JP6575852B2 - Body front structure - Google Patents

Description

  The present invention relates to a vehicle body front structure in which a side member supports a cab.

  Patent Document 1 describes a side rail that is divided into a rear main side rail and a front extension side rail. A cab mount is rigidly connected to the extension side rail.

JP 2014-156157 A

  In the structure of Patent Document 1, the front extension side rail is configured so that the strength against the compressive load in the front-rear direction is lower than that of the main side rail. It is conceivable to absorb impact energy by crushing.

  However, since the cab mount is fixed to the extension side rail, if the entire area of the extension side rail is crushed equally during a frontal collision, the cab mount will fall off the side rail (side member) and the cab will not be supported. There is a possibility that the occupant living space in the cab is narrowed.

  Accordingly, the present invention provides a vehicle body front structure capable of efficiently absorbing impact energy at the time of vehicle front collision by crushing deformation of the front end portion of the side member while suppressing cab mount dropout at the time of vehicle front collision. The purpose is to provide.

  In order to achieve the above object, the vehicle body front structure according to the first aspect of the present invention includes a side member and a cab mount. The side member integrally includes a side member main body extending in the front-rear direction and a side member extension extending linearly forward from the front end of the side member main body. The side member extension includes a cab mount attachment. The cab mount is fixed to the cab mount mounting portion of the side member, and supports the front side of the cab so as to be freely tilted.

The side member extension portion is an outer portion having an U-shaped cross section that is disposed on the outer side in the vehicle width direction and opens to the inner side in the vehicle width direction. And a reinforcing member. The extension portion outer and the extension portion inner are integrated so as to define a rectangular closed section inside to form an extension portion main body. The cab mount attachment portion is provided in the front region of the extension body. In the front region of the extension portion main body, the upper surface portion and the lower surface portion of the extension portion outer protrude beyond the extension portion inner in the vehicle width direction. The reinforcing member is disposed on the inner side in the vehicle width direction of the extension inner of the front region, and stands between the upper surface and the lower surface of the extension outer protruding from the extension inner, and the upper and lower surfaces of the extension outer It is fixed to the part and reinforces the front area. The rear region of the extension main body constitutes an energy absorbing portion whose strength against the compressive load in the front-rear direction is lower than that of the cab mount attachment portion.

  In the above configuration, the side member extension provided behind the cab mount mounting portion is provided with the energy absorbing portion whose strength against the compressive load in the front-rear direction is lower than that of the cab mount mounting portion. Crushing deformation is started from the energy absorbing portion behind the mounting portion. For this reason, it is difficult for the cab mount to drop off from the side member (cab mount mounting portion). Therefore, it is possible to efficiently absorb the impact energy by the energy absorbing portion while securing the passenger living space in the cab.

  The second aspect of the present invention is the vehicle body front structure according to the first aspect, wherein the side member extension is formed separately from the side member main body and is fixed to the side member main body.

  In the above configuration, since the side member extension is formed separately from the side member main body, the side member main body is shared among a plurality of vehicle types, and the side member extension portion having a desired strength is assembled according to the vehicle type. Can do.

  ADVANTAGE OF THE INVENTION According to this invention, the impact energy at the time of vehicle front collision can be efficiently absorbed by the crushing deformation | transformation of the front-end part of a side member, at the time of vehicle front collision, suppressing the fall of a cab mount.

It is the perspective view which looked at the vehicle body front part structure which concerns on one Embodiment of this invention from diagonally upward. It is the perspective view which looked at the front-end part of the side member of FIG. 1 from diagonally forward. It is a disassembled perspective view of the side member extension part of FIG. It is a perspective view which shows the state which fixed the cab mount to the side member of FIG. It is the top view which looked at the side member extension part of Drawing 2 from the upper part.

  Hereinafter, a vehicle body front part structure according to an embodiment of the present invention will be described with reference to the drawings. In the following description, the front-rear direction is the front-rear direction of the traveling direction of the vehicle, and the left-right direction is the left-right direction when facing the front of the vehicle. In the figure, the arrow FR indicates the front of the vehicle, the arrow IN indicates the inner side in the vehicle width direction, and the arrow UP indicates the upper side of the vehicle.

