JP5154246B2 - Body front structure - Google Patents

Description

  The present invention relates to a vehicle body front structure that includes a front side frame that extends in the front-rear direction of a vehicle body and reaches a vehicle body front portion, and a front bulkhead disposed in the vehicle body front 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 vehicle body front structure, a part of the cross member is cut out in a concave shape, the vehicle body front side end portion of the front side frame is fitted into the recessed portion, and both members are coupled (for example, see Patent Document 1) In some cases, a part of the front side frame end portion of the front side frame is cut out in a concave shape, the end portion of the cross member is fitted into the recessed portion, and both members are coupled (for example, see Patent Document 2).
Japanese Patent No. 3814552 Japanese Patent No. 3912409

  However, in each of the above patent documents, as described above, the front side frame is provided with a cross member positioned on the lower side of the vehicle body and extending in the vehicle body width (left and right) direction. On the other hand, no consideration is given to providing a front bulkhead having side members positioned on both sides of the vehicle body in the vertical direction. Therefore, there arises a problem that the vehicle body upper side portion of the side member of the front bulkhead cannot be attached with the vehicle body front structure of each of the above-mentioned patent documents.

  Furthermore, in the thing of patent document 1, the recessed part provided in the cross member is formed by a pair of wall part which mutually opposes in a vehicle body left-right direction, and these wall parts are couple | bonded with the side surface of a front side frame. ing. In such a structure, when a load from the front side of the vehicle body is applied to the cross member, the transmission of the load to the front side frame acts as a shearing force on the joint portion between the wall portion and the side surface. Is difficult to be transmitted to the front side frame.

  Moreover, in the thing of patent document 2, the flange along the edge of the recessed part provided in the front side frame is provided in the vehicle body up-down direction both sides of the front side frame, and the flange and the corresponding side surface of the cross member are welded. Thus, the front side frame and the cross member are joined. However, if the welding is to be performed by spot welding with good productivity, the end of the cross member is open on the upper surface of the front side frame. There is a problem that can not be done.

In order to solve such a problem and to realize a vehicle body front structure capable of reliably transmitting a load from the front side and improving productivity, the present invention extends in the longitudinal direction of the vehicle body and A front body structure having a front side frame (11, 12) reaching the front of the vehicle body and a front bulkhead (17) disposed at the front of the vehicle body, wherein the front bulkhead (17) is the vehicle body Side members (21, 22) extending in the vertical direction of the side members (21, 22), the neutral shaft (C2) of the side members (21, 22) and the front side frame (11, 22). so as to intersect the body front end of the neutral axis of 12) (C1), provided so as to sandwich the vertical direction of the vehicle body to the vehicle body front side end portion of the front side frame (11, 12), the front side frame Upper and lower extensions (23, 24) having inclined portions facing the front of the vehicle body are provided on both sides in the vehicle body vertical direction at the vehicle body front end portion of the vehicle (11, 12), respectively, and the front of the side member (21, 22) The vehicle frame upper part (25) and the vehicle body lower part (26) respectively disposed on the vehicle body upper and lower sides of the front side frame (11, 12) are connected to the side frames (11, 12), and the vehicle body The vehicle body of the front side frame (11, 12) extends over the entire length of the side member (21, 22) so as to integrally connect the upper portion (25) and the vehicle body lower portion (26). The front side frame (11, 12) including the upper and lower extensions (23, 24) is provided in front of the vehicle body front side wall (21a) in contact with the front end. It is formed in a recessed shape that is cut out corresponding to the front side end of the vehicle body, and the vehicle body upper portion (25) and the vehicle body lower portion (26) of the side members (21, 22) are The side members (21, 22) are spot-welded to the inclined portions (23a, 24a) of the extensions (23, 24) from the vertical direction of the vehicle body, and the front side end portions of the front side frames (11, 12) However, the side members (21, 22) and the front side frames (11, 12) are integrated with each other by spot welding in the vehicle longitudinal direction substantially orthogonal to the vehicle body vertical direction on the vehicle body front side wall (21a). To be combined.

  In particular, the vehicle body upper portion (25) in which the coupling portions of the side members (21, 22) with the front side frames (11, 12) are respectively arranged on the vehicle body upper and lower sides of the front side frames (11, 12). ) And the vehicle body lower side portion (26), and the vehicle body front side wall portion (21a) in the side member (21, 22) integrally connecting the vehicle body upper portion (25) and the vehicle body lower portion (26). It is good to be formed by. Extensions (23, 24) having inclined portions (23a, 24a) facing the front of the vehicle body are provided on both sides of the front side end of the front side frame (11, 12) in the vehicle body vertical direction. The vehicle body upper part (25) and the vehicle body lower part (26) of (21, 22) may be coupled to the inclined parts (23a, 24a) of the extension (23, 24).

