Shock absorption structure for vehicle body

Abstract

This shock absorption structure for a vehicle body includes an energy absorption member (20) having a hat-like cross-sectional shape in a collision load input-direction. A top plate section (20A) in the hat-like shape is disposed facing the input direction. Coupling sections (20D), (20E) for respectively coupling flange sections (20C) and the top plate section (20A) to a pair of vertical wall parts (20B) are formed into a bent shape. Dimensions in directions in which the flange parts (20C) extend in the bent shape include a first dimension L1 in the bent shape towards each flange part (20C) that is greater than or equal to a prescribed value, and that is greater than or equal to a second dimension L2 in the bent shape towards the top plate part (20A).

Description

Impact absorbing structure of the vehicle body

[0001] The present invention relates to an impact absorbing structure for a vehicle body.

[0002] For example, as disclosed in Japanese Patent No. 7099552 (Patent Publication No. 552), a structure is known in which an energy absorbing member B is disposed inside a rocker (commonly referred to as a side sill) A with a closed cross-section structure to absorb impact during a side collision (see FIG. 20 of the present disclosure). During a side collision, the energy absorbing member B receives a collision load in the direction of the arrow and gradually deforms as shown in FIGS. 21 and 22 to absorb the collision energy and protect the occupants. The battery (not shown) and other components located inside the rocker A in the vehicle width direction are also protected.

[0003] The energy absorbing member B disclosed in the '552 publication is configured to have a pair of vertical walls C extending generally along the direction of the collision load, with grooves D recessed in opposing directions formed in each of the vertical walls C. When subjected to a collision load, the vertical walls C deform in opposing directions, triggered by the grooves D, and the vertical walls C come into contact with each other, thereby increasing the amount of energy absorbed compared to when the energy absorbing member B is not provided.

[0004] In the structural member disclosed in JP 552-16552, the pair of vertical walls C are made to be easily deformed by the grooves D at the initial stage of a collision. Therefore, there is a problem that the load received by the energy absorbing member B at the initial stage of a collision is reduced.

[0005] An object of the present disclosure is to provide an impact absorption structure for a vehicle body including an energy absorbing member having a pair of vertical walls extending in the input direction of a collision load, which generates a moment in a direction that moves the pair of vertical walls toward each other when subjected to a collision load. This moment causes the pair of vertical walls to deform so as to abut against each other when subjected to the collision load, without forming a bent shape in the pair of vertical walls that would trigger deformation such as a groove, thereby suppressing a decrease in the load received by the energy absorbing member at the initial stage of a collision.

[0006] One embodiment of the present disclosure is an impact absorbing structure for a vehicle body, comprising an energy absorbing member having a hat-shaped cross section along an input direction of a collision load, the energy absorbing member comprising a top plate portion, a pair of vertical wall portions, and a pair of flange portions, the top plate portion being arranged with its plate surfaces facing the input direction, the pair of flange portions being fixed to a single fixing member that receives the collision load, each of the flange portions and each of the joint portions of the top plate portion with respect to the pair of vertical wall portions having a curved shape, a first dimension which is the dimension in the direction in which each flange extends in the bent shape of each joint portion of the top plate portion being equal to or greater than a second dimension which is the dimension in the direction in which the top plate portion extends in the bent shape of each joint portion of the top plate portion, and the first dimension is equal to or greater than a predetermined value.

[0007] In another aspect of the present disclosure, the pair of vertical wall portions are arranged parallel to each other.

[0008] In another embodiment of the present disclosure, the ratio of a fourth dimension, which is the distance between the top plate portion and the fixing member, to a third dimension, which is the distance between the pair of vertical wall portions, is 1:7 to 1:2.5.

[0009] In another aspect of the present disclosure, the energy absorbing member is configured by two members joined at the top plate portion of the hat shape.

[0010] In another aspect of the present disclosure, the pair of vertical wall portions further include a plurality of beads formed by concave or convex stripes extending in the direction in which the top plate portion and each flange portion face each other, along the direction in which the energy absorption member extends.

