Specification
Title of invention: Lap joint structure
Technical field
[0001]
　TECHNICAL FIELD The present invention relates to a lap joint structure in which a plurality of plate members cut out from a plate or plate members formed from the plates are overlapped with each other and the overlapped parts are joined with each other by a plurality of non-melted joints.
Background technology
[0002]
　2. Description of the Related Art Conventionally, spot welding has been widely used in the field of automobiles for assembling a vehicle body, attaching parts, and the like, and joining of a plurality of steel plate members including high-strength steel plates is also performed by spot welding.
　However, in a spot-welded joint including a steel sheet having a tensile strength of 780 MPa or more, the toughness of the nugget decreases, and the stress in the peeling direction concentrates the stress on the nugget end, so that the tensile strength of the steel sheet increases. However, there is a problem that the cross tensile strength (CTS) does not increase or decreases.
　As one of the techniques for solving this problem, there is a technique for mechanically joining a plurality of metal plates using a mechanical joining means such as a rivet or a screw without melting the base material. By using this technology, it is possible to manufacture automobile parts with higher strength reliability than before.
[0003]
　Further, in the body of an automobile or the like, a combination of different materials such as a steel plate and an aluminum plate, or a steel plate and a carbon fiber reinforced plastic (CFRP) plate may be bonded for the purpose of weight reduction. In this way, when the materials to be combined are materials having different physical properties such as melting point and linear expansion coefficient, fastening/joining is performed by mechanical joining means as described in Patent Documents 1 and 2, for example. .. Further, in an aluminum plate having a low electric resistance, friction stir spot welding may be used instead of resistance spot welding.
Prior art documents
Patent literature
[0004]
Patent Document 1: Japanese Patent Laid-Open No. 2000-272541
Patent Document 2: Japanese Patent Laid-Open No. 2005-119577
Summary of the invention
Problems to be Solved by the Invention
[0005]
　When joining the superposed portions of a plurality of superposed plate members at a joint portion by a mechanical joining means such as a blind rivet, a hole through which a rivet is inserted is formed at the joint portion of the plate members. Further, when the overlapping portion is spot-joined by the friction joining means, a hole due to the press-fitted trace of the probe at the tip of the rotary tool remains in the joint portion of the plate member on the rotary tool side.
　In the study by the present inventor, in the lap joint member in which the lap portion is joined by mechanical joining means or friction joining means, when the entire lap joining member undergoes tensile deformation, strain is concentrated in the holes formed in the joint portion. As a result, the test No. of FIG. As shown in Fig. 1, there is a problem that the plate member is broken by the small deformation starting from the hole.
　In the present invention, the mechanical joining means and the friction stir spot joining means may be collectively referred to as non-melt joining means.
[0006]
　Therefore, in the present invention, when the overlapping portion formed by stacking a plurality of plate members is joined by the non-melt joining means, it is possible to suppress the plate member from breaking from the hole formed at the time of joining as a starting point. It is an object of the present invention to provide a lap-joint structure of lap-joint members capable of performing the above.
Means for solving the problem
[0007]
　In the present invention, with respect to such a problem, a means for dispersing strain so as not to concentrate at the end of the hole formed in the joint was examined. As a result, in the overlapping portion of the plate member, by forming a notch recessed portion in the direction from the end portion of the overlapping portion toward the joint portion between the adjacent joint portions, a structure that disperses strain due to a tensile load is formed. It was found that the breakage of the lap joint member starting from is suppressed.
　The present invention has been made based on such knowledge, and the summary thereof is as follows.
[0008]
(1) Overlapping portions of a plurality of plate members are joined at a plurality of joining portions in a dot shape by a mechanical joining means or a friction stir spot joining means, and at least one plate member is mechanically joined to the joining portion. In a lap joint structure in which a hole through which the static joining means is inserted or a hole formed during point joining by the friction stir spot joining means is present,
　at least one of the plate members is provided with a lap portion. , A cutout concave portion is formed between the adjacent joint portions in the direction of the joint portion from an end portion of the overlapping portion, and
　an inner bottom portion of the notch concave portion has the inner diameter of the hole as K, the overlapping portion The lap joint structure is characterized in that it is formed at a position deeper than K from the end of the.
[0009]
(2) The distance L between the end of the hole and the end of the plate member in which the cutout recess is formed satisfies the relationship of L≧0.8K with respect to the inner diameter K of the hole. The lap joint structure according to (1) above, wherein the holes are located.
(3) The lap joint structure according to (1) or (2), wherein the hole is a through hole that penetrates the at least one plate member.
[0010]
(4) The lap joint structure according to any one of (1) to (3) above, wherein the shortest distance between the end of the hole and the end of the cutout recess is 0.8K or more. ..
(5) The lap joint structure according to any one of the above (1) to (4), wherein the cutout recess is formed in a plate member having at least the hole.
[0011]
(6) In any one of the above (1) to (5), the inner bottom portion of the cutout concave portion is formed so as to enter up to a range of 1.5K or more from the end portion of the overlapping portion. The lap joint structure described.
(7) The lap joint structure according to any one of the above (1) to (6), wherein an inner bottom portion of the cutout recess portion has a parallel portion that is parallel to an end portion of the overlap portion.
(8) The lap joint structure according to (7) above, wherein the parallel portion has a length of 0.5 K or more.
[0012]
(9) The plate member in which the cutout recess is formed is a hat-shaped member having a hat-shaped cross section in which a bent portion is formed on the opposite side of the end portion of the overlapping portion with the joint portion interposed therebetween. The lap joint structure according to any one of the above (1) to (8), wherein the recessed recess is formed in a range closer to the end than the bent portion of the hat-shaped member.
(10) In any one of (1) to (9) above, the plate member is a steel plate member, and the notch recess is formed in a steel plate member having a tensile strength of 590 MPa or more. The lap joint structure described.
[0013]
(11) The mechanical joining means is any one of a blind rivet, a self-piercing rivet, a drill screw, a bolt and a resistance element welding, according to any one of the above (1) to (10). Lap joint structure.
(12) The lap joint structure according to any one of the above (1) to (11), characterized in that, in addition to the joint by the mechanical joint means or the friction stir spot joint means, joint by resin is also used. ..
