Technical field
[0001]
　The present invention relates to a structural member and the vehicle structural member using the same have the impact resistance.
BACKGROUND
[0002]
　Structural member in cross-section has a hat member hat shape, a tubular portion formed by the closing plate to be bonded to the hat member is used in a variety of applications. Applications include for example, vehicles, buildings, and a structural member of the large containers. Particularly structural members used in automobiles, impact resistance is required.
[0003]
　For example, International Publication No. 2005/058624 (Patent Document 1), for the impact, the metal tube which is mounted in the structure of both ends supported on the vehicle body of an automobile is disclosed. The metal tube has a bend in full or partially. Is arranged to the outer peripheral side of the bent portion is substantially matches the direction of impact applied to the vehicle body. The metal pipe, compared with a reinforcing member using a straight tube, having excellent impact resistance for the body reinforcement.
CITATION
Patent Document
[0004]
Patent Document 1: WO 2005/058624
Summary of the Invention
Problems that the Invention is to Solve
[0005]
　Structural member having a tubular portion, bent and shock exceeding yield strength, bending portion protrudes. When thinning the structural member for weight reduction, the protruding degree tends to be large when broken by an impact. For example, structural members used in automobiles, it is preferable degree of projection inward when subjected to impact from the outside of the vehicle is small. Thus, in the structural member, the degree to which the portion deformed by the impact caused by the collision protruding, it may be preferable smaller.
[0006]
　Accordingly, the present application discloses a structural member and the vehicle structural member using the same protruding degree during deformation due to an impact can be further reduced.
Means for Solving the Problems
[0007]
　Structural member according to one aspect of the present invention comprises at least one closing plate, and a hat member. The hat member includes a top wall, and two first ridgeline on the both ends of the top wall, and two flanges, each being joined to the closing plate, two at the ends of the two flanges a second ridge, between said two first edges and said two second edges, and two side walls positioned respectively. The length of the extending direction of the length of said first ridge line of the tubular section which is formed by the hat member and the closing plate, the longer of the length of the two side walls in a direction perpendicular to the top wall H is 6 times more. Each of said two side walls comprises a high strength portion and a low strength portion. The high strength portion, the to opposed portions of the two side walls, the extending direction of the first ridge is formed over three times the distance 2/3 times of the H. Yield strength of the high strength portion is not less than 500 MPa. The low strength portion is arranged on both sides extending direction of said first ridge line of the high-strength portion. Yield strength of the low strength portion is 60 to 85% of the high intensity part.
Effect of the invention
[0008]
　According to the present disclosure can provide a structural member and the vehicle structural member using the same protruding degree during deformation due to an impact can be further reduced.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009]
[Figure 1A] at both ends is a diagram illustrating a configuration example of the supported structural member.
It is a diagram illustrating a deformation behavior example of the structure member shown in FIG. 1B] FIG 1A.
It is a diagram showing another deformation behavior example of the structure member shown in FIG. 1C] FIG 1A.
Is a perspective view showing the configuration of the structural member in FIG 2A] present embodiment.
The structural member shown in FIG. 2B] FIG. 2A is a side view as viewed from the y direction.
The structural member shown in FIG. 2C] FIG 2A is a side view from the x-direction.
3 is a diagram for explaining the deformation behavior of the structural members having a uniform intensity distribution.
4 is a diagram for explaining the deformation behavior of the structural member having a low strength portion sandwiching the high-strength portion.
The structural member shown in FIG. 5A] FIG. 2A is a top view showing the configuration seen from the z-direction.
It is a diagram illustrating a modification of the arrangement of the high-strength portion and a low strength portion of the structural member shown in FIG. 5B] FIG 2A.
It is a diagram illustrating a modification of the arrangement of the low-strength portion of the structural member shown in FIG. 6A] FIG 2A.
Is a diagram illustrating a modification of the arrangement of the low-strength portion of the structural member shown in FIG. 6B] FIG 2A.
It is a diagram illustrating a modification of the arrangement of the low-strength portion of the structural member shown in FIG. 6C] FIG 2A.
It is a diagram illustrating a modification of the arrangement of the low-strength portion of the structural member shown in FIG 6D] FIG 2A.
It is a sectional view showing a modified example of the cross-sectional shape of FIG. 7A] structural member.
Is a cross-sectional view showing another modified example of the cross-sectional shape of FIG. 7B] structural member.
8 is a diagram for explaining a height direction of the side wall.
Is a sectional view showing a modified example of FIG. 9A] structural member.
Is a cross-sectional view showing another modified example of FIG. 9B] structural member.
It is a sectional view showing still another modification of FIG 9C] structural member.
Is a top view of the structural member as seen from the z direction shown in FIG. 9D] FIG 9B.
Is a side view showing an example of FIG. 10A] curved structural member.
Is a side view showing an example of FIG. 10B] curved structural member.
Is a side view showing an example of FIG. 10C] curved structural member.
Is a side view showing an example of FIG. 10D] curved structural member.
11 is a diagram showing an example of a structure member disposed on the vehicle.
Is a diagram showing an example of the distribution of yield strength of the portion of the structural member including a boundary of FIG. 12 lower strength portion and the high strength portion.
Is a diagram showing a configuration of an analysis model in FIG. 13A] simulation.
It is a diagram showing a configuration of an analysis model in FIG. 13B] simulation.
Is a diagram showing a configuration of an analysis model in FIG. @ 13 C] simulation.
Is a diagram showing FIG. 14 simulation result of deformation of the structural member.
[Figure 15A] Figure 15A is a graph showing a simulation result of the impactor stroke when folding occurs.
[FIG. 15B] FIG. 15B is a graph showing a simulation result of the impactor stroke when folding occurs.
[16] in the case of changing the intensity ratio of the low-strength portion and the high strength portion enter the impact load is a graph showing the amount of deformation due to bending deformation.
Is a graph showing FIG. 17 impactor simulation stroke results.
DESCRIPTION OF THE INVENTION
[0010]
　Inventor cross section member hat-shaped (hereinafter, referred to as the hat member) and were examined for the behavior to impact of the structural member having a closing plate is joined to the hat member, in a tubular portion formed. For example, as shown in FIG. 1A, the structural member 5 is formed to extend in the longitudinal direction of the tubular portion. Structural member 5, in a state in which the longitudinal end portions of the tubular portion is supported, the structure (e.g., a vehicle, a building or container, etc.) often constitutes a part of. Therefore, the inventors examined the behavior to impact of structural members having both ends supported. As a result, with respect to dimension exerted impact of structural members, when the longitudinal dimension of the tubular portion of the structural member (length) of more than about 6 times, the situation where the degree of deformation due to impact is increased occurs it was found.
[0011]
　For example, both ends when an impact is exerted on the longitudinal center of the support structure member 5 into two support portions 32 (y1 in FIG. 1A), the structural member 5, early break with deformation after an impact is applied (see FIG. 1B). Even when an impact is applied to a position between the longitudinal center and one of the support portions 32 of the structural member 5 (y2 in Fig. 1A), the structural member 5 is deformed (see FIG. 1C). Person when impact is applied in the longitudinal center (y1) of the structural member 5, than if the impact is applied to y2, degree of projection premature bending deformation increases. As a result of the analysis, when the both end portions is applied impact the longitudinal center of the structural member 5 supported, it was found that most moment load is high.
[0012]
　The inventors have, by increasing the strength of structural members, was investigated to reduce the degree of deformation of the structural member due to impact. However, it is difficult to reduce the protruding degree by deformation by increasing the strength of the structural member. This is because, although less likely to be deformed against impact increasing the strength of the structural member, degree of projection when deformed by an impact is because not much. Therefore, the inventors, by varying the intensity distribution of the structural member, and further studied to suppress the bending deformation.
[0013]
　Inventors, for material strength and intensity distribution of the structural member, a result of intensive studies, the side walls of the structural member, the more low strength other part low strength portion, and conceived a configuration that arranged in the longitudinal direction. That, and conceived a configuration to place a low low-strength portion in strength than the high strength portion on both sides of the high-strength portion. In other words, it is configured to sandwich the high-strength portion in the low intensity portion in the longitudinal direction of the structural member. In this configuration, load due to applied impact the high strength portion is transmitted to the low-strength portion, bending deformation was found that suppressed. As a result of further trial and error, the intensity of the high-strength portion, the strength ratio high-strength portion of the low-strength portion, by appropriately setting the longitudinal dimension of the high-strength portion, the deformation degree due to impact against the high-strength portion found that can be effectively reduced. Based on this finding, and conceived the structural member of the following embodiments.
[0014]
　(Structure 1)
　structural member of the structure 1 in an embodiment of the present invention comprises at least one closing plate, and a hat member. The hat member includes a top wall, and two first ridgeline on the both ends of the top wall, and two flanges, each being joined to the closing plate, two at the ends of the two flanges a second ridge, between said two first edges and said two second edges, and two side walls positioned respectively. The length of the extending direction of the length of said first ridge line of the tubular section which is formed by the hat member and the closing plate, the longer of the length of the two side walls in a direction perpendicular to the top wall H is 6 times more. Each of said two side walls comprises a high strength portion and a low strength portion. The high strength portion, the to opposed portions of the two side walls, the extending direction of the first ridge is formed over three times the distance 2/3 times of the H. Yield strength of the high strength portion is not less than 500 MPa. The low strength portion is arranged on both sides extending direction of said first ridge line of the high-strength portion. Yield strength of the low strength portion is 60 to 85% of the high intensity part.
[0015]
　In the above structure 1, the length H of the side wall in a direction perpendicular to the top wall is defined by the distance between the first ridge and the second ridge line of each side wall in a direction perpendicular to the top wall and the longer length of the length. Incidentally, two flanges extend in a direction away from each other from the respective second ridge. Further, the direction perpendicular to the top wall, the direction perpendicular to the surface of the top wall, i.e., a vertical direction of the top surface. Structural members of the structure 1 is smaller degree of deformation with respect to an impact applied from the top surface of the hat member.
[0016]
　(Structure 2)
　structural members of the structure 2 in an embodiment of the present invention comprises at least one closing plate, and a hat member. The hat member includes a top wall, and two first ridgeline on the both ends of the top wall, and two flanges, each being joined to the closing plate, two at the ends of the two flanges a second ridge, between said two first edges and said two second edges, and two side walls positioned respectively. The length of the extending direction of the length of said first ridge line of the tubular section which is formed by the hat member and the closing plate, the longer of the length of the two side walls in a direction perpendicular to the closing plate H is 6 times more. Each of said two side walls comprises a high strength portion and a low strength portion. The high strength portion, the to opposed portions of the two side walls, the extending direction of the first ridge is formed over three times the distance 2/3 times of the H. Yield strength of the high strength portion is not less than 500 MPa. The low strength portion is arranged on both sides extending direction of said first ridge line of the high-strength portion. Yield strength of the low strength portion is 60 to 85% of the high intensity part.
[0017]
　In the above structure 2, the length H of the side wall in a direction perpendicular to the closing plate, is defined as a distance between the first ridge and the second ridge line of each side wall in a direction perpendicular to the closing plate and the longer length of the length. Incidentally, two flanges extend in a direction away from each other from the respective second ridge. Further, the direction perpendicular to the closing plate is perpendicular to the surface of the closing plate. Structure The structure of the two members has a smaller degree of deformation with respect to an impact applied from the closing plate.
[0018]
　(Structure 3)
　structural members of the structure 3 in an embodiment of the present invention comprises at least one closing plate, and a channel member. It said channel member, said a top wall, and two first ridgeline on the both ends of the top wall, and two junctions each of which is joined to the closing plate, said two first edges and between the two junctions, and two side walls positioned respectively. The extending direction of the length of said first ridge line of the tubular section which is formed by said closing plate and the channel member is, in a direction perpendicular to the top wall, the length of the longer of the length of each side wall it is 6 times or more of the H. Each of said two side walls comprises a high strength portion and a low strength portion. The high strength portion is in opposed portions of the two side walls, the first extending direction of ridge lines, the formed over a length 3 times the distance 2/3 times more H. Yield strength of the high strength portion is not less than 500 MPa, the low strength portions are arranged on both sides extending direction of said first ridge line of the high-strength portion. Yield strength of the low strength portion is 60 to 85% of the high intensity part.
