Collision energy absorption device for vehicle and method for manufacturing the same

Abstract

To provide a collision energy absorption device for a vehicle which absorbs a large amount of collision energy and can further stabilize an impact absorption mode.SOLUTION: A collision energy absorption device (10) for a vehicle comprises: an energy absorption member (20); and a shell body (30). The shell body (30) includes a lower shell (31) and an upper shell (40). The upper shell (40) includes a foot portion (41), a neck portion (42), and a head portion (43). The neck portion (42) has a double plate structure. At least the lower shell (31) and the head portion (43) are positioned on the anti-input side. At the moment of collision, the head portion (43) and the neck portion (42) having the double plate structure serve to inhibit vertical collapse of the energy absorption member (20) against a load on the input side.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an improvement in a vehicle collision energy absorbing device. [Background technology]

[0002] [Terminology explanation] "Roll forming", also known as roll molding, is a plastic processing method in which a roll forming machine with several sets of rolls is prepared, a metal sheet is inserted into the first roll, the metal sheet is gradually bent, and the desired cross section is obtained by the last roll.

[0003] "Press forming" is a plastic processing method in which a press equipped with a punch and a die is prepared, a metal plate is placed on the die, and the punch is moved relatively into the die to obtain a drawn product. Roll forming machines are large and expensive, while presses are smaller and less expensive.

[0004] The "input side" is the side on which an external force due to a collision is first applied. The "anti-input side" is the side that is last affected by the external force due to a collision.

[0005] [Prior Art] In recent years, electric vehicles are becoming more common. Many electric vehicles have battery cases placed under the floor. To extend the driving range, the battery cases are enlarged and reach the side sills. In order to protect the drive battery housed in the battery case, a collision energy absorbing device is provided around the side sill. 2. Description of the Related Art Conventionally, collision energy absorbing devices for vehicles having various structures have been proposed (for example, see Patent Document 1 (FIG. 2)).

[0006] Patent Document 1 will be explained with reference to the following figure. FIG. 18 is a diagram for explaining the basic configuration of a conventional vehicle collision energy absorbing device. As shown in FIG. 18, a cross frame 102 is connected to a side sill 101, which is a part of the vehicle body. A floor panel 103 is placed below this cross frame 102. A battery case 105 is disposed below this floor panel 103.

[0007] In addition, a first collision energy absorbing device 106 is attached to the underside of the side sill 101, and a second collision energy absorbing device 107 is attached between the side sill 101 and the battery case 105. Since the first collision energy absorbing device 106 and the second collision energy absorbing device 107 are separate from the battery case 105, it is possible to arbitrarily set the plate thickness and determine the shape.

[0008] Incidentally, the side sill 101 disclosed in Patent Document 1 is formed by combining a side sill outer 109 having flanges 108 attached to the top and bottom and a side sill inner 112 having flanges 111 attached thereto, and joining the flanges 108 and 111 together. Due to the presence of the joined flange portion 108 and flange portion 111, it is unavoidable that a gap T must be provided between the first collision energy absorbing device 106 and the second collision energy absorbing device 107.

[0009] When a collision force indicated by a white arrow is received, the first collision energy absorbing device 106 collapses first and absorbs the collision energy. When the collision force exceeds a certain value, the first collision energy absorbing device 106 collapses and approaches and comes into contact with the second collision energy absorbing device 107. After this contact, the second collision energy absorbing device 107 collapses and further absorbs the collision energy. In this way, the battery case 105 is protected.

[0010] However, the structure disclosed in Patent Document 1 has the following drawbacks. First, due to the presence of the gap T, the transmission of the collision force from the first collision energy absorption device 106 to the second collision energy absorption device 107 is not smooth. That is, if the gap T is small, the transmission is performed in a short time, but if the gap T is large, the transmission is delayed. As a result, the shock absorbing mode becomes unstable.

[0011] Next, the first collision energy absorbing device 106 is fixed to the side sill outer 109 with a bolt 113 . When the first collision energy absorbing device 106 receives the collision force indicated by the white arrow, the first collision energy absorbing device 106 rotates around the vicinity of the head 114 of the bolt 113. In FIG. 18, the first collision energy absorbing device 106 rotates clockwise. When rotating, the lower end of the first collision energy absorbing device 106 hits the second collision energy absorbing device 107, and the other portion of the first collision energy absorbing device 106 hits the second collision energy absorbing device 107 with some delay. In this way, since the first collision energy absorbing device 106 and the second collision energy absorbing device 107 are separated, the impact absorbing mode becomes even more unstable.

[0012] Stabilization of the impact absorption mode is important, and there is a demand for a vehicle collision energy absorbing device that can further stabilize the impact absorption mode. [Prior art documents] [Patent documents]

[0013] [Patent Document 1] Patent No. 7325475 Summary of the Invention [Problem to be solved by the invention]

[0014] An object of the present invention is to provide a vehicle collision energy absorbing device that can absorb a large amount of impact energy and further stabilize the impact absorbing mode. [Means for solving the problem]

[0015] The invention according to claim 1 is a vehicle collision energy absorption device that absorbs collision energy when a collision force is applied in one direction, The vehicle collision energy absorption device includes an energy absorbing member that is an elongated member extending in a direction perpendicular to the one direction and absorbs the collision energy in one direction, and a shell that encases the energy absorbing member. The shell body includes a lower shell that covers a lower portion of the energy absorbing member and an upper shell that covers an upper portion of the energy absorbing member, The upper shell, in a cross-sectional view, includes a foot portion that extends to the lower shell and encases the energy absorbing member, a neck portion located at the base of the foot portion, and a head portion located on the neck portion, the neck portion having a double plate structure, and at least the lower shell and the head portion are located on the anti-input side, In the event of a collision, the head portion and the neck portion having a double plate structure function to suppress the energy absorbing member from falling in the vertical direction in response to the input load.

