Vehicle body floor structure

Vehicle body floor structure has a floor tunnel provided on a laterally central portion of a vehicle body floor panel and extending in a front-rear direction of a vehicle body, a desired stored component being stored in the floor tunnel. The stored component has a passageway formed therein to extend in a width direction of the vehicle body. The floor structure also has a cross member passed through the passageway of the stored component, the stored component is supported on the cross member via a resilient member, and the cross member is fixedly fastened at its opposite ends to the inner surfaces of opposed side walls of the floor tunnel.

FIELD OF THE INVENTION

The present invention relates to vehicle body floor structures having a floor tunnel that accommodates or stores a functional component, such as a fuel tank or a fuel cell stack.

BACKGROUND OF THE INVENTION

Heretofore, various anti-collision measures or techniques have been proposed for body floor structures of vehicles, particularly automotive vehicles. For example, vehicles are known in which a cross member is additionally provided in a floor tunnel in order to minimize or suppress deformation of the vehicle at the time of a lateral or side collision. Also known is a vehicle body floor structure constructed to disperse a load, produced by a lateral collision, across the entire vehicle using a seat structure. Examples of such a vehicle body floor structure are disclosed in Japanese Patent Application Laid-Open Publication No. H09-136575 (hereinafter referred to as “patent literature 1”) and Japanese Patent Application Laid-Open Publication No. 2005-67427 (hereinafter referred to as “patent literature 2”), where a load applied from a side of the vehicle body is transmitted into a center console or transmitted to the upper surface of the floor tunnel.

In the vehicle body floor structure disclosed in patent literature 1, two hollow beams span between opposed side walls of the center console and are located at positions corresponding to the backs of front seats, so that a load applied from a side of the vehicle body can be transmitted into the center console.

In the vehicle body floor structure disclosed in patent literature 2, left and right side sills are provided on left and right sides of the vehicle body and extend in a front-rear direction of the vehicle body, and a floor tunnel provided on a laterally central portion of the vehicle body and extends in parallel to the left and right side sills. Further, left and right seats are disposed with the floor tunnel interposed therebetween, and a left cross member is provided under the left seat and connecting between the left side sill and the floor tunnel while a right cross member is provided under the right seat and connecting between the right side sill and the floor tunnel.

FIG. 5hereof shows a conventionally-known vehicle body floor structure200, in which a tunnel cross member202is provided within a floor tunnel201so as to minimize deformation of the vehicle body due to a load transmitted from a side sill203to the floor tunnel201via a seat cross member204. Further, a load produced by a side collision can be dispersed across the entire vehicle body using the construction of the seat205.

Environment-friendly vehicles have come to the front in recent years, but these vehicles are more complicated in structure than ordinary vehicles. Further, equipment mounted on the environment-friendly vehicles tends to be great in size.

Thus, in another conventionally-known vehicle body floor structure210shown inFIG. 6, a functional component212is sometimes mounted within a floor tunnel211. Among examples of the functional component212are a high-voltage electrical system for a hybrid vehicle, a fuel tank of an internal combustion engine, a battery of an electric vehicle, etc. The functional component212is supported in the floor tunnel211by means of a sub chassis213. However, in the case where the functional component212is mounted within the floor tunnel211, a load caused by a side collision (i.e., side collision load) must be prevented from being transmitted to the floor tunnel211, with a view to protecting the functional component212from the side collision load.

Thus, in still another conventionally-known vehicle body floor structure220shown inFIG. 7, a functional component222is constructed to have a relatively great strength and mounted on a sub chassis223that is in turn fixed to a floor tunnel221. Thus, a load caused by a side collision can be safely transmitted to the floor tunnel221. However, in this case, the functional component222itself tends to be great in weight, which would lead to an increased overall weight of the vehicle body.

Thus, in still another conventionally-known vehicle body floor structure230shown inFIG. 8, functional components232are fixed to a partition wall234without being constructed to have a particularly great strength, and these functional components232and partition wall234are mounted on a sub chassis233that is in turn fixed to a floor tunnel231. However, when a load has been applied from a side of the vehicle body, the functional components232fixed to the partition wall234may also be undesirably dragged so that there would occur a possibility of the functions of the components232being impaired.

Namely, even in the case where a functional component is disposed within the floor tunnel provided on a laterally central portion of the vehicle body, it is desirable that arrangements be made for dispersedly transmitting a load caused by a side collision of the vehicle and preventing the collision load from acting on the functional component provided within the floor tunnel.

SUMMARY OF THE INVENTION

In view of the foregoing prior art problems, it is an object of the present invention to provide an improved vehicle body floor structure which can reliably protect a functional component, disposed within a floor tunnel provided on a laterally central portion of the vehicle body, from an external input force, such as a load caused by a side collision of the vehicle, and can effectively disperse such an external input force.

