JP6593789B2 - Body structure - Google Patents

Description

  The present invention relates to a vehicle body structure under a vehicle.

  Generally, it has a floor panel as the lower structure of the vehicle. The floor panel consists of a front floor panel and a rear floor panel with a high floor connected through a step behind the front floor panel, and a fuel tank mounted below the rear floor panel. Is done. In recent years, there has been an increase in the number of vehicle body structures that increase the interior space of a vehicle by lowering the rear floor panel while securing the capacity of the fuel tank. For example, Patent Document 1 describes a vehicle body structure in which a lower surface of a fuel tank is lower than a lowermost surface of a front floor panel, and a protective member is attached to the front floor panel ahead of the fuel tank. .

  The protective member protrudes downward from the floor panel so that the lower end edge is located below the lower surface of the fuel tank, and the protective member can protect the fuel tank from contact with an obstacle.

JP 2006-21635 A

  However, in a state where the lower surface of the fuel tank protrudes greatly downward with respect to the floor panel in order to widen the vehicle interior space, the area where the protective member protrudes downward from the floor panel becomes large, and Air resistance will increase.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a vehicle body structure capable of protecting a fuel tank and suppressing air resistance during traveling.

In order to achieve the above object, a vehicle body structure of the present invention includes a pair of left and right side frames that are positioned below a floor panel and extend in the front-rear direction of the vehicle body, and a fuel disposed between the pair of side frames. And a protective member disposed at a front side of the vehicle body relative to the tank and having a lower end edge positioned below the lower surface of the fuel tank . A tunnel structure part protruding in the direction, and the protective member is provided on both sides of the tunnel structure part and protrudes downward and extends in the front-rear direction, and is fixed to a pair of tunnel side frames, Both ends are fixed to the pair of side frames, and a ventilation space is provided between the floor panel and spaced apart from the floor panel.

  According to this, since the lower end edge of the protection member is positioned below the lower surface of the fuel tank, the fuel tank can be protected from contact with an obstacle. Moreover, since the ventilation space is provided between the protection member and the floor panel, air resistance due to the protection member can be suppressed. Further, the protection member is fixed to the left and right side frames, and the rigidity of the vehicle body is improved.

  According to this, the relative movement between the side frame and the tunnel side frame can be suppressed by the protective member, and the rigidity of the vehicle body structure can be improved.

In the vehicle body structure according to claim 2 , in the above invention, the protection member may be provided on the pair of side frames and the pair of tunnel side frames located on both sides of the rear end portion of the tunnel structure portion. It is fixed.

  According to this, the rear end portion of the tunnel structure portion is easily affected by the bending of the floor panel and is easy to open in the width direction, but the protective member is fixed to the side frames and the tunnel side frames on both sides of the rear end portion. Thus, it is possible to prevent the rear end portion of the tunnel structure portion from opening in the width direction.

According to a third aspect of the present invention, in the vehicle body structure according to the third aspect , the protective member has a C-shape in a plan view when both side portions extend rearward from the tunnel side frame toward the side frame. It is characterized by being.

  According to this, traveling wind can be guided to both sides of the vehicle body by the C-shaped protective member, and air resistance can be reduced.

According to a fourth aspect of the present invention, in the vehicle body structure according to the fourth aspect , the protection member includes a pair of members having one end fixed to the side frame and the other end fixed to the tunnel side frame. It is characterized by that.

  According to this, the aerodynamic performance can be further improved by eliminating the air resistance of the protective member below the tunnel structure.

The vehicle body structure described in claim 5 is characterized in that, in the above invention, the protective member has a cross-sectional shape that suppresses air resistance of traveling wind.

  According to this, the air resistance by a protection member can be suppressed more.

  According to the vehicle body structure according to the present invention, the fuel tank can be protected and an increase in air resistance can be suppressed.

The perspective view which looked at the vehicle body structure which concerns on 1st Embodiment of this invention from the lower surface side. Sectional drawing along the II-II line of FIG. Sectional drawing along the III-III line of FIG. The perspective view of the protection member shown in FIG. The principal part enlarged view of FIG. FIG. 4 is a cross-sectional view similar to FIG. 3, illustrating the flow of air during travel. The principal part enlarged view of FIG. The principal part enlarged view of FIG. The perspective view which looked at the vehicle body structure which concerns on 2nd Embodiment of this invention from the lower surface side.

