JP3555222B2 - Lower body structure of car - Google Patents

Description

[0001]
[Industrial applications]
The present invention relates to a lower body structure of an automobile having side frames extending in the front-rear direction on both sides of a vehicle body, and in particular, a side frame having an extension frame at an end.
[0002]
[Prior art]
Conventionally, in a vehicle provided with a pair of side frames extending in the vehicle longitudinal direction on both sides of the vehicle body, a front portion of the side frame is deformed when receiving a load in the vehicle longitudinal direction from the front to secure a crash space for absorbing impact. For this reason, various devices have been devised, and as one means, an extension frame is connected to an end of a side frame, and a crash space is formed by the extension frame portion.
For example, JP-A-3-
The front body structure of a vehicle described in Japanese Patent No. 79477 has a continuous extension frame at a front end of a side frame, and is extended rearward until a rear end of the extension frame overlaps with a front end of the side frame. Is inserted into the front end of the side frame and fixedly joined, so that the coupling rigidity is increased and the distance of the crash space, that is, the distance from the front end of the side frame to the front end of the extension frame can be easily changed. It is easy to manufacture a derivative car having the same basic structure / equipment and main specifications of the vehicle, but differing only in the crash space.
[0003]
[Problems to be solved by the invention]
However, in the above-described conventional vehicle front body structure, when the extension frame is deformed by an impact from the front, a crushed lump of the extension frame is present at the front end of the side frame, so that a crash space is reduced. The portion is occupied by the compaction of the extension frame, and there is a problem that the crash stroke, which is the distance from the front end of the side frame to the front end of the extension frame, cannot be used effectively.
[0004]
SUMMARY OF THE INVENTION An object of the present invention is to provide a lower body structure of a motor vehicle that includes a side frame and an extension frame at an end of the side frame and that can effectively use a crash stroke.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, a lower vehicle body structure of an automobile according to the present invention is a vehicle lower vehicle body structure having a front side frame extending in the vehicle front-rear direction on both sides of a front part of a vehicle body. The front frame of the front side frame has an extension frame connected to the front frame and an accommodation space into which a compact formed by crushing the extension frame by a load in the vehicle body longitudinal direction at the time of collision enters. The front side frame has a rectangular cross-section, a housing space is formed inside a front end portion that is formed higher than other portions behind, a front end opening with a lower side opened, and a front side frame. A lower end inclined opening that is inclined obliquely upward from the bottom toward the tip opening is formed, and a flat reinforcing member is provided on the outer surface of the tip. The auxiliary frame has a U-shaped cross section with an open top, a triangular side shape, and a front vertical edge portion that forms a vertically long rectangular opening that is continuous with the front end opening of the front side frame, and a lower end portion of the front side frame. A plate that includes an inclined upper edge joined to the inclined opening, and an auxiliary bottom surface that is continuous with the bottom surface of the front side frame, forms a lower half of the front end of the front side frame, and covers the opening in the vertically rectangular opening. Are joined, and the extension frame is joined to the plate, so that the pressure mass of the extension frame crushed by the load in the front-rear direction of the vehicle body enters the accommodation section of the front side frame, and the front side frame in the crash space Because it does not remain at the end of the crush stroke, the crush stroke can be used effectively.
When a load is applied in the vehicle front-rear direction, the accommodation space is formed at the front end of the front side frame, so that the internal space at the front end of the front side frame can be effectively used.
Further, at the front end of the front side frame, the end of the extension frame is fitted into the end of the front side frame, and the accommodation space is formed in the end of the front side frame on the vehicle body center side of the extension frame, The internal space at the front end of the front side frame can be used effectively, and when the load in the front-rear direction of the vehicle reaches a predetermined load, the pressure mass of the extension frame reliably enters the accommodation section of the front side frame, effectively reducing the crash stroke. Can be used.
In addition, by providing a flat reinforcing member on the outer surface of the tip, when receiving a load in the forward direction, deformation of the tip is suppressed, deformation of the auxiliary frame is large, and compaction of the auxiliary frame is smooth. Can enter the accommodation space.