[0011] 5 is a schematic configuration diagram showing an embodiment of the present disclosure. FIG. 6 is a vertical cross-sectional view of a rocker according to an embodiment of the present disclosure. FIG. 7 is an enlarged view of part III of FIG. 2. FIG. 8 is an enlarged view of part III of FIG. 2, showing a modified example of FIG. 3. FIG. 9 is a perspective view of an energy absorbing member according to an embodiment of the present disclosure. FIG. 10 is a plan view of the energy absorbing member of FIG. 11. FIG. 12 is an explanatory diagram of a moment generated on the flange side when the energy absorbing member of FIG. 11 is subjected to a collision load. FIG. 13 is an explanatory diagram of a force generated on the top plate side when the energy absorbing member of FIG. 11 is subjected to a collision load. FIG. 14 is an explanatory diagram of a schematic view of deformation at the beginning of a collision when the energy absorbing member of FIG. 11 is subjected to a collision load. FIG. 15 is an explanatory diagram of a deformation at the end of a collision when the energy absorbing member of FIG. 11 is subjected to a collision load. FIG. 16 is a characteristic diagram showing the deformation characteristics of the energy absorbing member of FIG. 11 in terms of load-displacement characteristics when the energy absorbing member of FIG. 11 is subjected to a collision load. FIG. 17 is a CAE image showing a simulation result of deformation at the beginning of a collision when the energy absorbing member of FIG. 11 is subjected to a collision load, showing the state of deformation when the first dimension of the bending shape of each joint of the flange and the top plate with respect to the vertical wall portion and the top plate is 5 mm and the second dimension is 5 mm. 12 , showing deformation when the first dimension is 10 mm and the second dimension is 10 mm. FIG. 12 , showing deformation when the first dimension is 15 mm and the second dimension is 5 mm. FIG. 12 , showing deformation when the first dimension is 15 mm and the second dimension is 10 mm. FIG. 12 , showing deformation when the first dimension is 4 mm and the second dimension is 4 mm. FIG. 12 , showing deformation when the first dimension is 5 mm and the second dimension is 10 mm. FIG. 12 , showing deformation when the first dimension is 5 mm and the second dimension is 10 mm. FIG. 12 , showing vertical cross-sectional view of a rocker illustrating another embodiment of the present disclosure. FIG. 13 , showing vertical cross-sectional view of a rocker illustrating yet another embodiment of the present disclosure. FIG. 14 , showing vertical cross-sectional view of a rocker illustrating a conventional example of the present disclosure. FIG. 20 , showing schematic deformation at the beginning of a collision when the rocker of FIG. 20 is subjected to a collision load. FIG. 21 , showing schematic deformation at the end of a collision when the rocker of FIG. 20 is subjected to a collision load.

[0012] <Overall Configuration of One Embodiment> An embodiment of an impact absorbing structure according to the present disclosure will now be described with reference to the drawings. The embodiment shown in FIG. 1 is an impact absorbing structure 1 for a battery in a side collision of an electric vehicle. However, this is just one embodiment, and the present invention is not limited to electric vehicles, and can be applied to impact absorbing structures associated with collisions with various parts of various vehicles. Note that in the directional indications in the explanations of each figure, UPR indicates the upper side, OUT indicates the outside as seen from the interior of the vehicle, FR indicates the front side of the vehicle, and RR indicates the rear side of the vehicle. Therefore, the direction indicated by UPR is the up-down direction of the vehicle body, the direction indicated by OUT is the width direction of the vehicle body, and the directions indicated by FR and RR are the fore-and-aft direction of the vehicle body.

