuts against the first head of the rivet portion to apply a pressing force to the first head toward the body portion. The pressing tool has a recess that accommodates the stud portion and an engagement groove that engages with the first head, and when engaged with the first head, applies the pressing force and also applies a rotational force around the axis to the body portion of the dissimilar material joining member. [Effects of the Invention]

[0013] The dissimilar material joining member and the pressing tool of the dissimilar material joining apparatus according to the present invention can reduce the equipment costs and equipment space required for joining dissimilar materials and attaching studs. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a cross-sectional view showing a dissimilar material bonding member and a dissimilar material bonding apparatus according to a first embodiment of the present invention. [Figure 2A] FIG. 2 is a side view of a dissimilar material bonding member. [Figure 2B] FIG. 2 is a plan view of a dissimilar material bonding member. [Figure 3A] 5A to 5C are cross-sectional views showing a procedure for joining a first member and a second member. [Figure 3B] 5A to 5C are cross-sectional views showing a procedure for joining a first member and a second member. [Figure 3C] 5A to 5C are cross-sectional views showing a procedure for joining a first member and a second member. [Figure 3D] 5A to 5C are cross-sectional views showing a procedure for joining a first member and a second member. [Figure 4] FIG. 4 is a cross-sectional view showing a second embodiment of a dissimilar material bonding member and a dissimilar material bonding device. [Figure 5] FIG. 10 is a perspective view showing a third embodiment of a dissimilar material bonding member. [Figure 6A] 10A to 10C are cross-sectional views showing a procedure for joining a first member and a second member using a dissimilar material joining member and an apparatus for joining dissimilar materials according to the third embodiment. [Figure 6B] 10A to 10C are cross-sectional views showing a procedure for joining a first member and a second member using a dissimilar material joining member and an apparatus for joining dissimilar materials according to the third embodiment. [Figure 7] FIG. 10 is a perspective view showing a fourth embodiment of a dissimilar material bonding member. [Figure 8A] 10A to 10C are cross-sectional views showing a procedure for joining a first member and a second member using a dissimilar material joining member and an apparatus for joining dissimilar materials according to a fourth embodiment. [Figure 8B] 10A to 10C are cross-sectional views showing a procedure for joining a first member and a second member using a dissimilar material joining member and an apparatus for joining dissimilar materials according to a fourth embodiment. [Figure 9A] 10A to 10C are cross-sectional views showing a procedure for joining a first member and a second member using a dissimilar material joining member and an apparatus for joining dissimilar materials according to the fifth embodiment. [Figure 9B] 10A to 10C are cross-sectional views showing a procedure for joining a first member and a second member using a dissimilar material joining member and an apparatus for joining dissimilar materials according to the fifth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0015] (First embodiment) Fig. 1 is a cross-sectional view showing a dissimilar material joining device 30 equipped with a dissimilar material joining member 10 and a pressing tool according to a first embodiment of the present invention, Fig. 2 is a side view of the dissimilar material joining member 10, and Fig. 3 is a plan view of the dissimilar material joining member 10. The dissimilar material joining member 10 is a member used when joining multiple members made of different materials.

[0016] In this embodiment, an example is shown in which a dissimilar material joining member 10 is used to join two metal members made of different materials, specifically, a first member 50 made of aluminum or an aluminum alloy and a second member 52 made of steel that is more rigid than the first member 50. The first member 50 and the second member 52 are plate-shaped at the joining portion, and are joined by the dissimilar material joining member 10 with the first member 50 stacked on the second member 52.

[0017] The dissimilar material joining member 10 includes a rivet portion 12 used for joining dissimilar materials and a stud portion 14 formed integrally with the rivet portion 12. The rivet portion 12 has a body portion 20 that is press-fit into a first member 50, and a first head portion 22 that is provided at one end of the body portion 20 and has a larger diameter than the body portion 20. The stud portion 14 has a shank portion 26 that protrudes from the center of an upper surface 22a of the first head portion 22, and a second head portion 28 that is provided at the tip of the shank portion 26. In the following description, the first head portion 22 will also be referred to as the rivet head portion 22, and the second head portion 28 will also be referred to as the stud head portion 28.