Further, the front side frame has a rectangular cross section, a housing space is formed inside a front end portion formed higher than other portions behind, a front end opening with a lower side opened, and a front end from the bottom of the front side frame. By forming the lower end inclined opening obliquely upward toward the opening, when receiving a load in the forward direction, the front opening of the front side frame is enlarged along the lower end inclined opening, and the auxiliary frame is opened. The compact can smoothly enter the accommodation space.
[0006]
【Example】
A first embodiment of the present invention will be described with reference to FIGS.
In FIG. 3, a pair of side frames 1 provided on both sides of the vehicle body over substantially the entire length of the vehicle body, extending in the front-rear direction of the vehicle body, bending inward in the vehicle width direction at the front of the vehicle body, and narrowing the interval between the front ends. A pair of front side frames 1F which constitute a portion of the both side frames 1 at the front part of the vehicle body, an extension frame 2 respectively connected to the front ends of the front side frames 1F, and both ends joined to the front ends of the extension frames 2 and 2 A cross member 3 extending in the vehicle body width direction, a cross member 4 extending in the vehicle body width direction having both ends connected to bent portions of the side frames 1, 1 and both ends connected to a rear end of the bent portion of the side frames 1, 1 A front suspension cross member 5 extending in the vehicle body width direction and a vehicle body width direction in which both ends are connected to the side frames 1, 1 behind the bent portion. Side suspension cross member 6, a plurality of cross members 7, 8, 9, 10, extending in the vehicle width direction, both ends of which are connected to side frames 1, 1 behind rear suspension cross member 6, and both ends of cross member 4 A tension rod bracket 11 provided in the vicinity, a front suspension cross member bracket 12 to which both ends of the front suspension cross member 5 are connected, and a rear suspension cross member bracket 13 to which both ends of the rear suspension cross member 6 are connected. The lower vehicle body structure provided with is shown.
[0007]
In FIGS. 1 and 2, the front side frame 1F has a rectangular cross section, is formed higher than the other portion behind and has a front end portion (upper half) 1A in which a housing space is formed, and a mounting portion having a high side wall. 1B, a tip opening 1C provided at the tip and having a lower side opened, and a tip lower inclined opening 1D inclined obliquely upward from the bottom surface 1E of the front side frame 1F toward the lower end of the tip opening 1C. .
Plate-shaped side reinforcements 15 are joined to both outer surfaces of the distal end (upper half) 1A to reinforce the distal end 1A.
[0008]
The auxiliary frame 16 has a U-shaped cross section with an open top, a triangular side shape, and is disposed continuously to the front end opening 1C of the front side frame 1F to form a front end vertical side portion forming a vertically long rectangular opening. 16A, an inclined upper edge 16B joined to the lower end inclined opening 1D of the front side frame 1F, an auxiliary bottom surface 16C continuously arranged on the bottom surface 1E of the front side frame 1F, and a vehicle body provided on the auxiliary bottom surface 16C. A bead portion (fragile portion) 16D having a plurality of beads extending in the width direction, and an inclined upper edge 16B is joined to a tip lower inclined opening 1D of the front side frame 1F to form a lower half of the tip of the front side frame 1F. A part is formed.
[0009]
A plate 14 in which a mounting flange is formed to cover the opening is joined to a vertically long rectangular opening formed by joining the auxiliary frame 16 to the front side frame 1F, and the plate 14 is attached to the rear end of the extension frame 2. After being provided, the mounting flange 2A is joined, the both ends of the cross member 3 are joined to the front mounting flange 2B provided at the front end of the extension frame 2, and the bumper 20 is attached to the front surface of the cross member 3 via the bumper bracket 19. (See FIG. 4).
As an example, in the vehicle body structure of the van type vehicle shown in FIG. 4, 21 is a front pillar, 22 is an instrument panel, 23 is a column shaft, and 24 is a tire house.
