JP2018176235A - Rivet joining mold - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrict cracking in a member to be joined that is closest to a rivet joining mold, when joining together plural members to be joined with a self-pierce rivet.SOLUTION: A cavity bottom surface 21 of a cavity 20 disposed on one side in an axial direction of a mold body part 2 of a rivet joining mold 1, is shaped to protrude toward the one side in the axial direction, so that a center 24 of the cavity bottom surface or a center vicinity part 27 including the center 24 is positioned nearest to the one side in the axial direction. An outer end part 25 of the cavity bottom surface 21, and the center 24 of the cavity bottom surface 21 or the center vicinity part 27 are connected from the outer end part 25 toward the center 24 of the cavity bottom surface 21 or the center vicinity part 27, by inclined planes 26 and 28 inclined to the one side in the axial direction.SELECTED DRAWING: Figure 3

Description

  BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to a riveting mold for joining a plurality of members to be joined together with a self-piercing rivet.

  Heretofore, in order to join a plurality of members to be joined, a self-piercing rivet may be used, and in the case of joining by the self-piercing rivet, a rivet bonding die is used.

  In the rivet joint mold described in Patent Document 1, a base main body that abuts on a mold side joint member which is a joint member closest to the mold among a plurality of joint members when joining using a self-piercing rivet A recess is formed in the base body to allow expansion deformation of the die-side joined member by driving the self-piercing rivet, and an annular ridge is formed in a central region of the bottom of the recess. A department is provided.

  Further, in the rivet bonding mold described in Patent Document 1, when the self-piercing rivet is driven, the mold-side joined member extends from the inner side in the radial direction to the outer side in the radial direction than the raised portion. Outflow is suppressed by the ridges.

JP-A-2015-529562

  By the way, when joining a plurality of to-be-joined members by a self-piercing rivet, in the part where the self-piercing rivet is driven in the plurality of to-be-joined members, A riveting die is placed, and a self-piercing rivet is driven into the plurality of members to be joined toward the riveting die.

  Generally, in a die for riveting, expansion of a member to be joined (hereinafter referred to as a die-side member to be joined) closest to the die for riveting among a plurality of members to be joined by driving a self-piercing rivet. Since the recessed cavity is provided to allow the ejection deformation, when the self-piercing rivet is driven into the plurality of members to be joined, the mold side member to be joined bulges and deforms into the cavity. And while the leg part of a self-piercing rivet penetrates to-be-joined members other than the said mold side to-be-joined member, the said some to-be-joined members are joined by biting in in the said mold side to-be-joined member. Further, when the leg portion of the self-piercing rivet bites into the mold-side joined member, the leg portion is deformed so as to expand in diameter, whereby the plurality of joined members are firmly joined.

  However, according to the study of the inventors of the present invention, when the self-piercing rivet is punched into the plurality of members to be joined in order to join the plurality of members to be joined by the self-piercing rivet, It was found that cracking may occur.

  Further, when the inventors of the present invention further studied, the crack of the die-side joined member corresponds to a portion corresponding to the leg portion of the self-piercing rivet in the die-side joined member (hereinafter referred to as a leg portion) When it is intended to stretch and deform radially outward of the cavity in the cavity, the elongation may be caused by the rivet jointing mold, specifically, the portion constituting the cavity in the rivet jointing mold. It is the cause that the deformation is suppressed and both the driving load from the self-piercing rivet and the repulsive load from the side wall constituting the cavity are input to the leg corresponding portion of the above-mentioned mold side joined member I found that.

  In patent document 1, the outflow of the mold side to-be-joined member at the time of driving in a self-piercing rivet is suppressed by the cyclic | annular protuberance. However, in the rivet joint mold of Patent Document 1, the deformation of the leg corresponding portion of the mold side joined member is restrained by the annular protuberance, and the mold side joined member is formed from the annular protuberance. As a result of the repulsion load being input to the leg portion corresponding portion, cracks may occur in the mold-side workpiece.

  This invention is made in view of such a point, The place made into the objective is the metal for riveting joining among several to-be-joined members, when joining several to-be-joined members by a self-piercing rivet. For riveting, it is possible to suppress the deformation of the mold side joining member which is the closest joint member to the mold as much as possible, and to suppress the occurrence of cracks in the mold side joining member It is to provide a mold.

