JP2006232013A - Vehicle front structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve impact absorption of a vehicle.
SOLUTION: A rear end portion is connected to a front pillar extending in the vehicle vertical direction, and a pair of left and right apron upper members extending in the vehicle longitudinal direction, and a substantially rectangular shape straddling between the pair of left and right apron upper members. And a pair of left and right apron upper members having grip portions for gripping both end portions of the hood extending in the vehicle front-rear direction in the apron upper member. Moreover, it is preferable that a holding | grip part is a pair of rail part extended in a vehicle front-back direction, and the both ends of a hood are inserted by a pair of rail part, and it can move relatively to a vehicle front-back direction with respect to a rail part. .
[Selection] Figure 1

Description

  The present invention relates to a vehicle front structure with improved shock absorption.

2. Description of the Related Art Conventionally, there is known a vehicle body front structure in which a front side member and an apron upper member are coupled with a straight panel to prevent bending deformation of the front side member at the time of a collision (see, for example, Patent Document 1).
JP 7-149261 A

  In the conventional vehicle body front structure described above, an apron upper member is disposed at the upper part of the vehicle as a member that receives impact load from the front. In the event of a collision, the apron upper member transmits the impact load input to the upper part of the engine compartment to the cabin via the A pillar and the belt line.

  Further, when the apron upper member is formed long in the vehicle front-rear direction so as to receive a load from the initial stage of the collision, the apron upper member is easily bent and deformed. Due to this bending deformation, the apron upper member cannot sufficiently transmit the load to the cabin, so that the impact load may not be sufficiently absorbed. On the other hand, even when the apron upper member is formed short in the longitudinal direction of the vehicle, the apron upper member receives an impact load only in the latter half of the collision, so that the impact load may not be sufficiently absorbed.

  The present invention has been made to solve such problems, and its main object is to improve the impact absorption of a vehicle.

  In one aspect of the present invention for achieving the above object, a pair of left and right apron upper members whose rear end portions are connected to a front pillar extending in the vehicle vertical direction and extending in the vehicle longitudinal direction, A substantially rectangular hood straddled between the apron upper members, wherein the pair of left and right apron upper members extend in the vehicle front-rear direction within the apron upper members. A vehicle front portion structure having a grip portion for gripping both ends of the vehicle.

  According to this aspect, the grip portion of the apron upper member grips both end sides of the hood extending in the vehicle front-rear direction in the apron upper member. Thus, both ends of the hood extending in the vehicle front-rear direction in the apron upper member can receive a load from the front of the vehicle. Therefore, the apron upper member is supported by both ends of the hood, and a high buckling load can be ensured with respect to the load from the vehicle front-rear direction. In addition, it is possible to secure a sufficient length of the apron upper member in the vehicle front-rear direction, and it is possible to improve the impact absorption of the apron upper member. Furthermore, by ensuring a sufficient length of the apron upper member, for example, a collision load at the time of a collision can be transmitted to the vehicle rear member via the apron upper member from the initial stage. Therefore, the impact load of the vehicle is improved because the collision load can be absorbed at an early stage. In addition, since the both ends of the said hood are hold | gripped by the said holding part of the said apron upper member, the buckling load of the said hood can be raised. Thereby, the absorbability of the impact load by the said hood can be improved.

  In this aspect, the gripping portion may be configured to support the load of the hood in the apron upper member and limit the movement of the hood. For example, the gripping portion of the hood may be welded, bolted, bonded, or the like. It is good also as a structure which couple | bonds both ends and the inside of the said apron upper member.

  Further, in this aspect, the grip portion is a pair of rail portions extending in the vehicle front-rear direction, and both end sides of the hood are inserted into the pair of rail portions, and the vehicle front-rear direction with respect to the rail portion It is preferable that the relative movement is possible. As a result, the hood can be moved relative to the front of the vehicle to open the hood, and work can be performed on the engine compartment or the like inside the hood.

  Furthermore, in this one aspect, it is preferable that the hood is formed with a skeleton portion extending in the vehicle width direction. The skeleton portion suppresses deformation of the apron upper member in the vehicle width direction. Therefore, a collision load in the vehicle longitudinal direction can be more reliably absorbed by the apron upper member.

  In addition, in this one aspect | mode, it is further provided with a pair of fenders arrange | positioned by the vehicle side, and it is preferable that the said hood and the said fender are formed integrally continuously. Thereby, the so-called parting part between the hood and the fender, which exists in the conventional structure and is formed harder than other parts, can be eliminated. Therefore, it is possible to improve the impact absorbability of the boundary region between the hood and the fender. That is, when an obstacle or the like collides with the boundary region between the hood and the fender, the impact given to the obstacle or the like can be reduced. Further, by integrally forming the hood and the fender, it is possible to eliminate the design restriction due to the parting part existing in the conventional structure, and the degree of freedom of design is expanded.

