JP2004268635A - Vehicle body front structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicle body front structure capable of avoiding load concentration in the axial direction of a longitudinal skeleton members by dispersing a load at the time of a frontal collision, and preferably transmitting the load in the axial direction of the skeleton members in the fore/aft direction even if a collision with a low lap rate occurs. <P>SOLUTION: In each pair of the plurality pairs of the upper and lower longitudinal skeleton members 2, 3, 17, a curvature rate is applied to front end portions 2A, 3A, 17A of the longitudinal skeleton members in a vertical position relation in the same direction. Therefore, the front end portions 2A, 3A, 17A incline on the opposite side to a center P of the curvature rate when the front surface of the vehicle collides, curvature deformation gradually proceeds, and a collision contact area is increased in the curvature deformation direction, the load is dispersed in the increase direction thus, avoiding load concentration in the axial direction of the longitudinal skeleton members 2, 3, 17. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a vehicle body front structure of an automobile.
[0002]
[Prior art]
In the vehicle body front structure, the front end of the front side member, which is a longitudinal frame member, and the first cross member, which is a vehicle width direction frame member, are disposed via a crash box arranged on the axis of the front side member. In the event of a frontal collision of the vehicle, the crash box is crushed and deformed, thereby absorbing initial energy and stabilizing buckling deformation (axial crushing) of the front side member in the axial direction. (For example, see Patent Document 1).
[0003]
[Patent Document 1]
JP-A-2002-356179 (page 3, FIG. 4)
[0004]
[Problems to be solved by the invention]
In order to suppress the deformation of the cabin at the time of a frontal collision of the vehicle, energy absorption by axial crushing of the longitudinal frame member is effective as described above, but a load is applied in the axial direction of the longitudinal frame member at the time of a frontal collision. They tend to concentrate.
[0005]
On the other hand, at the time of a frontal collision of the vehicle, it is desired that both the own vehicle and the opponent vehicle be able to suppress the degree of damage to a small extent. Thus, the interaction may be insufficient due to the concentration of the axial load on the longitudinal frame member.
[0006]
Therefore, the present invention can disperse the load in the event of a frontal collision of the vehicle, avoiding the concentration of the load in the axial direction of the longitudinal frame member, and transmitting the axial load to the longitudinal frame member even in a collision with a small lap ratio. An object of the present invention is to provide a vehicle body front structure that can be favorably performed.
[0007]
[Means for Solving the Problems]
In the vehicle body front structure of the present invention, a plurality of pairs of longitudinal frame members extending in the vehicle longitudinal direction on both sides in the vehicle width direction are provided in a vertical direction,
The front ends of at least one pair of longitudinal frame members are connected to the rear surface of the vehicle width direction frame member extending in the vehicle width direction to connect the front ends,
It is characterized in that the front ends of the upper and lower longitudinal frame members are provided with a curvature in the same direction.
[0008]
【The invention's effect】
According to the present invention, a plurality of upper and lower pairs of longitudinal frame members are provided with a curvature in the same direction at the front end of the longitudinal frame members due to the vertical positional relationship, so that these front and rear frame members are positioned at the time of frontal collision of the vehicle. While the front end of the directional frame member is tilted to the side opposite to the center of curvature, the bending deformation gradually progresses, and the collision contact area increases in the bending deformation direction, and the load is dispersed in the increasing direction of the contact area.
[0009]
In particular, the front ends of at least one pair of front-rear skeleton members are coupled to the back surface of the vehicle width skeleton member so that the front end of the front-rear skeleton member contacts the rear surface of the vehicle width skeleton member. Since the bending deformation progresses and the collision contact area can be surely increased, by applying this to the main longitudinal skeleton member for absorbing collision energy, the axial direction of the main longitudinal skeleton member can be increased. Concentration of the load can be avoided, and the degree of damage to the front portion of the vehicle body can be reduced.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a perspective view showing a vehicle body frame structure to which a first embodiment of the present invention is applied, FIG. 2 is a perspective view showing a first embodiment of the present invention, and FIG. 3 is a front side member and a center cross in FIG. FIG. 4 is a plan view showing a main part of FIG. 3, FIG. 5 is an exploded perspective view showing a connecting portion between a front side member and a center cross member, and FIG. 6 is a line AA of FIG. 7, FIG. 7 is an exploded perspective view showing a different example of a coupling portion between the front side member and the center cross member, FIG. 8 is an exploded perspective view showing a coupling portion between a general portion and a curved portion of the front side member, 9 is a cross-sectional view taken along the line BB of FIG. 8, FIG. 10 is an exploded perspective view showing a different example of a coupling portion between a general portion and a curved portion of the front side member, and FIG. 11 is a first embodiment of the present invention. FIG. 12 is an explanatory view showing the operation of Is an explanatory view showing an operation of a comparative example against.