  FIG. 1 is a perspective view of the vehicle body structure according to the first embodiment of the present invention viewed from the lower surface side, and FIG. 2 is a cross-sectional view taken along line II-II in FIG. The vehicle body structure in the lower portion of the vehicle has a pair of left and right side sills 62 extending in the front-rear direction along both sides of the lower portion of the vehicle body, a floor panel 10 installed between the side sills 62, and a lower side of the floor panel 10. A pair of left and right side frames 20 extending in the front-rear direction and a protection member 30 extending in the vehicle width direction and fixed at both ends between the pair of side frames 20 are provided. The fuel tank 40 is disposed on the lower surface side of the floor panel 10 and between the pair of side frames 20, and the protection member 30 is disposed in front of the fuel tank 40.

  The floor panel 10 is a plate-like member that constitutes the floor surface of the vehicle body, and includes a front floor panel 11 positioned in front of the vehicle body and a rear floor panel 12 positioned in the rear of the vehicle body. As shown in FIGS. 1 to 3, the front floor panel 11 has a tunnel structure portion 13 that protrudes inward (inner side) of the vehicle body at the center in the width direction. In the rear floor panel 12, the height of the lower surface 12 a is higher than the position of the lower surface 11 a of the front floor panel 11.

  The tunnel structure portion 13 extends in the front-rear direction of the vehicle body, and a pair of tunnel side frames 50 that project downward from the vehicle body are provided on both sides of the tunnel structure portion 13.

  The tunnel side frame 50 is provided close to the tunnel structure portion 13, protrudes downward so as to be continuously connected to the wall surface of the tunnel structure portion 13, and extends in the front-rear direction along the tunnel structure portion 13. As shown in FIG. 7, the tunnel side frame 50 is a substantially U-shaped (U-shaped) member having an open top, having a side wall portion 51 facing each other and a bottom portion 52 connecting the side wall portion 51. There is a flange portion 53 on the opening side of the side wall portion 51 that serves as an attachment site for the front floor panel 11.

  As shown in FIG. 3, a step is formed at the boundary between the front floor panel 11 and the rear floor panel 12 in the longitudinal direction of the vehicle body, and the first cross member 60 is disposed as a rigid member at the step. Is done. The first cross member 60 extends in the vehicle width direction between the pair of side frames 20. Further, on the rear side of the first cross member 60, a second cross member 61 is disposed as a rigid member, which extends between the pair of side frames 20 and extends in the vehicle width direction. Note that the front floor panel 11 and the rear floor panel 12 may be separate members or may be formed integrally.

  The pair of side frames 20 are located on both sides in the width direction of the floor panel 10 and extend from the front floor panel 11 to the rear floor panel 12. As shown in FIG. 7, the side frame 20 is a substantially U-shaped (U-shaped) member having a side wall portion 21 facing each other and a bottom portion 22 connecting the side wall portion 21 and having an open top. In addition, the side wall 21 has a flange portion 25 on the opening side of the side wall portion 21 that serves as an attachment site for the floor panel 10. The side frame 20 includes a pair of left and right front side frames 23 located on the front floor panel 11 side and a pair of left and right rear side frames 24 located on the rear floor panel 12 side. The rear end of the front side frame 23 and the front end of the rear side frame 24 are connected to each other at a boundary portion between the front floor panel 11 and the rear floor panel 12.

  In the present embodiment, the side frame 20 and the tunnel side frame 50 are separate from the floor panel 10 and are attached to the lower surface of the floor panel 10 using a fixing means such as spot welding.

  The fuel tank 40 is disposed on the lower surface side of the rear floor panel 12, between the pair of rear side frames 24, and between the first cross member 60 and the second cross member 61. The fuel tank 40 is supported by a plurality of belts 42 extending in the front-rear direction along the lower surface of the fuel tank 40, and one end of the belt 42 is coupled to the first cross member 60 using a bolt or the like, and the other end Are coupled to the second cross member 61 using bolts or the like.