  In order to solve the above problems, the present invention relates to bonding together a plurality of members to be joined with a self-piercing rivet having substantially cylindrical legs in a state in which the plurality of members to be joined are stacked. The end face of one side of the plurality of members to be joined is an axial end face of a rivet bonding mold disposed on the side opposite to the self-piercing rivet in the portion where the self-piercing rivet is driven. A pillar-shaped die main body portion is in contact with the die-side joined member which is the above-mentioned joined member closest to the above-mentioned die, and the above-mentioned die main body portion In order to allow bulging deformation of the mold side joining member to the other side in the axial direction due to the driving of the self-piercing rivet in the portion excluding the peripheral portion, the end face is directed to the other side in the axial direction. I was depressed, The cavity has a circular shape as viewed from the axial direction, and the cavity is constituted by a cavity bottom surface circular as viewed from the axial direction and a cavity side surface, and the cavity bottom surface is a center of the cavity bottom surface. Alternatively, it has a shape projecting toward the one side in the axial direction so that a portion near the center including the center is located on the one side in the axial direction, passing through the center of the bottom of the cavity and In a cross section obtained by cutting the mold body with the plane extending in the axial direction, the outer end which is the radial outer end of the cavity bottom, and the center of the cavity bottom or the vicinity thereof It is connected by the sloped surface part which inclined to the said one side of the said axial direction toward the center of the said cavity bottom face or the said center vicinity from an outer side edge part, It was.

  According to this configuration, when the plurality of members to be joined are joined together by the self-piercing rivet, it is possible to suppress the occurrence of cracks in the die-side joined member.

  Specifically, since the mold main body portion is provided with a cavity which is recessed to allow expansion deformation to the other side of the mold-side joined member in the axial direction, the plurality of joined members can be obtained. In the superposed state, when the self-piercing rivet is driven into the plurality of members to be joined toward the rivet bonding die, the plurality of members to be joined bulge out into the cavity of the die main body. Transform into At this time, a portion (hereinafter referred to as a leg portion corresponding portion) corresponding to the leg portion of the self-rears rivet in the die-side joined member is stretched and deformed radially outward of the bottom surface of the cavity. Further, in the die-side joined member, a portion on the inner side in the radial direction (hereinafter referred to as an inner deformation portion) of the leg portion is also stretched and deformed to the outer side in the radial direction as in the leg portion corresponding portion. Ru. On the other hand, in the die-side joined member, the radial direction is more than the boundary portion between the cavity side surface and the end surface of the mold main body in the axial direction on the outer side than the leg in the radial direction. An inner portion (hereinafter referred to as an outer deformation portion) is bent and deformed toward the other side in the axial direction.

  Further, the bottom surface of the cavity has a shape projecting toward the one side in the axial direction such that the center of the bottom surface of the cavity or a portion near the center including the center is located most on the one side in the axial direction. In the cross section of the mold body cut through the center of the bottom of the cavity in the plane passing through the center of the bottom of the cavity, the outer end of the bottom of the cavity and the center or near central portion of the bottom of the cavity are the outer ends of the bottom of the cavity Since the part is connected to the center of the cavity bottom surface or to a part near the center by the inclined surface part inclined to the one side in the axial direction, as described above, the mold-side joined member moves into the cavity When it is deformed so as to bulge, the inner deformation portion and the leg portion corresponding portion of the mold side bonding member abut on the cavity bottom surface earlier than the outer deformation portion of the mold side bonding member. On the other hand, when the inner deformation portion and the leg corresponding portion start to abut on the cavity bottom surface, the outer deformation portion of the die-side joined member is not yet in contact with the cavity bottom surface and the cavity side surface. Thus, a gap is formed between the mold-side workpiece and the radially outer portion of the inclined surface portion of the bottom surface of the cavity.

  From the above state, when the self-piercing rivet is further driven toward the riveting mold, the mold-side joined member is further deformed so as to bulge into the cavity. At this time, the leg corresponding portion of the die-side joined member is extended and deformed to the outside in the radial direction. This is because deformation of the leg corresponding portion is allowed by the gap. The inner deformation portion of the mold-side workpiece also extends and deforms in the radial direction in the same manner as the leg portion corresponding portion. The outer deformation portion of the mold side joined member moves so as to be pushed outward in the radial direction along with the elongation deformation of the leg portion corresponding portion, and is bent and deformed to the other side in the axial direction. Be done.

  From the above state, when the self-piercing rivet is further driven toward the riveting mold, the leg portion of the self-piercing rivet penetrates the members to be joined other than the mold-side joined member. Thereafter, when the self-piercing rivet is further driven, the leg portion of the self-piercing rivet bites into the mold side workpiece while being deformed so as to expand in diameter radially outward by the repulsive load from the rivet bonding mold. . At this time, the inner deformation portion and the leg portion corresponding portion of the die-side joined member are expanded and deformed in the radial direction as the leg portion is deformed. On the other hand, the outer deformation portion of the mold-side joined member is further bent and deformed to the other side in the axial direction and is slightly pushed outward in the radial direction by the biting of the leg portion.