  As shown in FIGS. 1 to 5, a vehicle body frame 1 includes a pair of left and right side members 2 that extend in the front-rear direction, and a plurality of cross members 3 that extend in the vehicle width direction and connect the left and right side members 2. Have The plurality of cross members 3 include a first cross member 3A that connects the front end portions of the left and right side members 2, and a second cross member 3B that connects the left and right side members 2 behind the first cross member 3A.

  Cab mount mounting portions 10 are provided at the left and right corners of the front end of the vehicle body frame 1, and left and right cab mounts 30 that support the front side of the cab (not shown) in a tiltable manner are fixed to the cab mount mounting portion 10. (See FIG. 4).

  In the present embodiment, the side member 2 includes a long side member main body 4 extending in the front-rear direction in a region excluding the front end of the vehicle body frame 1 and a straight line from the front end of the side member main body 4 to the front at the front end of the vehicle body frame 1. The side member extension portion 5 extends in a shape, and the rear end portion of the side member extension portion 5 is coupled to the front end portion of the side member main body 4 so as to be integrated. Since the left and right side members 2 are configured substantially symmetrically, one (right side) will be described in the following description, and the other (left side) will not be described.

  The front end portion of the side member main body 4 has a rectangular cylindrical shape that opens forward and defines a closed space inside, and the main body upper surface portion 41, the main body lower surface portion 42, the main body outer surface portion 43, and the main body inner side surface portion 44 are integrated. Have. The main body upper surface portion 41 and the main body lower surface portion 42 are spaced apart from each other in the vertical direction, and the main body outer surface portion 43 and the main body inner side surface portion 44 are spaced from each other in the vehicle width direction and are opposed to each other.

  The side member extension portion 5 includes an extension portion outer 6 on the outer side in the vehicle width direction, an extension portion inner 7 on the inner side in the vehicle width direction, and a stiffener (reinforcing member) 8. The extension portion outer 6, the extension portion inner 7 and the stiffener 8 are all formed by bending a metal plate into a predetermined shape, and the extension portion outer 6 and the extension portion inner 7 are integrated into an extension portion main body 9. Form. A cab mount attaching portion 10 is provided in the front region 9F of the extension main body 9, and the stiffener 8 reinforces the front region 9F. A recess 21 described later is formed in the rear region 9R behind the front region 9F.

  The extension portion outer 6 has a U-shaped cross section in which a plate-like extension portion outer upper surface portion 11 and an extension portion outer lower surface portion 12 bend inward in the vehicle width direction from the upper end and the lower end of the plate-like extension portion outer side surface portion 13. Yes, opening inward in the vehicle width direction. The extension portion inner 7 has a U-shaped cross section in which a flat plate-like extension portion inner upper surface portion 14 and an extension portion inner lower surface portion 15 are bent and extended outward in the vehicle width direction from the upper and lower ends of the flat plate-like extension portion inner side surface portion 16. Yes, open to the outside in the vehicle width direction.

  The extension outer surface 11 has a rear upper narrow portion 18 and a front wide upper portion 17 projecting inward in the vehicle width direction from the upper narrow portion 18. The extended portion outer lower surface portion 12 includes a rear lower narrow portion 20 facing the upper narrow portion 18 and a front lower portion projecting inward in the vehicle width direction from the lower narrow portion 20 and facing the upper wide portion 17. It has the wide part 19 integrally.

  The extension main body 9 is formed by integrating the extension outer 6 and the extension inner 7. The extension portion outer 6 and the extension portion inner 7 are formed by inserting the extension portion inner 7 from the vehicle width direction inside between the extension portion outer upper surface portion 11 and the extension portion inner lower surface portion 12 and extending the extension portion inner upper surface portion 14. The outer surface of the extension outer surface 11 is overlapped with the upper surface of the outer portion 11 from below, and the lower surface portion 15 of the extension inner surface is contacted with the upper surface of the lower surface of the extension portion 12 from above. Are joined together by welding the extension portion outer lower surface portion 12 and the extension portion inner lower surface portion 15, and a rectangular closed cross section is defined therein.

