JP2018176236A - 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, while maintaining bonding strength of the plural members to be joined together, in joining together the plural members to be joined with a self-pierce rivet.SOLUTION: On a cavity bottom surface 21 constituting a cavity 20 disposed on one side in an axial direction of a mold body part 2, a protrusion 40 is formed that protrudes toward the one side in the axial direction. A cavity bottom surface 21 of the cavity 20 comprises: a central bottom surface part 22 positioned more to the inside in a radial direction of the cavity bottom surface 21 than the protrusion 40; and an outer bottom surface part 23 positioned more to the outside in the radial direction than the protrusion 40. A depth D1 of the cavity 20 at a position of the central bottom surface part 22 is deeper than a depth D2 of the cavity 20 at a position of the outer bottom surface part 23.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.

  Further, in the rivet joint mold as disclosed in Patent Document 1, the annular raised portion suppresses the outflow of the mold side joining member at the time of driving the self-piercing rivet, so the leg portion of the self-piercing rivet is deformed. It becomes difficult and there exists a possibility that the joint strength of to-be-joined members may fall.

  This invention is made in view of such a point, and the place made into the objective maintains the joint strength of to-be-joined members appropriately, when joining several to-be-joined members by a self-piercing rivet. And restricting as much as possible the deformation of the die-side joined member which is the closest member to the rivet-joining die among the plurality of joined members, the die-side joined member It is an object of the present invention to provide a riveting mold capable of suppressing the formation of cracks in the

  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 cavity as viewed in the axial direction, and the cavity is constituted by a cavity bottom which is circular as viewed in the axial direction, and a side surface of the cavity having a flat portion, and the cavity bottom is A protrusion having an average diameter of the inner diameter and the outer diameter of the leg portion of the self-piercing rivet and formed on the one side in the axial direction is formed on a virtual circle concentric with the bottom surface of the cavity The portion is provided so as to extend continuously on the virtual circle, or a plurality of portions are provided intermittently on the virtual circle, and the protrusion when the number of the protrusion is one The protruding end surface of each of the protruding portions and the protruding end surface of each protruding portion in the case where there are a plurality of the protruding portions is a flat surface extending in the direction substantially orthogonal to the axial direction and having a predetermined width in the radial direction , In the above radial direction The central bottom portion located inside the projecting portion and the outer bottom portion located outside the projecting portion in the radial direction, and the depth of the cavity at the position of the central bottom portion is It is configured to be deeper than the depth of the cavity at the position of the outer bottom surface portion.

  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.

  In addition, since a protrusion is provided on a virtual circle having an average diameter of the inner diameter and the outer diameter of the leg portion of the self-piercing rivet on the bottom of the cavity, the mold side is joined The leg corresponding portion of the member abuts on the projecting end surface of the projecting portion of the bottom of the cavity. On the other hand, when the leg corresponding portion starts to abut on the projecting tip end surface, the inner deformation portion and the outer deformation portion of the mold side joined member are not yet in contact with the bottom and side surfaces of the cavity Become. That is, a gap is formed between the mold-side workpiece and the central bottom surface portion, the outer bottom surface portion, and the cavity side surface.

  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 workpiece extends and deforms inward and outward in the radial direction. This is because deformation of the leg corresponding portion is allowed by the gap. The inner deformation portion of the die-side joined member moves toward the central bottom surface portion along with the extension deformation of the leg portion corresponding portion. The outer deformation portion of the die-side joined member is bent and deformed toward the other side in the axial direction toward the outer bottom surface portion and the side surface of the cavity along with the extension deformation of the leg portion corresponding portion.

  Then, when the self-piercing rivet is further driven toward the riveting mold from the above state, the leg portion of the self-piercing rivet penetrates the members to be joined other than the mold-side workpiece. 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. . Thereby, joining of several to-be-joined members by a self-piercing rivet is completed. At this time, the outer deformation portion of the die-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. The leg portion corresponding portion of the mold side joined member is pushed by the leg portion and moves inward in the radial direction. Further, when the leg portion corresponding portion moves inward in the radial direction, the inner deformation portion of the die-side joined member further moves toward the central bottom surface portion.

  Therefore, in the rivet joint mold of the present invention, by providing the cavity with the projection of the appropriate size and shape in the cavity, the leg corresponding part of the die-side joined member abuts on the projection tip end face of the projection At the same time, a gap is formed between the mold-side workpiece and the central bottom surface portion, the outer bottom surface portion, and the side surface of the cavity to allow deformation of the leg portion 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.

