JP2004345466A - Body front frame structure - Google Patents

Abstract

An object of the present invention is to provide a vehicle body front skeleton structure capable of effectively inducing axial crushing of a skeleton member by input of a collision load and improving the efficiency of absorbing collision energy.
A skeletal member (2) that extends in the front-rear direction of a vehicle body and forms a vehicle body skeleton at a front part of a vehicle body has a substantially uniform rigidity in the vehicle front-rear direction, and has a greater rigidity in the vehicle width direction inside than in the outside. The outer shell member 20 having a closed cross-sectional structure, and a rigidity adjusting member 21 disposed inside the outer shell member 20 and having a rigidity that gradually increases from the front of the vehicle body toward the rear of the vehicle body. When a collision load is input, the skeletal member 2 is efficiently crushed by the stiffness adjusting member 21, and a large crush reaction force is secured by not providing a plurality of fragile portions on the outer shell member 20 itself, so that collision energy is efficiently increased. Can be absorbed.
[Selection diagram] Fig. 4

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a vehicle body front frame structure of a vehicle.
[0002]
[Prior art]
The skeletal structure at the front of the vehicle body has a skeletal member that extends in the front-rear direction of the vehicle body. This skeletal member deforms during a vehicle collision to absorb collision energy from the front and affect the cabin, which is the occupant's living space. Is to be reduced.
[0003]
Although the skeletal member can efficiently absorb energy by crushing in the axial direction by input of a collision load, conventionally, a plurality of bead portions are formed on the skeletal member at predetermined intervals along the axial direction, Axial crushing can be promoted (for example, see Patent Document 1).
[0004]
[Patent Document 1]
JP 2001-158377 A (page 4, FIG. 1)
[0005]
[Problems to be solved by the invention]
However, in such a conventional vehicle body front skeletal structure, the axial crush of the skeletal member can be stabilized by forming a plurality of beads in the axial direction of the skeletal member. Since the force is reduced, when a plurality of bead portions are formed, the absorption efficiency of the collision energy is reduced, and there is a possibility that the energy that cannot be absorbed by the skeleton member may increase the influence on the cabin.
[0006]
Therefore, the present invention provides a vehicle body front skeletal structure capable of effectively inducing axial crushing of a skeletal member by input of a collision load and increasing the efficiency of absorbing collision energy.
[0007]
[Means for Solving the Problems]
In the vehicle body front skeletal structure of the present invention, the skeletal members extending in the vehicle body front-rear direction and forming the vehicle body skeleton of the vehicle front part are provided with substantially uniform rigidity in the vehicle body front-rear direction and in the vehicle width direction. An outer shell member having a closed cross-sectional structure in which the inner rigidity is larger than that of the outer side, and a rigidity adjusting member disposed inside the outer shell member, the rigidity of which gradually increases discontinuously from the front of the vehicle toward the rear of the vehicle. It is characterized by having comprised.
[0008]
【The invention's effect】
In the vehicle body front skeletal structure of the present invention, when a collision load is input to the skeletal member due to a frontal collision or an oblique forward collision, the skeletal member is constituted by an outer shell member and a rigidity adjusting member disposed inside the outer shell member. The rigidity balance of the former outer shell member, that is, the rigidity of the outer shell member having a closed cross-sectional structure is made substantially uniform in the vehicle longitudinal direction, and the inner rigidity in the vehicle width direction is larger than that of the outer side. And the rigidity balance of the latter rigidity adjusting member, that is, the rigidity of this rigidity adjusting member is gradually increased discontinuously from the front of the vehicle toward the rear of the vehicle, so that the skeletal member is inwardly moved by the input load. Axial crush can be suppressed by suppressing bending deformation, and a plurality of fragile parts are not provided in the outer shell member itself, so that a large crush reaction force is secured and collision energy is efficiently absorbed. Door can be.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0010]
1 to 9 show a first embodiment of a vehicle body front skeleton structure of the present invention, FIG. 1 is an external perspective view of an automobile to which the vehicle body front skeleton structure of the present invention is applied, and FIG. 2 is a vehicle body front skeleton. FIG. 3 is a plan view schematically showing a skeletal structure of a vehicle body front part, FIG. 4 is an enlarged perspective view showing a front region of a front side member on a vehicle body front right side, and FIG. 5 is a vehicle body front part. FIG. 6 is a schematic view schematically showing a state in which a collision load in a straight-ahead direction and an oblique direction is input to the front side member. FIG. 7 (a) and 7 (b) are schematic plan views schematically showing a comparison with the case, FIG. 7 is an energy absorption characteristic diagram when a collision load is input in a straight traveling direction, and FIG. 8 is a front side obtained by inputting an obliquely forward collision load. In the case where the rigidity adjusting member is provided, By comparing the trunk if no (a) a plan view showing approximately the express ~ (d), FIG. 9 is an energy absorption characteristic diagram during the frontal oblique impact collision load input.
