JP4810233B2 - Front body structure of automobile - Google Patents

Description

  The present invention includes a pair of front side frames disposed in a vehicle front-rear direction, a bumper beam disposed in a vehicle width direction to which front ends of the pair of front side frames are coupled, and a lower portion of the pair of front side frames. A sub-frame to be disposed; a cross member disposed below the bumper beam in the vehicle width direction and connected to the front end of the sub-frame; and a front end of the pair of front side frames and both ends of the cross member in the vertical direction The present invention relates to a front body structure of an automobile including a pair of connecting members to be connected.

The front ends of the left and right upper stringers (front side frame of the present invention) are connected to the bumper, and the front ends of the left and right lower stringers (subframes of the present invention) arranged in parallel below the upper stringer are bumper Are connected to a horizontal beam (cross member of the present invention) arranged in parallel to the lower part of the upper part, the front end of the upper stringer and the front end of the lower stringer are connected by left and right connecting members extending in the vertical direction, and the lower stringer Patent Document 1 below discloses that the rear end of the vehicle is connected to the upper stringer with a low-rigidity connecting member so that the lower stringer is crushed and the collision load is absorbed when the vehicle collides.
Special table 2003-513856 gazette

  By the way, when the host vehicle having the above-described conventional vehicle body front structure collides with the side surface of another vehicle, the upper stringer having higher rigidity than the lower stringer is located higher than the side sill of the other vehicle. The upper stringer may collide with a low-rigidity door or center pillar of another vehicle and penetrate into the vehicle interior.

  The present invention has been made in view of the above-described circumstances, and it is an object of the present invention to minimize damage to the side face of another vehicle while ensuring the collision safety performance of the own vehicle at the time of collision with the side face of the other vehicle. .

To achieve the above object, according to the invention described in claim 1, a pair of right and left front side frames disposed in the longitudinal direction of the vehicle body, it is arranged in the vehicle width direction of the pair of left and right front side frames A bumper beam to which a front end is coupled; a subframe disposed below the pair of left and right front side frames; a cross member disposed below the bumper beam in a vehicle width direction and coupled to the front end of the subframe; In the front vehicle body structure of an automobile comprising a pair of left and right connecting members that vertically connect the front ends of the pair of left and right front side frames and both ends of the cross member, the bumper beam, the cross member, and the pair of left and right constitutes the frame of the rigid body front portion of the vehicle body by a connecting member, the front of the pair of left and right front side frames Wherein the portion coupled to the upper end of the connecting member, provided with crush easily shock absorbing portion respectively in the longitudinal direction of the vehicle body load than the rear portion than partial, vehicle collision in which the impact absorbing portion is crushed A vehicle front body structure is proposed in which the cross member is connected to the front end of the subframe so as to be pivotable rearward about an axis extending in the vehicle width direction so that the collapse is sometimes promoted. The

According to the invention described in claim 2, in addition to the structure of claim 1, a bead that can be crushed by a load in the vehicle longitudinal direction is formed on the upper part of the pair of left and right connecting members, and A front body structure of an automobile is proposed in which an upper plate protruding forward from the front end is welded to the upper surface of the cross member .

  The front cross member 18 of the embodiment corresponds to the cross member of the present invention.

According to the configuration of claim 1, the bumper beam connected to the front ends of the pair of left and right front side frames, the cross member connected to the front ends of the subframe, the front ends of the pair of left and right front side frames, and both ends of the cross member Since the frame-shaped structure is formed by a pair of left and right connecting members that connect the vehicle in the vertical direction, it is possible to receive the collision load with the frame-shaped structure when the vehicle collides with another vehicle (that is, input to the bumper beam). Can be absorbed and distributed to the sub-frame via the frame composed of the bumper beam, cross member, and left and right connecting members), compared to the case where the conventional bumper beam alone receives the collision load. The input point of the load to the other vehicle is lowered. In addition, a pair of front side frames connected to the bumper beam are provided with a pair of shock absorbing parts that are easily crushed by a load in the longitudinal direction of the vehicle body compared to the rear part of the front side frames, and the shock absorbing parts The cross member is connected to the front end of the subframe so as to be able to rotate backward about an axis extending in the vehicle width direction so that the crushing is promoted when the vehicle collides. While the vehicle's cross member collides with the rigid side sill of the other vehicle to absorb the impact, the bumper beam of the host vehicle collides with the low-rigidity door or center pillar of the other vehicle and the impact absorbing portion of the front side frame is By crushing, it is possible to minimize the bumper beam and the front side frame of the host vehicle from penetrating into the cabin of the other vehicle.