[0016] The invention according to claim 2 is the vehicle collision energy absorbing device according to claim 1, The head and foot are fixed to a mounting surface formed on a part of the vehicle body or an accessory part of the vehicle body, and when viewed in cross section, the area surrounded by the head, neck, foot and mounting surface is a closed cross-sectional portion.

[0017] The invention according to claim 3 is the vehicle collision energy absorbing device according to claim 1 or 2, The energy absorbing member is a long material extending along the longitudinal axis of the vehicle, and is characterized in that it is a corrugated plate having alternating peaks and valleys arranged along the longitudinal axis, or a porous structure having a plurality of polygonal holes extending in the vehicle width direction.

[0018] The invention according to claim 4 is the vehicle collision energy absorbing device according to claim 1 or 2, the energy absorbing member includes a first energy absorbing member and a second energy absorbing member disposed adjacent to the first energy absorbing member; the first energy absorbing member buckles in one direction to absorb impact energy; The second energy absorbing member extends in a direction perpendicular to the one direction and absorbs impact energy by bending deformation.

[0019] The invention according to claim 5 is the vehicle collision energy absorbing device according to claim 1, The head is characterized in that, in cross section, it has the same width as the lower shell.

[0020] The invention according to claim 6 is the vehicle collision energy absorbing device according to claim 4, The first energy absorbing member is housed in the shell, and the second energy absorbing member is disposed outside the shell and next to the head.

[0021] The invention according to claim 7 is the vehicle collision energy absorbing device according to claim 4, The shell is characterized in that a convex portion or a concave portion, which serves as a starting point of deformation, is formed on the input side.

[0022] The invention according to claim 8 is the vehicle collision energy absorbing device according to claim 7, The convex portion or concave portion is formed at a portion that closes a groove of the second energy absorbing member.

[0023] The invention according to claim 9 is the vehicle collision energy absorbing device according to claim 1, The lower shell has a protruding portion extending toward the opposite input side, The upper shell has a folded flange portion that overlaps the protruding portion, and this folded flange portion is joined to the lower shell, or is joined to the lower shell via an inner plate that is a separate member and has a folded flange portion that overlaps the protruding portion.

[0024] The invention according to claim 10 is the vehicle collision energy absorbing device according to claim 2, The accessory is a battery case, and the vehicle body includes a battery case that houses a battery, The battery case includes a bottom plate that supports the battery, and a frame that surrounds the battery placed on the bottom plate, the frame including left and right side frames and cross members that are respectively disposed between the front and rear ends of the side frames, The side frame is characterized in that it is the vehicle collision energy absorbing device described in claim 2.

[0025] The invention according to claim 11 is the vehicle collision energy absorbing device according to claim 2, The mounting surface is an outer surface of a battery case that houses a battery.

[0026] The invention according to claim 12 is the vehicle collision energy absorbing device according to claim 2, the lower shell includes a downward extension extending downward along the mounting surface; The upper shell is characterized by having an upward extension that extends upward along the mounting surface.

[0027] The invention according to claim 13 is the vehicle collision energy absorbing device according to claim 1, The energy absorbing member, the lower shell and the upper shell are made of aluminum alloy plates.

[0028] The invention according to claim 14 is the vehicle collision energy absorbing device according to claim 1, the energy absorbing member includes a first energy absorbing member and a second energy absorbing member, The first energy absorbing member is characterized in that the plate thickness thereof is thicker than the lower shell and the upper shell.

[0029] The invention according to claim 15 is the vehicle collision energy absorbing device according to claim 14, The second energy absorbing member has a thickness smaller than that of the first energy absorbing member.

[0030] The invention according to claim 16 is the vehicle collision energy absorbing device according to claim 4, The first energy absorbing member is divided into a plurality of members for each of the second energy absorbing members, The present invention is characterized in that a stay is attached between adjacent first energy absorbing members, extending upward from the lower shell while penetrating the upper shell and being fixed directly or indirectly to the vehicle body.

[0031] The invention according to claim 17 comprises a step of manufacturing an energy absorbing member, a lower shell manufacturing process for manufacturing a dish-shaped lower shell that houses the energy absorbing member by press molding; an upper shell manufacturing process for manufacturing an upper shell having such a shape by roll forming, the upper shell being placed over the lower shell in which the energy absorbing member is housed, the upper shell including a foot portion extending to the lower shell in a cross-sectional view, a neck portion located at the base of the foot portion, and a head portion located above the neck portion; A neck joining process in which the double plate constituting the neck is joined by a laser beam or by an adhesive; and bonding the upper shell to the lower shell by a laser beam or by an adhesive to obtain a vehicle collision energy absorbing device. Effect of the Invention

[0032] In the invention according to claim 1, the shell housing the energy absorbing member is made up of a lower shell and an upper shell, and the upper shell includes the neck and the head. During a collision, the head and neck serve to suppress the vertical collapse of the energy absorbing member. The collapse is suppressed and the energy absorbing member is crushed from the input side to the anti-input side, so the amount of impact energy absorbed increases and the impact absorption mode becomes stable. That is, the present invention provides a vehicle collision energy absorbing device that has a high impact energy absorption amount and can further stabilize the impact absorption mode.

[0033] In the invention according to claim 2, the area surrounded by the head, neck, foot and mounting surface is a closed cross-section. The closed cross-section has a higher rigidity than an open cross-section. This closed cross-section with a higher rigidity maintains the position of the neck in the early stage of a collision.

