JP4938717B2 - Body front structure - Google Patents

Description

  The present invention relates to a vehicle body front structure having a front side frame extending in the front-rear direction of a vehicle body of an automobile and reaching a vehicle body front end portion, and a front bulkhead disposed at the vehicle body front end portion.

Conventionally, in a vehicle body front part structure, a pair of left and right front side frames are provided so as to extend along the left and right side surfaces at the front part of the vehicle body. It is connected via a front bulkhead. In such a front structure of the vehicle body, the front side frame and the cross member can be connected directly to each other at the front side frame and the position of the front side frame and the cross member can be secured in order to secure the crushing stroke of the front side frame at the time of collision. Some members (front side frames) are located at the forefront position (see, for example, Patent Document 1).
Noto 2588709

  However, in Patent Document 1, since the front side member and the cross member lower are cut and joined, there is a problem in that the strength of each frame itself is lowered and the manufacturing is difficult.

In order to solve such problems and improve the rigidity of the front portion of the vehicle body and facilitate manufacture and assembly, the present invention extends in the front-rear direction of the vehicle body (1) and A front body structure having a front side frame (11) reaching the front end of the vehicle body and a front bulkhead (17) disposed at the front end of the vehicle body, wherein the front bulkhead (17) is located above and below the vehicle body. A side member (21) having a hollow cross-sectional shape extending in the direction, and an intermediate portion of the side member (21) is crushed on a vehicle body rear side wall portion (21b) on the vehicle body front side. The side member (21) is formed so as to be in contact with the vehicle body front side wall portion (21c), and is in contact with the vehicle body front side wall portion (21c) of the vehicle body rear side wall portion (21b) of the side member (21). Part (26) With the vehicle front end capital side frame (11) is coupled, said front side frame (11) is formed in a rectangular closed cross section, the hollow cross-sectional shape of the side member (21) is, in the rear of the vehicle body The U-shaped cross-section member (21a) that opens and a lid-shaped member (21b) that closes the opening of the U-shaped cross-section member, and the vehicle body front side wall portion (21c) are formed in the U-shape. It consists of the bottom wall part of the cross-sectional member (21a), the said vehicle body rear side wall part consists of the said lid-like member (21b), and the said front side frame (11) and the said side member (21) are said U-shaped cross sections. It is connected via a connecting bracket (23) having a U-shaped cross-sectional shape that is received by being fitted into the member (21a), and both side wall portions (23a) in the U-shaped cross-sectional shape of the connecting bracket (23). Are welded to both side surfaces in the vehicle width direction of the front side frame (11), and three wall portions in the U-shaped cross-sectional shape of the connection bracket (23) and the U-shaped cross-section of the side member (21). The three wall portions of the member (21a) were welded .

In particular, well the previous SL said U-shaped cross section the bottom wall in the shape (23b) on the threaded member for bumper attachment of the connecting brackets (23) (25) is integrally provided, also, the front side frame It is preferable that a crash bead (24) serving as a fragile portion at the time of collision is provided in the vicinity of the coupling portion of (11) to the side member (23).

  As described above, according to the present invention, at the intermediate portion of the side member of the front bulkhead, the vehicle body rear side wall portion of the side member is crushed toward the vehicle body front side and brought into contact with the vehicle body front side wall portion. Since the front end of the vehicle body of the side frame is connected, the neutral members of the front bulkhead side member and the front side frame can be matched (crossed) to connect both members. The coupling efficiency between the member and the front side frame can be improved, the rigidity of the front part of the vehicle body is improved, and the steering stability is also improved. In addition, the rear body side wall of the side member of the front bulkhead has been crushed so that the side member does not need to be divided into upper and lower parts. Assembling becomes easy and manufacturing cost and time can be reduced.

  In particular, according to the second aspect, the front side frame can be coupled to the U-shaped cross-section member of the side member via the connecting bracket capable of welding the three wall portions to each other, and the bracket is fitted into the side member. It can weld in a state, and can perform a welding operation easily. According to the third aspect of the present invention, the bumper mounting screw member is provided in the connection bracket, so that a hole through which the stud bolt is inserted is provided in the side member, and the alignment between the hole and the screw member is performed on the connection bracket and the side. It becomes positioning of the welding operation with the member, and the welding operation positioned with high accuracy can be easily performed. According to claim 4, the front side frame is lengthened by the amount of the side member's rear body member being crushed to the front side of the vehicle body, so that the crash bead is positioned at a position close to the coupling portion with the side member of the front side frame. It is possible to provide suitable collision energy absorption at the time of collision.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view of a main part of a front body structure of an automobile to which the present invention is applied as viewed obliquely from the front.