  The upper wide portion 17 and the lower wide portion 19 are disposed in the front region 9F of the extension main body 9 and protrude inward in the vehicle width direction from the extension inner 7 (extension inner side surface 16). In the front region 9F, substantially the entire region of the extension inner upper surface portion 14 overlaps with the extension outer surface 11 (upper wide portion 17), and substantially the entire region of the extension inner lower surface portion 15 extends in the extension outer lower surface portion 12 (lower wide portion). 19). On the other hand, in the rear region 9R of the extension portion main body 9, the vehicle width direction outer side portion of the extension portion inner upper surface portion 14 overlaps the extension portion outer upper surface portion 11 (upper narrow portion 18), and the extension portion inner lower surface portion. 15, the outer portion in the vehicle width direction overlaps the extension outer lower surface portion 12 (the lower narrow width portion 20). Thus, the width in the vehicle width direction of the extension portion outer upper surface portion 11 and the extension portion outer lower surface portion 12 is different between the front region 9F and the rear region 9R (the width of the front region 9F is larger than the width of the rear region 9R). Therefore, the rigidity with respect to the compressive load in the front-rear direction is higher in the front region 9F than in the rear region 9R. A region of the upper wide portion 17 that protrudes inward in the vehicle width direction from the extension inner 7 constitutes the cab mount attachment portion 10.

  The extension outer side surface portion 13 of the rear region 9R of the extension portion main body 9 has a recess 21 as an easily deformable portion that is easily deformed due to concentration of stress when a compressive load in the front-rear direction is applied to the side member extension portion 5. Is formed. The concave portion 21 is a groove shape that is recessed in an arc shape inward in the vehicle width direction, and extends linearly in the vertical direction over substantially the entire vertical direction of the extension outer side surface portion 13.

  The rear region 9R of the extension main body 9 has a rectangular cylindrical shape in which the rear end 22 is narrowed through a step, and the rear end 22 of the extension main body 9 is inserted into the front end opening of the side member main body 4 from the front. The side member extension 5 and the side member main body 4 are integrated by welding the boundary portion between the extension main body 9 and the side member main body 4 over substantially the entire circumference.

  The stiffener 8 has a substantially Z shape integrally including a front plate portion 23, a rear plate portion 24, and an intermediate plate portion 25, and the rear end portion of the upper wide portion 17 and the rear wide portion 19 of the extension portion main body 9. It is arranged in a standing posture between the ends. The intermediate plate portion 25 stands up crossing the front-rear direction (along the vehicle width direction), and the front plate portion 23 extends from the outer edge of the intermediate plate portion 25 in the vehicle width direction so as to be bent forward. The portion 24 extends from the inner edge of the intermediate plate portion 25 in the vehicle width direction by bending backward.

  The region of the stiffener 8 excluding the rear portion of the rear plate portion 24 is disposed in the front region 9F and overlaps the upper wide portion 17 and the lower wide portion 19 in the vertical direction. In the region excluding the rear portion of the rear plate portion 24, the upper edge portion and the lower edge portion of the stiffener 8 are welded to the lower surface of the upper wide portion 17 and the upper surface of the lower wide portion 19, respectively. Further, the rear plate portion 24 overlaps the inner side surface in the vehicle width direction of the extension inner side surface portion 16 from the inner side in the vehicle width direction and is welded to the extension inner side surface portion 16. The stiffener 8 fixed to the extension body 9 reinforces the front region 9F.

  The end portion of the first cross member 3A is inserted between the upper wide portion 17 and the lower wide portion 19 from the inner side in the vehicle width direction. The upper plate portion (cross member upper plate portion) 31 of the first cross member 3A is coupled to the upper wide portion 17 in a state of being in surface contact with the upper wide portion 17 from below, and the lower plate portion (cross member lower plate portion). 32 is coupled to the lower wide portion 19 in a state of being in surface contact with the lower wide portion 19 from above. The cross member upper plate portion 31 constitutes the cab mount attachment portion 10 together with the upper wide portion 17. The end portion of the second cross member 3B is coupled to the front end portion of the side member main body 4.

  A plurality of mount mounting holes 26 penetrating in the vertical direction are formed in the cab mount mounting portion 10. In the present embodiment, the mount attachment holes 26 are formed at a total of three locations, two on the front left and right and one on the rear. The two front mount mounting holes 26 are formed in a portion where the upper wide portion 17 and the cross member upper plate portion 31 overlap with each other, and pass through the upper wide portion 17 and the cross member upper plate portion 31. One mounting attachment hole 26 on the rear side is on the inner side in the vehicle width direction of the front plate portion 23 of the stiffener 8 and in front of the intermediate plate portion 25, in a portion of the upper wide portion 17 that does not overlap the cross member upper plate portion 31. It is formed. The cab mount 30 is placed on the cab mount mounting portion 10 and is fixed to the cab mount mounting portion 10 by a bolt (not shown) that passes through the mount mounting hole 26.

