Vehicle-body front structure
A vehicle-body front structure includes: a toe board including an upper toe board and a lower toe board joined to each other with a vehicle lower-side edge of the upper toe board overlapping a vehicle upper-side edge of the lower toe board; main frames provided on opposite sides of the vehicle-body front part in a vehicle width direction and extending in a vehicle front-rear direction; and front pillars extending in a vehicle up-down direction on opposite outer sides of the toe board in the vehicle width direction. The toe board has a closed cross section at a position where the upper and lower toe boards are overlapped. The closed cross section includes opposite ends joined to the front pillars in the vehicle width direction. The main frames are joined to the toe board at positions overlapping the closed cross section in a vehicle front view.
1 . A vehicle-body front structure comprising:
a toe board interposed between a vehicle-body front part and a vehicle interior in a vehicle and comprising an upper toe board disposed on an upper side of the vehicle and a lower toe board disposed on a lower side of the vehicle, the upper toe board and the lower toe board being joined to each other with a vehicle lower-side edge of the upper toe board overlapping a vehicle upper-side edge of the lower toe board;
main frames provided on opposite sides of the vehicle-body front part in a vehicle width direction of the vehicle and extending in a vehicle front-rear direction of the vehicle; and
front pillars extending in a vehicle up-down direction of the vehicle on opposite outer sides of the toe board in the vehicle width direction, wherein
the toe board has a closed cross section at a position where the upper toe board and the lower toe board are overlapped with each other, the closed cross section having an area larger than a cross-sectional area of a welding joint between one of the main frames and the toe board, protruding in the vehicle front-rear direction, and extending toward the opposite sides,
the closed cross section comprises opposite ends in the vehicle width direction, the opposite ends being joined to the front pillars, and
the main frames are joined to the toe board at positions overlapping the closed cross section in a vehicle front view of the vehicle,
further comprising:
a bulkhead front extending in the vehicle width direction on a vehicle upper side of the toe board and joined to the toe board,
wherein the closed cross section, the bulkhead front, and the front pillars form a looped framework that extends in the vehicle width direction.
2 . The vehicle-body front structure according to claim 1 , wherein the bulkhead front has a squared U shape with a vehicle lower side opened.
3 . The vehicle-body front structure according to claim 1 , wherein the bulkhead front is joined to the toe board and the front pillars.
4 . The vehicle-body front structure according to claim 1 , wherein the toe board is devoid of a cross member or a torque box extending in the vehicle width direction.
5 . The vehicle-body front structure according to claim 1 , wherein the closed cross section is provided by the upper toe board protruding to a vehicle rear side and the lower toe board protruding to a vehicle front side.
6 . The vehicle-body front structure according to claim 1 , wherein the upper toe board and the lower toe board are formed of steel plates having different plate thicknesses.
7 . The vehicle-body front structure according to claim 6 , wherein the lower toe board is formed of a steel plate having a thickness greater than that of the upper toe board.
8 . The vehicle-body front structure according to claim 1 , wherein the lower toe board includes beads.
9 . The vehicle-body front structure according to claim 1 , wherein the lower toe board is formed by hot pressing.
10 . The vehicle-body front structure according to claim 1 , wherein the main frames each have a rectangular closed cross-sectional shape.
11 . The vehicle-body front structure according to claim 1 , wherein each of the main frames is bent to a vehicle lower side of the toe board and further extends toward a vehicle rear side, thereby forming a main frame rear portion.
12 . The vehicle-body front structure according to claim 1 , further comprising a bumper beam extending in the vehicle width direction and joined to vehicle front-side ends of the main frames.
13 . The vehicle-body front structure according to claim 1 , wherein the toe board is joined to vehicle rear-side ends of the main frames at the welding joint.
14 . The vehicle-body front structure according to claim 1 , further comprising an upper frame disposed on a vehicle upper side of the vehicle-body front part, the upper frame having a rectangular closed cross-sectional shape and surrounding a periphery of the vehicle-body front part.
15 . The vehicle-body front structure according to claim 14 , further comprising auxiliary beams extending toward a vehicle lower side and joined to a vehicle front-side part of the upper frame, the auxiliary beams providing joining between a bumper beam and the upper frame.
16 . The vehicle-body front structure according to claim 14 , further comprising strut towers joined to a vehicle rear-side part of the upper frame and to the main frames, the strut towers providing joining between the upper frame and the main frames.
17 . The vehicle-body front structure according to claim 1 , further comprising side sills joined to vehicle lower parts of the front pillars on rear sides of the front pillars, each of the side sills being a framework extending in the vehicle front-rear direction and having a rectangular closed cross-sectional shape.
18 . The vehicle-body front structure according to claim 1 , further comprising a floor tunnel formed at a lower area of a vehicle-widthwise central part of the toe board, the floor tunnel having a U shape with a vehicle upper side bulging toward a vehicle interior inner side and with a vehicle lower side opened, and extending in the vehicle front-rear direction.
19 . The vehicle-body front structure according to claim 1 , wherein an inside of the closed cross section is filled with a foaming agent.