  Therefore, in the rivet joint mold of the present invention, when the leg corresponding portion of the mold side joint member abuts on the cavity bottom surface, the radial outer side of the mold side joint member and the inclined surface portion of the cavity bottom surface A gap is formed between the lower portion and the second portion to allow deformation of the leg corresponding portion. Thereby, when joining a plurality of members to be joined together by the self-piercing rivet, it is possible to suppress the deformation of the die-side members to be restrained as much as possible, and as a result, the die-side members to be joined Cracking can be suppressed.

  In the riveting mold, the height of the center of the bottom of the cavity from the deepest position of the cavity is set to a height greater than 30% with respect to the depth of the cavity at the deepest position of the cavity It is desirable that it is done.

  That is, in order to appropriately prevent the cracking of the die-side joined member, a gap as large as possible is formed between the die-side joined member and the radially outer portion of the inclined surface portion of the bottom surface of the cavity. It needs to be formed. Therefore, by setting the height of the center of the bottom of the cavity from the deepest position of the cavity to a height greater than 30% with respect to the depth of the cavity at the deepest position of the cavity, the self piercing rivet is obtained. When the inner deformation portion and the leg portion corresponding portion of the mold side bonding member abut against the cavity bottom surface by driving into the plurality of members to be bonded, the radial direction of the mold side bonding member and the inclined surface portion of the cavity bottom surface A gap as large as possible is formed between the outer part. As a result, the leg portion corresponding portion is easily deformed, and it is possible to effectively suppress the occurrence of a crack in the mold side bonded member.

  In one embodiment of the riveting mold, the bottom surface of the cavity has a spherical shape such that the center of the bottom surface of the cavity is at the top, and the inclined surface portion of the bottom surface of the cavity is the outer end and the above It is an inclined curved surface which connects with the top.

  According to this configuration, when the self-piercing rivet is driven into the plurality of members to be joined, and the inward deformation portion and the leg corresponding portion of the mold side adhesion member abut against the cavity bottom surface, the inward deformation portion and the legs Since the corresponding portion can be appropriately deformed along the inclined surface portion, it is possible to more appropriately suppress the occurrence of a crack in the mold side bonded member.

  In addition, since no sharp portion is present on the bottom of the cavity, the bottom of the cavity does not bite into the mold-side workpiece, and cracking of the mold-side workpiece can be more effectively suppressed.

  In the riveting mold, it is desirable that the side surface of the cavity is inclined outward in the radial direction from the outer end of the bottom surface of the cavity toward the one side in the axial direction.

  As a result, when the leg portion of the self-piercing rivet is deformed so as to expand in diameter, the outer deformation portion of the die-side joined member is easily pushed outward in the radial direction. As a result, it is possible to more appropriately suppress the restraint of the deformation of the die-side to-be-joined member, and it is possible to more effectively suppress the occurrence of cracks in the die-side to-be-joined member.

  As described above, according to the rivet bonding mold of the present invention, the bottom surface of the cavity formed on the end surface on one side in the axial direction of the mold body portion is the center of the bottom surface or the center And a shape projecting toward the one side in the axial direction so that a portion near the center including the second end is located most on the one side in the axial direction, passing through the center of the bottom of the cavity and in the axial direction In a cross section obtained by cutting the mold main body with an extending plane, an outer end which is an outer end of the cavity bottom in the radial direction and a center of the cavity bottom or a portion near the center are from the outer end A plurality of self-piercing rivets, since they are connected by the inclined surface portion inclined to the one side in the axial direction toward the center of the bottom surface of the cavity or the vicinity of the center When joining the workpieces together, the deformation of the mold-side workpieces may be suppressed as much as possible to be bound, it is possible to suppress cracks from occurring in the mold side members to be joined.

It is the perspective view which looked at the metal mold | die for rivet connection which concerns on Embodiment 1 of this invention from diagonally upper side. It is the top view which looked at the said metal mold | die for rivet connection from the upper side. FIG. 3 is an enlarged cross-sectional view enlarging a portion around a cavity in a mold body section cut along line III-III in FIG. 2; It is a side view of a self-piercing rivet. A cross-sectional view showing a state in which the rivet joint die, the self-piercing rivet and the two members to be joined are arranged in order to join two members to be joined with the self-piercing rivet using the rivet joint die It is. FIG. 6 is a cross-sectional view showing a state in which the self-piercing rivet is driven toward the riveting mold from the state of FIG. 5; FIG. 7 is a cross-sectional view showing a state in which the self-piercing rivet is further driven toward the riveting mold from the state of FIG. 6; It is sectional drawing which shows the state which joining of the said 2 to-be-joined members by the said self-piercing rivet was completed. It is the FIG. 3 equivalent view which shows the modification of the said metal mold | die for rivet connection.

