The present invention relates to a vehicle bumper beam and a bumper beam for a vehicle is mounted. More particularly, to a motor vehicle bumper beam and the bumper beam for an automobile is mounted.
BACKGROUND
[0002]
　The inside of the vehicle bumper, the bumper beam is provided. A collision load when the collision is borne to the bumper beam, in order to ensure the safety of the vehicle. Recently, CO 2 from the viewpoint of the reduction and fuel efficiency, it is required to reduce the weight of the bumper beam. To reduce the weight of the bumper beam, while thinner the thickness of the bumper beam, it is necessary to improve the strength of the bumper beam.
[0003]
　Bumper beam of high strength, for example, JP-A 7-309184 (Patent Document 1), JP-A-6-328988 (Patent Document 2), Japanese Patent 6-171441 (Patent Document 3) and Japanese Patent 2011 -111074 discloses disclosed in (Patent Document 4).
[0004]
　In the bumper beam disclosed in Patent Document 1, the space of the box-shaped formed by a plurality of members that are joined, the reinforcement member is disposed. Reinforcing member along the longitudinal direction of the vehicle. Thus, the strength of the bumper beam as compared with the conventional bumper beam are equivalent, and it is possible to realize the weight and cost, and is described in Patent Document 1.
[0005]
　Bumper beam disclosed in Patent Document 2, to form a box-shaped cross-section, having a reinforcing member on the inside of the box-shaped cross-section. Reinforcing member, along the vertical direction of the vehicle. Accordingly, when a load is applied in the longitudinal direction of the vehicle, the deformation of the outer upper wall and the lower wall portion is suppressed. Thus, the strength of the bumper beam is improved, and is described in Patent Document 2.
[0006]
　Bumper beam disclosed in Patent Document 3, forms a box-shaped cross-section in combination hat-shaped press-formed article has a reinforcing member to the interior space. Reinforcing member, along the vertical direction of the vehicle. This improves the strength of the bumper beam and the deformation of the bumper beam is suppressed, and is described in Patent Document 3.
[0007]
　Bumper beam disclosed in Patent Document 4 includes a front reinforcing member, and a rear reinforcing member. Front reinforcing member includes a front groove recessed toward the rear side from the front side of the bumper beam. Rear reinforcement includes a rear groove recessed toward the rear side from the front side of the bumper beam. Front groove is fitted in the rear groove. Thereby, the energy absorption characteristics of the bumper beam is improved, and is described in Patent Document 4.
CITATION
Patent Document
[0008]
Patent Document 1: JP-A-7-309184 JP
Patent Document 2: JP-A 6-328988 Patent Publication
Patent Document 3: JP-A 6-171441 Patent Publication
Patent Document 4: JP 2011-111074 JP
Summary of the Invention
Problems that the Invention is to Solve
[0009]
　However, the bumper beam of Patent Documents 1 to 3, to ensure the safety of the vehicle, provided with a reinforcing member. Therefore, the bumper beam of Patent Documents 1-3 is heavy. Rear stiffener of the bumper beam in Patent Document 4 includes a rear groove. Therefore, amount of the rear groove wall, the bumper beam of Patent Document 4 is heavy.
[0010]
　An object of the present invention is to provide a bumper beam of high light intensity vehicle.
Means for Solving the Problems
[0011]
　Bumper beam for a vehicle according to an embodiment of the present invention includes a first member, a second member. The first member includes a first top plate portion, a first vertical wall portion of the two, and the two first flanges of the. The first top plate portion is flat in cross section perpendicular to the longitudinal direction of the first member. The first vertical wall portion of the two leads to respective side portions of the first top plate portion. The first flange portion of the two leads to the first vertical wall portion each of the two. The second member includes a second top plate, a second vertical wall portion of the two, and two second flange portions. The second top plate portion has a protrusion protruding toward the opposite side of the first top plate portion. Two second vertical wall portion, leading to respective opposite sides of the second top panel section. The second vertical wall portions of the two are opposed closely inside the first member to each of the first vertical wall portion. The second flange portion of the two is arranged to be joined to the first flange portion respectively connected to each of the two second vertical wall portion.
The invention's effect
[0012]
　Bumper beam according to the present invention, light intensity is high.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013]
[1] Figure 1 is a cross-sectional view of a bumper beam of the present embodiment.
FIG. 2 is a cross-sectional view of a bumper beam of the case 1.
FIG. 3 is a cross-sectional view of a bumper beam of the case 2.
[4] FIG. 4 is a diagram showing the deformation behavior of the bumper beam of the case 1 is a diagram showing the initial state.
FIG. 5 is a diagram showing a state where the deformation has progressed from the state shown in FIG.
FIG. 6 is a diagram showing a further state of deformation has progressed from the state shown in FIG.
FIG. 7 is a load of cases 1 and 2 - is a deflection diagram.
[8] FIG. 8 is a diagram showing the deformation behavior of the bumper beam schematically.
[9] FIG. 9 is a plan view of the bumper beam.
[10] FIG 10 is a diagram showing a bumper beam of the present invention Example 1.
[11] FIG 11 is a diagram showing a bumper beam of the reference example.
[12] FIG 12 is a diagram showing a bumper beam of Comparative Example 1.
FIG. 13 is a load of the bumper beam of Example 1 - a deflection curve.
[14] FIG 14 is a diagram showing the angle of the convex portion of the bumper beam of Example 5.
[15] FIG 15 is a diagram showing a bumper beam of Comparative Examples 2-5.
DESCRIPTION OF THE INVENTION
[0014]
　Herein, "longitudinal direction" of members constituting the bumper beam, means a vehicle width direction when the bumper beam is attached to the front or rear of the vehicle. As used herein, "length" relates members constituting the bumper beam, it means a longitudinal distance of the target member. As used herein, "width" about members constituting the bumper beam, means the distance of the vehicle height direction when the bumper beam is attached to the front or rear of the vehicle. In the present specification, the "height" for members constituting the bumper beam, means the distance vehicle length direction when the bumper beam is attached to the front or rear of the vehicle.