[0019]
　In the above structure 3, the length H of the side wall in a direction perpendicular to said top wall includes a first ridgeline of each side wall in a direction perpendicular to said top surface, extending the junction of the first ridge line of the length defined by the distance between the bonding lines defined by connecting in a direction to the longer length of the. Structural members of the structure 3, point flange no different from the structure 1. That is, the hat material structure 1 is channel-shaped member in the structure 3. Similar to the structural member structural member also of the structure 1 of the structure 3, is small deformation degree against shock applied from the top surface of the channel material.
[0020]
　(Structure 4)
　structural members of the structure 4 in the embodiment of the present invention comprises at least one closing plate, and a channel member. The channel member has one top wall, and two first ridgeline on the both ends of the top wall, a flange joined to the closing plate, one second at the end of the flange the lies between the ridge line, a first side wall located between said first ridge and said second ridge line, and a joint portion which is joined to the closing plate, said first ridge and said junction and a second sidewall. The extending direction of the length of said first ridge line of the tubular section which is formed by said closing plate and the channel member, the said in a direction perpendicular to the top surface of the first side wall length or the second of the length of the side wall is at least 6 times longer length H. It said first side wall comprises a high strength portion and a low strength portion. Wherein said high-strength portion of the first side wall, said second side wall portion opposite to, in the extending direction of the first ridge of the tubular portion, the 3 times or less of 2/3 or more H distance is formed over. Yield strength of the high strength portion is not less than 500 MPa. The low strength portion is arranged on both sides extending direction of said first ridge line of the high-strength portion. Yield strength of the low strength portion is 60 to 85% of the high intensity part. It said second sidewall includes a high strength portion and a low strength portion. Wherein said high-strength portion of the second sidewall, the first sidewall and the facing portion, the extending direction of the first ridge of the tubular portion, 3 times 2/3 times the length H It is formed over the following distances. Yield strength of the high strength portion is not less than 500 MPa. The low intensity portion. They are arranged on both sides extending direction of said first ridge line of the high-strength portion. Yield strength of the low strength portion is 60 to 85% of the high intensity part.
[0021]
　In the above structure 4, the length H is the length defined by the distance between the first ridge and the second ridge line of the first side wall in a direction perpendicular to said top surface, perpendicular to the top wall a bonding wire to the bonding portion of the second side wall in the direction defined by connecting the extending direction of the first ridge that, in the longer of the length defined by the distance between the first ridge line is there. Structural members of the structure 4 is a modification of the structure 3. Structure 3 with respect to the flange is not in the both ends of the channel member, the structure 4 is different that the end portion of the one there is a flange. Structural members of the structure 4, similarly to the structure 1 and structure 3, a small degree of deformation with respect to an impact applied from the top surface of the channel material.
[0022]
　According to the above structure 1-4, the deformation due to the load due to impact of the high-strength portion, early, it can be dispersed in the low intensity portion. As a result, it is possible to suppress the bending deformation of the structural member due to impact. In the above structure 1, 3 and 4, when an impact is applied to the top wall, the deformation of the more structural members can be suppressed. In the above structure 2, when an impact is applied to the closing plate, the deformation of the more structural members can be suppressed.
[0023]
　In the above structure 1-4, the length H is the height of the side wall. In structure 1,3,4, and the height direction of the side wall and a direction perpendicular to the top wall. In structure 2, a direction perpendicular to the closing plate and the height direction of the side wall.
[0024]
　(Structure 5)
　Next structure 5 will be described. In any of the above structures 1-4, a length in the extending direction of the first edge line of the low-strength portion is preferably the or less and 2 times 3/5 times the length H. This further makes it possible to further suppress the deformation degree of the shock due to the structural member to high-strength portion.
[0025]
　(Structure 6)
　Next structure 6 will be described. In any of the above structures 1-5, wherein said high-strength portion between the low-strength portion is preferably arranged at the center in the extending direction of the first ridge in said tubular portion. The first extending direction of the central ridge of the tubular portion, the moment due to the impact tends to increase. Like the structure 5, the high-strength portion is disposed at the center in the extending direction of the first edge line, by arranging the low intensity on both sides, it is possible to suppress efficiently structure deformation due to impact member.
[0026]
　(Structure 7)
　Next structure 7 will be described. In any of the above structures 1, 3 and 4, between the opposite side of the other end to one end of said first ridge line side of the side wall and the first edge line, the other end from the one end of the side wall towards, the region between said one end of said side wall to 1/4 position of the length to the other end, the there may be an end portion of the one end side of the low-strength portion.
[0027]
　(Structure 8)
　will be described the structure 8. In the above structure 7, toward the one end from the other end of said side wall, in the area to the position of the length of (4/5) between said one end and said other end of said side wall, of the low-strength portion the end of the other end may be positioned. In this case, the length in the direction toward the other end from the one end of the low-strength portion is a length of 1/5 or more between said one end and said other end of said side wall.
[0028]
　(Structure 9)
　Next, the structure 9 will be described. In the above structure 7 or 8, wherein located between the one end and the other end of the side wall adjacent the end of the low-strength portion, the yield stress than the low strength portion may comprise a high region.
[0029]
　(Structure 10)
　and then the structure 10 will be described. In any of the above structures 1, 3 and 4, between the first and one end of the ridge side to the first ridgeline opposite side of the other end of said side wall, toward the other end from the one end , a region between the position of (2/5) of the length between said one end and said other end of said side wall, said one end side of the end portion of the high-strength portion that is between the low-strength portion There may be located. In this case, the other end of said side wall, the end of the other end side of the high-strength portion is located. Over a period from the end of the one end side of the high-strength portion to one end of said side walls, the yield strength is added a low strength portion 60 to 85% of the high-strength portion is provided.
[0030]
　According to the above structure 7-10, it is possible to suppress efficiently the deformation of the structural member against the impact of the top wall.
[0031]
　The structural 7-10 Oite, if the side wall is positioned between the first ridge and the second ridge, the first ridge line becomes one end of the side wall, the second ridge is the other end of the side wall . Therefore, the length between one end and the other end of the side wall, the first ridge and the distance between the second ridge (distance). Sidewall when located between the junction and the first ridge, the first ridge on the other hand becomes end joint line connecting the joint to the extending direction of the first ridge line is the other end. Therefore, the length between one end and the other end of the side wall is defined by the distance between the first edge line and the bonding line (distance).
[0032]
　(Structure 11)
　and then the structure 11 will be described. In the above structure 2, between the other end of the one end and the first edge line side opposite the first ridgeline side of the side wall, toward the other end from the one end of said side wall, said side walls of the in the region between the contrast and the end to 1/4 position of the length between the other end, the there may be an end portion of the one end side of the low-strength portion.
[0033]
　If located between the side wall first ridge and the second ridge, the length between one end and the other end of the side wall, defined by a first ridge and a distance between the second ridge line (distance) It is. If the side wall is positioned between the junction and the first edge line, the length between one end and the other end of the side wall, and the first edge line, connecting the junction to the extending direction of the first ridge line it is defined by the spacing (distance) between the bonding wires.
[0034]
　(Structure 12)
　and then the structure 12 will be described. In the structure 11, toward the one end from the other end of the side wall, the region between said one end of said side wall to a position of (4/5) of the length to the other end, the low intensity end of the other end of the section may be located. In this case, the length in the direction toward the other end from the one end of the low-strength portion is a length of 1/5 or more between said one end and said other end of said side wall.
[0035]
　(Structure 13)
　and then the structure 13 will be described. In the structure 11 or 12, wherein there is between the one end and the other end of the side wall adjacent the end of the low-strength portion, the yield stress than the low strength portion may comprise a high region.
[0036]
　(Structure 14)
　and then the structure 14 will be described. In the above structure 2, between the other end of the one end and the first edge line side opposite the first ridgeline of the side wall, toward the other end from the one end, said one end of said side wall in the region between the position of (2/5) of the length between to said other end from an end portion of the one end side of the high-strength portion that is between the low-strength portion may be positioned . In this case, the other end of said side wall, the end of the other end side of the high-strength portion is located. Over a period from the end of the one end side of the high-strength portion to one end of said side walls, the yield strength is added a low strength portion 60 to 85% of the high-strength portion is provided.
[0037]
　According to the above structure 11-14, it is possible to suppress efficiently the deformation of the structural member against the impact of the closing plate.
[0038]
　The structural 11-14 Oite, if the side wall is positioned between the first ridge and the second ridge, the second ridge becomes one end of the side wall, the first ridge line is the other end of the side wall . Therefore, the length between one end and the other end of the side wall, the first ridge and the distance between the second ridge (distance). Sidewall when located between the first edge line and the junction, the junction becomes the first extending direction connecting it joining line is one end of the ridge, the first ridge line is the other end. Therefore, the length between one end and the other end of the side wall is defined by the distance between the first edge line and the bonding line (distance).
[0039]
　(Structure 15)
　will be described next structure 15. In any of the above structures 1, 3, 4, 7 and 10, the structural member is preferably curved so as to be convex toward the top surface side. Thus, the structural member hardly deformed by impact to the top wall.
[0040]
　(Structure 16)
　Next, the structure 16 will be described. In any of the above structures 2,11 and 14, the structural member is preferably curved so as to be convex toward the closing plate side. Thus, the structural member is less likely to be deformed by impact to the closing plate.
[0041]
　(Structure 17)
　will now be described the structure 17. In any of the above structures 1 to 16, in the cross section of the plane perpendicular to the extending direction of the first ridge, the virtual line segment the closing plate connecting part which is joined to the hat member and the channel member at least in part, it may be a certain aspect between the closing plate and the top wall. In structure 17, the closing plate comprises an intermediate portion between said hat member or the portion overlapped with the pair of superimposed on channel member and the pair of overlapping portions. The intermediate portion is formed to protrude in a direction away from said hat member and the channel member with respect to the overlapping portions.
[0042]
　(Structure 18)
　and then the structure 18 will be described. Structural members of the structure 18 is fitted with one of the structural members of the structure 1 to 17 in a vehicle. In this case, the top wall or the closing plate is the above two coupling portions provided in two places or more away 6H in the extending direction of the first ridge, the two connecting portions to be connected to another member including.
[0043]
　(Structure 19)
　Next, a description will be given of a structure 19. In the structure 18, the high strength portion is preferably arranged at the center between the two connecting portions. Thus, it is possible to suppress efficiently the deformation of the structural member due to impact.
[0044]
　[Embodiment]
　FIG. 2A is a perspective view showing the configuration of a structural member 10 in this embodiment. Figure 2B is a side view of the structural member 10 shown in FIG. 2A in the longitudinal direction (y-direction). Figure 2C is a side view of the structural member 10 shown in FIG. 2A the direction perpendicular to the longitudinal direction (x-direction).
[0045]
　Structural member 10 shown in FIGS. 2A ~ 2C are provided with hat member 1 having a hat-shaped cross section, the closing plate 2 which is joined to the hat member 1. Structural member 10 includes a tubular portion formed in a hat member 1 and the closing plate 2. The tubular portion has a space surrounded by a hat member 1 and the closing plate 2 therein. That is, the tubular portion has a closed cross section.
[0046]
　As shown in FIG. 2A, the hat member 1 has a top wall 13, a pair of side walls 11 and 12, a pair of flanges 14. A pair of side walls 11, 12 extending from both ends of the top wall 13, facing each other. A pair of flanges 14, in each pair of side walls 11 and 12, the one end portion of the top wall 13 of the side wall 11, 12 extending from the other end opposite to the opposite direction outside of the pair of side walls 11, 12. Closing plate 2 is provided by bonding a pair of flanges 14.