  Further, when the depth of the cavity at the position of the central bottom surface portion is deeper than the depth of the cavity at the position of the outer bottom surface portion, when the leg corresponding portion of the mold side workpiece contacts the projecting tip surface The largest possible gap can be formed between the mold-side workpiece and the central bottom surface. As a result, when the self-piercing rivet is punched into a plurality of members to be joined, the leg portion corresponding portion of the die-side member to be joined is easily deformed. Further, when the leg portion of the self-piercing rivet is deformed so as to expand in diameter, the leg portion corresponding portion of the die-side joined member is easily moved inward in the radial direction. As a result, it is possible to more effectively suppress the occurrence of cracks in the mold side workpieces.

  Furthermore, when the leg portion of the self-piercing rivet is deformed so as to expand in diameter, the leg corresponding portion of the die-side joined member is easily moved inward in the radial direction, so the leg of the self-piercing rivet The part can be deformed properly. As a result, the joint strength of the plurality of members to be joined can be properly maintained by the self-piercing rivet.

  In the rivet bonding mold, the predetermined width in the radial direction of the protruding end surface is a cross section obtained by cutting the mold main body in a plane passing through the center of the bottom of the cavity and extending in the axial direction. The two straight lines respectively extending toward the one side in the axial direction along the flat portions of the side surfaces of the two cavities located on both sides in the radial direction, and the one axial direction in the axial direction of the mold main body 10% or more of the diameter at the open end of the cavity, defined by the length between two points of intersection with the radially extending straight line along the side end face Is desirable.

  That is, when the predetermined width of the projecting end surface is too narrow, the leg corresponding portion of the die-side joined member abuts on the projecting end surface, and then the leg corresponding portion is inward and outward in the radial direction. It becomes difficult to stretch and deform towards. In addition, there is a possibility that the protrusion bites into the mold-side workpiece to cause cracking of the mold-side workpiece. Therefore, when the self-piercing rivet is driven into a plurality of members to be joined by setting the predetermined width to a length of 10% or more with respect to the diameter at the open end of the cavity defined as above. The leg corresponding portion of the mold side joined member can be properly deformed. As a result, it is possible to more appropriately suppress the occurrence of cracks in the mold side workpieces.

  In the riveting mold, the height of the protrusion from the central bottom surface portion is set to a height greater than 30% with respect to the depth of the cavity at the position of the central bottom surface portion. Is desirable.

  That is, when the height of the protruding portion from the central bottom surface portion is too low, when the leg corresponding portion of the mold side bonded member abuts on the protruding portion, the mold side bonded member, the central bottom surface portion, the outside A gap allowing deformation of the leg corresponding portion of the die-side joined member is not sufficiently formed between the bottom portion and the cavity side surface. For this reason, the self-piercing rivets are formed into a plurality of members to be joined by setting the height of the protrusion from the central bottom to a value larger than 30% with respect to the depth of the cavity at the position of the central bottom. The gap is sufficiently formed when the leg corresponding portion abuts against the projection by driving. As a result, the leg corresponding portion can be appropriately deformed, so that generation of a crack in the mold-side joined member can be effectively suppressed.

  In the riveting mold, the outer bottom surface portion has a curved portion curved so that the intermediate portion in the radial direction is positioned on the other side in the axial direction than the end portions on both sides in the radial direction. It is desirable that it is formed.

  This makes it possible to form as large a gap as possible between the die-side joined member and the outer bottom surface portion when the leg corresponding portion of the die-side joined member abuts on the projecting end surface. . As a result, when the self-piercing rivet is punched into a plurality of members to be joined, the leg portion corresponding portion of the die-side member to be joined is easily deformed. In addition, 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 extended and deformed. As a result, it is possible to more appropriately suppress the occurrence of cracks in the mold side workpieces.

  In one embodiment of the riveting mold, the protrusion has an annular shape extending continuously in the entire circumferential direction of the imaginary circle.

  Further, in another embodiment of the rivet bonding mold, the plurality of protruding portions are intermittently formed on the virtual circle, and the plurality of protruding portions are equally spaced in the circumferential direction of the virtual circle. Lined up.

