Technical field
[0001]
　The present invention relates to a structural member and a vehicle using the same having impact resistance.
Background technique
[0002]
　Structural member used as a reinforcing member of the vehicle, high strength and light weight are required. For example, International Publication No. 2005/058624 (Patent Document 1), for the impact, the metal tube is mounted in a structure supported at both ends to the vehicle body 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
[0003]
Patent Document 1: WO 2005/058624
Summary of the Invention
Problems that the Invention is to Solve
[0004]
　When performing thinning for weight reduction of the structural member, usually also performs high strength together. The structural member, bending a shock exceeding the yield strength, bending portion protrudes. When thinning the structural member, the protruding degree tends to be large when broken by an impact. In contrast, for example, in the case of using the structural member of the vehicle, degree of projecting bent structural member which is deformed by the impact caused by the collision it is preferably smaller. This is because, the fact that the bent portion protrudes greater is that locally the energy absorption is occurring, because it means that the energy absorption capacity of the entire member is small. By the impact energy structural member to absorb more efficiently, it is possible to further suppress the impact energy applied to the occupant in the vehicle.
[0005]
　Accordingly, the present application discloses a vehicle using structural members and it can absorb the impact energy efficiently.
Means for Solving the Problems
[0006]
　Structural member in an embodiment of the present invention comprises a top wall, a hat member, a closing plate. The hat member extends from both ends of the top wall, wherein the other end portion opposite to a pair of side walls facing each other, in each of the pair of side walls, and one end portion of the top wall side of the side wall and a pair of flanges extending opposite outwardly of the pair of side walls. The closing plate is provided in contact with the pair of flanges of the hat member. Each of the pair of side walls, a region from one end of the side wall up to the position of a predetermined distance, having a low intensity region. Wherein the predetermined distance is 20 to 40% of the height of the sidewall. The yield strength of the low-strength region is 60-85% of the yield strength at the first position of the half height of said side wall.
Effect of the invention
[0007]
　According to the present disclosure, when impacted, it is possible to provide a structural member capable of absorbing effectively the impact energy.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008]
[Figure 1A] Figure 1A is a cross-sectional view of a structural member of an embodiment of the present invention.
FIG 1B] Figure 1B is a plan view of the structure member shown in FIG. 1A.
[Figure 1C] Figure 1C is a side view of the structural member shown in FIG. 1A.
FIG. 2 is a diagram schematically showing a state of collision test.
FIG. 3 is a diagram showing the deformation when the impact was applied to the structural member with a uniform intensity distribution.
[4] FIG. 4 is a diagram showing the deformation when a shock is added to a structural member having a low intensity region.
FIG. 5 is a diagram for explaining the deformation behavior of the structural members having a uniform intensity distribution.
FIG. 6 is a diagram for explaining the deformation behavior of the structural members having a low intensity region.
[Figure 7A] Figure 7A is a structural member is a view showing a state of deformed by an impact load.
[Figure 7B] Figure 7B is a structural member is a view showing a state of deformed by an impact load.
[8] FIG. 8 is a diagram for explaining the deformation behavior of the structural members having a low intensity region of a narrower range than FIG.
FIG 9A] FIG 9A is a cross-sectional view of a structural member according to a modification of this embodiment.
[FIG. 9B] FIG 9B is a sectional view showing a modification of the closing plate.
[10] FIG 10 is a diagram for explaining a height direction of the side wall 1b of the case where the top surface portion is inclined.
FIG 11A] FIG 11A is a sectional view showing a modification of the structural member.
FIG 11B] FIG 11B is a sectional view showing a modification of the structural member.
FIG 11C] FIG 11C is a sectional view showing a modification of the structural member.
[FIG. 11D] FIG 11D is a plan view of the structure member shown in FIG. 11B.
FIG 12A] FIG 12A is a cross-sectional view of a structural member of the present embodiment.
[Figure 12B] Figure 12B is a plan view of the structure member shown in FIG. 12A.
[FIG. 12C] FIG 12C is a side view of the structural member shown in FIG. 12A.
[13] FIG 13 is a diagram showing an example of the structure member disposed on the vehicle.
[14] FIG 14 is a diagram showing a B-pillar, which is constituted by a structural member in the present embodiment.
[15] FIG 15 is a diagram schematically showing the configuration of an analysis model in the simulation (order hat model).
[16] FIG. 16 is shown the dimensions of the structural member used in the simulation.
FIG. 17 is the case where shocked by changing the intensity ratio of the low intensity area and the other area is a graph showing the amount of deformation due to bending deformation.
[18] FIG 18 is a diagram schematically showing the configuration of an analysis model in the simulation (reverse hat model).
[19] FIG 19 is a graph showing the analysis results of a simulation of the forward hat model.
[20] FIG 20 is a graph showing the analysis results of a simulation of the inverse hat model.
[21] FIG 21 is a diagram showing an analysis result of the deformation behavior of the forward hat model.
[22] FIG 22 is a diagram showing an analysis result of the deformation behavior of the inverse hat model.
FIG. 23 is the intensity is a view showing a modification results in uniform specimen.
[24] FIG 24 is a diagram showing a modified result of the test specimen having a low intensity region in a part.
FIG. 25 is a measurement result of the impact experiments specimen is a graph showing the results of analysis by simulation using a model of the same structural member as a test sample.
DESCRIPTION OF THE INVENTION
[0009]
　Structural members of the first configuration in an embodiment of the present invention comprises a closing plate, and a hat member. The hat member includes a top wall, a pair of flanges provided in contact with the closing plate, extending from both ends of the top wall, a pair of side walls facing each other. The pair of side walls, a first end of the top wall side, wherein a second end portion of the one end portion opposite the other end where said pair of flanges extending to the opposite direction outside of the pair of side walls a. That is, the pair of flanges extending from the other end of said pair of side walls. Said pair of flanges is joined to the closing plate.
[0010]
　Each of the pair of side walls includes a high strength region comprising a center of the side wall in a direction perpendicular to the top wall, and a low intensity region 60 to 85% of the yield strength of the yield strength of the center of the side wall. The low intensity region in a direction perpendicular to said top wall, is formed from the one end portion of said side wall up to the position at the distance of 20-40% of the height of the side wall toward the other end . Further, the low intensity regions in the longitudinal direction of the side wall, is formed over a distance of more than the height of the side wall.
[0011]
　In other words, the low intensity regions in each of the pair of side walls is formed in a region from one end of the side wall up to the position of a predetermined distance (distance of 20-40% of the height of the sidewall) . That is, the low-strength region, from one end of the side wall, the said strong intensity region is formed over a boundary between the low intensity region. From one end of the side wall, the distance between the height direction of the border of the side wall of the boundary is 20 to 40% of the height of the side wall.
[0012]
　Also, the width in the longitudinal direction of each side wall of the low intensity regions in the pair of side walls each of which is the height direction of the width of each side wall (that is, the height of the side wall) or more.
[0013]
　In the first configuration, the height direction of each side wall is perpendicular to the top wall. The height of the sidewalls is the distance from one end of the side wall in a direction perpendicular to said top surface portion to the other end. Also in the second and fourth configurations described below, the height direction of the side wall is perpendicular to the top wall.
[0014]
　Longitudinal direction of each side wall is a longitudinal structural member, is also the longitudinal direction of the top wall. Structural member is an elongated member having a longitudinal direction (long axis). Longitudinal direction of each side wall, the same as the extending direction of the ridge (first ridge) formed between each side wall and the top wall. Longitudinal side walls will generally perpendicular to the height direction of the side wall.
[0015]
　Yield strength of the low intensity regions in the pair of side walls each of which is 60 to 85% of the yield strength of the center of the side wall in a direction perpendicular to said top surface. Here, the center of the side wall in the direction perpendicular to the top wall is one of the position of half the height of the sidewall.
[0016]
　The high intensity region in the height direction of the side wall, it said provided over the other end of the side wall from the boundary between the low intensity area and the high intensity area (end portion of the closing plate side).
[0017]
　The first configuration may be referred to the second configuration below. Structural member in the second arrangement 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. Each of said two side walls is provided with a low-intensity region. The low intensity regions in each of the two side walls in the second configuration, wherein the first ridge line toward the second ridge, wherein said first ridge line in a direction perpendicular to the top wall second It provided up to 20 to 40 percent of the distance between the ridge line. Further, the low-strength region, the extending direction of the first ridge is provided over the length of the region having a distance between said second ridge and said first ridge line in a direction perpendicular to the top wall . The low intensity region has a yield strength of from 60 to 85% of the yield strength of the center of the first ridge and the second ridge. Incidentally, the first ridge and the center of the second ridge is the same as the center of the side wall in a direction perpendicular to said top surface.
[0018]
　Each of said two side walls comprises said the low intensity region, a high strength region yield strength than the low intensity region. The high intensity region in a direction perpendicular to said top wall of each side wall, provided in a region from the second ridge line up to the boundary of the high intensity region and the low-intensity region. Center of the side wall of the side wall in a direction perpendicular to said top surface is contained in the high intensity regions.
[0019]
　Structural members of a third configuration of 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. Each of said two side walls is provided with a low-intensity region. Low intensity regions in each of the two side walls in the third configuration, wherein the second ridge line toward the first ridgeline, the closing plate to the second of the in a direction perpendicular ridge and the first It provided until 20-40% of the distance between the ridge line. Further, the low-strength region, the extending direction of the second ridge is provided over the length of the region having a distance between the first ridge and said second ridge in a direction perpendicular to the closing plate . The low intensity region has a yield strength of from 60 to 85% of the yield strength of the center of the side wall in a direction perpendicular to the closing plate.
[0020]
　Each of the pair of side walls in the third configuration, the high strength region comprising a center of the side wall in a direction perpendicular to the closing plate, low intensity from 60 to 85% of the yield strength of the yield strength of the center of the side wall and a region. The low intensity region, in a direction perpendicular to the closing plate, is formed from the other end of said side wall up to the position at the distance of 20-40% of the height of the side wall toward the one end portion . The other end portion is an end portion of the closing plate side of the both end portions in the height direction of the side wall. Wherein one end portion is an end portion of the top wall side of the both end portions in the height direction of the side wall. Further, the low intensity regions in the longitudinal direction of the side wall, is formed over a distance of more than the height of the side wall.