[0015]
　In the present specification, the "maximum permissible load" means the maximum load that the bumper beam is loaded on the bumper beam when buckled.
[0016]
　(1) bumper beam for a vehicle according to the present embodiment includes a first member, a second member. The first member includes a first top plate portion, a first vertical wall portion of the two, and the two first flanges of the. The first top plate portion is flat in cross section perpendicular to the longitudinal direction. The first vertical wall portion of the two leads to respective side portions of the first top plate portion. The first flange portion of the two leads to the first vertical wall portion each of the two. The second member includes a second top plate, a second vertical wall portion of the two, and two second flange portions. The second top plate portion has a protrusion protruding toward the opposite side of the first top plate portion. Two second vertical wall portion, leading to respective opposite sides of the second top panel section. The second vertical wall portions of the two are opposed closely inside the first member to each of the first vertical wall portion. The second flange portion of the two is arranged to be joined to the first flange portion respectively connected to each of the two second vertical wall portion.
[0017]
　The bumper beam of this embodiment, the second vertical wall portion of the second member disposed opposite to the first vertical wall portion of the first member. In this case, when a collision load acts on the bumper beam, the deformation of the first member and the second member to suppress. Further, since the second top plate portion has a convex portion, the collision load to the bumper beam is loaded, a region other than the convex portion of the second top plate portion moves deformed toward the first vertical wall portion . Therefore, deformation of the bumper beam inside of the first vertical wall portion is suppressed. Thus, the strength of the bumper beam of this embodiment, higher even without additional reinforcing member. Thus, the bumper beam of this embodiment has a high strength light weight.
[0018]
　(2) In the bumper beam according to the above (1), the height h1 of the second vertical wall portion ratio h1 / H between the height H of the first vertical wall portion, 0.1 or more, 0.5 or less in it is preferred.
[0019]
　In the bumper beam according to (3) above (1) or (2), a first vertical wall portion clearance between the second vertical wall portion, 0 mm or more, preferably 10mm or less.
[0020]
　(4) In the bumper beam according to the above (1) to (3), the width w1 of the convex portion of the second top panel section ratio w1 / W of the width W of the first top plate portion is 0.1 or more , 0.7 or less, and the height h2 of the projecting portion of the second top panel section ratio h2 / h1 between the height h1 of the second vertical wall portion of the second member, at least 0.5, 1.1 in is preferably less.
[0021]
　(5) In the bumper beam according to the above (1) to (4), a first flange portion and the second flange portion is welded, adhesive, rivets, or preferably are joined by these combination.
[0022]
　(6) In the bumper beam according to the above (1) to (5), first and second members is made of steel sheet, the tensile strength of the steel sheet is preferably at least 1 GPa.
[0023]
　(7) (1) above the first flange portion and the joint portion of the second flange portion of the bumper beam according to (6), from the first vertical wall portion side of the edge of the first flange portion to a region within 15mm preference is provided is. More joint away from the first vertical wall portion, the second member tends to plane deformation, because the effect of suppressing the deformation of the first vertical wall portion is lowered.
[0024]
　(8) above (1) to (7) in a cross section perpendicular to the longitudinal direction of the bumper beam according to, the whole of the first top plate portion second than a straight line connecting between bisector point of the first vertical wall portion preferably positioned on the opposite side of the member.
[0025]
　(9) vehicle bumper beam according to (1) to (8) is disposed, comprises a bumper beam according to (1) to (8) to the front or rear of the vehicle. In this case, the second member of the bumper beam is arranged to be on the outside of the vehicle.
[0026]
　Hereinafter, with reference to the drawings, an embodiment of the present invention in detail. Its description will not be repeated the same reference numerals designate like or corresponding parts in FIG. Further, as an example in the following, the case of applying the bumper beam of this embodiment in a vehicle front bumper.
[0027]
　Figure 1 is a cross-sectional view of a bumper beam of the present embodiment. In Figure 1, it shows a cross section perpendicular to the longitudinal direction of the bumper beam. Referring to FIG. 1, the bumper beam 1 is arranged inside the bumper 10 of the vehicle. Bumper beam 1 is provided with a first member 2 and the second member 3. Bumper beam 1 has a cross-sectional shape shown in FIG. 1, extending in the vehicle width direction.
[0028]
　First member]
　The first member 2 comprises a first top plate portion 5, two first vertical wall portion 6a, 6b and two of the first flange portion 7a, a 7b. The first top plate portion 5, in a cross section perpendicular to the longitudinal direction of the bumper beam 1, is flat. Here, the flat, first top plate portion 5 is strictly flat, does not mean only that there is no any irregularities and curved. In the present specification, the flat, in a cross section perpendicular to the longitudinal direction of the bumper beam 1, and the bisector point of the vehicle length direction of the whole of the first top plate portion 5 is one of the first vertical wall portion 6a, the other comprising opposite (vehicle length direction of the back) and the second member 3 from the straight line connecting the bisector point of the vehicle length direction of the first vertical wall portion 6b of the.
[0029]
　When the load acting from the second member 3 in the first member 2 bumper beam 1 is deformed, tensile force is generated in the longitudinal direction of the first top plate portion 5. Tensile force generated in the first top panel section 5 depends on the tensile stress generated in the cross-sectional area and the first top plate portion 5 of the first top plate portion 5. Details are described in Example 7, but the cross-sectional area of ​​the first top plate portion 5 of the bumper beam in Patent Document 4 is small (see FIG. 15). Therefore, tensile force generated in the first top plate portion 5 of the Patent Document 4 is small. Further, if the plate thickness is the same, the mass of the bumper beam of Patent Document 4, minute convex portion of the first top panel section 5 40 (see FIG. 15), heavy. Thus, in the configuration of the bumper beam in Patent Document 4, it is difficult to further increase the maximum allowable load per unit mass. On the other hand, since the first top plate portion 5 of the bumper beam 1 of the present embodiment is flat, it is possible to increase the maximum allowable load per unit mass.
