Abstract:
A dissimilar material joining member includes (1) a metal tubular portion having (i) a flange and (ii) a deformable portion that deforms upon being clinched, and (2) a metal cylindrical member. The tubular portion passes through a first resin member that is to be joined to a second metal member. The flange extends radially outward from a first axial end of the tubular portion. The deformable portion is provided at a second axial end of the tubular portion. The deformable portion holds the first resin member between the deformable portion and the flange once the deformable potion is deformed so as to expand radially outward. The metal cylindrical member is attached to and within the tubular portion at the first axial end of the tubular portion and can be spot-welded to the second metal member to thereby join the first resin member to the second metal member.

Description:
INCORPORATION BY REFERENCE 
       [0001]    The disclosure of Japanese Patent Application No. 2015-120137 filed on Jun. 15, 2015 including the specification, drawings and abstract is incorporated herein by reference in its entirety. 
       BACKGROUND 
       [0002]    1. Technical Field 
         [0003]    The disclosure relates to a dissimilar material joining member, a dissimilar material joined structure, and a method for manufacturing a dissimilar material joined body. 
         [0004]    2. Description of Related Art 
         [0005]    A technique for joining dissimilar materials together has been known (see Japanese Patent Application Publication Nos. 2013-22622 and 2011-189698). For example, JP 2013-22622 A discloses joining a steel member and an aluminum alloy member by using a piercing metal made of steel. Briefly, in the publication, the piercing metal made of steel that passes through the aluminum alloy member is clinched, and the piercing metal made of steel and the steel member are joined together by spot welding. Here, in a head portion of the piercing metal made of steel, a groove is formed in a surface superimposed on the aluminum alloy member so as to surround a shaft portion, and a portion of the aluminum alloy member pressed during the clinching flows into the groove. 
       SUMMARY 
       [0006]    There is a need to join a metal member and a resin member. For example, when a resin member is applied instead of the aluminum alloy member described in JP 2013-22622 A described above, there occurs a problem such as cracking and creep of the resin member in association with a clinching operation. 
         [0007]    In consideration of the above circumstances, an object of embodiments is to obtain a dissimilar material joining member, a dissimilar material joined structure, and a method for manufacturing a dissimilar material joined body, in which a first member made of metal and a second member made of resin can be suitably joined together. 
         [0008]    In a first aspect, a dissimilar material joining member includes a tubular portion made of metal and having (i) a flange and (ii) a deformable portion to be clinched thereby defining a first joining component made of metal, and a second joining component that is defined by a metal cylindrical member. The tubular portion can be passed through a first resin member. The flange extends radially outward from a first axial end of the tubular portion. The deformable portion deforms upon being clinched and is provided at a second axial end of the tubular portion. The deformable portion holds the first resin member between the deformable portion and the flange once the deformable portion is deformed by application to the tubular portion of a compressive load having at least a predetermined value, the compressive load being applied to the tubular portion in an axial direction of the tubular portion such that a center portion in a direction along the axial direction of the tubular portion is expanded radially outward to form a fold-back portion. The metal cylindrical member has an axial length that is less than an axial length of the tubular portion, is fixed to the tubular portion inside the tubular portion at the first axial end of the tubular portion, and defines the second joining component that is configured to be spot-welded to a second metal member. 
         [0009]    In accordance with the above aspect, in the dissimilar material joining member, the metal cylindrical member is fixed to the tubular portion in a state in which the metal cylindrical member is coaxially inserted into the tubular portion. The tubular portion passes through the first resin member, the flange extends radially outward of the tubular portion, and the second axial end of the tubular portion is formed as the deformable portion to be clinched. The deformable portion holds the first resin member between the deformable portion and the flange by being bent such that the center portion in the direction along the axial direction of the tubular portion is expanded radially outward to form the fold-back portion when a compressive load with a predetermined value or more is inputted to the tubular portion in the axial direction. 
         [0010]    Therefore, it is possible to fix the first joining component to the first resin member while suppressing local load input to the first resin member. Also, since a distal-end opening portion of the deformable portion (that is, an opening end on the second axial end of the tubular portion) is not increased in diameter (or is almost not increased in diameter) when the deformable portion to be clinched is folded back and deformed as described above, a situation in which the distal-end opening portion of the deformable portion cracks during clinching can be avoided (or is highly likely to be avoided). Also, one end of the metal cylindrical member can be spot-welded to the second metal member. Accordingly, the second metal member is joined to the first resin member via the second joining component and the first joining component. 