[0021]
　In the third configuration, the height direction of each side wall is a direction perpendicular to the closing plate. The height of the sidewalls is the distance from one end of the side wall in a direction perpendicular to the closing plate to the other end.
[0022]
　In a third configuration, each of said two side walls comprises said the low intensity region, a high strength region yield strength than the low intensity region. The high intensity region in a direction perpendicular to the closing plates of the respective side wall, provided in a region from the first ridge line up to the boundary of the high intensity region and the low-intensity region. Portion of the side wall of the center of the side wall in a direction perpendicular to the closing plate is included in the high intensity regions.
[0023]
　Structural members of a fourth configuration of 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. Each of said two side walls is provided with a low-intensity region. Low intensity regions in each of the two side walls in the fourth configuration, the first direction from the ridge line to the junction between the the top wall and the first edge line in the direction perpendicular the joint distance is provided up to 20 to 40%. Further, the low-strength region, the extending direction of the first ridge is provided over the length of the region having a distance between the joint portion and the first ridge line in a direction perpendicular to said top surface. The low intensity regions have 60 to 85% of the yield strength of the yield strength of the center of the side wall in a direction perpendicular to said top surface.
[0024]
　Each of said two side walls comprises said the low intensity region, a high strength region yield strength than the low intensity region. The high intensity region in a direction perpendicular to said top wall of each side wall, provided in a region from the junction to reach the boundary of the high intensity region and the low-intensity region. Portion of the central side wall of said first ridge line and the junction in a direction perpendicular to said top surface is included in the high intensity regions.
[0025]
　In a fourth configuration, the channel member has no ridge in contact with the closing plate. In each of the two side walls, the end opposite to the first edge line, rather than the second ridge, the joint is provided. Said sidewall, in a part of the joint portion is superimposed with the closing plate. In part superimposed sidewalls and closing plate, wherein the side wall has a contact surface that contacts the closing plate. The contact surface extends in the same direction as the side wall.
[0026]
　A height direction of the side wall is perpendicular to the top wall. The height of the sidewalls is the distance from the first ridge line in a direction perpendicular to said top wall to said junction.
[0027]
　Structural members of the fifth configuration of an embodiment of the present invention comprises at least one closing plate, and a channel member. The channel member includes a top wall, and two first ridgeline on the both ends of the top wall, a flange is joined to said closing plate, and a second ridge at the end of the flange, the a joining unit for joining the said the portion other than the flange closing plate of the channel member, a first side wall located between one and the second edge line of the two first edges, the of the two first ridge and a second side wall located between the other and the joining portion.
　It said first side wall includes a first low intensity regions. The first low intensity region, toward the second edge line from the first ridge line 20 to the distance between the first ridge and the second ridge line in a direction perpendicular to the top wall up to 40%, and the extending direction of the first ridge, provided over the length of the region having a distance between said second ridge and said first ridge line in a direction perpendicular to said top wall, said top having a yield strength of from 60 to 85% of the yield strength of the center of the side wall in a direction perpendicular to the surface.
[0028]
　It said second sidewall includes a second low-strength region. Said second low-strength region, the direction from the first ridgeline on the joint, up to 20-40% of the distance between the first ridge line and the junction in a direction perpendicular to said top wall, and the extending direction of said first ridge, said the top wall and the first edge line in the vertical direction than the distance between the joint portion provided on the length of the region, in a direction perpendicular to the top wall having a yield strength of from 60 to 85% of the yield strength of the center of the side wall.
[0029]
　In the configuration of the fifth, the first side wall, there is a second ridgeline on the end opposite the first ridgeline. In contrast, the second side wall, the end opposite to the first edge line, rather than the second ridge, the joint is provided. Said second side wall, in a part of the joint portion is superimposed with the closing plate. In the portion superposed the closing plate and the second side wall, said second side wall has a contact surface that contacts the closing plate. The contact surface extends in the same direction as the second side wall.
[0030]
　A height direction of the second side wall is perpendicular to the top wall. The height of the second side wall is the distance from the first ridge line in a direction perpendicular to said top wall to said junction.
[0031]
　Side walls by load applied to the top wall is compressed. In other words, the side walls are compressed between the support portion and the first edge line. If there is a second ridgeline on the member, a second ridge line in contact with the closing plate as a supporting portion. In this case, the side wall is a region between the first ridge and the second ridge. If the second ridge is not in member, the junction of the closing plate is a supporting portion. In this case, the side wall is a region between the junction and the first edge line. In the configuration of the first 1, 2, 4 and 5, the low strength of two side walls of the hat member or channel member is, having a high strength region including the center height direction of the side wall, a lower yield strength than the high intensity regions and a region. Low intensity region, from one end of the top wall side of each side wall, up to the position at the distance of 20-40% of the height of each side wall, and each side wall of the low-strength region longitudinally (i.e. first in the extending direction) of the ridge of formed over a distance of distance) than in a direction perpendicular to the top wall of the height (i.e., the first ridge line of each side wall to the second ridge or joint. We have found that by such a low intensity region is enhanced absorption efficiency of impact energy of the structural member when an impact is applied to the top wall. Specifically, if an impact is applied in a direction perpendicular to the top wall, in the low intensity region formed on the top wall side 20 to 40% of the area of ​​each side wall, perpendicular stress due to impact shock direction with dispersing in (longitudinal direction of the side wall), taking advantage of the rigidity of the high-strength region comprising a height direction center of each side wall has been found that it is possible to suppress the deformation of the structural member. Furthermore, the yield strength of the low intensity region of each side wall, by 60 to 85% of the yield strength at the center position in the height direction of each side wall, the impact energy absorption efficiency of the structural member, the required level It was found to be enhanced. That is, in the structural members of the structure of the first, second, and 4, when impacted, it is possible to absorb efficiently an impact energy.
[0032]
　In the third configuration above, two side walls of the hat member comprises a high strength region comprising a height direction center of the side wall, and a yield strength than the high intensity region is low low intensity regions. Low intensity region 20 to the second ridgeline of each side wall from (closing end of the plate side), the height of the side wall in a direction perpendicular to the closing plates (distance from the first ridge line to the second ridge line) up to the position of 40% of the distance, and the longitudinal direction (i.e. the extending direction of the second ridgeline) of each side wall, over a distance in a direction perpendicular to the closing plate from the second ridge line to the first ridge line It is formed over a region of length. We, the two side walls of the hat member, by forming such a low intensity regions, found that it is possible to enhance absorption efficiency of the impact energy of the structural member when an impact is applied to the closing plate . Specifically, if an impact is applied in a direction perpendicular to the closing plate, in the low intensity region formed on the closing plate side 20 to 40% of the area of ​​the side wall, with disperse stress due to impact in the longitudinal direction, taking advantage of the rigidity of the high-strength region comprising a height direction center of the side walls has been found that it is possible to suppress the deformation of the structural member. Furthermore, increasing the yield strength of the low intensity region of each side wall, by 60 to 85% of the yield strength at the center position in the height direction of each side wall, to a level required impact energy absorption efficiency of the structural member it has been found by the inventors to be. That is, in the structural member of the third configuration, when impacted, it is possible to absorb efficiently an impact energy.
[0033]
　In any of the first to fifth configurations, the low-strength region is preferably arranged in the longitudinal center of the side wall. The reason for this is as follows. The longitudinal center of the side wall is spaced from the longitudinal ends. These vicinity of both end portions are often supported is coupled to the other member. When a load in the center in a state where both end portions are supported is applied, the bending moment increases. The low intensity regions, by arranging the longitudinal center of the side wall, the low intensity regions are arranged in a position deformed by the impact is likely to increase. As a result, it is possible to increase the absorption efficiency of impact energy. Longitudinal direction of the side wall, in the configuration of the 1,2,4,5, and a first extending direction of the ridge line between the sidewall and the top wall, in the third configuration, between the side wall and closing plate the extending direction of the second ridgeline.
[0034]
　In any of the configurations of the first to sixth, wherein the top wall or the closing plate may include at least two connecting portions is connected to another member at a position apart from each other in the longitudinal direction of the side wall. In this case, the low intensity region be arranged centrally between the at least two coupling portions in the longitudinal direction of the side walls is desirable. The reason for this is as follows. Middle of the two connecting portions are separated from the position where it is supported by the other member. If a load is applied to the middle of the two connecting portions, the bending moment increases. Therefore, in the structure member supported by at least two coupling portions, by providing the low-intensity region in the center of the at least two coupling portions, the low intensity regions are arranged in a position deformed by the impact is likely to increase. As a result, it is possible to increase the absorption efficiency of impact energy.
[0035]
　The first, the second, or the fourth and fifth configurations, in each of the two side walls, the center of the tensile strength of the side wall in a direction perpendicular to said top face portion, be more 980MPa desirable. This is because, in the structure member such high strength, because the effect of the absorption efficiency of the impact energy can be preferably obtained. The height direction of the side wall, and the direction perpendicular to the top wall.
[0036]
　In the third configuration above, in each of the two side walls, the center of the tensile strength of the side wall in a direction perpendicular to the closing plate, it is desirable that the above 980 MPa. This is because, in the structure member such high strength, because the effect of the absorption efficiency of the impact energy can be preferably obtained.
[0037]
　It said first, second, also a vehicle provided with a fourth and fifth one of the structural members of the structure of, are included in embodiments of the present invention. In such a vehicle, said structural member, said the top wall is the outside of the vehicle, wherein the closing plate are preferably arranged so that the interior of the vehicle. Thus, from the outside of the vehicle, when an impact is applied against the top surface of the structural member, it can be absorbed efficiently bombarded by structural members.
[0038]
　Vehicle including a structural member of the third configuration is also included in the embodiments of the present invention. In such a vehicle, said structural member, said the closing plate outside of the vehicle, said top surface portion are preferably arranged so that the interior of the vehicle. Thus, from the outside of the vehicle, when an impact is applied against closing plate of the structural member, it can be absorbed efficiently bombarded by structural members.