[0030]
　Two first vertical wall portion 6a, 6b of the respective end leads to each of the side portions 5a, 5b of the first top plate portion 5. The first vertical wall portion 6a, the other end of 6b leads to each of the first flange portion 7a, 7b. The cross-sectional shape of the first member 2 is open cross-section of the hat-shaped. That is, the two flange portions 7a, 7b between each other, are open. The first member 2 is, for example, is obtained by press-molding a metal plate. Not limited thereto, the first member 2 may be other materials. For example, the material may be other than metal, such as CFRP.
[0031]
　Second member]
　The second member 3 includes a second top plate 4, two second vertical wall portion 8a, 8b and two second flange portions 9a, the 9b. The second top plate 4 has a convex portion 20 that protrudes toward the side opposite to the first top plate portion 5. Two second vertical wall portion 8a, 8b is, both side portions 4a of the second top plate 4, leading to respective 4b. Arrangement in the case of constituting the bumper beam 1 in the first member 2 and the second member 3 is as follows. The second vertical wall portion 8a, 8b has a first vertical wall portion 6a, 6b are arranged opposite to each. The second vertical wall portion 8a, 8b has a first vertical wall portion 6a, close to 6b. The second vertical wall portion 8a, 8b and the first vertical wall portion 6a, there may be a slight gap d between the 6b. The second vertical wall portion 8a, 8b is arranged inside the first member 2. That is, the second vertical wall portion 8a, 8b has a first vertical wall portion 6a, are disposed between 6b together.
[0032]
　Two second flange portions 9a, 9b, the second vertical wall portion 8a, 8b leads to respectively. Joint 51 is provided between the second member 3 and the first member 2. More specifically, the second flange portion 9a, 9b, respectively, the first flange portion 7a, is joined to 7b. The second member 3 has a first flange portion 7a, connecting 7b together. That is, the first member 2 and the second member 3 joined to each other to form a closed section. The second member 3 is, for example, is obtained by press-molding a metal plate. Not limited thereto, the second member 3 may be other materials. For example, the material may be other than metal, such as CFRP.
[0033]
　Such bumper beam 1 is arranged so that the second member 3 on the outside of the vehicle. And the second member 3 of the bumper beam 1 is arranged to be on the outside of the vehicle, it means the direction of arrangement of the second member 3. The second member 3 of the bumper beam 1 does not mean that they are exposed to the outside of the vehicle. For example, if the bumper beam 1 is applied as the front bumper of the bumper beam of the vehicle, the second member 3 is arranged so that the front side of the vehicle. In this case, the first member 2 is disposed so that the rear side of the vehicle. In a state where the bumper beam 1 is mounted on the vehicle, perpendicular to the second top plate 4 of the first top plate portion 5 and the second member 3 of the first member 2 is generally along the longitudinal direction of the vehicle. The first vertical wall portion 6a of the first member 2, the perpendicular of 6b is generally along the vehicle height direction. Thus, the bumper beam 1 has a higher energy absorption efficiency with respect to the vehicle length direction of the collision. Here, the energy absorption efficiency is a value bumper beam has an energy absorbing divided by the mass of the bumper beam when the collision load loaded. That is, the energy absorption efficiency is high bumper beam it is lightweight and has high strength. It will be described in detail below this point.
[0034]
　Effects of the position of the second member]
　Figures 2 and 3 are sectional views of a typical bumper beam without a reinforcing member. As shown in FIG. 2, the second member 102 of the bumper beam 100 is merely plate member. That is, the second member 102, as in the second member 3 of the embodiment shown in FIG. 1, the second vertical wall portions 8a, 8b (hereinafter, also referred to as a second vertical wall portion 8 collectively.) And the no 2 top plate 4.
[0035]
　Arrangement of the vehicle of the bumper beam is two ways. First, as shown in FIG. 2, when arranged to be the second member 102 to the outside of the vehicle (hereinafter, the case 1 and referred.). Second, as shown in FIG. 3, when arranged to be the first member 101 to the outside of the vehicle (hereinafter, the case 2 and referred.). The present inventors have found that in order to understand the fundamental properties of the bumper beam, relates cases 1 and 2, were examined energy absorption efficiency by simulation bending dynamic three-point.
[0036]
　And a load P in the direction toward the top plate 105 over the longitudinal center of the vehicle height direction of the entire area of ​​the case 1 in the second member 102. The center longitudinal of the case 2, the top plate 105 over the entire area of ​​the vehicle height direction and the load P in the direction toward the second member 102 to the load. Then, to investigate the deformation behavior of the bumper beam. At that time, for each bumper beam to examine the relationship between the amount of deflection the load P. Here, the deflection amount refers to the amount of deflection of the portion a load P. In the simulation bending dynamic three-point, the load application rate and 9km / h, and the support span and 800 mm. The results are shown in FIGS. 4-7.
[0037]
　4 to 6 are diagrams showing the deformation behavior of the bumper beam of the case 1. Deformation of the bumper beam proceeds in the order shown in FIGS. 4, 5 and 6. Referring to FIGS. 4 to 6, when the load P to the second member 102 is loaded, the compression force along the longitudinal direction of the bumper beam to the end portion X near the vertical wall portion 106 (vehicle width direction) acts to. Here, compressive force refers to force tending shrink each two vertical wall portions 106 in the longitudinal direction of the bumper beam. By the action of the compressive force, the end portion X of the second member 102 side of the vertical wall portion 106 is moved toward the center of the vehicle height direction. As a result, the vertical wall portion 106 is deformed, buckling the end. When the vertical wall portion 106 is buckled in the cross section perpendicular to the longitudinal direction, the height of the bumper beam is greatly reduced.