  FIG. 1 shows a rivet bonding mold 1 (hereinafter simply referred to as a mold 1) according to an embodiment of the present invention. The mold 1 is a mold used when joining a plurality of plate-like members 60 to be joined (see FIGS. 5 to 8) by a self-piercing rivet 50 (see FIG. 4; hereinafter referred to as SPR 50). .

  The mold 1 includes a cylindrical mold body 2 and a cylindrical mold shank 3 having a smaller diameter than the mold body 2. The mold body 2 and the mold shank 3 are integrally formed so as to be coaxial. The diameters of the mold body 2 and the mold shank 3 are set to values according to the size of the SPR 50 (see FIG. 4) used for bonding. In addition, since the mold 1 is disposed so that the mold body 2 is on the upper side and the mold shank 3 is on the lower side in the use state, in the following description, according to the use state, the mold The side opposite to the mold shank 3 in the axial direction of the main body 2 is referred to as the upper side (corresponding to one side in the axial direction), and the mold shank 3 side is referred to as the lower side (corresponding to the other side in the axial direction).

  The upper surface 10, which is the upper end face of the mold body 2 (that is, the end face on one side in the axial direction), is a gold when joining the members 60 to be joined by SPR 50, as shown in FIGS. This surface is in contact with the mold side joined member 61 which is the joined member 60 closest to the mold 1. At the corner between the upper surface 10 and the side surface 11 of the mold body 2, as shown in FIGS. 1 and 2, a chamfer 12 is formed over the entire periphery of the upper surface 10.

  As shown in FIGS. 1 and 2, a cavity 20 recessed downward from the upper surface 10 is formed in a part of the upper surface 10, specifically, a portion of the upper surface 10 excluding the peripheral portion. The cavity 20 has a circular shape when viewed from the axial direction as shown in FIG. In the present embodiment, the cavity 20 is formed to be coaxial with the mold body 2. The detailed configuration of the cavity 20 will be described later.

  The SPR 50 is made of, for example, chromium molybdenum steel, and has a rivet head 51 and a leg 52 provided continuously from the rivet head 51, as shown in FIG. The leg 52 has a cylindrical shape having a diameter smaller than that of the rivet head 51, and the side opposite to the rivet head 51 in the cylinder axial direction (consistent with the central axial direction of the entire SPR 50) is released. The length in the cylinder axial direction of the leg 52 is set in accordance with the total thickness of the plurality of members to be joined 60. The leg portion 52 does not have to be strictly cylindrical, and may have, for example, a C-shaped shape as viewed from the cylinder axis direction, and two U-shaped ones have a U-shaped opening relative to each other. It may be shaped to be disposed opposite to each other.

  The leg 52 is, as shown in FIG. 4, a leg base 52a extending in the axial direction of the cylinder with a constant thickness, and the rivet head from the end of the leg base 52a opposite to the rivet head 51. And 51 has a leg tip 52b that tapers toward the opposite side. More specifically, in the leg tip 52b, the radially outer portion extends straight along the cylinder axis direction, while the radially inner portion faces away from the rivet head 51. The diameter is gradually increased, and the thickness is gradually reduced toward the outer side in the radial direction. When the SPR 50 is driven into the joined member 60 by the shape of the leg 52 as described above, the leg 52 is deformed to expand radially outward, and the deformed The members 52 to be joined are firmly joined together by the legs 52.

  Here, when the plurality of members to be joined 60 are actually joined by the SPR 50, as shown in FIG. 5, the SPR 50 and the mold 1 are joined to each other in a state where the plurality of members to be joined 60 are overlapped. Each of the members 60 is disposed to face each other with the member 60 interposed therebetween, and the SPR 50 is driven into the plurality of members to be joined 60 toward the mold 1. At this time, the plurality of members to be joined 60 deform so as to bulge into the cavity 20. In other words, the cavity 20 is a cavity that allows the SPR 50 to cause a bulging deformation to the lower side (that is, the other side in the axial direction) of the plurality of joined members 60 (in particular, the die side joined member 61) by driving. .

  Then, in the state where the bonding by the SPR 50 is completed, as shown in FIG. 8, the leg base 52 a of the SPR 50 penetrates the members to be joined 60 other than the mold side joined member 61 and the leg tip 52 b of the SPR 50 Is in a state of biting into the mold side workpiece 61.