[0039]
　In structural members of the first to fourth configurations, both end portions of the top wall are opposite end portions in the direction perpendicular to the longitudinal direction of the top wall. Incidentally, the longitudinal direction of the top wall is a longitudinal structural member, is also the longitudinal direction of the side wall. Longitudinal structural member is the direction of extension of the hollow portion surrounded by the hat member (or channel member) and closing plate. That is, the axial direction of the tubular portion formed in a hat member (or channel member) and the closing plate, the longitudinal direction of the structural member.
[0040]
　Two side walls extending from both ends of the top wall extend in the same direction with respect to the top wall. That is, the two side walls, so as to face each other, extend from both ends of the top wall. Two side walls has a structure for supporting the top wall from the inner surface of the top wall. The state in which two side walls facing the inner surface of the two side walls is not limited to parallel.
[0041]
　[Embodiment 1]
　Embodiment 1, the first, for the second, fourth, and fifth configurations. 1A is a cross-sectional view of a structural member of the embodiment of the present invention, FIG. 1B is a plan view of the structural member shown in FIG. 1A, FIG. 1C is a side view of the structural member shown in FIG. 1A. Configuration shown in FIGS. 1A ~ FIG. 1C, regarding the first and second configurations.
[0042]
　Structural member 10 shown in FIGS. 1A ~ FIG. 1C comprises a hat member 1 having a hat-shaped cross section, the closing plate 2 which is joined to the hat member 1. Structural member 10 has a closed cross section formed by the hat member 1 and the closing plate 2.
[0043]
　As shown in FIG. 1A, the hat member 1 has a top wall 1a, a pair of side walls 1b, and a pair of flanges 1c. A pair of side walls 1b extend from both ends of the top wall 1a, facing each other. A pair of flanges 1c, in each of the pair of side walls 1b, the one end portion of the top wall 1a of the side walls 1b extending from the other end opposite to the opposite direction outside of the pair of side walls 1b. Closing plate 2 is provided in contact with the pair of flanges 1c.
[0044]
　As shown in FIG. 1B, the boundary portion between the top wall 1a and a pair of side walls 1b (shoulder) 1ab the ridge extending in the longitudinal direction (hereinafter, referred to as the first ridge line 1ab.) To form a. First ridge line 1ab is a portion bent hat member 1 (bent portion). Both ends in the direction perpendicular to the longitudinal direction of the top wall 1a (x-direction) is the pair of first ridge line 1ab. A pair of side walls 1b from a pair of first ridge line 1ab extend respectively. A pair of side walls 1b extend in the same direction (z-direction). In the structural member 10, the dimension in the direction (y-direction) of extension of the edge (first edge line 1ab) formed at the boundary of the top surface 1a and a pair of side walls 1b, the direction in which the pair of side walls 1b are opposed to each other (x It is longer than the dimension in the direction). Longitudinal direction of the structural member 10 is the same as the extending direction of the first ridge line 1ab formed between the top wall 1a and side walls 1b.
[0045]
　As shown in FIGS. 1A and 1C, the boundary portion 1bc between each flange 1c and a pair of side walls 1b, the ridge extending in the longitudinal direction (hereinafter, referred to as a second ridgeline 1bc.) To form a. The second ridge 1bc is a portion bent hat member 1 (bent portion). In each of the pair of side walls 1b, the second ridge 1bc is formed at the other end opposite to the one end of the top wall 1a side of the both end portions of each side wall 1b. That is, the pair of second ridge 1bc at each other end of the pair of side walls 1b, extends in the direction in which the pair of flanges 1b are separated from each other.
[0046]
　As shown in FIGS. 1A and 1C, each of the pair of side walls 1b is a region from one end of the side wall 1b to the position of the distance Sh, it has a low intensity region 1s. Low intensity region 1s, the intensity than the surrounding is lower region. In a pair of side walls 1b, part other than the low strength region 1s becomes strength than the low intensity region 1s high strength region. In the height direction (the direction perpendicular to the top wall 1a) of each side wall 1b, the low intensity regions 1s, one end portion of the top wall 1a side (first ridge 1ab), the distance Sh from the first ridge line 1ab It is formed in the portion up to the position. That is, the boundary 1sk low intensity region 1s and the high intensity regions from the first ridge line 1ab at a distance Sh. And the boundary 1Sk, distance in the height direction of the side wall 1b of the first ridge line ab is the distance Sh. Portion from the boundary 1sk low intensity region 1s and the high intensity regions up to the second ridgeline 1bc (flange 1c) is a high strength region.
[0047]
　Further, as shown in FIG. 1C, the low-strength region 1s, in the longitudinal direction of the side wall 1b (first extending direction of the ridge line 1ab (y-direction)), over a distance of more than the height H of the side wall 1b forms It is. That is, the longitudinal length Sn sidewall 1b of the low intensity region 1s is greater than or equal to the height H of the side wall 1b. Here, the height of the side wall 1b from the first ridge line 1ab in the direction (z-direction) perpendicular to the top wall 1a (one end portion of the side wall 1b) to a second ridge 1bc (the other end portion of the side wall 1b) and of the distance. Thus, low-strength region 1s from the first ridge line 1ab to the position of the distance Sh in the height direction of the side wall 1b, and in the longitudinal direction of the side wall 1b, provided over the height H above the distance of the side wall 1b .
[0048]
　Thus, in the structural member 10, by providing the low-intensity region 1s in a part of the top wall 1a of the side walls 1b, when the impact is applied to the structural member 10, a smaller degree in the direction of bending deformation be able to. This inventors obtained as a result of careful observation of the state of deformation due to the impact of the structural members is based on the following findings. Inventors have conducted crash test (simulation) impinging indenter to a structural member composed of a hat member and the closing plate, to observe the deformation behavior of the structural member. Figure 2 is a diagram schematically showing a state of collision test. The crash tests, placing spanned the structural member 10a into two pedestal 12. In the middle position of the two platform 12, impinging indenter 11 against the structural member 10a.
[0049]
　Figure 3 is a diagram showing the deformation when a shock is added to the structural member 10b having a uniform intensity distribution. Figure 4 is a diagram showing a modification of the time plus the same shock and FIG. 3 in a structural member 10c having a low intensity region similar to FIGS. 1A ~ FIG 1C. As shown in FIG. 3, if the intensity distribution is uniform structural member 10b, bent like portion bent is protruded sharply. It is referred to as a break this deformation mode. In contrast, in the case of a structural member 10c having a low strength portion in the side wall, as shown in FIG. 4, a portion of side walls extending top wall which shocked from both ends from collapsing by the impact. The deformation mode is referred to as a collapse section. As compared with the case of FIG. 3, is better in the case of FIG. 4, the area of ​​the member that contribute to the deformation to shock absorption when subjected to the same impact load is large, as a result, degree of projection to the bending direction of the structural member It is small.
[0050]
　Figure 5 is a diagram for explaining the deformation behavior of the structural member 10b having a uniform intensity distribution. Figure 6 is a diagram for explaining the deformation behavior of the structural member 10c having a low intensity region as shown in FIGS. 1A ~ FIG 1C. 5 and 6 show a side of the structural member, i.e. the configuration seen from the side wall.
[0051]
　As shown in FIG. 5, the structural member 10b having a uniform intensity distribution, the impact, the deformation generated in the bending deformation origin P, as top wall and the side wall is wedged in a side view, the side wall height It is traveling in the direction. As a result, it bent bending so as to protrude sharply in the direction (the side wall in the height direction). In some cases, the fall is cracked sidewall.
[0052]
　As shown in FIG. 6, the structural member 10c on the top surface of the side wall having a low intensity region 1SC (area indicated by dots in FIG. 6), the deformation proceeds from a bending deformation origin P inward, low intensity regions 1SC Upon reaching the boundary, without directed to intensity is high region than the low intensity regions 1SC, tends to proceed in relatively low strength transverse direction (longitudinal direction of the structural member 10c). Therefore, deformation spreads in the longitudinal direction, deformation degree of the bending direction (the side wall in the height direction) is reduced.
[0053]
　Furthermore, the structural member consists of a hat member and the closing plate, if bending deformation in the direction perpendicular to the top wall, easily broken near the center of the height of the side walls. That tends to be a starting point of deformation broken near the first position of half the height of the side walls. 7A and 7B are diagrams illustrating a hat member having a sidewall 1db extending top wall 1da from both ends, the structural member 10d consists of a closing plate 2d is, a state in which deforms under impact load. When an impact load is applied to the top wall 1da is input, the deformation angle of the shoulder portion of the hat member (bent portion of the boundary of the top surface portion 1da and side walls 1 db), bending the central region in the height direction of the side wall 1 db, resulting , the structural member 10d is crushed. The sidewall 1db bent to avoid to easily generate, the intensity of the central region in the height direction of the structural member 10 in the side wall 1b shown in FIGS. 1A ~ FIG 1C are high strength.
[0054]
　That is, in the structural member 10, the intensity of the position 1mid the central height of the side wall 1b (1 of 2 minutes) to some extent strongly, the top wall 1a side middle in the height direction position 1mid wall 1b, the central position 1mid providing lower strength than the low intensity region 1s. Range of the low intensity regions 1s and, by appropriately setting the intensity ratio of the low intensity region 1s to the height direction central position 1Mid, as the side wall 1b at the center position 1Mid broken not easily occur, further , it is possible to increase the degree of longitudinal collapse of the side wall 1b at the top surface 1a side from the central position 1Mid. As a result, it is possible to deformation behavior as shown in FIG. 6, the deformation degree of the bending direction is reduced.
[0055]
　Incidentally, deformation behavior shown in FIGS. 7A and 7B is not limited to the case where collides the indenter top wall of 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 a force in the direction perpendicular statically longitudinally pressing the indenter into top wall bending deformation can be the same deformation behavior.
[0056]
　Further, as shown in FIG. 6, in order to reduce the degree of deformation of the bending direction, by the inventors width is also important in the longitudinal direction of the low intensity region 1s (first ridge 2 in the extending direction) It has been found. Figure 8 is a longitudinal length Sn low intensity regions 1SC, is a diagram for explaining the deformation behavior in the case of less than 1 (H / 2) half the height H of the side wall 1b. As shown in FIG. 8, when the longitudinal direction of the width of the low intensity region is narrow, deformation progresses from the bending deformation origin P to the inside, becomes quickly reach the boundary of the low intensity region 1sc high strength region in the longitudinal direction . As a result, longitudinal collapse is limited, becomes deformed in the height direction easily proceeds.