[0018] In this embodiment, the rivet portion 12 constitutes a so-called self-piercing rivet that joins the first member 50 and the second member 52 by crimping. As shown in Figures 2A and 2B, the body portion 20 of the rivet portion 12 is formed in a substantially cylindrical shape, and the tip portion 20a, which is distal from the rivet head 22, is formed to be tapered. The rivet head 22 is formed in a substantially disk shape, and the top surface 22a, to which the stud portion 14 is attached, is formed to be flat. The diameter of the rivet head 22 is larger than the outer diameter of the body portion 22. The axial length of the body portion 20 is formed to be larger than the plate thickness of the first member 50.

[0019] In this embodiment, the stud portion 14 constitutes a T-stud with a T-shaped cross section, as shown in Figure 1. The shank 26 of the stud portion 14 extends from the rivet head 22 coaxially with the barrel portion 20 and is formed in a solid cylindrical shape. The outer diameter of the shank 26 is smaller than the outer diameter of the barrel portion 20. The stud head 28 is formed in a disk shape coaxial with the shank 26 and has an outer diameter larger than that of the shank 26 but smaller than that of the rivet head 22. The rivet portion 12 and the stud portion 14 are formed of the same material, and can be formed of a metal material such as steel or an aluminum alloy, for example.

[0020] Next, a dissimilar material joining device 30 used in the dissimilar material joining component 10 will be described. The above-described dissimilar material joining component 10 can be made by simply changing the shape of the punch (pressing tool) that applies a pressing force to the rivet in a dissimilar material joining device used for an existing dissimilar material joining rivet that does not have a stud portion 14. As shown in FIG. 1 , the dissimilar material joining device 30 includes a die 31 that supports the back surface 52 a of the second component 52, a holding portion 32 that presses the first and second components 50, 52 against the die 31, and a punch 34 that strikes the dissimilar material joining component 10 against the first component 50 and the second component 52. The punch 34 constitutes a pressing tool that abuts against the rivet head 22 of the dissimilar material joining component 10 and applies a pressing force to the rivet head 22 toward the body portion 20.

[0021] The die 31 has a cavity 31b formed in a concave shape on a top surface 31a facing the punch 34. The cavity 31b has a circular recessed shape in a plan view, and has a protruding portion in the center where the inner wall surface is convex.

[0022] The holding portion 32 is formed in a cylindrical shape extending in the vertical direction and is arranged coaxially with the cavity 31b. The punch 34 is formed in a cylindrical shape and is configured to be movable axially within the holding portion 32 by a drive device (not shown). The outer diameter of the punch 34 is set to be approximately the same as the outer diameter of the rivet head 22. A recess 36 is formed in the tip surface 34a of the punch 34, i.e., the surface that abuts against the dissimilar material joining component 10, to accommodate the stud portion 14 of the dissimilar material joining component 10. The recess 36 is formed to a size that can accommodate the entire stud portion 14, and in this embodiment, the tip surface 34a of the punch 34 is formed with a cylindrical recess 36.

[0023] Next, a procedure for joining the first member 50 and the second member 52, which are members to be joined, using the dissimilar material joining member 10 and the dissimilar material joining apparatus 30 described above will be described.

[0024] First, as shown in FIG. 1 , the second member 52 and the first member 50 are placed on top of each other in this order on the die 31, and the presser 32 is brought into contact with the surface 50a of the first member 50 to press the members to be joined against the die 31. The dissimilar material joining member 10 is held inside the presser 32 and below the punch 34. At this time, the stud portion 14 of the dissimilar material joining member 10 is housed in the recess 36 of the punch 34. Thereafter, as shown in FIG. 3A , the punch 34 receives a pushing force from the drive unit and moves downward within the presser 32 so as to approach the die 31, whereby the dissimilar material joining member 10 is driven into the members to be joined.

