JP2002240739A - Vehicle body front part structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle body front part structure capable of restraining the deformation of a cabin front part and sufficiently absorbing energy at the time of offset collision. SOLUTION: A rear end part 9E of a sub frame 9 abuts on the front end part of a floor skeleton member 13 by the rotational displacement of the sub frame 9 at the time of the offset collision of the vehicle. Thus, reaction force is generated. Therefore, the deformation of the cabin front part can be restrained and an ideal energy absorbing property can be achieved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a vehicle body front structure of an automobile.

[0002]

2. Description of the Related Art As is well known in automobiles, in the event of a frontal collision of a vehicle, buckling deformation of front side members disposed in the front-rear direction of the vehicle body on the left and right sides of a power unit mounting room in front of the vehicle compartment, and support of the power unit. The collision energy is absorbed by the downward bending deformation of the sub-frame (Japanese Patent Laid-Open Nos. 9-86435 and 2000-2000).
-16327).

[0003]

In the case of an offset collision even at the time of a frontal collision of the vehicle, the collision load is concentrated on one side of the front part of the vehicle body, so that the amount of crushing deformation of the front part of the vehicle body tends to be larger than in the case of a full lap collision. is there.

[0004] Therefore, even if the amount of crushing deformation of the front portion of the vehicle body increases during the offset collision, it is necessary to increase the strength and rigidity of the front portion of the vehicle compartment in order to suppress the deformation of the front portion of the vehicle compartment. However, when the strength and rigidity of the front part of the vehicle compartment are increased, the reaction force in the latter half of the collision at the time of a full lap collision becomes too large, so that ideal energy absorption characteristics cannot be obtained.

Therefore, according to the present invention, the deformation of the front portion of the cabin is suppressed to be small during an offset collision, and good energy absorption characteristics can be obtained. On the other hand, the reaction force can be prevented from becoming too large in the late stage of the collision during a full lap collision. It is intended to provide a vehicle front structure.

[0006]

According to the first aspect of the present invention, the rear of the power unit mounting compartment separated from the front of the passenger compartment by the dash panel is mutually displaced by the displacement caused by the input at the time of the offset collision of the vehicle. A reaction force generating member that generates a reaction force by contact is provided.

According to a second aspect of the present invention, the reaction force generating member according to the first aspect is arranged so as not to abut against each other when the vehicle is displaced by an input during a full lap collision. .

[0008] In the invention of claim 3, claims 1 and 2
The reaction force generating member described in the above, a cross-shaped sub-frame in which the rear ends of both sides in the vehicle width direction are fastened and fixed to the lower surface side of the dash panel, close to the rear end of the sub-frame on the lower surface of the dash panel, And a floor frame member arranged to be offset inward in the vehicle width direction from the rear end.

According to a fourth aspect of the present invention, the floor frame member according to the third aspect extends in the vehicle longitudinal direction from the front end portion of the lower surface of the dash panel to the floor panel. And

According to a fifth aspect of the present invention, a front side member disposed in the vehicle longitudinal direction on the vehicle width direction outside of the floor frame member according to the fourth aspect, and straddling the floor frame member. A closed cross section is provided, and the rear end of the subframe is fastened and fixed to the lower surface of the closed cross section.

According to the invention of claim 6, claims 4 and 5 are provided.
The rear end portion of the floor frame member described in (1) is disposed so as to intersect with a cross member joined and arranged on the floor panel across side sills on both sides in the vehicle width direction.

According to the seventh aspect of the present invention,
A protrusion is provided on the front side of the floor frame member described in (1), which is capable of interfering with the rotational displacement of the rear end of the sub-frame inward in the vehicle width direction.

[0013]

According to the first aspect of the invention, when the vehicle collides with the vehicle in a frontal state in an offset state, the reaction force generating members are displaced and abutted by the collision input to generate a reaction force. Ideal energy absorption characteristics can be obtained by suppressing deformation of the portion to a small extent.

Further, since the overall strength and rigidity of the front part of the cabin are not increased by increasing the thickness of the dash panel or disposing the stiffener, the rear end of the collision at the time of a frontal collision in the full wrap state of the vehicle is not improved. The force can be prevented from becoming too large.

According to the invention described in claim 2, according to claim 1
In addition to the effects of the invention, the reaction force generating members do not come into contact with each other at the time of a full lap collision of the vehicle, so that the reaction force in the latter half of the collision can be reliably prevented from becoming excessive.