[0047]
　Boundary between the top wall 13 and a pair of side walls 11, 12 (shoulder) 123, forms the first ridge 123. In this example, the longitudinal direction of the tubular portion is a direction of extension of the first ridge 123, the longitudinal direction and the extending direction of the first ridge 123 of the tubular section may not be the same. Incidentally, the longitudinal direction of the tubular portion, a central axis connecting the center of gravity of the cross section of the tubular portion (axial center). Flange 14 and the boundary portion (shoulder portion) of a pair of side walls 11, 12 124, to form the second ridge 124 extending in the longitudinal direction of the tubular portion. Incidentally, the extending direction of the second ridge 124 may be the same as the longitudinal direction of the tubular portion. In the example shown in FIG. 2A, the longitudinal direction of the tubular portion is y-direction is the same as the longitudinal direction of the structural member 10. In the structural member 10, the dimension in the direction of extension of the edge which is formed at the boundary of the top wall 13 and a pair of side walls 11, 12 (y direction) in the direction (x direction) in which the pair of side walls 11, 12 are opposed to each other It is longer than the dimension. The length LY in the extension Zaikata clause hat member 1 and the closing plate 2 first ridge 123 of the tubular portion formed in is more than 6 times the height H of the side walls 11, 12 i.e. 6H above ( LY ≧ 6H). Note that the extending direction of the first ridge 123, extending direction of the second ridge 124 may be different.
[0048]
　Each of the pair of side walls 11 and 12, provided with high-strength portion 11A, 12A and the low-strength portion 11B, a 12B. High-strength portion 11A, 12A are provided on the mutually opposite portions of the pair of side walls 11, 12. That is, the high-strength portion 11A of the one side wall 11 of the pair of side walls 11 and 12, the high strength portion 12A of the other side wall 12 is provided at a position facing each other. Low strength portions 11B, 12B also, in each of the pair of side walls 11 and 12, is provided in a portion opposed to each other. That is, the low strength portion 11B of one of the side walls 11, the low-strength portion 12B of the other side wall 12 is provided in a portion opposed to each other.
[0049]
　As shown in FIG. 2C, the high strength portion 11A which face each other, the extending direction of the dimension LA of the first ridge 123 of 12A is, (2/3) H or more, 3H less (2H / 3 ≦ LA ≦ 3H ). High-strength portion 11A, the yield strength of 12A is (in the case of tensile strength, 980 MPa) 500 MPa at least. Low strength portions 11B, 12B, the high strength portion 11A, are arranged in the extending direction on both sides of the first ridge 123 of 12A. That is, in the longitudinal direction of the tubular portion, the high strength portion 11A, 12A are disposed sandwiched low strength portion 11B, to 12B. Low strength portions 11B, yield strength 12B is a high-strength portion 11A, 60 ~ 85% of the yield strength of 12A (60% or more 85% or less). The low strength portion 11B, tensile strength 12B likewise, high-strength portion 11A, it is desirable that between 60 to 85% of the tensile strength of 12A. Thus the deformation degree due to impact even when considering the strength increase due to deformation (work hardening) can be further suppressed.
[0050]
　Low strength portions 11B, 12B, in each of the pair of side walls 11 and 12, are paired. That is, in the side wall 11 of one of the pair of side walls, a pair of low-strength portion 11B is provided on both sides of the high-strength portion 11A. In the other side wall 12 of the pair of side walls, a pair of low-strength portion 12B is provided on both sides of the high-strength portion 12A.
[0051]
　High-strength portion 11A, 12A and the low-strength portion 11B, the portion 11C of the side walls 11 and 12 other than 12B, 12C that is, the low strength portion 11B, the outer portion 11C in the extending direction of the first ridge 123 of 12B, 12C surrender strength, low strength portion 11B, higher than 12B. For example, the yield strength of these portions 11C, 12C, the high strength portion 11A, may be the same as 12A. In this example, the low-strength portion 11B, 12B is low yield strength portion than around it.
[0052]
　As shown in FIGS. 2A ~ Figure 2C, the pair of side walls 11, 12 supporting the top wall 13 for receiving the impact load, by arranging the high strength portion 11A, the low-strength portion 11B on both sides of 12A, the 12B, impact load deformation due to the high strength portion 11A, without being concentrated on 12A, can be dispersed in the low intensity portion 11B, 12B. In this case, the high strength portion 11A, the yield strength of 12A, as more (980 MPa in the case of tensile strength) 500 MPa, a low strength portion 11B, the high strength portion 11A of the 11B, the intensity ratio 12A and 60 to 85% with each other opposed high strength portion 11A, the dimension LA of 12A, (2/3) H or more, is set to be lower than or equal 3H, high-strength portion 11A, an impact deformation due to the load due to 12A, early, low-strength portion 11B , it can be distributed to 12B. As a result, it is possible to suppress the bending deformation of the structural member 10 due to the impact. Note that in FIG. 2A ~ Figure 2C, no particular restriction on the distribution of the intensity and strength of the flange 14. This is because the strength of the flange 14 is because not have a particularly large impact on the performance of the structural member 10.
[0053]
　Figure 3 is a diagram for explaining the deformation behavior of the formed structural member 5 hat member and the closing plate of uniform intensity distribution. Figure 4 is a diagram for explaining the deformation behavior of the structural member 10 having a low strength portion 11B, 12B as shown in FIGS. 2A ~ Figure 2C. 3 and 4 show a deformation behavior in the case of colliding the indenter in a direction perpendicular to the longitudinal direction of the tubular portion of the structural member. 3 and 4 illustrate the deformation behavior of the side surfaces of the longitudinal structure viewed from the direction perpendicular to the members of the direction and the tubular portion of the indenter of the collision.
[0054]
　As shown in FIG. 3, the structural member 5 having a uniform intensity distribution, the impact, the deformation generated in the bending deformation origin P, and proceeds to be wedge-shaped in side view. As a result, the structural member 5 is bent so as to protrude sharply bending direction (the direction of the impact). In some cases, the fall is cracked structural member 5.
[0055]
　As shown in FIG. 4, the structural member 10 having on both sides of the high-strength portion 11A low strength portion 11B (the region indicated by dots in FIG. 4), the deformation proceeds from a bending deformation origin P of the high-strength portion 11A to the inside is reached the boundary of the high-strength portion 11A and the low-strength portion 11B, it tends to proceed in relatively low strength transverse direction (longitudinal direction of the structural member 10). Therefore, deformation spreads in the longitudinal direction, deformation degree of the bending direction (the direction of impact) is reduced.
[0056]
　Incidentally, deformation behavior shown in FIGS. 3 and 4 is not limited to the case where collides the indenter to the structural member. For example, when the bending deformation by axial force to compress the structural member in the longitudinal direction and, as a three-point bending test, when added to a direction perpendicular force statically longitudinally pressing the indenter into the structural member bending deformation can be the same deformation behavior. Further, when allowed to collide the indenter top wall of the structural member and, in any case of colliding the indenter closing plate also becomes deformation behavior similar to FIGS.
[0057]
　For example, the structural member 10 may also be used in a state supported at two points spaced longitudinally. In this case, the structural member 10 includes two connecting portions is a portion coupled to the other member. In other words, the structural member 10 is supported on the other member in the connecting portion. Connecting portion may also be referred to as support. Connecting portion, side wall 11 and 12, is provided on at least one top wall 13 and closing plate 2.
[0058]
　The connecting portions, the structural member 10 is fixed to the other member. Connecting portions of the structural member 10, for example, it is joined to another member by fastening members or welding. The connecting portion may be three or more.
[0059]
　Two connecting portions may also be located away 6H above each other in the extending direction of the first ridge 123. That is, the interval KY the two connecting portions may also be more than 6 times the height H of the side walls 11,12 (KY ≧ 6H). In this case, the problem described with reference to FIGS. 1A ~ FIG 1C is similarly occurs. In other words, (in the example of FIG. 2A, the height H of the side wall 11) dimension exerted impact of the structural member relative to the dimensions KY between two connecting portions, of not less than about 6 times (KY ≧ 6H) when a situation where the degree of deformation due to impact increases may occur.
[0060]
　As a countermeasure, high-strength portion 11A, 12A and the low-strength portion 11B, 12B is provided between the two connecting portions. In this configuration, if an impact is applied between the two connection portions, it is possible to reduce the protrusion degree by deformation of the structural member 10.
[0061]
　For example, in the case of using the structural member 10 as a structural member for a vehicle, the structural member 10, it is attached to the vehicle while supporting at least two coupling portions spaced in the longitudinal direction of the tubular portion. At this time, the top wall 13 disposed outside of the vehicle, to place the closing plate 2 inside the vehicle, is attached to the structural member 10 to the vehicle. Alternatively, place the closing plate on the outside of the vehicle, so as to place the top wall 13 to the inside of the vehicle, it is attached to the structural member 10 to the vehicle. This makes it possible to structural member 10, in the event of an impact from outside the vehicle, to reduce the degree of projecting into the interior vehicle broken.
[0062]
　Or without coupling part, in the structural member 10 shown in FIGS. 2A ~ Figure 2C, the high strength portion 11A, the extending direction of the dimension LA of the first ridge 123 of 12A, compared height H of the side walls 11, 12 Te, 2 / 3H or more, and 3H or less (2 / 3H ≦ LA ≦ 3H). This further makes it possible to further suppress the deformation degree due to the impact of the high-strength portion 11A, 12A. Furthermore, the dimension LA H above, (4/3) H is set to be lower than or equal (H ≦ LA ≦ (4/3) H), it can be further suppressed deformation degree due to impact. That is, the high strength portion 11A, the dimension LA in the extending direction of the first ridge 123 of 12A, the (2/3) H or more, preferably, be at least H. The high strength portion 11A, the dimension LA in the extending direction of the first ridge 123 of 12A are, 3H or less, preferably, the (4/3) H or less.
[0063]
　The low strength portion 11B, the extending direction of the dimension LB of the first ridge 123 of 12B, respectively (3/5) H or ((3/5) H ≦ LB) that it is desirable to. Thus, it is possible to further suppress the deformation degree due to the impact of the high-strength portion 11A. Dimension LB of the low strength portion 11B, from the viewpoint of ensuring strength of the structural member 10, it is preferably less than or equal to 2H. More preferably, the dimension LB of the low-strength portion 11B, it is desirable that the H below.
[0064]
　The size LB dimensions LA and the low strength portion of the high-strength portion to the height H of the sidewall, above relationship, i.e., ((2/3) H ≦ LA ≦ 3H), (H ≦ LA ≦ (4 / 3) H) or not limited to the case which satisfies exactly the ((3/5) H ≦ LB, etc.). But also the case that contains the degree of error can be regarded as satisfying the above relationship. Length LY of the structural member 10 to the height H of the side wall is also not limited to the case which satisfies the above relationship (6H ≦ LY) exactly. Approximately 6 times the structural member of the height H of the side wall, regarded as structural members with the above relationship (6D ≦ LY).
[0065]
　Further, in the example shown in FIG. 2A ~ Figure 2C, the boundary of the low-strength portion 11B and the high boundary strength portion 11A and the low-strength portion 12B and the high strength portion 12A are on a plane perpendicular to the longitudinal direction of the tubular portion. Boundary in the form of low-strength portion and the high strength portion is not limited to this. Boundary of the low intensity portion and the high-strength portion may be on a plane perpendicular to the longitudinal direction of the tubular portion. For example, the boundary of the low-strength portion and the high strength portion may be inclined to the longitudinal direction perpendicular to the plane of the tubular portion, or may be meandering. In this case, inclined or lowest strength portion of the position and the highest intensity portion toward a position of close middle of the meander boundary, regarded as the boundary of the low-strength portion and the high strength portion is located. Low strength portion 11B, and an outer portion 11C in the longitudinal direction of the tubular portion of the 12B, the low strength portion 11B, is the same for the boundary between 12B.