[0038]
　Figure 7 is a load related to a bumper beam of the cases 1 and 2 - is a deflection diagram. The vertical axis represents the load, and the abscissa indicates the amount of deflection. In Figure 7, the solid line shows the results of the bumper beam of the case 1, the broken line shows the results of a bumper beam of the case 2. Load 7 - that the deflection diagram the following is shown. In case 1, when the amount of deflection is about 38mm, the maximum permissible load. Maximum allowable load is about 62KN. When the amount of deflection is greater than about 38mm, the vertical wall portion 106 is buckled. In Case 2, when the amount of deflection is about 42mm, the maximum permissible load. Maximum allowable load is about 50 kN. When the amount of deflection is greater than about 42mm, the vertical wall portion 106 is buckled. From this, the maximum allowable load of the case 1 is found to be higher than the maximum permissible load of the case 2.
[0039]
　Vertical wall for a bumper beam of the case 1, as shown in FIGS. 4 to 6, in which the compressive force acting on the vertical wall portion 106, the end portion X moves toward the center of the vehicle height direction of the bumper beam at an early stage part 106 succumb seat deforms. In other words, if suppress the movement of the end portion X, it is possible to suppress the vertical wall portion 106 is buckled at an early stage. Therefore, as shown in FIG. 1, between the first vertical wall portion 6 between the bumper beam 1 in the first member 2 of the present embodiment (inside of the first member 2), the second vertical wall of the second member 3 parts 8 and the second top plate 4 is arranged.
[0040]
　Advantages of the second vertical wall portion]
　Referring to Figure 1, when a collision load acts on the bumper beam bumper beam is bending deformation. At this time, the end portion X of the first vertical wall portion 6 as described above, moves toward the bumper beam center of the vehicle height direction. The bumper beam of this embodiment, the inner side of the first vertical wall portion 6 exists the second vertical wall portion 8 of the second member 3. Therefore, when the end portion X of the first vertical wall portion 6 moves, the end portion X is in contact with the second vertical wall portion 8. Accordingly, inward deformation of the end portion X of the first vertical wall portion 6 is suppressed. As a result, buckling of the first vertical wall portion 6 is suppressed, the maximum allowable load of the bumper beam is increased.
[0041]
　Based on Example 2 described later, the height h1 of the second vertical wall portion 8 ratio h1 / H between the height H of the first vertical wall portion 6, 0.1 or higher, that is 0.5 or less preferable. Here, the height H of the first vertical wall portion 6 refers to the first top plate portion 5 the distance between the first flange portion 7. The height h1 of the second vertical wall portion 8, a second top plate 4 a second flange portion 9a, means the distance between the 9b.
[0042]
　If the ratio h1 / H is small, when the collision load is added, the area of ​​the second vertical wall portion 8 which ends X and its surroundings of the first vertical wall portion 6 are in contact is small. Therefore, it is difficult to suppress deformation of the first vertical wall portion 6. Therefore, the maximum allowable load of the bumper beam is less likely sufficiently high. Accordingly, the lower limit of the ratio h1 / H is preferably 0.1. More preferably, the lower limit of the ratio h1 / H is 0.2.
[0043]
　End X of the first vertical wall portion 6 is preferably in contact with the region near the second top plate 4 of the second vertical wall portion 8. This is because the movement of the bumper beam center of the end portion X of the first vertical wall portion 6 (inner) is suppressed by the reaction force of the second top plate 4. If the ratio h1 / H is large, the distance between the second top plate 4 and the end portion X of the first vertical wall portion 6 is far. It is the end X of the first vertical wall portion 6 comes into contact with the second vertical wall portion 8, the reaction force which the end X of the first vertical wall portion 6 receives from the second top plate 4 is small. Therefore, it is difficult to suppress the deformation of the first vertical wall portion 6, the maximum allowable load of the bumper beam is less likely sufficiently high. Therefore, the upper limit of the ratio h1 / H is preferably 0.5. More preferably, the upper limit of the ratio h1 / H is 0.4.
[0044]
　The second vertical wall portion 8 are opposed in proximity to the first vertical wall portion 6. A first vertical wall portion 6 there may be a gap d between the second vertical wall portion 8. Based on Example 3 to be described later, the gap d is, 0 mm or more, preferably 10mm or less. Gap d is 0, that is, most the maximum permissible load of the bumper beam is high clearance absence. On the other hand, if manufacturing the first member 2 and the second member 3 by eliminating the clearance, dimensional accuracy required for each member becomes severe. Some of the gap d in consideration of the productivity is acceptable. Conversely, if the clearance d is too large, the end portion X of the first vertical wall portion 6 comes into contact with the second vertical wall portion 8 after the first vertical wall portion 6 buckles. That is, the first vertical wall portion 6 because it is too far away and the second vertical wall portion 8, the inward movement of the end portion X of the first vertical wall portion 6 is not inhibited by the second vertical wall portion 8. That is, the maximum allowable load of the bumper beam is less likely higher. Therefore, the upper limit of the gap d is preferably between 10 mm. More preferably, the upper limit of the gap d is 9 mm.
[0045]
　The second flange portion 9a, 9b is first vertical wall portion 6a, the first flange portion 7a in 6b and close, is preferably joined to 7b. The second top plate 4, bending longitudinally subjected to compressive force during deformation, out-of-plane deformation in the longitudinal direction of the vehicle. As a result, when the second top plate 4 is out-of-plane deformation in the longitudinal direction of the vehicle forward, the first vertical wall portion 6a, 6b and the second vertical wall portion 8a, 8b are less likely to contact, the first vertical wall portion 6a , it is difficult to obtain the effect of suppressing 6b is deformed inwardly. Plane deformation in the vehicle length direction in front of the second top plate 4, depending on the distance between the joints 51 in the vehicle height direction, the distance between the joint portion 51 is liable to out-of-plane deformation longer. Therefore, in order to maximize the effect of suppressing the first vertical wall portion 6a, 6b is deformed bumper beam center side (inner side), the second flange portion 9a, 9b (hereinafter, the collectively 2 also referred to as a flange portion 9.), the first vertical wall portion 6a, the first flange portion 7a in 6b and close, is preferably joined to 7b. Junction 51, first flange portion 7a, the first vertical wall portion 6a of 7b, be provided from an end portion of 6b side in the region within 15mm desirable.