[0013] FIG. 1 is a schematic vertical cross-sectional view of the main components of the overall configuration of an impact absorption structure 1 to which one embodiment is applied. FIG. 1 illustrates a pole side impact test in which a pole 2 is disposed. In this embodiment, an electric vehicle battery 3 is disposed under a floor 4 of the electric vehicle. A rocker 10, which forms the framework of the vehicle's lower body, is disposed on the outer side of the floor 4. Furthermore, a side door 5 (usually a front door) is disposed outside the rocker 10. In the pole side impact test, the pole 2 is also disposed outside the side door 5. In this embodiment, when the side door 5 collides with the pole 2, the energy of the collision is absorbed within a range S between the side door 5 and the battery 3, protecting the battery 3. In particular, the rocker 10 is designed to absorb energy. A cross member 6 is disposed on the floor 4, extending in the vehicle width direction. Multiple cross members 6 are provided in the fore-and-aft direction of the vehicle, reinforcing the floor 4 against side impact loads.

[0014] In this embodiment, energy absorbing members 20 are disposed throughout the entire area of ​​the rocker 10 in the vehicle's fore-and-aft direction. This allows the side impact energy to be absorbed at the location of the rocker 10. The rocker 10 includes an outer rocker member 11 disposed on the outside and an inner rocker member 12 disposed on the inside. The outer rocker member 11 and the inner rocker member 12 have a so-called hat-shaped cross section along the vehicle's width direction, which is the input direction of the collision load to the rocker 10. The outer rocker member 11 and the inner rocker member 12 have a closed cross-sectional structure in which the open sides of the outer rocker member 11 and the inner rocker member 12 are overlapped and combined with each other. As a result, the rocker 10 has a hollow structure. This hollow structure extends in the vehicle's fore-and-aft direction. The energy absorbing members 20 are made of a steel material suitable for absorbing energy through deformation due to crushing (e.g., a steel plate with a tensile strength of 590 MPa or more). Other materials, such as aluminum, may also be used.

[0015] 2 shows the detailed structure of the locker 10. The outer rocker member 11 and the inner rocker member 12 each include top plate portions 11A, 12A, vertical wall portions 11B, 12B, and flange portions 11C, 12C. The outer rocker member 11 and the inner rocker member 12 are combined with each other so that the open sides of their hat shapes face each other, and each pair of flange portions 11C, 12C are joined so that they overlap.

[0016] As shown in FIG. 5 , an energy absorbing member 20 extending in the longitudinal direction of the vehicle body is disposed within the closed cross-sectional structure formed by the outer rocker member 11 and the inner rocker member 12. Like the outer rocker member 11 and the inner rocker member 12, the energy absorbing member 20 has a hat-shaped cross section along the vehicle body width direction, which is the input direction of a collision load to the rocker 10. Therefore, the energy absorbing member 20 includes a top plate portion 20A, a pair of vertical wall portions 20B, and a pair of flange portions 20C. The pair of vertical wall portions 20B are arranged parallel to each other. While the energy absorbing member 20 may be formed by press-forming a single steel plate, in this example, the energy absorbing member 20 having a hat-shaped cross section is formed by vertically dividing the energy absorbing member 20 into two parts, an upper member 201 and a lower member 202, which are joined by welding. The welding is performed at the top plate portion 20A. Therefore, the outer ends of the upper member 201 and the lower member 202 that form the top plate portion 20A are provided with joints 201A and 202A that are joined face-to-face. By dividing the energy absorbing member 20 into two parts, upper and lower, in this way, manufacturing can be facilitated. The reason for this is that when the energy absorbing member 20 is formed by press-forming a single steel plate, it is necessary to perform press-forming using a press die that is matched to a shape in which the width dimension (fourth dimension) W of the energy absorbing member 20 is sufficiently larger than the vertical dimension (third dimension) H of the energy absorbing member 20. In contrast, when the energy absorbing member 20 is formed into two parts, upper and lower, it is possible to easily form a single energy absorbing member 20 by press-forming the upper member 201 and the lower member 202 individually and then joining them together.

[0017] The ratio of the width dimension W (the distance between the top plate portion 20A and the top plate portion 12A of the inner locker member 12) to the vertical dimension H (the distance between the vertical wall portions 20B) of the energy absorbing member 20 is approximately 1:7 to 1:2.5. The ratio of the width dimension W to the vertical dimension H of the energy absorbing member 20 may be approximately 1:5.5 to 1:3. By setting this ratio, when the energy absorbing member 20 is subjected to a collision load, the pair of vertical wall portions 20B of the energy absorbing member 20 do not deform so as to bend in the same direction, and moreover, it is possible to realize deformation in which the pair of vertical wall portions 20B deform in opposing directions, come into contact with each other, and then are crushed, as described below.