  As shown in FIG. 3, the lower surface 41 of the fuel tank 40 is located below the lower surface 11 a of the front floor panel 11 that forms the lowermost surface of the floor panel 10. In FIG. 3, the belt 42 is omitted. In the present embodiment, the fuel tank 40 has a bowl shape in which the lower surface 41a at the center in the vehicle width direction is concave and the lower surfaces 41b on both sides thereof are convex, and the convex lower surface 41b is the outermost surface of the front floor panel 11. It is located below the lower surface 11a. The concave lower surface 41a is located behind the tunnel structure 13 as shown in FIGS.

  The protection member 30 protects the fuel tank 40 from contact with obstacles such as stones during traveling, and is disposed in front of the fuel tank 40. The protection member 30 extends in the vehicle width direction. In the present embodiment, the protection member 30 has a substantially bilaterally symmetric shape, and is installed between the left and right side frames 20, and as shown in FIG. A pair of first mounting portions 32 that are positioned, a pair of second mounting portions 33 that are positioned between the first mounting portions 32, and a pair that are positioned between the first mounting portion 32 and the second mounting portion 33 It has the protection part 31 and the connection part 34 located between a pair of 2nd attachment parts 32. As shown in FIG.

  The 1st attachment part 32 is a site | part fixed to the bottom part 22 of the side frame 20, and is flat form, Comprising: One or more attachment holes are formed. The second attachment portion 33 is a portion fixed to the bottom portion 52 of the tunnel side frame 50, has a flat plate shape, and has one or more attachment holes. The connecting portion 34 is a portion located below the tunnel structure portion 13 and has a flat plate shape and has a substantially straight shape extending in the vehicle width direction in plan view.

  The pair of protection portions 31 are connected to the connecting portions 34 so that the protection members 30 are attached to the side frames 20 and the tunnel side frames 50 and become rearward of the vehicle body as they move outward in the vehicle width direction in plan view. Inclined and extended. In this embodiment, the width dimension of the protection part 31 is larger than the width dimension of the connection part 34, but the width dimension of the protection part 31 may be equal to or less than the width dimension of the connection part 34. Here, the width dimension refers to a dimension in the width direction of the protection member 30 (a direction orthogonal to the length direction of the protection member 30 (that is, the vehicle width direction)).

  The protection member 30 is fixed to the bottom portion 22 of the pair of side frames 20 and the bottom portion 52 of the pair of tunnel side frames 50 located on both sides of the rear end portion of the tunnel structure portion 13. Specifically, the pair of first attachment portions 32 are provided at the rear ends of the pair of front side frames 23 and / or the front ends of the pair of rear side frames 24, and the pair of second attachment portions 33 are provided at the pair of tunnel side frames 50. It is fixed to the rear end by using fixing means such as bolts 55 and nuts corresponding to the mounting holes. The second attachment portion 33 is located in front of the vehicle body relative to the first attachment portion 32, and the pair of protection portions 31 are separated from the front floor panel 11, and both ends are directed in the vehicle width direction toward the rear of the vehicle body in plan view. It has an almost square shape that spreads out.

  As shown in FIGS. 2 and 3, the protection portion 31, the protection member 30, and the lower surface 11 a of the front floor panel 11, and the connection portion 34 and the lower surface 11 a of the front floor panel 11 (that is, the tunnel structure portion 13). A ventilation space S is formed between the lower surface and the lower surface. The upper end edge 31 a of the protection part 31 is located above the lower surface 41 of the fuel tank 40, and the lower end edge 31 b is located below the lower surface 41.

  As shown in FIG. 5, the cross section (vertical cross section) of the protection part 31 in the front-back direction of the vehicle body has a shape that suppresses the air resistance of the traveling wind. In the present embodiment, the protection part 31 has a hollow vertical cross-sectional shape, and includes an upper part 35 that forms the upper surface thereof and a lower part 36 that forms the lower surface thereof. They are joined to each other at the rear end. The lower surface of the protection part 31 has an inclined surface 36a that extends obliquely downward toward the rear and an upright surface 36b that extends upward substantially perpendicularly from the lower end edge of the inclined surface 36a. It is preferable to form a flat surface with little protrusion in the front-rear direction). In the longitudinal section, the length of the lower portion 36 is longer than the length of the upper portion 35 as the peripheral length of the protective portion 31.