[0011]
The vehicle body front frame structure of the first embodiment is applied to a front side member 2 as a frame member shown in FIGS. 2 and 3 which constitutes a frame structure of the front compartments FC of the vehicle 1 shown in FIG. .
[0012]
As shown in FIGS. 2 and 3, a pair of front side members 2 are provided on both left and right sides of the front compartments FC, and are disposed substantially parallel to the front-rear direction of the vehicle body. A bumper reinforce 3, which forms the framework of the front bumper, is connected to the front end of the vehicle.
[0013]
An extension side member 6 which extends from the dash panel 4 to the lower surface side of the floor panel 5 is connected to the rear of each front side member 2. Side sills 7 are arranged in parallel, and the front ends of the extension side members 6 and the side sills 7 are connected by outriggers 8.
[0014]
Further, a hood ridge member 9 is provided substantially in parallel above each front side member 2 and outside in the vehicle width direction. A front end of the hood ridge member 9 which rises from a front end of the side sill 7 at a rear end of the vehicle body. It is connected to a pillar 10.
[0015]
A strut tower 11 is provided between the hood ridge member 9 and the rear end of the front side member 2 in the vehicle body.
[0016]
The front side member 2 is provided with a reinforcing portion A at an intermediate portion away from the front end by a predetermined distance, and a mounting bracket for mounting a power unit P (see FIG. 5) in which an engine and a transmission are combined with the reinforcing portion A. The front region 2F (see FIG. 3) is located forward of the reinforcing portion A, and the rear region 2R is located behind the reinforcing portion A. The front region 2F includes collision loads F1 and F2 from the front. Deformed to absorb collision energy.
[0017]
Here, in the first embodiment, as shown in FIG. 4, the front region 2F of the front side member 2 has a substantially uniform rigidity in the front-rear direction of the vehicle body, and the rigidity on the inner side in the vehicle width direction is higher than that on the outer side. An outer shell member 20 having a larger closed cross-sectional structure and a rigidity adjusting member 21 disposed inside the outer shell member 20 and having a stiffness that increases gradually discontinuously from the front of the vehicle toward the rear of the vehicle. .
[0018]
The outer shell member 20 is formed by joining, by spot welding or the like, both side flange portions of an inner plate 2b having a U-shaped cross section to the inner portion of a flat outer plate 2a over the entire length of the front side member 2, thereby forming a rectangular cross section. It is configured as a closed cross-section structure.
[0019]
The reinforcing portion A can be formed by joining a reinforcing plate to the inner plate 2b, or partially increasing the thickness of the inner plate 2b.
[0020]
As shown in FIG. 4, the rigidity adjusting member 21 has upper and lower surfaces 21 a and 21 b formed in a substantially triangular plane whose width in the vehicle width direction gradually increases from the front to the rear of the vehicle body, and the upper and lower surfaces 21 a and 21 b. An inclined surface 21c connecting the inside of the vehicle 21b in the vehicle width direction forms an approximately U-shaped cross section, and the outer portions 21d of the upper and lower surfaces 21a and 21b serve as outer walls of the outer shell member 20 formed in a rectangular cross section. To the outer plate 2a by laser welding or the like.
[0021]
In this case, the joining position of the outer portion 21d is selected so as not to interfere with the crushed bead deformed in a bellows shape when the outer shell member 20 is axially crushed.
[0022]
A discontinuous rigid portion of the rigidity adjusting member 21 in the longitudinal direction of the vehicle body is formed by a plurality of first fragile portions 22 formed on the upper and lower surfaces 21a and 21b of the rigidity adjusting member 21 at predetermined intervals in the longitudinal direction of the vehicle body. It is composed.