  According to the present embodiment, the upper wide portion 17 and the lower wide portion 19 are provided in the front region 9F including the cab mount mounting portion 10, and the front region 9F is reinforced by the stiffener 8, so When the rigidity of the front region 9F increases and a compressive load in the front-rear direction acts on the side member extension 5, the front region 9F becomes difficult to deform. Further, since the concave portion 21 is formed in the rear region 9R, the rear region 9R is easily crushed and deformed before the front region 9F when a longitudinal compressive load is applied to the side member extension 5. . In other words, the rear region 9 </ b> R is disposed behind the cab mount attaching portion 10 and serves as an energy absorbing portion whose strength against a compressive load in the front-rear direction is lower than that of the cab mount attaching portion 10.

  As described above, since the rear region 9R having a strength against the compressive load in the front-rear direction lower than that of the cab mount mounting portion 10 is provided behind the cab mount mounting portion 10, the cab mount mounting portion at the time of the vehicle front collision. The crushing deformation is started from the rear rear region 9R of 10. For this reason, it becomes difficult for the cab mount 30 to drop off from the side member 2 (cab mount mounting portion 10), and impact energy can be efficiently absorbed by the rear region 9R while ensuring a passenger living space in the cab.

  Further, since the side member extension 5 is formed separately from the side member main body 4, the side member main body 4 is shared among a plurality of vehicle types, and the side member extension 5 having a desired strength is assembled according to the vehicle type. Can be attached.

  As mentioned above, although the embodiment to which the invention made by the present inventor is applied has been described, the present invention is not limited by the discussion and the drawings that form part of the disclosure of the present invention according to this embodiment. That is, it is needless to say that other embodiments, examples, operation techniques, and the like made by those skilled in the art based on this embodiment are all included in the scope of the present invention.

  For example, the side member extension 5 may be formed integrally with the side member main body 4. Further, another reinforcing member may be provided instead of or in addition to the stiffener 8, and another easily deformable portion may be provided instead of or in addition to the recess 21. Further, the strength against the compressive load may be made different between the front region 9F and the rear region 9R, for example, by forming the plate thickness of the rear region 9R thinner than the front region 9F.

  The vehicle body front structure of the present invention can be widely applied to vehicles in which a cab mount is fixed to the front end of a side member.

DESCRIPTION OF SYMBOLS 1 Body frame 2 Side member 3 Cross member 4 Side member main body 5 Side member extension part 6 Extension part outer part 7 Extension part inner part 8 Stiffener 9 Extension part main part 9F Extension part main part front side area | region 9R Extension part main part rear side area | region (energy absorption) Part)
10 Cab mount mounting portion 17 Upper wide portion 19 Lower wide portion 21 Recessed portion 30 Cab mount

Claims (2)

A side member main body that extends in the front-rear direction, and a side member extension that extends linearly forward from the front end of the side member main body, and the side member extension includes a cab mount mounting portion;
A cab mount that is fixed to the cab mount mounting portion of the side member and supports the front side of the cab so as to be tiltable.
The side member extension portion is disposed on the outer side in the vehicle width direction and opens to the inner side in the vehicle width direction, and extends to the inner side in the vehicle width direction. An extension inner and a reinforcing member;
The extension outer and the extension inner are integrated so as to define a rectangular closed section inside to form an extension main body,
The cab mount mounting portion is provided in a front region of the extension body.
In the front region of the extension body, an upper surface portion and a lower surface portion of the extension portion outer project inward in the vehicle width direction from the extension portion inner,
The reinforcing member is disposed on an inner side in the vehicle width direction of the extension inner of the front region, and stands between an upper surface portion and a lower surface portion of the extension outer projecting from the extension inner, and the extension portion It is fixed to the upper surface portion and the lower surface portion of the outer to reinforce the front region,
The rear body region of the extension part body constitutes an energy absorbing part whose strength against a compressive load in the front-rear direction is lower than that of the cab mount attaching part. The vehicle body front structure according to claim 1,
The vehicle body front part structure, wherein the side member extension is formed separately from the side member main body and is fixed to the side member main body.

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