[0066]
　Further, in order to meet the challenges described with reference to FIGS. 1A ~ FIG 1C, the high strength portion 11A, easy location bending of structural members 10 and 12A in the extending direction of the first ridge 123, be positioned for example at the center desirable. That is, the high strength portion 11A, at least a portion of 12A is, it is desirable to configure so as to be positioned in the extending direction central portion of the first ridge 123 of the structural member 10. Alternatively, as described above, when connected to another member in a structural member 10 the two connecting portions, the center between the two connecting portions, it is desirable to place high-strength portion 11A, the 12A. That is, the high strength portion 11A, at least a portion of 12A is, it is desirable to configure so as to be positioned in the central portion between the two connecting portions. Thus, in either case with and without coupling part there is also, in the structural member 10, effectively a bending deformation of the largest becomes frangible portion moment due impact (middle point between the member center or connecting portion) it can be suppressed to.
[0067]
　Figure 5A is a top view showing the configuration viewed structural member 10 shown in FIG. 2A from the top (top wall 13, z direction). In Figure 5A, it shows a portion of the side wall 11 and 12 appear to see through top wall 13 by a broken line. To avoid bending and twisting structural member 10, as in the example shown in FIG. 5A, the pair of side walls 11 and 12, the high strength portion 11A which face each other, 12A is opposite of the pair of side walls 11, 12 it is preferably disposed to overlap completely when viewed from the direction (x-direction). That is, the whole high-strength portion 12A in the entire and the other side wall 12 of the high-strength portion 11A of one of the side walls 11 are overlapped when viewed from the opposing direction. Low strength portions 11B which face each other of the pair of side walls 11, 12, 12B are also arranged to completely overlap when viewed from the opposing direction (x-direction). That is, the entire pair of low strength portion 12B in the entire and the other side wall 12 of the pair of low-strength portion 11B of one of the side walls 11 are overlapped when viewed from the opposing direction. In the example shown in FIG. 5A, the opposing direction of the pair of side walls 11 and 12 is perpendicular to the longitudinal direction of the tubular portion (i.e. the central axis Y1).
[0068]
　In Figure 5A, the intensity distribution of one of the side walls 11 of the pair of side walls 11, 12, and the intensity distribution of the other side wall 12, a configuration in which are mirror images of each other. That is, a pair of side walls 11 and 12 of the high-strength portion 11A, 12A and the low-strength portion 11B, 12B are arranged symmetrically with respect to the center virtual surface Y1 of the pair of side walls 11, 12. Accordingly, a possibility that either one resulting in collapse earlier of the pair of side walls 11, 12 is lower. Central imaginary plane Y1 side walls 11 and 12 corresponds to the vertical bisector A of the top surface portion 13 in a cross section perpendicular to the longitudinal direction of the tubular section (see FIG. 2B difference).
[0069]
　For example, FIGS. 2A ~ 2C, in the example shown in FIG. 5A, a pair of side walls 11 and 12 are the same height. The angle between the side wall 11 and top wall 13, the angle between the side wall 12 and top wall 13 is also the same. Therefore, in a cross section perpendicular to the longitudinal direction of the tubular portion, the perpendicular bisector A of the top surface portion 13 as an axis, the cross-sectional shape of the structural member 10 has a symmetrical. Also, the intensity distribution in the cross section of the structural member 10, and has a symmetrical vertical bisector A as an axis. Thus, uneven stress due to impact is reduced.
[0070]
　5B is a diagram showing the high strength portion 11A of the structural member 10 shown in FIG. 2A, 12A and the low-strength portion 11B, a modification of the arrangement of 12B. In the example shown in FIG. 5B, the pair of side walls 11 and 12, the high-strength portion 11A, 12A facing each other, a portion viewed from the opposing direction (x direction) is disposed so as to overlap. Thus, at least a portion of the high-strength portion 11A of one of the side walls 11, and the high strength portion 12A of the other side wall 12, may be disposed so as to overlap when viewed from the opposing direction. Low strength portions 11B which face each other of the pair of side walls 11, 12, 12B also partially viewed from the opposing direction (x direction) is disposed so as to overlap. Thus, at least a portion of the pair of low strength portion 11B of one of the side walls 11, so as to overlap when viewed from a pair of low-strength portion 12B and the opposite direction in the other side wall 12, may be disposed. For Figure 5B, easily it bends obliquely to the top wall 13 is a central imaginary plane Y1. Since the top wall 13 is hardly bent at the shortest distance, the impact absorbed energy increases.
[0071]
　In the example shown in FIGS. 5A and 5B, the dimension LA is in the extending direction of the first ridge 123 of the high-strength portion 11A and the high strength portion 12A which face each other, are the same. In contrast, the dimensions LA of high-strength portion 11A of one of the side walls 11, the dimension LA in the extending direction of the first ridge 123 of the high-strength portion 12A of the other side wall 12, the 2 / 3H ≦ LA ≦ 3H as long as it satisfies, it may be different.
[0072]
　Further, in the example shown in FIGS. 5A and 5B, the dimension LB is in the extending direction of the first ridge 123 of the low-strength portion 11B and the low-strength portion 12B which face each other, are the same. In contrast, the dimension LB in the extending direction of the first ridge 123 of the low-strength portion 11A and the low-strength portion 12A that face each other in the opposing direction of the pair of side walls 11 and 12, may be different. Also, in one of the side walls 11 may have dimensions LB of a pair of low-strength portion 11B that sandwich the high strength portion 11A are different. Also in the other side wall 12 may have dimensions LB of a pair of low-strength portion 12B that sandwich the high strength portion 12A are different. However, in any case, the dimensions of each LB is, it is desirable to meet the 3 / 5H ≦ LB. Thus the deformation degree due to impact as to result promote deformation of the low strength portion can be further suppressed.
[0073]
　In the structural member 10, edges are formed at the boundary between the top wall 13 and a pair of side walls 11, 12. Similarly, edges are made in the boundary between the flange 14 and the pair of side walls 11, 12. These edges extend in the longitudinal direction of the tubular portion. Ridge increases the impact strength of the structural member 10. The side walls 11, 12 connected to the top wall 13 is impacted surface via the ridges, high strength portion 11A, 12A and the low-strength portion 11B, 12B are arranged. Thus, it is possible to suppress the bending deformation of the structural member 10 due to the impact of the top wall 13.
[0074]
　Figure 6A is a diagram illustrating a modification of the arrangement of the low-strength portion 11B, 12B of the structural member 10 shown in Figure 2A. In the example shown in FIG. 6A, a portion in the height direction of the side wall 11 (z-direction), the low-strength portion 11B is provided. That is, in the side wall 11, a portion between the ends of the top wall 13 side to the end portion of the flange 14 side, the low-strength portion 11B is provided. Low strength portions 11B, in the height direction of the side wall 11 is provided between the one end 11a of the side wall 11 (top wall 13) from the position of the distance h, to the position of the distance hb from the other end 11b (flange 14) . That is, the end portion 11Ba which is closer to the one end 11a of the low-strength portion 11B (one end side), whereas there from the end 11a at a distance h, closer to the other end 11b of the low-strength portion 11B (the other end end 11Bb of) lies from the other end 11b at a distance hb. Low strength portions 11B has one end 11a (top wall 13) and the other end 11b (flange 14) is not in contact to both. Although not shown, the low-strength portion 12B of the side wall 12 that faces the low-strength portion 11B is also provided on a part of the height direction of the side wall 12. That is, each of the pair of side walls 11 and 12, the low strength portion 11B on a part of the height direction, is allowed to have a 12B. Even the modification shown in FIG. 6A, it is possible to suppress the protrusion degree by deformation of the structural member 10 of an impact.
[0075]
　In this case, in order to suppress the deformation degree, while the end 11a low-strength portion 11B, a distance h in the height direction of the side wall 11, 12 to the end 11Ba closer to one end 11a of the 12B of the side walls 11 and 12 it is desirable that the (1/4) H or less (h ≦ H / 4). On the one hand from the end 11a in the height direction of the side wall (1/4) in the region of the distance H, it is desirable to place the end 11Ba of the low-strength portion 11B. In order to suppress the deformation degree, preferably the distance h is (1/5) is preferably set to H below (h ≦ H / 5). Yield strength between the low-strength portion 11B, the end portion 11Ba and the one end 11a which is closer to the one end 11a of the 12B, the high strength portion 11A, may be the same as the yield strength of 12A.
[0076]
　In order to suppress the deformation degree, the distance in the height direction of the side wall 11, 12 from the other end 11b of the side walls 11 and 12 to the low-strength portion 11B, 12B hb is, (4/5) H or less (hb ≦ 4H / 5 ) that it is desirable to. To further suppress the deformation degree, the distance hb is preferably set to (1/2) H or less (hb ≦ H / 2).
[0077]
　However, very any value h and hb described above is allowed, in order to suppress the deformation degree, the size hc low intensity portion 11B, the height direction of the side wall 11, 12 of the 12B (z direction) is always (1 / 5) is required to be H or higher in order to suppress ((H / 5 ≦ hc). further deformation degree, the dimensions hc is (1/4) is preferably set to H above ((H / 4 ≦ hc).
[0078]
　Figure 6B in Figure 6A described above, it is a diagram showing a modified example in which h = 0.
[0079]
　Figure 6C in Figure 6A described above, it is a diagram illustrating a modification in which the hb = 0.
[0080]
　As illustrated in FIGS. 6A ~ FIG 6C, a low intensity so that the area from one end of the height direction of the ends of the side walls (1/4) up to H, the end of the one end of the low-strength portion is located section to form a. That is, the low strength portion is formed on at least a part of the region from the position on the side wall at a distance from one end of the side walls (1/4) of H up to one end of the side walls. Thus, when an impact is applied from one end side of the side wall, it is possible to reduce the degree of deformation of the structural member 10. Furthermore, to position the ends of the other end of the low-strength portion in a region from the other end (4/5) until H of the height direction of the ends of the side walls, it is allowed to form a low-strength portion . However, in order to suppress the deformation degree, the size in the height direction of the side wall of the low-strength portion is required to be at least 1 / 5H or more.
[0081]
　In the example shown in FIG. 6A ~ FIG 6C, among the ends of the side walls 11 and 12, and one end towards which is in contact with the top wall 13, a person who is in contact with the flange 14 as the other end, the distance h, hb, It was set hc. In this case, the distance as described above h, hb, by setting the value of hc, it is possible to reduce the degree of deformation of the structural member 10 when an impact is applied to the top wall 13. In contrast, among the height direction of the ends of the side walls 11 and 12, and one end towards which is in contact with the flange 14, a person who is in contact with the top wall 13 as the other end, the distance h, hb, the hc settings can also be. In this case, as in the above example, the distance h, hb, it is possible to set the value of hc. Thus, it is possible to further reduce the degree of deformation of the structural member 10 when an impact is applied to the closing plate 2.
[0082]
　6D is a diagram showing another modification of the high-strength portion 11A, 12A arranged in the structural member 10 shown in Figure 2A. In the example shown in FIG. 6D, the high strength portion 11A between the low-strength portion 11B is provided in the height direction of the side wall 11 from the other end (flange 14) to the position of the distance ha. In the height direction of the side wall, additional low-strength portion 11D is provided over a period of up to one end of the side wall 11 from the high-strength portion 11A (top wall 13). Yield strength of the additional low-strength portion 11D is 60 to 85% of the yield strength of the high strength portion 11A. Thus, the high strength portion 11A sandwiched between the low-strength portion 11B in the extending direction of the first ridge 123 may be provided in a part of the height direction of the side wall 11. In order to suppress the deformation degree, the distance ha is, for example, (3/5) H or more. In order to further suppress the deformation degree, it is desirable that the distance ha and (4/5) H or more. Although not shown, similarly high strength portion 12A of the side wall 12, in the height direction of the side wall 12 may be provided from the other end (flange 14) to the position of the distance ha. In this case, in the height direction of the side wall, additional low-strength portion is provided over between the high strength portion 12A to one end of the side wall 12 (top wall 13).