  According to this configuration, substantially the entire leg portion corresponding portion of the mold side member to be joined is brought into contact with the projecting end surface, and a gap that allows deformation of the leg portion corresponding portion of the mold side member to be joined is appropriately formed. can do. As a result, it is possible to more effectively suppress the occurrence of cracks in the mold side workpieces.

  In particular, in the case where a plurality of projecting portions are intermittently formed on the imaginary circle, the leg portions of the mold-side joined member also correspond to between adjacent projecting portions in the circumferential direction of the imaginary circle. Since the clearance for allowing the deformation of the part is formed, it is possible to more effectively suppress the occurrence of the crack in the mold side bonded member.

  In the riveting mold, the diameter of the bottom surface of the cavity is set to a length smaller than the diameter at the open end of the cavity, and the side surface of the cavity is the diameter toward the one side in the axial direction. Desirably, the flat portion of the side surface of the cavity is an inclined flat portion, which is inclined outward in the 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 face of one side of the mold main body in the axial direction has a columnar mold main body. A protrusion having an average diameter of the inner diameter and the outer diameter of the leg portion of the self-piercing rivet and formed on a virtual circle concentric with the bottom surface of the cavity, and having a protruding portion projecting to the one side in the axial direction Therefore, when the plurality of members to be joined are joined together by the self-piercing rivet, the deformation of the die-side members to be restrained is suppressed as much as possible, and the crack is generated in the die-side member Can be suppressed.

  In addition, the cavity bottom surface has a central bottom surface portion positioned inside the protrusion in the radial direction, and an outer bottom surface portion positioned outside the protrusion in the radial direction, and the center bottom surface Since the depth of the cavity at the location of the part is deeper than the depth of the cavity at the location of the outer bottom part, the leg of the self-piercing rivet can be appropriately deformed so as to expand in diameter. As a result, the joint strength of the plurality of members to be joined can be properly maintained by the self-piercing rivet.

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. 2 equivalent view of the metal mold | die for rivet connection which concerns on Embodiment 2 of this invention. FIG. 10 is an enlarged cross-sectional view enlarging a portion around a cavity in a die main body section cut by XX in FIG. 9; FIG. 10 is an enlarged cross-sectional view enlarging a portion around a cavity in a mold body section cut along line XI-XI in FIG. 9;

  Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

(Embodiment 1)
FIG. 1 shows a rivet bonding mold 1 (hereinafter simply referred to as a mold 1) according to a first 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, in a region where the peripheral portion of the upper surface 10 remains. 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 so as to be coaxial with the mold body 2 (that is, the center of the cavity bottom 21 described later is located on the axis of 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. That is, the cavity 20 is a cavity which allows the bulging deformation to the lower side (that is, the other side in the axial direction) of the portion where the SPRs 50 in the plurality of members 60 to be welded are driven.

  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 SPR 50 is driven is restrained by the die 1, and the die-side joined members Cracking may occur at 61. 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 first 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 Di2 of the cavity bottom 21 is set to a value smaller than Di1 at the open end of the cavity 20. The diameter Di2 of the cavity bottom 21 is, as shown in FIG. 3, the diameter at the radially outer end of the outside bottom 23 described later of the cavity bottom 21. The definition of the diameter Di1 at the open end of the cavity 20 will be described later.

  Also, as shown in FIGS. 2 and 3, the cavity bottom 21 has an average diameter of the inner diameter and the outer diameter of the leg 52 of the SPR 50 and is a cavity on an imaginary circle C concentric with the cavity bottom 21. A protrusion 40 is formed to protrude upward from the bottom surface 21.

  As shown in FIG. 2, the protrusion 40 has an annular shape that is continuous in the entire circumferential direction of the imaginary circle C. As a result, the cavity bottom surface 21 is located on the inner side in the radial direction with respect to the projecting portion 40 by the projecting portion 40, and the central bottom surface portion 22 circularly viewed from the axial direction and the diameter than the projecting portion 40 It is bisected into an outer bottom surface portion 23 located outside in the direction and having a substantially annular shape when viewed from the axial direction.

  As shown in FIGS. 2 and 3, the central bottom surface portion 22 is formed of a flat surface extending in a direction (that is, a horizontal direction) orthogonal to the axial direction. On the other hand, the outer bottom surface portion 23 is formed by a curved portion which is curved so that the radial intermediate portion is located lower than both radial end portions in the entire circumferential direction. As a result, the curved portion is formed outside the radial direction with respect to the projection 40 and in a portion between the radial projection 40 and the cavity side surface 30.