Effect of the invention
[0014]
　According to the present invention, when a plurality of metal plate members or CFRP plate members are joined by a non-melt joining means, a hole through which a mechanical joining means is inserted or a point formed by a friction stir spot joining means is formed. It is possible to prevent the joint from breaking from the hole.
　As a result, for example, it is possible to manufacture a high-strength automobile part having excellent occupant protection performance in the event of a collision.
Brief description of the drawings
[0015]
FIG. 1 is a perspective view for explaining a schematic configuration of a lap joint member of the present invention.
FIG. 2 is a view of the lap joint member shown in FIG. 1 viewed from the plate thickness direction.
3 is a vertical cross-sectional view of the lap joint member shown in FIG. 2, (A) is a vertical cross-sectional view taken along the arrow IIIA-IIIA, and (B) is a vertical cross-sectional view taken along the arrow IIIB-IIIB. It is a figure.
FIG. 4 is a photograph showing the state of a test piece before and after a tensile test for confirming the effect of the present invention, (A) shows a case where a test piece in which two identical test pieces are stacked is used, (B) shows a case where two identical test pieces are stacked and mechanically joined with a blind rivet, and (C) uses a test piece in which a cutout recess is further provided in the test piece of (B). The case is shown.
FIG. 5 is a load-strain curve diagram showing the result of a tensile test for confirming the effect of the present invention.
FIG. 6 is a diagram for explaining resistance element welding, which is a type of mechanical joining means.
FIG. 7 is a diagram for explaining the positions of the holes in the joint portion, where (A) shows a case where the end portions of the plate members in the overlapping portion coincide, and (B) shows a case where the end portions of the plate member do not coincide. The case (the case where the end of the plate member forming the cutout recess is located closer to the joint than the other end) is shown.
FIG. 8 is a diagram for explaining another form of the cutout recess provided in the overlapping portion of the plate members.
FIG. 9 is a diagram for explaining another form of the cutout recess provided in the overlapping portion of the plate members.
FIG. 10 is a view for explaining the schematic configuration of the lap joint member 7 according to the form shown in FIG. 9, as seen from the plate thickness direction.
FIG. 11 is a vertical cross-sectional view illustrating a schematic configuration of the lap joint member 7 according to FIGS. 9 and 10, (A) is a vertical cross-sectional view taken along line XA-XA in FIG. 10 is a vertical sectional view taken along line XB-XB in FIG.
FIG. 12 is a view for explaining another form of the cutout recess provided in the overlapping portion of the plate members.
FIG. 13 is a diagram illustrating the form of a cutout recess provided in the overlapping portion of the plate members.
FIG. 14 is a diagram illustrating another form of the cutout recessed portion provided in the overlapping portion of the plate members.
FIG. 15 is a diagram explaining an example in which the lap joint structure of the present invention is applied to a B pillar of an automobile, (A) is a perspective view showing the B pillar, and (B) is a two-point structure in (A). The figure which expanded the range shown by the dashed line B is shown.
FIG. 16 is a diagram illustrating an example in which the lap joint structure of the present invention is applied to a roof rail of an automobile, (A) is a perspective view showing the roof rail, and (B) is a chain double-dashed line B in (A). In the figure, (C) shows an enlarged view of the range indicated by the alternate long and two short dashes line C in (A).
FIG. 17 is a diagram illustrating an example in which the lap joint structure of the present invention is applied to a bumper of an automobile, (A) is a perspective view showing the bumper, and (B) is a chain double-dashed line B in (A). The figure which expanded the range shown by is shown.
FIG. 18 is a diagram illustrating an example in which the lap joint structure of the present invention is applied to a B-pillar outer reinforcement member of an automobile, (A) is a perspective view showing the B-pillar outer reinforcement member, and (B) is a perspective view thereof. FIG. 13A is a vertical sectional view taken along line XVIB-XVIB in FIG. 7A, and FIG. 8C is a vertical sectional view taken along line XVIC-XVIC in FIG.
FIG. 19 is a photograph showing the state of test pieces before and after the tensile test in Examples.
MODE FOR CARRYING OUT THE INVENTION
[0016]
　First, a basic embodiment of the present invention will be described using an example in which one plate member is a hat-shaped member and the other plate member is a plate-shaped member as a lap joint structure.
[0017]
　As shown in FIGS. 1 and 2, the lap joint member 1 includes a plate-shaped member 10, a hat-shaped member 20, and a plurality of joints (joints) SP formed by a non-melting joint means. The flange portion 11 and the flange portion (flange piece 22) of the hat-shaped member 20 are joined together by a mechanical joining means such as a blind rivet or a friction stir spot joining means.
[0018]
　In the flange portion of the hat-shaped member 20, a cutout recess 22U is formed from the outer end 22C of the overlapping portion between the adjacent joints SP and the joints SP, whereby the hat-shaped member 20 has a recessed portion. The flange portion includes a plurality of flange pieces 22 and a connecting portion 22A that connects between the flange pieces 22, and a cutout recess 22U is formed between the adjacent flange pieces 22 and the flange pieces 22. It is configured to be.
[0019]
　In the example of FIGS. 1 and 2, the cutout recess 22U is opened at the end 22C of the flange portion of the hat-shaped member 20, and is formed by connecting the outer circumferences of the adjacent joints SP on the side opposite to the end 22C. It is formed so as to enter the inside of the flange rather than the boundary line (the line X connecting the ends of the holes).
　In addition, as shown in FIGS. 3A and 3B, the cutout recess 22U has a bending starting point (of the corner R that transitions to the bending portion 22R from the flange portion of the hat-shaped member 20 to the rising wall portion 21 side). It is set so that the connecting portion 22A is formed in a range where it does not catch on the other flange end portion) 22B.
[0020]
　In the lap joint member 1, one or both of the plate-shaped member 10 and the hat-shaped member 20 that form a flange cold-rolls a steel plate (for example, a high-strength steel plate having a tensile strength of 590 MPa or more). Or a hot stamp material having a martensite structure formed by hot stamping a steel sheet for hot stamp material (b) (for example, a steel sheet member having a tensile strength of 1200 MPa or more). ..