[0046]
　[Effect of the projections]
　As shown in FIG. 1, the second top plate 3 of the convex portion 20 has a flat portion 21 and the wall portion 22a, a 22b. In Figure 1, the wall portion 22a, 22b shows a case which is parallel to the second vertical wall portion 8. However, the walls 22a, 22b may not be parallel to the second vertical wall portion 8. Protrusion 20 is directed to protrude on the opposite side of the first top plate portion 5 of the first member 2. That is, when mounting the bumper beam 1 in a vehicle, the convex portion 20 protrudes toward the outside of the vehicle.
[0047]
　Figure 8 is a diagram showing the deformation behavior of the bumper beam schematically. When a collision load to the bumper beam is loaded, the flat portion 21 of the protrusion 20 is deformed in a direction towards the rear of the vehicle length direction (refer to the outlined arrow in FIG. 8). In this case, across the center of the vehicle height direction, the vehicle upper side of the wall portion 22a are deformed in the vehicle height direction upper wall portion 22b of the vehicle lower side is deformed in the vehicle height direction downward (solid arrow see in FIG. 8 ). Thus, a region other than the convex portion 20 of the second top plate 4 (the bottom surface 23 of the second top plate 4) moves deformed toward the first vertical wall portion 6. Therefore, deformation of the bumper beam inside of the first vertical wall portion 6 is suppressed. Thus, the first vertical wall portion 6 because the buckling is suppressed, the maximum allowable load of the bumper beam is further increased.
[0048]
　Based on Example 4 to be described later, the ratio w1 / W of the width W of the width w1 between the first top plate portion 5 of the convex portion 20 shown in FIG. 1, 0.1 or more, preferably at 0.7 or less . Here, the width W of the first top panel section 5 refers to the distance between the first vertical wall portion 6. Width w1 of the convex portion 20 refers wall 22a of the projections 20, the distance between 22b. In the case wall portion 22a, 22b is not parallel to the second vertical wall portion 8, the width w1 of the convex portion 20, the wall portion 22a, the flat portion 21 on the opposite side of 22b (i.e., the opening side of the convex portion 20) It refers to the distance between the adjacent ends.
[0049]
　The ratio w1 / W is small, compared to the vehicle height direction of the width of the convex portion 20, it means that the vehicle height direction of the width of the second top plate 4 of the bottom surface 23 is large. When the ratio w1 / W is too small, the bottom surface 23 of the second top plate 4 is easily bent in the impact load direction, hardly buckling of the first vertical wall portion 6 is sufficiently suppressed. Accordingly, the lower limit of the ratio w1 / W is preferably 0.1. More preferably, the lower limit of the ratio w1 / W is 0.2.
[0050]
　If the ratio w1 / W is too large, the vehicle height direction of the width of the convex portion 20 is large, flat portions 21 of the projections 20 is easily bent in the impact load direction, sufficiently suppress the buckling of the first vertical wall portion 6 hardly. Therefore, the upper limit of the ratio w1 / W is preferably from 0.7. More preferably, the upper limit of the ratio w1 / W is 0.6.
[0051]
　Based on Example 6 to be described later, the ratio h2 / h1 between the height h1 of the second vertical wall portion 8 of the height h2 and the second member 3 of the protrusion 20 shown in FIG. 1, 0.5 or more, 1. a is preferably 1 or less. Here, the height h2 of the projecting portion 20 refers to the distance between the flat portion 21 and the second top plate 4 of the bottom surface 23 of the projections 20.
[0052]
　If the ratio h2 / h1 is small, since the height of the projections 20 is small, the wall portion 22a of the projections 20, 22b is less likely to deform. Therefore, even when loaded collision load to the bumper beam, the convex portion 20 is less likely to be deformed, it is difficult to suppress deformation of the first vertical wall portion 16. Accordingly, the lower limit of the ratio h2 / h1 is preferably 0.5. More preferably, the lower limit of the ratio h2 / h1 is 0.6.
[0053]
　If the ratio h2 / h1 is 1.0, since the projections 20 from the earliest collision begins to deform, most desirable. It also allows the ratio h2 / h1 is slightly greater than 1.0. If the ratio h2 / h1 is more than 1.0, the convex portion 20 begins to deform before the bumper beam main body collides. The ratio h2 / h1 is larger than 1.0, if there is a gap between the first vertical wall portion 6 of the second vertical wall portion 8, it can be particularly recommended. This is because, when the bumper beam main body has collided is because the second vertical wall portion 8 towards the first vertical wall portion 6 is approaching. The ratio amount of more than 1.0 of h2 / h1 may be determined depending on the size of the gap between the first vertical wall portion 6 of the second vertical wall portion 8. For example an upper limit of the ratio h2 / h1 is allowed to 1.1.
[0054]
　Meanwhile, a first flange portion 7 joining the second flange portion 9 (see FIG. 1) is, for example, a welding. Welding method, for example, spot welding, plug welding, arc welding, a laser welding or the like. However, the first flange portion 7 joining the second flange portion 9 is not limited to welding. A first flange portion 7 joining the second flange portion 9 may be a mechanical junction. Mechanical bonding, for example, rivets, bolts and nuts, a screw or the like. Further, a first flange portion 7 joining the second flange portion 9 may be an adhesive. Furthermore, the first flange portion 7 joining the second flange portion 9, the weld may be a combination of mechanical bonding and adhesive.
