JP2018176234A - 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: 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 protrusion apical surface 41 of the protrusion 40 is a plane surface that extends in a substantially orthogonal direction to the axial direction and has a predetermined width W in a radial direction. The predetermined width W of the protrusion apical surface 41 is set to have a length of 10% or more relative to a diameter Di1 at an opening end of the cavity 20, whereas a height H of the protrusion 40 from a deepest position of the cavity 20 is set to have a greater value than 30% relative to the depth D of the cavity 20 at the deepest position.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a rivet joining mold used when joining a plurality of members to be joined by self-piercing rivets.

  Conventionally, a self-piercing rivet is sometimes used to join a plurality of members to be joined, and a rivet joining mold is used for joining with the self-piercing rivet.

  In the rivet joining mold described in Patent Document 1, when joining by a self-piercing rivet, a base main body that comes into contact with a mold-side joined member that is a joined member closest to the mold among a plurality of joined members The base body is formed with a recess (cavity) that allows the mold-side bonded member to bulge and deform when the self-piercing rivet is driven, and an annular bulge is formed in the central region of the bottom surface of the recess. Is provided.

  Further, in the rivet joining mold described in Patent Document 1, when the self-piercing rivet is driven, the mold side joined member is moved from the radially inner side to the radially outer side than the raised portion. Outflow is suppressed by the raised portion.

JP-T-2015-529562

  By the way, when joining a plurality of members to be joined by self-piercing rivets, in the portion where the self-piercing rivet is driven in the plurality of members to be joined, the self-piercing rivet is opposite to the driving side. The rivet joining mold is arranged, and the self-piercing rivet is driven into a plurality of members to be joined toward the rivet joining mold.

  In general, a self-piercing rivet is driven into a rivet-bonding die, and a swelled member to be bonded closest to the rivet-bonding die among a plurality of members to be bonded (hereinafter referred to as a mold-side bonded member). Since the cavity recessed so as to allow the deformation is provided, when the self-piercing rivet is driven into the plurality of members to be bonded, the mold side bonded member bulges and deforms into the cavity. Then, the legs of the self-piercing rivet penetrate the member to be joined other than the mold side joined member, and the plurality of members to be joined are joined by biting into the mold side joined member. Moreover, when the leg part of the self-piercing rivet bites into the mold side member to be joined, the leg part is deformed so as to expand its diameter, whereby the plurality of members to be joined are firmly joined.

  However, according to the study by the inventors of the present application, in order to join a plurality of members to be joined by self-piercing rivets, when the self-piercing rivets are driven into the plurality of members to be joined, It has been found that cracks may occur.

  Further, when the inventors of the present application have further studied, the cracks in the mold-side bonded member are portions corresponding to the legs of the self-piercing rivet in the mold-side bonded member (hereinafter referred to as leg corresponding portions). However, when trying to stretch and deform in the cavity toward the outside in the radial direction of the cavity, the elongation is caused by the rivet bonding mold, specifically, the portion constituting the cavity in the rivet bonding mold. This is because 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 mold side bonded member. I understood that.

  In patent document 1, the outflow of the mold side bonded member when the self-piercing rivet is driven is suppressed by the annular raised portion. However, in the rivet bonding mold of Patent Document 1, deformation of the leg corresponding portion of the mold side bonded member is constrained by the annular raised portion, and the mold side bonded member is formed from the annular raised portion. As a result of the repulsive load being input to the leg-corresponding portion, there is a risk that cracks will occur in the mold-side joined member.

  The present invention has been made in view of such points, and an object of the present invention is to provide a rivet bonding gold among a plurality of members to be bonded when bonding a plurality of members to be bonded by self-piercing rivets. For rivet bonding, which can suppress the deformation of the mold side bonded member that is the closest bonded member to the mold as much as possible, and can prevent the mold side bonded member from cracking. To provide molds.

  In order to solve the above-described problem, the present invention provides a method for joining a plurality of members to be joined by a self-piercing rivet having a substantially cylindrical leg in a state where the plurality of members to be joined are overlapped. In a portion where the self-piercing rivet is driven in a plurality of members to be joined, an end face on one side in the axial direction is intended for a rivet-joining mold disposed on the side opposite to the driving side of the self-piercing rivet. A columnar mold main body that is in contact with a mold-side bonded member that is the member to be bonded closest to the mold; and the mold main body is located outside the end surface on the one side in the axial direction. From the end face to the other side in the axial direction, in order to allow bulging deformation of the mold side joined member to the other side in the axial direction due to the driving of the self-piercing rivet in a portion excluding the peripheral portion. Indented, The cavity has a circular shape when viewed from the axial direction, and the cavity includes a circular cavity bottom surface when viewed from the axial direction and a cavity side surface having a flat portion. A projecting portion projecting to the one side in the axial direction is formed on a virtual circle having an average diameter of the inner diameter and the outer diameter of the legs of the self-piercing rivet and concentric with the bottom surface of the cavity. One part is provided so as to continuously extend on the virtual circle, or a plurality of parts are provided intermittently on the virtual circle, and the protrusion is provided when the number of the protrusions is one. In the case where there are a plurality of protruding tip surfaces and a plurality of protruding portions, the protruding tip surface of each protruding portion is a flat surface extending in a direction substantially orthogonal to the axial direction and having a predetermined width in the radial direction. The radial direction of the tip surface The predetermined width is along the plane portions of the two side surfaces of the cavity located on both sides in the radial direction in a cross section obtained by cutting the mold main body by a plane passing through the center of the cavity bottom surface and extending in the axial direction. And two intersections of two straight lines extending toward the one side in the axial direction and a straight line extending in the radial direction along the end surface on the one side in the axial direction of the mold main body. The height of the protrusion from the deepest position of the cavity is set to a length of 10% or more with respect to the diameter at the open end of the cavity defined by the length between The height is set to be higher than 30% with respect to the depth of the cavity at the deepest position.