According to the third aspect of the present invention, in addition to the effects of the first and second aspects of the present invention, the sub-frame can be effectively used as one of the reaction force generating members, so that the cost can be advantageously obtained. At the same time, since the other of the reaction force generating members is configured as a floor frame member, the rigidity of the floor can be increased, and the deformation of the front portion of the cabin at the time of a vehicle frontal collision can be further reduced.

According to the invention described in claim 4, according to claim 3,
In addition to the effects of the invention, the floor frame member is disposed in the vehicle front-rear direction from the lower front end portion of the dash panel to the floor panel, so that the power unit can be moved backward by the floor frame member in the event of a vehicle front collision. This can enhance the effect of suppressing deformation of the front part of the vehicle compartment.

According to the invention set forth in claim 5, according to claim 4,
In addition to the effects of the invention, the fastening and fixing portion at the rear end of the sub-frame is a closed cross-section provided across the front side member and the floor frame member, so the strength and rigidity of the fixing portion at the rear end of the sub-frame And the mounting support rigidity of the power unit can be increased.

According to the sixth aspect of the invention, in addition to the effects of the fourth and fifth aspects, a collision input acting on the floor frame member at the time of a vehicle front collision is efficiently transmitted to the cross member, the side sill, and the like. And the load can be dispersed, and the floor rigidity can be further increased.

According to the seventh aspect of the present invention, in addition to the effects of the fifth and sixth aspects, the rearward displacement of the rear end of the sub-frame in the vehicle width direction at the time of an offset collision of the vehicle causes the rotational displacement of the rear end of the sub-frame. The rear end of the sub-frame can interfere with the protruding portion of the floor frame member to reliably generate a reaction force.

[0021]

Embodiments of the present invention will be described below in detail with reference to the drawings.

In FIGS. 1 to 6, reference numeral 1 denotes a dash panel for separating a vehicle room R from a power unit mounting room PR in front of the vehicle room R. The lower end of the inclined toe board 1b on the lower side thereof is substantially horizontal. It is bent and joined to the front end of the floor panel 2.

A front side member 3 as a skeletal member in the vehicle front-rear direction is provided on both left and right sides of the power unit mounting room PR. The front side member 3 is a front surface of a rising wall 1a of the dash panel 1. At the rear side, the extension part 5 is formed by extending from the toe board 1b to the lower surface thereof and extending in the front-rear direction toward the rear of the floor panel 2 to join.

Side sills 6 as frame members in the front-rear direction of the vehicle body are also joined and disposed at both left and right end portions of the floor panel 2, and the front end portion of the side sill 6 and the front end portion of the extension portion 5 of the front side member 3 are connected to each other. Are connected by the outriggers 7 to connect the frame members together.

The front ends of the left and right front side members 3, 3 are connected by a first cross member as a frame member in the vehicle width direction (not shown). A downwardly projecting mounting seat 8 is formed, and front ends on both sides in the vehicle width direction of a subframe 9 for mounting and supporting a power unit such as an engine unit or a motor unit (not shown) are fastened to the mounting seat 8 with bolts and nuts. It is fixed.

This sub-frame 9 is a front frame 9
f, the rear frame 9r and the side frames 9s on both sides are formed in a cross-girder shape, and the rear ends 9E on both sides in the vehicle width direction.
Specifically, the rear end of the side frame 9s is located on the lower surface side of the dash panel 1 as described later, that is, the toe board 1
b is fastened and fixed to the lower surface side.

The power unit mounting room PR
The reaction force generating members 11 and 12, which abut against each other by a displacement due to an input at the time of an offset collision of the vehicle to generate a reaction force,
Is provided.

In the present embodiment, a cross-shaped sub-frame 9 in which the rear ends 9E on both sides in the vehicle width direction are fastened and fixed to the lower surface of the dash panel 1 is used as one reaction force generating member 11, and the other reaction force is generated. The generating member 12 is located on the lower surface of the dash panel 1, specifically, the lower surface of the toe board 1b, close to the rear end 9E of the sub-frame 9, and offset from the rear end 9E inward in the vehicle width direction. It is composed of the floor frame members 13 arranged.

In this embodiment, the floor frame member 13
Extends from the toe board 1b to the floor panel 2 and extends in the longitudinal direction of the vehicle body in parallel with the adjacent extension portion 5 and has a rear end formed on the left and right side sills 6 on the upper surface of the floor panel 2. The position crossing the second cross member (cross member) 14 that is joined and arranged over the straddle is configured as the toe end portion. Of course, the position extends further rearward and crosses the rear seat cross member (not shown). It may be a toe.