[0055]
　As described above, in the bumper beam of the present embodiment is arranged so that the second member 3 on the outside of the vehicle. For example, as shown in FIG. 9, the bumper beam 1 is curved in the longitudinal direction. In this case, the outer arc of the bumper beam 1 is curved (second member 3 side in FIG. 9) is arranged to project to the outside of the vehicle. Further, the bumper beam 1, the crash box that is located inside the vehicle, is attached to the front side member 30 or the like. Therefore, the vehicle inner side surface of the bumper beam 1 (e.g., a first top panel section 5), mounting holes, etc. are provided. In short, even bumper beam 1 is not attached to the vehicle, both parts of the first member 2 and second member 3 of the bumper beam 1 can be determined either arranged to be outside of the vehicle.
[0056]
　In the above embodiment has been described the case in which the bumper beam is made of a metal plate. The metal plate, for example, steel, aluminum plate, titanium plate, magnesium plate, copper plate, nickel plate or an alloy plate, a multilayer metal plate. Since the present invention relates to the shape of the bumper beam, the non-metal CFRP may be used as the material satisfies even necessary strength to the bumper beam.
[0057]
　When applying the bumper beam of the present embodiment in a vehicle, the first member and the second member, preferably the tensile strength is from the above steel sheet 1GPa is. In this case, the strength without increasing the weight of the bumper beam can more be increased that a further improved vehicle safety, and, thereby the weight of the vehicle body.
[0058]
　In the above embodiment, the vehicle has been described the case of providing a bumper beam to the front. That it has been described a case of applying the bumper beam of this embodiment as a bumper beam of a vehicle front bumper. However, the bumper beam of this embodiment is not limited to the bumper beam of a front bumper. Bumper beam of this embodiment may be located at the rear of the vehicle. That is, the bumper beam of this embodiment can also be applied to the rear bumper. In any case, the second member of the bumper beam is arranged to be on the outside of the vehicle.
Example 1
[0059]
　Performs a load load simulation for a bumper beam shape of the second member are different, investigated the maximum permissible load and energy absorption efficiency.
[0060]
　10 to 12 show bumper beam model used in the study of Example 1. Figure 10 shows a bumper beam of the present invention Example 1. Figure 11 shows a bumper beam of the reference example. Figure 12 shows a bumper beam of Comparative Example 1. For the dimensions of these bumper beam, the height H of the vertical wall portion of the first member is 60 mm, the width W of the first top panel section 80 mm, the width W2 of the second member was 120 mm. In the present invention Example 1 and Reference Example, the first vertical wall portion gap d between the second vertical wall portion 0 mm, the height h1 of the second vertical wall portion was 15 mm. In the present invention Example 1, the height h2 of the projecting portion is 15 mm, the width w1 of the convex portion was set to 30 mm. Invention Example 1, Reference Example and Comparative Example 1, the load P is loaded toward the first member in the middle of the second member. First and second members, the tensile strength is 1310MPa, plate thickness assuming a steel 1.4 mm. The joining models the spot welding, the first flange portion 7a, the first vertical wall portion 6a of 7b, provided from an end portion of 6b side to 10mm area. 4.7mm spot welding diameter, the distance between the center of the spot welding was 30mm pitch.
[0061]
　13, the load for each bumper beam of Example 1 - a deflection curve. In Figure 13, the solid line shows the results of the present invention Example 1, the broken line represents a reference example, a one-dot chain line indicates a comparative example 1. As shown in FIG. 13, the maximum allowable load of the present invention Example 1 was 59.2KN. The maximum permissible load of the reference example was 51.5kN. Maximum allowable load in Comparative Example 1 was 34.1KN.
[0062]
　Based on the simulation result of Example 1, the maximum permissible load and deflection per unit mass of each bumper beam is calculated energy absorption efficiency of the bumper beam up to 60 mm. The results are shown in Table 1. Incidentally, the energy absorption efficiency, the amount of deflection was calculated based on the energy of up to 60 mm.
[0063]
[Table 1]

[0064]
　As shown in Table 1, the maximum permissible load of the present invention Example 1 was higher than the maximum allowable load of Comparative Example 1. Furthermore, the energy absorption efficiency of the present invention Example 1 was higher than the energy absorption efficiency of Comparative Example 1.
Example 2
[0065]
　In Example 2, using the model of the present invention embodiment shown in the same FIG. 10 as in Example 1, the height h1 of the second vertical wall portion variously changes, were examined maximum permissible load. The simulation was performed for three patterns of the ratio h1 / H = 0.17,0.25,0.50 between the height h1 of the second vertical wall portion and the height H of the first member. The results are shown in Table 2.
[0066]
[Table 2]

[0067]
　As shown in Table 2, none of the maximum allowable load of the bumper beam used in Example 2, was higher than the maximum allowable load 34.1kN of the bumper beam of Comparative Example 1 shown in Table 1. Moreover, none of the maximum allowable load per unit mass of the bumper beam used in Example 2, was higher than the maximum allowable load 9.0kN / kg per unit weight of the bumper beam of Comparative Example 1 shown in Table 1.
Example 3
[0068]
　In Example 3, using the model of the present invention embodiment shown in the same FIG. 10 as in Example 1, and the first vertical wall portion a gap d between the second vertical wall portion variously changes, were examined maximum permissible load. Gap d was conducted on two patterns of d = 0,5,10mm. The results are shown in Table 3.
[0069]
[table 3]

[0070]
　As shown in Table 3, none of the maximum allowable load of the bumper beam used in Example 3 was higher than the maximum allowable load 34.1kN of the bumper beam of Comparative Example 1 shown in Table 1.