That is, when the own vehicle collides with the side of another vehicle, the cross member of the own vehicle collides with the side sill of the other vehicle almost simultaneously with the bumper beam of the own vehicle colliding with the door and center pillar of the other vehicle. At this time, the side sill and the floor frame of the other vehicle colliding with the cross member of the host vehicle have higher rigidity than the door and the center pillar, so that they are not greatly deformed at the time of the collision. Furthermore, even if the bumper beam of the host vehicle collides with the door and center pillar of the other vehicle as described above, the shock absorbing portion of the front side frame connected to the rear surface of the bumper beam is easily crushed by the load input from the other vehicle. Thus, the door and the center pillar are not greatly deformed toward the vehicle interior, and the safety of the occupant of the other vehicle is ensured, and at this time, the cross member is rotated backward together with the left and right connecting members, Crushing of the shock absorbing portion of the front side frame is promoted. In addition, even if the rigidity of the front side frame is reduced by providing the impact absorbing portion, the high-rigidity cross member and the sub frame support the collision load, so that the collision safety of the host vehicle is sufficiently ensured. .

According to the second aspect of the present invention, the bead that can be crushed by the load in the longitudinal direction of the vehicle body is formed on the upper part of the pair of connecting members. The crushing of the absorption part is promoted, and at this time, the upper plate of the front end of the sub-frame is easily bent, so that the cross member rotates backward together with the left and right connecting members, so that the shock absorption part of the front side frame is Promotes crushing. Therefore, it is possible to more reliably prevent the bumper beam and the front side frame from penetrating into the cabin of the other vehicle.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

  1 to 5 show an embodiment of the present invention. FIG. 1 is a perspective view showing a skeleton of a front portion of a vehicle body of an automobile, FIG. 2 is a view taken in the direction of the arrow in FIG. 1, and FIG. FIG. 4 is an enlarged sectional view taken along line 3-3, FIG. 4 is an enlarged sectional view taken along line 4-4 of FIG. 1, and FIG.

  As shown in FIGS. 1 and 2, left and right front side frames 12 and 12 extending in the longitudinal direction of the vehicle body are disposed along the left and right sides of an engine room 11 formed at the front of the vehicle body. The front ends of the side frames 12, 12 are connected by bolts 14 to the rear surface of the bumper beam 13 extending in the vehicle width direction. A subframe 15 that supports an unillustrated engine and front wheel suspension includes left and right subframe bodies 16 and 16 extending in the longitudinal direction of the vehicle body, and a rear cross member 17 that connects the rear ends thereof in the vehicle width direction. The front ends of the left and right subframe bodies 16, 16 are connected to a front cross member 18 extending in the vehicle width direction. The front ends of the left and right front side frames 12 and 12 are connected to both ends of the front cross member 18 by left and right connecting members 19 and 19 extending in the vertical direction. The bumper beam 13, the front cross member 18 and the left and right connecting members 19, 19 form a rectangular frame at the front of the vehicle body. The height of the front cross member 18 substantially matches the height of the side sill of a general vehicle.

  The front portions of the left and right front side frames 12 and 12, that is, the portions connected to the bumper beams 13 and the upper ends of the left and right connecting members 19 and 19 are shock-absorbing portions 12a, which can be easily crushed compared to the rear portions. 12a is constituted by another member and is integrally coupled to the rear portion by bolts 20.

  As apparent from FIG. 3, only the upper plates 16a, 16a protrude forward from the front ends of the subframe bodies 16, 16 having a rectangular cross-section box structure, and the upper plates 16a, 16a have a rectangular cross-section. The front cross member 18 is welded to the upper surface. Therefore, when a load from the front of the vehicle body is input, the front cross member 18 and the left and right connecting members 19 and 19 can be united and can be rotated rearward of the vehicle body using the base portions of the upper plates 16a and 16a as fulcrums 16b and 16b. It is.

  As is clear from FIG. 2 and FIG. 4, in the upper part of the left and right connecting members 19, 19 having a box structure with a rectangular cross section, that is, in the vicinity of the portion connected to the bumper beam 13 and the left and right front side frames 12, 12, A plurality of long and short beads 19a extending in the vertical direction are formed in parallel.

  The left and right subframe bodies 16 and 16, the front cross member 18, the left and right connecting members 19 and 19, the shock absorbing portions 12a and 12a of the left and right front side frames 12 and 12, and the bumper beam 13 are assembled in advance as subassemblies. The shock absorbing parts 12a, 12a are fastened to the main body parts of the left and right front side frames 12, 12 with bolts 20 ..., and the sub-frame main bodies 16, 16 are fastened to the rear cross member 17 with bolts 25, 25. It is mounted on the car body.

  Next, the operation of the embodiment of the present invention having the above configuration will be described.

  The vehicle body front structure of the vehicle according to the present embodiment includes a bumper beam 13 connected to the front ends of the left and right front side frames 12, 12, a front cross member 18 connected to the front end of the subframe 15, Since the frame-like structure formed by the connecting members 19 and 19 is provided, the collision load can be received by the frame-like structure at the time of collision with another vehicle, and the collision load can be achieved only with the conventional bumper beam. The load input point is lower than when receiving the load.