[0034] In the invention according to claim 3, the energy absorbing member is a corrugated plate having alternating peaks and valleys or a porous structure having a plurality of polygonal holes. The corrugated sheet or polygonal hole forms a ridge extending in the vehicle width direction, and this ridge buckles when a load is applied from the side, so that a sufficiently large collision energy can be absorbed.

[0035] In the invention of claim 4, a first energy absorbing member which is a corrugated plate or a porous structure and which can absorb energy by buckling when a load is applied from the ridge direction, and a second energy absorbing member which is a longitudinal material having a groove or cavity and which can absorb energy by bending and deforming when a load is applied in the longitudinal direction, are housed in the shell so as to be perpendicular and adjacent to each other. By combining a first energy absorbing member and a second energy absorbing member, it becomes possible to set a variety of impact absorbing modes, including those for pole collisions.

[0036] For example, if the second energy absorbing member is placed on the input side, the impact force of a pole collision that applies a local load is dispersed by bending and deforming the second energy absorbing member, and this dispersed force is applied to the first energy absorbing member whose ridge in one direction buckles. All ridges of the first energy absorbing member from the input side to the opposite input side are crushed, improving the energy absorption performance.

[0037] Also, when the first energy absorbing member is placed on the input side, the second energy absorbing member can firmly hold the pole collision.

[0038] In the invention according to claim 5, the head is expanded to the same width as the lower shell. By increasing the width of the head portion, the rigidity of the head portion can be increased. Since the rigidity of the head portion is increased, the collapse of the vehicle collision energy absorbing device can be further suppressed. In addition, since the rigidity of the head is increased, the amount of collision energy absorbed by the head increases, and the collision energy absorbing performance of the vehicle collision energy absorbing device is improved.

[0039] In the invention according to claim 6, the first energy absorbing member is housed in the shell, while the second energy absorbing member is disposed outside the shell and beside the head. The head can be made smaller, which allows for the downsizing of roll forming equipment, and by differentiating the energy absorption performance of the first energy absorbing member and the second energy absorbing member, it is possible to respond to a wider variety of collision patterns. In addition, the first energy absorbing member and the second energy absorbing member begin to collapse simultaneously in parallel.

[0040] In the invention according to claim 7, the shell is provided with a convex portion or a concave portion which serves as a starting point of deformation. During a collision, the convex or concave portions begin to plastically deform preferentially. By providing an appropriate number of convex or concave portions in appropriate locations, the input side is crushed and deformed, making it possible to control the collision mode.

[0041] In the invention according to claim 8, the convex portion or the concave portion is formed at a portion that closes the groove of the second energy absorbing member. The second energy absorbing member can be easily molded with an open cross section, and a closed cross section is formed between the upper shell or the lower shell, thereby increasing strength and rigidity and increasing the amount of collision energy absorption.

[0042] In the invention according to claim 9, the upper shell or the lower shell has a protruding portion or a folded flange, and these are overlapped to form the shell body. The upper shell can be manufactured by roll forming, and the lower shell can be manufactured by press forming, which are inexpensive manufacturing methods that can reduce costs. In addition, the upper shell of a long material with a complex cross section and a head can be easily manufactured by roll forming, and the long lower shell can be easily manufactured by press forming.

[0043] In the invention according to claim 10, the function of the vehicle collision energy absorbing device of the present invention is added to a side frame of a battery case which is an accessory to the body of an EV (electric vehicle). By using the side frame as a single component to serve as the vehicle collision energy absorbing device, the manufacturing costs of the vehicle collision energy absorbing device can be reduced compared to manufacturing the side frame and the vehicle collision energy absorbing device separately.

[0044] In the invention according to claim 11, the mounting surface is the side wall of the battery case. In other words, a closed cross section surrounded by the side wall, the head, the neck, and the upper shell is added. Since the side frame is reinforced with a vehicle collision energy absorption device, it is possible to make the side frame thinner and more compact, thereby making the battery case lighter.

[0045] In the invention according to claim 12, the lower shell is provided with a downward extension portion extending downward, and the upper shell is provided with an upward extension portion extending upward. Mounting parts such as brackets can be reduced, and the downward extension and the upward extension are joined to the mounting surface, but because the downward extension and the upward extension are separated vertically, the vehicle collision energy absorption device is stably supported on the mounting surface and the vehicle collision energy absorption device is effectively prevented from tilting up and down during a collision.

[0046] In the invention according to claim 13, the energy absorbing member, the lower shell and the upper shell are made of an aluminum alloy. Since the aluminum alloy plate is lightweight, it is possible to reduce the weight of the energy absorbing member. In addition, by carrying out an appropriate heat treatment, the strength can be improved, providing an energy absorbing member with excellent performance in absorbing collision energy.

[0047] In the invention according to claim 14, the energy absorbing member is composed of a first energy absorbing member and a second energy absorbing member, and the plate thickness of the first energy absorbing member is made thicker than the lower shell and the upper shell. Increasing the plate thickness improves the energy absorption performance of the first energy absorbing member. Also, by making the lower and upper shells thinner, the vehicle collision energy absorption device can be made lighter. By making the lower and upper shells out of steel plate to give them ductility and making the energy absorbing member out of aluminum alloy (hereafter abbreviated as aluminum alloy) to give it rigidity, the variety of collision modes can be increased.

[0048] In the invention according to claim 15, the plate thickness of the second energy absorbing member is made thinner than that of the first energy absorbing member. If the second energy absorbing member is placed on the input side, the second energy absorbing member will crush, followed by the first energy absorbing member. However, since the second energy absorbing member is thin and has low strength, it will crush quickly, so that the members will collapse sequentially from the input side, which will help stabilize the collision mode.