  Further, as shown in FIG. 3, the depth D1 of the cavity 20 at the position of the central bottom portion 22 is deeper than the depth D2 of the cavity 20 at the deepest position of the outer bottom portion 23.

  As shown in FIG. 3, the cavity side surface 30 obliquely extends outward in the radial direction from the radial outer end of the cavity bottom surface 21 (strictly speaking, the outer bottom surface portion 23) toward the upper side. . 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 upper side surface The lower side surface portion 32 is an inclined plane extending in an inclined manner outward in the radial direction toward the upper side so as to connect the lower end of the portion 31 and the outer end of the outer bottom surface portion 23 with the radial direction. Have. In the first embodiment, the lower side surface portion corresponds to a flat portion.

  The projecting portion 40 is a flat surface having a projecting distal end surface 41 extending in a direction orthogonal to the axial direction and having a predetermined width W in the radial direction. Thereby, as shown in FIG. 3, the protrusion 40 has a trapezoidal shape in a cross section cut along the radial direction of the mold main body 2. In the projecting portion 40, a portion on the inner side in the radial direction with respect to the projecting front end surface 41 is an inner inclined portion 42 inclined downward toward the inner side in the radial direction. An outer portion in the direction is an outer inclined portion 43 which is inclined downward toward the outer side in the radial direction.

  As shown in FIG. 3, the inner inclined portion 42 is an upper inclined curved surface portion 42 a having an inclined curved surface continuous with the projecting end surface 41 and a lower side having an inclined curved surface continuous with the central bottom surface portion 22. The inclined curved surface portion 42b and the inclined flat surface portion 42c that is linearly inclined so as to connect the lower end of the upper inclined curved surface portion 42a and the upper end of the lower inclined curved surface portion 42b are provided.

  On the other hand, the outer inclined portion 43 also has, similarly to the inner inclined portion 42, an upper inclined curved surface portion 43a having an inclined curved surface continuous with the projecting end surface 41 and an inclined curved surface continuous to the central bottom surface portion 22. It extends linearly in the axial direction so as to connect the lower inclined curved surface portion 43b and the lower end of the upper inclined curved surface portion 43a and the upper end of the lower inclined curved surface portion 43b, and the radial direction toward the upper side And an inclined flat portion 43c that extends in an inclined manner.

  In the first embodiment, the predetermined width W in the radial direction of the protruding end surface 41 is set to a length of 10% or more with respect to the diameter Di1 at the opening end of the cavity 20.

  Specifically, as shown in FIG. 3, the diameter Di1 at the open end of the cavity 20 is a radial direction 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. The length between each intersection point P of two straight lines L1 extending upward along the lower side surface portion 32 of the cavity side surface 30 positioned on both sides of the cavity and the radial extension straight line L2 along the upper surface 10 Defined by The predetermined width W of the projecting end surface 41 is set to 10% or more of the diameter Di1 at the opening end of the cavity 20 defined as described above.

  The diameter Di1 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 portion 52 of the SPR 50 is suitable so as to easily penetrate through members to be joined other than the die-side member to be joined 61 among the plurality of members to be joined 60 and to easily deform in diameter. It is set to a value.

  In the first embodiment, the height H of the protrusion 40 from the central bottom surface 22 is set to a value larger than 30% with respect to the depth D1 of the cavity 20 at the position of the central bottom surface 22. .

  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 protrusion 40 of the mold 1 comes to be 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. Also, in the die-side joined member 61, the radially inner portion of the leg portion 52 (hereinafter referred to as the inner deformation portion 61c) is also the outer portion in the radial direction, similar to the leg portion corresponding portion 61a. It is stretched and deformed. 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.

  Further, as shown in FIG. 6, the leg corresponding portion 61 a of the mold side joined member 61 abuts on the projecting end surface 41 of the projecting portion 40 of the cavity bottom face 21, while the outer side of the mold side joined member 61. The deformation portion 61 b and the inner deformation portion 61 c do not abut on the cavity bottom surface 21 and the cavity side surface 30. That is, a gap is formed between the mold-side joined member 61, the central bottom surface portion 22, the outer bottom surface portion 23, and the cavity side surface 30.