[0023]
The slits 22 are formed on the upper and lower surfaces 21a and 21b in the vehicle width direction, and each slit 22 gradually becomes longer from the front of the vehicle body to the rear of the vehicle body as the width of the upper and lower surfaces 21a and 21b changes. Each slit 22 is formed at an interval of １ ／ of the crush mode pitch of the front side member 2.
[0024]
Further, a rear end portion 21e of the vehicle body of the inclined surface 21c serving as an inner portion of the rigidity adjusting member 21 is joined to an inner wall 2c of the inner plate 2b as an inner wall of the outer shell member 20 by plug welding or the like.
[0025]
In this case, the rear end portion 21 e of the rigidity adjusting member 21 is joined to the reinforcing portion A of the front side member 2.
[0026]
Further, in this embodiment, a second fragile member that induces axial crush of the front side member 2 when an axial collision load is input is provided at the front end of the outer shell member 20, specifically, at the front end of the inner wall 2c of the inner plate 2b. A bead portion 23 is provided as a part. In this case, the bead portion 23 is formed in a vertical direction along a valley in the axial crush mode.
[0027]
According to the vehicle body front skeletal structure of the first embodiment having the above configuration, when the collision load F1 acts on the front end of the front side member 2 from the straight traveling direction due to a frontal collision as shown in FIG. The axial crushing starts from the front end of the front side member 2 by the bead portion 23 provided at the front end of the front side member 20.
[0028]
Then, the collision load F1 is also input to the rigidity adjusting member 21, and the rigidity adjusting member 21 is deformed by the input of the collision load F1 such that the slit 22 is crushed and the upper and lower surfaces 21a and 21b are shortened in the axial direction. Accordingly, the outer shell member 20 joined to the outer portion 12d of the rigidity adjusting member 21 is induced by the collapse of each slit 22, and is axially crushed as shown in FIG.
[0029]
If the stiffness adjusting member 21 is not provided, the input load F1 is applied to the entire front side member 2 in the process of crushing the front side member 2, so that the starting point of the deformation of the front side member 2 is not specified. When the rear end of the front side member 2 is deformed as described above, the rear end of the front side member 2 is easily broken, as shown in FIG. Can not be absorbed.
[0030]
On the other hand, in the present embodiment, the rigidity of the outer shell member 20 on the inner side in the vehicle width direction is made larger than that on the outer side, and the rigidity adjusting member 21 is provided inside the outer shell member 20, so that the The side member 2 can be crushed in the axial direction by suppressing the inward bending deformation by the input load F1, and a large crush reaction force is secured by not providing a plurality of fragile portions on the outer shell member 20 itself. The collision energy can be efficiently absorbed.
[0031]
Therefore, as shown in the energy absorption characteristics of FIG. 7, in the case of the present embodiment in which the rigidity adjusting member 21 shown by the solid line in FIG. The amount of collision energy absorbed by the front side member 2 can be increased.
[0032]
Next, as shown in FIG. 5 and FIG. 8A, when the collision load F2 acts on the front end of the front side member 2 from obliquely outward due to the oblique forward collision, even in this case, the rigidity adjusting member is used. As a result, the inclination change angle θ1 of the axial center in the process of collapsing the front region 2F of the front side member 2 changes when the rigidity adjusting member 21 is not provided as shown in FIG. It becomes smaller (θ1 <θ2) than the angle θ2.
[0033]
For this reason, when the rigidity adjusting member 21 is provided as shown in FIG. 8B, a more stable crush mode is generated as compared with the case where the rigidity adjusting member 21 of FIG. 8D is not provided. Can be.
[0034]
In other words, even in the case of the oblique forward collision, when the rigidity adjusting member 21 is not provided, the starting point of the deformation of the front side member 2 in the process of collapsing the front side member 2 is not specified, and the rear end side is not specified. As shown in FIG. 8 (d), the rear end side is inwardly bent, and the collision energy cannot be sufficiently absorbed.
[0035]
On the other hand, in the present embodiment, by providing the rigidity adjusting member 21, the front side member 2 can be axially crushed by the input load F2, and the outer shell member 20 itself does not have a plurality of fragile portions. Thereby, it is possible to secure a large crush reaction force and efficiently absorb the collision energy.