[0011]
As shown in FIG. 1, the vehicle body front structure according to the present embodiment has a front compartment F. A front side member 2 as a longitudinal frame member extending in the vehicle longitudinal direction is joined and disposed at the lower end of the hood ridge panel 1 constituting the left and right side walls of C.
[0012]
The front side member 2 serves as a main energy absorbing member at the time of a frontal collision of the vehicle and is formed in a closed cross section. The rear end of the front side member 2 extends from the dash panel 13 to the lower side of the floor panel 6 to serve as an extension side member. It has been extended to.
[0013]
At the upper end of the hood ridge panel 1, a hood ridge member 3 having a closed cross-sectional structure as a longitudinal frame member also extending in the longitudinal direction of the vehicle body is joined and arranged.
[0014]
The center cross member 4 and the upper cross member 5 as a vehicle width direction skeleton member having a closed cross-section structure are joined between the front end portions of the pair of left and right front side members 2 and between the front end portions of the pair of left and right hood ridge members 3. It is arranged.
[0015]
The cabin skeleton includes side sills 7 disposed on both left and right sides of the floor panel 6, roof side rails 9 disposed on both left and right sides of the roof panel 8, and is disposed vertically across the side sill 7 and the roof side rail 9. The front pillar 10, the center pillar 11, and the rear pillar 12 are provided, and the cowl box 14 is disposed at the upper end of the dash panel 13 so as to straddle the left and right front pillars 10.
[0016]
The front side member 2 is connected to the front end of the side sill 7 via an outrigger 14 at a portion connected to the extension side member.
[0017]
In the present embodiment, the rear end of the hood ridge member 3 is connected to a strut tower 1a which is a frame of the hood ridge panel 1, and is connected to the cowl box 14 and the front pillar 10 via the strut tower 1a. It is.
[0018]
In addition, front compartment F. At the bottom of C, a subframe 16 for mounting and supporting a power unit and the like is provided.
[0019]
The sub-frame 16 includes left and right side frames 17 as front and rear direction frame members, and a lower cross member 18 as a vehicle width direction frame member joined across front ends of the left and right side frames 17. The rear ends of the left and right side frames 17 are connected to each other by a rear frame 19 and are formed in a plane cross-girder shape.
[0020]
Each of the sub-frames 16 has a closed cross-sectional structure of each of the frames 17, 19 and the lower cross member 18, and connects the intermediate portion of the side frame 17 in the front-rear direction to the lower surface of the front side member 2 via a mounting member. The rear end of the side frame 17 is connected to the lower surface of the outrigger 14 via a mount member.
[0021]
The center cross member 4, the upper cross member 5, and the lower cross member 18 as the vehicle width direction frame members are disposed with their front end positions aligned vertically as shown in FIG. Are connected to each other by the stay member 20 of FIG.
[0022]
The front and rear frame members 2, 3, and 17 have their front ends connected to the rear surfaces of the vehicle width direction frame members 4, 5, and 18, respectively.
[0023]
The front and rear skeletal members 2, 3, and 17 have a front end portion extending from a curvature changing point K set at a position rearward of the vehicle body with respect to a front end portion of the skeleton members 2, 3, and 17 with respect to a connection portion with the vehicle width direction skeletal members 4, 5, and 18. And a curved portion 2A, 3A, 17A which is provided with a required curvature in the same direction with P as the center of curvature in the vertical positional relationship, and is provided with back surfaces 4a, 4a, A wedge-shaped open space S is formed between 5a, 18a and the wall surfaces of the curved portions 2A, 3A, 17A opposed thereto.
[0024]
In the present embodiment, each of the curved portions 2A, 3A, 17A is formed by curving inward from the curvature change point K in the vehicle width direction.
[0025]
3 to 10 show the front side member 2 and the center cross member 4 as the front-rear direction frame member and the vehicle width direction frame member, respectively, but the hood ridge member 3 and the upper cross member 5 are shown. , And the side frame 17 and the lower cross member 18 have the same structure.