[0083]
　Thus, placing the end of the one end of the side wall (2/5) one end of the high-strength portion in the region of up to H, the other end of the side wall, the other end portion side of the end portion of the high-strength portion to place. In this case, additional low-strength portion between the end portion of one end side of the high-strength portion to one end of the side walls are provided. Thus, whereas when an impact is applied from the end, it is possible to further reduce the degree of deformation of the structural member 10.
[0084]
　In the example shown in FIG. 6D, one end of the side wall 11 is in contact with the top wall 13 and the other end is in contact with the flange 14. In this case, it is possible to reduce the degree of deformation of the structural member 10 when an impact is applied to the top wall 13. In contrast, among the height direction of the ends of the side walls 11 and 12, and one end towards which is in contact with the flange 14, a person who is in contact with the top wall 13 as the other end, as in the above example the distance ha value may be set for. In this case, it is possible to further reduce the degree of deformation of the structural member 10 when an impact is applied to the closing plate 2.
[0085]
　Figure 7A is a sectional view showing a modification of the cross-sectional shape of the structural member 10 described above. Structural member 10 shown in FIG. 7A, a pair of side walls 11, 12 having different shapes. A pair of side walls 11 and 12, the angle and against the flange 14, 14, different heights HR, HL each other. Therefore, they have different positions in the height direction of the pair of flanges 14 and 14. Also different from the first position 11mid half the height HR of the one side wall 11, the position in the height direction of the first position 12mid half the height HL of the other side wall 12. Thus, if the cross section of the structural member 10 is not symmetrical, in each pair of side walls 11 and 12, the height HR, HL, the height-direction center position 11mid, 12mid, are separately defined.
[0086]
　As shown in FIG. 7A, even when the cross section of the structural member 10 is not symmetrical, high-strength portion 11A of the pair of side walls 11, 12, 12A are arranged to face each other at least in part. Low strength portions 11B of the pair of side walls 11, 12, 12B are similarly disposed at a position opposite to each other at least in part. Further, as shown in FIGS. 6A ~ FIG 6D, the height direction of the part to the low strength portion 11B of the side walls 11, 12, 12B or high strength portion 11A, 12A may be provided. For example, as shown in FIG. 6A or FIG. 6C, the case of providing one low intensity portion 11B on the other end 11b side than the position of the edge 11a a distance h, 12B of the side wall 11, one side wall of the pair of side walls 11, 12 11 the distance h in the distance h is in the other side wall 12, it may be different to account HR, the HL in reference respectively.
[0087]
　In the example shown in FIG. 7A, the side wall 11 of one of the pair of side walls 11 and 12, it has a step. Thus, even if there is a step on the side wall 11, from one end in contact with the top wall 13 of the side wall 11, the height dimension to the other end in contact with the flange 14, the height HR of the side wall 11. That is, in the height direction, a dimension of up to the highest position from the lowest position of the side wall 11, and the height HR of the side wall 11. The side wall 11, the same applies to the case where there are irregularities or pores. In this case, the height direction is a direction perpendicular to the top wall 13. Distance h shown in FIGS. 6A ~ FIG 6D, ha, hb, hc is also set based on the distance in the height direction.
[0088]
　The other side wall of the pair of side walls 11, 12 12, whereas portion R (curved portion) connected to the end is formed. That is, the portion that is connected to one end of the side wall 12 has a rounded curved shape. Thus, the surface of the boundary portion between the side wall 12 and top wall 13 (square section) becomes a curved surface. In this example, among the portions R are formed, the farthest portion as an end portion of the side wall 12 from the height direction central position 12mid sidewall 12, the height HL and the distance h of the sidewall 12 is determined.
[0089]
　Although not shown, top wall 13, side walls 11 and 12, at least one surface of the flange 14 and the closing plate 2 may be curved rather than planar. In other words, top wall 13, side walls 11 and 12, at least one of the flanges 14 and closing plate 2 may be curved.
[0090]
　In the structural member 10, the dimension in the longitudinal direction of the tubular portion of the hat member 1 and the closing plate 2 are the same. The position of the longitudinal end portions of the hat member 1 and the closing plate 2 are aligned. In this case, the longitudinal length of the longitudinal length of the structural concrete member 10 of the tubular portion are equal. In contrast, in the longitudinal direction of the tubular section may have a different size and dimensions of the closing plate 2 hat member 1. Also, it may not be uniform position in the longitudinal direction of the end portion of the hat member 1 and the closing plate 2. That is, in the longitudinal direction of the tubular portion, the length and the length of the tubular portion of the structural member 10 may be different.
[0091]
　7B is a cross-sectional view showing a modification of the closing plate 2. In the example shown in FIG. 7B, closing plate 2 has a shape protruding in a direction away from the hat member 1. Specifically, closing plate 2 includes a joint 2a which is joined to the flange 14 of the hat member 1, an intermediate portion 2b between the junctions. Intermediate portion 2b has a shape protruding in a direction away from the hat member 1. In this example, the cross-sectional shape of the closing plate 2 is in the hat. The outer surface of the intermediate portion 2b, the outer surface and may be substantially parallel to the joint 2a.
[0092]
　In this manner, by the shape obtained by projecting a direction away closing plate 2 from the hat member 1, it is possible to adjust the height dimension of the structural member 10. The value of the height of the side walls as a reference of arrangement of the low-strength portion and a high-strength portion (H, HL, HR) does not vary with the height dimension of the closing plate 2.
[0093]
　Above with reference to FIGS. 7A and 7B, described asymmetric shape of the hat member 1, a step, the side wall end parts R, the shape of the closing plate 2, the plurality of features and the like. Other forms that combine all of the plurality of features (example shown in FIG. 7A or FIG. 7B), also structural member 10 employing at least one of the plurality of features are included in embodiments of the present invention.
[0094]
　Figure 8 is a diagram for explaining a height direction of the side wall 11, 12 when the top wall 13 is inclined. Figure 8 is a diagram showing the height direction of the structural member 10 where it is assumed impacted on the top surface 13. In the structural member 10 shown in FIG. 8, the top wall 13 of the hat member 1, the flange 14, 14 are not parallel. Further, the different lengths of the z direction of the one side wall 11 and the other side wall 12. If the top wall 13 is subjected to impact is assumed, the height direction of the side wall 11 and 12, and the direction perpendicular to the top wall 13. The height HL of each side wall 11, 11, HR is determined in the height direction of the side walls 11, 12 as a reference. In the case where the closing plate 2 it is assumed that shocked, a direction perpendicular to the closing plates, and the height direction of the side wall 11, 12.
[0095]
　Figure 9A ~ 9C are sectional views showing a modification of the structural member in the present embodiment. Figure 9A ~ 9C are showing a cross-sectional shape in a plane perpendicular to the longitudinal direction of the structural member. Examples shown in FIGS. 9A and 9B is an example of the configuration 4. Example shown in FIG. 9C is an example of the configuration 3. Figure 9D is a top view of the structural member shown in FIG. 9B in the z-direction.
[0096]
　In the modification shown in FIG. 9A ~ Figure 9C, instead of the hat member comprising two flanges, the channel member comprising a channel member or one of the flanges does not include a flange is used. Structural member 10 shown in FIGS. 2A ~ 2C are first ridge 123 and the second ridge 124 at both ends of the side wall 11, a and difficulty of deformation with respect to the vertical direction of the load to the top wall 13 (flexural rigidity) it is a contributing structure. In contrast, in the modification shown in FIG. 9A ~ Figure 9C, at least one of the two side walls, and has a contributing structure to the first ridge and the joint bending stiffness across the sidewall.
[0097]
　Structural member 10g shown in FIGS. 9A ~ Figure 9C, 10h, 10i are both provided with a channel member 31 of the channel, the closing plate 2 is joined to the channel member 31. Channel member 31 shown in FIGS. 9A ~ 9C are a top wall 13, two side walls 11, 12 extending from both ends of the top wall 13, joining the channel member 13 and the closing plate 2 two junctions 3r, equipped with a 3h. Two side walls 11, 12 facing each other. Two junctions 3r, 3h are provided on a part and closing plate 2 and are superimposed portions of the channel member 31. Joint 3r, 3h, for example, a spot weld or a laser weld. If the joint is arranged in a discontinuous (intermittent) in the extending direction of the first ridge 123 of the channel member 31, regarded as the joining portion in connecting a discontinuous joint position. That is, considered that there is a joint on a line connecting between a plurality of joints which are intermittently arranged. Between the junction and the first ridgeline is sidewall. Between the top wall 13 and two side walls 11 and 12, respectively, there is a first ridge 123, 123. For example, in the example shown in FIG. 9D, a plurality of joint portions 3h are arranged in the y direction (the extending direction of the first ridge 123). Virtual line 300 (the extending direction of the first ridge 123) y direction connecting the plurality of joint, the joint line.
[0098]
　In channel-shaped member 31 shown in FIGS. 9A and 9B, 2 two side walls 11 and 12 includes a first sidewall 11 and second sidewall 12. The other end opposite the one end portion of the top wall 13 side of the first side wall 11 is bent. Flange 14 extends from the bent portion. Flange 14 is overlapped with the closing plate 2. Flange 14 has a contact surface in contact with the closing plate 2. Flange 14 and the closing plate 2 are joined together at the junction 3r.
[0099]
　The first side wall 11 is located between the first ridge 123 and the flange 14 of one of the two first ridge 123, 123. Flange 14 and between the first side wall 11 is a second ridge 124. The second ridge 124 is an end portion of the flange 14. In this embodiment, the second ridge 124 extends in the longitudinal direction (y direction) of the first ridge line 123 in the same direction, that channel member 31.
[0100]
　The height HR of the first side wall 11, the height of the first sidewall 123 in a direction perpendicular to the top wall 13, i.e., the direction perpendicular to the top wall 13 of the first ridge 123 and the second ridge 124 it is the distance in.
[0101]
　The second sidewall 12 is located between the two first ridge 123 and junction 3h of the other of the first ridge 123, 123. The second side wall 12 is not bent. Some joint 3h side of the second side wall 12, is superimposed and the closing plate 2. Some joint 3h side of the second side wall 12 has a contact surface 1dh that contacts the closing plate 2. The second side wall 12 extends in the same direction as the contact surface 1Dh.
[0102]
　The height HL of the second side wall 12 is the distance between the first ridge 123 and junction 3h in the direction perpendicular to the top wall 13.
[0103]
　In channel-shaped member 31 shown in FIG. 9C, the two side walls 11 and 12, two first edges 123, 123, two junctions 3r, between 3h, respectively located. The height HR of the one side wall 11 of the two side walls is the distance in a direction perpendicular to the top wall 13 between the first ridge 123 and junction 3r. The height of the other side wall 12 of the two side walls HL is the distance in a direction perpendicular to the top wall 13 between the first ridge 123 and junction 3h.
[0104]
　In channel-shaped member 31 shown in FIGS. 9A ~ Figure 9C, a first side wall 11, the second side wall 12 facing the portion, the extending direction of the first ridge 123 (y-direction), the height HR including high strength portion 11A is formed over a distance of 2/3 or more than 3 times. Low strength portions 11B are arranged on both sides of the first ridge extending direction of the high-strength portion 11A (y direction). Second sidewall 12, the portion facing the first side wall 11, the extending direction of the first ridge 123 (y-direction), a high is formed over three times the distance 2/3 times the HL including strength portion 12A. Low strength portions 12B are arranged on both sides extending direction of the first ridge 123 of the high-strength portion 12A (e.g., see FIG. 9D). High-strength portion 11A, the yield strength of 12A is not less than 500 MPa. Low strength portions 11B, yield strength 12B, the high strength portion 11A, 60 to 85% of 12A. The high strength portion and a low strength portion of the channel member 31, FIG. 2, can be constructed in the same manner as any of the high-strength portion and a low strength portion of the structural member 10 shown in FIGS. 5-8.