Example 4
[0071]
　In Example 4, using the model of the present invention embodiment shown in the same FIG. 10 as in Example 1, the width w1 of the convex portion of the second member variously modified, examined the maximum allowable load. The simulation was performed for three patterns of the ratio w1 / W = 0.59,0.41,0.19 the width w1 of the convex part to the width W of the first top plate portion. The results are shown in Table 4.
[0072]
[Table 4]

[0073]
　As shown in Table 4, both the maximum allowable load of the bumper beam as used in Example 4 was higher than the maximum allowable load 34.1kN of the bumper beam of Comparative Example 1 shown in Table 1. Moreover, none of the maximum allowable load per unit mass of the bumper beam as used in Example 4 was higher than the maximum allowable load 9.0kN / kg per unit weight of the bumper beam of Comparative Example 1 shown in Table 1.
Example 5
[0074]
　In Example 5, using the model of the present invention embodiment shown in the same FIG. 10 as in Example 1, the angle θ of the protrusion of the second member variously modified, examined the maximum allowable load. Here, the angle θ of the projecting portion, the wall portion 22a of the flat portion 21 and the convex portion of the convex portion, of the angle between 22b, refers to an angle towards acute (see Figure 14). Angle theta was conducted on three patterns of θ = 90,60,45 °. The results are shown in Table 5.
[0075]
[table 5]

[0076]
　As shown in Table 5, none of the maximum allowable load of the bumper beam used in Example 5 was higher than the maximum allowable load 34.1kN of the bumper beam of Comparative Example 1 shown in Table 1.
Example 6
[0077]
　In Example 6, using the model of the present invention embodiment shown in the same FIG. 10 as in Example 1, the height h2 of the projecting portion of the second member variously modified, examined the maximum allowable load. The simulation was performed on two patterns of the ratio h2 / h1 = 0.67,1.0 between the height h2 of the convex portion and the height h1 of the second vertical wall portion. The results are shown in Table 6.
[0078]
[Table 6]

[0079]
　As shown in Table 6, none of the maximum allowable load of the bumper beam used in Example 6 was higher than the maximum allowable load 34.1kN of the bumper beam of Comparative Example 1 shown in Table 1. Moreover, none of the maximum allowable load per unit mass of the bumper beam used in Example 6 was higher than the maximum allowable load 9.0kN / kg per unit weight of the bumper beam of Comparative Example 1 shown in Table 1. Incidentally, when the gap d between the first vertical wall portion and the second vertical wall portion is larger than 0, also allows the ratio h2 / h1 is slightly greater than 1.0. From the results of Examples 3, the gap d is advantageously closer to 0. If the gap d is larger than 0, the ratio h2 / h1 is more than 1.0, advantageously since the second vertical wall portion 8 towards the first vertical wall portion 6 is close when the bumper beam main body has collided it is. For example an upper limit of the ratio h2 / h1 is allowed to 1.1.
Example 7
[0080]
　In Example 7, the maximum allowable model and the model and the maximum permissible load and per unit mass of the comparative example having the same shape and the bumper beam shown in Patent Document 4 of the present invention embodiment shown in the same FIG. 10 as in Example 1 to compare the load. In Example 7, a simulation was performed for the two patterns of height H = 40,60mm first vertical wall portion.
[0081]
　Figure 15 is a diagram showing a bumper beam of Comparative Examples 2-5. As shown in FIG. 15, the first top plate portion 5 of the bumper beam of Comparative Examples 2 to 5, including a convex portion 40 that protrudes toward the second member 3 side. The bumper beam of Comparative Examples 2 and 3, the convex portion 40 of the first top plate portion 5, joined to the protruding portion 20 of the second top plate 4. The bumper beam of Comparative Examples 4 and 5, the convex portion 40 of the first top plate portion 5 was not joined with the convex portion 20 of the second top plate 4. In Example 7, the tensile strength of all the models of the present invention and comparative example example was assumed to 980 MPa. Inventive Example 2, Comparative Example 2 and Comparative Example 4, by changing the thickness of each model, the mass of the bumper beam and Equalize. Invention Example 3, in Comparative Example 3 and Comparative Example 5 were the same. The results of Example 7 are shown in Table 7.
[0082]
[Table 7]

[0083]
　As shown in Table 7, the maximum allowable load per unit mass of the bumper beam of the present invention example 2, the maximum allowable load per unit mass of Comparative Example 2 and 4 of the bumper beam of the same height H as Working Example 2 It was higher than that. Similarly, the maximum allowable load per unit mass of the bumper beam of the present invention Example 3 was higher than the maximum allowable load per unit mass of the bumper beam of Comparative Examples 3 and 5 of the same height H as Working Example 3 . This is estimated to be due to the following reasons.
[0084]
　Referring to FIG. 15, when the bumper beam is deformed, the first top plate portion 5 is stretched in the longitudinal direction. That is, the tensile force is generated in the longitudinal direction of the first top plate portion 5. Tensile stress occurs throughout the first top plate portion 5 depends on the distance from the neutral surface N of the bending of the bumper beam. This is because the deformation from the neutral plane N of the bending of the bumper beam farther to the first top plate portion 5 becomes large, the tensile stress is increased. Neutral surface N of the bending of the bumper beam will substantially same position as the plane defined by the straight line connecting the bisector point between the first vertical wall portion 6. Not perfectly coincide, the thickness of the plate material constituting the bumper beam by conditions such as heterogeneous, because the position of the neutral surface N is sometimes shift slightly.