  In addition, as described above, the first mounting portion 32, the second mounting portion 33, and the connecting portion 34 have a flat plate shape, and the vertical cross section has a linear cross sectional shape with low air resistance (see FIG. 2). In addition, the plate | board thickness of the upper part 35 and the lower part 36 which comprise the 1st attachment part 32, the 2nd attachment part 33, the connection part 34, and the protection part 31 can be set suitably. In the present embodiment, the plate thickness of the first mounting portion 32, the second mounting portion 33, and the connecting portion 34 constitutes the protective portion 31 from the viewpoint of the vehicle body rigidity and the like of the lower part of the vehicle including the side frame 20 and the tunnel side frame 50. For example, the plate thicknesses of the upper portion 35 and the lower portion 36 are made larger than the plate thicknesses of the first mounting portion 32, the second mounting portion 33, and the connecting portion 34. Thus, the rigidity of the protection part 31 may be increased.

  In addition, the cross-sectional shape of the protection member 30 is not limited to this, and may be any cross-sectional shape that can suppress the air resistance of the traveling wind. Here, the cross-sectional shape that can suppress the air resistance of the traveling wind is the cross-sectional shape that can suppress the air resistance of the protection member 30 itself due to the traveling wind and / or the turbulence of the traveling wind passing through the ventilation space S and the protection member 30. It refers to a cross-sectional shape that can suppress the turbulence of traveling wind passing below.

  As shown in FIG. 3, in the mounted state, the lower surface 41 of the fuel tank 40 is located below the lowermost surface of the floor panel (that is, the lower surface 11a of the front floor panel 11) by a distance L1, and the protective portion 31 The lower end edge (that is, the lower end edge of the protective member 30) 31b is located below the lower surface 41 of the fuel tank 40 by a distance L2. As described above, in the vehicle body structure in which the lower surface 41 of the fuel tank 40 protrudes downward from the lower surface of the floor panel 10, obstacles such as rocks are caused by obstacles such as rocks during the traveling. Although it is easy to hit the convex lower surface 41 b), an obstacle hits the lower surface 41 by providing the protective member 30 in front of the fuel tank 40 and lowering the lower end edge 31 b of the lower surface 41 of the fuel tank 40. Can be prevented, or the impact can be absorbed by the protective member 30.

  FIG. 6 is a cross-sectional view similar to FIG. 3, illustrating the flow of the traveling wind X. In the conventional protective member, as indicated by the phantom line, it extends downward from the lower surface 11a of the front floor panel 11 continuously. In such a protective member, when the protruding distance L1 of the fuel tank 40 with respect to the floor panel 10 is large, the protective member protrudes downward from the floor panel 10 in accordance with this, and the air resistance of the protective member itself increases. End up. Further, the traveling wind easily enters the gap R between the protective member and the fuel tank 40, and a vortex is generated in the gap R, resulting in a decrease in aerodynamic performance.

  On the other hand, the protection member 30 of the present embodiment is fixed to the side frame 20 and the tunnel side frame 50, is separated from the lower surface 11a of the front floor panel 11, and has a ventilation space S therebetween. By providing such a ventilation space S, even if the protrusion distance L1 of the fuel tank 40 with respect to the floor panel 10 is increased, the air resistance can be reduced and the aerodynamic performance can be improved. Further, since the traveling wind X that has passed through the ventilation space S is attracted to the traveling wind X that passes through the lower surface of the protective member 30 and flows downward of the fuel tank 40, the traveling wind X is behind the protective member 30 (that is, in the gap R). The generation of vortex is suppressed and aerodynamic performance is improved.

  Furthermore, since the protection member 30, in particular, the protection part 31 located below the ventilation space S has a cross-sectional shape that suppresses the air resistance of the traveling wind X, the aerodynamic performance can be further improved. Further, the pair of C-shaped protection portions 31 guides the traveling wind X to both sides of the vehicle body, the inflow into the tunnel structure 13 is suppressed, and the traveling wind X contacting the fuel tank 40 is reduced to reduce the air. Resistance can be reduced.