  According to this configuration, when a plurality of members to be joined are joined by self-piercing rivets, it is possible to suppress the occurrence of cracks in the mold side joined members.

  Specifically, the mold main body portion is provided with a cavity that is recessed to allow bulging deformation to the other side in the axial direction of the mold-side bonded member. When the self-piercing rivet is driven into the plurality of members to be bonded toward the rivet bonding mold in the overlapped state, the plurality of members to be bonded bulge out into the cavity of the mold body. Transforms into At this time, a portion (hereinafter referred to as a leg portion corresponding portion) corresponding to the leg portion of the self-reliable rivet in the mold side bonded member is extended and deformed radially outward of the cavity bottom surface. Further, in the mold side bonded member, a portion on the inner side in the radial direction from the leg portion (hereinafter referred to as an inner deformed portion) is also extended and deformed outward in the radial direction in the same manner as the leg portion corresponding portion. The On the other hand, in the mold side bonded member, the radial direction is more outward than the leg part and the radial side than the boundary part between the cavity side surface and the one end face in the axial direction of the mold main body part. 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, the bottom of the cavity has an average diameter of the inner and outer diameters of the legs of the self-piercing rivet, and a protrusion is formed on a virtual circle concentric with the bottom of the cavity. The leg-corresponding portion of the member abuts on the protruding tip surface of the protruding portion on the bottom surface of the cavity. On the other hand, when the leg corresponding portion starts to contact the protruding tip surface, the inner deformed portion and the outer deformed portion of the mold side bonded member are not yet in contact with the cavity bottom surface and the cavity side surface. Become. That is, a gap is formed between the inner and outer portions in the radial direction and the side surface of the cavity with respect to the protrusion on the bottom surface of the cavity, and the mold side bonded member.

  When the self-piercing rivet is driven further into the rivet-joining mold from the above state, the mold-side joined member is further deformed so as to bulge into the cavity. At this time, the leg corresponding portion of the mold side bonded member is extended and deformed toward the inner side and the outer side in the radial direction. This is because the leg corresponding portion is allowed to be deformed by the gap. The inner deformed portion of the mold side bonded member moves toward the radially inner portion of the cavity bottom surface with respect to the projecting portion in accordance with the elongation deformation of the leg corresponding portion. The outer deformed portion of the die-side bonded member is moved in the axial direction toward the radially outer portion and the side surface of the cavity with respect to the projecting portion on the cavity bottom surface along with the elongation deformation of the leg corresponding portion. It is bent and deformed to the other side.

  When the self-piercing rivet is driven further into the rivet-bonding die from the above state, the leg portion of the self-piercing rivet penetrates the member to be joined other than the die-side member to be joined. Thereafter, when the self-piercing rivet is further driven, the legs of the self-piercing rivet bite into the die-side bonded member while deforming so as to expand from the rivet-bonding die to the outside in the radial direction due to the repulsive load. . Thereby, joining of several to-be-joined members by a self-piercing rivet is completed. At this time, the outer deformed portion of the mold side bonded 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-corresponding part of the mold-side joined member is pushed by the leg part and moves inward in the radial direction.

  Therefore, in the rivet bonding mold according to the present invention, a protrusion having an appropriate size and shape on the bottom surface of the cavity (that is, the predetermined width in the radial direction of the protrusion tip surface is 10% of the diameter at the opening end of the cavity. And the height of the protrusion from the deepest position of the cavity is higher than 30% with respect to the depth of the cavity at the deepest position of the cavity). When the leg-corresponding portion of the side bonded member is in contact with the protruding front end surface of the protruding portion, the radially inner and outer portions of the cavity bottom surface and the cavity side surface with respect to the protruding portion on the cavity bottom surface, the mold side bonded member A gap is formed so as to allow deformation of the leg corresponding portion. Thereby, when joining a plurality of members to be joined by self-piercing rivets, it is possible to suppress deformation of the mold side joined member as much as possible, and as a result, the mold side joined member. It is possible to suppress the occurrence of cracks.

  In the rivet bonding mold, the bottom surface of the cavity has a central bottom surface portion located inside the projecting portion in the radial direction and an outer bottom surface portion located outside the projecting portion in the radial direction. The outer bottom surface portion is formed with a curved portion that is curved and recessed so that the radial intermediate portion is located on the other side in the axial direction with respect to the ends on both sides in the radial direction. It is desirable that

  This makes it possible to form a gap as large as possible between the mold-side bonded member and the outer bottom surface when the leg-corresponding portion of the mold-side bonded member comes into contact with the protruding portion. Thereby, when the self-piercing rivet is driven into a plurality of members to be joined, the leg corresponding portions of the mold side members to be joined are easily deformed. Further, when the legs of the self-piercing rivet are deformed so as to expand in diameter, the outer deformed portion of the mold side joined member is easily stretched and deformed. As a result, it is possible to more appropriately suppress the occurrence of cracks in the mold side bonded member.

  In the rivet bonding mold in which the cavity bottom surface has a center bottom surface portion and an outer bottom surface portion, the depth of the cavity at the position of the center bottom surface portion is deeper than the depth of the cavity at the position of the outer bottom surface portion. Preferably, 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.