[0025] 3B and 3C, the hollow body 20 of the dissimilar material joining member 10 penetrates the first member 50. As the penetration of the body 20 progresses, the second member 52, which is pushed by the body 20 and the first member 50, undergoes plastic deformation toward the bottom surface of the cavity 31b. After a portion of the second member 52 reaches the bottom surface of the cavity 31b, it plastically deforms into a shape that conforms to the inner wall surface of the cavity 31b, and the tip of the body 20 bites into the second member 52 while undergoing radially expanding deformation. As a result, the first member 50 and the second member 52 are crimped and joined by the rivet portion 12 of the dissimilar material joining member 10, as shown in FIG. 3D. In the joined state, the rivet head 22 of the dissimilar material joining member 10 is substantially flush with the surface 50a of the first metal member 50, and the stud portion 14 protrudes from this surface 50a. This stud portion 14 can be used as a fastener for attaching another member to the joined body consisting of the first member 50 and the second member 52.

[0026] As described above, in the dissimilar material joining device 30 of this embodiment, the punch 34 is formed with the recess 36 that accommodates the stud portion 14, allowing the rivet portion 12 of the dissimilar material joining member 10 to join dissimilar materials without being affected by the stud portion 14. Furthermore, the dissimilar material joining member 10 of this embodiment can join dissimilar materials while simultaneously attaching the stud portion 14, which functions as a fastener for attaching other components to the joined structure. As a result, for example, during the vehicle body assembly process, by using the dissimilar material joining member 10 to join an aluminum alloy roof panel to a steel vehicle body frame, the work of welding studs to attach a roof molding to the joined portion can be eliminated. In this way, the dissimilar material joining member 10 and dissimilar material joining device 30 of this embodiment can simultaneously join dissimilar materials and attach the stud portion 14 using a single device, thereby reducing equipment costs and space required during the vehicle body assembly process.

[0027] 3A to 3C, in the dissimilar material joining device 30, there is a gap between the stud portion 14 of the dissimilar material joining component 10 and the inner wall surface of the recess 36 of the punch 34, but the configuration may also be such that when the dissimilar material joining component 10 is set with the stud portion 14 housed in the recess 36, the inner wall surface of the recess 36 abuts against the upper surface of the stud head 28. In such a case, when the punch 34 presses the rivet head 22 of the dissimilar material joining component 10, the inner wall surface of the recess 36 presses the stud head 28 of the dissimilar material joining component 10 toward the rivet portion 12, making it possible to drive the dissimilar material joining component 10 into the workpieces with greater force.

[0028] Next, we will explain other embodiments of the dissimilar material joining member 10 and the dissimilar material joining device 30. In the second to fifth embodiments explained below, elements similar to those in the first embodiment described above are given the same reference numerals, and their explanation will be omitted.

[0029] (Second embodiment) 4 is a cross-sectional view similar to FIG. 3A showing a second embodiment of the dissimilar material joining member 10 and the dissimilar material joining device 30. In the second embodiment, the shape of the stud head 28 of the dissimilar material joining member 10 differs from that of the first embodiment, and the shape of the recess 36 of the dissimilar material joining device 30 differs from that of the first embodiment. The other configurations are the same as those of the first embodiment.

[0030] The stud head 28 of this embodiment has a circular outer diameter in plan view, and a longitudinal cross section passing through the central axis is formed into a generally V-shape that widens radially as it moves away from the shank 26, as shown in Figure 4. The stud head 28 has an inclined surface 29 at its tip that is inclined relative to the axial direction of the shank 26.

[0031] The punch 34 of the dissimilar material joining device 30 has a contact surface 39 on part of the inner wall surface of the recess 36 that houses the stud portion 14, which contacts the inclined surface 29 of the stud head 28. The contact surface 39 is an inclined surface that contacts and faces the inclined surface 29, and is formed around the entire periphery of the columnar recess 36.

[0032] In the dissimilar material joining member 10 and dissimilar material joining device 30 of this embodiment, when the punch 34 drives the dissimilar material joining member 10, the abutment surface 39 abuts against and presses the inclined surface 29 of the stud head 28, applying force in the direction of pressing the body 20 of the rivet portion 12 into the joined members, as shown by the arrow in Figure 4. This improves the press-fitting accuracy of the rivet portion 12.

[0033] (Third embodiment) Next, a description will be given of a third embodiment of the dissimilar material joining member 10 and the dissimilar material joining apparatus 30. Fig. 5 is a perspective view showing the third embodiment of the dissimilar material joining member 10, and Figs. 6A and 6B are cross-sectional views similar to Figs. 3A and 3C showing a procedure for joining a first member 50 and a second member 52 using the dissimilar material joining member 10 and the dissimilar material joining apparatus 30 of the third embodiment.