  In the vehicle body front structure shown in FIG. 1, a pair of left and right front side frames that extend in the front-rear direction of the vehicle body at intervals in the left-right direction at the front portion of the vehicle body 1 as a skeleton strength member of the vehicle body front portion 11 and 12, left and right members 15 and 16 extending from the left and right front pillars 13 and 14 to the vicinity of the upper front end of the left and right front side frames 11 and 12, and the front side of the left and right front side frames 11 and 12 The front bulkhead 17 is coupled to and supported by the end portions and the vehicle body front end portions of the left and right members 15 and 16, and an engine room 18 is defined inside these.

  Each of the skeleton strength members as the vehicle body part structure may have a rectangular closed cross section formed of, for example, a U-shaped cross-section member and a plate-like lid-shaped member, and this shape is used as the skeleton strength member of the vehicle body. Since it is publicly known, its detailed description is omitted. Further, left and right wheel houses 19 and 20 for front wheels are provided in a space defined by the left and right members 15 and 16 and the left and right front side frames 11 and 12.

  The front bulkhead 17 is formed in a shape having a rectangular frame portion facing the front of the vehicle body, and the left and right side members 21. 22 is coupled to the front end portions of the front side frames 11 and 12 at an intermediate portion. Upper and lower cross members 17a and 17b extending in the vehicle body width direction in the vehicle body vertical direction constituting the frame portion of the front bulkhead 17 are provided. The upper cross member 17a includes left and right side members. The left and right rearward extending portions 17c and 17d extending from the upper left and right corners of the frame portion that is the upper end of the vehicle body 21 and 22 to the left and right members 15 and 16 extend, and the left and right rearward extending portions 17c The rear end of 17d is connected to the front ends of the left and right members 15 and 16.

  The upper cross member 17a and the left and right rear extension portions 17c and 17d are bent so as to have a U shape expanded in plan view, and the left and right side members 21 and 22 are formed at the left and right corners. The tops of are joined. Specifically, a radiator mounting bracket 28 that protrudes forward of the vehicle body is fixed to a corner portion between the upper cross member 17a and the left and right rear extending portions 17c and 17d, and serves as a lower surface of the corner portion. The upper ends of the side members 21 and 22 are welded to the lower surface of the upper cross member 17a.

  2 is a left side view of the main part of the vehicle body front structure as seen from the arrow II line of FIG. 1, and FIG. 3 is an enlarged perspective view of the main part showing the assembly procedure. The vehicle body front portion structure is bilaterally symmetric. Hereinafter, the left side portion of the vehicle body front portion will be described unless otherwise specified.

  As shown in FIGS. 2 and 3, the vehicle body front side end portion of the front side frame 11 is coupled to the side member 21 via a connection bracket 23. The connecting bracket 23 has a shape in which a steel plate is bent into a U-shaped cross section, and has a width that sandwiches both side surfaces in the vehicle width direction of the front side frame 11 from both sides with both side wall portions 23a. 11 is formed to be somewhat longer than the vertical length of the vehicle body. Then, both side wall portions 23a of the connecting bracket 23 are spot-welded to the both side surfaces of the front side frame 11 at points indicated by x marks in FIG.

  The front side frame 11 has a vertically long and deep bottom U-shaped cross-sectional member 11a, a lower lid 11b provided so as to cross at an intermediate portion in the longitudinal direction, and an applique 11c provided so as to close the opening. Are formed by welding the three members. Further, on both side surfaces of the front side frame 11, projecting crush beads (fragile portions) 24 extending in the vertical direction of the vehicle body are arranged at a plurality of locations in the full length direction (vehicle body longitudinal direction).

  The bottom wall portion 23b of the U-shaped connecting bracket 23 is fixedly provided with a total of four stud bolts 25 as screw members for attaching bumpers. Although not shown, bead-shaped concavo-convex portions for positioning with respect to the front side frame 11 are formed on both side wall portions 23a of the connection bracket 23.

  As described above, the side member 21 has a shape that forms a rectangular closed cross section by the U-shaped cross-section member 21a and the lid-shaped member 21b. However, as shown in FIG. The lid-like member 21b as the side wall portion is crushed to the front side of the vehicle body and bent until it comes into contact with the bottom wall portion 21c of the U-shaped cross-sectional member 21a as the vehicle body front side wall portion. The size of the abutting portion 26 may be such that the bottom wall portion 23b of the connecting bracket 23 can be placed.