[0057]
　We, as a result of the bending test and analysis of the structural member under various conditions, when the bending deformation is the structural member, the range of longitudinal deformation was found to be a height approximately the same sidewall. Further, the inventors of the longitudinal width of the low intensity region 1SC, by more than the height of the side walls has been found that the deformation due to impact longitudinally dispersed, it is possible to reduce the degree of deformation of the bending direction .
[0058]
　We, on the basis of the above findings, and conceived to constitute the structural member 10 as follows. Each of the pair of side walls 1b shown in FIGS. 1A and 1C, a region up to the position of the distance Sh from one end of the side wall 1b, having a low intensity region 1s. Distance Sh low intensity region 1s of the side wall 1b may be 20 to 40% of the height H of the side wall 1b. Yield strength of the low-strength region 1s may be 60 to 85% of the yield strength at the first position of half the height H of the side wall 1b 1mid (i.e., the height direction central position 1mid).
[0059]
　That is, in the cross section of the hat member, between the top surface 1a side end of the side wall 1b to a height 20 to 40% of the length of the H of the side wall 1b, 50% of the positions of the height H of the side wall 1b (i.e. the side walls low intensity regions 1s yield strength than portions is 60 to 85% of the 1b height direction central) are continuous. In other words, the low intensity regions 1s from the first ridge line 1ab toward the second ridge 1bc, 20 ~ of the distance between the first ridge line 1ab and second ridge 1bc in a direction perpendicular to the top wall 1a It provided up to 40% position. Yield strength of the low-strength region 1s is 60 to 85% of the yield strength of the side wall 1b at the center of the first ridge line 1ab and second ridge 1bc.
[0060]
　Thus, for example, deformation behavior when a shock is applied to the top wall 1a becomes likely to collapse cross section shown in FIG. As a result, it is possible to reduce the degree of bending deformation in the direction perpendicular to the top wall 1a. Thus, the structural member 10, when impacted, it is possible to absorb a larger impact energy in a small deformation. In other words, the structural member 10 can absorb the impact energy efficiently.
[0061]
　The distance Sh low intensity region 1s is more preferable to be more than 35% of the height H of the side wall 1b, the I 30% still preferred. The distance Sh is more preferably a more than 25% of the height H of the side wall 1b. And intensity of the low-strength region 1s of the side wall 1b, the ratio of the intensity of the height direction central position 1Mid (intensity ratio) is more preferably a 80% or less. Also, the intensity ratio is more preferably a 70% or more.
[0062]
　The low intensity regions 1s, in the longitudinal direction of the side wall 1b, preferably formed over a height H above the distance of the side wall 1b. In other words, the low intensity regions 1s is the extending direction of the first ridge line 1ab, provided over the length of the region having a distance between the first ridge line 1ab and second ridge 1bc in a direction perpendicular to the top wall 1a. Thus, easily allowed to proceed deformation in the longitudinal direction can be suppressed more displacement in the bending direction. The extending direction of the dimension of the first ridge line 1ab low intensity region 1s is preferably to 1.5 times the height of the side wall 1b (3H / 2) or more, 2 times the height of the side wall 1b (2H ) it is more preferably not less than.
[0063]
　Tensile strength in the height direction central position 1mid sidewall 1b, for example, it is desirable that the above 980 MPa (or yield strength 500 MPa). Thus, to ensure the strength of the height direction central position 1Mid wall 1b, it can be hardly broken side wall 1b in this position 1Mid. The region other than the low strength region 1s of the structural member 10 can be the same intensity and position 1mid in height direction center.
[0064]
　Between the first ridge line 1ab and second ridge 1bc, region from the end of the low intensity region 1s to a second ridgeline 1bc (flange 1c) is a high strength region. Yield strength of the high strength region is higher than the yield strength of the low intensity regions 1s. The intensity distribution in the high-intensity region, is not necessarily uniform.
[0065]
　The low intensity regions may be provided on at least a portion of the top wall 1a, a low intensity region may not be provided on the top wall 1a. The bending deformation of the structural member 10, the influence of the intensity of the side wall 1b is dominant has been found by the inventors. Strength of top wall 1a, as compared to the intensity of the side wall 1b, a small effect on the bending deformation.
[0066]
　As shown in FIG. 1A, the hat member 1 is provided with a pair of flanges 1c, a pair of side walls 1b extending vertically bent from the pair of flanges 1c, and a top wall 1a to be sandwiched between a pair of side walls 1b. In the example shown in FIG. 1A, side walls 1b is perpendicular to the flange 1c. The pair of side walls 1b are the same length. Flange 1c and the top wall 1a are parallel. The distance Sh low intensity region 1s of the one side wall 1b of the pair of side walls 1b, the distance Sh low intensity region 1s of the opposing other side wall 1b are the same. 1A, the intensity distribution of the structural member 10 has a symmetrical.
[0067]
　Configuration of the structural member 10 is not limited to the example shown in Figure 1A. For example, the angle between the side wall 1b and the flange 1c need not be 90 degrees (a right angle). Similarly, not limited to the angle between the side wall 1b and the top wall 1a 90 degrees (a right angle). For example, a cross section perpendicular to the longitudinal direction of the structural member 10 may be a trapezoidal shape. That is, closed section of the composed top wall 1a, side walls 1b and closing plate 2 may be a trapezoid. In this case, the cross-sectional shape in a plane perpendicular to the first edge line 1ab may be a symmetrical, it may not be symmetrical. The pair of side walls 1b, it may be different from each other in length. As a result, the flange 1c and the top wall 1a may not be parallel. The height of the pair of flanges 1c (located in the z-direction) may be different from each other.
[0068]
　Further, the sectional shape of the corner (shoulder) bounding the sidewall 1b and top wall 1a, may be formed R (roundness i.e. curved portion). Similarly, the cross-sectional shape of the corners of the bounding side walls 1b and the flange 1c (shoulder), may be formed R (roundness i.e. curved portion). The surface of the side wall 1b and / or top wall 1a can be curved rather than planar. That is, the side wall 1b and / or top wall 1a may be curved. Incidentally, the curvature radius of R is too large at the corners of the side wall 1b and the top surface 1a, function sidewall 1b is support a load in the height direction is reduced. Therefore, the radius of curvature of the inner surface of the R (curvature) of the corner of the side wall 1b and the top surface 1a is, for example, 15mm or less. Alternatively, the radius of curvature of the inner surface of the corner of the side wall 1b and the top surface 1a R (curvature), for example, less than one third of the height H of the side wall 1b, and (R ≦ H / 3).
[0069]
　At least one of the pair of side walls 1b, recesses (grooves), convex portions (ridges), step or holes may be provided. The top wall 1a, the recess (groove), the convex portions (ridges), step or holes may be provided. However, concave portions formed on the sidewalls 1b or top wall 1a (groove), the convex portions (ridges), the step or hole needs to be a size that does not significantly affect the deformation behavior of the structural member 10 . For example, the structural member 10 may be a two-stage hat shape or three or more stages of the hat-shaped to form a convex portion on the top surface 1a.
[0070]
　When forming the R (roundness i.e. curved portion) in the corners of the bounding wall 1b and the top surface 1a of the boundary of the corner or the side wall 1b and the flange 1c, in a cross section perpendicular to the longitudinal direction, of the portion R is formed, farther R blind from the height direction central position 1mid sidewall 1b (the end of the curved portion) as an end of the side wall 1b, to determine the distance Sh height H and low intensity regions 1s of the side wall 1b.
[0071]
　That is, the top surface 1a of the end of the curved portion between the side wall 1b and the top surface 1a (curved portion) of (R blind) as one end of the side wall 1b, the side wall 1b of the height H and the low intensity regions 1s determining the height direction of distances Sh. Further, the flange 1c side of the end of the curved portion between the side wall 1b and the flange 1c (curved portion) (R blind) as the other end portion of the side wall 1b, the height of the height H and the low intensity regions 1s of the side wall 1b to determine the direction of the distance Sh.
[0072]
　Similarly, based on the first ridge line 1ab and second ridge 1bc, determines the height direction of distances Sh height H and low intensity regions 1s of the side wall 1b. In this case, specifically, the first ridge line 1ab is, R top wall 1a side end of the (curved portion) (R blind) between the side wall 1b and the top wall 1a, ie, R a (curved portion) farther R blind from the height direction central position 1mid sidewall 1b and (an end of the curved portion). The second ridge 1bc, the flange 1c side edge (R stoppage) of R (curved portion) between the side wall 1b and the flange 1c, i.e., the position in the height direction center of the side wall 1b of the R (curved portion) 1Mid and the farther the R blind (end of the curved portion).
[0073]
　Here, the height of the side wall 1b is the dimension in the height direction from one end portion of the side wall 1b to the other end. In other words, the height of the side wall 1b is the dimension in the direction perpendicular to the top wall 1a from the first ridge line 1ab wall 1b to the second ridgeline 1bc. Distance Sh low intensity region 1s is a dimension in a height direction from one end portion of the side wall 1b to the boundary of the low intensity region 1s of the side wall 1b. That is, the distance Sh low intensity region 1s is dimensioned in the direction perpendicular to the top wall 1a from the first ridge line 1ab to the boundary between the low-intensity region 1s and high intensity regions of the side wall 1b. 1 position 1mid half the height sidewall 1b is the position of the center in the height direction of the side wall 1b. That is, the first position 1mid half the height sidewall 1b is the position of the first ridge line 1ab and the side wall 1b of the center of the second ridge 1bc in a direction perpendicular to the top wall 1a.
[0074]
　Height direction of the side wall 1b is a direction perpendicular to the top wall 1a. The direction perpendicular to the top wall 1a, specifically, a direction perpendicular to the plane of the surface of the top wall 1a. Top wall 1a is, in a cross section perpendicular to the longitudinal direction, the recess, protrusion, when including the step or curved portion, and a direction perpendicular to the virtual plane connecting the two first ridge line 1ab, the direction perpendicular to the top wall to.