[0018] The energy absorbing member 20 is disposed with its top plate 20A facing the input direction of the collision load and abutting against the inner wall surface of the top plate 11A of the outer rocker member 11. The top plate 20A of the energy absorbing member 20 is joined to the top plate 11A of the outer rocker member 11 by one-sided access welding or with an adhesive. In addition, a pair of flanges 20C are joined to the inner wall surface of the top plate 12A of the inner rocker member 12 by welding. Therefore, the top plate 12A of the inner rocker member 12 constitutes a fixed member that receives the collision load applied to each flange 20C.

[0019] As shown in Figure 1, the joining positions of the pair of flanges 20C to the inner rocker member 12 correspond to the widthwise outer sides of the cross member 6 on the floor 4. This arrangement allows the energy absorbing member 20 to efficiently suppress the effect of a side collision impact on the floor 4. Furthermore, the energy absorbing member 20 has a pair of vertical wall portions 20B arranged parallel to one another. This has the advantage of making it easier to align the position of the energy absorbing member 20 with the area where impact absorption is desired, compared to an energy absorbing member having an inclined shape in which the spacing between the pair of vertical wall portions 20B is wider on the flange 20C side than on the top panel 20A side.

[0020] The connecting portions 20E connecting the top panel portion 20A and each vertical wall portion 20B, and the connecting portions 20D connecting each vertical wall portion 20B and each flange portion 20C, are formed in a curved shape with a rounded or inclined surface portion. FIG. 3 shows an enlarged view of an example of the curved shape of the connecting portion 20D. FIG. 4 shows an enlarged view of an example of the curved shape of the connecting portion 20D with an inclined surface portion. The rounded surface portion in FIG. 3 has a curved shape with an arcuate surface. The inclined surface portion in FIG. 4 has a curved shape with an inclined surface. Here, the inclined surface is formed such that the angle θ of the inclined surface of the connecting portion 20D with respect to the vertical wall portion 20B and the flange portion 20C is 135 degrees. While FIGS. 3 and 4 show enlarged views of the connecting portion 20D, the connecting portion 20E has a similar structure. The dimensions in the direction in which the flange portion 20C extends (vertical direction) in the bent shape of each connecting portion 20D and connecting portion 20E are such that the first dimension L1 of each connecting portion 20D is equal to or greater than a predetermined value (e.g., 5 mm) and is equal to or greater than the second dimension L2 of connecting portion 20E (see Figure 2).

[0021] As shown in FIGS. 5 and 6 , multiple beads 20F are formed on each vertical wall portion 20B of the energy absorbing member 20. FIGS. 5 and 6 show the energy absorbing member 20 joined to the inner rocker member 12 with the outer rocker member 11 removed. The beads 20F are formed as concave or convex stripes extending in the direction in which the top plate portion 20A and the flange portion 20C face each other. In FIGS. 5 and 6 , the beads 20F are formed as convex stripes in which the upper and lower surfaces of each vertical wall portion 20B bulge linearly in a mountain range shape. In this embodiment, as shown in FIG. 6 , it is desirable that four or more beads 20F are included within a range P corresponding to the diameter of the pole 2. The diameter of the pole used in the pole side impact test is 254 mm. Forming the beads 20F on the vertical wall portions 20B in this manner increases the deformation strength of the vertical wall portions 20B when the energy absorbing member 20 is subjected to a collision load directed from the top plate portion 20A toward the flange portion 20C due to a collision with the pole 2.