[0105]
　In the example shown in FIG. 9A, a first side wall 11 second side wall 12 are parallel to each other. In contrast, in the example shown in FIG. 9B, a first side wall 11 second side wall 12 are not parallel to each other. In the example shown in FIG. 9B, a first side wall 11 second side wall 12, the distance from the top wall 13, and extends so that the distance therebetween becomes large. In this example, the first side wall 11 extends in a direction perpendicular to the top wall 13. The second side wall 12 extends in a direction having an angle with respect to the axis perpendicular to the top wall 13. Flange 14 extends outwardly from the other end portion of the closing plate 2 side of the first side wall 11. Structural members having a cross section as shown in FIG. 9A, for example, can be applied to the A-pillar.
[0106]
　In the example shown in FIGS. 9A and 9B, the closing plate 2 has a bent portion that is bent out of plane. Closing plate 2 in the extending direction of the ridge 2abh formed in the bent portion (y direction), the extending direction of the boundary line between the contact surface 1dh and closing plate 2 and does not contact surface in contact with the closing plate 2 in the side wall 12 is the same as that. The extending direction of the ridge 2abh formed in the bent portion of the closing plate 2 may be the same as the extending direction of the first ridge 123.
[0107]
　In the example shown in FIG. 9C, 2 two side walls 11 and 12 are both not bent. That is, the contact surface 1dr the sidewall 11 is in contact with the closing plate 2, extend in the same direction as the side wall 11. Contact surface 1dh the sidewall 12 is in contact with the closing plate 2, extend in the same direction as the side wall 12.
[0108]
　Closing plate 2 comprises two contact portions 2br contacting is superposed with channel member 31, and 2bh, two contact portions 2br, the intermediate portion 2a between 2bh. An intermediate portion 2a, 2 one contact portion 2br, during 2bh is bent. An intermediate portion 2a, 2 one contact portion 2br, ridge 2Abr, the extending direction of the 2abh the contact surface 1DR, 1Dh each side wall 11 in contact with the closing plate 2 at the side walls 11, 12 formed between the 2bh, is the same as the extending direction of the boundary line between the surface not in contact with the closing plate 2 in 12.
[0109]
　Figure 9A ~ 9C, the showing structural members 10 g, 10h, also in 10i, the same effect as the structural member 10 shown above in FIG. 2A ~ Figure 2C is obtained. The bonding section 3r, 3h is not limited to the weld. For example, fasteners such as screws, adhesive, or the adhesive portion of the brazing may be used as the joint. Further, in the above example, the direction of the height HR, HL criteria sidewalls 11 and 12 is a direction perpendicular to the top surface 13. In this case, the structural member, the deformation of the case impacted on the top surface portion 13 is further suppressed. Similarly to the structural member 10 shown in FIGS. 2A ~ Figure 2C, the structural member 10g shown in FIGS. 9A ~ Figure 9B, even in 10h, no particular restriction on the distribution of the intensity and strength of the flange 14. Furthermore, the structural member 10g shown in FIGS. 9A ~ Figure 9C, 10h, also the portion near the end of the junction 3h of channel member 31 in 10i also not particularly limited for the distribution of the intensity and strength. This part corresponds to the flange 14, since the distribution of the intensity and strength of this portion does not adversely structural member 10 g, 10h, particularly large impact on the performance of 10i.
[0110]
　In the example shown in FIGS. 2A ~ Figure 2C, the structural member 10 is formed to extend linearly in the longitudinal direction. In contrast, structural member 10 may be curved. For example, the structural member 10 may be a curved shape so as to be convex on the top surface 13 side or the closing plate 2 side. That is, the outer surface or the outer surface of the closing plate 2 of the top surface portion 13 may be curved structural members 10 so as to project.
[0111]
　Figure 10A ~ FIG 10D is a side view showing an example of a structural member 10 which is curved in the longitudinal direction. In the example shown in FIGS. 10A ~ FIG 10D, the structural member 10 is curved to be convex top wall 13 side. In FIG. 10A, the structural member 10 is curved at a constant curvature throughout the longitudinal direction. In FIGS. 10B and 10C, the curvature as a function of the longitudinal position of the tubular portion of the structural member 10 is changed. In Figure 10D, the structural member 10 is curved in a part of the length. In the example shown in FIGS. 10A and 10D, the structural member 10 is curved so as to be symmetrical as viewed from a direction perpendicular to the side walls 11, 12 (x-direction). 10B, the structural member 10 of FIG. 10C, and 10D includes a curved a portion (a curved portion) and a portion extending in a straight line (straight line portion). In the example shown in FIG. 10C, the bending portion is disposed on both longitudinal sides of the straight portion. That is, the straight line portion is arranged between the curved portion. In the example shown in FIG. 10D, the linear portions are arranged on both sides in the longitudinal direction of the bending portion.
[0112]
　By thus curving the structural member 10, it is possible to improve impact resistance against an impact in the direction opposite to the convex direction of the bending. For example, structural members formed by support both ends of the curved structural member 10, with respect to the direction of the impact faces the convex direction of the bending, with a high impact resistance.
[0113]
　In the example shown in FIGS. 10A and 10D, a pair of low-strength portion 11B between them in the high-strength portion 11A of the side wall 11 are both disposed on the curved portion of the structural member 10. In the example shown in FIGS. 10B and 10C, a pair of low-strength portion 11B between them in the high-strength portion 11A of the side wall 11 are both arranged in a linear portion of the structural member 10. When placing the low strength portion 11B and the high strength portion 11A on the straight portion, it is preferable to arrange the high-strength portion 11A in the middle of the straight portion. Thus, the high strength portion 11A is disposed in a portion moment increases when subjected to impact, high impact resistance is obtained.
[0114]
　Application Example of the vehicle]
　As described above, attached to the structural member 10 is used as a structural member for a vehicle, the structural member 10, to the vehicle in two while supporting a connecting portion of the longitudinally spaced tubular portion Sometimes. Structural member 10, for example, the vehicle body is used as a structural member of a bumper or vehicle door. Therefore, the vehicle body comprising a structural member 10, also a bumper or vehicle door, are included in embodiments of the present invention.
[0115]
　In the side wall 11 of the support structure member 10 by two connecting portions, between the two connecting portions, and two low-strength portion 11B spaced longitudinally, during which the high-strength portion 11A is disposed. Similarly on the other side wall 12 facing the side walls 11 and 12, the high strength portion 12A and the low-strength portion 12B is disposed. This makes it possible to in the structural member 10, hardly broken portions moment when a shock is applied increases. As a result, impact resistance is high structural member obtained.
[0116]
　In particular the central portion of the member moment tends to increase when the impact is applied. Therefore, the high strength portion 11A into two equal distance portion from the connecting portion of the (center between the two connecting portions), it is desirable to place the 12A. Further, it is preferable to adopt a configuration in which high-strength portion 11A in the extending direction center of the first ridge 123, 12A to support both ends of the structural member 10 disposed. Here, the structure for supporting the both end portions, in addition to the mode of supporting both ends of the structural members 10, and also includes embodiments for supporting the portion in the vicinity of both ends of the structural member 10.
[0117]
　When mounting the structural member 10 to the vehicle, it is often tubular the longitudinal direction of the structural member 10 is to place the structural member 10 so that along the contour of the vehicle. That is, as the impact in the case of a vehicle collision is perpendicular to the longitudinal direction of the structural member 10, often structural member 10 is attached to the vehicle. Further, on the outer top wall 13 of the vehicle, so that the closing plate 2 is positioned inside of the vehicle, there is the structural member 10 is attached to the vehicle. In this case, the high strength portion 11A is disposed in the center between the connecting portion of the structural member 10, the low-strength portion 11B are disposed on both sides thereof. Thus, in the event of an impact from the outside of the vehicle to the structural member 10, the degree of structural member 10 protrudes into the inside of the vehicle is reduced. Sometimes reverse the closing plate 2 is disposed on the outside of the vehicle. Again, the high strength portion 11A is disposed in the center between the connecting portion of the structural member 10, the low-strength portion 11B are disposed on both sides thereof. Sometimes closing plate 2 is disposed on the outside of the vehicle, in the event of an impact from the outside of the vehicle to the structural member 10, the degree of structural member 10 protrudes into the inside of the vehicle is reduced.
[0118]
　Structural members 10, as described above, may be curved. In this case, the structural member 10 is mounted to the vehicle so as to be convex toward the outside of the vehicle. Thus, in the event of an impact from the outside of the vehicle, it can be more difficult to break the structural member 10.
[0119]
　Structural member 10 may be a structural member constituting the vehicle body, a part of the bumper or the vehicle door. For example, A-pillar, B-pillar, side sill, roof rail, it is possible to use a structural member 10 floor members, the members constituting the vehicle body such as a front side member. Alternatively, attached to the body such as door impact beams or bumper, it is also possible to use a structural member 10 from an impact from the outside member to protect the equipment and passenger in the vehicle.
[0120]
　Figure 11 is a diagram showing an example of the structure member disposed on the vehicle of monocoque construction. In the example shown in FIG. 11, A-pillar 15, B-pillar 16, side sill 17, roof rail 18, with the bumper beam 19, the front side member 20, the door impact beam 21, the floor members 22, and the rear side members 23 as a structural member for a vehicle It is. At least one of these vehicle structural member may be constructed in a structure member 10 described above.
[0121]
　When applying the structural member 10 to the bumper beam 19, consisting of two end portions of the structural member 10 to the structure for supporting the front side member 20. In this configuration, if an impact is applied to the center of the bumper beam 19, the moment of the load is maximized. Longitudinal center to the high strength portion 11A of the bumper beam 19, 12A are disposed, the low strength portion 11B on both sides, 12B are arranged. Thus, deformation breakage due to impact of the center of the bumper beam 19 is suppressed.
[0122]
　When applying the structural member 10 to the door impact beam 21, it may be provided brackets to both end portions of the structural member 10. Structural member 10 may be attached to the door frame via a bracket at both ends. Again, when placed high-strength portion 11A, the 12A at the center in the longitudinal direction of the structural member 10, i.e., the center of both ends a coupling portion of the structural member 10 constituting the door impact beam 21, the high strength portion 11A when placing the 12A, it is possible moment upon impact is suppressed bending deformation in the most larger portion.
[0123]
　As the material of the structural member 10 constituting the structural member of the vehicle, tensile strength the use of ultra high strength steel (low-strength portion 11B, the portion of the tensile strength of the non-12B) is more than 780 MPa (or yield strength 400Mpa), of the effect is remarkable. Further, the low strength portion 11B of the structural member 10, the strength of areas other than 12B, by the tensile strength 980MPa or more (more than 500Mpa in yield strength), can be achieved more effectively. The material of the structural member 10 is not limited to steel. For example, aluminum and other metals may be used as the material of the structural member 10.
[0124]
　The vehicle that can be applied structural member 10 is not limited to the four-wheel vehicle such as an automobile shown in FIG. 11. For example, it is possible to use a structural member 10 to the structural member of the two-wheel vehicle. Furthermore, the structural member 10, not only the vehicle of monocoque structure can also be applied to the body of the frame structure. Further, the use of structural members composed of structural member 10 is not limited to a vehicle. For example, impact resistant container, building, ship, or, as a structural member of an aircraft or the like, can be used structural member 10.
[0125]
　Furthermore, embodiments employing the structural member 10 is not limited to the manner of connecting the two end portions of the structural member 10 to another member. Any two positions or more away 6H in the extending direction of the first ridge 123 of the structural member 10 may be connected to other member. That is, the two connecting portions are not restricted to both ends, may be arranged at any position of the structural member 10.