[0010]
A pair of support plates 11A, 11A of the tension rod bracket 11 are joined and fixed to outer surfaces of both side walls of the front side frame 1F at a rear portion of the accommodation space formed at the front end portion 1A of the front side frame 1F and at a position immediately behind the accommodation space. The mounting plate 12A of the front suspension member bracket 12 is fixedly joined to the outer surface of the side wall of the front side frame 1F adjacent thereto, and the supporting plates 17 and 18 for connecting the support plate 11A and the mounting plate 12A are provided. Are joined.
[0011]
The support plate 11A of the tension rod bracket 11 covers the entire height of the side wall of the front side frame 1F and has a sufficient length in the front-rear direction of the vehicle body to reinforce the rear part of the accommodation space and the front side frame 1F immediately behind the accommodation space. The mounting plate 12A of the front suspension member bracket 12 has a size that covers the entire height of the side wall of the front side frame 1F.
[0012]
With the above configuration, when the extension frame 2 is crushed and retracted by the load from the front of the vehicle body, the auxiliary frame (lower half) 16 is deformed and compressed by the bead portion (fragile portion) 16D, and the tip lower end inclined opening is formed. 1D, the front end of the front side frame 1F is enlarged along the lower end inclined opening 1D, and the compressed mass of the retracted auxiliary frame 16 smoothly enters the accommodation space of the front end 1A. And the crash stroke can be used effectively (see FIG. 5).
In addition, since a flat side reinforcement 15 is joined to both outer surfaces of the tip (upper half) 1A and the tip (upper half) 1A is reinforced, a load from the front is received. At times, the deformation of the distal end portion (upper half) 1A is suppressed, the deformation of the auxiliary frame (lower half) 16 is large, and the compaction of the auxiliary frame 16 smoothly enters the housing space of the distal end portion 1A.
Furthermore, since the rear portion of the accommodation space and the front side frame 1F immediately after the supporting space are reinforced by the support plate 11A of the tension rod bracket 11 and the mounting plate 12A of the front suspension member bracket 12, the front end portion (upper portion) of the front side frame 1F The half portion) 1A and the rear portion of the housing space are suppressed from being deformed, and the compacted mass of the auxiliary frame 16 can be surely entered into the housing space of the front end portion 1A. Volume can be used effectively.
[0013]
A second embodiment will be described with reference to FIGS.
In FIG. 6, a side frame 30 having a substantially rectangular cross section and extending in the front-rear direction of the vehicle body is provided with a front-end enlarged portion 30A having a front-end enlarged above the other portion behind and having a housing space formed therein. And a rectangular opening 302
Is provided at the front end of the enlarged front end portion 30A.
The rear end 310 of the extension frame 31 having a rectangular cross section having a slightly smaller external dimension than the opening 302
And a bolt hole 303 (see FIG. 7) opened near the front end of the side wall 301 of the front end enlarged portion 30A, and a rear end portion 310 of the extension frame 31.
The extension frame 31 is connected to the side frame 30 by a fastening bolt 32 that penetrates a bolt hole 311 formed on the side wall of the extension frame 31.
[0014]
In operation, when the extension frame 31 is crushed by a load from the front and absorbs an impact, the extension frame 31 is connected to the side frame 30 by the fastening bolts 32. Is located in front of the side frame 30, but when the load from the front exceeds the breaking strength of the fastening bolt 32, the fastening bolt 32 breaks, and the compacted mass of the extension frame 31 can move backward. Opening 302
From above into the accommodation space in the enlarged end portion 30A (see FIG. 7).
[0015]
With this configuration, the pressure mass of the extension frame 31 reliably enters the accommodation space in the enlarged distal end portion 30A and is eliminated from the front of the side frame 30, that is, is eliminated from the crash space, so that the crash stroke can be used effectively. At the same time, the volume of the tip of the side frame 30 can be effectively used.
Also, by appropriately setting the breaking strength of the fastening bolt 32, the load at which the fastening bolt 32 breaks can be appropriately set.