  As described above, according to the present invention, the side members of the front bulkhead are joined to the front side frame so that the neutral shafts (lines of stress 0 at the time of bending deformation) coincide with each other. The load from the front side applied to the front bulkhead can be efficiently transmitted to the front side frame, and the load absorption efficiency by the front side frame can be improved. Further, by adopting a structure in which the side member of the front bulkhead is sandwiched with respect to the front side frame, flanges can be formed on the side member and the front side frame, respectively, and spot welding can be performed on the overlapped flanges. Therefore, productivity in welding work is improved, the work efficiency of connecting the side member of the front bulkhead and the front side frame is improved, and the rigidity of the front structure of the vehicle body is improved in combination with the above neutral shaft, so that the steering stability is improved. Improves.

  In particular, according to the second aspect, the vehicle body front side portion and the vehicle body lower side portion sandwiching the front side frame in the side member of the front bulkhead are integrally connected by the vehicle body front side wall portion of the side member. The front side wall portion can be coupled to the vehicle body front side end portion of the front side frame, and the rigidity can be further enhanced. According to the third aspect of the present invention, by providing the extension having the inclined portion and connecting the vehicle body front side portion and the vehicle body lower side portion by the inclined portion, the load from the front side can be more reliably transmitted to the front side frame. .

  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 11 and 12 extending in the vehicle front-rear direction with an interval in the left-right direction of the vehicle body as a skeleton strength member of the vehicle body front portion, The left and right members 15, 16 extending from the left and right front pillars 13, 14 to the vicinity of the front side ends of the left and right front side frames 11, 12, the front side ends of the left and right front side frames 11, 12, The front bulkhead 17 is connected to and supported by the front end portions of the members 15 and 16 and the engine room 18 is defined inside the front bulkhead 17.

  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 member, and this shape is known as a skeleton strength member of the vehicle body. Detailed description thereof will be 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 has a rectangular frame portion that faces the front of the vehicle body, and the front ends of the front side frames 11 and 12 at the intermediate portions of the left and right side members 21 and 22 that constitute the frame portion in the vehicle body width direction. Combined with the department. In addition, left and right rearward extending portions 17a and 17b are provided from the upper left and right corners of the frame portion which is the vehicle body upper end of the left and right side members 21 and 22 to the left and right members 15 and 16, respectively. The rear ends of the left and right rear extending portions 17a and 17b are joined to the front ends of the left and right members 15 and 16, respectively.

  FIG. 2 is a left side view of the main part of the vehicle body front structure as seen from the arrow II line in FIG. 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 described above and as shown in FIG. 2, extensions 23 and 24 are respectively fixed to the front side end portions of the upper and lower surfaces 11 a and 11 b in the vertical direction of the vehicle body of the front side frame 11. A vehicle body upper portion 25 and a vehicle body lower portion 26 of the side member 21 of the front bulkhead 17 are fixedly provided at 24.

  The extensions 23 and 24 have a U-shaped plate-like member, and as shown in FIGS. 2 and 3, the upper and lower surfaces of the front side frame 11 with the U-shaped opening at the front side of the vehicle body. 11a and 11b are fixed in a standing state. Further, flanges 23a and 24a formed by bending outward edges of the extensions 23 and 24 outwardly are provided, and the vehicle body upper end surface and the vehicle body lower end surface of each flange 23a and 24b are respectively in front of the vehicle body. It is formed as an inclined part that faces. In addition, left and right flanges 11a formed by bending left and right side wall extending portions left and right are provided at the front end portion of the vehicle body of the front side frame 11. The front side frame 11 may have a laterally open cross-sectional shape or a closed cross-sectional shape in addition to the above-described upwardly open cross-sectional shape.

  The side member 21 may have a configuration in which the U-shaped cross-sectional member in the above description of the skeleton strength member is disposed on the rear side of the vehicle body, and the plate-shaped member is disposed on the front side of the vehicle body. The U-shaped cross-section member forming the side member 21 is cut out so as to have a concave shape corresponding to the front side end portion of the front side frame 11 including the upper and lower extensions 23 and 24 at the intermediate portion of the side member 21. ing. A vehicle body front side wall portion 21a made of a plate-like member forming the side member 21 extends over the entire length, but the side member 21 is divided into a vehicle body upper side portion 25 and a vehicle body lower side portion 26 by the notches. The vehicle body front side wall portion 21a may be divided into three or two parts, the vehicle body upper part 25 and the vehicle body lower part 26.

  A flange 25a corresponding to the flange 23a of the upper extension 23 is formed in the vehicle body upper portion 25, and similarly, a flange 26a corresponding to the flange 24a of the lower extension 24 is formed in the vehicle body lower portion 26.