　Further, one may be an aluminum material and the other may be the steel plate of (a) or (b), or both may be an aluminum material. Similarly, one may be a CFRP material, or both may be CFRP materials.
[0021]
　As described above, when the overlapping portions of the plurality of plate members are non-melt-bonded, at least one of the members has a hole through which the mechanical joining means is inserted and a hole associated with the friction stir spot joining. For example, when non-melt welding is applied to the joining of the steel plate members of the vehicle body structural member of the vehicle, strain concentration occurs at the edge of the hole due to the load load at the time of collision input, and breakage easily occurs.
　However, in the lap joint member 1, since the notch recess 22U is formed between the non-melt joint means (joint portion) of the lap portion, an external force is applied to the lap joint member 1 so that the tensile stress in the arrow F direction is generated. Even if it occurs, the notch recesses can disperse the load and deformation due to the tensile load (that is, the notch recesses can absorb the deformation and increase the elongation until breakage), so that the hole is the starting point for joining. The breakage of the members is suppressed, and the performance of the joining member can be sufficiently exhibited.
[0022]
　The effect of such a notch concave portion will be described in detail in Examples below, but confirmed by the following experiment.
　That is, test pieces (A), (B), and (C) before the tensile test shown in FIG. 4 were prepared.
　For each test piece, two steel sheet base materials made of cold-rolled steel sheets having tensile strengths of 980 MPa and 590 MPa and having a constricted central portion were used.
　The test piece of (A) is simply a stack of two base materials, and the test piece of (B) is one in which the base materials are joined by a blind rivet at a position on the left side of the central part, and a hole is formed by mechanical joining. The test piece of (C) is a test piece of (B) in which a notch recess is provided on the right side of the blind rivet.
[0023]
　A tensile test was performed using the test pieces (A) to (C).
　FIG. 4 shows a fractured state of the test piece after the tensile test, and FIG. 5 shows a load-strain curve diagram when a tensile load is applied to each test piece.
　As shown in FIG. 4, the test piece (B) not provided with the cutout recessed portion was fractured around the hole of the joint portion, whereas the test piece (C) provided with the cutout recessed portion was cut. The fracture occurs near the corners of the notched recesses, and the strain amount at which the fracture occurs with a tensile load is significantly higher in the test piece (C) than in the test piece (B) as shown in FIG. It was confirmed to increase.
　This is because, in the test piece (C), when a tensile load was applied, the strain was suppressed from concentrating on the edge of the hole through which the blind rivet was inserted, so that the deformation amount at which the lap joint member ruptured increased. is there. It is considered that such a mechanism suppresses breakage with a small strain starting from the edge of the hole provided in the mechanical joint.
[0024]
　As described above, according to the present invention, when the plurality of plate members are lap-joined by the mechanical joining means or the friction stir spot joining means, a notch recess is formed between the joining portions by the mechanical joining means or the friction stir spot joining means. Although provided, the individual requirements and preferable requirements constituting the present invention will be further described below.
[0025]

　The lap joining member of the present invention has a structure in which a plurality of plate members are overlapped with each other and the plate members are mechanically joined at the overlapped portion or by friction stir spot joining means. For example, as shown in FIGS. 1 and 2, a flange portion (flange equivalent portion) 11 of a plate-shaped member (plate member) 10 and a flange portion (flange piece 22 and its connecting portion 22A) of a hat-shaped member (plate member) 20. And a plurality of flange pieces 22 are overlapped with each other, and the metal plate members are joined by the joining portion SP by the mechanical joining means at the overlapping portion where the flange portion 11 and the plurality of flange pieces 22 are overlapped.
[0026]
　Such a lap joint member is applied to the formation of various structures such as automobile parts (Assy parts) such as a monocoque body forming an automobile body and A pillars and B pillars forming the monocoque body. To be done.
[0027]
　As the plate member, a metal plate such as a steel plate or an aluminum plate or a plate-like member cut out into a predetermined shape from a CFRP plate is used, and a forming member formed into a predetermined shape from the plate-like member is also used. A plurality of plate-shaped members or molded members are combined and at least a part thereof is overlapped, and the overlapping portions are bonded by non-melt bonding means (mechanical bonding means or friction stir point bonding means).
　The overlapping portion of the plate member is generally a flange (overlap portion) formed on the edge of the plate member as a joint margin with another plate member, but is not limited to the flange, and the flange and the shape portion are not limited. It may be joined by a non-melting joining means to a portion where the above (the portion other than the flange) is overlapped.
[0028]
　The number of plate members to be superposed is usually 2 to 3, but it is possible to superimpose more than that.
　Although it is not necessary to set a limit on the plate thickness of the plate member, from a practical point of view, the lower limit of the metal plate member can be 0.5 mm, and the upper limit thereof is preferably 2.6 mm. Is. In CFRP, the lower limit may be 0.3 mm and the upper limit is preferably 4.0 mm.
[0029]
　Various types of plate members can be used, but in the case of steel plate members, the strength was increased by heating cold press-formed products and steel plates for hot stamping above the austenite temperature and quenching while forming them in a water-cooled mold. An example is a hot stamped product having a tensile strength of 1200 MPa or more. Alternatively, a hot stamp molded product having a tensile strength of 1200 MPa or more may be heat-treated to reduce the strength of a portion where mechanical joining is performed to about 590 MPa, so that a through hole can be easily opened. ..
　The steel plate member to be laminated with the above steel plate member may be a high strength steel plate having a tensile strength of 1200 MPa or more or a hot stamp material, or a steel plate having a tensile strength of 270 MPa to 980 MPa. The steel sheet may be a cold rolled steel sheet or a hot rolled steel sheet.
[0030]
　Further, in the case of a steel plate, an unplated steel plate having no surface plated or galvannealing (GA plating), hot dip galvanizing (GI plating), electrogalvanizing (EG), Zn-Al plating, Zn A steel plate coated with a zinc-based plating such as -Al-Mg plating, an aluminum-plated steel plate, or the like may be targeted. In the case of hot stamping material, non-plating, aluminum plating, or an intermetallic compound of iron and aluminum, or a steel plate member coated with an iron-zinc solid solution layer and a zinc oxide layer, an iron zinc nickel solid solution layer and zinc oxide Steel sheet members coated with layers may be targeted.
