JP2007290426A - Structure of front part of car body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide the structure of the front part of a car body, which efficiently transfers a load in a head-on collision while suppressing a bending load applied to a dash panel in the head-on collision of a vehicle. <P>SOLUTION: Front pillars 34 are tilted such that their front end portions approach toward the inside of the width of the vehicle (the direction of an arrow IN) with the distance forward of the vehicle (the direction of an arrow FR). Further, wall portions 36A in tunnel portions 36 are tilted such that their front end portions approach the outside of the width of the vehicle (the opposite direction of the arrow IN) with the distance forward of the vehicle (the direction of the arrow FR). In addition, rear end portions of front side members 20 are divided into fork shapes to rearward of the vehicle, and are smoothly connected to the front pillar 34 sides and the tunnel portion 36 sides. Therefore, the load in the head-on collision input from a front bumper reinforcement 26 to the front side members 20 is transferred to the front pillar 34 sides and the tunnel portion 36 sides along smooth passages almost without being transferred to the dash panel 14. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a vehicle body front portion structure that includes a front side member that extends substantially in the vehicle longitudinal direction on both sides of a vehicle body front portion.

  In the front structure of the vehicle body, the front side member is connected to the front pillar and the tunnel via the dash cross member in order to suppress the bending load on the dash panel at the time of the front collision of the vehicle. The part may have a truss structure (see, for example, Patent Document 1).

However, in this conventional structure, the front impact load acts in the direction separating the front pillar and the tunnel, and the load cannot be transmitted efficiently.
JP 2003-212157 A

  In view of the above fact, an object of the present invention is to provide a vehicle body front structure that can efficiently transmit a front collision load while suppressing a bending load to the dash panel during a vehicle front collision.

  The vehicle body front structure of the present invention described in claim 1 is provided on both sides of the dash panel, and a front pillar whose front end portion is inclined inward in the vehicle width direction toward the front of the vehicle, and the dash panel at the rear of the vehicle. A tunnel portion that is provided at a substantially central portion in the vehicle width direction, and whose front end portion is inclined outward in the vehicle width direction toward the front of the vehicle and coupled to the dash panel, and on both sides of the front portion of the vehicle body in a substantially vehicle longitudinal direction. A front side member extending and having a rear end portion bifurcated toward the rear of the vehicle and smoothly connected to the front pillar side and the tunnel portion side.

  According to the vehicle body front portion structure of the present invention described in claim 1, the front end portion side of the front pillar is inclined inward in the vehicle width direction toward the front of the vehicle, and the front end portion side of the tunnel portion is directed toward the vehicle front. The rear side of the front side member is bifurcated toward the rear of the vehicle and is gently connected to the front pillar side and the tunnel side. The front impact load input to the front pillar side and the tunnel portion side is transmitted through a gentle path with almost no transmission to the dash panel.

  The vehicle body front part structure according to a second aspect of the present invention is the vehicle body front part structure according to the first aspect, wherein the front side member has one branched rear end at the front end side of the front pillar in the vehicle width direction. And the other branched rear end portion is joined to a second inclined surface which is an inner side surface in the vehicle width direction on the front end portion side of the tunnel portion.

  According to the vehicle body front part structure of the present invention as set forth in claim 2, the front side member is joined to the first inclined surface, which is the outer side surface in the vehicle width direction on the front end side of the front pillar. In addition, since the rear end portion of the other branched portion is joined to the second inclined surface which is the inner surface in the vehicle width direction on the front end portion side of the tunnel portion, the front collision load input to the front side member from the front side of the vehicle Is transmitted to the front pillar and the tunnel portion through a gentle route.

  According to a third aspect of the vehicle body front structure of the present invention, the front pillar and the tunnel portion are made of carbon fiber reinforced plastic in the configuration of the first or second aspect, and at least one of the front pillars. The fiber direction of the portion is equal to the direction in which the front pillar is inclined in a plan view, and at least a part of the fiber direction in the tunnel portion is equal to the direction in which the tunnel portion is inclined in a plan view.

  According to the vehicle body front part structure of the present invention described in claim 3, at least a part of the fiber direction in the front pillar is equal to the direction in which the front pillar inclines in a plan view, and at least a part of the fiber direction in the tunnel part is flat. Since it is equal to the direction in which the tunnel portion inclines, the support force of the front pillar and tunnel portion against the front impact load is increased (support rigidity is increased), and the front pillar and tunnel portion from the front side member at the time of vehicle front impact When the load is transmitted to the front pillar, the front pillar and the tunnel portion can reliably support the load.

  As described above, according to the vehicle body front structure according to claim 1 of the present invention, the front collision load is applied to the front pillar side and the tunnel side while suppressing the bending load to the dash panel at the time of the vehicle front collision. It has an excellent effect of being able to transmit efficiently.