[0075]
　Closing plate 2 is bonded to both sides of the flange 1c of the hat member 1 is fixed. Closing plate 2, hat member 1 when an impact load is applied to the top wall 1a of the hat member 1 is suppressed from being crushed by open mouth. The closing plate 2, irregularities may be stepped or hole is provided. Method of joining Closing play and 2 and the hat member 1, as long as it fixes the both is not particularly limited. For example, by welding or fastening members may be joined together. Also, closing plate 2 is not limited to a flat plate, for example, it may be formed in cross-section a hat-type.
[0076]
　In the example shown in FIG. 1B, the structural member 10 is formed to extend linearly in the longitudinal direction. In contrast, structural member 10 may be curved in the longitudinal direction. For example, it is possible to look from side (x direction), and a curved shape so as to be convex on the top surface 1a side (z + direction). Further, it may be curved structural member 10 when viewed from above (z-direction). The width of the top wall 1a (the length of the direction perpendicular to the longitudinal direction (x-direction)) are not necessarily uniform. The height of the side wall 1b (length in the z direction) is not necessarily uniform.
[0077]
　9A is a cross-sectional view of a structural member 10e according to a modification of this embodiment. Structural member 10e has different pair of side walls 1br, the 1bh shapes. A pair of side walls 1br, 1bh is angle and flanges 1cr, for 1ch, different heights HR, HL each other. Therefore, a pair of flanges 1cr, the position in the height direction of the 1ch are different. Also different from the first position 1midr half the height HR of the one side wall 1br, the position in the height direction of the first position 1midh half the height HL of the other side wall 1bh. The distance ShR low intensity regions 1sr of one side wall 1br, distance ShL low intensity regions 1sh the other side wall 1bh are different. Thus, if the cross section of the structural member 10e is not symmetrical, a pair of side walls 1br, in each 1bh, height HR, HL, the height-direction center position 1midr, 1midh, low intensity regions 1sr, 1SH is separately It is set.
[0078]
　In the example shown in FIG. 9A, a pair of side walls 1br, one side wall 1br of 1bh has a step. Thus, the side walls 1br, even if there is a step, a height dimension from the one end portion of the side wall 1br to the other end, the height HR of the side wall 1br. That is, in the height direction, a length of up to the highest position from the lowest position of the side wall 1br, the height HR of the side wall 1br. The sidewall 1br, it is same when there are irregularities or pores. Further, the distance ShR low intensity region, similarly, in the height direction, a dimension of up to the highest position from the lowest position of the low intensity regions 1sr, the low intensity regions 1sr distance ShR.
[0079]
　The other side wall 1bh of the pair of side walls 1b, meanwhile the end R (curved portion) is formed. In this example, among the portions R (curved portion) is formed, a portion (end of the curved portion) farther R blind from the height direction central position 1mid sidewall 1bh as an end of the side wall 1bh, sidewall 1bh the height HL and low intensity regions distance 1SH SHL is determined for.
[0080]
　Figure 9B is a sectional view showing a modification of the closing plate 2. In the example shown in FIG. 9B, the closing plate 2 has a shape protruding in a direction away from the hat member 1. Specifically, closing plate 2 comprises a flange 1cr hat member 1, and the joint portion 2a is joined to the 1ch, the 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. In Figure 9B, the outer surface of the intermediate portion 2b is has an outer surface of the joint portion 2a and substantially parallel, may not be parallel.
[0081]
　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. The value of the height of the side walls as a reference of arrangement of the low intensity regions (H, HL, HR) does not vary with the height dimension of the closing plate 2. Furthermore, the structural member 10e1 shown in Figure 9B, the shape of the cross section of a plane perpendicular to the longitudinal direction is not symmetrical with respect to the height direction axis, which may be symmetrical as shown in Figure 1A.
[0082]
　Figure 10 is a diagram for explaining a height direction of the side wall 1b of the case of top wall 1a is inclined. In structural members 10e3 shown in FIG. 10, a top wall 1a of the hat member 1, the flange 1cr, 1ch is not parallel. Moreover, the different z-direction of the length of one side wall 1br and the other side wall 1bh. Sidewall 1br, the height direction of the 1bh is a direction perpendicular to the top wall 1a. Each side wall 1br, height 1bh HL, HR and, each low intensity regions 1sr, one end of the 1SH (first ridge 1bcr, 1bch) from the boundary 1Skr, distance to 2skh ShR, ShL is sidewall 1br, 1bh It is determined in the height direction as a reference. Therefore, the side wall 1br, one end portion of the surface of the 1bh (first ridge 1abr, 1anh) are different and the distance from to the other end (second ridge 1bcr, 1bch), the height HR, HL.
[0083]
　Figure 11A ~ FIG. 11C is a sectional view showing a modification of the structural member in the present embodiment. Figure 11A ~ FIG. 11C shows a cross-sectional shape in a plane perpendicular to the longitudinal direction of the structural member. Figure 11D is a plan view of the structural member 10h shown in FIG. 11B in the z-direction. Examples shown in FIGS. 11A and 11B, regarding the configuration of the fifth. Example shown in FIG. 11C, relating to the fourth configuration.
[0084]
　In the modification shown in FIGS. 11A ~ FIG 11C, 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. 1A ~ FIG. 1C, the first ridge line 1ab and second ridge 1bc across the side wall 1b is, in and difficulty of deformation with respect to the vertical direction of the load to the top wall 1a (flexural rigidity) it is a contributing structure. In contrast, in the modification shown in FIG. 11A ~ FIG 11C, 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.
[0085]
　Structural members 10 g, 10h, 10i shown in FIGS. 11A ~ FIG. 11C, both provided with a channel member 13 of the channel, the closing plate 2 is joined to the channel member 13. Channel member 13 shown in FIGS. 11A ~ FIG. 11C, a top wall 1a, two side walls 1br extending from both ends of the top wall 1a, a 1bh, channel member 13 and bonding the closing plate 2 two junctions 3r, equipped with a 3h. Two side walls 1br, 1bh is opposed to each other. Two junctions 3r, 3h are provided on a part and closing plate 2 and are superimposed portions of the channel member 13. Joint 3r, 3h, for example, a part of the spot welding or laser welding. If the joint is arranged in a discontinuous (intermittent) in the longitudinal direction (ridge line extending direction) of the channel member 13, 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. Top wall 1a and two side walls 1br, between 1bh are two first ridge 1Abr, there is 1Abh.
[0086]
　In channel-shaped member 13 shown in FIGS. 11A and 11B, 2 two side walls 1br, 1bh includes a first sidewall 1br and second sidewall 1bh. The one end portion of the top wall 1a side of the first side wall 1br other end of the opposite side is bent. Flange 1dr extends from the bent portion. Flange 1dr is superimposed and closing plate 2. Flange 1dr has a contact surface in contact with the closing plate 2. Flange 1dr and closing plate 2 are joined together at the junction 3r.
[0087]
　First sidewall 1br, the two first ridgeline 1Abr, located between one of the first ridge line 1Abr the flange 1dr of 1Abh. Between the flange 1dr a first sidewall 1br there is a second ridge 1Bdr. The second ridge 1bdr is an end portion of the flange 1DR. The second ridge 1bdr the first ridgeline 1Abr, extending in the longitudinal direction (y direction) of the same direction, that channel member 13 and 1Abh.
[0088]
　The height HR of the first sidewall 1br, the height of the first sidewall 1br in a direction perpendicular to the top wall 1a, i.e., the direction perpendicular to the top wall 1a of the first ridge line 1abr and second ridge 1bdr it is the distance in. Central 1midr in a direction perpendicular to the top wall 1a of the first sidewall 1br is the center of the first ridge line 1abr and second ridge 1bdr in a direction perpendicular to the top wall 1a.
[0089]
　Second sidewall 1bh are two first ridgeline 1Abr, located between the other of the first ridge line 1Abh and junction 3h of 1Abh. Second sidewall 1bh are not bent. Some joint 3h side of the second side wall 1bh, superimposed and closing plate 2. Some joint 3h side of the second side wall 1bh, having a contact surface 1dh that contacts the closing plate 2. Second sidewall 1bh extends in the same direction as the contact surface 1Dh.
[0090]
　The height HL of the second sidewall 1bh is the distance between the first ridge line 1abh and junction 3h in the direction perpendicular to the top wall 1a. Central 1midh in a direction perpendicular to the top wall 1a of the first sidewall 1bh is the center of the first ridge line 1abh and junction 3h in the direction perpendicular to the top wall 1a.
[0091]
　In channel-shaped member 13 shown in FIG. 11C, two side walls 1br, 1bh are two first ridgeline 1Abr, and 1Abh, two joints 3r, between 3h, respectively located. The height HR of the one side wall 1br of the two side walls is the distance in a direction perpendicular to the top wall 1a between the joint portions 3r and the first ridgeline 1Abr. The height of the other side wall 1bh of the two side walls HL is the distance in the direction perpendicular to the top wall 1a between the first ridge line 1abh and junction 3h.
[0092]
　In channel-shaped member 13 shown in FIGS. 11A ~ FIG 11C, each side wall 1br, 1bh includes low intensity regions 1sr, and 1SH, low intensity regions 1sr, the high intensity regions yield strength is higher than 1SH. Each side wall 1br, 1bh low intensity regions 1sr, 1SH, one end of each side wall (first ridge 1abr, 1abh), low intensity regions 1sr, the boundary between 1SH high strength region 1Skr, formed over 1skh that. Each side wall 1br, border from one end of 1bh 1Skr, distance in the height direction of each side wall to 1skh ShR, ShL is 20 to 40% of the height HR, HL of each side wall. Further, as shown in FIG. 11D, the low intensity regions 1sh, in the longitudinal direction (extending direction of the first ridge 1Abh) of the side wall 1bh, it is formed over the height HL or distance of the side wall 1bh. The low intensity regions 1sr, longitudinal width of 1sh, each sidewall 1br in FIGS 11A ~ FIG 11C, in any of 1bh, it sidewall 1bh, height 1bh HR, HL or more. Each side wall 1br, low intensity regions 1sr in 1bh, yield strength of 1sh, each sidewall 1br, 1bh the height direction definitive central position 1Midr, 60 to 85% of the yield strength of 1Midh.
