JP4150286B2 - Body energy absorption structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an energy absorption structure for a vehicle body that absorbs impact energy input from an end of a side member.
[0002]
[Prior art]
An automobile (vehicle) is required to effectively buffer the impact force applied to the vehicle body at the time of a collision.
[0003]
Therefore, in an automobile, for the purpose of improving safety, as a structure that absorbs collision energy, an impact in which the side member buckles and deforms at the end of the side member that extends along the vehicle front-rear direction among members constituting the vehicle body. A structure has been proposed in which frame-shaped energy absorbing members that cause buckling deformation with a smaller load than the load are connected. This is because, when an impact with a load smaller than the load that deforms the side member is applied from the front or rear of the vehicle body, the energy absorbing member buckles and deforms (crashes), absorbs the impact energy, When an impact is applied, the side member is also buckled and deformed (crash) to absorb the impact energy (see, for example, Patent Document 1).
[0004]
By the way, if it is attempted to maintain a constant amount of side member crash stroke with the same structure, the length of the vehicle body becomes longer by the amount of the energy absorbing member. It is easy to change each part of the car body. If the length of the vehicle body is kept constant with the same structure, the side member crash stroke will be shortened.
[0005]
Therefore, as a method of installing the energy absorbing member, the end of the energy absorbing member on the side member side is inserted into the side member, the energy absorbing member is disposed in front of the side member, and the insertion end of the energy absorbing member is, for example, A technique has been proposed in which a bolt nut is used to fasten a side member of a side member near its insertion end (see, for example, Patent Document 2), and a part of the energy absorbing member is accommodated in the side member. [0006]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 5-185955
[Patent Document 2]
Japanese Utility Model Publication No. 4-72080
[Problems to be solved by the invention]
By the way, in order to effectively absorb the impact energy by the side member, the side wall of the end side of the side member (part where the crash stroke is formed) is seated while being continuously crushed into a wave shape by the transmitted load. It is desirable to yield.
[0009]
However, in the structure in which the energy absorbing member is supported by the side wall portion of the side member, the rigidity for supporting the energy absorbing member is added in the middle in the longitudinal direction of the side member, so the rigidity of the side member changes during the crash stroke. For this reason, the deformation of the wave shape that continues from the end of the side member that absorbs the impact energy is interrupted in the middle, or the crushing starts from the point where the energy absorbing member is fixed before the end of the side member, and the supported part Because of the high rigidity, the portion may remain crushed, and there is a problem that impact energy cannot be absorbed effectively using a preset crash stroke.
[0010]
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an energy absorption structure for a vehicle body that can absorb impact energy by effectively utilizing a crash stroke of a side member while suppressing the influence on the length of the vehicle body due to the arrangement of the energy absorption member. Is to provide.
[0011]
[Means for Solving the Problems]
In order to achieve the above object, an energy absorbing member is disposed in front of the end of the side member and a part thereof is inserted from the end of the side member into the inside. By adopting a configuration in which the end member is directly or indirectly supported and suppressing the influence on the vehicle body length by arranging the energy absorbing member, the side member is a load transmitted from the end of the side member. The deformation is not interrupted in the middle, the deformation does not start in the middle, and the deformation is not buckled.
[0012]
Further, in order to support the energy absorbing member with a simple structure in addition to the above-mentioned purpose, the supporting member is fixed to the inserted end of the energy absorbing member and receives a shock force from the front of the side member through the energy absorbing member. And a fixing part that is detachably fixed to the end face of the side member directly or indirectly, and a connection between the energy absorbing member and the inner surface of the side member, and the receiving part and the fixing part are connected to the receiving part. A configuration having a transmission part for transmitting the input impact to the fixed part is adopted.
[0013]
Further, in addition to the above-described purpose, a dimension that allows buckling deformation of the side member is provided between the transmission portion and the inner surface of the side member facing the support member so that the support member does not impair the deformation of the side member when the side member crashes. There was a gap.
[0014]
Furthermore, in order to easily obtain an energy absorbing member having a cross-sectional shape suitable for impact absorption in addition to the above-mentioned purpose, an aluminum extruded member formed into a cylindrical shape by extrusion molding was used as the energy absorbing member.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described based on a first embodiment shown in FIGS.