  According to the vehicle body front part structure of the second aspect, there is an excellent effect that the front collision load can be transmitted from the front side member to the front pillar and the tunnel part through a gentle path.

  According to the vehicle body front structure according to the third aspect, the front pillar and the tunnel portion can reliably support the front collision load.

[First Embodiment]
A first embodiment of a vehicle body front structure according to the present invention will be described with reference to the drawings. In the figure, arrow UP indicates the vehicle upward direction, arrow FR indicates the vehicle front direction, and arrow IN indicates the vehicle width direction inner side.

  As shown in FIG. 1, the engine room 10 and the cabin 12 (vehicle compartment) are separated by a dash panel 14. A pair of left and right front side members 20 extend substantially in the vehicle front-rear direction on both sides of the vehicle body front portion 18 (details will be described later). As shown in FIG. 2, the front end portions of the pair of left and right front side members 20 are connected to each other by a front bumper reinforcement 26 arranged with the vehicle width direction as a longitudinal direction. The front bumper reinforcement 26 is a long, high-strength member that constitutes a part of the front bumper, and is disposed on the rear side of a front bumper cover (not shown). A front cross member 27 is bridged between the pair of front side members 20 at the rear of the front bumper reinforcement 26.

  The front side member 20 is provided with a spring support portion 22S slightly behind the front cross member 27. The spring support portion 22S has an upper end of a shock absorber 29 for buffering road surface input from the tire 28. The parts are connected and supported. The lower end of the shock absorber 29 is connected to and supported by a suspension arm 30 that is swingably supported by a suspension member (not shown).

  A lower end portion of the dash panel 14 shown in FIG. 1 is coupled to the vehicle body floor 16, and rockers 32 are disposed on both sides of the vehicle body floor 16 in the vehicle width direction. In addition, a pair of left and right front pillars 34 extending from the rocker 32 in the vehicle vertical direction is provided upright on both sides of the dash panel 14 in the vehicle width direction. As shown in FIG. 2, the front pillar 34 is inclined inwardly in the vehicle width direction (arrow IN direction) toward the vehicle front (arrow FR direction) on the front end side. Here, the front end portion side of the front pillar 34 has a gentle substantially arc shape with a large curvature radius without a bent portion in plan view, and is a vehicle width direction outer side surface on the front end portion side of the front pillar 34. The front pillar outer surface 34A as one inclined surface is a gently inclined curved surface inclined inward in the vehicle width direction toward the front of the vehicle.

  At the rear of the dash panel 14 shown in FIG. 1, there is a tunnel portion 36 extending in the vehicle front-rear direction at a substantially central portion in the vehicle width direction, that is, at a substantially central portion of the vehicle body floor 16 constituting the bottom portion of the cabin 12. Is provided. The tunnel portion 36 has a substantially U-shaped cross-sectional shape when viewed from the front of the vehicle with the opening facing the lower side of the vehicle body, and includes a pair of wall portions 36A facing each other. As shown in FIG. 2, the wall portion 36 </ b> A in the tunnel portion 36 is inclined to the dash panel 14 with the front end side inclined toward the vehicle front (arrow FR direction) outward in the vehicle width direction (opposite direction of the arrow IN direction). Are combined. Here, the front end portion side of the tunnel portion 36 has a gentle substantially circular arc shape with no bending portion and a large curvature radius in plan view. A tunnel inner wall surface 36B as a second inclined surface, which is an inner side surface in the vehicle width direction on the front end side of the tunnel portion 36, has a gently curved surface that is inclined outward in the vehicle width direction toward the front of the vehicle.

  The dash panel 14, the front pillar 34, the tunnel portion 36, and the like that separate the inside and outside of the cabin 12 are made of carbon fiber reinforced plastic (CFRP). ) Is equal to the direction in which the front pillar 34 inclines in plan view, and at least a part (in the present embodiment, most) of the fiber direction in the wall portion 36A of the tunnel portion 36 is the wall in the tunnel portion 36 in plan view. It is equal to the direction in which the portion 36A is inclined.

  The front side member 20 has a front side member front portion 21 connected to the front bumper reinforcement 26 formed of an aluminum extruded material. The front side member 20 is provided behind the front side member front portion 21 and a front cross member 27 is passed over. The front side member intermediate portion 22 including the spring support portion 22S is formed of an aluminum casting, and the front side member rear portion 23 provided on the vehicle rear side of the front side member intermediate portion 22 is formed of an aluminum extruded material.

  With respect to the front side member front portion 21 and the front side member intermediate portion 22, the above-described front pillar 34 is disposed on the vehicle width direction outer side as viewed from the front of the vehicle. It is arranged on the inner side in the width direction.