In order to accomplish the above-mentioned object, the present invention provides an improved vehicle body floor structure, which comprises: a floor tunnel provided on a laterally central portion of a vehicle body floor panel and extending in a front-rear direction of a vehicle body, a stored component being stored in the floor tunnel, the stored component having a passageway formed therein to extend in a width direction of the vehicle body; and a cross member passed through the passageway of the stored component, the stored component being supported on the cross member via a resilient member, the cross member being fixed at opposite ends thereof to the inner surfaces of opposed side walls of the floor tunnel.

The passageway extending through the stored component in the width direction of the vehicle body may be changed in position in the front-rear direction of the vehicle body so that the cross member can be placed or set at a desired position. In this way, the cross member can be set at a suitable position (load input position) to which a load applied from a side of the vehicle can be efficiently transmitted. As a consequence, the present invention can eliminate a need to increase reinforcement of the vehicle body and thereby reduce the weight of the vehicle body.

Further, because the stored component is supported in a substantially floating manner within the floor tunnel by being supported on the cross member via the resilient member, an assembly error can be effectively absorbed, which can thereby facilitate positioning of the cross member relative to the inner surfaces of the opposed side walls of the floor tunnel at the time of assembly. In addition, when a side collision load is input to the cross member, the side collision load can be effectively prevented from acting on the stored component that is supported in a substantially floating manner within the floor tunnel.

Preferably, the stored component is a functional component having a fuel storage function, power generating function or electric power storage function, or a high-voltage electric system. Namely, because the stored component is supported in a substantially floating manner within the floor tunnel by being supported on the cross member via the resilient member as noted above, a functional component having a fuel storage function, power generating function or electric power storage function, or a high-voltage electric system can be stored as the stored component within the floor tunnel.

The stored component may be a fuel cell stack that tends to cause vibrations and noise during generation of electric power. However, because the stored component is supported in a substantially floating manner within the floor tunnel by being supported on the cross member via the resilient member as noted above, vibrations and noise are hardly transmitted to the floor tunnel, so that noise within a passenger compartment can be minimized. The stored component may be a fuel tank.

Preferably, the cross member supports the stored component via a stay member that is supported, via the resilient member, in a substantially floating manner within the floor tunnel. Thus, the stored component can be mounted (sub-assembled) to the cross member in advance, which allows the cross member and stored component to be assembled to the vehicle body with an increased ease.

Preferably, the cross member is fixed at the opposite ends to horizontal bracket bottom surfaces each projecting in a substantially right-angled triangular shape from the inner surface of a corresponding one of the opposed side walls of the floor tunnel. Thus, the cross member can be fixedly fastened to the floor tunnel from below, which can significantly enhance mounting operability of the cross member.

Preferably, the stay member is provided in perpendicularly intersecting relation to the cross member. This arrangement can stably support the stored component that is, for example, elongated in the front-rear direction of the vehicle body. Alternatively, the stay member may be provided in parallel relation to the cross member.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1is an exploded perspective view of an embodiment of a vehicle body floor structure of the present invention, andFIG. 2is a sectional front view of the vehicle body floor structure shown inFIG. 1. The vehicle body floor structure shown inFIGS. 1 and 2includes: a floor panel13defining a bottom section of a passenger compartment; a floor tunnel14provided on a laterally central portion of the floor panel13and extending in a front-rear direction of the vehicle body; a sub chassis21fixed to the floor tunnel14; a stored component22mounted on the sub chassis21; front and rear retaining members23that retain front and rear end portions of the stored component22; a cross member25fixed to the floor tunnel14; and a stay member27mounted on the cross member25via a resilient member26for supporting the stored component22. Namely, the stay member27is supported, via the resilient member26, in a substantially floating manner within the floor tunnel14; thus, it can be said that the stored component22is supported in a substantially floating manner within the floor tunnel14by being supported on the cross member25via the stay member27and resilient member26.

The floor tunnel14has left and right brackets33on the inner surfaces31of its opposed left and right side walls, and the cross member25is fixed to the left and right brackets33. Each of the left and right brackets33has: front and rear projections35each projecting inwardly from the inner surface31of the left or right side wall; a horizontal bracket bottom surface37integrally formed with and extending between the lower end edges of the front and rear projections35so that one end portion of the cross member25is mounted on the horizontal bracket bottom surface37; and a vertical surface38welded to the inner surface31of the left or right side wall.

As viewed from the front of the floor tunnel14, each of the left and right brackets33projects in a right-angled triangular shape from the inner surface31of the left or right side wall. The horizontal bracket bottom surface37has bolt holes41into which bolts39are screwed.