[0026]
In the example shown in FIGS. 5 and 6, a flat T-shaped bracket 21 is fixed to the back of the center cross member 4 by bolts 22, and a curved portion 2A is formed on a plug portion 21B protruding from a side surface of a receiving piece 21A of the bracket 21. The center cross member 4 and the front side member 2 are joined together by fitting the terminal opening of the center cross member 4 to the receiving piece 21A.
[0027]
In the example shown in FIG. 7, a plurality of stud bolts 23 are provided on the back surface of the center cross member 4, and a bolt insertion hole 24 provided on the opposite surface of the curved portion 2 </ b> A is inserted through the stud bolt 23 so that a nut 25 is inserted. Thus, the center cross member 4 and the front side member 2 are connected.
[0028]
The curved portion 2A of the front side member 2 may be formed integrally with the general portion 2B. However, in the examples of FIGS. 8 to 10, the curved portion 2A is formed separately from the general portion 2B at, for example, a curvature change point K. Thus, it is connected to the front end of the general portion 2B.
[0029]
In the example shown in FIGS. 8 and 9, a small-diameter portion 2B ′ is formed at the front end of the general portion 2B with a step corresponding to the plate thickness, and the small-diameter portion 2B ′ is fitted into the rear terminal opening of the curved portion 2A. The bent portion 2A and the general portion 2B are joined by welding the insertion peripheral portion.
[0030]
In the example shown in FIG. 10, an end cover 26 having a plurality of stud bolts 27 protrudingly provided at a rear end of the curved portion 2A is fixed, while an end cover having a plurality of bolt insertion holes 28a provided at a front end of the general portion 2B. 28, and these bolt insertion holes 28a are inserted into the stud bolts 27, the end covers 26, 28 are butted together, and fastened with nuts 29 to connect the curved portion 2A and the general portion 2B. I have.
[0031]
On the other hand, the center cross member 4, the upper cross member 5, and the lower cross member 18, which are frame members in the vehicle width direction, connect at least the front ends of the front side member 2, the hood ridge member 3, and the front ends of the side frames 17 which are frame members in the front-rear direction. Are formed to be curved toward the rear of the vehicle body in plan view.
[0032]
According to the structure of the embodiment described above, the front side member 2, the hood ridge member 3, and the front end of the side frame 17, which are a pair of front and rear skeletal members arranged in the vertical direction, are provided with the vertical position. In this regard, the vehicle has the curved portions 2A, 3A, and 17A that are curved by imparting a curvature in the same direction, so that the front end portions of these longitudinal frame members fall to the opposite side to the center of curvature at the time of a frontal collision of the vehicle. The bending deformation progresses gradually, and the collision contact area increases in the bending deformation direction, and the load is dispersed in the increasing direction of the contact area.
[0033]
For example, in the front side member 2 which is a longitudinal frame member functioning as a main energy absorbing member at the time of a frontal collision of the vehicle, the front end thereof has a rear surface 4a of a center cross member 4 which is a vehicle width direction frame member. Since there is a wedge-shaped open space S between the rear surface 4a and the opposing wall surface of the curved portion 2A facing the rear surface 4a, when a frontal collision of the vehicle occurs, FIG. As shown in (B), as shown in (B), as the center cross member 4 retreats, the bending deformation gradually progresses while falling so that the opposing wall surface of the curved portion 2A comes into contact with the back surface 4a. Then, at the portion of the curved portion 2A opposite to the center of curvature P, the collision contact area SA surely increases from La to Lb in FIG. 11, and the load is dispersed in the increasing direction of the contact area SA to reduce the freon. Load in the axial direction of the side member 2 can be prevented from concentrating.
[0034]
FIG. 12 shows a comparative operation of the present invention. In this comparative example, the front side member 2 'is formed straight up to its tip, and this tip is attached to the back surface 4a' of the center cross member 4 '. In this comparative structure, when the center cross member 4 'retreats at the time of a frontal collision of the vehicle, the front side member 2' moves from the state shown in FIG. 12A to the state shown in FIG. In addition, the tip portion of the front side member 2 'is buckled and deformed in a bellows shape in the axial direction, and the collision contact area SA' of the front end of the front side member 2 'is almost the same as that before deformation as shown in FIG. Regardless, the load tends to concentrate in the axial direction of the front side member 2.