[0034] The dissimilar material joining member 10 of this embodiment joins a first member 50 and a second member 52 by screwing together the rivet portion 12. The rivet portion 12 has a solid, approximately cylindrical body portion 60 and a rivet head portion 62, which is a first head, provided at one end of the body portion 60. The body portion 60 has a thread 61 formed on its outer circumferential surface, and the tip portion has a tapered, pointed shape. The rivet head 62 is formed with a larger diameter than the body portion 60, and an engagement portion 64 protrudes from an upper surface 62a of the disk-shaped main body for engaging with the push-in portion 44, which is a pressing tool of the dissimilar material joining device 30. A recessed groove 62b is formed on the back surface of the rivet head 62, recessed toward the upper surface 62a along the outer periphery of the body portion 60. The rivet portion 12 of this embodiment constitutes a so-called flow drilling screw, which is rotated and pressed into the first member 50 and the second member 52.

[0035] The stud portion 14 of the dissimilar material joining member 10 has a shank portion 66 that protrudes from the center of the rivet head 62, and a stud head portion 68 that is a second head portion provided at the tip of the shank portion 66. The stud head portion 68 is formed with a diameter larger than that of the shank portion 66 and smaller than that of the rivet head 62. The stud portion 14 of this embodiment forms a T-stud with a T-shaped cross section, similar to the first embodiment.

[0036] 6A, the dissimilar material joining device 30 includes a cylindrical support portion 42 and a columnar push-in portion 44 that is configured to be movable up and down in the axial direction and rotatable around its axis within the support portion 42. An engagement groove 44a that engages with the engagement portion 64 of the dissimilar material joining member 10 is formed circumferentially on the tip surface of the push-in portion 44. The push-in portion 44 also has a recess 46 in the center of the tip surface that receives the stud portion 14 of the dissimilar material joining member 10.

[0037] 6A , in the dissimilar material joining member 10 and dissimilar material joining device 30 of this embodiment, when the dissimilar material joining member 10 is set at a joining position for the first member 50 and the second member 52 and the engaging portion 64 of the dissimilar material joining member 10 is engaged with the engaging groove 44a of the pushing-in portion 44, the stud portion 14 is accommodated in the recess 46 of the pushing-in portion 44. In this state, when the pushing-in portion 44 is pushed toward the members to be joined while rotating at high speed, the dissimilar material joining member 10 rotates together with the pushing-in portion 44, and frictional heat generated by the rotation softens the first member 50 and the second member 52, causing the body portion 60 of the dissimilar material joining member 10 to penetrate the first member 50 and the second member 52. As shown in Figure 6B, when the joining is complete, the plastic flow of the first member 50 and the second member 52 causes a thread to be formed by the joined members around the thread 61, and the material of the first member 50 enters the groove 62b of the rivet head 62.

[0038] (Fourth embodiment) Next, a description will be given of a fourth embodiment of the dissimilar material joining member 10 and the dissimilar material joining apparatus 30. Fig. 7 is a perspective view showing the fourth embodiment of the dissimilar material joining member 10, and Figs. 8A and 8B are cross-sectional views similar to Figs. 3A and 3C showing a procedure for joining a first member 50 and a second member 52 using the dissimilar material joining member 10 and the dissimilar material joining apparatus 30 of the fourth embodiment.

[0039] The dissimilar material joining member 10 of this embodiment joins a first member 50 and a second member 52 by fit welding using a rivet portion 12. The rivet portion 12 is formed from an iron material and has a solid, approximately cylindrical body portion 70 and a rivet head portion 72, which is a first head, provided at one end of the body portion 70. The tip of the body portion 70 has a tapered, pointed shape. The rivet head 72 has a larger diameter than the body portion 70, and an engagement portion 74 protrudes from the upper surface 72a of the disk-shaped main body for engaging with the push-in portion 44, which is a pressing tool of the dissimilar material joining device 30. A recessed groove 72b is formed on the back surface of the rivet head 72, recessed toward the upper surface 62a along the outer periphery of the body portion 70.