The sub chassis21includes: left and right longitudinal members42and43extending in the front-rear direction of the vehicle body; a front cross member44connecting between the respective front ends of the left and right longitudinal members42and43; a rear cross member45connecting between the respective rear ends of the left and right longitudinal members42and43; and first and second intermediate cross members46and47connecting between respective intermediate portions of the left and right longitudinal members42and43.

Holes48for fixing the front retaining member23to the sub chassis21are formed in front end portions of the left and right longitudinal members42and43, and holes49for fixing the rear retaining member23to the sub chassis21are formed in rear end portions of the left and right longitudinal members42and43. Resilient cushion members51for resiliently supporting the stored component22are provided on the upper surfaces of the first and second intermediate cross members46and47. As shown, the sub chassis21has a rectangular shape elongated in the front-rear direction of the vehicle body.

The stored component22is a functional component having a fuel storage function, power generating function or electric power storage function, or a high-voltage electric system for a hybrid vehicle. More specifically, the functional component may be a fuel tank, a fuel cell stack or a battery; in the instant embodiment, the stored component22is a fuel cell stack.

The fuel cell stack22has a passageway53formed therethrough to extend in the width direction of the vehicle body, i.e. from one side surface52to another52. The cross member25is passed through the passageway53, and the stay member27is accommodated in the passageway53. Mounting portions54for mounting the stay member27to the fuel cell stack22are provided on the upper wall surface53aof the passageway53. The fuel cell stack22also has vertical through-passage portions55each extending from the upper surface22aof the fuel cell stack22down to one of the mounting portions54. Mounting screws56are inserted through the through-passage portions55to be screwed into the stay member27.

The front and rear retaining members23retain the fuel cell stack22in the front-rear direction of the vehicle body by sandwiching the fuel cell stack22in the front-rear direction. Each of the front and rear retaining members23has through-holes61formed in a lower end horizontal portion thereof and is fastened to left and right lower end horizontal portions of the floor tunnel14together with the sub chassis21by means of bolts62extending upwardly through the holes48or49and holes61to be screwed to nuts63(seeFIG. 2) welded to the upper surfaces of the left and right lower end horizontal portions of the floor tunnel14.

The cross member25includes a body section64passed through the passageway53of the fuel cell stack22. The body section64has left and right mounting sections65on its left and right ends for fixedly mounting to the left and right brackets33. Each of the mounting sections65has through-holes69for passage therethrough of the bolts39. The cross member25has a substantially “I” shape as viewed in plan.

The stay member27has screw holes66formed in front and rear end portions thereof, into which mounting screws56are screwed for fastening the fuel stack cell22. In the instant embodiment, the stay member27is provided in perpendicularly intersecting relation to the cross member25.

FIGS. 3A to 3Care views explanatory of an example manner in which a load is transmitted in the vehicle body floor structure shown inFIG. 1. At the time of a lateral or side collision, a collision load acts on a side sill16and seat17as indicated by a white arrow a1inFIG. 3A. The load having acted on the side sill16and seat17is then transmitted via the seat17toward the floor tunnel14as indicated by an arrow a2inFIG. 3B, but also transmitted via a seat cross member18toward the floor tunnel14as indicated by an arrow a3inFIG. 3B.

Then, the load transmitted via the seat17is transmitted via the upper surface14aof the floor tunnel14toward a side of the vehicle body as indicated beam arrow a4inFIG. 3C, while the load transmitted via the seat cross member18to the floor tunnel14is further transmitted via the cross member25to the side of the vehicle body as indicated by an arrow a5inFIG. 3C. Because the fuel cell stack22stored within the floor tunnel14is spaced, or substantially floating, from the sub chassis21and floor tunnel14via the resilient member26and the cushion member51, the collision load hardly acts on the fuel cell stack22.

In the vehicle body floor structure10, as described above in relation toFIGS. 1-3, the stored component22is stored within the floor tunnel14provided on a laterally central portion of the floor panel13of the vehicle body and extending in the front-rear direction of the vehicle body, and the cross member25is passed through the passageway53formed through the stored component22in the width direction of the vehicle body. Further, the stored component22is supported on the cross member25via the resilient member26, and the cross member25is fixedly connected at its opposite ends to the inner surfaces31of the left and right side walls of the floor tunnel14.

The passageway53extending through the stored component22in the width direction of the vehicle body may be changed in position in the front-rear direction of the vehicle body so that the cross member25can be set at a desired position. In this way, the cross member25can be set at a suitable position (load input position) to which a load applied from a side of the vehicle can be efficiently transmitted. As a consequence, the instant embodiment can eliminate a need to increase reinforcement of the vehicle body and thereby reduce the weight of the vehicle body.