         [0011]    In the above aspect, a proximal portion of the deformable portion may include a first tapered surface. The first tapered surface is inclined toward a radially inner side of the tubular portion as the first tapered surface extends toward the first axial end of the tubular portion, and extends around a peripheral of the deformable portion. A distal end portion of the deformable portion may include a second tapered surface. The second tapered surface is inclined toward the radially inner side of the tubular portion as the second tapered surface extends toward the second axial end of the tubular portion, and extends around the peripheral of the deformable portion. 
         [0012]    In accordance with the above aspect, when the compressive load with a predetermined value or more is inputted to the tubular portion in the axial direction, a load along an inclination direction of the first tapered surface is applied to the proximal portion of the deformable portion, and a load along an inclination direction of the second tapered surface is applied to the distal end portion of the deformable portion. The deformable portion is deformed by the loads applied as described above so as to be bent radially outward from the proximal portion, and be folded back at an intermediate portion between the proximal portion and the distal end portion of the deformable portion. Therefore, when the compressive load with a predetermined value or more is inputted to the tubular portion in the axial direction in a state in which the flange is brought into contact with the first resin member by passing the tubular portion through the first resin member, the deformable portion is deformed as described above, and the first resin member is held between the flange and the deformable portion. 
         [0013]    In the above aspect, the proximal portion may include a step surface. The step surface forms a V-shaped groove in section together with the first tapered surface, and is perpendicular to the axial direction of the tubular portion. 
         [0014]    In accordance with the above aspect, the step surface that is formed on the proximal portion of the deformable portion forms the V-shaped groove together with the first tapered surface, and is perpendicular to the axial direction of the tubular portion. Therefore, when the compressive load with a predetermined value or more is inputted to the tubular portion in the axial direction, the deformable portion can be stably bent along a direction perpendicular to the axial direction of the tubular portion from the proximal portion. Therefore, when the deformable portion is bent and deformed radially outward, the first resin member is stably held between the flange and the deformable portion. 
         [0015]    In a second aspect, a dissimilar material joined structure includes the dissimilar material joining member according to the first aspect, the first resin member, which has a first surface and an opposite, second surface, and the second metal member, which has first and second oppositely-facing surfaces. The tubular portion extends through an opening of the first resin member. The first surface of the first resin member contacts the flange of the tubular portion. The deformable portion has been expanded by application of the compressive load so as to contact the second surface of the first resin member such that the first resin member is sandwiched between the flange and the expanded deformable portion. One axial end of the metal cylindrical member is spot-welded to the second metal member. 
         [0016]    In accordance with the above aspect, in the first joining component, the tubular portion passes through the first resin member, and the flange extends radially outward from the first axial end of the tubular portion and the deformable portion, which has been clinched, is provided at the second axial end of the tubular portion so as to hold the first resin member. Therefore, it is possible to fix the first joining component to the first resin member while suppressing local load input to the first resin member. Also, the clinched deformable portion to hold the first resin member between the flange and the deformable portion. That is, in such a configuration, a distal-end opening portion of the clinched deformable portion (that is, an opening end composed of the fold-back end portion) has about the same diameter as that of the tubular portion. Thus, it is not necessary (or it is almost not necessary) to increase the diameter of the distal-end opening portion of the clinched deformable portion during clinching. Therefore, a situation in which the distal-end opening portion of the clinched deformable portion cracks during clinching can be avoided (or is highly likely to be avoided). 
         [0017]    Also, the metal cylindrical member is fixed to the tubular portion in a state in which it is coaxially inserted into the tubular portion. One of ends of the metal cylindrical member is spot-welded to the second metal member that is disposed facing the first resin member. That is, the second metal member is joined to the first resin member via the second joining component and the first joining component. 
         [0018]    A method of manufacturing a dissimilar material joined body using the dissimilar material joining member according to the first aspect includes a) to c) described below: 
         [0019]    a) bringing the flange of the tubular portion into contact with the first resin member by passing the tubular portion through the first resin member; 
         [0020]    b) after the flange is contacted with the first resin member, applying the compressive load to the deformable portion such that the center portion in the direction is expanded radially outward to form the fold-back portion, and holding the first resin member between the bent deformable portion and the flange; and 
         [0021]    c) after performing the holding, spot-welding one axial end of the metal cylindrical member to the second metal member. 
