JP3183009B2 - Body front structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle body front structure including a front side member and a cross member.

[0002]

2. Description of the Related Art A pair of front side members disposed on both lower sides in an engine room at the front of a vehicle body require high rigidity because a heavy power unit is mounted thereon, and the weight is reduced. It is necessary to meet the demand, so it is formed in a pipe shape, a rein hose is provided inside, and the vicinity of the front ends of both front side members is connected by a cross member, so that the structure has increased rigidity (Japanese Unexamined Patent Publication No. 1-309881
Reference).

FIGS. 4 and 5 show an example of a conventional vehicle body front structure including a front side member and a cross member. A pair of pipe-shaped front side members 1 are disposed substantially parallel to the vehicle body center line. Each front portion 1a is disposed substantially horizontally at a predetermined height in the engine room, and a rear portion 1b is provided. Is welded to a dash panel 2 which is provided so as to be bent downward to define an engine room and a vehicle interior, and further dives under the lower end of the dash panel 2 to the vehicle interior side (right side in FIG. 4).
It extends almost horizontally. Both ends 3a (one not shown) of the front cross member 3 arranged in a direction orthogonal to the vehicle body center line are welded to the lower surface near the front end of the front part 1a of the front side members 1 on both sides. Have been. Thus, the rigidity is increased by connecting the front end sides of both front side members 1 with the front cross member 3.

[0004]

Therefore, in the above-mentioned conventional vehicle body front structure, the front end members of the left and right front side members 1 are connected by the front cross member 3, so that the front side members 1 Can be increased in strength against a load or the like. However, when a load is applied in the axial direction of each of the front side members 1 at the time of a collision or the like, the four face plates constituting the square pipe-shaped front side member 1 undergo compression buckling deformation, respectively. Since the lower face plate to which the end 3a of the cross member 3 is connected is restrained from compressive buckling at the front cross member connecting portion, buckling deformation is newly started from this connecting portion as a starting point (FIG. 5). On the other hand, since the other three face plates are not restrained, the deformation from the front end of the front cross member 1 continues (see the buckling waveform b in FIG. 5). As a result, as shown in FIG. 5, since the phases of the buckling waveform a of the lower face plate and the buckling waveform b of the other face plate do not match, bending buckling is likely to occur due to interference of forces. Therefore, there is a problem that the axial compression deformation as designed is difficult to occur.

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above problems, and has as its object to provide a vehicle body front structure that stably causes axial compression deformation of a front side member in a collision or the like.

[0006]

As a means for solving the above-mentioned problems, the present invention is directed to a method in which a vehicle body is provided on both lower sides in an engine room at a front portion of a vehicle body and substantially parallel to a vehicle body center line. And a square pipe-shaped front side member having four face plates, and provided so as to be substantially orthogonal to the vehicle body center line.
A vehicle body front structure including a cross member coupled to a lower surface plate in the vicinity, and a rear side surface of a coupling portion of the cross member coupled to the front side member inside each of the front side members. The partition member is fixed to the inner peripheral surface substantially on the same plane as the above.

[0007]

As described above, inside the front side member, the partition wall material is fixed to the inner peripheral surface on substantially the same plane as the vehicle body rear side surface of the connecting portion of the cross member connected to the front side member. Provided. As a result, when a compressive load acts in the axial direction of the front side member,
Each face plate of the front side member undergoes compressive buckling deformation. At this time, the cross member is coupled to the lower face plate, and inside the front side member,
Since the partition member provided on the same plane as the rear side surface of the cross member is provided, the compression buckling of each face plate is restrained at the cross member connecting portion where the partition member is provided. Therefore, each face plate of the front side member starts to deform starting from the position where the partition wall member is provided, and stable axial compression deformation occurs.

[0008]

1 to 3 show an embodiment of the present invention.
It will be described based on.

In the vehicle body front structure according to the present invention, a pair of square pipe-shaped front side members 11 (one not shown) are substantially parallel to the vehicle body center line on both lower sides in the engine room of the vehicle body front part. Are arranged and each front part 11
A dash is provided substantially horizontally at a predetermined height in the engine room, and a rear portion 11b is provided substantially vertically so as to be bent downward to define the engine room and the vehicle interior. It is welded to the panel 12 and extends substantially horizontally below the lower end of the dash panel 12 toward the vehicle interior (the right side in FIG. 1). Both ends 13a (one not shown) of the front cross member 13 arranged in a direction orthogonal to the vehicle body center line are welded to the lower surface near the front end of the front part 11a of the front side members 11 on both sides, respectively. Have been. Thus, the rigidity is enhanced by connecting the front end sides of both front side members 11 by the front cross member 13.