  As a result, a gap as large as possible can be formed between the mold-side joined member and the center bottom surface when the leg-corresponding portion of the mold-side joined member comes into contact with the protruding tip surface. it can. Thereby, when the self-piercing rivet is driven into a plurality of members to be joined, the leg corresponding portions of the mold side members to be joined are easily deformed. Further, when the legs of the self-piercing rivet are deformed so as to expand in diameter, the leg-corresponding portion of the mold-side joined member is easily moved toward the inside in the radial direction. As a result, it is possible to more effectively suppress the occurrence of cracks in the mold side bonded member. Moreover, since it becomes easy to deform | transform so that the leg part of a self-piercing rivet may expand, the joint strength of several to-be-joined members can be ensured appropriately.

  In one embodiment of the rivet bonding mold, the protruding portion has an annular shape extending continuously over the entire circumferential direction of the virtual circle.

  In another embodiment of the rivet bonding mold, the plurality of protrusions are intermittently formed on the virtual circle, and the plurality of protrusions are equally spaced in the circumferential direction of the virtual circle. Are lined up.

  According to this configuration, substantially the entire leg-corresponding part of the mold-side joined member is brought into contact with the protruding tip surface, and a gap that allows deformation of the leg-corresponding part of the mold-side joined member is appropriately formed. can do. Thereby, it can suppress more effectively that a crack arises in a metallic mold side joined member.

  In particular, when a plurality of protrusions are intermittently formed on the virtual circle, the mold-side bonded member legs also correspond to the protrusions adjacent to each other in the circumferential direction of the virtual circle. Since the clearance which accept | permits a deformation | transformation of a part is formed, it can suppress more effectively that a crack arises in a die side to-be-joined member.

  In the rivet bonding mold, the diameter of the bottom surface of the cavity is set to a length smaller than the diameter at the opening end of the cavity, and the side surface of the cavity has the diameter toward the one side in the axial direction. It is desirable that the flat portion of the cavity side surface is an inclined flat portion that is inclined outward in the direction.

  Accordingly, when the leg portion of the self-piercing rivet is deformed so as to expand in diameter, the outer deformed 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 deformation of the mold side bonded member, and it is possible to more effectively suppress the occurrence of cracks in the mold side bonded member.

  As described above, according to the rivet bonding mold according to the present invention, the cavity bottom surface is provided with a columnar mold body portion and constitutes a cavity formed on one end face in the axial direction of the mold body portion. Are formed on a virtual circle having an average diameter of the inner diameter and the outer diameter of the legs of the self-piercing rivet and concentric with the bottom of the cavity, and projecting to the one side in the axial direction. The protruding tip surface of the protruding portion is a flat surface extending in a direction substantially orthogonal to the axial direction and having a predetermined width in the radial direction, and the predetermined width in the radial direction of the protruding tip surface Is extended in the axial direction along the plane part of the cavity side surface located on both sides of the radial direction in a cross section obtained by cutting the mold main body part in a plane passing through the center of the cavity bottom surface and extending in the axial direction. 2 straight lines and above 10% or more with respect to the diameter at the open end of the cavity defined by the length between each intersection with the straight line extending in the radial direction along the one end face in the axial direction of the mold body The height of the protrusion from the deepest position of the cavity is set to a value greater than 30% with respect to the depth of the cavity at the deepest position of the cavity. When joining a plurality of members to be joined by the self-piercing rivet, the deformation of the mold side joined member is restrained as much as possible to prevent the mold side joined member from cracking. can do.

It is the perspective view which looked at the metal mold | die for rivet joining which concerns on Embodiment 1 of this invention from diagonally upper side. It is the top view which looked at the said metal mold for rivet joining from the upper side. It is the expanded sectional view which expanded the part of the cavity periphery in the metal mold | die main-body part cut | disconnected by the III-III line | wire of FIG. It is a side view of a self-piercing rivet. Sectional drawing which shows the state which has arrange | positioned the said rivet joining metal mold | die, the said self-piercing rivet, and the said two to-be-joined members in order to join two to-be-joined members by a self-piercing rivet using the said rivet joining metal mold | die. It is. FIG. 6 is a cross-sectional view showing a state where the self-piercing rivet is driven toward the rivet joining mold from the state of FIG. 5. FIG. 7 is a cross-sectional view showing a state where the self-piercing rivet is further driven toward the rivet joining mold from the state of FIG. 6. It is sectional drawing which shows the state which joining of the said 2 to-be-joined member by the said self-piercing rivet was completed. FIG. 6 is a view corresponding to FIG. 3 of a rivet joining mold according to a second embodiment of the present invention. It is FIG. 2 equivalent view of the metal mold | die for rivet joining which concerns on Embodiment 3 of this invention. FIG. 6 is a view corresponding to FIG. 3 showing a rivet joining mold according to a third embodiment of the present invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
FIG. 1 shows a rivet joining mold 1 (hereinafter simply referred to as a mold 1) according to Embodiment 1 of the present invention. This metal mold 1 is a metal mold used when a plurality of plate-like members to be joined 60 (see FIGS. 5 to 8) are joined together by a self-piercing rivet 50 (see FIG. 4, hereinafter referred to as SPR50). .

  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 corresponding to the size of the SPR 50 (see FIG. 4) used for bonding. In addition, since the mold 1 is arranged so that the mold body 2 is on the upper side and the mold shank 3 is on the lower side in the usage state, in the following description, in accordance with the usage state, the mold 1 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).

  As shown in FIGS. 5 to 8, the upper surface 10 that is the upper end surface (that is, the end surface on one side in the axial direction) of the mold body 2 is bonded to the members 60 to be bonded together by the SPR 50. This is a surface that comes into contact with a mold-side member-to-be-joined member 61 that is the member to be joined 60 closest to the mold 1. As shown in FIGS. 1 and 2, a chamfered portion 12 is formed at the corner between the upper surface 10 and the side surface 11 of the mold main body 2 over the entire periphery of the upper surface 10.