[0031]
　In mechanical joining, it is possible to join materials that are not compatible with welding, and for example, the present invention can be applied to structural members in which a plurality of aluminum materials are combined or structural members in which aluminum materials and steel materials are combined. Further, it can be applied to a structural member using a CFRP material instead of the metal member.
　Friction stir point welding can also be used to join materials that are not compatible with welding. For example, the present invention can be applied to structural members in which a plurality of aluminum materials are combined or structural members in which aluminum materials and steel materials are combined.
[0032]
Non-melting joining
　used for lap joining of plate members includes mechanical joining and friction stir spot joining.
　Blind rivets, self-piercing rivets (self-piercing rivets), hollow rivets, drill screws, bolts, EJOWELD (registered trademark), FDS (registered trademark) and the like are used as the mechanical joining means. In mechanical joining, there are cases where all of the overlapped metal plate members such as blind rivets are penetrated, and cases where some of the overlapped metal plate members such as self-piercing rivets are not penetrated. The present invention can be applied in any case.
　Also, resistance element welding (REW) may be used as the mechanical joining means. As shown in FIG. 6, this REW overlaps an upper plate 210 (for example, an aluminum alloy plate) having a hole 215 penetrating in the plate thickness direction with a lower plate 220 (for example, a steel plate such as boron steel). The plate set 200 is formed together, and a steel flanged rivet 250 is inserted into the hole 215 of the upper plate 210. Further, the flanged rivet 250 of the plate set 200 is inserted using the upper electrode 230 and the lower electrode 240. While sandwiching the portion corresponding to (see (A) of FIG. 6), the plate assembly 200 is energized at a predetermined current value, so that the tip portion of the flanged rivet 250 and the lower plate 220 come into contact with each other. It is a joining means that fuses to form the nugget 255 (see FIG. 6B).
　As described above, although REW partially utilizes the fusion joining means, it is essentially a joining means utilizing the mechanical element of the flanged rivet 250. Therefore, such joining means is also mechanically joined. As a means, it can be preferably used in the present invention.
[0033]
　The friction stir spot welding can be applied to spot welding using a rotary tool having a probe at the tip. In that case, it is preferably applied when a hole having a depth of 80% or more of the plate thickness is formed by press fitting of the probe.
　In addition, when a resin is interposed on the overlapping surface and jointing with the resin is also used, for example, when an adhesive (for example, an epoxy resin adhesive) is interposed on the overlapping surface and jointing with the adhesive is also used. The present invention can also be applied to a case where a sealing resin (sealer) is interposed on the overlapping surfaces to waterproof or insulate the joint. It is a preferred mode of the present invention to jointly use an adhesive by interposing a structural adhesive or an impact resistant adhesive on the overlapping surfaces. In particular, in the case of a structural member made of a combination of aluminum and steel, it is desirable to use a resin or an adhesive having a sealing function capable of electrically insulating it.
[0034]
The position of the joint part is higher than that of the end part of the hole 30 because the risk of breaking at the hole increases if the position of the hole formed in the joint part is too close to the end part of the plate member. As shown in FIGS. 7A and 7B, the shortest distance from the end 22C of the plate member having the cutout recess 22U is L, and the shortest distance L is the inner diameter (equivalent circle diameter) K of the hole. On the other hand, it is preferable that the holes are provided at positions satisfying the condition of L≧0.8K. When cutout recesses are formed at the edges of a plurality of overlapping plate members as in the example shown in FIGS. 9 and 10 described below, L≧L for all plate members in which the cutout recesses are formed It is preferable to satisfy the condition of 0.8K.
　Further, the shortest distance M (see FIG. 7A) between the end of the hole 30 and the end of the flange piece 22 (the end of the cutout recess 22U) is also preferably 0.8K or more, More preferably, it is 1.5K or more.
　The pitch of the joints (distance between adjacent joints) is usually about 20 mm to 100 mm, but is not limited to this, and may be appropriately set according to the target structure and its site. Good.
　In the present invention, the hole formed in the joint may be a non-through hole that does not penetrate the plate member in which the hole is formed or a through hole that penetrates at least one plate member.
[0035]

[Basic Aspect of
　Notched Recess ] The notched recess 22U is opened at an edge portion such as a flange portion forming the overlapping portion. For example, in a hat-shaped member, the notched recess portion 22U has a thick flange portion. A part in the flange width direction of a region which is formed so as to penetrate in the depth direction and is located between the joint portions SP by the mechanical joint means arranged adjacent to the end portion of the flange portion, or the bending of the hat-shaped member. It is configured to extend to the vicinity of the starting point of the portion (the bending starting point 22B indicated by the one-dot chain line in FIG. 2 and the like) (the corner R that moves to the bending portion 22R). A connecting portion 22A is formed between the cutout recess 22U and the bent portion of the hat-shaped member.
[0036]
　The notch recesses are formed between adjacent joints as in the example of FIGS. 1 and 2, but when a large number of joints are provided (when the gap between the joints is narrow), the notch recesses of FIG. As described above, it is possible to provide a portion where the cutout recess is not formed (that is, two or more joints are provided between the cutout recesses adjacent to each other in the longitudinal direction).
[0037]
　In the example of FIG. 8, a plurality of the flange pieces 271 and the flange pieces 272 are alternately formed along the longitudinal direction of the lap joining member 1E, and there is a cut between the adjacent flange pieces 271 and the flange pieces 272. A notched recess 27U is formed.
　The flange piece 271 has cutout recesses 27U formed on both sides in the longitudinal direction, and has a size capable of forming one joint SP. The flange piece 272 has cutout recesses 27U formed on both sides in the longitudinal direction, and has a size capable of forming two (plural) joints SP.
[0038]
[Location
　of Notch Recess ] The notch recess is formed on at least one plate member of the plate members to be overlapped. As in the example of FIGS. 9 and 10, it may be provided on all the plate members of the overlapping portion.
　In the three-layered member, the cutout recess may be formed on one plate member or two plate members, or may be formed on three plate members. In the case of self-piercing rivets, even if notched recesses are formed in all stacked plate members including plate members in which through holes are not formed, notch recesses are formed only in the plate members in which the through holes are formed during joining. Alternatively, the notch recess may be formed only in the plate member having the high tensile strength×the plate thickness among the plate members having the through holes.