[0085]
　The first top plate portion 5 of the bumper beam of Patent Document 4 has a convex portion 40 toward the inside of the bumper beam. Sectional area of ​​the protrusion 40 as the convex portion 40 becomes larger increases. That is, the mass of the bumper beam is increased. On the other hand, as the position closer to the neutral plane N of the convex portion 40, the tensile stress generated in the position is reduced. Tensile force generated in the member can be obtained by integrating the tensile stress in the cross-sectional area. The greatest tensile stress is generated when the collision load is applied to the bumper beam is first top plate portion 5. Bumper beam of Patent Document 4 is narrow amount corresponding first top plate portion 5 of the protrusion 40. That is, the bumper beam of Patent Document 4, the region where the greatest tensile force arises out of the bumper beam is narrow. Further, the bumper beam of Patent Document 4, there is a lower portion of occurring tensile stresses when the bumper beam is deformed (protrusion 40). Therefore compared with the present embodiment, the maximum allowable load per unit mass of the bumper beam in Patent Document 4 is low. On the other hand, of the convex portion 40, portion beyond the neutral surface N of the bending of the bumper beam is compressed and deformed in the opposite. In this case, among the convex portions 40, the flat end 41 for out-of-plane deformation, compressive stress is generated only in the ridge portion 42 of the protrusion 40. In other words, the region where the compressive stress is generated is small, the compression force generated in the convex portion 40 is small. As a result, among the convex portions 40, portions beyond the neutral surface N of the bending of the bumper beam is difficult to contribute to an increase in the maximum allowable load.
[0086]
　Thus, in the bumper beam of this embodiment, in the first top plate portion 5 as there is a protrusion toward the inside of the bumper beam, the convex portion does not exceed the neutral surface N of the bending of the bumper beam. A neutral plane N of the bending of the bumper beam includes a bisector point of the vehicle length direction of the approximate one of the first vertical wall portion 6a, a bisector point of the vehicle length direction of the other of the first vertical wall portion 6b It is formed by a straight line drawn from (see Figure 1). More preferably, even if the convex portion toward the inside of the bumper beam, and a point closest to the first top plate portion 5 of the five equally divided points of the vehicle length direction of the first vertical wall portion 6a, the other of the first linear and convex portions of the first top plate portion 5 connecting the point closest to the first top plate portion 5 of the five equally divided points of the vehicle length direction of one vertical wall portion 6b is not in contact.
[0087]
　In short, the bumper beam of the comparative example mass is large, by ones of that area of ​​the portion where the tensile force is generated is large and the bumper beam weight of the first top plate portion is small, per unit mass of the bumper beam of the present invention embodiment the maximum permissible load, is greater than the maximum allowable load per unit mass of the bumper beam of the comparative example.
[0088]
　It has been described an embodiment of the present invention. However, 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 changing the above-described embodiments without departing from the scope and spirit thereof as appropriate.
DESCRIPTION OF SYMBOLS
[0089]
　　1 bumper beam
　　2 first member
　　3 second member
　　4 and the second top plate portion
　　5 first top plate portion
　　6 first vertical wall portion
　　7 first flange portion
　　8 second vertical wall portion
　　second flange portion 9
　10 bumper
　20 protrusion
　flat portion 21 protrusion
　22a, the wall portion of 22b protruding portion
　　d first vertical wall portion and the gap between the second vertical wall portion
　　height H first vertical wall portion
　height h1 second vertical wall portion
　h2 protrusion height
　　W the width of the first top plate portion
　width w1 protrusions
　　P collision load
　　end of the X first vertical wall portion

WE claims

[Requested item 1]
　In the cross section perpendicular to the longitudinal direction, the first top plate portion flat, the two first vertical wall portion leading to each of the side portions of the first top plate portion, and connected to each of the two first vertical wall portion of 2 One of the first member including a first flange portion,
　the second top plate portion having a convex portion protruding toward the side opposite to the first top plate portion, the first lead on each of both sides of the second top plate portion the second vertical wall portions of the two facing each closely inside said first member to a vertical wall, respectively, and bonded to each of the two second vertical wall portion connected to each of the first flange portion the vehicle bumper beam comprising a second member, the comprising two second flange portion disposed.
[Requested item 2]
　The vehicle bumper beam defined in claim 1,
　the ratio h1 / H between the height H of the height h1 of the second vertical wall portion of the first vertical wall portion, 0.1 or more, 0. 5 or less, the bumper beam for a vehicle.
[Requested item 3]
　The vehicle bumper beam according to claim 1 or claim 2,
　wherein the gap between the first vertical wall portion and the second vertical wall portion, 0 mm or more and 10mm or less, the bumper beam for a vehicle.
[Requested item 4]
　The vehicle bumper beam according to any one of claims 1 to 3,
　the ratio of the width W of the width w1 and the first top plate portion of the convex portion of the second top plate portion w1 / W is 0.1 or more and 0.7 or less,
　the ratio between the height h1 of the second vertical wall portion of the second member and the height h2 of the convex portion of the second top plate portion h2 / h1 is 0.5 or more and 1.1 or less, the bumper beam for a vehicle.
[Requested item 5]
　The vehicle bumper beam according to any one of claims 1 to 4,
　and the first flange portion and the second flange portion is welded, bonded, are joined rivets, or by combinations of these It is, bumper beam for a vehicle.
[Requested item 6]
　The vehicle bumper beam according to any one of claims 1 to 5,
　wherein the first member and the second member is made of steel sheet, the tensile strength of the steel sheet is not less than 1 GPa, vehicle bumper beam.
[Requested item 7]
　The vehicle bumper beam according to any one of claims 1 to 6,
　wherein the joint portion of the second flange portion and the first flange portion, 15 mm from the edge of the first vertical wall portion provided within the region, the bumper beam for a vehicle.
[Requested item 8]
　The vehicle bumper beam according to any one of claims 1 to 7,
　wherein in the cross section perpendicular to the longitudinal direction, all of the first top plate portion 2 and the like of the first vertical wall portion It situated the straight line connecting the equinox each other on the opposite side of the second member, a bumper beam for a vehicle.
[Requested item 9]
　Comprising a vehicle bumper beam according to front or rear to any one of claims 1 to 8,
　wherein the second member of the bumper beam is arranged to be outside the vehicle, the vehicle.