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

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

  As shown in FIG. 4, the leg 52 has a leg base 52a extending in the cylinder axis direction with a constant thickness, and an end of the leg base 52a opposite to the rivet head 51 from the end of the rivet head. 51 has a leg tip 52b that becomes narrower toward the opposite side. More specifically, the leg tip 52b has a radially outer portion that extends straight along the cylinder axis direction, while a radially inner portion faces the opposite side of the rivet head 51. It has a tapered shape that increases in diameter, and the thickness gradually decreases toward the outside in the radial direction. Since the leg portion 52 has the shape as described above, when the SPR 50 is driven into the member to be joined 60, the leg portion 52 is deformed so as to increase in diameter toward the outer side in the radial direction. The to-be-joined members 60 are firmly joined by the leg portions 52.

  Here, when the plurality of members to be bonded 60 are actually bonded to each other by the SPR 50, as shown in FIG. 5, the SPR 50 and the mold 1 are bonded to each other in a state where the plurality of members to be bonded 60 are overlapped. The SPRs 50 are respectively disposed so as to face each other with the member 60 interposed therebetween, and are 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 are deformed so as to bulge into the cavity 20. That is, the cavity 20 is a cavity that allows the SPR 50 to be swelled and deformed to the lower side (that is, the other side in the axial direction) of the plurality of members to be bonded 60 (particularly, the mold-side bonded member 61). .

  Then, in the state where the joining by the SPR 50 is completed, as shown in FIG. 8, the leg base 52a of the SPR 50 penetrates the joined member 60 other than the mold-side joined member 61 and the leg tip end 52b of the SPR 50. Bites into the mold-side bonded member 61.

  As described above, when the plurality of members to be bonded 60 are bonded to each other by the SPR 50, the deformation of the mold side bonded member 61 when the SPR 50 is driven is constrained by the mold 1, and the mold side bonded member 61. Cracks may occur. In particular, if the mold-side bonded member 61 is made of aluminum or a material whose indentation hardness is equal to or less than the indentation hardness of aluminum, there is a high possibility of cracking. When a crack occurs in the mold side bonded portion 61, the bonded member 60 may corrode from the cracked portion. For this reason, it is necessary to prevent the cracks appropriately.

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

  As shown in FIGS. 2 and 3, the cavity 20 includes a circular cavity bottom surface 21 and a cavity side surface 30 when viewed from the axial direction. The diameter Di2 of the cavity bottom surface 21 is set to a value smaller than the diameter Di1 at the opening end of the cavity 20. The diameter Di2 of the cavity bottom surface 21 is a diameter at the radially outer end of the outer bottom surface portion 23 described later of the cavity bottom surface 21, as shown in FIG. The definition of the diameter Di1 at the open end of the cavity 20 will be described later.

  2 and 3, the cavity bottom surface 21 has an average diameter of the inner diameter and the outer diameter of the legs 52 of the SPR 50 and is arranged on a virtual circle C concentric with the cavity bottom surface 21. A protruding portion 40 protruding upward from the bottom surface 21 is formed.

  As shown in FIG. 2, the protrusion 40 has an annular shape that is continuous over the entire circumferential direction of the virtual circle C. Thereby, the cavity bottom surface 21 is located inside the protrusion 40 in the radial direction by the protrusion 40 and has a circular shape when viewed from the axial direction, and the protrusion 40 in the radial direction. The outer bottom surface portion 23 is formed in a ring shape when viewed from the axial direction.

  As shown in FIGS. 2 and 3, the center bottom surface portion 22 is formed by a plane that extends in a direction orthogonal to the axial direction (that is, the horizontal direction). On the other hand, the outer bottom surface portion 23 is formed by a curved portion that is curved so that the radial intermediate portion is positioned below the both ends in the radial direction over the entire circumferential direction. As a result, the curved portion is formed on the outer side of the projecting portion 40 in the radial direction and between the projecting portion 40 in the radial direction and the cavity side surface 30.

  As shown in FIG. 3, the cavity side surface 30 extends from the radially outer end of the cavity bottom surface 21 (strictly speaking, the outer bottom surface portion 23) in an inclined manner outward in the radial direction toward the upper side. . More specifically, as shown in FIG. 3, the cavity side surface 30 includes an upper side surface portion 31 and an outer bottom surface portion that have an inclined curved surface that is continuous with the upper surface 10 in a cross section cut along the radial direction. The outer side in the radial direction toward the upper side so as to connect the lower side surface portion 32 having an inclined curved surface continuous with the upper surface portion 23, and the lower side end of the upper side surface portion 31 and the upper end of the lower side surface portion 32. And an inclined flat surface portion 33 (flat surface portion) extending in an inclined manner.

  The protrusion 40 is a flat surface in which the protrusion tip surface 41 extends in a direction orthogonal to the axial direction (that is, the horizontal direction) and has 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 body 2. In the protruding portion 40, the radially inner portion of the protruding tip surface 41 is an inner inclined portion 42 that is inclined downward toward the inner side in the radial direction. The outer portion in the radial direction is an outer inclined portion 43 that is inclined downward toward the outer side in the radial direction.

  As shown in FIG. 3, the inner inclined portion 42 has a substantially S shape in a cross section cut along the radial direction. More specifically, the inner inclined portion 42 has an upper inclined curved surface portion 42 a that has an inclined curved surface that is continuous with the protruding tip surface 41 and a lower inclined surface that has an inclined curved surface that is continuous with the central bottom surface portion 22. A curved surface portion 42b, and an inclined flat surface portion 42c extending obliquely outward in the radial direction toward the upper side 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. Have.