　From the standpoint that the effect of the present invention can be obtained more reliably, it is preferable that the cutout recess be formed in at least the plate member having the hole.
[0039]
　In the example of FIGS. 9 and 10, the lap joint member 7 includes a first hat-shaped member (plate member) 710, a second hat-shaped member (plate member) 720, and a joint portion (joint portion) SP formed by mechanical joining means. And a flange portion of the first hat-shaped member 710 and a flange portion of the second hat-shaped member 720 are overlapped with each other by a mechanical joining means MJ.
[0040]
　The flange portion of the first hat-shaped member 710 is provided with a flange piece 712 and a connecting portion 712A for connecting the adjacent flange pieces 712, and between the adjacent flange pieces 712 and 712. A notched recess 712U is formed. Similarly, the flange portion of the second hat-shaped member 720 is also formed with a connection portion 722A and a notch recess 722U between adjacent flange pieces 722. The cutout recess 712U and the cutout recess 722U are formed to overlap each other in the overlapping portion.
[0041]
　In this example, the rising wall portion 711 of the first hat-shaped member 710 and the rising wall portion 721 of the second hat-shaped member 720 are erected as shown in (A) and (B) of FIG. The upper wall portion 711 is located inward of the rising wall portion 721 and is displaced.
　Then, the cutout recess 712U is on the side of the rising wall 711 from the flange of the first hat-shaped member 710, and within the range where it does not get caught at the bending start point 712B of the corner R that transitions to the bending portion 711R. Are set to be formed. Similarly, in the cutout recess 722U, on the side of the rising portion 721 from the flange portion of the second hat-shaped member 720, the flange portion is connected within a range where it does not get caught at the bending start point 722B of the corner R that transitions to the bending portion 722R. It is set so that the portion 722A is formed.
[0042]
　The bending start point 722B is located outward of the bending start point 712B in the width direction of the flange portion, and is formed at a position shown by a dashed line in FIG. Further, the cutout recess 712U is formed in a range outward in the width direction of the flange portion with respect to the bending start point 712B.
[0043]
[Shape of
　Notch Recess ] In FIG. 1, the notch recess is formed in a trapezoidal shape in which the opening side of the plate member end in the overlapping portion is long and the bottom side inside the plate member is short. The cutout recess may be formed in an inverted trapezoidal shape in which the opening side of the plate member end in the overlapping portion is short and the bottom side inside the plate member is long, and as shown in FIG. It may be formed in a U-shape (rectangular shape) whose sides are parallel to each other.
　Each corner of the cutout recess is preferably formed by a curved line. Further, it is preferable that the inner bottom portion of the cutout recess portion has a parallel portion parallel to the end portion 22C of the overlapping portion. The length of the parallel portion can be set to 0.5 times or more of K, preferably 1 times or more of K, more preferably K, when the inner diameter of the hole of the joining portion is K. 2 times or more, more preferably 3 times or more, and most preferably 4 times or more.
[0044]
[Formation Depth of
　Notch Recess ] The position of the inner bottom of the notch recess 22U (depth of the recess) can be appropriately set according to the structure of the plate member to be applied, the assumed load stress, etc. With respect to the inner diameter K of the above, it is necessary to form at least the outer end 22C of the overlapped portion on the opposite side (inner side) from the end 22K or more to the end. It is more preferably 1.2K or more, and even more preferably 1.5K or more in which the bottom is inside the end of the hole.
[0045]
　Further, the maximum depth can be set to the depth up to the starting point of the bent portion of the flange (bending starting point 22B indicated by the alternate long and short dash line) when at least one of the overlapping portions is a flange.
　For example, when the notch concave portion is formed so as to penetrate into the flange width of the plate member to a range of ½ or more, the region between the joint portions has a width of ½ or more from the end side. It is expected that the tensile stress will be dispersed and the tensile stress transmitted between the joints and the same soil will be 1/2 or less, and further the connected region (connecting portion 22A) in which the notch recess is not formed is dispersed. Providing resistance to tensile stress. When the cutout recess is formed so as to include the entire widthwise direction of the flange, tensile stress does not act between the joints.
　When the overlapping portion is not a flange portion or when the width of the entire lap joint member is narrow, the formation depth of the notch recess is determined by considering the influence of the provision of the notch recess on the strength of the entire lap joint member. There is a need.
[0046]
　An example of the formation depth of the notch concave portion is shown in FIGS.
　FIG. 13(A) shows the lap joint member 1A in the case where the inner bottom portion of the cutout recess 24U is located at a depth exceeding the line X connecting the inner end portions of the holes formed in the joint portion SP. 13B shows the lap joint member 1B in the case where the inner bottom portion is located at a depth corresponding to a line Y connecting the centers of the holes formed in the joint portion SP.
　FIG. 13C shows a lap joint member 1C in the case where the inner bottom portion of the cutout recess 24U is located midway between the line Y and a line Z connecting the outer ends of the holes formed in the joint SP. 13D, the width of the entire lap joint member (width of the member in the direction perpendicular to the direction in which tensile stress is generated (arrow F)) is not sufficient, and the inner bottom portion is the line The lap joint member 1D when it is located closer to the flange end 24C than Z is shown.
[0047]
　In the example shown in FIG. 13, the adjacent notch recesses have the same depth, but the adjacent notch recesses may have different depths.
　An example in which the depths of the cutout recesses are different is shown in FIGS. 14(A) to 14(C).
[0048]
　FIG. 14(A) shows the lap joint member 1E in the case where the notched recesses of FIG. 13(A) and the notched recesses of FIG. 13(B) are mixed. That is, a plurality of flange pieces 25 are formed along the longitudinal direction of the lap joint member 1E, and the space between the adjacent flange pieces 25 and 25 corresponds to (A) of FIG. The cutout recesses 251U and the cutout recesses 252U corresponding to FIG. 13B are alternately formed.