Inside the front side member 11, a bulkhead (partition wall) having a U-shaped cross section is provided on the same plane as the vehicle body rear side surface 13b of the connecting portion of the cross member 13 connected to the front side member 11. Material) 1
4 is attached to the inner peripheral surface of the front side member 11 by welding all around.

In FIG. 1, reference numeral 15 denotes a torque box, 16 denotes a suspension tower, and 17 denotes an apron upper member.

Next, the operation of this embodiment constructed as described above will be described. The front side member 11 disposed at the front part of the vehicle body is provided inside the front part 11a with a front cross member at the outer lower surface. The bulkhead 14 is entirely welded to the inner peripheral surface of the front portion 11a so that the end portion 13a of the front cross member 13 is flush with the side surface 13b of the front cross member 13 on the rear side of the vehicle body. When a load is applied to the front side member 11 from the front during a vehicle collision or the like, that is, when a compressive load is applied in the longitudinal direction of the front side member 11, Each face plate constituting the four faces of the member 11 undergoes compressive buckling deformation.

At this time, the lower face plate of the front portion 11a of the front side member 11 is
Are joined, compression buckling is restricted at this joint. Further, since the three face plates on both sides and the upper side of the front portion 11a are connected to the lower face plate by a bulkhead 14 provided on the same plane as the side surface 13b on the rear side of the vehicle body of the front cross member 13, these three face plates are connected. Compression buckling is also restrained at the connection with the bulkhead 14 in the two face plates.

Therefore, the front portion 11a of the front side member 11 that is compressed and buckled by a load from the front.
The compression buckling of each of the face plates is temporarily restrained at the joint portion of the front cross member 13, that is, at the installation position of the bulkhead 14. As a starting point, compression buckling is newly generated in each of the four face plates.

As a result, as shown in FIG. 3, the bulkhead 14 is provided at the joint between the front side member 11 and the front cross member 13 inside the front portion 11a. Since the phases of the buckling waveform a generated on the side face plate and the buckling waveform b generated on the upper and both side face plates match, a stable axial compression deformation can be achieved as compared with the case where the phases of the buckling waveforms do not match. appear.

[0016]

As described above, the vehicle body front structure according to the present invention is characterized in that the partition member is provided inside the front side member on the same plane as the vehicle body rear side surface of the cross member connected to the front side member. Are fixed to the inner peripheral surface, so that when an axial load is applied to the front side member, the starting points of the compressive buckling deformation acting on each surface of the front side member coincide with each other. Compression deformation can be caused, and bending buckling deformation of the front side member can be prevented.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a main part of one embodiment of a vehicle body front structure according to the present invention.

FIG. 2 is a sectional plan view of a front portion of a front side member in the embodiment.

FIG. 3 is an explanatory diagram showing a buckling waveform generated at a front portion of a front side member in the embodiment.

FIG. 4 is a perspective view showing a main part of a conventional vehicle body front structure.

FIG. 5 is an explanatory diagram showing a buckling waveform generated at a front portion of a front side member in the structure of FIG. 4;

[Explanation of symbols]

 11 Front Side Member 11a Front End 13 Front Cross Member 13a End 14 Bulkhead

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-1-3099881 (JP, A) JP-A-5-105118 (JP, A) JP-A-5-24558 (JP, A) JP-A-5-105 139242 (JP, A) JP-A-5-85402 (JP, A) JP-A-4-50083 (JP, A) JP-A 52-66018 (JP, U) JP-A 63-129676 (JP, U) Hira 2-108662 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) B62D 21/15 B62D 25/20

Claims (1)

(57) [Claims] 1. A vehicle body is disposed on both lower sides in an engine room at a front part of a vehicle body substantially in parallel with a vehicle body center line , and
Four and a front side member shaped square pipe having a face plate, provided to be substantially perpendicular to the body centerline, the lower surface of both ends in the near with the front of both front side members
A vehicle body front structure comprising a cross member respectively coupled to a plate , wherein the inside of each of the front side members is substantially flush with a vehicle body rear side surface of a coupling portion of the cross member coupled to the front side member. A vehicle body front structure, wherein a partition member is fixedly provided on the inner peripheral surface.