[0049] In the invention according to claim 16, the first energy absorbing member is divided into a plurality of members in the longitudinal direction (vehicle length direction) for one second energy absorbing member. By dividing the first energy absorbing members, a stay can be disposed between adjacent first energy absorbing members. The stays can connect the lower shell to the vehicle body or vehicle body accessories. Even if the vehicle collision energy absorbing device extends long along the longitudinal axis of the vehicle, the stays allow the vehicle collision energy absorbing device to be stably attached to the vehicle body.

[0050] The manufacturing method of a vehicle collision energy absorption device according to claim 17 includes a step of manufacturing an energy absorbing member, a step of manufacturing a lower shell by press molding, a step of manufacturing an upper shell by roll forming, a step of joining the neck portion by a laser beam or an adhesive, and a step of joining other portions of the neck by a laser beam or an adhesive. Vehicle collision energy absorption devices can be manufactured at low cost using general-purpose technologies such as press molding, die forming, and laser welding (or bonding). Manufacturing is easy because the energy absorption material can be sandwiched between the lower and upper shells and integrated. [Brief description of the drawings]

[0051] [Figure 1] 1 is a cross-sectional view of a vehicle collision energy absorbing device according to the present invention. [Diagram 2] 2 is a perspective view of an energy absorbing member which is one of the main elements of the vehicle collision energy absorbing device. FIG. [Diagram 3] 4(a) and 4(b) are diagrams illustrating the operation of the vehicle collision energy absorbing device. [Figure 4] 1(a) to 1(c) are diagrams illustrating advantages of the vehicle collision energy absorbing device according to the present invention. [Diagram 5] FIG. 11 is a perspective view showing a modified example of the energy absorbing member. [Figure 6] 1 is a cross-sectional view of a vehicle collision energy absorbing device including first and second energy absorbing members. [Figure 7] FIG. 4 is a perspective view of a second energy absorbing member. [Figure 8] 5(a) to 5(c) are diagrams illustrating the functions of the first and second energy absorbing members. [Figure 9] 4 is another cross-sectional view of the vehicle collision energy absorbing device including first and second energy absorbing members. FIG. [Figure 10] 6(a) and 6(b) are diagrams illustrating a modified example of the vehicle collision energy absorbing device. [Figure 11] 10A and 10B are diagrams illustrating a modified example of the vehicle collision energy absorbing device. [Figure 12] 6(a) to 6(c) are diagrams illustrating a modified example of the vehicle collision energy absorbing device. [Figure 13] FIG. [Figure 14] 14 is a cross-sectional view taken along line 14-14 of FIG. 13. [Figure 15]FIG. 1A is a diagram for explaining a modified example of the vehicle collision energy absorbing device, and FIG. [Figure 16] 10A and 10B are diagrams illustrating a modified example of the vehicle collision energy absorbing device. [Figure 17] FIG. 4 is a flow diagram illustrating a manufacturing method of the vehicle collision energy absorbing device. [Figure 18] FIG. 1 is a diagram illustrating a basic configuration of a conventional vehicle collision energy absorbing device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0052] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will now be described with reference to the accompanying drawings. EXAMPLES

[0053] Hereinafter, with reference to Figs. 1 to 5, a configuration and operation of a vehicle collision energy absorbing device 10 that is attached to a vehicle body and absorbs collision energy when a collision force is applied to the vehicle will be described.

[0054] [Vehicle collision energy absorption device] As shown in FIG. 1, a vehicle collision energy absorbing device 10 is attached to a vehicle body in a form in which it is housed in a side sill 11, for example. The vehicle collision energy absorbing device 10 mainly comprises an energy absorbing member 20 and a shell 30 that encases the energy absorbing member 20 .

[0055] [Shell] The shell 30 is a hollow body whose main elements are a lower shell 31 that covers the lower part of the energy absorbing member 20, and an upper shell 40 that covers the upper part of the energy absorbing member 20. Details of the energy absorbing member 20 will be described with reference to FIG.

[0056] [Lower shell] The lower shell 31 is a dish-shaped tray having a cross section of an approximately Z-shape, an L-shape, a U-shape, or the like, and is manufactured by press molding from a single metal plate (aluminum alloy or steel plate).

[0057] [Upper shell] The upper shell 40 comprises a pair of feet 41 that extend to the lower shell 31, a neck 42 located at the base of the feet 41, and a head 43 located above the neck 42, and has an octopus shape in cross section. The upper shell 40 has a somewhat complicated shape, but is manufactured by roll forming from a single metal plate.

[0058] [Neck] The neck portion 42 is a double-plate structure in which two metal plates are joined together with deposited metal 44 by laser welding or the like. Because it is a double-plate structure, the neck portion 42 has sufficient strength and rigidity, and has the advantage that it is less likely to lose its shape between the head and the neck portion 42 even when subjected to an external force.

[0059] [Part of the vehicle body or an accessory part of the vehicle body] The part of the vehicle body is, for example, a side sill 11. The side sill 11 is a hollow body formed by joining a side sill outer member 12 and a side sill inner member 13 together. In this example, the lower shell 31, foot portion 41 and head portion 43 are fixed to the side sill inner 13 by welding via an inner plate 14 of appropriate thickness and size.

[0060] The inner plate 14 may be omitted, and the lower shell 31, the foot portion 41 and the head portion 43 may be fixed directly to the side sill inner 13 by welding. That is, at least the lower shell 31 and the head portion 43 are fixed to the vehicle body (for example, the side sill inner 13) directly or indirectly via the inner plate 14.