  The front side member rear portion 23 which is the rear end portion side of the front side member 20 branches into a bifurcated shape toward the rear of the vehicle, and the vehicle width direction central portion 23A of the front side member rear portion 23 extends from the dash panel 14. In addition to being separated from each other, it is gently connected to the front pillar 34 side and the tunnel portion 36 side (so that the load transmission path becomes gentle).

  The first branched portion 24 as one branched portion in the front side member rear portion 23 includes a first contact portion 24A that contacts the front surface portion 34F of the front pillar 34, and is joined to the front pillar outer surface 34A of the front pillar 34. The first joint portion 24B is provided as a rear end portion. A bolt insertion hole (not shown) is formed in the first joint portion 24B, and a collar (not shown) is disposed in a penetrating manner at a portion of the front pillar 34 corresponding to the bolt insertion hole. The bolt 40 is inserted from the outer side in the vehicle width direction of the first joint portion 24B in a state where the surface 24B and the front pillar outer surface 34A are in surface contact, and the nut 41 is screwed into the tip end portion of the bolt 40 from the cabin 12 side. The first joint portion 24 </ b> B is attached to the front pillar 34 by bolt fastening. Thereby, the 1st branch part 24 and the front pillar 34 are in the state where the extension direction in planar view was smoothly continued, and is made into the shape which does not bend the connection part front and back.

  The second branched portion 25 as the other branched portion of the front side member rear portion 23 includes a second contact portion 25A that contacts the front surface portion 36F of the tunnel portion 36, and is joined to the tunnel inner wall surface 36B of the tunnel portion 36. A second joint portion 25B is provided as a rear end portion. A bolt insertion hole (not shown) is formed in the second joint portion 25B, and a collar (not shown) is disposed in a penetrating manner in a portion of the tunnel portion 36 (wall portion 36A) corresponding to the bolt insertion hole. The bolt 42 is inserted from the inner side in the vehicle width direction of the second joint portion 25B in a state where the second joint portion 25B and the tunnel inner wall surface 36B are in surface contact, and the nut 43 is screwed into the tip end portion of the bolt 42 from the cabin 12 side. As a result, the second joint portion 25B is attached to the wall portion 36A of the tunnel portion 36. Thereby, the 2nd branch part 25 and the tunnel part 36 are in the state where the extension direction in planar view was continued smoothly, and is made into the shape which does not bend the connection part front and back.

  The first joint portion 24B may be attached to the front pillar 34 and the second joint portion 25B may be attached to the tunnel portion 36 by only bolt fastening as described above. Bolt fastening may be performed later.

(Action / Effect)
Next, the operation and effect of the above embodiment will be described.

  At the time of a frontal collision of the vehicle, the collision load is input to the front bumper reinforcement 26 from the front side of the vehicle and transmitted to the front side member 20. The front end side of the front pillar 34 is inclined inward in the vehicle width direction (arrow IN direction) toward the front of the vehicle (arrow FR direction), and the front end side of the wall portion 36A in the tunnel portion 36 is forward of the vehicle (arrow FR direction). It is inclined outward in the vehicle width direction (opposite direction of the arrow IN direction), and the rear end portion side of the front side member 20 branches into a bifurcated shape toward the rear of the vehicle toward the front pillar 34 side and the tunnel portion 36 side. Since it is smoothly connected, the front collision load input from the front bumper reinforcement 26 to the front side member 20 is hardly transmitted to the dash panel 14, and the front pillar 34 side and the tunnel portion 36 are smoothly routed through a gentle path. To the side. Note that the load transmitted to the front pillar 34 side is transmitted to the rocker 32.

  Here, in the present embodiment, the front side member 20 includes the first joint portion 24B of the first branch portion 24 joined to the front pillar outer surface 34A of the front pillar 34, and the second joint of the second branch portion 25. Since the portion 25B is joined to the tunnel inner wall surface 36B of the tunnel portion 36, the front collision load input to the front side member 20 is directly transmitted to the front pillar 34 and the tunnel portion 36 through a gentle path.

  Thereby, the front collision load can be efficiently transmitted to the front pillar 34 side and the tunnel part 36 side while suppressing the bending load to the dash panel 14 at the time of the vehicle front collision. In this way, by suppressing the bending load on the dash panel 14, it becomes possible to set the bending strength of the dash panel 14 to be lower than that in the prior art, so the thickness and cross-sectional area of the dash panel 14 are reduced. It can also be reduced in weight.

  Further, most of the fiber directions in the front pillar 34 are equal to the direction in which the front pillar 34 is inclined in a plan view, and most of the fiber directions in the tunnel portion 36 are equal to the direction in which the tunnel portion 36 is inclined in a plan view. Therefore, these fiber directions become equal to the load directions (arrow A direction and arrow B direction) at these parts at the time of vehicle front collision. For this reason, the support force of the front pillar 34 and the tunnel portion 36 against the front impact load is increased (support rigidity is increased), and the load is transmitted from the front side member 20 to the front pillar 34 and the tunnel portion 36 at the time of the vehicle front impact. Thus, the front pillar 34 and the tunnel portion 36 can reliably support the load.