The floor frame members 13 are formed at substantially the same downward projecting height as the extension portions 5, and the front ends of the floor frame members 13 and the extension portions 5 are formed.
A closed cross-section 15 is provided over the front end portion of the sub-frame 9, and rear ends 9E on both sides of the sub-frame 9 in the vehicle width direction are fastened and fixed to the lower surface of the closed cross-section 15.

Reference numeral 16 denotes a bracket constituting the closed cross-section portion 15. The bracket 16 comprises a bottom wall 17 and a bottom wall 17.
And a rear wall 19 rising from the rear end of the bottom wall 17.

A stiffener 20 is superposed on the upper surface (inner surface) of the bottom wall 17, one side of the bottom wall 17 is provided on the lower surface of the extension portion 5, and the other side is provided on the floor frame. The lower surface of the member 13 is overlapped and joined.

The front wall 18 is overlapped and joined to the side surface of the kick-up portion 4 which is a continuous portion of the extension portion 5 of the front side member 3 via a flange 18a on one side thereof, and the upper end portion of the dash panel 1 is joined. Rising wall 1a
The front end of the floor frame member 13 is overlapped and joined to the front wall 18 via the flange 13a to close the front end opening.

The rear wall 19 has its upper edge flange 19a joined to the floor panel 2 (including the lower horizontal portion of the toe board 1b).

The rear end 9E of the sub-frame 9 is fastened and fixed to the lower surface of the closed section 15 via bolts 21 provided on the bracket 16.

The bolt 21 penetrates through the bottom wall 17 of the bracket 16 and the stiffener 20, and is fixed to the stiffener 20 by joining a flange 21 a provided in the middle of the shaft portion.

A bolt support bracket 22 for penetrating and supporting the upper end of the bolt 21 is provided in the closed section 15.
Is arranged.

The bolt support bracket 22 has an upper wall 23 and a rear wall 24, and a flange 23 at the front end of the upper wall 23.
a is overlapped and joined to the front wall 18 of the bracket 16, one side flange 23 b is overlapped and joined to the side surface of the corresponding floor frame member 13, and the flange 24 a at the lower end of the rear wall 24 is joined to the bracket 16. And a flange 24b on one side is overlapped and joined to the side surface of the corresponding floor frame member 13, so that the closed cross section 15 is vertically separated from the inside of the closed cross section 15. The upper end of the bolt 21 is supported through the upper wall 23 of the bolt support bracket 22.

According to the structure of the above-described embodiment, when the vehicle collides with the vehicle in a frontal wrap state, the left and right front side members 3 are buckled and deformed in the front-rear direction, and the side frames 9s of the sub-frame 9 are bent downward. The buckling deformation of the front side member 3 and the downward bending deformation of the subframe 9 absorb the collision energy.

At the time of this full wrap collision, the rear end 9E of the side frame 9s and the front end of the floor frame member 13 are offset from each other in the vehicle width direction. Even if the rear frame 9s moves, the rear end 9E of the side frame 9s does not come into contact with the front end of the floor frame member 13, so that the reaction force does not become excessive in the latter half of the full-lap collision. The ideal energy absorption characteristics as shown in FIG. 9 can be obtained.

That is, in the diagram of FIG. 9, P1 indicates the peak value of the deformation load (reaction force) between the front side member 3 and the subframe 9 at the initial stage of the collision, and P2 indicates the V-shaped downward bending of the subframe 9. The lowering point of the reaction force at the time when the deformation progresses and the road surface interferes, and P3 indicates the peak value of the reaction force that has risen again after the subframe 9 has interfered with the road surface.

On the other hand, when the vehicle collides from the front with the vehicle in an offset state, the collision load is concentrated on one side of the front part of the vehicle body.
At this time, energy is absorbed by the buckling deformation of one front side member 3 and the downward bending deformation of one side frame 9s of the sub-frame 9.

Therefore, as shown by the line a in FIG. 10, the rising peak value P11 of the reaction force at the initial stage of the collision is smaller than that at the time of the full-lap collision.

At the time of the offset collision, for example, as shown in FIG. 7, the sub-frame 9 having substantially the center of the fastening portion at the rear end 9E of the side frame 9SL on one side and the side frame 9SR on the opposite side where the collision load F is concentrated. As a result, the rear end 9E of the side frame 9SL is displaced so as to wrap around the front end of the adjacent floor frame member 13 together with the crush deformation of the closed cross-section 15.