[0040] The stud portion 14 is formed integrally with the rivet portion 12 and, like the first embodiment, constitutes a T-stud with a T-shaped cross section. The stud portion 14 has a shank 76 that protrudes from the center of the rivet head 72, and a stud head 78, which is a second head, provided at the tip of the shank 76. The stud head 78 is formed with a diameter larger than the shank 76 but smaller than the rivet head 72.

[0041] 8A, the dissimilar material joining device 30 includes a cylindrical support portion 42 and a columnar push-in portion 44 that is configured to be movable up and down in the axial direction and rotatable around the axis inside the support portion 42. An engagement groove 44a that engages with the engagement portion 74 of the dissimilar material joining member 10 is formed circumferentially on the tip surface of the push-in portion 44, and a recess 46 that accommodates the stud portion 14 is formed in the center of the tip surface.

[0042] In the dissimilar material joining member 10 and dissimilar material joining device 30 of this embodiment, as shown in Fig. 8A, when the dissimilar material joining member 10 is set at a joining position for the first member 50 and the second member 52 and the engagement portion 74 of the dissimilar material joining member 10 is engaged with the engagement groove 44a of the push-in portion 44, the stud portion 14 is accommodated in the recess 46 of the push-in portion 44. In this state, when the push-in portion 44 is rotated at high speed and pushed toward the members to be joined, frictional heat caused by the rotation causes the body portion 70 of the dissimilar material joining member 10 to penetrate the first member 50, and the tip end of the body portion 70 is friction stir welded to the second member 52, as shown in Fig. 8B. Furthermore, the material of the first member 50 flows into the recess 72b of the rivet head 72 due to plastic flow, creating a fitted state.

[0043] (Fifth embodiment) Next, a description will be given of a fifth embodiment of the dissimilar material joining member 10 and the dissimilar material joining apparatus 30. Figures 9A and 9B are cross-sectional views showing a procedure for joining a first member 50 and a second member 52 using the dissimilar material joining member 10 and the dissimilar material joining apparatus 30 of the fifth embodiment.

[0044] The dissimilar material joining member 10 of this embodiment joins a first member 50 and a second member 52 by fit welding with a rivet portion 12. The rivet portion 12 is formed from an iron material and has a solid, approximately cylindrical body portion 80 and a rivet head 82, which is a first head, provided at one end of the body portion 80. The tip of the body portion 80 has a tapered, pointed shape. The rivet head 82 is formed in a disk shape with a larger diameter than the body portion 80. A recessed groove 82b is formed on the back surface of the rivet head 82, recessed toward an upper surface 82a along the outer periphery of the body portion 80.

[0045] The stud portion 14 is formed integrally with the rivet portion 12 and, like the first embodiment, constitutes a T-stud with a T-shaped cross section. The stud portion 14 has a shank 86 that protrudes from the center of the rivet head 82, and a stud head 88 that is a second head provided at the tip of the shank 86. The stud head 88 is formed with a diameter larger than the shank 86 but smaller than the rivet head 82.

[0046] As shown in FIG. 9A , the dissimilar material joining device 30 includes a first electrode 90 and a second electrode 92 disposed opposite the first electrode 90. Either the first electrode 90 or the second electrode 92 is configured to be able to move toward or away from the other electrode. The second electrode 92 constitutes a pressing tool that applies a pressing force to the dissimilar material joining component 10 when joining the first and second components 50, 52. The outer diameter of the second electrode 92 is larger than the outer diameter of the stud head 28. The tip of the second electrode 92 is formed flat so as to abut against the flat upper surface 82a of the rivet head 82 of the dissimilar material joining component 10, and a cylindrical recess 94 capable of accommodating the stud portion 14 of the dissimilar material joining component 10 is formed in its center.

[0047] In the dissimilar material bonding member 10 of this embodiment, the dissimilar material bonding member 10 is driven into a first metal 50, and the rivet portion 12 of the first member 50 and the dissimilar material bonding member 10 is crimped. Then, as shown in Fig. 9A, the second member 52 and the dissimilar material bonding member 10 are sandwiched between first and second electrodes 90, 92, and electricity is passed between the electrodes while applying a pressing force. This welds the rivet portion 12 of the dissimilar material bonding member 10 and the second member 52, and as shown in Fig. 9B, a nugget 54 is formed at their joining surfaces. This bonds the first member 50 and the second member 52.