[0036]
Therefore, as shown in the energy absorption characteristics of FIG. 9, in the case of the present embodiment in which the rigidity adjusting member 21 shown by the solid line in FIG. The amount of collision energy absorbed by the front side member 2 can be made equal to or more than that, and the crush stroke can be increased.
[0037]
.
[0038]
By the way, the vehicle body front skeleton structure of the first embodiment has the upper and lower surfaces 21a and 21b formed in a substantially triangular planar shape whose width in the vehicle width direction gradually increases from the front to the rear of the vehicle body in addition to the above-described effects. Since the outer portions 21d of the upper and lower surfaces 21a and 21b are joined to the outer plate 2a of the outer shell member 20 having a rectangular cross section, the front side member 2 can be mounted without losing the rigidity balance in the vehicle width direction at the time of a frontal collision. The stiffness adjusting member 21 joined to the outer shell member 20 at the time of an oblique forward collision can control the crush mode of the outer shell member 20 to obtain a stable and highly efficient collision energy absorbing effect. Can be.
[0039]
Further, the rigidity portions of the rigidity adjusting member 21 that are discontinuous in the vehicle longitudinal direction are formed as a plurality of first fragile portions formed on the upper and lower surfaces 21a and 21b of the rigidity adjusting member 21 at predetermined intervals in the vehicle longitudinal direction. 22, when the front end of the outer shell member 20 is deformed, in addition to the deformation mode of the outer shell member 20, the inclination connecting the inner sides of the upper and lower surfaces 21 a and 21 b in which the slit 22 of the rigidity adjusting member 21 is formed. The surface 21c is easily deformed, and thereafter, the deformation can induce the deformation of the outer plate 2a of the outer shell member 20. Therefore, a stable and highly efficient collision energy absorbing effect can be obtained without causing the outer shell member 20 to break.
[0040]
Further, by forming the slit 22 extending in the vehicle width direction as the first fragile portion, the deformation of the inclined surface 21c of the rigidity adjusting member 21 can be surely generated, and the crush mode of the outer shell member 20 can be efficiently performed. Can be generated well. The first fragile portion is not limited to the slit 22, and may be configured as a portion having lower rigidity than other portions, for example, an uneven bead.
[0041]
Furthermore, since the vehicle body rear end 21e of the inclined surface 21c of the rigidity adjusting member 21 is joined to the inner wall 2c of the inner plate 2b of the outer shell member 20, the outer shell member 20 can be efficiently and stably moved from the front end during a collision. Can be absorbed.
[0042]
In particular, since the vehicle body rear end 21e of the rigidity adjusting member 21 is joined to the reinforcing portion A of the front side member 2, the rigidity adjusting member 21 reliably receives the collision loads F1 and F2, and moves the outer shell member 20 to the front end. Energy can be absorbed efficiently and stably.
[0043]
Further, a bead portion 23 is provided at the front end of the outer shell member 20 as a second weak portion that induces axial crush of the front side member 2 when an axial collision load is input. The shaft 20 can be efficiently and stably crushed from the front end.
[0044]
In the first embodiment, when the rigidity adjusting member 21 is fixed to the outer shell member 20, the outer members 21d of the upper and lower surfaces 21a and 21b are joined to the outer plate 2a as shown in FIG. As shown in FIG. 10 without limitation, the outer edge of the vehicle body of the outer portion 21d is bent over the entire length to form a flange portion 24, and this flange portion 24 is formed on the outer plate 2a of the outer shell member 20. It can be joined by spot welding or the like.
[0045]
By fixing the rigidity adjusting member 21 to the outer shell member 20 via the flange portion 24 as described above, when the shape of the inner plate 2b of the outer shell member 20 is polygonal as in this example, the front side member 2, the rigidity is increased due to the increase in the inner corners of the vehicle, and a difference in rigidity balance with the outer plate 2a occurs, so that the front side member 2 is likely to be laterally bent. And the rigidity balance of the inner and outer walls of the outer shell member 20 can be evenly approximated.
[0046]
In addition, by providing the flange 24, it is possible to easily and accurately perform positioning when fixing the rigidity adjusting member 21 to the outer plate 2a, and it is possible to use spot welding for fixing at that time. The fixing work of the rigidity adjusting member 21 can be simplified.