[0126]
　[Production Process]
　structural member 10 may be formed entirely of the same material. Structural member 10 is formed, for example, a steel plate. The manufacturing process of the structural member 10, a process of forming a hat member 1 having a low strength portion 11B, 12B and the high strength portion 11A, a 12A, a process of forming the closing plate 2, the hat member 1 and the closing plate 2 It includes a step of bonding. The manufacturing process of the hat member 1, provide strength difference to the material includes the step of forming a low-intensity region. The step of curving the hat member 1 and the closing plate 2 may be included in the manufacturing process. When bending the hat member 1 and the closing plate 2, for example, press bending, tensile bending, bending compression, bending rolls, push-through bending or eccentric plug bending or the like of the bending method is used.
[0127]
　The manufacturing process of the structural member 10, includes a step of forming a low-strength portion in the material. A method of forming a low strength portion is not particularly limited, for example, a steel sheet by roll forming and deforming the cross hat, a laser or high-frequency heating or the like method, locally heating the material, by performing quenching in, it is possible to produce a hat member 1 comprising a cured region. In this case, the area is not performed hardening becomes relatively low strength low strength portion. Further, after the strengthening entire hat member 1 performs thermal refining may be carried out partially annealed to form a low-strength portion.
[0128]
　Alternatively, it is also possible to produce a structural member 10 by using a hot press (hot stamping) technology. In the step of hot pressing, by varying the conditions of the heating or cooling partially in the same material, it is possible to form the low intensity regions in the material. For example, by using a steel sheet, the steel is heated above the temperature (Ac3 temperature) as the austenite single-phase region, performing quenching while performing molding using a mold. At this time, by attaching a difference in cooling rate, quench is roughly hard martensitic structure, mildly unit is a mixed-phase structure or bainite structure of soft ferrite and pearlite. Thus, the mildly portion may be a low intensity region. Further, after the entire member was high-strength portion of the martensitic structure by hot pressing, partially tempered may form a low-strength portion.
[0129]
　The manufacturing method of the structural member 10 is not limited to the above example. For example, tailored blanks, etc., other using known methods, may form a structural member 10 having a low strength portion.
[0130]
　In the structural member 10 of the above may high strength portion 11A, the yield strength of 12A distribution is not uniform. The constant region, variation in the yield strength is often a less 10% ±. Here, the high strength portion 11A, 90% of the maximum value Smax of the yield strength of 12A, is defined as a high-strength portion 11A, 12A of the yield strength SA (reference intensity) (SA = 0.9Smax). Yield strength greater 0.9SA less than 0.85SA (85% ~ 90% of SA) region (transition zone) is considered as part of the high-strength portion 11A, 12A. Yield strength in the high strength portion 11A, 12A is (85% SA) 0.85SA greater. That is, yield strength 0.85SA larger region is high strength portion 11A, 12A.
[0131]
　Figure 12 is a diagram showing an example of the distribution of yield strength of the portion including a low strength portion 11B, 12B and the high strength portion 11A, the boundaries 12A. 12, the vertical axis represents the yield strength, the abscissa indicates the position in the y-direction. In the example shown in FIG. 12, 90% of the maximum value Smax of the yield strength of the high-strength portion (0.9Smax) is defined as the yield strength SA of high-strength portion. In high-strength portion, area yield strength is more than 0.9SA is referred to as a constant region. Also, large 0.9SA smaller area yield strength than 0.85SA is a transition zone up to the constant region of the high-strength portion from the low strength portion. Transition zone is considered a high strength part, yield strength position of 0.85A is the boundary between the low-strength portion and the high strength portion. That is, the area yield strength greater than 0.85SA becomes a high strength part, the following areas yield strength 0.85SA is a low strength portion.
[0132]
　Yield strength of the low strength portion is a more 0.6SA 0.85SA less (60-85% of SA). Incidentally, also contain portions of the following partial 0.6SA surrounded by low intensity portions of the structural member 10, when a portion thereof is negligibly small influence on the deformation behavior of the structural members 10, low intensity part 11B, can be regarded as a part of the 12B.
Example
[0133]
　In this embodiment, the analysis of the deformation of the structural member when colliding the indenter to a structural member composed of a hat member and the closing plate in the simulation. Figure 13A is a diagram showing the configuration of an analysis model in the simulation. In this simulation, in a state of bridging the structural member 100 into two pedestal 33, the center portion in the longitudinal direction of the structural member 100, an indenter (impactor) 4, was analyzed deformation behavior when colliding.
[0134]
　13B is a diagram showing a structure viewed structural member 100 shown in FIG. 13A from the y direction. Structural member 100 includes a hat member 101, the closing plate 102. Hat member 101, top wall 113, flanges 114 extending in opposite directions outwardly from the end opposite to the top wall 113 of the pair of side walls 111, 112, and sidewalls 111, 112 opposite to each other extending from both ends of the top wall 113 including. Closing plate 102 is bonded to the flange 114. In the model shown in FIGS. 13A and 13B, the indenter 4 is conducted in the case of impinging on the top surface portion 113 moves in the z-direction, a simulation of the case where the indenter 4 collides with the closing plate 102 moves in the z-direction .
[0135]
　Mass of the indenter 4 is the 350 kg, the width WI of the Y-direction of the indenter 4 is 160 mm, the radius of curvature R of the impact surface 4s of the indenter 4 and 150 mm, the initial velocity of the indenter 4, was 4m / sec. Friction coefficient was 0.1. In the cross section of the structural member 100, the width W2 of the top wall and 50mm, was 50mm the respective heights H of the pair of side surfaces 111 and 112. Thickness t is 1.4mm structural member 100, the R of the structural member 100 5 mm, the length LY of the first ridge extension direction is the boundary of the side walls 111 and top wall 113 of the structural member 100 (y-direction) It was 1000mm. Distance LS between the pedestal 3 was 400 mm.
[0136]
　A pair of side walls 111 and 112, to place the high-strength portion 10A, was placed a low strength portion 10B in the y-direction both sides of the high-strength portion 10A. High-strength portion 10A is disposed in the central longitudinal structural member 10. Indenter 4 collides with the top wall 113. y-direction length LY of the structural member 100 is more than 6 times the height H of the side walls 111,112 (LY ≧ 6H).
[0137]
　13C is a diagram showing another configuration of an analysis model in the simulation. In the example shown in FIG. 13C, the both ends of the structural member 100 is bonded to two pedestal 33. Results of the simulation of the analysis model shown in FIG. 13C was similar to the results of the simulation of the analysis model shown in FIG. 13A. In addition to the simulation impinging indenter 4 to the top wall 113, simulated impinging indenter 4 to the closing plate 102 it was also conducted.
[0138]
　100 kgf / mm yield strength of the low strength portion 10B 2 , high-strength portion of the yield strength of the other region including the 10A 120 kgf / mm 2 as (about 0.83 the intensity ratio of the low-strength portion 10B with respect to the high strength portion 10A) , by varying the dimensions LB dimensions LA and the low strength portion 10B of the high-strength portion 10A, it was crash simulation.
[0139]
　Table 1 below (the yield strength of the low strength portion 10B, YP100kgf / mm the intensity ratio of 0.83 2 , the yield strength of the other parts including the high-strength portion 10A, YP120kgf / mm 2 ) and high strength It shows the deformation behavior obtained from the simulation results in the case where the size LA and the thickness t of the structural members 100 parts 10A is changed. In Table 1, Excellent deformation behavior column very good, Good is good, Poor shows poor. Evaluation of these deformation behavior was determined on the basis of the entry amount of the indenter. Poor means that you've broken in the early stages of deformation. Incidentally, Excellent, Good, meaning the evaluation Poor is the same in Table 5 shown below. Penetration of the indenter is referred to as the impactor stroke or indenter displacement. Table 1 is an analysis result in the case where collides the indenter 4 to the top wall 113. In contrast, even when colliding the indenter 4 in the closing plate 102, substantially similar analysis results as shown in Table 1 were obtained.
[0140]
[Table 1]

[0141]
　Figure 14 is a diagram of invasion indenter 4 shows a simulation result of the deformation of the structural member 10 when the 40 mm. In Figure 14, for Case1 ~ 3,5,7 ~ 9 shown in Table 1, respectively showing a state of deformation of the structural member 100. From the results shown in FIG. 14, Case2,3,5,7, that is, when the 2H / 3 ≦ LA ≦ 3H, range of a portion deformed by impact, is wider than that of the other Case1,8,9 there. That is, in the case of Case1,8,9, point bend is deformed mode of the "broken" bent as to protrude sharply occurs. For Case2,3,5,7 the deformation mode of the portion of the top surface and sidewalls of an impact collapse by the impact "section collapse" occurs.
[0142]
　Figure 15A is a graph showing in Case1 ~ 12 in Table 1, the simulation result of the impactor stroke when bent. 15A is a simulation result when the indenter 4 collide with the top surface portion 113. 15B is a simulation result when colliding the indenter 4 in the closing plate 102. Dimensions LA, the thickness t conditions Case1 to 12 in FIG. 15B is the same as Case1 dimension LA to 12, the thickness t conditions shown in Table 1.
[0143]
　In the results shown in FIGS. 15A and 15B, the Case2 ~ 7,10 ~ 12, Case1 than (i.e. the case without the low-strength portion 10B), impactor stroke when bending is large. Thus, in the case of Case2 ~ 7,10 ~ 12, compared to the case without the low-strength portion 10B, bending was found to be difficult to occur. In the case of Case3 ~ 7 i.e. H ≦ LA ≦ 3H, impactor stroke when bending is larger than the other. As a result, in the case of Case3 ~ 7, in particular, it was found that the break is less likely to occur. Furthermore, in the case of Case3,4 i.e. H ≦ LA ≦ 4H / 3, because the impactor stroke is further increased, it was found that more bending is Nikuku occur.
[0144]
　Further, towards the impactor stroke when added impact in closing plate 102 (FIG. 15B) is greater than the impactor stroke when an impact is added to the top wall 113 (FIG. 15A). For Figure 15B, because of the flange 114 on the inside (break initiator) bending of the structural member 100, as compared with the case of FIG. 15A, in order to suppress the decrease in rigidity due to bending deformation of the structural member 100, it is less likely broken .
[0145]
　Further, the strength of the low strength portion 10B, by changing the intensity ratio between the intensity of the other parts including the high-strength portion 10A, was crash simulation. Figure 16 is a graph showing the low strength portion 10B, when input impact load by changing the intensity ratio of the other parts including the high-strength portion 10A, the amount of deformation due to bending deformation. 16, the vertical axis represents the amount of intrusion structural member 10 in the impact direction (z-direction) (the amount of protrusion). The horizontal axis represents the ratio of the strength of the low strength portion 10B, to the intensity of the high-strength portion 10A (the intensity of the intensity / high-strength portion of the intensity ratio = low strength portion). In the graph of FIG. 16, a plot of diamonds, the yield strength of the high-strength portion YS120kgf / mm 2 shows the results of a, square plots, the yield strength of the high-strength portion 145Kgf / mm 2 in the case of the the results show a.
[0146]
　Intensity ratio, in the period of 0.60 to 0.85, the push-in amount with increasing intensity ratio is decreasing (arrow Y1). In this section, deformation mode of the structural member 10 has a collapsed section. In this section, the strength of the low strength portion 10B is low (the intensity ratio is 0.60 or less) case, although become deformed collapse section, entry amount is increased, the amount of intrusion when the intensity ratio exceeds 0.85 It becomes substantially the same. When the intensity ratio exceeds 0.85, intrusion volume increased sharply (arrow Y2). Moreover, increasing the intensity ratio intensity ratio 0.85 or more, penetration amount was increased according to the increase of the intensity ratios (arrow Y3). This is a boundary strength ratio 0.85, deformation mode, the collapse sectional, presumably because changes to break. Thus, deformation bent and strength of the low strength portion 10B is too high (the intensity ratio is high), push-in amount is increased. The results of Figure 16, from the viewpoint of reducing the amount of intrusion bending due to impact deformation, the intensity ratio is preferably 60 to 85%, the intensity ratio was confirmed that more preferably 70 to 85%.