[0035]
In the present embodiment, the front ends of the hood ridge member 3 and the side frame 17 are also connected to the back surfaces of the upper cross member 5 and the lower cross member 18 so that the front side member 2 and the center cross member 4 are connected to each other. Since the structure is the same as that of the relationship, the effect of increasing the collision contact area can be surely performed in the hood ridge member 3 and the side frame 17 as well.
[0036]
As a result, in the early stage of the collision of the collision object M, the curved portions 2A, 3A, 17A are bent and deformed, and the bent portions 2A, 3A, 17A are bent and deformed to their curvature change points K, and subsequently the general portions 2B, 3B. , 17B start buckling deformation in the bellows shape in the axial direction, and efficiently absorb the collision energy by these bending deformation and axial crushing deformation.
[0037]
Moreover, as described above, the axial load concentration on the longitudinal frame members 2, 3, and 17 is avoided, so that the degree of damage to the front portion of the vehicle body can be suppressed to a small degree. Therefore, the degree of damage to the opponent vehicle can be relatively suppressed.
[0038]
Further, as described above, the curved portions 2A, 3A, and 17A are bent and deformed in the wedge-shaped open space S, so that the collision contact area can be increased on the open space S side. Even in the case of a collision with a small lap ratio between the directional frame members, the expansion of the collision contact area ensures that the axial load is transmitted to the longitudinal skeleton members 2, 3, and 17, thereby providing an efficient collision energy absorbing function. Can be demonstrated.
[0039]
In particular, in the present embodiment, since the curved portions 2A, 3A, 17A are formed by curving inward in the vehicle width direction from the curvature changing point K, the front and rear skeletal members 2, 3, 17 of the own vehicle are formed. On the other hand, even if the longitudinal frame member of the opponent vehicle is displaced outward in the vehicle width direction, the collision contact area is expanded outward in the vehicle width direction with time due to the bending deformation of the curved portions 2A, 3A, 17A. An axial load can be stably applied to the longitudinal frame members.
[0040]
In particular, in the present embodiment, since both end portions of the frame members 4, 5, and 18 in the vehicle width direction are formed to be curved toward the rear of the vehicle body in plan view, the collision contact toward the outside in the vehicle width direction is performed. The area can be expanded more favorably.
[0041]
In addition to such effects on the collision performance, the curved portions 2A, 3A, 17A are formed separately from the general portions 2B, 3B, 17B with the curvature change point K as a boundary. 2A, 3A and 17A can be easily formed with a curvature according to required characteristics.
[0042]
FIG. 13 shows a second embodiment of the present invention. In this figure, the front side member 2 and the center cross member 4 are representatively shown as a front-back direction frame member and a vehicle width direction frame member. The same structure is adopted for the ridge member 3 and the side frame 17.
[0043]
In the second embodiment, the curved portion 2A of the front side member 2 is formed by curving outward from the curvature change point K in the vehicle width direction, and other configurations are the same as those of the first embodiment. is there.
[0044]
Therefore, according to the structure of the second embodiment, the same operation and effect as those of the first embodiment can be obtained. However, in this embodiment, the wedge-shaped open space S is formed inside the vehicle width direction, and the curved portion is formed. Since the collision contact area is increased toward the center of the vehicle width due to the bending deformation of 2A, the front side member of the opponent vehicle is shifted toward the center of the vehicle width with respect to the front side member 2 of the own vehicle at the time of a frontal collision. In addition, an increase in the collision contact area on the vehicle width center side due to the bending deformation of the curved portion 2A allows the front side members to stably apply an axial load to each other.
[0045]
FIG. 14 shows a third embodiment of the present invention. In this figure, a front side member 2 and a center cross member 4 are shown as a front-back direction frame member and a vehicle width direction frame member. The same structure is adopted for the ridge member 3 and the side frame 17.
[0046]
In the third embodiment, the curved portion 2A of the front side member 2 is formed by curving upward from the curvature change point K, and other configurations are the same as those of the first embodiment.
[0047]
Therefore, according to the third embodiment, the same operation and effect as those of the first embodiment can be obtained. However, in this embodiment, the wedge-shaped open space S is formed on the lower side, and the bending deformation of the curved portion 2A is performed. Since the collision contact area is increased downward due to the collision, even if the front side member 2 of the opponent vehicle is shifted downward with respect to the front side member 2 of the own vehicle at the time of a frontal collision, the curved portion 2A Due to the increase in the area of the collision contact with the lower side due to the bending deformation, the axial load can be stably applied to the front side members.