  As described above, when joining together a plurality of joined members 60 by SPR 50, the deformation of the die-side joined member 61 when the SPR 50 is driven is restrained by the die 1, and the die-side joined member 61 May crack. In particular, in the case where the mold-side workpiece 61 is made of aluminum or a material whose indentation hardness is equal to or less than the indentation hardness of aluminum, the possibility of occurrence of cracking is even higher. When a crack occurs in the mold side bonded portion 61, the bonded member 60 may be corroded from the portion of the crack. For this reason, it is necessary to prevent the said crack appropriately.

  Therefore, in the present embodiment, by devising the shape in the cavity 20 in the mold 1, cracking of the mold-side joined member 61 is prevented. Hereinafter, the detailed configuration of the cavity 20 will be described.

  As shown in FIGS. 2 and 3, the cavity 20 is constituted by a cavity bottom 21 and a cavity side 30 which are circular when viewed from the axial direction.

  The diameter at the open end of the cavity 20 is determined corresponding to the diameter of the leg 52 of the SPR 50. Specifically, the leg 52 of the SPR 50 is the gold of the plurality of members 60 to be joined. It is set to an appropriate value such that it is easy to penetrate the members to be joined other than the mold-side members to be joined 61 and to be easily deformed so as to expand in diameter.

  In the present embodiment, as shown in FIG. 3, the cavity bottom surface 21 is shaped so as to protrude upward so that the center in the radial direction is located at the uppermost side. More specifically, the cavity bottom 21 has a spherical shape such that the center 24 of the cavity bottom 21 is at the top. Thereby, as shown in FIG. 3, in the cross section which cut | disconnected the metal mold | die part 2 by the plane which passes along the center of the cavity bottom face 21, and is extended in the said axial direction, the cavity bottom 21 becomes circular.

  Further, in the cross section obtained by cutting the mold body 2 along a plane passing through the center of the cavity bottom 21 and extending in the axial direction, the outer end 25 and the center 24 of the cavity bottom 21 extend from the outer end 25 to the cavity bottom 21. It is connected by the inclined surface 26 which inclines upwards toward the center 24 of. The inclined surface portion 26 is an inclined curved surface as shown in FIG. Further, the portion of the inclined surface portion 26 in the vicinity of the outer end 25 has a gentle inclination so as to be continuous with the outer end 25.

  The cavity side surface 30 is inclined outward in the radial direction from the radial outer end of the cavity bottom surface 21 (strictly, the outer end 25 of the cavity bottom surface 21), as shown in FIG. It extends. More specifically, as shown in FIG. 3, in the cross section cut along the radial direction, the cavity side surface 30 has an upper side surface portion 31 having an inclined curved surface continuous with the upper surface 10, and the outer end A lower side surface portion 32 extending to connect the portion 25 and the lower end of the upper side surface portion 31 is provided. The lower side surface portion 32 is, for the most part, an inclined plane, and the vicinity of the outer end 25 is an inclined curved surface continuous with the outer end 25.

  The portion near the outer end 25 of the inclined surface 26 of the bottom surface 21 of the cavity has a gentle inclination so as to be continuous with the outer end 25, and the lower side 32 of the cavity side 30 is the outer end. As shown in FIG. 3, the bottom surface 21 and the side surface 30 of the cavity are recessed so that the position of the outer end portion 25 is located at the lowermost position, since the inclined surface is continuous to 25. It is continuous by the curved surface.

  In the present embodiment, the height H of the center of the cavity bottom 21 from the deepest position of the cavity 20 is set to a height greater than 30% with respect to the depth D of the cavity 20 at the deepest position of the cavity 20. ing. In this embodiment, since the deepest position of the cavity 20 is the position of the outer end 25, the height H of the center 24 of the cavity bottom 21 from the outer end 25 is the cavity 20 at the position of the outer end 25. The height is set to be greater than 30% with respect to the depth D of.

  Next, referring to FIGS. 5 to 8, movements of the SPR 50 and the two joined members 60 when the two joined members 60 are joined by the SPR 50 using the mold 1 according to the first embodiment. Will be explained. In the following description, of the two members 60 to be joined, the member on the side where the SPR 50 is disposed at the time of joining operation is called the rivet side member 62 (the mold side and the rivet side members 61 and 62 are distinguished) When it is not necessary, it is simply referred to as a bonded member 60). In the first embodiment, the die-side joined member 61 is a plate made of an aluminum plate or an aluminum alloy, and the rivet-side joined member 62 is a steel plate. Also, although detailed description is omitted, the actual joining operation is performed using a general riveting apparatus.