[Second Embodiment]
Next, a second embodiment of the vehicle body front structure will be described with reference to FIG. The second embodiment is characterized in that the front side member 20 is gently connected to the front pillar 34 and the tunnel portion 36 via the dash cross member 44 (so that the load transmission path becomes gentle). Since other configurations are substantially the same as those of the first embodiment, substantially the same components are denoted by the same reference numerals and description thereof is omitted.

  As shown in FIG. 3, the dash cross member 44 extends along the vehicle width direction, and an intermediate portion in the vehicle width direction has a front surface portion 34F of the front pillar 34, a front surface portion 14F of the dash panel 14, and The tunnel portion 36 is bonded to the front surface portion 36F. Both sides of the dash cross member 44 in the vehicle width direction are bent so as to spread toward the rear of the vehicle, and are bonded to the front pillar outer surface 34A and the tunnel inner wall surface 36B. In addition, you may apply bolt fastening to each of these joining similarly to 1st Embodiment.

  The first abutment portion 24A and the first joint portion 24B in the first branch portion 24 of the front side member 20 are bonded to the outer side portion (bent portion) of the dash cross member 44 in the vehicle width direction. The second abutment portion 25A and the second joint portion 25B in the second branch portion 25 are bonded to the inner side portion (bent portion) of the dash cross member 44 in the vehicle width direction. Accordingly, the first contact portion 24A is disposed in front of the front surface portion 34F of the front pillar 34 with the dash cross member 44 interposed therebetween, and the second contact portion 25A is disposed on the front surface portion of the tunnel portion 36 with the dash cross member 44 interposed therebetween. It is arranged in front of 36F. In addition, the vehicle width direction center portion 23 </ b> A at the rear end of the front side member rear portion 23 is separated from the dash cross member 44. Note that bolt fastening may be applied to the joining of the first branch portion 24 and the dash cross member 44 and the joining of the second branch portion 25 and the dash cross member 44.

  Also in the second embodiment described above, the front collision load is applied to the front pillar 34 side and the tunnel portion 36 side while suppressing the bending load to the dash panel 14 at the time of the vehicle front collision by the same action as the first embodiment. It can be transmitted efficiently. Further, by providing the dash cross member 44, rigidity against torsion can be improved.

[Supplementary explanation of the embodiment]
In the above embodiment, the dash panel 14, the front pillar 34, the tunnel portion 36 and the like that separate the inside and outside of the cabin 12 are made of carbon fiber reinforced plastic (CFRP), but the inside and outside of the cabin 12 are separated. The dash panel 14, the front pillar 34, the tunnel portion 36, and the like may be made of other materials such as steel.

1 is a perspective view showing a vehicle body front part structure according to a first embodiment of the present invention. 1 is a horizontal sectional view showing a vehicle body front part structure according to a first embodiment of the present invention. It is a horizontal sectional view showing the body front part structure concerning a 2nd embodiment of the present invention.

Explanation of symbols

14 Dash panel 18 Car body front part 20 Front side member 24 1st branch part (one branched)
24B 1st joint part (branched one rear end part)
25 Second branch (the other branch)
25B second joint (branched other rear end)
34 Front pillar 34A Front pillar outer surface (first inclined surface)
36 Tunnel part 36B Tunnel inner wall surface (second inclined surface)
FR Vehicle front IN Vehicle width direction inside

Claims (3)

A front pillar that is provided on both sides of the dash panel, and whose front end side is inclined inward in the vehicle width direction toward the front of the vehicle;
A tunnel portion provided at a substantially central portion in the vehicle width direction of the dash panel at the rear of the vehicle, the front end portion being inclined outward in the vehicle width direction toward the vehicle front, and coupled to the dash panel;
A front side member extending substantially in the vehicle front-rear direction on both sides of the front part of the vehicle body, the rear end side branching into a bifurcated shape toward the rear of the vehicle, and smoothly connected to the front pillar side and the tunnel part side; ,
The vehicle body front part structure characterized by having.   In the front side member, one branched rear end is joined to a first inclined surface which is an outer surface in the vehicle width direction on the front end side of the front pillar, and the other branched rear end is the tunnel portion. The vehicle body front part structure according to claim 1, wherein the vehicle body front part structure is joined to a second inclined surface which is an inner side surface in the vehicle width direction on the front end side of the vehicle.   The front pillar and the tunnel part are made of carbon fiber reinforced plastic, and at least a part of the fiber direction in the front pillar is equal to a direction in which the front pillar inclines in a plan view, and at least a part of the fiber direction in the tunnel part. The vehicle body front part structure according to claim 1 or 2, wherein is equal to a direction in which the tunnel portion inclines in a plan view.

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