         [0022]    In accordance with the above aspect, when bringing the flange into contact with the first resin member, the flange is brought into contact with the first resin member by passing the tubular portion through the first resin member. In the holding after bringing the flange into contact with the first resin member, the deformable portion is bent such that the center portion in the direction along the axial direction of the tubular portion in the deformable portion is expanded radially outward to form the fold-back portion, and the first resin member is held between the bent deformable portion and the flange. Therefore, it is possible to fix the first joining component to the first resin member while suppressing local load input to the first resin member. Also, since the distal-end opening portion of the deformable portion is not increased in diameter (or is almost not increased in diameter) when the deformable portion to be clinched is folded back and deformed as described above, the situation in which the distal-end opening portion of the deformable portion cracks in the holding (that is, during clinching) can be avoided (or is highly likely to be avoided). In the spot-welding after the holding, the one axial end of the metal cylindrical member is spot-welded to the second metal member by disposing the second metal member facing the first resin member. Accordingly, the second metal member can be joined to the first resin member via the second joining component and the first joining component. 
         [0023]    As described above, the embodiments have an excellent effect that the second joining-object member made of metal and the first joining-object member made of resin can be suitably joined together. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0024]    Features, advantages, and technical and industrial significance of exemplary embodiments will be described below with reference to the accompanying drawings, in which like numerals denote like elements, and wherein: 
           [0025]      FIG. 1  is a sectional view illustrating a dissimilar material joining member according to a first embodiment; 
           [0026]      FIG. 2A  is a sectional view illustrating each step of a method for manufacturing a dissimilar material joined body using the dissimilar material joining member in  FIG. 1 , and shows a first step; 
           [0027]      FIG. 2B  is a sectional view illustrating each step of the method for manufacturing a dissimilar material joined body using the dissimilar material joining member in  FIG. 1 , and shows a second step; 
           [0028]      FIG. 2C  is a sectional view illustrating each step of the method for manufacturing a dissimilar material joined body using the dissimilar material joining member in  FIG. 1 , and shows a third step; 
           [0029]      FIG. 3  is a sectional view illustrating a dissimilar material joining member according to a second embodiment; 
           [0030]      FIG. 4A  is a sectional view illustrating a step of forming a through-hole in a first joining-object member by using the dissimilar material joining member in  FIG. 3 , and shows a state in which the dissimilar material joining member starts to press the first joining-object member; and 
           [0031]      FIG. 4B  is a sectional view illustrating the step of forming a through-hole in a first joining-object member by using the dissimilar material joining member in  FIG. 3 , and shows a state in which the dissimilar material joining member forms the through-hole in the first joining-object member. 
       
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     First Embodiment 
       [0032]    A dissimilar material joining member, a dissimilar material joined structure, and a method for manufacturing a dissimilar material joined body according to a first embodiment will be described by using  FIGS. 1 and 2A-2C .  FIG. 1  shows a sectional view of a dissimilar material joining member  12  according to the present embodiment in a state in which the dissimilar material joining member  12  is cut along an axial direction of the dissimilar material joining member  12 . Also,  FIGS. 2A, 2B, 2C  show sectional views of respective steps of a method for manufacturing a dissimilar material joined body  10  using the dissimilar material joining member  12 . 
         [0033]    As shown in  FIG. 1 , the dissimilar material joining member  12  has a dual structure in which an outer peripheral portion of the dissimilar material joining member  12  is composed of a first joining component  14  made of metal, and a center portion is composed of a second joining component  16  made of metal. The first joining component  14  is a constituent portion that can clinch a first joining-object member  18  (see  FIGS. 2A, 2B, 2C ) made of fiber reinforced resin (FRP), and the second joining component  16  is a constituent portion that can be spot-welded to a second joining-object member  20  (see  FIG. 2C ) made of metal (for example, made of steel). 
         [0034]    A fiber reinforced resin material forming the first joining-object member  18  shown in  FIGS. 2A, 2B, 2C  is a composite material (for example, a carbon fiber reinforced resin (CFRP) material) formed by bonding fibers (reinforcing fibers) with resin. The first joining-object member  18  is applied to, for example, a floor panel that constitutes a floor portion of a vehicle. Also, the second joining-object member  20  is applied to, for example, a rocker panel (also referred to as a “side sill”) that constitutes a lower end portion of both sides of a vehicle body. 
         [0035]    The first joining component  14  shown in  FIG. 1  includes a tubular portion  22  that is formed in a circular tube shape, and also includes a flange portion  24  that is extended in a flange shape to a radially outer side of the tubular portion  22  from one end in an axial direction (an upper end in the drawings) of the tubular portion  22 . Note that an axis of the tubular portion  22  is denoted by reference character CL in the drawings, The tubular portion  22  of the first joining component  14  is a portion that passes through the first joining-object member  18  (see  FIGS. 2A, 2B, 2C ). 