  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 leg portion corresponding portion 61 a of the mold-side joined member 61 stretches and deforms inward and outward in the radial direction. This is because deformation of the leg corresponding portion 61a is permitted by the gap. The inner deformation portion 61c of the mold side bonded member 61 moves so as to be pushed out toward the central bottom surface portion 22 in accordance with the elongation deformation of the leg portion corresponding portion 61a. Further, the outer deformation portion 61b of the die-side joined member 61 is bent downward toward the outer bottom surface portion 23 and the cavity side surface 30 with the extension deformation of the leg portion corresponding portion 61a.

  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 outer deformation portion 61b of the mold-side joined member 61 is further bent and deformed toward the lower side, and slightly pushed outward in the radial direction by the biting of the leg portion 52. The leg corresponding portion 61a of the mold side joined member 61 is pushed by the leg 52 and moves inward in the radial direction. Further, the inner deformation portion 61c of the die-side joined member 61 further moves toward the central bottom surface portion 22 with the movement of the leg portion corresponding portion 61a and abuts on the central bottom surface portion 22. 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 portion corresponding portion 61 a of the mold side joined member 61 abuts on the projecting end surface 41, the above-mentioned radial direction inside and outside of the projecting portion 40 is more than the above. A gap is formed 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.

  Further, since the depth D1 of the cavity 20 at the position of the central bottom surface portion 22 is deeper than the depth D2 of the cavity 20 at the position of the outer bottom surface portion 23, the leg portion 52 of the SPR 50 is deformed to expand in diameter. At the same time, the die-side joined member 61 is more easily moved inward in the radial direction than the protrusion 40. Thereby, since the leg part 52 of SPR50 is deform | transformed appropriately, the joint strength of some to-be-joined member 60 comrades can be maintained appropriately. Incidentally, the depth D1 of the cavity 20 at the position of the central bottom surface portion 22 is such that the inner deformation portion 61c of the mold side workpiece 61 is the central bottom surface portion in a state in which bonding of the plurality of workpieces 60 by SPR 50 is completed The depth is set to abut on the surface 22.

  Here, if the predetermined width W of the projecting end surface 41 in the radial direction of the cavity bottom 21 is too narrow, the leg corresponding portion 61 a of the die-side joined member 61 abuts on the projecting end surface 41, It becomes difficult to extend and deform toward the inner side and the outer side in the radial direction. In addition, the protrusion 40 may bite into the mold-side workpiece 61 and cause cracking of the mold-side workpiece 61. Therefore, in the present embodiment, the predetermined width W of the protruding tip surface 41 in the radial direction is relative to the diameter Di1 at the opening end of the cavity 20, that is, it passes through the center of the cavity bottom 21 and in the axial direction. In a cross section obtained by cutting the mold main body 2 with an extending plane, the two straight lines L1 extending upward along the inclined flat surface portion 33 of the cavity side surface 30 located on both sides in the radial direction and the above The length is set to 10% or more with respect to the length between two points of intersection P with the radially extending straight line L2.

  In addition, when the height H of the protrusion 40 from the central bottom surface 22 is too low, when the leg corresponding portion 61 a of the die-side joined member 61 abuts on the protrusion tip surface 41, The clearance which allows the deformation of the leg corresponding portion 61a is not sufficiently formed on the inner side and the outer side in the radial direction. Therefore, in the first embodiment, the height H of the projecting portion 40 from the central bottom surface portion 22 is set to a value larger than 30% with respect to the depth D1 of the cavity 20 at the position of the central bottom surface portion 22. .

  Further, in the first embodiment, since the inner and outer inclined portions 42 and 43 have the upper inclined curved surface portions 42 a and 43 a which are continuous with the protruding tip end surface 41, cracks are generated in the mold side joined member 61. Can be suppressed more appropriately. That is, assuming that edges are formed at respective corners between the inner and outer inclined portions 42 and 43 and the projecting end surface 41, the mold side joined member 61 abuts on the projecting end surface 41. After that, when the SPR 50 is further driven toward the mold 1, the edge bites into the mold-side joined member 61, and there is a possibility that a crack may occur from the bite of the edge. As in the first embodiment, in the inner and outer inclined portions 42 and 43, the upper inclined curved portion 42a. If 43 a is formed, the edge does not bite into the die-side joined member 61, and thus the occurrence of cracks in the die-side joined member 61 is more appropriately suppressed.