[0016]
FIG. 1 shows, for example, the structure of the front end of an automobile (vehicle) to which the present invention is applied. FIG. 3 shows a cross section taken along the line AA in FIG. The hollow side member which comprises is shown. For the side member 1, for example, a pair of left and right cylindrical members extending integrally from the front end portion of the vehicle body 2 to the rear end portion of the vehicle body 2 along the front-rear direction, for example, a cylindrical member having a square cross section is used. FIG. 1 and FIG. 3 show one of these, for example, the side member 1 on the right side in the vehicle width direction. Each of the end portions on the front side of each side member 1 is a crash zone α, that is, a portion where deformation (buckling deformation) occurs when the impact force of a predetermined value F2 or more is input from the front of the side member 1. It has become.
[0017]
On the other hand, reference numeral 5 in the figure denotes a front end constituent part assembled to the front end part of each side member 1. The front end component 5 includes, for example, a strip-shaped beam 7 that extends along the vehicle width direction that supports the bumper 6, and a pair of left and right sides that protrude toward the side members 1 from both sides of the inner surface of the beam 7 in the vehicle width direction ( A crash box 8 (corresponding to an energy absorbing member). For the crash box 8, a cylindrical member formed by extrusion molding, for example, a rectangular aluminum cylindrical member (extrusion member) formed by extrusion molding of an aluminum lump is used. Each crash box 8 is deformed to be crushed (buckling deformation) when an impact force F1 (<F2) of a load not less than a predetermined value smaller than the impact force F2 that deforms the side member 1 is input from the end. It is. In addition, each energy absorption member 8 is made into the cross-sectional shape suitable for shock absorption for every vehicle model by extrusion molding. Here, the crush box 8 has a square shape that can be freely inserted into the side member 1, specifically, a square hollow cross-sectional shape that is smaller than the cross-sectional shape of the side member 1.
[0018]
A part of the end of each energy absorbing member 8 on the side member 1 side is inserted from the end surface of each side member 1 into the inside. Specifically, when only the crash box 8 is crushed, each crash box 8 is inserted into the side member 1 by a length β corresponding to the remaining crushed portion. Then, using a support bracket 9 (corresponding to a support member: only one is shown), a seat member attached to each end face of each side member 1, here, an end face of each side member 1, for example, Upper and lower ends are supported by a flange member 11 projecting outward from the outer wall surface of the side member 1.
[0019]
Explaining this support structure, for example, a substantially U-shaped band plate member is used for the support bracket 9. Specifically, as shown in FIG. 2, the support bracket 9 includes, for example, a plate surface portion 12 extending in the vertical direction following the end surface of the crash box 8, and both the upper and lower end portions of the plate surface portion 12 on the side surface of the crash box 8. Accordingly, a plate surface portion 13 extending toward the beam 7 side and a pair of plate surface portions 14 projecting from the extending end of each plate surface portion 13 in the vertical direction are provided. Among these, the end surface of the crash box 8 is attached (fixed) to the center of the plate surface of the plate surface portion 12, and the support bracket 9 is also included in a part of the front end component 5. These support brackets 9 are side members together with the crash box 8 from the end face of each side member 1 until the plate surface portion 12 and the plate surface portion 13 abut against the seat portion 11a of the flange member 11 projecting from the plate surface portion 14 in the vertical direction. It is inserted into 1. Then, the overlapping plate surface portion 14 and seat portion 11a are detachably fastened by screwing a fastening means, for example, a bolt 16 into a nut 18 attached to the seat portion 11a from a through hole 17 formed in the plate surface portion 14. It is. As a result, the support bracket 9 is configured such that the plate surface portion 12 receives a shock input from the front of the side member 1 through the crash box 8 and the plate surface portion 14 is detachably fixed to the end surface of the side member 1. The plate surface portion 13 between the side surface of the crash box 8 and the inner surface of the side member 1 facing the crash box 8 serves as a transmission portion that transmits the impact from the receiving portion to the fixed portion. With the support bracket 9, the crash box 8 is directly supported on the end surface of the side member 1 while a part of the end side is housed in the side member 1. In addition, the length dimension of each plate surface portion 13 is set to β corresponding to the crushing remaining portion of the crash box 8, and the inside of the side member 1 surrounded by the plate surface portion 12 and the plate surface portion 13 is It is a storage portion for storing the buckled and deformed crash box 8. With this support structure, the crash box 8 is assembled in series with the end of the side member so as to protrude forward from the end of the side member except for the portion of the deformation allowance.