         [0036]    Also, in the tubular portion  22 , one end side in the axial direction (an upper side in the drawings) is a flange-side tubular portion  26  that is connected with the flange portion  24 , and the other end side in the axial direction (a lower side in the drawings) is a deformable portion  30  to be clinched. The flange-side tubular portion  26  is composed of a connection end portion  26 A that is connected with an inner peripheral side of the flange portion  24 , and a tube-shaped short-pipe portion  26 B that is connected with the connection end portion  26 A. In a usage state, the short-pipe portion  26 B is disposed on an inner peripheral side of a through-hole  18 A of the first joining-object member  18  as shown in  FIG. 2C . An axial length a (see  FIG. 1 ) of the short-pipe portion  26 B is set so as to match a length b in a plate thickness direction of the first joining-object member  18 . 
         [0037]    As shown in  FIG. 1 , a groove portion  34  having a V shape in section is formed on a proximal portion  30 A of the deformable portion  30  by cutting away an outer peripheral surface of the proximal portion  30 A over an entire periphery thereof. The groove portion  34  is provided for inducing bending of the deformable portion  30  during clinching (as a trigger for bending). The groove portion  34  is composed of a first tapered surface  34 A and a step surface  34 B. The first tapered surface  34 A is inclined toward a radially inner side of the tubular portion  22  as it extends away from a distal end edge side (the lower side in the drawings) of the deformable portion  30 . Also, the step surface  34 B is set to be perpendicular to the axial direction of the tubular portion  22 . In the first tapered surface  34 A and the step surface  34 B, respective end portions on the radially inner side of the tubular portion  22  are connected together. 
         [0038]    Also, a second tapered surface  36  is formed on a distal end portion  30 B of the deformable portion  30  by cutting away an outer peripheral surface of the distal end portion  30 B over an entire periphery thereof. The second tapered surface  36  is provided for inducing bending of the deformable portion  30  during clinching. The second tapered surface  36  is inclined toward the radially inner side of the tubular portion  22  as it extends toward the distal end edge side of the deformable portion  30 . 
         [0039]    The deformable portion  30  holds the first joining-object member  18  between the deformable portion  30  and the flange portion  24  by being bent such that a center portion in a direction along the axial direction of the tubular portion  22  is expanded toward the radially outer side of the tubular portion  22  to form a fold-back portion  30 X as shown in  FIG. 2B  when a compressive load with a predetermined value or more is inputted to the tubular portion  22  in the axial direction. 
         [0040]    That is, in the deformable portion  30  shown in  FIG. 1 , a portion connecting a formation portion of the groove portion  34  and a formation portion of the second tapered surface  36  is a bulging portion  38 , which is a portion bulging radially outward when the compressive load with a predetermined value or more is inputted to the tubular portion  22  in the axial direction. The bulging-scheduled portion  38  is a portion for ensuring a line length of a portion that is folded back when the compressive load is inputted to the tubular portion  22  in the axial direction. 
         [0041]    On the other hand, the second joining component  16  is fixed to the tubular portion  22  of the first joining component  14  in a state in which the second joining component  16  is coaxially inserted into the tubular portion  22 . The second joining component  16  is formed in a short circular cylindrical shape, and an axial length of the second joining component  16  is set according to an axial length of the first joining component  14  in a state after the first joining component  14  is subjected to clinching. Although illustration is omitted, the second joining component  16  is fixed to an inner peripheral surface of the short-pipe portion  26 B of the first joining component  14  with the short-pipe portion  26 B being pressurized from an outer peripheral surface side of the short-pipe portion  26 B and clinched after the second joining component  16  is inserted into the tubular portion  22  of the first joining component  14 . 
         [0042]    Note that a close contact region between an outer peripheral surface of the second joining component  16  and the inner peripheral surface of the short-pipe portion  26 B may extend over an entire region, or may be set intermittently in a circumferential direction (in other words, a portion projecting to the radially inner side may be set intermittently in the circumferential direction on the inner peripheral surface of the short-pipe portion  26 B). Also, for example, a fitting recessed portion may be previously formed in the outer peripheral surface of the second joining component  16  at a portion corresponding to the short-pipe portion  26 B of the first joining component  14 , and a portion of the inner peripheral surface of the short-pipe portion  26 B of the first joining component  14  may be fitted to the recessed portion of the outer peripheral surface of the second joining component  16  with the short-pipe portion  26 B being pressurized from the outer peripheral surface side and clinched after the second joining component  16  is inserted into the tubular portion  22  of the first joining component  14 . 