  On the other hand, similarly to the inner inclined portion 42, the outer inclined portion 43 is also substantially S-shaped in a cross section cut along the radial direction. More specifically, the outer inclined portion 43 includes an upper inclined curved surface portion 43 a that has an inclined curved surface that is continuous with the protruding tip surface 41 and a lower inclined surface that has an inclined curved surface that is continuous with the central bottom surface portion 22. The curved surface portion 43b is linearly extended in the axial direction and inclined upward in the radial direction so as to connect the lower end of the upper inclined curved surface portion 43a and the upper end of the lower inclined curved surface portion 43b. And an inclined flat surface portion 43c extending.

  In the first embodiment, the predetermined width W in the radial direction of the protruding tip 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, the diameter Di1 at the open end of the cavity 20 is, as shown in FIG. 3, a radial direction in a cross section obtained by cutting the mold main body 2 along a plane that passes through the center of the cavity bottom surface 21 and extends in the axial direction. The length between the intersections P of the two straight lines L1 extending upward along the inclined plane portion 33 of the cavity side surface 30 located on both sides of the cavity and the straight line L2 extending in the radial direction along the upper surface 10 Defined. And the said predetermined width W of the protrusion front end surface 41 is set to 10% or more length with respect to the diameter Di1 in the opening end of the cavity 20 defined as mentioned above.

  The diameter Di1 at the open end of the cavity 20 is determined corresponding to the diameter of the leg portion 52 of the SPR 50. Specifically, the leg portion 52 of the SPR 50 is suitable so that it can easily be deformed so as to easily penetrate the member to be joined other than the mold side member 61 to be joined among the plurality of members 60 to be joined. Is set to a value.

  In the first embodiment, the height H of the protrusion 40 from the deepest position of the cavity 20 is set to a value larger than 30% with respect to the depth D of the cavity at the deepest position of the cavity 20. ing. In the first embodiment, since the depth of the cavity 20 is deepest at the position of the central bottom surface portion 22 and the curved portion of the outer bottom surface portion 23 and each depth is the same, as shown in FIG. The height of the protruding portion 40 from the bottom surface portion 22 is set to a value larger than 30% with respect to the depth of the cavity 20 at the position of the central bottom surface portion 22.

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

  When the two members to be bonded 60 are bonded by the SPR 50, first, as shown in FIG. 5, the mold side target member 61 and the rivet side target member 62 are overlapped with each other. Both the joined members 61 and 62 are arranged so that the joining member 61 and the upper surface 10 of the mold 1 are in contact with each other. Next, as shown in FIG. 5, the SPR 50 is disposed so as to face the mold 1 with both the joined members 61 and 62 interposed therebetween. That is, the mold 1 is in a state of being disposed on the side opposite to the driving side of the SPR 50 in a portion where the SPR 50 is driven in a plurality (two in this case) of the members to be bonded 60. At this time, as shown in FIG. 5, the protruding portion 40 of the mold 1 is positioned at a position corresponding to the leg portion 52 of the SPR 50. Actually, the rivet joining apparatus is provided with a guide for determining the position of the mold 1 and a guide for guiding the arrangement and the entry direction of the SPR 50. Therefore, the mold 1 and the SPR 50 are arranged according to each guide. For example, the mold 1 and the SPR 50 have 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 joined members 61 and 62 are deformed so as to bulge into the cavity 20 as shown in FIG. 6. At this time, a portion corresponding to the leg portion 52 of the SPR 50 (hereinafter referred to as a leg portion corresponding portion 61 a) in the mold side bonded member 61 is extended and deformed outward in the radial direction of the cavity bottom surface 21. In addition, a portion on the inner side in the radial direction from the leg portion 52 (hereinafter, referred to as an inner deformation portion 61c) in the mold-side bonded member 61 is also the outer side in the radial direction in the same manner as the leg corresponding portion 61a. It is stretched and deformed. On the other hand, in the mold-side bonded member 61, a portion on the outside in the radial direction with respect to the leg portion 52 and on the inside in the radial direction with respect to the boundary portion between the cavity side surface 30 and the upper surface 10 of the mold body 2. (Hereinafter referred to as 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 bonded member 61 abuts against the protruding tip surface 41 of the protruding portion 40 of the cavity bottom surface 21, while the outer side of the mold side bonded member 61. The deformation portion 61b and the inner deformation portion 61c do not contact the cavity bottom surface 21 and the cavity side surface 30. That is, there are gaps between the radially inner and outer portions (the central bottom surface portion 22 and the outer bottom surface portion 23) of the cavity bottom surface 21 and the cavity side surface 30 with respect to the mold side bonded member 61. It is formed.

  When the SPR 50 is driven further toward the mold 1 from the state of FIG. 6, the rivet side 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 bonded member 61 is further deformed so as to bulge into the cavity 20. At this time, the leg corresponding portion 61a of the mold side bonded member 61 extends and deforms inward and outward in the radial direction. This is because the leg corresponding portion 61a is allowed to be deformed by the gap. The inner deformation portion 61c of the mold-side bonded member 61 moves so as to be pushed toward the central bottom surface portion 22 with the extension deformation of the leg portion corresponding portion 61a, and comes into contact with the central bottom surface portion 22. . Further, the outer deformed portion 61 b of the mold side bonded member 61 is bent and deformed downward toward the outer bottom surface portion 23 and the cavity side surface 30 along with the elongation deformation of the leg corresponding portion 61 a.