[0093]
　That is, each side wall 1br shown in FIGS. 11A ~ FIG 11C, the low intensity regions of 1bh 1sr, 1SH, in the height direction of the side wall, the first ridgeline 1Abr, from 1Abh, each side wall 1br, height 1bh HR, provided to a distance of 20 to 40% of the HL. First ridge line 1Abr, the extending direction of 1abh in (sidewall 1br, longitudinal 1bh), the low intensity regions 1sr, 1SH, each sidewall 1br, provided over the height HR, HL or distance 1bh.
[0094]
　In the example shown in FIG. 11A, a first side wall 1br and second sidewalls 1bh are parallel to each other. In contrast, in the example shown in FIG. 11B, first side wall 1br and second sidewalls 1bh are not parallel to each other. In the example shown in FIG. 11B, first side wall 1br and second sidewalls 1bh is the distance from the top wall 1a, and extends so that the distance therebetween becomes large. In this example, the first side wall 1br extend in a direction perpendicular to the top wall 1a. Second sidewall 1bh extends in a direction having an angle with respect to the axis perpendicular to the top wall 1a. Flange 1dr extends outwardly from the other end portion of the closing plate 2 side of the first side wall 1br. Structural members having a cross section as shown in FIG. 11A, for example, can be applied to the A-pillar.
[0095]
　In the example shown in FIGS. 11A and 11B, closing plate 2 has a bent portion that is bent out of plane. The extending direction of the ridge 2abh formed in the bent portion of the closing plate 2 is the same as 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 1bh . The extending direction of 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 line 1Abh. (See FIG. 11D).
[0096]
　In the example shown in FIG. 11C, 2 two side walls 1br, 1bh are both not bent. That is, the contact surface 1dr sidewall 1br is in contact with the closing plate 2, extend in the same direction as the side wall 1br. Contact surface 1dh sidewall 1bh is in contact with the closing plate 2, extend in the same direction as the side wall 1bh.
[0097]
　Closing plate 2 comprises two contact portions 2br contacting is superposed with channel member 13, 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, the ridgeline is formed between the 2bh 2Abr, the extending direction of the 2abh, each sidewall 1br, contact surfaces 1dr that contacts the closing plate 2 in 1bh, 1Dh each sidewall 1br, is the same as the extending direction of the boundary line between the surface not in contact with the closing plate 2 in 1bh.
[0098]
　Figure 11A ~ FIG 11C are shown structural member 10 g, 10h, also in 10i, the same effect as the structural member 10 shown above in FIG. 1A ~ FIG 1C is obtained. The bonding section 3r, 3h is not limited to the portion of the weld. For example, fasteners such as screws, adhesive, or a wax such as brazing may be joint.
[0099]
　[Embodiment 2]
　Embodiment 2 relates to the third configuration. 12A is a cross-sectional view of a structural member of the present embodiment, FIG. 12B is a plan view of the structural member shown in FIG. 12A, FIG. 12C is a side view of the structural member shown in FIG. 12A.
[0100]
　Structural member 10j shown in FIGS. 12A ~ FIG. 12C, the low intensity regions 1s is, the other end portion of the closing plate 2 side of each side wall 1b (second ridge 1bc), the distance Sh in the height direction of each side wall 1b position to, and is formed at a height H above the width of the side wall 1b in the longitudinal direction. This can increase the impact energy absorbing efficiency of the case where impact is applied to the closing plate 2.
[0101]
　Structural member 10j shown in FIGS. 12A ~ FIG 12C includes a hat member 1, the closing plate 2 which is joined to the hat member 1. As shown in FIG. 12A, the hat member 1 has a top wall 1a, extending from both ends of the top wall 1a, a two side walls 1b which are opposed to each other, two from each side wall 1b, the two flanges 1c extending in opposite directions outwardly equipped with a. Two flanges 1c is bonded to the closing plate 2.
[0102]
　In hat material 1 of the structural member 10j, between the top wall 1a and two side walls 1b is bent. The bent portion between the top surface portion 1a and two side walls 1b, respectively, two first ridgeline 1ab is formed. Between two flanges 1c and two side walls 1b is bent, respectively. The bent portion between the two flanges 1c and two side walls 1b, respectively, two second ridge 1bc is formed. Each of the two side walls 1b will be located between the first ridge line 1ab and second ridge 1bc.
[0103]
　As shown in FIG. 12C, the extending direction of the second ridgeline 1ab is the same as the longitudinal direction of the structural member 10j. Longitudinal direction of the structural member 10j is also the longitudinal direction of the side wall 1b, is also the longitudinal direction of the top wall 1a. In the example shown in FIG. 12C, the extending direction of the second ridgeline 1ab is the same as the extending direction of the first ridge line 1ab.
[0104]
　In hat member 1a shown in FIGS. 12A ~ FIG 12C, each side wall 1b includes a yield strength than the low-strength region 1s and a low intensity region 1s high strength region. Low intensity region 1s of each side wall 1b, the other end portion of the closing plate 2 side of each side wall 1b (second ridge 1bc), is formed over the boundary 1sk the low intensity region 1s and high intensity regions. Distance Sh in the height direction of each side wall 1b of the other end portion of each side wall 1b (second ridge 1bc) to the boundary 1sk is 20 to 40% of the height H of each side wall 1b. Further, as shown in FIG. 12C, the low-strength region 1s, in the longitudinal direction (extending direction of the first ridge line 1ab) of the side wall 1b, it is formed over a distance of more than the height H of the side wall 1b. That is, in the longitudinal direction of the width of the side wall 1b of the low intensity region 1s is greater than the height H of the side wall 1b. Yield strength of the low intensity region 1s at each side wall 1b is 60 to 85% of the yield strength of the high strength region in the height direction definitive central position 1mid of each side wall 1b.
[0105]
　In other words, the low intensity regions 1s of each side wall 1b shown in FIGS. 12A ~ FIG. 12C, in the height direction of the side wall 1b, the second ridge 1bc, distance 20-40% of the height H of each side wall 1b to be provided. In the extending direction of the second ridgeline 1bc (longitudinal direction of the side wall 1b), low intensity region 1s are provided over the height H above the distance of each side wall 1b.
[0106]
　In the present embodiment, the height direction of the side wall 1b is a direction perpendicular to the closing plate 2. The direction perpendicular to the closing plate 2, in particular, a direction perpendicular to the plane of the surface of the closing plate 2. Closing plate 2 protrusions, recesses, if having a stepped or curved portion, and a direction perpendicular to the virtual plane connecting the two second edges 1bc, and the direction perpendicular to the closing plate 2. The height H of each side wall 1b is the same as the distance between the first ridge line 1ab and second ridge 1b in a direction perpendicular to the closing plate 2.
[0107]
　In structural members 10j of this embodiment, for example, deformation behavior when a shock is applied in the z direction closing plate 2 becomes likely to collapse cross section shown in FIG. As a result, it is possible to reduce the degree of bending deformation in the direction perpendicular to the closing plate 2. Thus, the structural member 10j is when impacted can absorb greater impact energy in a small deformation. In other words, the structural member 10j can absorb the impact energy efficiently.
[0108]
　The distance Sh low intensity region 1s is more preferable to be more than 35% of the height H of the side wall 1b, the I 30% still preferred. The distance Sh is more preferably a more than 25% of the height H of the side wall 1b. And intensity of the low-strength region 1s of the side wall 1b, the ratio of the intensity of the height direction central position 1Mid (intensity ratio) is preferable to be 83% or less, more preferably 80% or less. Also, the intensity ratio is more preferably a 70% or more.
[0109]
　Modification of the first embodiment can be applied also to the second embodiment.
[0110]
　In the above embodiments 1 and 2, at least one of the first ridge and the second ridge can be curved. For example, at least one of the first ridge and the second ridge may be curved in the height direction of the side wall may be curved in a direction perpendicular to the side walls. Further, the side wall height (distance between the first ridge and the second ridge) may be altered in the longitudinal direction (extending direction of the first ridge). If the height of the side wall are different by a longitudinal position, the height of the side walls as the height direction of distances Sh and standards longitudinal distance Sn low intensity regions of the side wall at the portion where the low intensity regions are formed the average value of the height.
[0111]
　[Application to vehicle Example
　above embodiment 1 of the structural member 10 (structural member 10e, 10e2,10e3,10g, 10h, 10i including other modification. Hereinafter, the same) even vehicle equipped with, embodiments of the present invention include. In the vehicle, the structural member 10, top wall 1a is on the outside of the vehicle, it is possible to closing plate 2 are arranged so that the inside of the vehicle. In other words, the structural member 10 is attached to the impact input surface is on the outside of the vehicle. Thus, in the event of an impact from the outside of the vehicle, the degree of structural member 10 protrudes into the inside of the vehicle is reduced. Therefore, the possibility of structural member 10 is in contact with the device also people in the vehicle becomes lower. For example, structural members, it is avoided that break towards the room at the time of collision. As a result, safety is further improved.
[0112]
　Vehicle including a structural member 10j of the second embodiment of the above should also be included in embodiments of the present invention. In the vehicle, the structural member 10j is top wall 1a is inside the vehicle, it is possible to closing plate 2 are arranged so as to be outside of the vehicle. In other words, the structural member 10j is attached to the impact input surface is on the outside of the vehicle. Thus, in the event of an impact from the outside of the vehicle, the degree of structural member 10 protrudes into the inside of the vehicle is reduced.
[0113]
　Furthermore, the structural member 10,10j may also be used in a state supported at two points spaced longitudinally. In this case, the structural member 10,10j has two connecting portions is a portion coupled to the other member. That is, structural members 10,10j is supported on the other member in the connecting portion. Connecting portion may also be referred to as support. Connecting portion, side wall 1b, is provided on at least one top wall 1a and closing plate 2.
[0114]
　The coupling portion, structural member 10,10j is fixed to the other member. Connection of structural members 10,10j, for example, is joined to another member by fastening members or welding. The connecting portion may be three or more.