         [0043]    In the second joining component  16 , a first end surface  16 A that is exposed from an opening portion on the one axial end side (the upper side in the drawings) of the tubular portion  22  of the first joining component  14  is made flush with a surface of the flange portion  24 . A second end surface  16 B that is a surface opposite to the first end surface  16 A in the second joining component  16  is set at a position retracted inward from an opening portion on the other axial end side (the lower side in the drawings) of the tubular portion  22  of the first joining component  14 . To be more specific, the second end surface  16 B of the second joining component  16  is set on an inner side of the bulging portion  38 . 
         [0044]    As shown in  FIG. 2C , the second end surface  16 B (one axial end surface) of the second joining component  16  is spot-welded to the second joining-object member  20  made of metal in the present embodiment. Although the second end surface  16 B of the second joining component  16  is spot-welded to the second joining-object member  20  as one example in the present embodiment, the first end surface  16 A of the second joining component  16  may be spot-welded to the second joining-object member  20 . 
         [0045]    (Dissimilar material joined structure) Next, the dissimilar material joined structure in which the first joining-object member  18  made of resin and the second joining-object member  20  made of metal are joined together via the dissimilar material joining member  12  (having the first joining component  14  and the second joining component  16 ) will be described. In  FIG. 2C , the dissimilar material joined body  10  to which the dissimilar material joined structure is applied is shown between a pair of electrodes  40 ,  42  described later. 
         [0046]    The first joining component  14  made of metal includes a circular tube portion  28  as a tube portion passing through the first joining-object member  18 . The circular tube portion  28  is formed by the flange-side tubular portion  26  and one portion on the proximal portion  30 A of the deformable portion  30  shown in  FIG. 1 . Also, as shown in  FIG. 2C , the first joining component  14  includes the flange portion  24  that is extended in a flange shape to a radially outer side of the circular tube portion  28  from one axial end (the upper side in the drawings) of the circular tube portion  28 , and also includes a clinched portion  32  that is formed continuously to the other axial end of the circular tube portion  28 . 
         [0047]    The clinched portion  32  is extended in a flange shape to the radially outer side of the circular tube portion  28  from the other axial end of the circular tube portion  28  to hold the first joining-object member  18  between the clinched portion  32  and the flange portion  24 . The clinched portion  32  is also folded back to an opposite side to the flange portion  24  and to a radially inner side of the circular tube portion  28 , and a fold-back end portion  32 A of the clinched portion  32  is set at a position overlapping the circular tube portion  28  as viewed in the axial direction of the circular tube portion  28 . The clinched portion  32  is formed by a portion of the deformable portion  30  shown in  FIG. 1  other than one portion on the proximal portion  30 A. 
         [0048]    The second joining component  16  made of metal shown in  FIG. 2C  is formed in a short cylindrical shape, and is fixed to the circular tube portion  28  of the first joining component  14  in a state in which the second joining component  16  is coaxially inserted into the circular tube portion  28 . Also, the second joining-object member  20  made of metal is disposed facing the first joining-object member  18  made of resin, and the second end surface  16 B (one axial end surface) of the second joining component  16  is spot-welded to the second joining-object member  20 . The clinched portion  32  is interposed between the first joining-object member  18  and the second joining-object member  20 . 
         [0049]    (Operation and Effect of Method for manufacturing a dissimilar material joined body) Next, an operation and an effect of the above embodiment will be described by describing the method for manufacturing the dissimilar material joined body  10  (see  FIG. 2C ) using the dissimilar material joining member  12 . 
         [0050]    First, in a first step of the method for manufacturing the dissimilar material joined body  10  (see  FIG. 2C ), the flange portion  24  is brought into contact with the first joining-object member  18  made of resin and having a panel shape shown in FIG.  2 A by passing the tubular portion  22  of the first joining component  14  made of metal through the first joining-object member  18  in a state in which the first joining-object member  18  is supported by an unillustrated support portion. 
         [0051]    In the present embodiment, the tubular portion  22  of the first joining component  14  is passed through the through-hole  18 A that is previously formed in the first joining-object member  18  as one example, However, the first joining component  14  may be disposed as shown in  FIG. 2A  by, for example, punching the first joining-object member  18  by the distal end portion of the tubular portion  22  of the first joining component  14  to form the through-hole  18 A, and thereafter moving the first joining component  14  until the flange portion  24  of the first joining component  14  comes into contact with the first joining-object member  18 . 