The reaction force decreases with the progression of the U-shaped downward bending deformation of the one side frame 9SL, and then the side frame 9SL interferes with the road surface (P12 of line a).
Point), the reaction force is increased again by the transmission of the input from the side frame 9SL to the closed section 15 and the floor frame member 13, but the rear end 9E of the side frame 9SL is moved to the floor frame member 13 as shown in FIG. Of the reaction force rises sharply at the point Px of the line a in FIG. 10, and the peak value of the reaction force in the latter half of the collision rises as shown at P13, thereby increasing the efficiency. In addition to absorbing energy, the rear end 9E of the sub-frame 9 and the floor frame member 13 abut against each other, so that the deformation of the dash panel 1 toward the passenger compartment R can be reduced.

The line b in FIG. 10 shows the energy absorption characteristics at the time of an offset collision when the floor frame member 13 is not provided. One side frame 9 s of the sub-frame 9 is bent and deformed in a U-shape to cause road surface interference. Then, since there is no reaction force generation means, after the reaction force decreases from point P12 in the same figure,
The reaction force gradually increases due to the transmission of the input to the dash panel 1, but the peak value of the reaction force is low, and the amount of deformation of the dash panel 1 toward the cabin R increases.

As described above, according to the present embodiment, at the time of an offset collision of the vehicle, the reaction force is generated by mutual displacement and contact between the rear end portion 9E of the sub-frame 9 and the floor frame member 13, which are reaction force generating members. As a result, the deformation of the front part of the vehicle compartment can be suppressed to a small extent, and ideal energy absorption characteristics can be obtained. The rear end 9E of the subframe 9 and the floor frame member 13 do not come into contact with each other at the time of a full lap collision, so that the reaction force in the latter half of the collision is reliably prevented. be able to.

As described above, one of the reaction force generating members 1
The sub-frame 9 is effectively used as 1 to obtain an advantage in terms of cost, and the other reaction force generating member 12 is configured as a floor frame member 13, so that the floor rigidity is increased and the vehicle frontal collision occurs. The deformation of the front part of the passenger compartment at the time can be further reduced.

Further, since the floor frame member 13 is arranged in the front-rear direction of the lower surface of the dash panel 1, that is, from the toe board 1 b to the floor panel 2, a power unit (not shown) at the time of a vehicle front collision is provided. The rearward movement of the vehicle compartment can be suppressed by the floor frame member 13 to enhance the effect of suppressing the deformation of the front part of the passenger compartment.

Further, since the rear end of the floor frame member 13 is disposed so as to intersect with the second cross member 14 joined to the floor panel 2, a collision input acting on the floor frame member 13 at the time of frontal collision of the vehicle. Can be efficiently transmitted to the cross member 14, the side sill 6, the extension portion 5 of the front side member 3 and the like, and the load can be dispersed, thereby further increasing the floor rigidity.

Further, the fastening and fixing portion of the rear end portion 9E of the sub-frame 9 is formed as a closed cross-sectional portion 15 provided over the extension portion 5 and the floor frame member 13. The strength and rigidity of the fixed portion at the end 9E are high, and the mounting support rigidity of a power unit such as an engine or a motor can be increased.

FIG. 11 shows a second embodiment of the present invention. In this embodiment, the front frame of the floor frame member 13 in the first embodiment is placed after the sub-frame 9 at the time of an offset collision. A projection 25 is provided which can interfere with the rear end 9E when the end 9E is rotated inward in the vehicle width direction.

According to the structure of the second embodiment, when the rear end 9E of the sub-frame 9 is rotationally displaced inward in the vehicle width direction by the offset collision of the vehicle as described above, the rear end 9E is The reaction force can be reliably generated by contacting the protruding portion 25 of the floor frame member 13.

FIG. 12 shows a third embodiment of the present invention. In this embodiment, a substantially L-shaped cross-section is formed below the toe board 1b of the dash panel 1 to form a triangular closed cross-section. Are connected to each other.

The dash cross member 26 is provided with extension portions 5, 5 of the left and right front side members 3, 3.
The front and rear ends of the dash cross member 26 are formed stepwise so that the left and right sides of the dash cross member 26 have the bottom wall 26a at substantially the same position as the downward projecting height of the extension portion 5, The side edge of the bottom wall 26 a is joined to the lower surface of the extension 5.

Further, the front end side surface of the floor frame member 13 is joined to the step side surface of the bottom wall 26a, and the distance between the extension portion 5 and the front end portion of the floor frame member 13 is substantially the same as in the first embodiment. It has a closed cross-section structure, and bolts 21 are protrudingly arranged on the lower surface side thereof so that the rear end 9E of the sub-frame 9 is fastened and fixed via the bolts 21.