[0049]
　FIG. 14B shows a mixture of the notched recesses having an intermediate depth between the notched recesses of FIGS. 13A and 13B and the notched recesses of FIG. 13B. The lap joint member 1F in the case of being shown is shown. That is, a plurality of flange pieces 26 are formed along the longitudinal direction of the lap joint member 1F, and a notch having a depth corresponding to the line X is provided between the flange pieces 26 and the flange pieces 26 that are adjacently arranged. The recesses 261U and the notch recesses 262U corresponding to FIG. 13B are alternately formed.
[0050]
　FIG. 14(C) shows the lap joint member 1G in the case where (A) and (B) of FIG. 14 are combined. That is, a plurality of flange pieces are formed along the longitudinal direction of the lap joining member 1G, and a notch corresponding to (A) of FIG. 13 is provided between the adjacent flange pieces 281 and 282. A recessed portion 281U is formed, a notch recessed portion 282U having a depth corresponding to the line X is formed between the flange piece 282 and the flange piece 283 which are arranged adjacent to each other, and between the flange piece 283 and the flange piece 284, A cutout recess 283U corresponding to FIG. 13B is formed.
[0051]

　Hereinafter, with reference to FIGS. 15 to 18, the lap joint structure (comprising a plurality of metal plate members) of the present invention described above is used for a monocoque body that constitutes an automobile body. An example of application to an important member (vehicle part) that protects an occupant in a cabin when a side collision occurs will be described.
[0052]
[First Application Example]
　This is an example in which the lap joint structure of the present invention is applied to a B pillar 3 of an automobile body structure, and FIG. 15A is a perspective view showing the B pillar. (B) shows a diagram obtained by enlarging the range indicated by the chain double-dashed line B in (A). Note that, in FIG. 15B, the outer panel arranged outside is omitted.
[0053]
　As shown in FIG. 15(A), the B pillar (lap joint member) 3 has, for example, an inner reinforcement (first structural member) 310 extending in the height direction of the vehicle body and a substantially hat-shaped cross section. An outer reinforce (second structural member) 320 is provided, and an outer panel (not shown) is provided on the outer side thereof. Further, the outer reinforce 320 and the outer panel are provided on the flange portion 311 of the inner reinforce 310, for example, Three sheets are superposed and connected by a joining portion SP formed by a mechanical joining means such as a self-piercing rivet. In addition, an adhesive may be used together for dispersion of strain in the overlapping surface of the outer panel and the outer reinforcement and in the joining of the outer reinforcement and the inner reinforcement. Particularly when the outer panel is made of aluminum, it is preferable to use an adhesive together.
　As shown in FIG. 15B, the outer reinforcement 320 includes a plurality of flange pieces 322 and a connecting portion 322A that connects the adjacent flange pieces 322, and a cutout is provided between the adjacent flange pieces 322. A recess 322U is formed. The inner bottom of the notch recess 322U is formed to a position inside the joint SP.
[0054]
　Further, one or both of the inner reinforcement 310 and the outer reinforcement 320 is, for example, a steel plate member obtained by cold press forming a high-strength steel plate (for example, a high-strength steel plate having a tensile strength of 590 MPa or more), or It is a hot stamp material (for example, a steel sheet member having a tensile strength of 1200 MPa or more) in which a martensite structure is formed by forming a steel sheet for hot stamp material by hot stamping. Further, the outer panel provided on the outer side of the outer reinforcement is a member formed by molding a similar steel plate or aluminum plate.
　The arrow F in FIG. 15 indicates the direction of the tensile stress (assumed tensile stress) generated when the B pillar 3 receives an external force due to a collision or the like. When an automobile structural member (automotive component) receives an external force in the bending direction due to a collision, the stress generated by the collision acts on the automobile structural member (automotive component) in a direction connecting the inside and outside of the cabin. However, the tensile stress generally occurs in the direction along the longitudinal direction.
[0055]

　This example is an example in which the lap joint structure of the present invention is applied to an automobile structural member (automobile component) including the roof rail 4, and FIG. 16A is a perspective view showing the roof rail 4. 16B is an enlarged view of the range indicated by the alternate long and two short dashes line B in FIG. 16A through the outer panel, and FIG. 16C shows FIG. The figure which expanded the range shown by the dashed-two dotted line C in (A) of is shown.
[0056]
　As shown in (A) of FIG. 16, the roof rail (lap joint member) 4 extends along, for example, the length direction of the vehicle body, is connected to the A pillar, and has a height from the center in the length direction. And is connected to the B pillar.
　The roof rail (lap joint member) 4 includes an inner reinforcement (first structural member) 410, an outer reinforcement (second structural member) 420 having a substantially hat-shaped cross section, and an outer panel (not shown) outside thereof. Further, the outer reinforcement 420 and the outer panel are connected to the flange portion 411 of the inner reinforcement 410 by, for example, a joint portion SP formed by a mechanical joint means. In addition, an adhesive may be used together in the overlapping surface of the outer panel and the outer reinforcement and in the joining of the outer reinforcement and the inner reinforcement. Particularly when the outer panel is made of aluminum, it is preferable to use an adhesive together.
[0057]
　As shown in FIGS. 16B and 16C, the outer reinforcement member 420 includes a plurality of flange pieces 422 formed along the roof rail 4, a connecting portion 422A for connecting the adjacent flange pieces 422, and B. A plurality of flange pieces 424 formed along the pillar and a connecting portion 424A connecting the adjacent flange pieces 424 are provided, and a cutout recess 422U is formed between the adjacent flange pieces 422 and is adjacent to each other. A notch recess 424U is formed between the flange pieces 424.
[0058]
　Further, either one or both of the inner reinforcement 410 and the outer reinforcement 420 are made of a steel plate member or a hot stamp material similar to the first application example. Further, the outer panel is a member formed by molding a steel plate or an aluminum plate.
　The arrow F in FIG. 16B indicates the direction of the tensile stress (assumed tensile stress) generated when the roof rail 4 receives an external force due to a side collision or the like, and the arrow F in FIG. The direction of tensile stress (assumed tensile stress) generated when the B pillar receives an external force due to a collision or the like is shown.
[0059]

　This example is an example in which the lap joint structure of the present invention is applied to a bumper (automobile structural member, automobile part) 5, and FIG. 17A is a perspective view showing the bumper. 17B shows an enlarged view of the range indicated by the chain double-dashed line B in FIG. 17B.