[0047]
Further, as shown in FIG. 11, the rigidity adjusting member 21 and the outer shell member 20 are fixed by providing a flange portion 24a divided by the slit 22, and joining the divided flange portion 24a to the outer plate 2a by spot welding. Can also.
[0048]
Even in this case, a low-cost and easy-to-manufacture structure can be provided similarly to the rigidity adjusting member 21 shown in FIG.
[0049]
12 to 14 show a second embodiment of the present invention, in which the same components as those in the first embodiment are denoted by the same reference numerals, and redundant description will be omitted. 13 is an enlarged perspective view showing a front area of the front side member, FIG. 13 is a developed view of a rigidity adjusting member, and FIG. 14 is a plan view of the rigidity adjusting member in an attached state.
[0050]
The main difference between the first embodiment and the vehicle body skeleton structure of the second embodiment is that, as shown in FIG. 12, the rigidity adjusting member 21 is a semi-cylinder having a substantially constant curvature in the vehicle longitudinal direction. In this case, the length of the plurality of slits 22 formed in the upper and lower surfaces 21a and 21b is gradually reduced from the front of the vehicle body to the rear of the vehicle body.
[0051]
That is, as shown in FIG. 13, the rigidity adjusting member 21 of this embodiment has a length on both sides of a rectangular plate member 25 having a longer side in the longitudinal direction of the vehicle as a whole. A slit 22 gradually shortening toward the rear of the vehicle body (upward in the drawing) is formed in a comb-like shape, and the plate material 25 is formed by rolling the plate material 25 into a semi-cylindrical shape in the width direction (the left-right direction in the drawing).
[0052]
A plurality of the slits 22 are formed at regular intervals in the vehicle longitudinal direction, and the interval is set to １ ／ of the crush mode pitch of the front side member 2.
[0053]
As shown in FIG. 14, the rear end portion 21e of the rigidity adjusting member 21 has a reaction force supporting member 26 having an inclined portion 26a inclined in the vehicle width direction with respect to the vehicle longitudinal direction (vertical direction in the figure). Is connected to the reinforced portion A of the outer shell member 20 via the
[0054]
Further, even in this embodiment, the outer shell member 20 is provided with a bead portion 23 as a second fragile portion at the front end of the inner wall 2c of the inner plate 2b.
[0055]
With the above structure, according to the vehicle body front skeleton structure of the second embodiment, similarly to the first embodiment, the front side member 2 starts to deform from the bead portion 23 at the front end, and the rigidity adjusting member 21 , And the axial crushing of the outer shell member 20 is promoted by the induction, so that a stable axial crushing mode can be generated in the front side member 2.
[0056]
The size of the semi-cylinder of the rigidity adjusting member 21 is set in advance so as not to interfere with the axially crushed portion when the outer shell member 20 is deformed.
[0057]
Further, in this embodiment, the rear end 21e of the vehicle body of the rigidity adjusting member 21 is connected to the reinforcing portion A of the outer shell member 20 via the reaction force support member 26 having the inclined portion 26a. By acting to receive the deformation generated at the rear end of the member 2, the crush mode of the front side member 2 can be stabilized, and the efficiency of absorbing the collision energy can be enhanced.
[0058]
By the way, the vehicle body front skeletal structure of the present invention has been described by taking the first and second embodiments as examples, but various other embodiments may be adopted without departing from the scope of the present invention. it can.
[Brief description of the drawings]
FIG. 1 is an external perspective view of an automobile to which a vehicle body front frame structure according to the present invention is applied.
FIG. 2 is a perspective view showing a skeleton structure of a front portion of the vehicle body in the first embodiment of the present invention.
FIG. 3 is a plan view schematically showing a skeletal structure of a front portion of the vehicle body in the first embodiment of the present invention.
FIG. 4 is an enlarged perspective view showing a front area of a front side member on the right front side of the vehicle body in the first embodiment of the present invention.
FIG. 5 is an image diagram schematically illustrating a state in which a collision load in a straight traveling direction and an oblique direction is input to a front portion of the vehicle body in the first embodiment of the present invention.