[0061] [Closed section] One surface of the inner plate 14 (or the inner surface of the side sill inner 13) becomes a mounting surface 15 formed on a part of the vehicle body or an accessory part of the vehicle body, and the lower shell 31, the foot 41 and the head 43 are fixed to this mounting surface 15. At this time, the area surrounded by the head 43, the neck 42, the foot 41, and the mounting surface 15 becomes the closed cross-sectional portion 45. Compared to an open cross-sectional area, the closed cross-sectional portion 45 has high strength and rigidity. Due to the high strength and rigidity of the closed cross-sectional portion 45, the position of the neck 42 is maintained during a collision process.

[0062] [Energy absorbing material] 2, the energy absorbing member 20 is an elongated member extending along the vehicle's longitudinal axis 21. This elongated member is preferably a corrugated plate having alternating peaks 22 and valleys 23 arranged along the vehicle's longitudinal axis 21.

[0063] Since it is a corrugated plate, it has ridges perpendicular to the longitudinal axis 21 of the vehicle, and in the event of a side collision such as a collision with a pole, the ridges buckle to absorb energy. The energy absorbing member 20 can absorb a sufficiently large collision energy.

[0064] [Effect] In FIG. 3(a), in the case of a pole collision, it is assumed that a pole 16 collides with the vehicle collision energy absorbing device 10 as indicated by a white arrow. As shown in FIG. 3(b), mainly the ridges of the energy absorbing member 20 buckle and plastically deform, and the lower shell 31 and the upper shell 40 stabilize the plastic deformation, thereby absorbing the collision energy.

[0065] As shown in FIG. 3(a), head 43 is made of a relatively thin metal plate, but has large length and width dimensions, and therefore has high strength and rigidity as indicated by the section modulus and second moment of area. Furthermore, since the neck portion 42 has a double plate structure, it has a certain degree of strength.

[0066] The operation will be supplemented based on Figs. 4(a) to (c). Suppose that, as shown in FIG. 4( a ), upper shell 40 does not have a neck portion 42 , and is composed of foot portion 41 and U-shaped head portion 43 .

[0067] In an actual collision, the white arrow is often shifted up or down relative to the horizontal, or is slightly tilted. For example, a component force of a collision load is applied upward (or downward) to the vehicle collision energy absorption device 10 due to tilt. Then, as shown in FIG. 4(b), the U-shaped head 43 is easily deformed, and as a result, the vehicle collision energy absorbing device 10 falls upward (or downward).

[0068] 4(c), in the embodiment of the present invention, collapse is suppressed by the supporting action between the head portion 43 and the neck portion 42, particularly the supporting action of the neck portion 42. As a result, collapse is suppressed, and the ridges of the vehicle collision energy absorption device 10 buckle and collapse (plastically deform) over their entire length, absorbing the collision energy.

[0069] That is, in FIG. 3(a), the presence of the head portion 43 and the neck portion 42 prevents the foot portion 41 and the lower shell 31 that house the energy absorbing member 20 from falling over.

[0070] As a result, as shown in FIG. 3(b), the vehicle collision energy absorption device 10 does not collapse vertically (even if it does collapse, it is sufficiently suppressed) and the energy absorbing member 20 undergoes plastic deformation.

[0071] At this time, the presence of the closed cross-sectional portion 45 contributes to improving the rigidity of the vehicle collision energy absorption device 10 and plays a role in promoting stable plastic deformation of the vehicle collision energy absorption device 10 .

[0072] [Example of change in energy absorbing material] 5, the energy absorbing member 20 may be a porous structure or a honeycomb structure having a plurality of polygonal holes 25 having a polygonal cross section including a rectangular cross section. In either case, the holes form ridges at the corners. That is, the energy absorbing member 20 is an elongated member extending along the longitudinal axis 21 of the vehicle, and has a plurality of polygonal holes 25 extending in a direction perpendicular to the longitudinal axis 21 of the vehicle (the vehicle width direction).

[0073] Because it is a porous structure or a honeycomb structure, it is sufficiently lightweight. Despite its light weight, it has a ridge line in the direction perpendicular to the longitudinal axis 21 of the vehicle (the vehicle width direction), and can buckle to absorb a sufficiently large collision energy.

[0074] The following describes modified examples of the vehicle collision energy absorbing device 10. In the following description, the same components as those in Fig. 1 are designated by the same reference numerals as in Fig. 1, and detailed description thereof will be omitted.

[0075] [Modification 1 of vehicle collision energy absorption device] As shown in FIG. 6, the energy absorbing member 20 comprises a first energy absorbing member 26 and a second energy absorbing member 27 arranged so as to be in contact with or adjacent to the first energy absorbing member 26, and the second energy absorbing member 27 is arranged on the input side (outer side in the vehicle width direction). The first energy absorbing member 26 may be the one illustrated in FIG. 2 or FIG.

[0076] [Second energy absorbing member] As shown in FIG. 7, the second energy absorbing member 27 is an elongated member having a groove 28 with an open cross section (or a cavity with a closed cross section) extending along the longitudinal axis 21 of the vehicle.

[0077] [Effect of Modification Example 1] As shown in FIG. 8(a), the pole 16 collides with the vehicle collision energy absorbing device 10 as indicated by the white arrow.

[0078] FIG. 8(b) is a view taken along the arrow bb in FIG. 8(a). The pole 16 first hits the second energy absorbing member 27 at a point. It bends and deforms, and the impact force is distributed along the longitudinal axis 21 of the vehicle in the shape of a tree arrow. The distributed impact force is applied to the ridge of the first energy absorbing member 26.

[0079] 8(c), first, the ridge of the second energy absorbing member 27 buckles and collapses. The first energy absorbing member 26 comes into contact with the second energy absorbing member 27, and the first energy absorbing member 26 starts to collapse. By providing a difference in energy absorption performance between the buckling deformation of the ridgeline of the first energy absorbing member 26 and the bending deformation of the second energy absorbing member 27, it becomes possible to respond to a variety of collision patterns.