  FIG. 7 is an enlarged view of a main part of FIG. 2, and shows a fixed state of the side frame 20 and the tunnel side frame 50 and the protection member 30. By fixing the protection member 30 to both the bottom portion 22 of the side frame 20 and the bottom portions 52 of the pair of tunnel side frames 50, relative movement between the side frame 20 and the tunnel side frame 50 can be suppressed. Further, the protection member 30 can suppress the twisting of the side frame 20 and the tunnel side frame 50, and the rigidity of the entire vehicle body is improved. As a result, it is possible to reduce vehicle floor vibration caused by vibration of the side frame 20 and the tunnel side frame 50.

  FIG. 8 is an enlarged view of a main part of FIG. 2 and shows a fixed state between the pair of tunnel side frames 50 and the protection member 30. Since the protection member 30 is fixed to the pair of tunnel side frames 50 located on both sides of the tunnel structure portion 13, it prevents the tunnel structure portion 13 from opening in the width direction (moving in the arrow direction in FIG. 8). Can do. In particular, the rear end portion of the tunnel structure portion 13 is easily affected by the bending of the floor panel 10, and its side wall is easy to open in the width direction, but the protective member 30 is connected to the tunnel side frames 50 on both sides of the rear end portion. By fixing to the side frame 20, the opening in the width direction can be effectively prevented.

  FIG. 9 is a perspective view of the vehicle body structure 2 according to the second embodiment of the present invention as viewed from the lower surface side. In the second embodiment, the same reference numerals as those in the first embodiment denote the same components, and the details thereof are omitted here.

  In this embodiment, the protection member 70 does not have the connection part 34, and consists of a pair of left and right members 71 and 72 in which the pair of protection parts 31 are separated from each other. The pair of members 71 and 72 are respectively positioned at one end (one end of the members 71 and 72 and both ends of the protective member 70) and fixed to the side frame 20 and the other. The second mounting portion 33 is fixed to the tunnel side frame 50, and the protection portion 31 is positioned between the first mounting portion 32 and the second mounting portion 33. With such a protective member 70, the aerodynamic performance can be further improved by eliminating the air resistance of the protective member 70 below the tunnel structure portion 13.

  In addition, this invention is not limited to embodiment mentioned above, A various change is possible in the range which does not deviate from the meaning of invention. For example, in this embodiment, the protective members 30 and 70 have a pair of protective portions 31 to protect the saddle-shaped fuel tank 40. However, when the fuel tank is a substantially rectangular parallelepiped type, the protective member May be any structure as long as it can protect the lower surface of the fuel tank and includes at least one protective part spaced from the floor panel.

DESCRIPTION OF SYMBOLS 10 Floor panel 13 Tunnel structure part 20 Side frame 30,70 Protection member 31 Protection part 31b Bottom edge of protection part 40 Fuel tank 41 Lower surface of fuel tank 50 Tunnel side frame

Claims (5)

A pair of left and right side frames located below the floor panel and extending in the longitudinal direction of the vehicle body;
A vehicle body structure comprising: a protective member that is disposed in front of the vehicle body relative to the fuel tank disposed between the pair of side frames and has a lower end edge positioned below the lower surface of the fuel tank;
The floor panel has a tunnel structure that protrudes inward of the vehicle body at the center in the width direction,
The protective member is fixed to a pair of tunnel side frames provided on both sides of the tunnel structure portion and projecting downward and extending in the front-rear direction, and both ends thereof are fixed to the pair of side frames. The vehicle body structure is characterized in that it has a ventilation space apart from the floor panel. 2. The vehicle body structure according to claim 1 , wherein the protection member is fixed to the pair of side frames and the pair of tunnel side frames located on both sides of a rear end portion of the tunnel structure portion. The protective member is a vehicle body structure according to claim 1 or 2 both side portions wherein extending from the tunnel side frame to the rear side toward the side frame, characterized in that it is a form of a slanted roof when viewed . The protective member has one end according to any one of claims 1 to 3, characterized in that the other end is fixed to the side frame is composed of a pair of members which are fixed to the tunnel side frame Car body structure. The protective member is a vehicle body structure according to any one of claims 1 to 4, characterized in that suppresses sectional shape air resistance of traveling wind.

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