  When the SPR 50 is driven further into the mold 1 from the state of FIG. 7, the leg portion 52 of the SPR 50 expands outward in the radial direction due to the repulsive load from the mold 1 as shown in FIG. It bites into the mold side member 61 while being deformed. At this time, the outer deformed portion 61b of the mold side bonded member 61 is further bent and deformed downward, and is slightly pushed outward in the radial direction by the bite of the leg portion 52. The leg corresponding portion 61 a of the mold side member 61 is pushed by the leg 52 and moves inward in the radial direction. Then, as shown in FIG. 8, if the SPR 50 is driven to such an extent that the leg portions 52 of the SPR 50 are embedded in both of the members to be bonded 61, 62, the rivet-side bonded member 62 and the mold-side bonded Joining 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 61a of the mold-side bonded member 61 comes into contact with the protruding tip surface 41, the above-mentioned radial direction inside and outside of the protruding portion 40 A gap is formed to allow the deformation of the leg corresponding portion 61a. Thereby, when joining the some to-be-joined members 60 by SPR50, it can suppress as much as possible that the deformation | transformation of the mold side to-be-joined member 61 is restrained, As a result, a mold side to-be-joined member The occurrence of cracks in 61 can be suppressed.

  Here, if the predetermined width W of the protruding tip surface 41 in the radial direction of the cavity bottom surface 21 is too narrow, after the leg portion corresponding portion 61a of the mold-side bonded member 61 contacts the protruding tip surface 41, It becomes difficult to stretch and deform toward the inside and outside in the radial direction. In addition, the protrusion 40 may bite into the mold-side bonded member 61 and cause the mold-side bonded member 61 to crack. Therefore, in the present embodiment, the predetermined width W in the radial direction of the protruding tip surface 41 is set to the diameter Di1 at the opening end of the cavity 20, that is, through the center of the cavity bottom surface 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 plane portions 33 of the cavity side surface 30 located on both sides in the radial direction, and the upper surface 10 along the upper surface 10. The length between the two intersections P with the straight line L2 extending in the radial direction is set to 10% or more.

  Further, if the height H of the protrusion 40 from the deepest position of the cavity 20 is too low, when the leg corresponding portion 61a of the mold side bonded member 61 comes into contact with the protrusion tip surface 41, the protrusion 40 is more than the protrusion 40. In addition, a gap that allows deformation of the leg corresponding portion 61a is not sufficiently formed inside and outside in the radial direction. Therefore, in the first embodiment, the height H of the protrusion 40 from the deepest position of the cavity 20 is set to a value larger than 30% with respect to the depth D of the cavity 20 at the deepest position of the cavity 20. Has been.

  In the first embodiment, since the inner and outer inclined portions 42 and 43 have upper inclined curved surface portions 42 a and 43 a that are continuous with the protruding tip surface 41, the mold side bonded member 61 is cracked. Can be suppressed more appropriately. That is, assuming that edges are formed at the respective corners between the inner and outer inclined portions 42 and 43 and the protruding tip surface 41, the mold side bonded member 61 contacts the protruding tip surface 41. After that, when the SPR 50 is driven further toward the mold 1, the edge may bite into the mold-side joined member 61, and cracking may occur due to the biting of the edge. If the upper inclined curved surface portions 42a and 43a are formed on the inner and outer inclined portions 42 and 43 as in the first embodiment, the edge does not bite into the mold-side bonded member 61. It is suppressed more appropriately that the side bonded member 61 is cracked.

  Further, in the first embodiment, the cavity side surface 30 is inclined outward in the radial direction from the radial outer end of the cavity bottom surface 21 (strictly speaking, the outer bottom surface portion 23) to the upper side. When the SPR 50 is driven toward the mold 1, particularly when the leg portion 52 of the SPR 50 bites into the mold-side bonded member 61, the deformation of the outer deformable portion 61 b of the mold-side bonded member 61 is reduced. The outer deformation portion 61 is moderately pushed outward in the radial direction without being restrained by the mold 1. Thereby, the repulsive load from the cavity side surface 30 can be received moderately, and it can suppress appropriately that a crack arises in the mold side to-be-joined member 61. FIG.

  Therefore, in the first embodiment, the end surface (upper surface 10) on one side (upper side) in the axial direction is provided with the cylindrical mold main body portion 2 that abuts on the mold bonded member 61, and the mold main body portion 2 is provided. Is a portion from the end surface to the other side in the axial direction so as to allow bulging deformation of the mold side bonded member 61 to the other side in the axial direction due to the driving of the SPR 50 in a portion other than the peripheral portion of the end surface. The cavity 20 has a cavity 20 that is recessed as viewed from the axial direction and is circular, and the cavity 20 has a cavity bottom surface 21 that is circular as viewed from the axial direction, and a flat surface portion (inclined flat surface portion 33). The cavity bottom surface 21 has an average diameter of the inner diameter and the outer diameter of the legs 52 of the SPR 50 and is on the virtual circle C concentric with the cavity bottom surface 21. Protruding part 40 protruding to one side is formed The projecting portion 40 has an annular shape extending continuously in the entire circumferential direction on the virtual circle C, and the projecting tip surface 41 of the projecting portion 40 extends in a direction substantially orthogonal to the axial direction. The mold body is a plane having a predetermined width W in the radial direction, and the predetermined width W in the radial direction of the projecting tip surface 41 is a plane extending through the center of the cavity bottom surface 21 and extending in the axial direction. In the cross section of the section 2, two straight lines L1 respectively extending toward the one side in the axial direction along the plane portions of the two cavity side surfaces 30 located on both sides in the radial direction, and a mold A length of 10% or more with respect to the diameter Di1 at the opening end of the cavity 20 defined by the length between two intersections with the straight line L2 extending in the radial direction along the end face of the main body 1 Set to the most of the cavity 20 The height H of the projecting portion 40 from the right position is set to a height larger than 30% with respect to the depth D of the cavity 20 at the deepest position of the cavity 20, so that a plurality of joints are made by the SPR 50. When the members 60 are joined together, the deformation of the mold side joined member 61 is restrained as much as possible, and the occurrence of cracks in the mold side joined member 61 can be suppressed.