Further, because the stored component22is supported in a substantially floating manner within the floor tunnel14by being supported on the cross member25via the resilient member26, no side collision load acts on the stored component22even when the side collision load is applied to the cross member25.

As described above, the stored component22is a functional component having a fuel storage function, power generating function or electric power storage function, or a high-voltage electric system, and the stored component22is supported in a substantially floating manner within the floor tunnel14by being supported on the cross member25via the resilient member26. Thus, a functional component having a fuel storage function, power generating function or electric power storage function, or a high-voltage electric system can be safely stored as the stored component within the floor tunnel14.

More specifically, in the described embodiment, the stored component22is a fuel cell stack22that tends to cause vibrations and noise during generation of electric power. However, because the fuel cell stack22is supported in a substantially floating manner within the floor tunnel14, vibrations and noise are hardly transmitted to the floor tunnel14, so that noise within the passenger compartment can be effectively minimized.

According to the instant embodiment, where the stored component22is supported on the cross member25in a substantially floating manner via the resilient member26and stay member27, the stored component22can be mounted (sub-assembled) to the cross member25in advance, which allows the cross member25and stored component22to be assembled together to the vehicle body with an increased ease.

Furthermore, because the cross member25is fastened or fixed to the horizontal bracket bottom surfaces37of the brackets33each projecting inwardly in a right-angled triangular shape from the corresponding inner surface31, it can be fixedly fastened to the floor tunnel14from below, which can significantly enhance mounting operability of the cross member25.

Furthermore, with the cross member25and the stay member27provided in perpendicularly intersecting relation to each other, the instant embodiment can stably support the stored component22that is, for example, elongated in the front-rear direction of the vehicle body.

FIG. 4is an exploded perspective view of a second embodiment of the vehicle body floor structure of the present invention. The second embodiment of the vehicle body floor structure100includes: a floor tunnel104provided on a laterally central portion of the floor panel (not shown in the figure) and extending in the front-rear direction of the vehicle body; left and right brackets113fixed to the inner surfaces111of opposed left and right side walls of the floor tunnel104and each projecting in a right-angled triangular shape from the inner surface111of the left or right side wall; an stored component102stored within the floor tunnel104; a cross member105passed through the stored component102in the width direction of the vehicle body and fixed to the left and right brackets113; and a stay member107that supports the stored component102.

Each of the left and right brackets113has: front and rear projections115each projecting inwardly from the inner surface111of the left or right side wall; a horizontal bracket bottom surface117integrally formed with and extending between the lower end edges of the front and rear projections115so that one end portion of the cross member105is mounted on the horizontal bracket bottom surface117; and a vertical surface118welded to the inner surface31of the left or right side wall.

Further, as viewed from the front of the floor tunnel104, each of the left and right brackets113projects in a right-angled triangular shape from the inner surface111of the left or right side wall. The horizontal bracket bottom surface117has nuts121welded thereto so that bolts119are screwed into the nuts121.

In this embodiment, the stored component102is a fuel tank for storing fuel. The fuel tank102has a passage way (opening)133for passage therethrough the cross member105and stay member107. The fuel tank102also includes left and right flanges134having through-holes137for passage therethrough bolts136.

The cross member105includes a body section144passed through the passageway of the fuel tank102, and left and right mounting sections145for fixedly mounting to the left and right brackets113. Furthermore, the cross member105has a substantially “I” shape as viewed in plan. The left and right mounting sections145each have through-holes149for passage therethrough the bolts119.

The stay member107has a stay body section147that is supported via a resilient member106, and mounting sections148bent from the opposite, i.e. left and right, ends of the stay body section147. Each of the flange sections148has a bolt hole146formed therein for passage therethrough a bolt136for mounting a corresponding one of the flanges134of the fuel tank102to the flange section148.

Further, in this embodiment, the stay member107is provided in parallel relation to the cross member105. The fuel tank102is stored within the floor tunnel104in a substantially floating manner by being supported on the resilient member106, and thus, a side collision load hardly acts on the fuel tank102as with the fuel cell stack22in the first embodiment of the vehicle body floor structure10.

Whereas the vehicle body floor structure of the present invention has been described above as having the passageway formed in the stored component and extending in the width direction of the vehicle body as shown inFIG. 1, the present invention is not so limited, and the passageway may be a recess.

Further, other resilient members may be interposed between the front and rear retaining members23and the stored component22ofFIG. 1.

The vehicle body floor structure of the present invention is well suited for application to passenger cars of a sedan type, wagon type, etc.