  That is, in the conventional vehicle body front structure, as shown in FIG. 6, when the own vehicle collides with the side surface of the other vehicle, the bumper beam 13 of the own vehicle is positioned higher than the side sill 23 of the other vehicle. The beam 13 collides with the door 21 and the center pillar 22 of the other vehicle. At this time, since the front side frames 12 and 12 have relatively high rigidity, the door 21 and the center pillar 22 of another vehicle having relatively low rigidity may be greatly deformed.

  On the other hand, in the vehicle body front structure of the present embodiment, when the own vehicle collides with the side surface of the other vehicle as shown in FIG. Almost simultaneously with the collision, the front cross member 18 of the host vehicle collides with the side sill 23 of the other vehicle. At this time, the side sill 23 and the floor frame 24 of the other vehicle that collide with the front cross member 18 of the host vehicle are higher in rigidity than the door 21 and the center pillar 22, so that they are not greatly deformed during the collision.

  Further, even if the bumper beam 13 of the own vehicle collides with the door 21 and the center pillar 22 of another vehicle, as shown in FIG. 2B, the shock absorbing portions of the front side frames 12 and 12 that are continuous with the rear surface of the bumper beam 13 12a and 12a are easily crushed by the load input from the other vehicle, so that the door 21 and the center pillar 22 are not greatly deformed toward the vehicle interior, and the safety of passengers of the other vehicle is ensured.

  At this time, as shown in FIG. 2B, the upper plates 16a, 16a of the front ends of the left and right subframe bodies 16, 16 of the subframe 15 are easily bent at the fulcrums 16b, 16b, and the front cross member 18 is By rotating backward together with the connecting members 19, 19, the crushing of the impact absorbing portions 12 a, 12 a of the front side frames 12, 12 is promoted. Further, as shown in FIGS. 2B and 4, the upper portions of the left and right connecting members 19, 19 are easily crushed in the front-rear direction by the action of the beads 19 a. , 12a is further promoted.

  As described above, when the host vehicle collides with another vehicle in a side surface, the front part of the bumper beam 13 and the front side frames 12 and 12 of the host vehicle is minimized to penetrate into the vehicle interior of the other vehicle. Can do. Further, even if the rigidity of the front side frames 12 and 12 is reduced by providing the shock absorbing parts 12a and 12a, the highly rigid front cross member 18 and the sub frame 15 support the collision load. Collision safety is also sufficiently secured.

  Further, since the bumper beam 13, the front cross member 18 and the left and right connecting members 19 and 19 form a rectangular frame, the load input to the bumper beam 13 due to the collision is distributed to the subframe 15 via the frame. As a result, it is possible to compensate for a decrease in the shock absorbing capability due to the provision of the shock absorbing portions 12a, 12a, and to sufficiently ensure the collision safety at the time of the frontal collision.

  The embodiments of the present invention have been described above, but various design changes can be made without departing from the scope of the present invention.

  For example, in the embodiment, the means for rotatably connecting the front cross member 19 to the front end of the subframe 15 is constituted by the fulcrums 16b and 16b of the upper plates 16a and 16a of the subframe bodies 16 and 16. The structure of the pivotally connecting means is arbitrary.

Perspective view showing the skeleton of the front part of the vehicle body 2 direction view of FIG. 3-3 enlarged sectional view of FIG. 4-4 enlarged cross-sectional view of FIG. Action explanatory diagram at the time of collision with other vehicles Action explanatory diagram at the time of collision with other vehicles according to the conventional example

12 Front side frame 12a Shock absorber 13 Bumper beam 15 Subframe 18 Front cross member (cross member)
19 Connecting member 19a Bead

Claims (2)

A pair of left and right front side frames (12) disposed in the longitudinal direction of the vehicle body;
A bumper beam (13) disposed in the vehicle width direction and connected to the front ends of the pair of left and right front side frames (12);
A subframe (15) disposed below the pair of left and right front side frames (12);
A cross member (18) disposed in the vehicle width direction below the bumper beam (13) and connected to the front end of the subframe (15);
A pair of left and right connecting members (19) for vertically connecting the front ends of the pair of left and right front side frames (12) and both ends of the cross member (18);
In the front body structure of an automobile comprising
The bumper beam (13), the cross member (18), and the pair of left and right connecting members (19) constitute a rigid frame at the front of the vehicle body,
The part of the front part of the pair of left and right front side frames (12) that is connected to the upper end of the connecting member (19) can be easily crushed by a load in the longitudinal direction of the vehicle body as compared with the rear part of the part. provided with shock absorbing portion (12a), respectively, so that the impact absorbing portion (12a) is its crushing during a vehicle collision to crushing is facilitated, the cross member (18) at the front end of the subframe (15) A front body structure of an automobile, wherein the front body structure is connected to be pivotable backward about an axis extending in the vehicle width direction. A bead (19a) that can be crushed by a load in the longitudinal direction of the vehicle body is formed on the upper part of the pair of left and right connecting members (19), and an upper plate (16a) that protrudes forward from the front end of the subframe (15). The front body structure of an automobile according to claim 1, characterized in that it is welded to the upper surface of the cross member (18) .

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