[0020]
Further, the gap γ between the side surface of the crash box 8 and each plate surface portion 13 opposed thereto is set to a dimension that allows buckling deformation of the crash box 8. Further, the gap δ between each plate surface portion 13 and the inner surface of the side member 1 facing this plate is dimensioned to allow the side member 1 to buckle. Thereby, both the crash box 8 and the side member 1 are in an environment in which buckling deformation occurs without interfering with other members.
[0021]
By assembling the crash box 8 as described above, an energy absorbing structure capable of exhibiting good shock absorption in both the crash box 8 and the side member 1 is provided.
[0022]
In other words, it is assumed that an impact of a predetermined value F1 (<F2) or more is input from the front surface of the bumper 6 due to, for example, a light collision. Then, as shown in FIG. 4, the rigidity of the crash box 8 cannot withstand the applied load, and the four side walls of the crash box 8 are buckled and deformed in a wave shape (axial compression deformation). ). By the buckling deformation of the crash box 8, the impact energy input from the front of the vehicle body is absorbed, and the impact from the front of the vehicle body is buffered.
[0023]
When the input is made from the front surface of the impact bumper 6 having a predetermined value 2 or greater than the predetermined value F1, the crash box 8 is first buckled and deformed in a wave shape as shown in FIG. The deformation at this time continues until the beam 7 hits the opening end of the side member 1. As a result, the side member 1 has a system for absorbing the impact energy by itself while storing the crash box 8 that is buckled and deformed therein.
[0024]
Next, when the rigidity of the side member 1 cannot withstand the input impact, the crash zone α of the side member 1 starting from the end face of the side member 1 undergoes buckling deformation as shown in FIG.
[0025]
Here, since the support bracket 9 directly supports the insertion end of the crash box 8 on the end surface of the side member 1, the entire crash stroke is maintained at a uniform rigidity, and the rigidity changes in the middle. There is no.
[0026]
For this reason, as shown in FIG. 5, in the crash zone α, buckling deformation that is continuously crushed from the end of the side member 1 into a wave shape occurs due to the load transmitted from the end face of the side member 1 (axial compression deformation). .
[0027]
In other words, the crash of the side member 1 is not interrupted in the middle of the crash stroke, the deformation does not start in the middle of the crash stroke, and the collapse of the side member 1 does not occur due to partial rigidity. Progress continuously. Thereby, the impact stroke is satisfactorily absorbed by fully utilizing the crash stroke of the side member 1.
[0028]
Therefore, by the support structure that directly supports the insertion end of the crash box 8 on the end surface of the side member 1, it is possible to absorb impact energy by effectively utilizing the crash stroke of the side member 1. In addition, the support structure that directly supports the end surface of the side member 1 suppresses the influence on the vehicle body length dimension due to the arrangement of the crash box 8, and the crash box 8 when the impact force F1 of a predetermined load is input. Can crash completely. In particular, since the crash box 8 is formed of an extruded member made of aluminum, it can easily have a cross-sectional shape suitable for shock absorption for each vehicle type, and can efficiently absorb impact energy.
[0029]
Further, the support to the end face of the side member 1 in the crash box 8 is simple because the substantially U-shaped support bracket 9 is used. In addition, since the support bracket 9 can be detached from the end face of the side member 1, when only the crash box 8 is deformed (damaged) due to a light collision, the support bracket 9 is attached to the crash box 8, the beam 7 and the bumper. 6 is removed from the side member 1 and replaced with the new front-end component 5 instead of the damaged front-end component 5, and the exchangeability is excellent. In particular, between the plate surface portion 13 of the support bracket 9 and the inner surface of the side member 1, and between the plate surface portion 13 and the side surface of the crash box 8, the gap amount that the deformed side member 1 and crash box 8 do not interfere with the plate surface portion 13. Therefore, in the event of a collision, both the crash box 8 and the side member 1 can promise good buckling deformation with excellent shock absorption.
[0030]
FIG. 6 shows a second embodiment of the present invention.
[0031]
This embodiment is a modification of the first embodiment. In this embodiment, the seat 11a of the support bracket 9 is not directly fixed to the end surface of the side member 1 as in the first embodiment, but the seat 11a of the support bracket 9 is indirectly fixed. It is a thing. Specifically, in this embodiment, for example, the seat 11a of the support bracket 9 is bolted with an inclusion fixed to the flange member 11 at the end of the side member 1, for example, a frame member 19 extending in the vertical direction. 16 is fastened to the seat portion 11 a of the flange member 11.