         [0052]    In a second step after the first step, the pair of electrodes  40 ,  42  are disposed on opposite sides in the axial direction of the dissimilar material joining member  12 , and are moved in a direction in which the pair of electrodes  40 ,  42  approach each other by an unillustrated driving mechanism (see arrows m 1 , m 2 ) as shown in  FIG. 2B . One of the electrodes  40  stops at a position in contact with the first end surface  16 A of the second joining component  16 , and the other of the electrodes  42  keeps moving after coming into contact with the distal end portion of the deformable portion  30  of the first joining component  14 , and stops at a position in contact with the second end surface  16 B of the second joining component  16 . The pair of electrodes  40 ,  42  constitute a portion of a known electric clinching device, and input a compressive load with a predetermined value or more to the dissimilar material joining member  12  in the axial direction. 
         [0053]    That is, in the second step, the deformable portion  30  to be clinched of the dissimilar material joining member  12  is bent such that the center portion in the direction along the axial direction of the tubular portion  22  in the deformable portion  30  is expanded to the radially outer side of the tubular portion  22  to form the fold-back portion  30 X, and the first joining-object member  18  is held between the bent deformable portion  30  and the flange portion  24 . Accordingly, it is possible to fix the first joining component  14  to the first joining-object member  18  while suppressing local load input to the first joining-object member  18 . Also, since a distal-end opening portion  30 K of the deformable portion  30  is not increased in diameter (or is almost not increased in diameter) when the deformable portion  30  to be clinched is folded back and deformed as described above, a situation in which the distal-end opening portion  30 K of the deformable portion  30  cracks in the second step (that is, during clinching) can be avoided (or is highly likely to be avoided). 
         [0054]    In the second step, for example, a known pressing device may be used instead of the electric clinching device including the pair of electrodes  40 ,  42  to bend the deformable portion  30  by inputting the compressive load with a predetermined value or more to the dissimilar material joining member  12  in the axial direction. 
         [0055]    Also, as shown in  FIG. 1 , in the dissimilar material joining member  12  of the present embodiment, the first tapered surface  34 A described above is formed on the proximal portion  30 A of the deformable portion  30 , and the second tapered surface  36  described above is formed on the distal end portion  30 B of the deformable portion  30 , Therefore, when the compressive load with a predetermined value or more is inputted to the tubular portion  22  in the axial direction, a load along an inclination direction of the first tapered surface  34 A is applied to the proximal portion  30 A of the deformable portion  30 , and a load along an inclination direction of the second tapered surface  36  is applied to the distal end portion  30 B of the deformable portion  30 . The deformable portion  30  is deformed by the loads applied as described above so as to be bent to the radially outer side of the tubular portion  22  from the proximal portion  30 A, and be folded back at an intermediate portion between the proximal portion  30 A and the distal end portion  30 B of the deformable portion  30  (see  FIG. 2B ). 
         [0056]    Also, in the present embodiment, the step surface  34 B that is formed on the proximal portion  30 A of the deformable portion  30  forms the groove portion  34  having a V shape in section together with the first tapered surface  34 A, and is set to be perpendicular to the axial direction of the tubular portion  22 . Therefore, when the compressive load with a predetermined value or more is inputted to the tubular portion  22  in the axial direction, the deformable portion  30  can be stably bent along a direction perpendicular to the axial direction of the tubular portion  22  from the proximal portion  30 A. Therefore, when the deformable portion  30  is bent and deformed to the radially outer side of the tubular portion  22  as shown in  FIG. 2B , the first joining-object member  18  is stably held between the flange portion  24  and the deformable portion  30 . 
         [0057]    Next, in a third step after the second step, the second joining-object member  20  made of metal and having a panel shape is disposed facing the first joining-object member  18  by inserting the second joining-object member  20  between the dissimilar material joining member  12  and the electrode  42  as shown in  FIG. 2C  after retracting the electrode  42  in a direction in which the electrode  42  separates from the dissimilar material joining member  12 . In the third step, the second end surface  16 B (one axial end surface) of the second joining component  16  is spot-welded to the second joining-object member  20  by passing electricity between the pair of electrodes  40 ,  42  in a state in which the second joining component  16  and the second joining-object member  20  are held between the pair of electrodes  40 ,  42 . The pair of electrodes  40 ,  42  are moved in a direction in which the pair of electrodes  40 ,  42  separate from the second joining component  16  and the second joining-object member  20  by the unillustrated driving mechanism after the third step. 