[0080] [Modification 2 of vehicle collision energy absorption device] As shown in FIG. 9, the energy absorbing member 20 comprises a first energy absorbing member 26 and a second energy absorbing member 27 arranged so as to be in contact with or adjacent to the first energy absorbing member 26, and the second energy absorbing member 27 is arranged on the anti-input side (the mounting surface 15 side).

[0081] Although the effect of dispersing the impact force as described with reference to FIG. 8(b) cannot be obtained, the second energy absorbing member 27 can reliably support the first energy absorbing member 26, and can promote buckling of the ridges. When the second energy absorbing member 27 is a groove, it can form a closed cross section with the upper or lower shell.

[0082] [Modification 3 of vehicle collision energy absorbing device] As shown in FIG. 10( a ), the width (width in the vehicle width direction) of the head 43 may be widened so that the neck 42 is located near the center of the head 43 in width. Furthermore, as shown in FIG. 10( b ), the width of the head portion 43 may be increased significantly so that it has the same width as the lower shell 31 .

[0083] It is possible to increase the strength and rigidity of the head portion 43 by increasing the width of the head portion 43. Since the strength and rigidity of the head portion 43 is increased, it is possible to further suppress the collapse of the energy absorbing member 20. In addition, since the rigidity of the head portion 43 is increased, the amount of collision energy absorbed by the head portion 43 increases, and the collision energy absorbing performance of the vehicle collision energy absorption device 10 is improved.

[0084] [Modification 4 of vehicle collision energy absorption device] As shown in FIG. 11, the first energy absorbing member 26 may be housed within the shell 30 and the second energy absorbing member 27 may be located outside the shell 30 and to the side of the head 43 .

[0085] In the configuration of Figure 6, the second energy absorbing member 27 collapses before the first energy absorbing member 26 begins to collapse. In contrast, in the configuration of FIG. 11, first energy absorbing member 26 and second energy absorbing member 27 begin to collapse simultaneously in parallel. Since the first energy absorbing member 26 and the second energy absorbing member 27 have different energy absorbing performances, it becomes possible to respond to a wider variety of collision patterns.

[0086] [Modification 5 of vehicle collision energy absorbing device] When the vehicle energy absorption device is applied to the side frame of a battery case, which is an accessory to the vehicle body, a convex portion 46 (or concave portion) that serves as the starting point of deformation may be provided at any location on the shell 30, as shown in Figure 12(a). During a collision, the protrusions 46 begin to undergo plastic deformation preferentially. By providing an appropriate number of protrusions 46 at appropriate locations, it becomes possible to control the collision mode.

[0087] [Modification 6 of vehicle collision energy absorbing device] As shown in FIG. 12(b), the convex portion 46 (or the concave portion) may be provided at a portion that closes the groove 28 of the second energy absorbing member 27. The groove 28 of the second energy absorbing member 27 and the bent portion of the convex portion 46 (or the concave portion) act as a trigger to start absorbing the collision energy, so that the control of the collision mode can be made more stable.

[0088] [Modification 7 of vehicle collision energy absorption device] As shown in FIG. 12(a), a lower shell 31 is provided with a protruding portion 32 extending toward the opposite input side. The upper shell 40 may be provided with a folded flange portion 47 that overlaps the protruding portion 32 , and this folded flange portion 47 may be joined to the protruding portion 32 of the lower shell 31 .

[0089] 12(c), a protruding portion 32 extending toward the opposite input side is provided on the lower shell 31. An inner plate 14 is prepared as a separate member having a folded flange portion 47 that is overlapped with the protruding portion 32. The folded flange portion 47 may then be joined to the protruding portion 32 of the lower shell 31.

[0090] The upper shell 40 can be manufactured with a complex cross section by roll forming, and the lower shell 31 can be manufactured inexpensively by press forming, so that the manufacturing cost can be reduced.

[0091] [Modification 8 of vehicle collision energy absorption device] FIG. 13 shows a battery case 50 to be mounted on the vehicle body. As shown in FIG. 13, the battery case 50 includes a bottom plate 52 that supports the battery 51, a frame body 53 that surrounds the battery 51 placed on the bottom plate 52, a lid 54 that covers the upper opening of the frame body 53, and a protective plate 55 that protects the cooler placed under the bottom plate 52.

[0092] The frame 53 is made up of left and right side frames 56, cross members 57 extending across the front and rear ends of the side frames 56, and sub-cross members 58 extending across the left and right side frames 56.

[0093] FIG. 14 is a cross-sectional view taken along line 14-14 in FIG. 14, the side frame 56 of the battery case 50 is the vehicle collision energy absorbing device 10 of the present invention. That is, the side frame 56 is also used as the vehicle collision energy absorbing device 10.

[0094] By using the side frame 56 of the battery case 50 as the vehicle collision energy absorption device 10, the manufacturing cost of the vehicle collision energy absorption device 10 can be reduced compared to manufacturing the side frame 56 and the vehicle collision energy absorption device 10 separately.

[0095] [Modification of vehicle collision energy absorption device 9] Alternatively, as shown in FIG. 15(a), the vehicle collision energy absorbing device 10 may be retrofitted to a side frame 56 of a battery case 50. That is, the mounting surface 15 of the vehicle collision energy absorbing device 10 may be the side wall of the battery case 50 or the outer surface of the side frame.

[0096] Since the side frame 56 is reinforced by the vehicle collision energy absorbing device 10, the side frame 56 can be made thinner and smaller, and the battery case 50 can be made lighter.