  When joining two members to be joined 60 by SPR 50, first, as shown in FIG. 5, with the die-side joined member 61 and the rivet-side joined member 62 overlapped, the die-side Both the members to be joined 61 and 62 are disposed such that the joining member 61 and the upper surface 10 of the mold 1 abut. Next, as shown in FIG. 5, the SPR 50 is disposed to face the mold 1 with the members to be joined 61 and 62 interposed therebetween. That is, the mold 1 is in the state where it is disposed on the side opposite to the side to which the SPR 50 is driven in the portion where the SPRs 50 in the plurality of (two in this case) bonding members 60 are driven. At this time, as shown in FIG. 5, the inclined surface 26 of the mold 1 is positioned at a position corresponding to the leg 52 of the SPR 50. In practice, since the above riveting apparatus is provided with a guide for determining the position of the mold 1 and a guide for guiding the placement and the direction of the SPR 50, the mold 1 and the SPR 50 can be arranged according to each guide. For example, the mold 1 and the SPR 50 are in a positional relationship as shown in FIG.

  When the SPR 50 is driven toward the mold 1 from the state of FIG. 5, both the members to be joined 61 and 62 deform so as to expand into the cavity 20, as shown in FIG. At this time, a portion corresponding to the leg portion 52 of the SPR 50 in the mold-side joined member 61 (hereinafter, referred to as a leg portion corresponding portion 61 a) is stretched and deformed outward in the radial direction of the cavity bottom surface 21. Further, a portion (hereinafter referred to as an inner deformation portion 61c) on the inner side in the radial direction of the leg portion 52 in the mold side joined member 61 also extends in the radial direction in the same manner as the leg portion corresponding portion 61a. It is transformed. On the other hand, in the die-side joined member 61, a portion outside the radial direction with respect to the leg 52 and inside the radial direction with respect to the boundary portion between the cavity side surface 30 and the upper surface 10 of the die main body 2 (Hereinafter, the outer deformation portion 61b) is bent and deformed downward.

  When the SPR 50 is further driven toward the mold 1 from the state of FIG. 6, the rivet-side joined member 62 is broken by the leg portion 52 of the SPR 50 as shown in FIG. 7. On the other hand, the mold side joined member 61 is further deformed so as to bulge into the cavity 20. At this time, the inner deformation portion 61 c of the mold side joined member 61 is bent and deformed along the spherical shape of the cavity bottom surface 21. The leg corresponding portion 61a of the mold side joined member 61 is slightly extended and deformed to the outside in the radial direction. On the other hand, the outer deformation portion 61c of the mold side joined member 61 moves so as to be pushed outward in the radial direction along with the elongation deformation of the leg portion corresponding portion 61a and bends downward. It is transformed.

  Further, as shown in FIG. 7, in a state where the inner deformation portion 61 c and the leg portion corresponding portion 61 a of the mold side joining member 61 abut on the cavity bottom face 21, the mold side joining member 61 and the cavity bottom face 21. A gap is formed between the above-mentioned radially outer portion of the inclined surface portion 26.

  When the SPR 50 is further driven toward the mold 1 from the state of FIG. 7, as shown in FIG. 8, the leg portion 52 of the SPR 50 is expanded radially outward by the repulsive load from the mold 1. And bite into the mold side joined member 61. At this time, the inner deformation portion 61 c and the leg portion corresponding portion 61 a of the mold-side workpiece 61 expand and deform in the radial direction with the deformation of the leg portion 52. This is because deformation of the leg corresponding portion 61a is permitted by the gap. On the other hand, the outer deformation portion 61b of the mold side joined member 61 is further bent and deformed toward the lower side so as to fill the gap, and the bit portion of the leg portion 52 slightly bites the outer side in the radial direction. Pushed out. Then, as shown in FIG. 8, if the SPR 50 is driven to such an extent that the leg 52 of the SPR 50 is embedded in both joined members 61 and 62, the rivet side joined member 62 and the mold side joined by SPR 50 Bonding with the member 61 is completed.

  As described above, the joining of the rivet-side joined member 62 and the mold-side joined member 61 by the SPR 50 is completed. According to the mold 1 of the first embodiment, when the leg corresponding portion 61 a of the mold side joined member 61 abuts on the cavity bottom surface 21, the mold side joined member 61 and the inclined surface portion 26 of the cavity bottom 21. A gap is formed between the radial portion and the radially outer portion to allow deformation of the leg corresponding portion 61a. Thereby, when joining a plurality of members to be joined 60 with each other by SPR 50, it is possible to suppress the deformation of the die side member to be joined 61 as much as possible, and as a result, the members on the die side It is possible to suppress the occurrence of cracks in 61.