[0032]
Even if it does in this way, there exists an effect similar to 1st Embodiment. However, in FIG. 6, the same parts as those of the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.
[0033]
In addition, this invention is not limited to each embodiment mentioned above, You may implement in various changes within the range which does not deviate from the main point of this invention. For example, in the above-described embodiment, the support bracket formed by the U-shaped band plate member is used. However, the present invention is not limited to this, and the other end of the support box is used to support the insertion end of the crash box on the end surface of the side member. You may let them. In the above-described embodiment, the structure in which the crash box is provided at the front end of the side member is described. However, the present invention may be applied to a structure in which the crash box is provided at the rear end of the side member. . Moreover, although the example which used the crush box as an energy absorption member was given in embodiment mentioned above, you may use the energy absorption member comprised using not only this but another structure. In the above-described embodiment, the side member uses a cylindrical member having a square cross section, and the crash box uses a square cylindrical member having a smaller cross sectional shape than the side member. The member may be a cylindrical member having an octagonal cross section, and the crush box may be a cylindrical member having a round cross section that fits within the octagonal cylinder of the side member. By making the cross-sectional shape of the crush box substantially similar to that of the side member, the hollow portion of the side member can be used effectively, and the cross-sectional area of the crush box can be secured to absorb the necessary energy. It can have characteristics.
[0034]
【The invention's effect】
As described above, according to the first aspect of the present invention, when absorbing the collision energy while suppressing the influence on the length of the vehicle body due to the arrangement of the energy absorbing member, The deformation is not interrupted or does not start in the middle of the deformation, and the buckling deformation is performed while being continuously crushed from the end of the side member without being crushed.
[0035]
Therefore, the impact energy input from the front of the side member can be absorbed by effectively utilizing the crash stroke of the energy absorbing member and the side member.
[0036]
According to the second aspect of the present invention, there is an effect that the end into which the energy absorbing member is inserted can be supported by the side member end with a simpler support member structure.
[0037]
According to the third aspect of the invention, there is an effect that it is possible to promise a better buckling deformation of the side member.
[0038]
According to the fourth aspect of the present invention, it is possible to obtain an energy absorbing member having a cross-sectional shape suitable for shock absorption for each vehicle type more easily.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an energy absorption structure for a vehicle body according to a first embodiment of the present invention.
FIG. 2 is an exploded perspective view of the energy absorption structure.
3 is a cross-sectional view taken along line AA in FIG.
FIG. 4 is a cross-sectional view showing a state where only an energy absorber is deformed in response to a light collision.
FIG. 5 is a cross-sectional view showing a state where both the energy absorber and the side member are deformed due to a large collision. 2
FIG. 6 is a perspective view showing an energy absorption structure for a vehicle body according to a second embodiment of the invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Side member, 8 ... Crash box (energy absorption member), 9 ... Support bracket (support member), 12 ... Plate surface part (receiving part), 13 ... Plate surface part (transmission part), 14 ... Plate surface part (fixed part) 16 ... bolts, 17 ... through holes, 18 ... nuts.

Claims (2)

A side member extending along the longitudinal direction of the vehicle;
An energy absorbing member that is disposed in front of the end of the side member, with a part inserted from the end of the side member, and buckles and deforms when an impact force of a predetermined value or more is input from the front of the side member. When,
A support member that directly or indirectly supports the inserted end of the energy absorbing member on the end surface of the side member ;
The support member is fixed to the inserted end of the energy absorbing member, and receives a shock force from the front of the side member through the energy absorbing member, and can be directly or indirectly attached to the end surface of the side member. The receiving portion and the fixing portion are connected to each other through the fixing portion fixed to the energy absorbing member and the inner surface of the side member facing the energy absorbing member, and the shock input to the receiving portion is fixed. And a transmission part that conveys to the part,
An energy absorbing structure for a vehicle body, wherein a gap having a dimension that allows buckling deformation of the side member exists between the transmission portion and the inner surface of the side member facing the transmitting portion.   2. The energy absorbing structure for a vehicle body according to claim 1, wherein the energy absorbing member is an aluminum extruded member formed into a cylindrical shape by extrusion molding.

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