  In this aspect, it is preferable that an inner panel joined to the inner surface of the hood is further provided, and a joint portion between the hood and the inner panel is not on an extension of the apron upper member in the vehicle vertical direction. Thereby, the impact load from above the vehicle to the hood can be absorbed by the bending deformation of the inner panel. Therefore, the impact load when an obstacle or the like collides with the hood from above the vehicle can be absorbed by the bending deformation of the inner panel, and the impact on the obstacle or the like can be reduced.

  According to the present invention, it is possible to improve the shock absorption of the vehicle.

Hereinafter, the best mode for carrying out the present invention will be described with reference to the accompanying drawings. The basic concept of the vehicle front structure, the main hardware configuration, and the like are known to those skilled in the art, and thus detailed description thereof is omitted.
(First embodiment)
FIG. 1 is a perspective view showing a vehicle front structure according to the first embodiment of the present invention, and is a schematic view showing a state in which a hood is opened. FIG. 2A is a cross-sectional view when the portion X shown in FIG. 1 is cut in the vehicle vertical direction, and shows a state where the hood is closed. Further, FIG. 2B is a cross-sectional view of the hood shown in FIG. 1 cut along a straight line AA ′ and shows a skeleton portion.

  In the vehicle front structure 1 according to the present embodiment, a pair of left and right apron upper members 3 extend in the vehicle front-rear direction in front of and above the vehicle. The rear end 3a of each apron upper member 3 is connected to the upper end of the front pillar lower by welding or the like. A pair of front side members 5 extending in the vehicle front-rear direction are disposed below the pair of apron upper members 3. A rear end portion of each front side member 5 is connected to a dash panel that defines an engine room and a vehicle compartment. The front end of each front side member 5 is connected to a front bumper reinforcement extending in the vehicle width direction. The apron upper member 3 and the front side member 5 are disposed substantially in parallel, and are connected via a panel member or the like.

  A radiator support 7 extending in the vehicle width direction extends between the front end portions of the pair of front side members 3. The radiator support 7 is formed in a substantially “day” shape when viewed from the front, and includes a radiator support upper 7a and a radiator support lower disposed in parallel vertically, and a vertical column 7b that connects the two in the vehicle vertical direction. Consists of. Further, an end portion of a radiator support upper 7a extending in the vehicle width direction is connected to the front end portion of each apron upper member 3 by welding or the like.

  Each apron upper member 3 has an outer rail portion 3b extending in the vehicle front-rear direction and having a substantially U-shaped cross section. The front end portion of the outer rail portion 3b is connected to the end portion of the radiator support upper 7a, and the rear end portion is connected to the upper end portion of the front pillar lower.

  A substantially rectangular hood 9 that can be opened and closed is provided between the pair of apron upper members 3. The hood 9 includes a hood outer 9a that forms an outer plate, and a hood inner 9b that is a skeleton of the hood outer 9a. The hood inner 9b has four skeleton portions 9c extending in the vehicle width direction and projecting toward the inside of the vehicle and substantially parallel to each other, and the skeleton portion 9c is joined to the inner surface of the hood outer 9a. Side walls 9d extending downward in the vehicle are integrally formed at both ends of the skeleton 9c. Inner rail portions 9e having a substantially rectangular cross section are formed at the ends of the side walls 9d. Each side wall 9d is formed with three openings for the purpose of weight reduction, but the number of openings to be formed may be arbitrary. Moreover, although the four skeleton parts 9c are joined to the inner surface of the hood outer 9a, the number of the skeleton parts 9c to be joined may be arbitrary.

  The inner rail portion 9e of the hood 9 is inserted into the outer rail portion 3b of the apron upper member 3, and the inner rail portion 9e is gripped by the outer rail portion 3b so as to be relatively movable (slidable) in the vehicle front-rear direction. In an open state in which the hood 9 slides forward of the vehicle, for example, maintenance of an engine disposed in the hood 9 is performed. On the other hand, in the closed state in which the hood 9 slides rearward of the vehicle and is locked by a lock mechanism 11 to be described later, the vehicle travels or the like. Normally, the hood 9 is placed in a closed state.

  Between the outer rail portion 3b and the inner rail portion 9e, an extended rail portion 9f extending in the vehicle front-rear direction and having a substantially rectangular cross section is slidably interposed. The extension rail portion 9f increases the rigidity of the inner rail portion 9e in a state where the hood 9 slides forward of the vehicle, and prevents the inner rail portion 9e from being bent due to its own weight. A lock mechanism 11 that locks the movement of the hood 9 toward the front of the vehicle when the hood 9 is closed is disposed at the front end of each inner rail portion 9e. The lock mechanism 11 is disposed at the front end portion of each inner rail portion 9e, but may be disposed at the rear end portion of each inner rail portion 9e, and is disposed at the center portion of the front edge of the hood 9. (FIG. 4). Further, the lock mechanism 11 is configured to be unlocked by pressing a protruding button.