[0060]
　As shown in FIG. 17A, the bumper (lap joint member) 5 is formed to extend along the width direction of the vehicle body, and includes a bumper inner reinforcement (first structural member) 510, A bumper outer reinforcement (second structural member) 520 having a hat-shaped cross section in which a notch recess is formed, and further, the bumper outer reinforcement 520 is joined to the flange 511 of the bumper inner reinforcement 510 by, for example, mechanical joining means. It is connected by the section SP.
[0061]
　As shown in (B) of FIG. 17, the bumper outer reinforcement 520 includes a plurality of flange pieces 522 formed along the flange 511 of the bumper inner reinforcement 510 and a connecting portion 522A connecting adjacent flange pieces 522. A notched recess 522U is formed between the adjacent flange pieces 522.
[0062]
　One or both of the bumper inner reinforcement 510 and the bumper outer reinforcement 520 are made of a steel plate member or a hot stamp material similar to those in the first application example.
　The arrow F in FIG. 17B indicates the direction of tensile stress (assumed tensile stress) generated when the bumper 5 receives an external force due to a collision or the like.
[0063]

　This example shows an example in which the lap joint structure of the present invention is applied to an automobile B-pillar outer reinforcement 6, and FIG. 18A is a perspective view showing the B-pillar outer reinforcement. 18B is a vertical cross-sectional view taken along line XVIB-XVIB in FIG. 18A, and FIG. 18C is a vertical cross-sectional view taken along line XVIC-XVIC in FIG. 18C. It is a side view.
[0064]
　A reinforcing member 620 having a groove-shaped cross section is arranged inside the B pillar outer reinforcement 610 having a hat-shaped cross section, and the wall surfaces of the two members are connected by, for example, a joint portion SP formed by mechanical joining means. The end portion of the side wall 621 of the reinforcing member 620 is located in the middle of the rising wall 611 of the B pillar outer reinforce 610.
　The side wall 621 of the reinforcing member 620 is provided with a cutout recess 622U, and is provided with a plurality of side wall pieces 622 and a connecting portion 622A connecting adjacent side wall pieces 622, and between the adjacent side wall pieces 622. A notch recess 622U is formed.
[0065]
　Either one or both of the B pillar outer reinforcement 610 and the reinforcing member 620 is a steel plate member or a hot stamp material similar to the first application example.
　The arrow F in FIG. 18A indicates the direction of the tensile stress (assumed tensile stress) that occurs when the B pillar receives an external force due to a collision or the like.
[0066]
　By applying the lap joint structure of the present invention to automobile structural members (vehicle components) arranged around the cabin as shown in FIGS. 15 to 18, these structural members are joined by mechanical joining means. It is possible to suppress breakage due to the hole of the portion SP, and it is possible to enhance safety against side collision.
[0067]
　It should be noted that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the invention.
　For example, in the above embodiment, the case where the present invention is applied to automobile parts has been described, but for example, in fittings for construction, beams, link members, simple warehouses, furniture, furniture, etc., the overlapping part is machined. The present invention can be applied to various lap joint members joined by a dynamic joining means.
[0068]
　Further, for example, in the above-described embodiment, a case has been mainly described in which a high-strength steel sheet having a tensile strength of 590 MPa or more is described, but the present invention is also applied to a steel sheet having a tensile strength of less than 590 MPa, for example. be able to. Further, it is similarly applicable to a member in which aluminum materials are joined together or a member in which aluminum material and iron material are joined together.
[0069]
　In the above-mentioned embodiment, the case has been described in which the joining portion is formed in the overlapping portion where two or three plate members are overlapped to form the lap joint structure, but four or more plate members are overlapped. It may be applied to a lap joint structure.
[0070]
　Further, in the above embodiment, the case where one plate member or two plate members out of the two or three plate members is provided with the notch concave portion is described, but for example, four or more ( It is also possible to form a lap joint structure by forming a joint part in the lap portion where a plurality of plate members are piled up. In such a case, it is possible to arbitrarily set the number of plate members having the cutout recesses. can do.
[0071]
　Further, in the lap joint structure of the present invention, when a lap joint structure is formed by forming a joint portion in a lap portion where three or more (plurality) plate members are piled up (for example, three plate members are piled up). When a joining portion is formed in the overlapped portion to form a lap joint structure), a notch recess may be formed in one plate member on the center side in the plate thickness direction, or one notch on the center side may be formed. It is also possible to form the cutout recesses in the plate members on both sides (outside) in the plate thickness direction without forming the cutout recesses in the plate member. Needless to say, the lap joint structure of the present invention may be applied to the case of four or more plate members.
[0072]
　Further, in the present invention, in the overlapping portion formed by overlapping the plate member, without using a flange portion, for the purpose of partial reinforcement or the like, when the plate members are overlapped and joined without depending on the flange or the flange Needless to say, this includes the case of joining to the press-formed shape part.
Example 1
[0073]
　The test No. of FIG. Tensile test pieces before the tensile test shown in 1 to 5 were prepared.
　For each tensile test piece, a plate A having a tensile strength of 980 MPa and having a constricted central portion, and a plate B having a tensile strength of 590 MPa and having the same shape as the plate A were used.
　Test No. Test Nos. 1 to 3 are examples of joining using blind rivets. Test No. 1 is an example in which the plate A and the plate B are overlapped and joined without forming a cutout recess. No. 2 is an example in which a notch concave portion is provided at the same position of both plates and they are joined to each other. No. 3 is an example in which the plate A (upper steel plate) made of a high-strength steel plate is provided with the notch recesses and joined.
　Test No. Nos. 4 and 5 are examples in which a plate A and a plate B are joined using a self-piercing rivet (SPR), and a hole is formed only in one steel plate. No. 4 is an example in which notch recesses are not provided, and test No. 5 is an example in which a notched concave portion is provided in the upper plate A having a hole.
　FIG. 19 shows the state of each test piece before the tensile test, and Table 1 shows the test conditions collectively. The hole diameter by the rivet was 4 mm, and the shortest distance from the end of the hole to the end of the test piece was 8 mm.