  Furthermore, in the first embodiment, the cavity side surface 30 is inclined outward in the radial direction from the radially outer end of the cavity bottom surface 21 (strictly, the outer bottom surface portion 23) to the upper side, When 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, the deformation of the outer deformation portion 61b of the mold-side joined member 61 becomes gold. It is difficult to be restrained by the mold 1 and the outer deformation 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, in the first embodiment, the cylindrical mold main body 2 is provided such that the end surface (upper surface 10) on one side (upper side) in the axial direction is in contact with the mold bonding member 61. The mold main body portion 2 is a portion from the end face in order to allow the deformation of the mold side joined member 61 to the one side in the axial direction 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 recessed toward the other side in the axial direction and has a circular shape as viewed from the axial direction, and the cavity 20 has a cavity bottom surface 21 having a circular shape as viewed from the axial direction; Formed on a virtual circle C having an average diameter of the inner diameter and the outer diameter of the leg portion 52 of the SPR 50 in the cavity side surface 30 having the inclined plane portion 33) and the cavity bottom surface 21; Protruding to one side of the axial direction The projecting portion 40 has an annular shape continuously extending in the entire circumferential direction on the imaginary circle C, and the projecting tip end surface 41 of the projecting portion 40 has the above-mentioned axial direction The cavity bottom surface 21 is located inside the radial direction with respect to the projecting portion 40 and has a circular shape when viewed from the axial direction. Of the central bottom surface portion 22 and the outer bottom surface portion 23 positioned outside the radial direction with respect to the projecting portion 40 and having a substantially annular shape when viewed from the axial direction; Since the depth D1 of the cavity 20 at the position is deeper than the depth D2 of the cavity 20 at the position of the outer bottom surface portion 23, the mold side joined member 61 is used when joining a plurality of joined members 60 together by SPR 50. Can be constrained in Of the mold side joined member 61 can be suppressed, and the leg portion 52 of the SPR 50 can be appropriately deformed to expand in diameter, and a plurality of joined members The bonding strength between the two can be maintained properly.

Second Embodiment
9 to 11 show a rivet bonding mold 101 (hereinafter referred to as a mold 101) according to the second embodiment. The same reference numerals as in the first embodiment denote the same parts in FIGS. 9 to 11. In the following description, detailed description of the parts common to the first embodiment is omitted.

  In the second embodiment, the shapes of the bottom surface 121 of the cavity 120 and the protrusion 140 are different from the first embodiment.

  Specifically, in the second embodiment, as shown in FIG. 9, a plurality of (six in the second embodiment) the protrusion 140 is intermittently provided in the circumferential direction around the center of the cavity bottom surface 121. . More specifically, the plurality of protrusions 140 are formed intermittently on the imaginary circle C.

  Further, in the second embodiment, as shown in FIGS. 10 and 11, the outer bottom surface portion 123 of the cavity bottom surface 121 is not curved downward but is flat. On the other hand, the central bottom surface portion 122 of the cavity bottom surface 121 is flat as in the first embodiment. Further, in the cavity bottom surface 121, a portion located between the adjacent protruding portions 140 in the circumferential direction around the center of the cavity bottom surface 121 is a flat surface continuous with the outer bottom surface portion 123 as shown in FIG. ing.

  Even in the configuration of the second embodiment, the SPR 50 is driven into the plurality of members to be joined 60 toward the mold 1, and the leg corresponding portion 61a of the member to be joined 61 of the mold When it abuts, deformation of the leg corresponding portion 61a of the mold-side joined member 61 is allowed between the mold-side joined member 61, the central bottom surface portion 122, the outer bottom surface portion 123, and the cavity side surface 30. Since the gap is formed, the same effect as that of the first embodiment can be obtained.

  Further, in the configuration of the second embodiment, a gap that allows deformation of the leg corresponding portion 61a of the mold side joined member 61 also in the region between the adjacent protruding portions 140 in the circumferential direction of the virtual circle C. Can be formed, so that generation of cracks in the mold-side joined member 61 can be further effectively suppressed.

  In FIG. 9, the plurality of protruding portions 140 are arranged at equal intervals in the circumferential direction of the virtual circle C, but the protruding portions 140 do not necessarily have to be arranged at equal intervals in the circumferential direction. However, from the viewpoint of uniformly deforming the leg corresponding portion 61a, the outer deformation portion 61b, and the inner deformation portion 61c of the mold-side workpiece 61, the protrusions 140 are arranged at equal intervals in the circumferential direction. It is desirable to In addition, the number of the protruding portions 140 may be five or less, or seven or more, as long as it can prevent the occurrence of cracks in the mold side welded member 61.