FIGS. 6A and 6B show a deformation state of a front area of a front side member due to a collision load input in a straight traveling direction according to the first embodiment of the present invention, with and without a rigidity adjusting member; FIGS. FIG.
FIG. 7 is an energy absorption characteristic diagram when a collision load is input in a straight traveling direction in the first embodiment of the present invention.
FIGS. 8A to 8D show the deformation of the front region of the front side member due to the input of a diagonally forward collision load in the first embodiment of the present invention, with and without the rigidity adjusting member. FIG.
FIG. 9 is an energy absorption characteristic diagram when an obliquely forward collision load is input in the first embodiment of the present invention.
FIG. 10 is an enlarged perspective view showing a front region of a front right side front member which is a modification of the first embodiment of the present invention.
FIG. 11 is an enlarged perspective view showing a front area of a front right side front member which is another modification of the first embodiment of the present invention.
FIG. 12 is an enlarged perspective view illustrating a front region of a front side member on a vehicle body front right side according to a second embodiment of the present invention.
FIG. 13 is a development view of a rigidity adjusting member according to the second embodiment of the present invention.
FIG. 14 is a plan view of a rigid adjustment member according to a second embodiment of the present invention in an attached state.
[Explanation of symbols]
1 vehicle 2 front id member (frame member)
2F Front area of front side member 2R Rear area of front side member 20 Outer shell member 21 Rigidity adjustment member 22 Slit (first fragile part)
23 Bead part (second vulnerable part)
24, 24a Flange portion 26 Reaction force support member 26a Inclined portion A Reinforced portion

Claims (9)

A skeleton member that extends in the front-rear direction of the vehicle body and forms a vehicle body skeleton at the front of the vehicle body,
An outer shell member having a closed cross-sectional structure in which the rigidity is substantially uniform in the vehicle longitudinal direction, and the rigidity in the vehicle width direction inside is larger than that in the outside;
A rigidity adjusting member disposed inside the outer shell member, the rigidity of which gradually increases discontinuously from the front of the vehicle toward the rear of the vehicle;
A vehicle body front skeleton structure characterized by comprising: While the outer shell member is formed in a rectangular cross section, the rigidity adjusting member has upper and lower surfaces formed in a substantially triangular shape whose width in the vehicle width direction gradually increases from the front to the rear of the vehicle body, and an outer portion of the rigidity adjusting member. The vehicle body front skeletal structure according to claim 1, wherein the outer shell member is joined to an outer wall of the outer shell member. 2. The rigid portion which is discontinuous in the longitudinal direction of the vehicle body of the rigidity adjusting member is a plurality of first fragile portions formed on upper and lower surfaces of the rigidity adjusting member at predetermined intervals in the longitudinal direction of the vehicle body. 3. The vehicle body front skeleton structure according to 2. The vehicle body front frame structure according to claim 3, wherein the first fragile portion is a slit extending in a vehicle width direction. The vehicle body front skeletal structure according to any one of claims 1 to 4, wherein a rear end of the vehicle body in an inner portion of the rigidity adjusting member is joined to an inner wall of the outer shell member. 6. The vehicle body according to claim 1, wherein a reinforcing portion is provided at a portion of the outer shell member corresponding to the vehicle body rear end of the rigidity adjusting member, and the vehicle body rear end of the rigidity adjusting member is joined to the reinforcing portion. The vehicle body front skeleton structure according to any one of the first to third aspects. The rigidity adjusting member has a semi-cylindrical shape having a substantially constant curvature in the longitudinal direction of the vehicle body, and a plurality of first fragile portions formed on upper and lower surfaces thereof have a length in a vehicle width direction from the front of the vehicle body. The vehicle body front frame structure according to any one of claims 1 to 3, wherein the length is gradually reduced toward a rear side of the vehicle body. The vehicle body rear end portion of the rigidity adjusting member is connected to a reinforcing portion of the outer shell member via a reaction force support member having an inclined portion inclined in the vehicle width direction with respect to the vehicle longitudinal direction. Or a vehicle body front frame structure according to 7. The vehicle body according to any one of claims 1 to 8, wherein a second fragile portion that induces axial crush of the skeleton member when an excessively large load in the axial direction is input is provided at a front end of the outer shell member. Front skeletal structure.

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