         [0058]    Accordingly, the second joining-object member  20  made of metal can be joined to the first joining-object member  18  made of resin via the second joining component  16  and the first joining component  14 . That is, the dissimilar material joined body  10  according to the present embodiment is manufactured. 
         [0059]    Next, additional description of the dissimilar material joined body  10  having the dissimilar material joined structure manufactured by the above manufacturing method will be made. The clinched portion  32  of the first joining component  14  in the dissimilar material joined body  10  is folded back to the opposite side to the flange portion  24  and to the radially inner side of the circular tube portion  28  from a flange-shaped portion that holds the first joining-object member  18  between the flange-shaped portion and the flange portion  24 , and the fold-back end portion  32 A is set at a position overlapping the circular tube portion  28  as viewed in the axial direction of the circular tube portion  28 . That is, in such a configuration, a distal-end opening portion  32 K of the clinched portion  32  has about the same diameter as that of the circular tube portion  28 . Thus, it is not necessary (or it is almost not necessary) to increase the diameter of the distal-end opening portion  32 K of the clinched portion  32  during clinching. Therefore, when the dissimilar material joined body  10  is manufactured, a situation in which the distal-end opening portion  32 K of the clinched portion  32  cracks during clinching can be avoided (or is highly likely to be avoided). 
         [0060]    As described above, in accordance with the present embodiment, the second joining-object member  20  made of metal and the first joining-object member  18  made of resin can be suitably joined together. 
       Second Embodiment 
       [0061]    Next, a second embodiment will be described by using  FIG. 3  and  FIGS. 4A, 4B .  FIG. 3  shows a sectional view of a dissimilar material joining member  50  according to the present embodiment in a state in which the dissimilar material joining member  50  is cut along an axial direction of the dissimilar material joining member  50  (a sectional view corresponding to  FIG. 1  of the first embodiment). As shown in  FIG. 3 , the dissimilar material joining member  50  includes a first joining component  52  made of metal shown in  FIG. 3  instead of the first joining component  14  of the dissimilar material joining member  12  of the first embodiment shown in  FIG. 1 . The first joining component  52  has a configuration in which a punch portion  58  shown in  FIG. 3  is added to the distal end edge side of the deformable portion  30  of the first joining component  14  of the first embodiment shown in  FIG. 1 . The dissimilar material joining member  50  has substantially the same configuration as that of the dissimilar material joining member  12  of the first embodiment (see  FIG. 1 ) except for the punch portion  58 . Therefore, substantially the same constituent portions as those of the first embodiment are assigned the same reference numerals, and description thereof is omitted. 
         [0062]    Note that a tubular portion  54  of the present embodiment is composed of a portion corresponding to the tubular portion  22  of the first embodiment (see  FIG. 1 ) and the punch portion  58 . Also, a deformable portion  56  of the present embodiment is composed of a portion corresponding to the deformable portion  30  of the first embodiment (see  FIG. 1 ) and the punch portion  58 . 
         [0063]    The punch portion  58  is a portion for punching the first joining-object member  18  (see  FIGS. 4A, 4B ) in the plate thickness direction. A portion  58 A on a proximal end side of the punch portion  58  is set to the same wall thickness as that of a general portion (a portion that is not cut away (such as the short-pipe portion  26 B)) of the tubular portion  54 . The portion  58 A on the proximal end side of the punch portion  58  includes an end surface  58 S that forms a groove portion  60  having a V shape in section together with the second tapered surface  36 , and the end surface  58 S is set to be perpendicular to an axial direction of the tubular portion  54 . 
         [0064]    Also, a tapered surface  58 T is formed in a portion including a distal end portion  58 B of the punch portion  58  by cutting away an outer peripheral surface of the portion over an entire periphery thereof. The tapered surface  58 T is inclined toward a radially inner side of the tubular portion  54  as it extends toward a distal end edge side of the deformable portion  56 . A distal end position  58 T 1  of the tapered surface  58 T is located on the radially inner side of the tubular portion  54  with respect to a distal end position  36 S of the second tapered surface  36 . That is, an area of a distal end surface  56 Z of the deformable portion  56  is set to be smaller than an area of a distal end surface  30 Z of the deformable portion  30  in the first embodiment shown in  FIG. 1  in consideration of punching of the first joining-object member  18  (see  FIGS. 4A, 4B ). An inclination angle of the tapered surface  58 T shown in  FIG. 3  and a shape of the punch portion  58  are set in consideration of a load when the first joining-object member  18  (see  FIGS. 4A, 4B ) is punched and a load during clinching. 