  A portion of the side member 21 other than the contact portion 26 has a rectangular closed cross-sectional shape, and the contact portion 26 is in a state in which two plates are laminated. Accordingly, the abutting portion 26 of the side member 21 has a U-shaped cross-sectional shape due to the U-shaped cross-sectional member 21a, and the connection bracket 23 is received in a fitted state in the U-shaped cross-sectional shape portion. The contact portion 26 is provided with the same number of holes 27 through which the stud bolts 25 are inserted, and is connected to the side member 21 by inserting the stud bolts 25 into the corresponding holes 27. The bracket 23, that is, the front side frame 11 is positioned.

  The side member 21 and the connecting bracket 23 are spot-welded at four locations on the upper portion and three locations on the lower portion, as indicated by a two-dot chain line in FIG. Combined. In addition, in those welded portions, the upper and lower portions are respectively the three wall portions of the U-shaped bottom wall portion and both wall portions, and a combined state with high coupling efficiency and high rigidity is obtained.

  In this manner, the side member 21 of the front bulkhead 17 and the front side frame 11 are integrally coupled via the connection bracket 23, and the coupling structure allows the side bulkhead 17 to be viewed from the vehicle width direction as shown in FIG. The neutral axis C1 of the front side frame 11 and the neutral axis C2 of the side member 21 coincide (cross). Further, as shown in FIG. 4, when viewed from the front side of the vehicle body, both neutral axes C1 and C2 coincide (intersect). Accordingly, the rigidity of the front portion of the vehicle body can be improved and the steering stability performance can be improved together with the connection structure of the three wall portions.

  In addition, as described above, the lid-like member 21b of the side member 21 is crushed to the front side of the vehicle body, and the front side frame 11 and the side member 21 are combined without dividing the side member 21 up and down. The increase in score can be suppressed. Then, the front side frame 11 and the side member 21 can be handled as a single piece and coupled to each other in a T-shape, which facilitates manufacture / assembly and reduces manufacturing cost / time.

  In addition, since the lid-like member 21b of the side member 21 is crushed to the front side of the vehicle body, the front side frame 11 can be extended to the front side of the vehicle body by the length of the front side frame 11 being crushed. It is possible to ensure a longer collision stroke at the time of forward collision at. Furthermore, when the crash bead 24 is provided on the longer front side frame 11, it can be arranged more efficiently, and in addition to the above, collision energy absorption can be made highly efficient.

It is the principal part perspective view which looked at the vehicle body front part structure of the motor vehicle to which this invention was applied from diagonally forward. It is a principal part left view of the vehicle body front part structure seen from the arrow II line of FIG. It is a principal part expansion perspective view which shows the assembly point of a vehicle body front part structure. It is a principal part front view of the vehicle body front part structure seen from the arrow IV line of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Car body 11 Front side frame 17 Front bulkhead 21 Side member 21a U-shaped cross-section member 21b Lid-like member (vehicle body rear side wall part)
21c Car body front side wall part 26 Contact part 23 Connection bracket 23a Side wall part 23b Bottom wall part 24 Crash bead

Claims (3)

A vehicle body front structure having a front side frame extending in the front-rear direction of the vehicle body and reaching the vehicle body front end portion, and a front bulkhead disposed at the front end portion,
The front bulkhead has a hollow cross-sectional side member extending in the vertical direction of the vehicle body,
An intermediate portion of the side member is formed such that a vehicle body rear side wall portion of the side member is crushed to the vehicle body front side and comes into contact with a vehicle body front side wall portion of the side member,
A front side end of the front side frame is coupled to a portion of the side member that is in contact with the front side wall of the rear side wall of the vehicle body ,
The front side frame is formed in a rectangular closed cross-sectional shape,
The hollow cross-sectional shape of the side member is formed by a U-shaped cross-sectional member that opens to the rear of the vehicle body and a lid-shaped member that closes the opening of the U-shaped cross-sectional member, and the vehicle body front side wall portion is It consists of the bottom wall portion of the U-shaped cross-sectional member, the vehicle body rear side wall portion consists of the lid-like member,
The front side frame and the side member are coupled via a connection bracket having a U-shaped cross-sectional shape that is received by being fitted into the U-shaped cross-sectional member,
Both side wall portions in the U-shaped cross-sectional shape of the connection bracket are welded to both side surfaces in the vehicle width direction of the front side frame, and three wall portions in the U-shaped cross-sectional shape of the connection bracket and the side member A vehicle body front part structure in which three wall portions of the U-shaped cross-sectional member are welded .   The vehicle body front structure according to claim 1, wherein a screw member for mounting a bumper is integrally provided on a bottom wall portion of the connection bracket in the U-shaped cross-sectional shape. The vehicle body front part structure according to claim 1 or 2, wherein a crash bead serving as a fragile portion at the time of a collision is provided in the vicinity of a joint portion of the front side frame to the side member.

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