[0022] <Operation and Effect of One Embodiment> Figure 7 shows the transmission of force and the generation of moment when the energy absorbing member 20 receives a collision load from the direction of arrow F. When the energy absorbing member 20 receives a collision load from the direction of arrow F, the pair of vertical wall portions 20B apply force F1 toward the top plate portion 12A of the inner rocker member 12 through the flange portion 20C. As described above, the joint portion 20D is located between the vertical wall portion 20B and the flange portion 20C. Therefore, the force F1 on the vertical wall portion 20B generates a moment that lifts the tip side of the flange portion 20C (the side away from the joint portion 20D) as shown by arrow M1. This moment acts to move the top plate portion 20A sides of the vertical wall portions 20B closer to each other. That is, this force deforms the vertical wall portions 20B as shown by the two-dot chain lines in Figure 7.

[0023] 8 shows the force F2 generated on the top plate portion 20A side when the energy absorbing member 20 receives a collision load from the direction of arrow F. When the energy absorbing member 20 receives a collision load from the direction of arrow F, the force F2 is generated in the top plate portion 20A, which expands the area of ​​the top plate portion 20A in the vertical direction and expands the top plate portion 20A side of the vertical wall portion 20B in the vertical direction as shown by the two-dot chain line.

[0024] As described above, the dimension L1 of the connecting portion 20D is set equal to or greater than the dimension L2 of the connecting portion 20E, and the dimension L1 is set to a predetermined value or greater. Therefore, the effect of the moment M1 bringing the vertical wall portions 20B closer together, as shown by the two-dot chain line in FIG. 7, is greater than the effect of the force F2 moving the vertical wall portions 20B apart, as shown by the two-dot chain line in FIG. 8. As a result, the energy absorbing member 20 deforms the pair of vertical wall portions 20B near their widthwise central portions toward each other, as shown by the two-dot chain line in FIG. 7. As a result, the interaction between the moment M1 and the force F2 deforms the pair of vertical wall portions 20B of the energy absorbing member 20 toward each other in the early stage of the collision, as shown in FIG. 9. Subsequently, the deformation progresses further, causing the pair of vertical wall portions 20B to abut against each other, and in the later stage of the collision, the rocker 10 and the energy absorbing member 20 are crushed as shown in FIG. 10. As a result, the collision energy is absorbed by the rocker 10 equipped with the energy absorbing member 20.

[0025] FIG. 11 shows the load-displacement characteristics (FS characteristics) of the rocker 10 of the present invention. In FIG. 11, the solid line represents the characteristics of the rocker 10 of one embodiment of the present disclosure, and the dashed line represents the characteristics of the conventional rocker A of FIG. 20. In the rocker 10 of the present disclosure shown by the solid line, the pair of vertical wall portions 20B bend sharply toward each other at the position indicated by N1. The pair of vertical wall portions 20B abut each other at the position indicated by N2. The load drops relatively significantly at the position N2. Compared to the conventional rocker A of FIG. 20 shown by the dashed line, the rocker 10 of the present disclosure temporarily drops in load compared to the rocker A at the position indicated by N2, but the load is higher than the rocker A throughout. In the conventional rocker A, a groove D is formed that triggers deformation of the vertical wall C, as shown in FIG. 20. Therefore, the vertical wall C deforms with a small load, as indicated by N3 in FIG. 11, and the load absorbed by the energy absorbing member B is reduced overall. Therefore, it can be seen that rocker 10 has a larger energy absorption capacity than rocker A.

[0026] 12 to 17 show the results of CAE analysis performed in the above-described embodiment, with the first dimension L1 and the second dimension L2 being changed in various ways as shown in Table 1.

[0027]

[0028] The cases of Figures 12 to 15 satisfy the condition that the first dimension L1 is equal to or greater than a predetermined value (5 mm) and is equal to or greater than the second dimension L2. In the cases of Figures 12 to 15, the pair of vertical wall portions 20B of the energy absorbing member 20 subjected to a collision load can be brought into contact with each other. On the other hand, the cases of Figures 16 and 17 do not satisfy the above condition. In the cases of Figures 16 and 17, the pair of vertical wall portions 20B cannot be brought into contact with each other. From these results, it can be seen that in order to deform the pair of vertical wall portions 20B of the energy absorbing member 20 so that they come into contact with each other without providing the groove D as in the conventional example described above, the first dimension L1 must be equal to or greater than 5 mm, and L1 must satisfy the relationship L1≧L2.