[0115]
　The connecting portion is in a state of being inserted into the internal space of the structural member 10,10J, it may be configured to support a structural member 10,10J. For example, in the case of a structural member 10, opened a through-hole in the closing plate 2, by inserting the other member from the through hole, it may be joined to the end portion of the other member on the inner surface of the top wall 1a. Thus, it may be provided with a connecting portion to the member inside the top wall 1a of the structural member 10. For structural members 10j, opened a through hole in the top wall 1a, by inserting the other member from the through hole, it may be joined to the end portion of the other member on the inner surface of the closing plate 2. Thus, it may be provided with a connecting portion to the member inside the closing plate 2 of the structural member 10j.
[0116]
　Low intensity regions 1s is preferably provided between the two connecting portions. In other words, at least a part of the low-strength region 1s is formed preferably on the side wall 1b between the two connecting portions. Thus, it is possible to reduce the bending deformation when an impact is applied to a portion of the structural member that is not supported by the connecting portion. The low intensity regions 1s is preferably provided in the middle of the two connecting portions. That is, the side wall 1b at the center of the two connecting portions, it is preferable that the low intensity regions 1s is formed. This can increase the impact energy absorbing efficiency of the high strong impact likely to take positions. As a result, it is possible to reduce the degree of bending deformation of the structural member due to impact.
[0117]
　Further, it is desirable to place a low intensity region 1s in the longitudinal center of the structural member 10,10J. The reason for this is as follows. Structural members 10,10j may be connected to the other member in the vicinity of both end portions away from the longitudinal center. Thus, in either case with and without coupling part there is also the structural member 10,10J, becomes maximum frangible portion moment due impact (middle point between the longitudinal center or connecting portion of the structural member) it is possible to suppress the bending of the deformation effectively.
[0118]
　Thus, structural members 10,10j can be used in the vehicle structural member of high strength. The structural member for a vehicle, for example, A-pillar, B-pillar, side sill, roof rail, the floor members, the members constituting the vehicle body such as a front side member, and, attached to the vehicle body such as door impact beams or bumper, the impact from the outside It includes members protect the equipment and passenger in the vehicle. The vehicle structural member to absorb impact energy during collision of the vehicle.
[0119]
　Figure 13 is a diagram showing an example of the structure member disposed on the vehicle. In the example shown in FIG. 13, A-pillar 15, B-pillar 16, side sill 17, roof rail 18, the bumper 19, a front side member 20, the door impact beam 21, and the floor member 22, using the rear side member 23 is a structural member for a vehicle It is. At least one of these vehicle structural member may be provided with low-strength region 1s as described above in the structural member 10,10J.
[0120]
　Figure 14 is a diagram showing a B-pillar 16, which is constituted by a structural member in the present embodiment. In the example shown in FIG. 14, B-pillar 16, similarly to the structural member 10 includes top wall 16a, a pair of side walls 16b, a pair of flanges 16c and closing plate (not shown). Top wall 16a of the B-pillar 16 is arranged on the outside of the vehicle. A pair of side walls 16b from both ends in the direction perpendicular to the longitudinal direction of the top wall 16a extending opposite to each other. The one end of the top wall 16a of the side wall 16b flange 16c from the other end of the opposite side is formed to extend. The top wall 16a of the flange 16c side opposite, i.e. the inner surface of the vehicle, closing plate (not shown) is bonded. Low intensity region 16s is provided in a portion of the top wall 16a of the side wall 16b. Low intensity regions 16s from the boundary of the top wall 16a and side walls 16b (shoulder), is provided in the region up to a position at a distance of 20-40% of the height of the side wall 16b. Yield strength of the low-strength region is 60-85% of the yield strength of the other region (yield strength in the height direction central position of the sidewall 16b).
[0121]
　Vehicle structural member to absorb the impact energy can be roughly divided into two types of things to be deformed bending shall be axial compression deformation. Those which bending deformation absorbs the impact energy by folding and sectional collapsing deformation. B-pillar, members such as the side sill is required to enhance the impact energy absorption efficiency by using a high strength material. Therefore, the structural member 10 of the present embodiment, the ultra high strength steels of a tensile strength in the height direction central position 1mid sidewall 1b (tensile strength in the region other than the low strength areas) or 980 MPa (or yield strength 500 Mpa) Once applied, the above effect appears remarkably. Further, it is possible to the strength of the center position 1mid sidewall 1b of the structural member 10 (the intensity of a region other than the low-intensity regions 1s), a tensile strength by the above 1 GPa, exhibits more effect.
[0122]
　The structure member 10,10j is not limited to four-wheel vehicle such as an automobile shown in FIG. 13, for example, can be used as a structural member of the two-wheel vehicle. Also, application of the structural member 10,10j is not limited to a vehicle. For example, a container having an impact resistance, a building, a ship, or, as a structural member of an aircraft or the like, can be used structural member 10,10J.
[0123]
　[Production Process]
　structural member 10,10j may be formed entirely of the same material. Structural members 10,10j, for example, can be formed of steel plate. The manufacturing process of the structural member 10,10J, a process of forming a hat member 1 having a low intensity region 1s (or channel member 13), a process of forming a 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.
[0124]
　A method of forming a low intensity region 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 intensity regions. Further, after the strengthening entire hat member 1 by performing quenching, it can also be performed partially annealed to form a low-intensity region.
[0125]
　Alternatively, it is also possible to produce structural member 10,10j with hot pressing (hot stamping) technology. In the step of hot pressing, the conditions of the heating or cooling by causing partially different in the mold, 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.
[0126]
　The manufacturing method of the structural member 10,10j is not limited to the above example. For example, it is possible to tailored blank, etc., using other known methods, to form the structural member 10,10j having a low intensity region 1s.
Example
[0127]
　In this embodiment, the analysis of the deformation of the structural member when colliding the indenter to a structural member having a hat member and the closing plate in the simulation. 15, the configuration of the analysis model in the simulation is a diagram schematically illustrating. In this simulation, in a state of bridging the structural member 30 into two pedestal 120, the central portion in the longitudinal direction of the structural member 30, the indenter 110, and analyzed the deformation behavior when colliding. The radius of curvature of the indenter 110 and 150mm, the initial velocity of the indenter was set to 4m / sec. Mass of indenter 110 was set to 350 kg.
[0128]
　Figure 16 is shows the respective dimensions in a cross section perpendicular to the longitudinal direction of the structural member 30 used in the simulation. Structural member 30 is provided with a hat member 3 and the closing plate 4. Hat member 3 has a top wall 3a, a pair of side walls 3b, and a pair of flanges 3c. A pair of side walls 3b extend from both ends of the top wall 3a, facing each other. A pair of flanges 3c, in each pair of side walls 3b, the one end portion of the top wall 3a of the side wall 3b extending from the other end opposite to the opposite direction outside of the pair of side walls 3b. Closing plate 4 is fixed to a pair of flanges 3c. Each of the pair of side walls 3b, meanwhile in the region from the end portion up to the position of the distance Sh, it has a low intensity region 3s.
[0129]
　In Figure 16, H = 50mm, W1 = 50mm, W2 = 65mm, W3 = 40mm, and the t = 1.4 mm. By changing the distance Sh low intensity region 3s, it was crash simulation. Further, the low-strength region 3s, by varying the intensity of the other areas, was carried out crash simulation. Incidentally, half the length of the longitudinal width of the low intensity region 3s SL (see FIG. 15) was set to H / 2.
[0130]
　17, as Sh = (2/5) H, when inputting the impact load by changing the intensity ratio of the low intensity region 3s and other regions, is a graph showing the deformation amount due to bending deformation. 17, the vertical axis represents the amount of intrusion structural member in a direction perpendicular to the top wall 3a (z-direction) (the amount of protrusion). The horizontal axis shows the ratio of intensity of other high intensity regions of the strength of the low strength areas 3s (= height direction central position of the side wall 3b) (intensity of the intensity / high intensity regions of the intensity ratio = low intensity region) . In the graph of FIG. 17, a plot of diamonds, the yield strength of the high strength region shows the results of a 120 kgf, square plots show the results when the yield strength of the high strength region was 145Kgf.
[0131]
　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 has a collapsed section shown in FIG. In this interval, if the intensity of the low intensity region is low (less intensity ratio of 0.60), although become deformed collapse section, large intrusion volume, substantially the same as the amount of intrusion when the intensity ratio exceeds 0.85 It became. 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 collapsed section shown in FIG. 4, presumably because changes to break shown in FIG. Thus, deformation bent to the intensity of the low-strength region is too high (the intensity ratio is high), push-in amount is increased. From the results of FIG. 17, 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%.
[0132]
　Table 1 below (the yield strength of the low intensity regions, YP100MPa, the yield strength of the other area, YP120MPa) the intensity ratio 0.83 and, the deformation behavior in the case of changing the distance Sh low intensity regions show. In Table 1, up arrow represents the same value as the field immediately above. Round of deformation behavior column (○) shows a collapsed cross-sectional shown in FIG. 4, cross (×) shows the bending shown in FIG.
[0133]
[Table 1]

[0134]
　The results shown in Table 1, the case without the low intensity regions (Sh = 0), (50% of Sh is H) Sh = H / 2, and, Sh = H / 10 (10% of Sh is H) If the deformation behavior became broken (see FIG. 3). Sh = 2H / 5 (40% of Sh is H), (about 33% Sh is H) Sh = H / 3, and, in the case of Sh = H / 5 (20% of Sh is H), deformation behavior became sectional collapse (Fig. 4). From this result, the distance Sh from one end of the top wall 3a of the side wall 3b of the low intensity region 3s, by 20 to 40% of the height H of the side wall 3b, the deformation behavior as crushing section, intrusion it was confirmed that the reduced amount.
[0135]
　Further, by changing the longitudinal dimension SL of the surface and low intensity regions 3s colliding indenter 110, a simulation was performed. 18, the configuration of the analysis model in the simulation is a diagram schematically illustrating. In the model shown in FIG. 18, the structural member 30, under the hat member 3, closing plate 4 to be positioned above, to be stretched two pedestal 120. The longitudinal center of the structural member 30 is positioned in the middle of the two pedestal 120. The longitudinal center of the closing plate 4, the indenter 110 collide. In the model shown in FIG. 18, each of the pair of side walls 3b is a region ranging from the other end portion of the closing plate 4 side at a distance Sh, it has a low intensity region 3s.