(Other embodiments)
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 (101) can be used.

  Further, in the above embodiment, the projecting portion 40 (140) is annular as viewed from the axial direction of the mold 1 (101), but the present invention is not limited to this, a part of the annular ring is broken It may be C-shaped.

  Furthermore, in the above embodiment, the mold body 2 has a cylindrical shape, but the present invention is not limited to this, and it may be prismatic if it can form a circular cavity 20 (120) when viewed from the axial direction It is also good.

  Further, in the above embodiment, the protruding end surface 41 is a flat surface extending in the direction orthogonal to the axial direction of the mold main body portion 2. However, the present invention is not limited thereto. It may be slightly inclined upward toward the inner side or the outer side of the radial direction as long as it can be prevented from occurring.

  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 plate-like members to be joined together by a self-piercing rivet.

1,101 riveting mold 2,102 upper surface of mold body 10 (end face of one side of mold body in the axial direction)
20, 120 Cavities 21, 121 Cavity Bottom 22, 122 Center Bottom 23, 23 Outer Bottom 30 Cavity Side 32 Lower Side (Plane of Cavity Side)
40, 140 Protrusions 41 Protrusive tip surface 50 Self-piercing rivets 52 Legs 60 Bonded members 61 Mold side bonded members C Virtual circle D1 Depth at the center bottom of the cavity D2 Depth Di1 at the outside bottom of the cavity The diameter Di2 at the open end of the hole The diameter H of the bottom of the cavity The height of the protrusion with respect to the central bottom of the protrusion W The radial length of the protruding end surface

Claims (7)

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 having a flat portion,
A protrusion having an average diameter of the inner diameter and the outer diameter of the leg portion of the self-piercing rivet on the bottom of the cavity, and a protrusion projecting to the one side in the axial direction on a virtual circle concentric with the bottom of the cavity Is formed,
One protrusion is provided so as to extend continuously on the virtual circle, or a plurality of protrusions are intermittently provided on the virtual circle,
The protrusion tip end surface of the protrusion when the number of the protrusion is one and the protrusion tip end surface of each protrusion when the protrusion is plural extend in the direction substantially orthogonal to the axial direction and in the radial direction It is a plane with a predetermined width,
The cavity bottom surface has a central bottom surface portion located inside the protrusion in the radial direction and an outer bottom surface portion located outside the protrusion in the radial direction,
A riveting mold characterized in that the depth of the cavity at the position of the central bottom portion is deeper than the depth of the cavity at the position of the outer bottom portion. In the rivet joint mold according to claim 1,
The predetermined width in the radial direction of the projecting end surface is located on both sides in the radial direction in a cross section obtained by cutting the mold main body in a plane passing through the center of the bottom of the cavity and extending in the axial direction The two straight lines respectively extending toward the one side in the axial direction along the flat portions of the side surfaces of the cavity and the diameter along the end surface of the one side in the axial direction of the mold main body Set for 10% or more of the diameter at the open end of the cavity, defined by the length between two points of intersection with a straight line extending in the direction, Mold. In the rivet joint mold according to claim 1 or 2,
The height of the protruding portion from the central bottom surface portion is set to a height greater than 30% with respect to the depth of the cavity at the position of the central bottom surface portion. Mold. In the rivet joint mold according to any one of claims 1 to 3,
The outer bottom surface portion is characterized in that a curved portion curved so that the middle portion in the radial direction is positioned on the other side in the axial direction than the end portions on both sides in the radial direction. Riveting molds. In the rivet joint mold according to any one of claims 1 to 4,
The riveting mold according to claim 1, wherein the projection has an annular shape extending continuously in the entire circumferential direction of the imaginary circle. In the rivet joint mold according to any one of claims 1 to 4,
The plurality of projecting portions are intermittently formed on the virtual circle,
The riveting mold according to claim 1, wherein the plurality of projecting portions are arranged at equal intervals in the circumferential direction of the imaginary circle. In the rivet joint mold according to any one of claims 1 to 6,
The diameter of the bottom of the cavity is set to a length smaller than the diameter at the open end of the cavity,
The cavity side surface is inclined outward in the radial direction toward the one side in the axial direction,
The mold for riveting, wherein the flat portion on the side surface of the cavity is an inclined flat portion.

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