  Here, when the height H of the center 24 of the cavity bottom 21 from the deepest position of the cavity 20 is too low, when the leg corresponding portion 61 a of the mold side joined member 61 abuts on the cavity bottom 21, The gap of a sufficient size is not formed between the mold-side workpiece 61 and the radially outer portion of the inclined surface 26 of the bottom surface 21 of the cavity. Therefore, in the present embodiment, the height H of the center 24 of the cavity bottom 21 from the deepest position of the cavity 20 (the position of the outer end 25 of the cavity bottom 21) is the height H of the cavity 20 at the deepest position. The height is set to be greater than 30% with respect to the depth D.

  Further, in the present embodiment, since the cavity bottom 21 has a spherical shape such that the center 24 of the cavity bottom 21 is at the top, when the SPR 50 is driven into a plurality of members to be joined 60, the mold side The inner deformation portion 61 c and the leg portion corresponding portion 61 a of the joined member 61 can be appropriately deformed along the cavity bottom surface 21. Thereby, it is possible to appropriately suppress the occurrence of a crack in the mold side bonded member 61. In addition, since no sharp portion is present on the cavity bottom surface 21 and the cavity bottom surface 21 does not bite into the mold side joining member 61, it is possible to more effectively suppress cracking of the mold side joining member 61. .

  Furthermore, in the first embodiment, since the cavity side surface 30 is inclined upward from the radial outer end of the cavity bottom 21 toward the upper side, the SPR 50 is driven toward the mold 1 In particular, when the leg 52 of the SPR 50 bites into the mold-side joined member 61 when being deformed, the deformation of the outer deformation portion 61 b of the mold-side joined member 61 is less likely to be restrained by the cavity 30, The portion 61 is appropriately pushed outward in the radial direction. Thereby, the repulsive load from the cavity side surface 30 can be appropriately received and it can suppress appropriately that a crack arises in the mold side to-be-joined member 61. As shown in FIG.

  Therefore, in the first embodiment, the mold main body 2 is provided with a cylindrical mold main body 2 whose end face (upper surface 10) on one side (upper side) in the axial direction is in contact with the mold joined member 61. From the end face to the other side in the axial direction so as to allow expansion deformation to the other side of the axial direction of the mold side joined member 61 due to the driving of the SPR 50 in the portion excluding the peripheral edge portion of the end face The cavity 20 has a cavity 20 which is concave toward the axis and circular as viewed from the axial direction, and the cavity 20 has a cavity bottom surface 21 circular from the axial direction and a flat portion (inclined flat portion 32). The cavity bottom surface 21 has a shape projecting toward the one side in the axial direction so that the center in the radial direction is located on the one side in the axial direction most, Go through the center of the cavity bottom 21 In the cross section obtained by cutting the mold body 2 at the plane extending in the axial direction, the outer end 25 and the center of the cavity bottom 21 move from the outer end 25 toward the center of the cavity bottom in the axial direction. Since it is connected by the inclined surface part 26 inclined to one side, when joining a plurality of joined members 60 by SPR 50, it is a joined member closest to the metal mold for riveting among a plurality of joined members It is possible to suppress the deformation of the mold-side workpieces as much as possible and to suppress the generation of cracks in the mold-side workpieces 61.

  FIG. 9 shows a modification of this embodiment, and in this modification, the cavity bottom 21 has a shape in which the portion 27 near the center including the center of the bottom 21 of the cavity is projected at the top. .

  The central vicinity portion 27 is a flat surface extending in the direction orthogonal to the axial direction. Although illustration is omitted, the central vicinity portion 27 has a circular shape when viewed from the axial direction.

  Further, the central vicinity portion 27 and the outer end portion 25 are connected by the inclined surface portion 28. Most of the inclined surface portion 28 forms an inclined plane, and a portion between the inclined surface portion 28 and the near center portion 27 is an inclined curved surface continuous with the near center portion 27. Further, a portion of the inclined surface portion 28 in the vicinity of the outer end 25 of the cavity bottom 21 is an inclined curved surface continuous with the outer end 25.

  As a result, as shown in FIG. 9, in this modification, the cavity bottom 21 has a trapezoidal shape in a cross section obtained by cutting the mold body 2 along a plane passing through the center of the cavity bottom 21 and extending in the axial direction. Come to

  Also in this modification, the height H 'of the center of the cavity bottom 21 from the outer end 25 of the cavity bottom 21 is 30% of the depth D of the cavity 20 at the position of the outer end 25 of the cavity bottom 21. Is also set to a large height. Further, the diameter W of the portion 27 near the center is set to be equal to or smaller than the outer diameter of the leg portion 52 of the SPR 50.