[0136]
　Model impinging indenter 110 of the hat member shown in FIG. 15 (hereinafter, referred to as a forward hat model) and, for both the model (hereinafter, referred to as reverse hat model) impinging indenter 110 in closing plate 4 shown in FIG. 18 simulation was carried out. Changing Specifically, in each of the forward-hat model and inverse hat model, the dimensions Sh = H / 3 in the height direction of the low-strength region 3s, and the longitudinal dimension SL, with SL = 0, H / 2, H It was analyzed Te. In other words, a simulation was performed under the following conditions case1 ~ case6.
　case1: forward hat, SL = 0, Sh = 0 ( no low-strength
　region) case2: forward hat, SL = H / 2, Sh
　= H / 3 case3: forward hat, SL = H,
　Sh = H / 3 case4: Conversely hat, SL = 0, Sh = 0 ( no low-strength
　region) case2: reverse-hat, SL = H / 2, Sh
　= H / 3 case3: reverse-hat, SL = H, Sh = H / 3
[0137]
　19 and 20 are graphs showing the analysis results of the case1 ~ case 6. Figure 19 is a load of case1 ~ case3 forward hat model - is a graph of stroke line (F-S line). Figure 20 is a load of case4 ~ case 6 opposite hat model - is a graph of stroke line (F-S line). In the analysis results of FIG. 19, case3, compared to case1, case2, lowering of the load is slow. In the analysis results of FIG. 20, case 6, as compared to the case4, case5, lowering of the load it is slow. The conditions of the case3 and case 6, is considered a load for bending are suppressed continues. From this, in any order hat model and reverse-hat model, the longitudinal width of the low intensity region 3s, who was the height H of the side wall, rather than the H / 2, the impact energy absorption efficiency high, I was found to be inhibited.
[0138]
　Figure 21 shows the results of analysis of the deformation behavior of the case1 ~ case3. Figure 22 shows the results of analysis of the deformation behavior of case4 ~ case 6. 21 and 22, the stroke indicates the deformation of the structural member when the 20 mm. In case1 ~ analysis of case3 forward hat model shown in FIG. 21, when the case3 where the SL = H, as compared with the case2 where a case1 and SL = H / 2 which is the SL = 0, deformation longitudinally spread bending is suppressed. In case4 ~ analysis of case6 reverse hat model shown in FIG. 22, when the case6 where the SL = H, as compared with the case of case5 which was case4 and SL = H / 2 which is the SL = 0, deformation longitudinally spread bending is suppressed.
[0139]
　Indeed, to produce the same specimen and the structural member shown in FIG. 15, an experiment was conducted to add an impact. The specimen, the two base arranged at a distance from each other in the longitudinal direction of the test body, Ki mounting to the closing plate and evaporated to collide the indenter (falling weight) hat member. Mass of the indenter is set to 376Kg, the impact velocity of the indenter was 3.9 m / s. And the structural member of the intensity uniform, the two structural members having a low intensity region in a part, prepared as test specimens, an impact was applied by the indenter to each. Low intensity regions, to the position of the distance Sh in the height direction from the end portion of the top wall side of the side wall, provided over a distance LS in the longitudinal direction of the side wall. Here, the distance Sh = 0.3H (30% of the height H of the side wall), the distance LS = was H (height H of the side wall).
[0140]
　23, intensity is a view showing a modification results in uniform specimen. Figure 24 is a diagram showing a modified result of the test specimen having a low intensity region in a part. Test body shown in FIG. 23, broken has occurred. Test body shown in FIG. 24 has a deformation of the crushed section. Write specimens having a low intensity regions, degree of deformation due to impact is reduced.
[0141]
　Figure 25 is a graph showing the measurement result of the impact experiment specimens having a low intensity region in a part, and an analysis result of simulation using the model of the same structural member as a test sample. Graph of Figure 25, the horizontal axis, impactor - indicates (indenter) displacement (mm), the vertical axis represents load (kN). In the graph, a thin line shows the experimental results, showing the bold line analysis results. From the results shown in FIG. 25, the analysis result of the simulation, it was found that has become close to experimental results.
[0142]
　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
[0143]
　1: hat member
　1a: top wall
　1b: sidewall
　1c: Flange
　1s: low intensity region
　2: closing plate
　10: structural member
The scope of the claims
[Claim 1]
　And closing plate,
　and a hat member,
　　said hat member,
　　and top wall,
　　a pair of flanges provided in contact with the closing plate,
　　extending from both ends of the top wall, a pair of side walls facing each other , with one end portion of the top wall side, wherein a second end portion of the one end portion and the opposite side, and the other end portion the pair of flanges extending to the opposite direction outside of the pair of side walls, a pair of side walls When provided with,
　each of said pair of sidewalls, a high strength region comprising a center of the side wall in a direction perpendicular to said top wall, low intensity from 60 to 85% of the yield strength of the yield strength of the center of the side wall and a region, the low-strength region, in a direction perpendicular to said top wall, to the one toward the end to the other end of the distance of 20-40% of the height of the sidewall position of the side wall until, or The in the longitudinal direction of the side wall, it is formed over the height over a distance of said side wall, structural member.
[Claim 2]
　At least one closing plate,
　and a hat member,
　said hat member,
　　a top wall
　　and two first ridgeline on the both ends of the top wall,
　　the two flanges, each being joined to the closing plate When,
　　two second edges at the ends of the two flanges,
　　between said two first edges and said two second edges, and two side walls located respectively,
　the 2 one of each of the sidewalls,
　the direction from the first ridgeline on the second ridge, up to 20-40% of the distance between the first ridge and the second ridge line in a direction perpendicular to the top wall and wherein the extending direction of the first ridge, provided over the length of the region having a distance between said second ridge and said first ridge line in a direction perpendicular to said top surface, perpendicular to the top wall central breakdown of the side wall in such direction Having a yield strength of from 60 to 85% of the time, comprises a low intensity regions, structural members.
[Claim 3]
　At least one closing plate,
　and a hat member,
　said hat member,
　　and top wall,
　　said top wall and two first ridge at each end portion,
　　two, each joined to the closing plate a flange,
　　wherein the two second edges at the ends of the two flanges,
　　provided between said two first edges and said two second edges, and two side walls positioned respectively,
　wherein each of the two side walls,
　wherein the second ridge line toward the first ridgeline, 20-40% of the distance between said second ridge and said first ridge line in a direction perpendicular to the closing plate up, and in the extending direction of the second ridge is provided over the length of the region the distance between the first ridge and said second ridge in a direction perpendicular to the closing plate, the closing pre Having a yield strength of from 60 to 85% of the yield strength of the center of the side wall in a direction perpendicular to bets, comprises a low intensity regions, structural members.
[Claim 4]
　At least one closing plate,
　and a channel member,
　said channel member includes
　　a top wall,
　　and two first ridgeline on the both ends of the top wall,
　　and said channel member and said closing plate and two joints for joining,
　　between the two first edges and said two junctions, and two side walls positioned respectively,
　each of said two sidewalls,
　said first ridge toward the junction from the first ridge line in a direction perpendicular to said top wall and to 20 to 40% of the distance between the joint portion and the extending direction of said first ridge, said top surface portion provided above the length of the region the distance between the first ridge line and the junction in a direction perpendicular 60 to 85% of the yield of the yield strength of the center of the side wall in a direction perpendicular to the top wall having a strength, and a low intensity region, structure .
[Claim 5]
　At least one closing plate,
　and a channel member,
　said channel member includes
　　a top wall,
　　and two first ridgeline on the both ends of the top wall,
　　a flange is joined to said closing plate ,
　　a second ridge at the end of the flange,
　　and a joint portion for joining the flange other than the portion of the channel member and the said closing plate,
　　one and the second of said two first ridgeline a first side wall located between the ridge comprises a first low-strength region, the first low-strength region, toward the second edge line from the first ridge, the and said first ridge line in a direction perpendicular to the top wall until 20-40% of the distance between the second ridge, and in the extending direction of the first ridge, said in a direction perpendicular to the top wall the first ridge and above the distance between the second ridge It provided the length of the region, having a yield strength of from 60 to 85% of the yield strength of the center of the side wall in a direction perpendicular to said top wall, a first side wall,
　　the other of said two first ridgeline a second side wall located between said junction comprises a second low-strength region, the second low-strength region, toward the junction from the first ridge, the and said first ridge line in a direction perpendicular to the top wall until 20-40% of the distance between the joint portion and the extending direction of the first ridge, said in a direction perpendicular to the top wall first provided over the length of the region having a distance between the ridge and the junction, having a yield strength between 60 and 85% of the yield strength of the center of the side wall in a direction perpendicular to said top wall, a second side wall the provided structural member.
[Claim 6]
　The low intensity region, the are arranged in the longitudinal center of the side wall, structural member according to any one of claims 1 to 5.
[Claim 7]
　Said top wall or said closing plate, the comprising at least two connecting portions is connected to another member in a position separated from one another in the longitudinal direction of the side wall,
　the low intensity region, said at least two in the longitudinal direction of the side wall one of the centrally disposed between the connecting portions a structure according to any one of claims 1 to 6.
[8.]
　In each of the two side walls, the center of the tensile strength of the side wall in a direction perpendicular to said top surface is above 980 MPa, structural member according to any one of claims 1, 2, 4, and 5 .
[Claim 9]
　In each of the two side walls, the center of the tensile strength of the side wall in a direction perpendicular to the closing plate is more than 980 MPa, structural member according to claim 3.
[Claim 10]
　A vehicle comprising a structural member according to any one of claims 1, 2, 4, and 5,
　wherein the structural member is on the outer side of said top surface said vehicle, said closing plate on the inside of the vehicle is arranged so that a vehicle.
[Claim 11]
　A vehicle comprising a structural member according to claim 3,
　wherein the structural member, wherein the closing plate on the outside of the vehicle, wherein the top wall is disposed so that the inside of the vehicle, the vehicle.