[0029] 18 shows another embodiment. In this embodiment, the top plate portion 21A of the energy absorbing member 21 is spaced apart from the top plate portion 11A of the outer rocker member 11 without abutting against it. The other configurations of the other embodiment are the same as those of the first embodiment, and a repeated description of the same parts will be omitted.

[0030] In another embodiment, the energy absorbing member 21 installed within the space of the locker 10 has a smaller width than the energy absorbing member 20 in the one embodiment. The energy absorbing member 21 is fixed by welding a pair of flanges 21C to the top plate 12A of the inner locker member 12. The top plate 21A of the energy absorbing member 21 does not abut against the top plate 11A of the outer locker member 11, but is positioned slightly spaced apart.

[0031] As described above, in this other embodiment, the top plate portion 21A of the energy absorbing member 21 is spaced apart from, and does not abut against, the top plate portion 11A of the outer rocker member 11, thereby preventing defective products from being produced due to manufacturing errors. That is, a manufacturing error in which the width dimension W1 of the energy absorbing member 21 is larger than the width dimension W2 of the interior space of the locker 10 makes it difficult to join the flange portion 11C of the outer rocker member 11 and the flange portion 12C of the inner rocker member 12 can be prevented. Therefore, this other embodiment improves manufacturing yield and reduces manufacturing costs. Note that the impact energy absorption capacity in this other embodiment is reduced by the amount that the top plate portion 21A of the energy absorbing member 21 is spaced apart from, and does not abut against, the top plate portion 11A of the outer rocker member 11. However, by reducing the distance, the reduction in impact energy absorption capacity can be reduced.

[0032] <Still Another Embodiment> Figure 19 shows still another embodiment. In this still another embodiment, a pair of flanges 22C of the energy absorbing member 22 are fixed by welding to a fixing member 223, and the fixing member 223 is spaced apart from the top plate portion 12A of the inner rocker member 12 without abutting against it. The other configurations of this still another embodiment are the same as those of the first embodiment, and therefore a repeated description of the same parts will be omitted.

[0033] In yet another embodiment, the energy absorbing member 22 installed within the space of the locker 10 is smaller in width than the energy absorbing member 20 in the one embodiment. The energy absorbing member 22 is fixed by welding a top plate portion 22A to the top plate portion 11A of the outer locker member 11. A fixing member 223 joined to a flange portion 22C of the energy absorbing member 22 does not abut against the top plate portion 12A of the inner locker member 12, but is positioned slightly spaced apart.

[0034] As described above, in this yet another embodiment, the fixing member 223 to which the flange 22C of the energy absorbing member 22 is joined is spaced apart from, and does not abut, the top plate 12A of the inner rocker member 12. This reduces the occurrence of defective products due to manufacturing errors. That is, this prevents a manufacturing error in which the widthwise dimension W1 of the energy absorbing member 22 is larger than the widthwise dimension W2 of the interior space of the rocker 10, making it difficult to join the flange 11C of the outer rocker member 11 and the flange 12C of the inner rocker member 12. Therefore, this yet another embodiment improves manufacturing yield and reduces manufacturing costs compared to the first embodiment. Note that the impact energy absorption capacity in this yet another embodiment is reduced by the amount that the fixing member 223 to which the flange 22C of the energy absorbing member 22 is joined is spaced apart from, and does not abut, the top plate 12A of the inner rocker member 12. However, by reducing the distance, the reduction in impact energy absorption capacity can be reduced.

[0035] Other Embodiments While specific embodiments have been described above, the present disclosure is not limited to those external appearances and configurations, and various modifications, additions, and deletions are possible. For example, while the above-described embodiments illustrate examples in which the impact absorbing structure is applied to a vehicle body locker, the present disclosure can also be applied to center pillars, bumpers, and other components in addition to lockers. Furthermore, while the pair of vertical wall portions are arranged parallel to each other in the above-described embodiments, the pair of vertical wall portions may have an inclined shape in which the flange side is spaced apart from the top plate side.