(Embodiment 2)
FIG. 9 shows a mold main body 102 of a rivet bonding mold 101 (hereinafter referred to as a mold 101) according to the second embodiment. In FIG. 9, the same reference numerals are given to portions common to the first embodiment. In the following description, detailed description of portions common to the first embodiment will be omitted.

  In the second embodiment, the shape of the cavity bottom surface 121 of the cavity 120 is different from those of the first and second embodiments.

  Specifically, in the third embodiment, as shown in FIG. 9, the central bottom surface portion 122 of the cavity bottom surface 121 is positioned below the outer bottom surface portion 123 of the cavity bottom surface 121. That is, the depth D1 of the cavity 120 at the position of the central bottom surface portion 122 is deeper than the depth D2 of the cavity 120 at the position of the outer bottom surface portion 123.

  At this time, since the deepest position of the cavity 120 is the central bottom surface portion 122, the height H ′ of the protruding portion 140 from the deepest position of the cavity 120 is the height of the protruding portion 140 from the central bottom surface portion 122. The height H ′ is set to be higher than 30% with respect to the depth D1 of the cavity 120 at the position of the central bottom surface portion 122.

  Even if configured as in the second embodiment, the SPR 50 is driven into the plurality of members to be bonded 60 toward the mold 1, and the leg corresponding portions 61 a of the mold side bonded members 61 are protruded portions 140. When the contact is made, the inner and outer portions (center bottom surface portion 122 and outer bottom surface portion 123) in the radial direction with respect to the protruding portion 140 on the cavity bottom surface 121, the cavity side surface 30, and the mold side bonded member 61 Since a gap that allows deformation of the leg corresponding portion 61a of the mold-side bonded member 61 is formed therebetween, the same effect as in the first embodiment can be obtained.

  Further, in the second embodiment, since the depth D1 of the cavity 120 at the position of the central bottom surface portion 122 is deeper than that in the first embodiment, the leg corresponding portion 61a of the mold side bonded member 61 is reduced. A gap as large as possible can be formed between the center bottom surface portion 122 and the mold-side bonded member 61 when it comes into contact with the protruding portion 40. Thereby, the leg | foot corresponding part 61a of the die side to-be-joined member 61 becomes easy to deform | transform. Further, when the leg portion 52 of the SPR 50 is deformed so as to expand in diameter, the leg portion corresponding portion 61a is easily moved toward the inside in the radial direction. As a result, it is possible to more effectively suppress the occurrence of cracks in the mold side bonded member 61. Moreover, since the leg part 52 of SPR50 becomes easy to deform | transform so that a diameter may be expanded, the joining strength of several to-be-joined members 60 can be ensured appropriately.

  The depth D1 of the cavity 120 at the position of the central bottom surface portion 122 is such that the inner deformed portion 61c of the mold side bonded member 61 is the central bottom surface portion in a state where the bonding of the plurality of bonded members 60 by the SPR 50 is completed. The depth is set so as to be in contact with 122.

(Embodiment 3)
10 and 11 show a mold main body 202 of a rivet joining mold 201 (hereinafter referred to as a mold 201) according to the third embodiment. 10 and 11, the same reference numerals are given to portions common to the first embodiment. In the following description, detailed description of portions common to the first embodiment will be omitted.

  In the third embodiment, the shapes of the cavity bottom surface 221 and the protrusion 240 of the cavity 220 are different from those of the first and second embodiments.

  Specifically, in the third embodiment, as illustrated in FIG. 10, a plurality of protrusions 240 are intermittently provided in the circumferential direction around the center of the cavity bottom surface 221 (six in the third embodiment). . More specifically, the plurality of protrusions 240 are intermittently formed on the virtual circle C.

  In the third embodiment, as shown in FIG. 11, the portion on the outer side in the radial direction of the cavity bottom surface 221 with respect to the protruding portion 240 on the cavity bottom surface 221 (the portion corresponding to the outer bottom surface portion in the first and second embodiments). ) Is flat and not curved downward.

  Even in the configuration of the third embodiment, the SPR 50 is driven into the plurality of members to be bonded 60 toward the mold 1, and the leg corresponding portions 61 a of the mold side members to be bonded 61 become the protrusions 240. When abutting, the legs of the mold-side member-to-be-joined member 61 are located between the radially inner and outer portions of the cavity bottom surface 221 and the cavity side surface 30 and the mold-side member-to-be-joined member 61. Since a gap allowing deformation of the part corresponding part 61a is formed, the same effect as in the first embodiment can be obtained.

  Further, in the configuration of the third embodiment, a gap that allows deformation of the leg corresponding portion 61 a of the mold-side bonded member 61 is also formed in the region between the adjacent protruding portions 240 in the circumferential direction of the virtual circle C. Therefore, it is possible to more effectively suppress the occurrence of cracks in the mold-side joined member 61.

  In FIG. 10, the plurality of protrusions 240 are arranged at equal intervals in the circumferential direction of the virtual circle C, but the protrusions 240 are not necessarily arranged at equal intervals in the circumferential direction. However, from the viewpoint of deforming the leg-corresponding portions 61a, the outer deforming portions 61b, and the inner deforming portions 61c of the mold-side joined member 61 as uniformly as possible, the protruding portions 240 are arranged at equal intervals in the circumferential direction. It is desirable that Further, the number of the protrusions 240 may be five or less, or seven or more as long as cracks can be prevented from occurring in the mold side bonded member 61.