[0048]
FIG. 15 shows a fourth embodiment of the present invention. In this figure, the front side member 2 and the center cross member 4 are representatively shown as a longitudinal frame member and a vehicle width direction frame member. The same structure is adopted for the ridge member 3 and the side frame 17.
[0049]
In the fourth embodiment, the curved portion 2A of the front side member 2 is formed by curving downward from the curvature changing point K, and the other configuration is the same as that of the first embodiment.
[0050]
Therefore, according to the structure of the fourth embodiment, the same operation and effect as those of the first embodiment can be obtained. However, in the present embodiment, the wedge-shaped open space S is formed on the upper side, and the bending of the curved portion 2A is performed. Since the collision contact area is increased upward due to the deformation, even if the front side member of the opponent vehicle is displaced upward with respect to the front side member 2 of the own vehicle at the time of a frontal collision, the bending of the curved portion 2A is performed. The axial load can be stably applied to the front side members due to the increase in the area of the collision contact upward due to the deformation.
[0051]
By the way, the vehicle body front structure of the present invention has been described by taking the previous embodiment as an example, but the present invention is not limited to this embodiment, and various other embodiments can be adopted without departing from the gist of the present invention.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a vehicle body skeleton structure of an automobile employing a first embodiment of the present invention.
FIG. 2 is a perspective view showing the first embodiment of the present invention.
FIG. 3 is a perspective view showing a front side member and a center cross member in FIG. 2;
FIG. 4 is a plan view showing a main part of FIG. 3;
FIG. 5 is an exploded perspective view showing a coupling portion between a front side member and a center cross member.
FIG. 6 is a sectional view taken along line AA of FIG. 5;
FIG. 7 is an exploded perspective view showing a different example of a coupling portion between a front side member and a center cross member.
FIG. 8 is an exploded perspective view showing a joint portion between a general portion and a curved portion of the front side member.
FIG. 9 is a sectional view taken along the line BB of FIG. 8;
FIG. 10 is an exploded perspective view showing a different example of a coupling portion between a general portion and a curved portion of the front side member.
FIG. 11 is an explanatory view showing the operation of the first embodiment of the present invention.
FIG. 12 is an explanatory view showing the operation of a comparative example with respect to the present invention.
FIG. 13 is a perspective view showing a front side member and a center cross member according to a second embodiment of the present invention.
FIG. 14 is a perspective view showing a front side member and a center cross member according to a third embodiment of the present invention.
FIG. 15 is a perspective view showing a front side member and a center cross member according to a fourth embodiment of the present invention.
[Explanation of symbols]
1: Food ridge panel 2: Front side member (front-back direction frame member)
2A: curved portion 2B: general portion 3: food ridge member (front-back direction frame member)
3A: curved portion 3B: general portion 4: center cross member (vehicle width direction frame member)
4a: back surface 5: upper cross member (frame member in the vehicle width direction)
5a ... back 16 ... sub-frame 17 ... side frame (front-back direction frame member)
17A: curved portion 17B: general portion 18: lower cross member (frame member in the vehicle width direction)
18a: Back FC, Front compartment K: Curvature change point S: Wedge-shaped open space P: Center of curvature

Claims (5)

A plurality of pairs of front-rear skeletal members extending in the vehicle front-rear direction on both sides in the vehicle width direction of the front compartment are provided in plural in the vertical direction,
At least one pair of front ends of the pair of front-rear skeletal members are connected to the back of a vehicle width direction skeletal member extending in the vehicle width direction to connect the front ends,
A front body structure in which the front ends of the upper and lower longitudinal frame members are provided with a curvature in the same direction. The vehicle body front part structure according to claim 1, wherein a curvature given to a front end portion of the frame member in the front-rear direction is made equal to an inner side in a vehicle width direction. The vehicle body front part structure according to claim 1, wherein a curvature given to a front end portion of the front-back direction frame member is made to coincide with a vehicle width direction outside. The vehicle body front part structure according to claim 1, wherein the curvature given to the front end part of the front-back direction frame member is made to coincide with the upward direction. The vehicle body front structure according to claim 1, wherein the curvature given to the front end of the frame member in the front-rear direction is made to match downward.

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