[0048] As described above, in the dissimilar material joining member 10 and dissimilar material joining device 30 of the third to fifth embodiments, the depressions 46, 96 for accommodating the stud portion 14 are formed in the pressing tool, i.e., the pressing portion 44 and the second electrode 92. Therefore, the first member 50 and the second member 52 made of dissimilar materials can be joined by the rivet portion 12 of the dissimilar material joining member 10 without being affected by the stud portion 14. Furthermore, the stud portion 14, which functions as a fastener for attaching another member to this joined body, can be attached simultaneously with joining the dissimilar materials. Note that in the third to fifth embodiments, a pressing tool having an abutment surface 39 can also be applied to the stud head portion 28 and depression 36 of the dissimilar material joining member 10 having the inclined surface 29 described in the second embodiment.

[0049] The present invention is not limited to the above-described embodiment and modifications, and various modifications are possible without departing from the spirit of the invention. [Explanation of symbols]

[0050] 10. Dissimilar material bonding components 12 Rivet section 14 Stud section 20,60,70,80 Torso 22, 62, 72, 82 Rivet head (first head) 26,66,76,86 Shaft 28, 68, 78, 88 stud head (second head) 29 Slope 30 Dissimilar material joining device 31 Die 32 Presser foot 34 Punch (pressure tool) 36 Recess 39 Contact surface 42 Support part 44 Pressing part (pressing tool) 46 Recess 50 First member 52 Second member 90 First electrode 92 Second electrode (pressure tool) 96 Recess

Claims

1. A dissimilar material joining member that joins a first member made of a metal material and a second member made of a metal material different from the first member, a rivet portion having a body portion press-fitted into the first member laminated on the second member, and a first head portion provided at one end of the body portion and formed with a diameter larger than that of the body portion, the body portion plastically deforming to crimp and join the first and second members; a stud portion to which a third member is attached, the stud portion having a shaft portion protruding from a central portion of an upper surface of the first head portion and a second head portion provided at a tip end of the shaft portion and formed with a diameter larger than that of the shaft portion and smaller than that of the first head portion; Equipped with The second head is formed in an approximately V-shape that expands radially as it moves away from the shaft portion, and has an inclined surface at its tip that is inclined with respect to the axial direction of the shaft portion and to which a pressing force is applied when joining the first and second members.

2. The dissimilar material bonded member according to claim 1, a pressing tool of an apparatus for joining dissimilar materials, the pressing tool being configured to abut against a first head of the rivet portion and apply a pressing force to the first head toward the body portion while the rivet portion is set at a joining position of the first member; the pressing tool has a recess in which the stud portion is received, The pressing tool of the dissimilar material joining apparatus, wherein the recess of the pressing tool has, on a part of an inner wall surface, an abutment surface that abuts against the inclined surface of the dissimilar material joining member.

3. A dissimilar material joining member that joins a first member made of a metal material and a second member made of a metal material different from the first member, a rivet portion having a body portion press-fitted into the first member laminated on the second member, and a first head portion provided at one end of the body portion, formed with a diameter larger than the body portion and having a recessed groove into which the first member fits, the rivet portion joining the first and second members by fit welding in which the first head fits into the first member and the body portion penetrates the first member and is welded to the second member; a stud portion to which a third member is attached, the stud portion having a shaft portion protruding from a central portion of an upper surface of the first head portion and a second head portion provided at a tip end of the shaft portion and formed with a diameter larger than that of the shaft portion and smaller than that of the first head portion; Equipped with The body of the rivet part is a solid cylindrical part having a smooth peripheral surface and a tapered tip, The tip portion is applied to a dissimilar material joining member, characterized in that, when joining the first and second members, the tip portion is welded to the second member by frictional heat generated between the body portion rotated about an axis and the second member, a pressing tool of an apparatus for joining dissimilar materials, the pressing tool being configured to abut against a first head of the rivet portion and apply a pressing force to the first head toward the body portion while the rivet portion is set at a joining position of the first member; The pressing tool of the dissimilar material joining device has a recess in which the stud portion is accommodated and an engagement groove that engages with the first head, and when engaged with the first head, applies the pressing force and also applies a rotational force about an axis to the body portion of the dissimilar material joining member.

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