         [0065]      FIGS. 4A, 4B  show sectional views of a step of forming the through-hole  18 A in the first joining-object member  18  by using the dissimilar material joining member  50  in  FIG. 3 . To be more specific,  FIG. 4A  shows a state in which the dissimilar material joining member  50  starts to press the first joining-object member  18 , and  FIG. 4B  shows a state in which the dissimilar material joining member  50  punches the first joining-object member  18  to form the through-hole  18 A. 
         [0066]    As shown in  FIG. 4A , the first joining-object member  18  is supported by a circular tube-shaped support base  48  on an outer peripheral side of a portion where the through-hole is to be formed. The dissimilar material joining member  50  is disposed on an upper side of the first joining-object member  18  with the punch portion  58  being directed toward the first joining-object member  18 . The dissimilar material joining member  50  is pressed from the upper side by a punch  46  (see an arrow f). Accordingly, the punch portion  58  of the dissimilar material joining member  50  (the first joining component  52 ) punches the first joining-object member  18  to form the through-hole  18 A in the first joining-object member  18  as shown in  FIG. 4B . Note that a portion punched from the first joining-object member  18  is denoted by reference character  1813  in the drawings. 
         [0067]    Here, a method for manufacturing a dissimilar material joined body using the dissimilar material joining member  50  will be briefly described. In the present embodiment, the dissimilar material joining member  50  of the present embodiment is used instead of the dissimilar material joining member  12  in the first embodiment (see  FIG. 1 ), and a method similar to the method for manufacturing the dissimilar material joined body  10  shown in  FIGS. 2A, 2B, 2C  is applied. Accordingly, a dissimilar material joined body (not shown) which is almost the same as the dissimilar material joined body  10  in the first embodiment and to which the dissimilar material joined structure is applied can be manufactured. 
         [0068]    The first to third steps (see  FIGS. 2A to 2C ) can be performed subsequent to the step in  FIG. 4B  since the electrode  42  shown in  FIG. 2B  can be disposed inside a tube of the support base  48  shown in  FIGS. 4A, 4B  after the step in  FIG. 4B  when an opening diameter of the support base  48  is set to be slightly larger. 
         [0069]    In accordance with the configuration of the present embodiment, substantially the same operation and effect as those of the first embodiment described above can be obtained. 
       Supplementary Explanation of the Embodiments 
       [0070]    In the dissimilar material joining members  12 ,  50  of the above embodiments, the tubular portions  22 ,  54  are formed in a circular tube shape, and the second joining component  16  is formed in a short circular cylindrical shape. Although such a configuration is more preferable, for example, the tubular portion may be formed in a rectangular tube shape, and the second joining component may be formed in a short rectangular cylindrical shape. Similarly, in the dissimilar material joined structure of the above first embodiment, the tube portion of the first joining component  14  is the circular tube portion  28 . However, the tube portion of the first joining component may be a rectangular tube portion. 
         [0071]    Also, as a modification of the above embodiments, a groove-shaped portion that is cut away over an entire periphery may be formed in the center portion between the proximal portion and the distal end portion in an inner peripheral surface of the deformable portions  30 ,  56  of the first joining components  14 ,  52  in order to induce bending of the deformable portions  30 ,  56  during clinching in addition to the above configuration. 
         [0072]    Also, as a modification of the above embodiments, an outer peripheral surface of the deformable portion of the first joining component may be formed in a curved shape that is set so as to have a larger diameter (be increased in diameter) gradually toward the center portion between the proximal portion and the distal end portion. 
         [0073]    Also, in the above embodiments, the step surface  34 B forming the groove portion  34  having a V shape in section together with the first tapered surface  34 A is set to be perpendicular to the axial direction of the tubular portions  22 ,  54  in the proximal portion of the deformable portions  30 ,  56 . Although such a configuration is more preferable, for example, the surface forming the groove portion together with the first tapered surface in the proximal portion of the deformable portion may be set to be slightly inclined with respect to the direction perpendicular to the axial direction of the tubular portion. 
         [0074]    Also, in the above first embodiment, the case in which the first joining-object member  18  is applied to a floor panel, and the second joining-object member  20  is applied to a rocker panel has been described as one example. However, the first joining-object member and the second joining-object member may be applied to other members such as a constituent member of a vehicle side door. 
         [0075]    The above embodiments and the above plurality of modifications may be appropriately combined together and carried out. 
         [0076]    Although examples have been described above, the embodiments can be variously modified.