(Other embodiments)
The present invention is not limited to the embodiment described above, and can be substituted without departing from the spirit of the claims.

  For example, in the above-described embodiment, the case where two members to be bonded 60 are bonded has been described. 1 (101, 201) can be used.

  Moreover, in the said Embodiment 1 and 2, although the protrusion part 40 (140) comprised the annular | circular shape extended continuously in the whole circumferential direction of the virtual circle C, it is not restricted to this, The circumferential direction of the virtual circle C A C-shape may be formed which extends continuously to a part of the shape.

  Further, in the first to third embodiments, the mold body 2 has a cylindrical shape. However, the present invention is not limited to this. It may be prismatic.

  Moreover, in the said Embodiment 1-3, although the protrusion front end surface 41 was made into the plane which spreads in the direction orthogonal to the axial direction of the metal mold | die main-body part 2, it is not restricted to this, The mold side side to-be-joined member 61 is used. If it is possible to prevent the occurrence of cracks, it may be slightly inclined upward inward or outward in the radial direction.

  The above-described embodiments are merely examples, and the scope of the present invention should not be interpreted in a limited manner. The scope of the present invention is defined by the scope of the claims, and all modifications and changes belonging to the equivalent scope of the claims are within the scope of the present invention.

  INDUSTRIAL APPLICATION This invention is useful as a metal mold | die for rivet joining used when joining several to-be-joined members by a self-piercing rivet.

1,101,201 Rivet bonding mold 2,102,202 Upper surface of mold body 10 (end surface on one side in the axial direction of the mold body)
20, 120, 220 Cavity 21, 121, 221 Cavity bottom surface 22, 122 Central bottom surface portion 23, 123 Outer bottom surface portion 30 Cavity side surface 33 Inclined flat surface portion (planar portion of cavity side surface)
40, 140, 240 Protruding part 41 Protruding tip surface 50 Self-piercing rivet 52 Leg part 60 Joined member 61 Mold side joined member C Virtual circle D Cavity depth D1 at the deepest position of the cavity D1 Cavity depth D2 Cavity depth Di1 at the position of the outer bottom surface portion Di1 Diameter Di2 at the open end of the cavity Diameter H of the cavity bottom surface H, H ′ Height of the protrusion from the deepest position of the cavity W width

Claims (6)

When the plurality of members to be joined are joined to each other by the self-piercing rivet having a substantially cylindrical leg in a state where the plurality of members to be joined are overlapped, the self-piercing rivet in the plurality of members to be joined is In the portion to be driven, a rivet joining mold disposed on the side opposite to the driving side of the self-piercing rivet,
A column-shaped mold main body that is in contact with a mold-side bonded member, which is the bonded member closest to the mold, has an end surface on one side in the axial direction,
The mold main body bulges the mold-side joined member to the other side in the axial direction by driving the self-piercing rivet into a portion excluding the outer peripheral edge of the end surface on the one side in the axial direction. In order to allow deformation, it has a cavity that is recessed from the end face toward the other side in the axial direction, and has a circular shape when viewed from the axial direction,
The cavity is constituted by a cavity bottom surface having a circular shape when viewed from the axial direction, and a cavity side surface having a flat portion,
On the bottom surface of the cavity, a protruding portion having an average diameter of the inner diameter and the outer diameter of the legs of the self-piercing rivet and projecting to the one side in the axial direction on a virtual circle concentric with the bottom surface of the cavity Formed,
One of the protrusions is provided so as to continuously extend on the virtual circle, or a plurality of the protrusions are provided intermittently on the virtual circle,
The protrusion tip surface of the protrusion when there is one protrusion and the protrusion tip surface of each protrusion when there are a plurality of protrusions extend in a direction substantially orthogonal to the axial direction and in the radial direction. A plane having a predetermined width;
The predetermined width in the radial direction of the protruding tip surface is 2 located on both sides in the radial direction in a cross section obtained by cutting the mold main body by a plane passing through the center of the cavity bottom surface and extending in the axial direction. Two straight lines each extending toward the one side in the axial direction along the plane portion of the two cavity side surfaces, and the radial direction along the end surface on the one side in the axial direction of the mold body portion Set to a length of 10% or more with respect to the diameter at the open end of the cavity defined by the length between two intersections with a straight line extending to
The height of the protrusion 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. In the rivet joining mold according to claim 1,
The cavity bottom surface has a central bottom surface portion located inside the projecting portion in the radial direction and an outer bottom surface portion located outside the projecting portion in the radial direction,
The outer bottom surface portion is formed with a curved portion that is curved so that the radial intermediate portion is positioned on the other side in the axial direction with respect to both ends in the radial direction. Die for rivet joining. In the rivet bonding mold according to claim 2,
The depth of the cavity at the position of the center bottom surface portion is deeper than the depth of the cavity at the position of the outer bottom surface portion,
The height of the projecting portion from the center bottom surface portion is set to a height greater than 30% with respect to the depth of the cavity at the position of the center bottom surface portion. Type. In the rivet bonding mold according to any one of claims 1 to 3,
The rivet-joining mold, wherein the protrusion has an annular shape extending continuously over the entire circumferential direction of the virtual circle. In the rivet bonding mold according to any one of claims 1 to 3,
A plurality of the protrusions are intermittently formed on the virtual circle,
The rivet joining mold, wherein the plurality of protrusions are arranged at equal intervals in the circumferential direction of the virtual circle. In the rivet bonding mold according to any one of claims 1 to 5,
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,
The cavity side surface is inclined outward in the radial direction toward the one side in the axial direction,
The mold for rivet bonding, wherein the flat portion on the side surface of the cavity is an inclined flat surface.

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