  Even if the shape of the bottom surface 21 of the cavity is as described above, the SPR 50 is driven into the plurality of members to be joined 60 toward the mold 1 and the leg corresponding portion of the member to be joined on the mold 61 When 61 a abuts on the cavity bottom surface 21, deformation of the leg corresponding portion 61 a is allowed between the mold side joined member 61 and the radially outer portion of the inclined surface 28 of the cavity bottom 21. It is possible to form such a gap. Thereby, when joining a plurality of to-be-joined members 60 comrades by SPR50, it can suppress that a crack arises in the mold side to-be-joined member 61. As shown in FIG.

  In the above modification, the bottom surface 21 of the cavity has a shape in which the tip of the conical surface is spherical, specifically, the near-center portion 27 has a spherical shape with the center 24 of the bottom surface 21 of the cavity 21 at the top. Alternatively, the inclined surface portion 28 may have a shape having an inclined plane as described above. The cavity bottom 21 has a spherical shape with the center 24 of the cavity bottom 21 at the top, such that the vicinity of the top is notched on a plane, specifically, the center vicinity 27 is not limited to the above. It may be a flat surface extending in a direction orthogonal to the axial direction, and may be a shape formed by an inclined curved surface such that the inclined surface portion 28 forms a part of a spherical shape.

  The present invention is not limited to the above embodiment, and can be substituted without departing from the scope of the claims.

  For example, in the above embodiment, the case where two members to be joined 60 are joined has been described, but the invention is not limited thereto, and the riveting mold of the present invention may be applied to the case where three or more members to be joined 60 are joined. 1 can be used.

  Moreover, in the said embodiment, although the metal mold | die main body part 2 comprised the column shape, it may be prismatic shape, if it can form not only this but the circular cavity 20 seeing from the said axial direction.

  The embodiments described above are merely illustrative and should not be construed as limiting the scope of the present invention. The scope of the present invention is defined by the claims, and all variations and modifications that fall within the equivalent scope of the claims fall within the scope of the present invention.

  The present invention is useful as a riveting mold for joining a plurality of members to be joined together by a self-piercing rivet.

1 riveting mold 2 mold body 10 upper surface (abutment surface)
20 cavity 21 cavity bottom 24 center of cavity bottom 25 outer end (radially outer end of cavity bottom)
26, 28 inclined surface 27 near center portion 30 cavity side surface 50 self-piercing rivet 60 bonded member 61 mold side bonded member D cavity depth at the deepest position of the cavity H, H 'cavity from the deepest position of the cavity Bottom center height

Claims (4)

When the plurality of members to be joined are joined together by a self-piercing rivet having a substantially cylindrical leg portion in a state in which the plurality of members to be joined are overlapped, the self-piercing rivet in the plurality of members to be joined is A riveting mold disposed on the side opposite to the self-piercing rivet in the portion to be driven, which is a riveting mold,
It has a columnar mold main body portion in which an end face on one side in the axial direction is in contact with the mold side joint member which is the joint member closest to the mold;
The mold main body portion bulges the other side of the axial direction of the mold side joining member by driving the self-piercing rivet in a portion excluding the outer peripheral edge portion of the end face on the one side in the axial direction. In order to allow deformation, it has a cavity which is recessed from the end face toward the other side in the axial direction and has a circular shape as viewed from the axial direction;
The cavity is constituted by a cavity bottom which is circular as viewed from the axial direction, and a cavity side,
The bottom surface of the cavity has a shape projecting toward the one side in the axial direction such that the center of the bottom surface of the cavity or a portion near the center including the center is located on the one side in the axial direction most Yes,
In a cross section obtained by cutting the mold body in a plane passing through the center of the bottom of the cavity and extending in the axial direction, an outer end which is a radial outer end of the bottom of the cavity, a center of the bottom of the cavity or The rivet is characterized in that the portion near the center is connected by an inclined surface portion inclined to the one side in the axial direction toward the center of the bottom surface of the cavity or the portion near the center from the outer end portion. Bonding mold. In the rivet joint mold according to claim 1,
The height of the center of the bottom of the cavity from the deepest position of the cavity is set to a height greater than 30% with respect to the depth of the cavity at the deepest position of the cavity. Mold for riveting. In the rivet joint mold according to claim 1 or 2,
The bottom surface of the cavity has a spherical shape such that the center of the bottom surface of the cavity is at the top,
The riveting mold according to claim 1, wherein the inclined surface portion of the bottom surface of the cavity is an inclined curved surface connecting the outer end portion and the top portion. In the rivet joint mold according to any one of claims 1 to 3,
The mold for riveting, wherein the side surface of the cavity is inclined outward in the radial direction from the outer end of the bottom surface of the cavity toward the one side in the axial direction.

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