[0097] [Modification 10 of vehicle collision energy absorption device] As shown in FIG. 16, the lower shell 31 may be provided with a downward extension 33 that extends downwardly along the mounting surface 15, and the upper shell 40 may be provided with an upward extension 48 that extends upwardly along the mounting surface 15.

[0098] The downward extension 33 and the upward extension 48 are joined to the mounting surface 15. Since the downward extension 33 and the upward extension 48 are separated vertically, the vehicle collision energy absorption device 10 is stably supported by the mounting surface 15 and the vehicle collision energy absorption device 10 is effectively prevented from tilting up and down during a collision.

[0099] [Modification of vehicle collision energy absorption device 11] In FIG. 1, the energy absorbing member 20, the lower shell 31 and the upper shell 40 are preferably made of aluminum alloy plates. Since the aluminum alloy plate is lightweight, the weight of the energy absorbing member 20 can be reduced. In addition, by carrying out an appropriate heat treatment, the strength can be improved, and therefore the energy absorbing member 20 having excellent performance in absorbing collision energy can be provided.

[0100] [Modification 12 of vehicle collision energy absorbing device] As shown in FIG. 6, the energy absorbing member 20 is made up of a first energy absorbing member 26 and a second energy absorbing member 27. The plate thickness of the first energy absorbing member 26 is made thicker than the lower shell 31 and the upper shell 40 .

[0101] Increasing the plate thickness improves the energy absorption performance of the first energy absorbing member 26. In addition to making the first energy absorbing member 26 out of an aluminum alloy plate, the lower shell 31 and the upper shell 40 can be formed from a steel plate. Since steel plate has ductility, it is possible to stabilize the plastic deformation of the energy absorbing member.

[0102] [Modification 13 of vehicle collision energy absorption device] In FIG. 6, the plate thickness of the second energy absorbing member 27 is made thinner than that of the first energy absorbing member . When the second energy absorbing member 27 is disposed on the input side, the second energy absorbing member 27 is crushed, followed by the first energy absorbing member 26. Since the second energy absorbing member 27 is thin and has low strength, it is crushed quickly, so that the crushing occurs sequentially from the input side, facilitating the stabilization of the collision mode.

[0103] [Modification 14 of vehicle collision energy absorption device] FIG. 15(b) is a view taken along the line bb in FIG. 15(a) (partially omitted). As shown in FIG. 15(b), the first energy absorbing member 26 may be divided into a plurality of members for one second energy absorbing member 27.

[0104] By dividing the first energy absorbing members 26, a gap is created between adjacent first energy absorbing members 26, and a stay 59 can be disposed in this gap. 15(a), the stay 59 extends upward from the lower shell 31 while penetrating the upper shell 40, and is fixed to, for example, the side sill 11. The side sill 11 may be replaced by a part of the vehicle body or a vehicle body accessory.

[0105] Even if the vehicle collision energy absorbing device 10 extends long along the longitudinal axis of the vehicle, the vehicle collision energy absorbing device 10 is stably attached to the vehicle body by the plurality of stays 59.

[0106] [Method of manufacturing a vehicle collision energy absorption device] As shown in FIG. 17, for example, in step (hereinafter referred to as ST) 01, an energy absorbing member is manufactured, in ST02 a lower shell is manufactured and the energy absorbing member is joined to the lower shell, in ST03 an upper shell is manufactured, in ST04 a neck portion is joined, and in ST05 the upper shell is joined to the lower shell and the energy absorbing member, thereby manufacturing a vehicle collision energy absorption device. In addition, since the shell is divided into upper and lower halves, it is easy to accommodate and connect the energy absorbing members. ST01 to ST03 may be performed in reverse order or simultaneously in parallel.

[0107] [Energy absorbing material manufacturing process] For example, the energy absorbing member 20 shown in FIG. 2 is manufactured by bending a single aluminum alloy plate or steel plate.

[0108] [Lower shell manufacturing process] A single aluminum alloy plate or steel plate is press-formed to produce the dish-shaped lower shell 31 shown in FIG. If the press molding is used, the lower shell 31 can be manufactured at low cost.

[0109] [Top shell manufacturing process] The upper shell 40 shown in FIG. 1 is manufactured by roll forming a single aluminum alloy plate or steel plate. By roll forming, it is possible to form objects having complex shapes in a single stroke.

[0110] [Neck joining process] The double plate constituting the neck portion 42 shown in FIG. 1 is joined by a laser beam, or by adhesive, or by spot welding or riveting.

[0111] [Joining process] The energy absorbing member 20 is set at any position on the lower shell 31 and joined by a laser beam (welding) or by adhesive, and joining is performed from the open surface. Therefore, for example, space can be provided on the input side to make it easier to crush at the beginning of a collision, multiple energy absorbing members can be combined, and sufficient joining can be achieved by spot or linear welding, making it possible to integrate the shell body and the energy absorbing member 20.

[0112] According to the method of the present invention, the vehicle collision energy absorbing device 10 can be manufactured at low cost by using general-purpose techniques such as press molding, die forming, and laser welding (or bonding).

[0113] The present invention is suitable for a vehicle collision energy absorbing device attached to a vehicle body. [Explanation of symbols]

[0114] 10...vehicle collision energy absorption device, 14...inner plate, 15...mounting surface, 20...energy absorbing member, 21...longitudinal axis (longitudinal axis of vehicle), 22...peak, 23...valley, 25...polygonal hole, 26...first energy absorbing member, 27...second energy absorbing member, 28...groove, 30...shell, 31...lower shell, 32...projection portion, 33...lower extension portion, 40...upper shell, 41...foot portion, 42...neck portion, 43...head portion, 45...closed cross-section portion, 46...convex portion, 48...upper extension portion, 50...battery case, 51...battery, 52...bottom plate, 53...frame body, 56...side frame, 57...cross member, 59...stay.