Since the front end of the floor frame member 13 overlaps and joins the bottom wall 26a of the dash cross member 26 joined to the floor panel 2, the front end is different from that of the first embodiment. It has the same closed cross-sectional shape as the rear end side, and the front end is configured as a closed end.

Therefore, even with the structure of the third embodiment, the same effects as those of the first embodiment can be obtained, and the strength and rigidity of the front part of the vehicle compartment can be increased by the presence of the dash cross member 26. The effect of suppressing the deformation of the front part of the cabin at the time of a frontal collision can be further enhanced.

FIG. 13 shows a fourth embodiment of the present invention. In this embodiment, the rear end of the subframe 9 at the time of an offset collision is provided on the front side of the floor frame member 13 in the third embodiment. A protruding portion 25 is formed which is capable of interfering with the rear end portion 9E when the portion 9E is rotated inward in the vehicle width direction.

Therefore, according to the fourth embodiment, in addition to the effect of the third embodiment, the rear end portion 9E of the sub-frame 9 is rotated inward in the vehicle width direction due to the offset collision of the vehicle as described above. In this case, the rear end portion 9E abuts on the protruding portion 25 of the floor frame member 13 to reliably generate a reaction force.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a bottom surface side of a vehicle body front structure according to a first embodiment of the present invention.

FIG. 2 is a perspective view similar to FIG. 1, showing a state where a sub-frame is removed.

FIG. 3 is an exploded perspective view showing the bottom side of a fastening portion at the rear end of the subframe.

FIG. 4 is a bottom view showing the first embodiment of the present invention.

FIG. 5 is a sectional view taken along the line AA of FIG. 4;

FIG. 6 is a sectional view taken along the line BB of FIG. 4;

FIG. 7 is a bottom view similar to FIG. 4, showing a deformed state at the time of an offset collision;

FIG. 8 is a sectional view showing a deformed state at the time of an offset collision.

FIG. 9 is an energy absorption characteristic diagram at the time of a full lap collision.

FIG. 10 is an energy absorption characteristic diagram at the time of an offset collision.

FIG. 11 is a perspective view similar to FIG. 2, showing a second embodiment of the present invention.

FIG. 12 is a perspective view similar to FIG. 2, showing a third embodiment of the present invention.

FIG. 13 is a perspective view similar to FIG. 2, showing a fourth embodiment of the present invention.

[Description of Signs] R Vehicle Room PR Power Unit Mounting Room 1 Dash Panel 2 Floor Panel 3 Front Side Member 6 Side Sill 9 Subframe 9E Rear End 11,12 Reaction Force Generating Member 13 Floor Frame Member 14 Cross Member 15 Closed Section Part 25 Projection

Claims (7)

[Claims] A reaction force generating member is provided at a rear portion of a power unit mounting room separated from a front side of a vehicle room by a dash panel to generate a reaction force by mutually abutting upon displacement due to an input at the time of an offset collision of a vehicle. The front structure of the vehicle body. 2. The vehicle body front structure according to claim 1, wherein the reaction force generating members are arranged so as not to abut against each other when the vehicle is displaced by an input during a full lap collision of the vehicle. 3. A cross-shaped sub-frame in which rear ends of both sides in the vehicle width direction are fastened and fixed to a lower surface of a dash panel, and a reaction force generating member is provided near a rear end of the sub-frame on a lower surface of the dash panel. The vehicle body front structure according to claim 1 or 2, further comprising: a floor frame member arranged to be offset inward in the vehicle width direction from the rear end. 4. The vehicle body front structure according to claim 3, wherein the floor frame member is disposed extending in the vehicle front-rear direction from the lower front end portion of the dash panel to the floor panel. 5. A front side member disposed in the vehicle longitudinal direction outside the floor frame member in the vehicle width direction, and a closed cross section is provided across the floor frame member, and a sub-section is provided on a lower surface of the closed cross section. The vehicle body front structure according to claim 4, wherein a rear end of the frame is fastened and fixed. 6. The floor member according to claim 4, wherein a rear end portion of the floor frame member is arranged to cross the cross member joined and arranged on the floor panel across the side sills on both sides in the vehicle width direction. Body front structure. 7. The floor frame member according to claim 5, wherein a protrusion is provided on the front side of the floor frame member, the protrusion being capable of interfering with the rearward displacement of the rear end of the sub-frame in the vehicle width direction. Body front structure.