  Next, the principle of absorbing the impact load in the vehicle front structure 1 will be described.

  FIG. 3A is a cross-sectional view when the apron upper member is cut in the vehicle vertical direction, and is a view showing a buckling load of the apron upper member. FIG. 3B is a view showing the buckling length of the apron upper member.

  As shown in FIG. 3A, for example, when an obstacle collides with the front part of the vehicle, the impact load is applied to the pair of apron upper members 3 and the pair of front side members 5 via the radiator support 7 and bumper reinforcement. F is input. The apron upper member 3 receives a compressive load between the front end portion and the rear end portion of the apron upper member 3 due to the impact load F and buckles. At the time of buckling, the buckling length of the apron upper member 3 is shortened by the inner rail portion 9e of the hood 9 held by the outer rail portion 3b of the apron upper member 3, and the buckling load of the apron upper member 3 is reduced. To increase. Specifically, the inner rail portion 9e and the outer rail portion 3b are supported by the skeleton portion 9c and the side wall 9d, and the apron upper member 3 is supported, thereby shortening the buckling length of the apron upper member 3 and buckling. The load can be increased.

  The buckling load is generally calculated by the following equation (1) (Euler equation).

P _E = (π ² × E × I) / I _r ² (1)
In the above formula (1), P _E represents the buckling load, I _r shows the buckling length. As can be seen from the above equation (1), the buckling load P _E is inversely proportional to the square of the buckling length I _r. That is, by reducing the buckling length I _r, it is possible to greatly increase the buckling load P _E.

Inner rail section 9e as in this embodiment is supported by the side wall 9d, if buckling length I _r, for example about I _{r /} 4, (1) the buckling load than equation about P _E × 16 next About 16 times (FIG. 3B).

  Further, the relationship between the absorbed energy E of the member, the load F applied to the member, and the stroke S of the member at the time of absorbing the load is expressed by the following equation (2).

E = F × S (2)
Since the absorbed energy E is proportional to the load F and the stroke S from the above equation (2), the absorbed energy E of the apron upper member 3 is increased by extending the apron upper member 3 forward and increasing the stroke S. be able to.

  That is, the apron upper member 3 is extended from the radiator support 7 as in this embodiment, and a sufficient length is secured, so that the impact energy absorbability of the apron upper member 3 can be improved. Moreover, since sufficient buckling load can be secured as described above while ensuring a sufficient length of the apron upper member 3, an impact load is transmitted to the cabin at an early stage via the apron upper member 3 and the belt line, The impact of the cabin can be suppressed early. Therefore, the comfort of the vehicle is improved. Further, since both ends of the hood 9 are gripped by the apron upper member 3 via the inner rail portion 9e and the outer rail portion 3b, the buckling load of the hood 9 can be increased. Thereby, the absorbability of the impact load by the hood 9 is improved.

Since the hood 9 is slidably attached to the front of the vehicle, the workability of the engine compartment is maintained. Moreover, in the said 1st Embodiment, although the frame | skeleton part 9c is extended in the vehicle width direction, you may extend radially from the center part of the front edge of the hood 9 (FIG. 4).
(Second Embodiment)
FIG. 5A is a perspective view showing a vehicle front structure according to the second embodiment of the present invention. FIG. 5B is a cross-sectional view when the Y portion shown in FIG. 5A is cut in the vehicle vertical direction, and shows a state where the hood is closed.

  As shown in FIG. 5, in the vehicle front structure 11 according to the second embodiment, a hood 19 and a fender 15 are formed continuously and integrally. That is, the fender 15 extends continuously and integrally from both ends of the hood 19 to the vehicle lower side. Further, in a state where the hood 19 is closed, a portion corresponding to the tire house in the fender 15 is cut out in an arc shape. Further, a front portion 19a extends from the front end of the hood 19 to the vehicle lower side, and a front grille, a headlight opening and the like are formed in the front portion 19a.

  An inner rail portion 19e is connected to the hood 19 and the fender 15 via a hood inner portion 19b by welding or the like, and the inner rail portion 19e is gripped by the outer rail portion 13b of the apron upper member 13 via the extension rail portion 19f. Yes. Further, the hood inner portion 19 b extends from the inner rail portion 19 e to the vehicle outer side, and a hood inner end 19 a whose end is connected to the fender 15 and a skeleton that extends in the vehicle width direction and is joined to the inner surface of the hood 19. The portion 9c and the second hood inner 19d that has one end connected to the skeleton portion 9c and the other end abutting against the outer rail portion 13b.