Claims

1. A vehicle collision energy absorption device that is attached to a vehicle body and absorbs collision energy when a collision force is applied to the vehicle, The vehicle collision energy absorption device includes an energy absorbing member that is an elongated member extending in a direction perpendicular to the one direction and absorbs the collision energy in one direction, and a shell that encases the energy absorbing member. The shell body includes a lower shell that covers a lower portion of the energy absorbing member and an upper shell that covers an upper portion of the energy absorbing member, The upper shell, in a cross-sectional view, includes a foot portion that extends to the lower shell and encases the energy absorbing member, a neck portion located at the base of the foot portion, and a head portion located on the neck portion, the neck portion having a double plate structure, and at least the lower shell and the head portion are located on the anti-input side, A vehicle collision energy absorbing device, characterized in that, in the event of a collision, the head portion and the neck portion having a double plate structure function to suppress the energy absorbing member from falling in the vertical direction in response to an input load.

2. 2. The vehicle collision energy absorbing device according to claim 1, The head and foot are fixed to a mounting surface formed on a part of the vehicle body or an accessory of the vehicle body, and in a cross-sectional view, the area surrounded by the head, neck, foot and mounting surface is a closed cross-sectional portion.

3. 3. The vehicle collision energy absorbing device according to claim 1, The energy absorbing member is a long material extending along the longitudinal axis of the vehicle, and is a corrugated plate having alternating peaks and valleys arranged along the longitudinal axis, or a porous structure having a plurality of polygonal holes extending in the vehicle width direction.

4. 3. The vehicle collision energy absorbing device according to claim 1, the energy absorbing member includes a first energy absorbing member and a second energy absorbing member disposed adjacent to the first energy absorbing member; The first energy absorbing member buckles in one direction to absorb impact energy, The second energy absorbing member extends in a direction perpendicular to the one direction and absorbs impact energy by bending deformation.

5. 2. The vehicle collision energy absorbing device according to claim 1, A vehicle collision energy absorbing device, wherein the head portion has the same width as the lower shell in a cross-sectional view.

6. 5. The vehicle collision energy absorbing device according to claim 4, A vehicle collision energy absorption device, characterized in that the first energy absorbing member is housed in the shell, and the second energy absorbing member is disposed outside the shell and next to the head.

7. 5. The vehicle collision energy absorbing device according to claim 4, A vehicle collision energy absorbing device, wherein the shell is formed with a convex or concave portion on the input side, the convex or concave portion being a starting point of deformation.

8. 8. The vehicle collision energy absorbing device according to claim 7, The vehicle collision energy absorbing device, wherein the protrusion or recess is formed at a portion that closes a groove of the second energy absorbing member.

9. 2. The vehicle collision energy absorbing device according to claim 1, The lower shell has a protruding portion extending toward the opposite input side, The upper shell has a folded flange portion that overlaps the protruding portion, and this folded flange portion is joined to the lower shell, or is joined to the lower shell via an inner plate that is a separate member and has a folded flange portion that overlaps the protruding portion.

10. 3. The vehicle collision energy absorbing device according to claim 2, The accessory is a battery case, and the vehicle body includes a battery case that houses a battery, The battery case includes a bottom plate that supports the battery, and a frame that surrounds the battery placed on the bottom plate, the frame including left and right side frames and cross members that are respectively disposed between the front and rear ends of the side frames, 3. A vehicle collision energy absorbing device, comprising: a side frame; and a vehicle collision energy absorbing device according to claim 2.

11. 3. The vehicle collision energy absorbing device according to claim 2, 4. A vehicle collision energy absorbing device, comprising: a battery case for accommodating a battery;

12. 3. The vehicle collision energy absorbing device according to claim 2, the lower shell includes a downward extension extending downward along the mounting surface; 2 is a cross-sectional view of a vehicle collision energy absorbing device according to the first embodiment of the present invention;

13. 2. The vehicle collision energy absorbing device according to claim 1, 4. A vehicle collision energy absorbing device, comprising: an energy absorbing member, a lower shell, and an upper shell, the energy absorbing member being made of an aluminum alloy plate.

14. 2. The vehicle collision energy absorbing device according to claim 1, the energy absorbing member includes a first energy absorbing member and a second energy absorbing member, A vehicle collision energy absorbing device, wherein the first energy absorbing member has a plate thickness greater than those of the lower shell and the upper shell.

15. 15. The vehicle collision energy absorbing device according to claim 14, A vehicle collision energy absorbing device, wherein the second energy absorbing member has a plate thickness thinner than that of the first energy absorbing member.

16. 5. The vehicle collision energy absorbing device according to claim 4, The first energy absorbing member is divided into a plurality of pieces relative to the second energy absorbing member, A vehicle collision energy absorption device, characterized in that a stay is attached between adjacent first energy absorbing members, the stay extending upward from the lower shell while penetrating the upper shell and being fixed directly or indirectly to the vehicle body.

17. manufacturing an energy absorbing member; a lower shell manufacturing process for manufacturing a dish-shaped lower shell that houses the energy absorbing member by press molding; an upper shell manufacturing process for manufacturing an upper shell having such a shape by roll forming, the upper shell being placed over the lower shell in which the energy absorbing member is housed, the upper shell including a foot portion extending to the lower shell in a cross-sectional view, a neck portion located at the base of the foot portion, and a head portion located above the neck portion; A neck joining process in which the double plate constituting the neck is joined by a laser beam or by an adhesive; and joining the upper shell to the lower shell by a laser beam or by an adhesive to obtain a vehicle collision energy absorption device.

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