[0036] Finally, the effects of other embodiments in the "Means for Solving the Problems" section above will be described.

[0037] According to another embodiment of the present disclosure, the pair of vertical wall portions are arranged parallel to each other, which makes it easier to position the energy absorbing member in accordance with the portion of the collision area of ​​the vehicle body that is most likely to absorb the collision load, compared to when the pair of vertical wall portions are formed in an inclined shape with the flange portion side spaced apart from the top plate portion side.

[0038] According to another embodiment of the present disclosure, the ratio of the fourth dimension to the third dimension of the hat shape is appropriately set so that when the energy absorbing member is subjected to a collision load, the pair of vertical wall portions of the energy absorbing member do not deform so as to bend in the same direction, but rather deform in opposing directions and come into contact with each other, thereby achieving the expected deformation that results in subsequent crushing.

[0039] In order for the energy absorbing member to undergo the expected deformation when subjected to a collision load, the fourth dimension of the hat-shaped energy absorbing member needs to be somewhat larger than the third dimension. Therefore, a long and narrow forming die is required to press-form the energy absorbing member. According to another embodiment of the present disclosure, the hat-shaped energy absorbing member is formed from two members joined at the top plate portion. Therefore, a long and narrow forming die is not required to press-form the energy absorbing member, making manufacturing easier.

[0040] According to another embodiment of the present disclosure, the deformation strength of the vertical wall portion that receives the collision load from the top plate portion toward the flange portion of the energy absorbing member can be appropriately increased by the bead. Therefore, the amount of energy absorbed by the energy absorbing member can be appropriately controlled. Furthermore, the plate thickness of the energy absorbing member can be reduced by the amount of reinforcement provided by the bead, thereby reducing the weight of the energy absorbing member.

[0041] The various embodiments described in detail above with reference to the accompanying drawings are exemplary of the present invention and are not intended to limit the scope of the present invention. The detailed description teaches those skilled in the art how to make, use, and / or implement various aspects of the present teachings, but is not intended to limit the scope of the present invention. Furthermore, each of the additional features and teachings described above may be applied and / or used separately or in conjunction with other features and teachings to provide an improved vehicle body impact absorbing structure and / or method of making and using the same.

Claims

1. An impact absorbing structure for a vehicle body comprising an energy absorbing member having a hat-shaped cross section along the input direction of a collision load, the energy absorbing member comprising: a top plate portion, a pair of vertical wall portions, and a pair of flange portions, the top plate portion having plate surfaces arranged facing each other in the input direction, the pair of flange portions being fixed to a single fixing member that receives the collision load, each of the flange portions and each joint portion of the top plate portion relative to the pair of vertical wall portions having a curved shape, a first dimension which is the dimension in the extension direction of each of the flange portions in the curved shape of each joint portion of the top plate portion is equal to or greater than a second dimension which is the dimension in the extension direction of the top plate portion in the curved shape of each joint portion of the top plate portion, and the first dimension is equal to or greater than a predetermined value.

2. A shock absorbing structure for a vehicle body according to claim 1, wherein the pair of vertical wall portions are arranged parallel to each other.

3. A shock absorbing structure for a vehicle body as described in claim 2, wherein the ratio of a fourth dimension, which is the distance between the top plate portion and the fixed member, to a third dimension, which is the distance between the pair of vertical wall portions, is 1:7 to 1:2.

5.

4. A vehicle body impact absorbing structure according to any one of claims 1 to 3, wherein the energy absorbing member is composed of two members joined at the top plate portion of the hat shape.

5. A vehicle body shock absorbing structure as claimed in any one of claims 1 to 3, wherein the pair of vertical wall portions have a plurality of beads formed by concave or convex stripes extending in the direction in which the top plate portion and each of the flange portions face each other, along the extension direction of the energy absorbing member.

Images