Although only the structure at the front part of the vehicle body has been described, it is needless to say that the structure can be applied to the rear part of the vehicle body.
[0016]
【The invention's effect】
The present invention is configured as described above, and has the following effects.
The front frame is connected to the front end of the front side frame and extends in the front-rear direction of the vehicle, and the accommodation space into which a compact formed by crushing the extension frame by the load in the front-rear direction of the vehicle at the time of collision enters. By being provided at the front end of the side frame, the compaction of the extension frame crushed by the load in the front-rear direction of the vehicle body enters the accommodation section of the front side frame, and the compaction of the front side frame in the crash space. Since it does not remain at the end, the crush stroke can be used effectively.
When a load is applied in the vehicle front-rear direction, the accommodation space is formed at the front end of the front side frame, so that the internal space at the front end of the front side frame can be effectively used.
Further, at the front end of the front side frame, the end of the extension frame is fitted into the end of the front side frame, and the accommodation space is formed in the end of the front side frame on the vehicle body center side of the extension frame, The internal space at the front end of the front side frame can be used effectively, and when the load in the front-rear direction of the vehicle reaches a predetermined load, the pressure mass of the extension frame reliably enters the accommodation section of the front side frame, effectively reducing the crash stroke. Can be used.
In addition, by providing a flat reinforcing member on the outer surface of the tip, when receiving a load in the forward direction, deformation of the tip is suppressed, deformation of the auxiliary frame is large, and compaction of the auxiliary frame is smooth. Can enter the accommodation space.
Further, the front side frame has a rectangular cross section, a housing space is formed inside a front end portion formed higher than other portions behind, a front end opening with a lower side opened, and a front end from the bottom of the front side frame. By forming the lower end inclined opening inclined obliquely upward toward the opening, the front end opening of the front side frame is enlarged along the lower end inclined opening when receiving a load in the forward direction, and the auxiliary frame is opened. The compact can smoothly enter the accommodation space.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a first embodiment of the present invention.
FIG. 2 is an assembly view showing a first embodiment of the present invention.
FIG. 3 is a plan view showing a vehicle body structure to which the present invention is applied.
FIG. 4 is a side view showing an example of a vehicle body structure to which the first embodiment of the present invention is applied.
FIG. 5 is a side view showing the operation of the vehicle body structure to which the first embodiment of the present invention is applied.
FIG. 6 is a perspective view of a second embodiment of the present invention.
FIG. 7 is an assembly view of a second embodiment of the present invention.
[Explanation of symbols]
1 Side frame, 1A tip (upper half)
1F Front side frame, 2 extension frames
11 Tension rod bracket
12 Suspension cross member bracket, 16 Auxiliary frame (lower half) 16D bead (fragile)
30 side frame, 30A tip enlarged part, 31 extension frame, 32 fastening bolt

Claims (1)

In a lower body structure of a vehicle having a front side frame extending in the front-rear direction on both sides of a front part of a vehicle body, an extension frame connected to a front end of the front side frame and extending in the front-rear direction may collide with a front frame. At the front end of the front side frame, a housing space into which a compact formed when the extension frame is crushed by a load in the vehicle front-rear direction sometimes enters is provided,
The front side frame has a rectangular cross-section, a housing space is formed inside the front end portion formed higher than the other portion behind, and a front end opening with a lower side open, and a front end opening from the bottom of the front side frame. A lower end inclined opening that is inclined diagonally upward is formed, a flat reinforcing member is provided on the outer surface of the tip, and the auxiliary frame has a U-shaped cross section with an upper opening and a triangular side shape. The front vertical edge that is formed and forms a vertically-long rectangular opening continuously with the front opening of the front side frame, the inclined upper edge that is joined to the front lower inclined opening of the front side frame, and the bottom surface of the front side frame. And an auxiliary bottom surface, constituting a lower half of the front end of the front side frame, and a plate covering the opening is joined to the vertically rectangular opening, Vehicle bottom structure of which is characterized by extended frame plates are joined.

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