  Other configurations are substantially the same as those of the first embodiment shown in FIGS.

  In FIG. 5, the same parts as those of the first embodiment shown in FIGS. 1 to 4 are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the vehicle front part structure 11 shown in FIG. 5, the so-called parting part between the hood and the fender, which is present in the conventional structure and formed harder than the other parts, is formed by continuously and integrally forming the hood 19 and the fender 15. Can be eliminated. Thereby, the shock absorption property of the boundary region between the hood 19 and the fender 15 can be improved. Therefore, when an obstacle or the like collides with the boundary region between the hood 19 and the fender 15, the impact given to the obstacle or the like can be reduced. Further, by forming the hood 19 and the fender 15 integrally, the design restriction due to the parting part existing in the conventional structure can be eliminated, and the degree of freedom of design is expanded.

  Further, since the connecting portion between the skeleton portion 9c and the second hood inner 19d is not on the apron upper member 13 (the second hood inner 19d is tilted toward the inside of the vehicle), the impact load on the hood 19 from above the vehicle. Can be efficiently absorbed by the bending deformation of the second hood inner 19d. Thereby, when an obstacle or the like collides with the hood 19 from above the vehicle, the impact load is efficiently absorbed by the bending deformation of the second hood inner 19d, and the impact on the obstacle or the like can be reduced.

  The best mode for carrying out the present invention has been described above with reference to the embodiments. However, the present invention is not limited to these embodiments, and is described above without departing from the gist of the present invention. Various modifications and substitutions can be made to the embodiments.

  For example, in the first and second embodiments, the inner rail portions 9e and 19e of the hoods 9 and 19 are inserted into the outer rail portions 3b and 13b of the apron upper members 3 and 13, so that the hoods 9 and 19 are inserted. Although an example in which both end portions of the hood 9 are gripped is shown, any rail structure is applicable as long as both end portions of the hoods 9 and 19 are gripped.

  The present invention can be used for a vehicle front structure. The appearance, weight, size, running performance, etc. of the vehicle to be mounted are not limited.

It is a perspective view showing the vehicle front part structure concerning a 1st embodiment of the present invention, and is a schematic diagram showing the state where the hood was opened. (A) It is sectional drawing at the time of cut | disconnecting X part shown in FIG. 1 to a vehicle up-down direction, and is a figure which shows the state by which the hood was closed. (B) It is sectional drawing at the time of cut | disconnecting the hood shown in FIG. 1 by the straight line AA ', and is a figure which shows a frame | skeleton part. (A) It is sectional drawing at the time of cut | disconnecting an apron upper member to a vehicle up-down direction, and is a figure which shows the buckling load of an apron upper member. (B) It is a figure which shows the buckling length of the apron upper member. It is a figure which shows the state which the skeleton part extended radially from the food | hood front edge center part. (A) It is a perspective view which shows the vehicle front part structure which concerns on the 2nd Embodiment of this invention. (B) It is sectional drawing at the time of cut | disconnecting the Y part shown to Fig.5 (a) to a vehicle up-down direction, and is a figure which shows the state which closed the hood.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vehicle front part structure 3 Apron upper member 3b Outer rail part 5 Front side member 7 Radiator support 9 Hood 9b Hood inner 9c Frame | skeleton part 9d Side wall 9e Inner rail part 9f Extension rail part 15 Fender

Claims (5)

A pair of left and right apron upper members whose rear end is connected to a front pillar extending in the vehicle vertical direction and extending in the vehicle longitudinal direction;
A substantially rectangular hood straddled between the pair of left and right apron upper members, and a vehicle front structure comprising:
The pair of left and right apron upper members has a vehicle front portion structure having a grip portion for gripping both end sides of the hood extending in the vehicle front-rear direction in the apron upper member. The vehicle front structure according to claim 1,
The grip portion is a pair of rail portions extending in the vehicle front-rear direction,
Both ends of the hood are fitted into the pair of rail portions, and are movable relative to the rail portions in the vehicle front-rear direction. The vehicle front part structure according to claim 1 or 2,
A vehicle front structure, wherein the hood is formed with a skeleton portion extending in a vehicle width direction. The vehicle front structure according to any one of claims 1 to 3,
It further includes a pair of fenders disposed on the side of the vehicle,
The vehicle front structure, wherein the hood and the fender are continuously formed integrally. The vehicle front structure according to claim 4,
An inner panel joined to the inner surface of the hood;
The vehicle front structure according to claim 1, wherein a joint portion between the hood and the inner panel is not on an extension of the apron upper member in the vehicle vertical direction.

Images