[0147]
　Table 2 below, the low strength portion 10B, as shown in FIG. 6A, in the height direction of the side wall, illustrating the deformation behavior obtained from the simulation results of the case of providing a part of the side wall. This simulation is the same city as the height H of the size LA side wall of the high strength portions 10A in the extending direction of the first ridge line (LA = H), the extending direction of the dimension LB of the first ridge of the low-strength portion 10B (3/5) and H, the distance hb in the height direction of the side wall from the flange to the low strength portion 10B was H / 5. Stepwise changing the distance h from the top wall to the low-strength portion 10B in the height direction of the side wall, the distance h of each stage were to collide with the indenter 4 to the top wall 113. In the results shown in Table 2 below, the distance h from the top surface portion in the height direction of the side wall to the low-strength portion 10B is, when the 0 and, when the H / 5, the deformation behavior becomes very good, the distance h is deformation behavior at the time of the H / 4 became good.
[0148]
[Table 2]

[0149]
　Table 3, as shown in FIG. 6D, the high strength portion 10A, in the height direction of the side wall, provided from the flange to the position of the distance ha, obtained when a low-strength portion from high-strength portion 10A to the top wall It shows the deformation behavior obtained from the simulation results. This simulation is the same city as the height H of the size LA side wall of the high strength portions 10A in the extending direction of the first ridge line (LA = H), the extending direction of the dimension LB of the first ridge of the low-strength portion 10B (3/5) was used as H. The height direction of the distance ha of the side walls of the high-strength portion 10A is changed stepwise, the distance ha of each stage were to collide with the indenter 4 to the top wall 113. In the results shown in Table 3, the distance ha is, when the 4H / 5 or more, deformation behavior becomes very good, the distance ha became good deformation behavior when the 3H / 5.
[0150]
[table 3]

[0151]
　Table 4 below, the low strength portion 10B, as shown in FIG. 6B, in the height direction of the side wall, illustrating the deformation behavior obtained from the simulation results of the case of providing a part of the side wall. Low strength portion 10B is provided so as to contact with the top wall. This simulation is the same city as the height H of the size LA side wall of the high strength portions 10A in the extending direction of the first ridge line (LA = H), the extending direction of the dimension LB of the first ridge of the low-strength portion 10B (3/5) was used as H. Distance hb from the flange to the low-strength portion 10B is changed stepwise and the distance hb of each stage were to collide with the indenter 4 to the top wall 113. In the results shown in Table 4, the distance hb from the flange in the height direction of the side wall to the low-strength portion 10B is, H / 7, H / 5, and when the H / 2, deformation behavior becomes very good, distance hb became good deformation behavior when the 4H / 5.
[0152]
[Table 4]

[0153]
　Table 5 is the simulation using the model shown in FIG. 13C, it shows the analysis result of the deformation behavior of the structural members when changing the extending direction of the dimension LB of the first ridge of the low-strength portion 10B.
[0154]
[table 5]

[0155]
　The graph shown in FIG. 17 is a graph showing the amount of intrusion final impactor in Case13 ~ 16, respectively, in Table 5. The graph shown in FIG. 17, Case14 case of ~ 16, i.e., when the first ridge extending direction of the dimension LB of the low-strength portion of the (3/5) H, H, 2H, LB is (2/5 ) than in the case of H, the amount of intrusion impactor is reduced. Thus, by setting LB ≧ (3/5) H, was found to be smaller protruding degree. Further, in the range of (3/5) H ≦ LB ≦ 2H, than in the case of LB = (2/5) H, the amount of intrusion impactor is reduced, it was found that the protruding degree becomes small.
[0156]
　Having described an embodiment of the present invention, the above-described embodiment is merely an example for implementing the present invention. Accordingly, the present invention is not limited to the embodiments described above, it can be implemented by modifying the embodiment described above without departing from the scope and spirit thereof as appropriate.
DESCRIPTION OF SYMBOLS
[0157]
　1: Structure member
　2: closing plate
　11, 12: side wall
　13: top wall
　14: flange
　11A, 12A: High-strength portion
　11B, 12B: Low strength portions

The scope of the claims
[Requested item 1]
　At least one closing plate, a structural member and a hat member,
　said hat member,
　　and top wall,
　　and two first ridgeline on the both ends of the top wall,
　　the each said closing plate and two flanges joined,
　　the two second edges at the ends of the two flanges,
　　between said two first edges and said two second edges, two side walls positioned respectively has the door,
　the extending direction of the length of said first ridge line of the tubular section which is formed by said closing plate and the hat member, of the length of the two side walls in a direction perpendicular to the top wall not less than 6 times longer length H,
　each of said two side walls, the on opposed portions of the two side walls, the extending direction of the first ridge, 2/3 of the length H over 3 times or less of the distance more than doubled Formed Te, yield strength and high-strength portion that is not less than 500 MPa, arranged on both sides extending direction of said first ridge line of the high-strength portion, yield strength of 60 to 85% of the high intensity portion including a low strength portion,
structural member.
[Requested item 2]
　At least one closing plate, a structural member and a hat member,
　said hat member,
　　and top wall,
　　and two first ridgeline on the both ends of the top wall,
　　the each said closing plate and two flanges joined,
　　the two second edges at the ends of the two flanges,
　　between said two first edges and said two second edges, two side walls positioned respectively has the door,
　the extending direction of the length of said first ridge line of the tubular section which is formed by said closing plate and the hat member, of the length of the two side walls in a direction perpendicular to the closing plate not less than 6 times longer length H,
　each of said two side walls, the on opposed portions of the two side walls, the extending direction of the first ridge, 2/3 of the length H more than doubled 3 times or less Is formed over a distance of a high-strength portion which yield strength is at least 500 MPa, the high strength portion is of arranged on both sides extending direction of the first ridgeline 60 to 85% of the yield strength the high strength portion including a low strength portion is, a
structural member.
[Requested item 3]
　At least one closing plate, a structural member and a channel member,
　said channel member includes
　　a top wall,
　　and two first ridgeline on the both ends of the top wall,
　　wherein each closing and two joints to be joined to the plate,
　　between the two first edges and said two junctions, and two side walls positioned respectively,
　formed by the closing plate and the channel member the extending direction of the length of said first ridge line of the tubular portion is, in a direction perpendicular to said top wall, said it is six times more than the longer length H of the length of each side wall,
　said each of the two side walls, the on opposed portions of the two side walls, the extending direction of the first ridge, the formed over a length 3 times the distance 2/3 times more H, the yield strength a high-strength portion that is not less than 500 MPa, the They are arranged on both sides extending direction of the first ridge of the high-strength portion, yield strength; and a low strength portion 60 to 85% of the high intensity portion,
structural member.
[Requested item 4]
　At least one closing plate, a structural member and a channel member,
　said channel member includes
　　a one top wall,
　　and two first ridgeline on the both ends of the top wall,
　　the closing a flange that is joined to the plate,
　　and one second ridge on the edge portion of the flange,
　　a first side wall located between said first ridge and said second ridge line,
　　joined to the closing plate that the joining portion,
　　the second side wall located between the first edge line and the junction,
provided with,
　extending in the first ridge line of the tubular section which is formed by said closing plate and the channel member the length of the extending direction is in the top wall at least six times the first side wall length or the second longer length H of the length of the side wall in a direction perpendicular,
　said first sidewall, the second sidewall portion opposite to the The extending direction of the first ridge of the tubular portion, wherein is formed over a length 3 times the distance 2/3 times more H, a high-strength portion which yield strength is at least 500 MPa, the high-strength portion the first is arranged on both sides extending direction of the ridge, the yield strength comprises a low-strength portion 60 to 85% of the high intensity portion,
　Said second side wall, said first side wall portion opposite to, in the extending direction of the first ridge of the tubular portion, formed over 3 times the distance 2/3 times of the length H it is, yield strength and high-strength portion that is not less than 500 MPa, arranged on both sides extending direction of said first ridge line of the high-strength portion, low intensity yield strength of 60 to 85% of the high intensity portion and a part,
the structural member.
[Requested item 5]
　The length in the extending direction of the first ridge of the low-strength portion structure according to any one of claims 1 to 4, wherein the or less and 2 times 3/5 times the length H .
[Requested item 6]
　The high strength portion structural member according to any one of claims 1 to 5 arranged in the center in the extending direction of the first ridge in said tubular portion between the low-strength portion.
[Requested item 7]
　Between the opposite side of the other end with the first one end and the first edge line of the ridge line side of the side wall, toward the other end from the one end of said side walls, said from said one end of said side wall in the region between the to 1/4 position of the length to the other end, wherein there is an end portion of the one end side of the low-strength portion, structural member according to any one of claims 1, 3 and 4 .
[Requested item 8]
　Toward the one end from the other end of said side wall, in the area to the position of the length of (4/5) between said one end and said other end of said side wall, of the other end of the low-strength portion end is positioned,
　the length in the direction toward the other end from the one end of the low-strength portion is a length of 1/5 or more between said one end and said other end of said side wall, wherein structural member according to claim 7.
[Requested item 9]
　Adjacent to an end of the low-strength portion located between said one end and said other end of said side wall, including the area yield stress than the low strength portion is high, the structural member according to claim 7 or 8.
[Requested item 10]
　In between the first and one end of the ridge side to the first ridgeline opposite side of the other end of the sidewall, the one toward the end to the other end, the other end and the one end of the side wall in the region between the position of the length of (2/5) between the end of the one end side of the high-intensity part which is between the low-strength portion is located, to the other end of said side wall, the high strength portion second end side end portion is positioned in the high-strength portion of the over between the end of one end side to the one end of the side wall 60 to 85% of the yield strength the high strength portion additional low-strength portion is provided, the structural member according to any one of claims 1, 3 and 4 of.
[Requested item 11]
　Between the other end of the one end and the first edge line side opposite the first ridgeline side of the side wall, toward the other end from the one end of said side wall, said one end of said side wall wherein the region between the to 1/4 position of the length between the other end, wherein there is an end portion of the one end side of the low-strength portion, structural member according to claim 2.
[Requested item 12]
　Toward the one end from the other end of said side wall, in the area to the position of the length of (4/5) between said one end and said other end of said side wall, of the other end of the low-strength portion end is positioned,
　the length in the direction toward the other end from the low-strength portion and the one end is the length of 1/5 or more between said one end and said other end of said side wall, claim structure according to 11.
[Requested item 13]
　Wherein adjacent an end of the low-strength portion, the yield stress than the low strength portion comprises a region having a high A structure according to claim 11 or 12 located between said one end and said other end of said side wall.
[Requested item 14]
　Between the other end of the one end and the first edge line side opposite the first ridgeline of the sidewall, the one toward the end to the other end, the other end and the one end of the side wall in the region between the position of the length of (2/5) between the end of the one end side of the high-intensity part which is between the low-strength portion is located, to the other end of said side wall, the high strength portion second end side end portion is positioned in the high-strength portion of the over between the end of one end side to the one end of the side wall 60 to 85% of the yield strength the high strength portion additional low-strength portion is provided, structural member according to claim 2.
[Requested item 15]
　Structure according to any one of claims 1, 3, 4, 7 to 10 which is curved so as to be convex toward the top surface side.
[Requested item 16]
　Structural member according to any one of the closing plate according to claim 2, 11-curved to be convex side 14.
[Requested item 17]
　Wherein in a first extending direction in a plane perpendicular cross-section of the ridge, at least a portion of a virtual line segment which the closing plate connecting part which is joined to the hat member and the channel member, the said top wall It is between closing plate a structure according to any one of claims 1 to 16.
[Requested item 18]
　A structural member according to any one to claims 1 to 17 attached to the vehicle,
　said top wall or said closing plate, provided at two positions or more away 6H in the extending direction of the first ridge line a two connecting portion comprises two connecting portions connected to another member, the structural member for a vehicle is.
[Requested item 19]
　The high strength portion is centrally disposed between the two connecting portions, the structural member of claim 18.