[0074]
　Next, each test piece was subjected to a tensile tester, and the strain until breakage (breaking strain (%)) was measured. In the tensile test, the distance between scores was 50 mm and the tensile speed was constant at 3 mm/min.
　The state of breakage of the test piece is shown in FIG. 4, and the test results are shown in Table 1.
　In the present invention example in which the test piece was provided with a notched recess, the test piece was fractured starting from the vicinity of the corner of the recessed portion, whereas in the comparative example in which the notched recess was not provided in the test piece, the edge of the hole It was fractured from the starting point, and the result was that the fracture strain of the example of the present invention was greatly improved as compared with the comparative example.
[0075]
[table 1]

Example 2
[0076]
　For the tensile test piece, as in Example 1, a steel plate having a tensile strength of 980 MPa was used, and a plate C having a notched concave portion in part, and a plate D using an Al plate having a strength of 275 MPa or a steel plate of 590 MPa were used. Was prepared, and the plate C and the plate D were piled up in the combinations shown in Table 2 to prepare tensile test pieces.
　Test No. In Nos. 6 and 7, as in the case of Example 1, an example in which self-piercing rivets (SPR) were joined in a simulated form, Test No. 8 and 9 are examples in which the plate C and the plate D are joined by friction stir spot joining.
　The results of tensile test of each test piece as in Example 1 are shown in Table 2. The same results as in Example 1 were obtained depending on the presence or absence of the notched recesses in the test piece.
[0077]
[Table 2]

Industrial availability
[0078]
　According to the lap joint structure according to the present invention, it is possible to prevent the joint portion of the lap portion by the non-melting joint means from breaking from the hole of the joint portion as a starting point, and thus it is industrially applicable.
Explanation of symbols
[0079]
　SP Joining part (joint part) by non-melt joining means
　MJ Mechanical joining means
　1, 7 Lap joint member
　3 B pillar (lap joint member, automobile part)
　4 Roof rail (lap joint member, automobile part)
　5 Bumper (lap joint member) , Automobile parts)
　6 B pillar outer 　reinforcement (lap joint member, automobile parts)
　10 plate-shaped member (plate member)
　11 flange portion of plate-shaped member 20,
710, 720 hat-shaped member, first hat-shaped member, second Hat-shaped members
　21, 711, 721 Standing wall portions
　22
　, 24, 25, 26, 271, 272, 281, 282, 283, 284, 712, 722 Flange pieces (flange) 22A, 24A, 251A, 252A, 261A, 262A, 27A, 281A, 282A, 283A, 712A, 722A Connection part
　22U, 24U, 251U, 252U, 261U, 262U, 27U, 281U, 282U, 283U, 712U, 722U Notch recess
　22B, 24B, 722B Standing wall part Bending starting points
　22C and 24C of the side flange end portion The outer end portion of the flange (the end portion of the overlapping portion)
　30 The hole through which the mechanical joining means is inserted
　310 Inner 　reinforce
　( first structural member) 320 Outer
reinforce (second structural member) 322
　, 422, 424, 522, 622 Flange piece, side wall piece 322A, 422A, 424A, 522A, 622A Connecting portion
　322U, 422U, 424U 522U, 622U Notched recess
　410 Inner reinforce (first structural member)
　420 Outer
　reinforce (second structural member) 510 Bumper inner reinforce
　520 Bumper outer reinforce
　610 B pillar outer
　reinforce 620 Reinforcement member
The scope of the claims
[Claim 1]
　The lapped portions of the plurality of plate members are point-shaped joined by mechanical joining means or friction stir spot joining means at the plurality of joining portions, and the joining portion is mechanically joined by at least one plate member. In the lap joint structure in which there is a hole through which is inserted, or a hole formed at the time of spot joining by the friction stir spot joining means
　, the lap portion of at least one of the plate members is adjacent to the lap portion. A notch recess is formed in the joint direction from the end of the overlapping portion between the joining portions, and
　an inner bottom portion of the notching recess has an end portion of the overlapping portion when the inner diameter of the hole is K. To K or more deep positions, a lap joint structure characterized by being formed.
[Claim 2]
　The distance L between the end portion of the hole and the end portion of the plate member in which the cutout recess is formed satisfies the relationship of L≧0.8K with respect to the inner diameter K of the hole. The lap joint structure according to claim 1, wherein the lap joint structure is located.
[Claim 3]
　The lap joint structure according to claim 1 or 2, wherein the hole is a through hole that penetrates the at least one plate member.
[Claim 4]
　The lap joint structure according to any one of claims 1 to 3, wherein the shortest distance between the end of the hole and the end of the cutout recess is 0.8K or more.
[Claim 5]
　The lap joint structure according to any one of claims 1 to 4, wherein the cutout recess is formed in a plate member having at least the hole.
[Claim 6]
　The lap joint according to any one of claims 1 to 5, characterized in that an inner bottom portion of the cutout recess is formed so as to enter up to a range of 1.5K or more from an end portion of the lap portion. Construction.
[Claim 7]
　The lap joint structure according to any one of claims 1 to 6, wherein an inner bottom portion of the cutout recess portion has a parallel portion that is parallel to an end portion of the overlap portion.
[Claim 8]
　The lap joint structure according to claim 7, wherein a length of the parallel portion is 0.5K or more.
[Claim 9]
　The plate member in which the cutout concave portion is formed is a hat-shaped member having a hat-shaped cross section in which a bent portion is formed on the opposite side of the end portion of the overlapping portion with the joint portion interposed therebetween, and the cutout concave portion is The lap joint structure according to any one of claims 1 to 8, wherein the lap-shaped member is formed in a range closer to the end portion than the bent portion of the hat-shaped member.
[Claim 10]
　The lap joint according to any one of claims 1 to 9, wherein the plate member is a steel plate member, and the notch recess is formed in a steel plate member having a tensile strength of 590 MPa or more. Construction.
[Claim 11]
　The lap joint structure according to any one of claims 1 to 10, wherein the mechanical joining means is any one of a blind rivet, a self-piercing rivet, a drill screw, a bolt, and a resistance element welding.
[Claim 12]
　The lap joint structure according to any one of claims 1 to 11, characterized in that in addition to the joint by the mechanical joint means or the friction stir spot joint means, joint by resin is also used.