  As shown in FIG. 3 and FIG. 4, the side members 21 are fitted in the front side frame 11 in the direction indicated by the arrow A, and the two members are set. The vehicle body front side end portion is sandwiched between the vehicle body upper side portion 25 and the vehicle body lower side portion 26 in the vehicle body vertical direction. Further, between the two portions 25 and 26 of the vehicle body front side wall portion 21 a is in contact with the vehicle body front end of the front side frame 11.

  Since the side member 21 is structured to be fitted into the front side frame 11 as described above, the corresponding ones of the flanges 23a, 24a, 25a, and 26a can be brought into contact with each other, and spot welding is performed. It becomes possible. Further, spot welding can be performed also at the corresponding left and right edge portions of the flange 11c and the vehicle body front side wall portion 21a.

  2 and 5, the neutral axis C1 of the front side frame 11 and the neutral axis C2 of the side member 21 intersect and intersect each other as shown in FIGS. The neutral axis is defined as a zero stress line below the axial element where tension is applied and above the axial element where compression is applied when the beam is bent. Good.

  As described above, the front side frame 11 and the side member 21 can be coupled to each other by spot welding as described above by the structure in which the neutral axes C1 and C2 are aligned and sandwiched. Productivity. In addition, since spot welding is performed with respect to the sandwiching direction of the side member 21 and the vehicle body front side wall portion 21a is also spot welded with respect to the vehicle longitudinal direction which is a direction substantially orthogonal to the sandwiching direction, rigidity in the vehicle body front structure is achieved. And the steering stability performance is improved.

  Further, when the front side frame 11 and the side member 21 have the same width in the vehicle body width direction as in the illustrated example, the collision load indicated by the arrow F in FIG. 2 is applied to the front bulkhead 17. The load can be transmitted to the front side frame 11 efficiently.

  Moreover, since the vehicle body upper side portion 25 and the vehicle body lower side portion 26 are integrally connected by the vehicle body front side wall portion 21a and the side member 21 can be handled as one member, the setability before welding is good. Further, since tension is applied to the vehicle body front side wall portion 21a with respect to the collision load, even if the collision load position with respect to the front bulkhead 17 is shifted in the vehicle vertical direction, the load is integrated with the vehicle body upper portion 25 and the vehicle body lower side. It is distributed to the portion 26 and efficiently transmitted to the front side frame 11.

  Further, since the vertical surfaces (flanges 23a, 24a) of the extensions 23, 24 are inclined so as to face the front side of the vehicle body, the side members 21 are set so as to be fitted into the front side frames 11 from the front side of the vehicle body. In this case, even if there is a slight shift in the vertical direction, the setability is further improved because the extension 23 and 24 are guided to the set position by the inclination.

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 the principal part enlarged side view seen from the arrow II line of FIG. FIG. 3 is an exploded perspective view of a vehicle body right front structure according to the present invention. It is an assembly exploded side view of the vehicle body right front structure based on this invention. It is the principal part end view seen from the arrow V line of FIG.

Explanation of symbols

11/12 Front side frame 17 Front bulkhead 21/22 Side member 21a Car body front side wall portion 23a / 24a Flange (inclined portion)
25 Car body upper part 26 Car body lower part C1 and C2 Neutral shaft

Claims (1)

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 portion, and a front bulkhead disposed at the vehicle body front portion,
The front bulkhead has a side member extending in a vertical direction of the vehicle body;
The side member is provided so as to be sandwiched from the vehicle body front side end portion of the front side frame from the vehicle body vertical direction so that the neutral shaft of the side member intersects the neutral axis of the vehicle body front side end portion of the front side frame ,
Upper and lower extensions having inclined portions facing the front of the vehicle body are provided on both sides of the vehicle body vertical direction at the vehicle body front end of the front side frame,
The connecting portion of the side member with the front side frame is integrally formed with the vehicle body upper portion and the vehicle body lower portion disposed on the vehicle body upper and lower sides of the front side frame, and the vehicle body upper portion and the vehicle body lower portion, respectively. A vehicle body front side wall portion including the upper and lower extensions by a vehicle body front side wall portion extending over the entire length of the side member so as to be connected to the vehicle body and contacting the vehicle body front end of the front side frame. Formed into a recessed shape cut out corresponding to the part,
The vehicle body upper side portion and the vehicle body lower side portion of the side member are spot-welded to the inclined portion of the upper and lower extensions from the vehicle body vertical direction of the side member, and the vehicle body front side end portion of the front side frame Is spot welded in the vehicle front-rear direction substantially orthogonal to the vehicle body vertical direction on the vehicle body front side wall portion,
A vehicle body front part structure in which the side member and the front side frame are integrally coupled.

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