Vehicle floor structure

A vehicle floor structure including a floor panel which includes: a plurality of arc beads which are provided on a surface of the floor panel so as to be arranged in parallel with each other and to extend from a side sill inner toward a middle cross member while being bent; and a bracket which is provided in the vicinity of the side sill inner for fixing an auto part, wherein: at least one of the beads in the vicinity of the side sill inner is diverged and connected to the beads at a farther side with respect to the side sill inner; the bracket is fixed so as to cover the bead in the vicinity of the side sill inner; and a farther end portion of the bracket with respect to the side sill inner is fixed so as to straddle the diverged beads.

BACKGROUND OF THE INVENTION

Priority is claimed on Japanese Patent Application No. 2007-111559, filed on Apr. 20, 2007, the content of which is incorporated herein by reference.

1. Field of the Invention

The invention relates to a vehicle floor structure which is provided with beads, especially a vehicle floor structure which is suitable for mounting an auto part such as a seat or a battery.

2. Description of the Related Art

Conventionally known examples of a vehicle floor structure are provided with beads having a concave-convex surface, in which an intersection of a side sill and a cross member is assigned to a center of the beads arrangement (see, for example, Japanese Unexamined Patent Application, First Publication No. 2006-298076). With the beads, rigidity of a floor panel can remarkably be enhanced while preventing the vehicle body weight from increasing.

According to the above-described conventional technology, although the rigidity of the floor panel can be enhanced due to the beads provided on the floor panel, there is a problem in that it is difficult for an auto part to be mounted on the floor surface because the beads are provided on the surface which is not flat.

In contrast, although it is possible to omit a bead where the auto-part is mounted, there is a problem in that the rigidity of the area where the bead is omitted is deteriorated.

In view of the above-described circumstances, the present invention has an object of providing a vehicle floor structure which can ensure effects of rigidity enhancement of a floor panel itself and the rigidity enhancement for a side vehicular collision due to the presence of beads, while enabling easy mounting of an auto part in the case where the floor panel is provided with the beads.

SUMMARY OF THE INVENTION

In order to achieve the aforementioned object, the present invention employs the following. Namely, the present invention employs a vehicle floor structure including a floor panel which includes: a plurality of arc beads which are provided on a surface of the floor panel so as to be arranged in parallel with each other and to extend from a side sill inner toward a middle cross member while being bent; and a bracket which is provided in the vicinity of the side sill inner for fixing an auto part, wherein: at least one of the beads in the vicinity of the side sill inner is diverged and connected to the beads at a farther side with respect to the side sill inner; the bracket is fixed so as to cover the bead in the vicinity of the side sill inner; and a farther end portion of the bracket with respect to the side sill inner is fixed so as to straddle the diverged beads.

According to the above-described vehicle floor structure, the rigidity of the floor panel can be enhanced since a decrease of the number of beads at a vicinity of the side sill inner compared to those at a farther side from the side sill inner is complemented with the bracket. As a result, it is possible to bear and transmit a collision load applied from the side sill inner reliably.

It may be arranged such that ridgelines of the bracket are respectively continued into outside ridgelines of the diverged beads.

In this case, it is possible to bear a collision load with two lines, that is, each ridgeline of the beads and the bracket when the load is applied at the time of a side vehicular collision. As a result, the collision load can be transmitted efficiently and reliably.

The present invention also employs a vehicle floor structure including a floor panel which includes: a plurality of arc beads which are provided on a surface of the floor panel so as to be arranged in parallel with each other and to extend from a side sill inner toward a middle cross member while being bent; and a bracket which is provided in the vicinity of the side sill inner for fixing an auto part, wherein: at least one of the beads has a single-stream bead portion which extends from the side sill inner and a double-stream portion which is formed by bifurcating a closer end portion of the single-stream bead portion with respect to the middle cross member, and continuously extends toward the middle cross member; the single-stream bead portion is covered with the bracket; each of a foot portion of the bracket is joined to a valley portion of the single-stream bead portion; and ridgelines of a closer end portion of the bracket with respect to the middle cross member are respectively continued into outside ridgelines of the double-stream bead portion.

According to the above-described vehicle floor structure, the bracket and the beads are subjected to a collision load applied to the side sill inner at a single-stream portion, and then some portion of the collision load is directly transmitted from the single-stream portion to a double-stream portion, while others are transmitted from the ridgeline of the bracket to the outside ridgelines of the double-stream portion. Those divided collision loads are summed up and transmitted to the middle cross member. As a result, the rigidity of the floor panel, which itself is reduced for mounting the bracket, is enhanced with the effective use of the bracket.

DETAILED DESCRIPTION OF THE INVENTION

An embodiment of the present invention will be described below with reference to the drawings. As shown inFIG. 1andFIG. 2, in a floor1of a vehicle, a floor tunnel frame2extending in the longitudinal direction of the vehicle body is formed along a central portion in the vehicle width direction. To both edges of this floor tunnel frame2, there are joined inside edges of left and right floor panels3,4. To outside edges of the left and right floor panels3,4, there are fixed left and right side sills5,6, which are vehicular frame members extending in the longitudinal direction of the vehicle body. That is, the left and right floor panels3,4are bridged respectively between the floor tunnel frame2and the left and right side sills5,6. Rear portions of the left and right side sills5,6are connected to each other by means of a middle cross member7which is a vehicular frame member arranged in the vehicle width direction. A front edge portion of the middle cross member7is joined to rear edges of the left and right floor panels3,4. Furthermore, a substantially central portion in the longitudinal direction of the floor tunnel frame2is connected to the left and right side sills5,6by means of left and right front cross members9,10arranged in the vehicle width direction, respectively.

On the other hand, to walls of both sides of a front end portion of the floor tunnel frame2, there are respectively joined one of each end of extensions11,12. To front end portions of the left and right side sills5,6, there are respectively joined one of each end of outriggers13,14. These left and right extensions11,12are respectively connected to inside walls of the outriggers13,14. Left and right end portions47,47of the middle cross member7are bent in an obliquely forward direction. To rear walls of these left and right end portions47,47and to rear inner walls of the left and right side sills5,6, there are connected front end portions of left and right rear side frames15,16. The floor panels3,4and the floor tunnel frame2are main components of the floor1.

The left and right extensions11,12and the outriggers13,14which are constructed in this manner function as lateral frame members in that they connect the side sills5,6with the floor tunnel frame2in the vehicle width direction.

As shown inFIG. 3, the floor tunnel frame2is made of a tunnel main body19and wing portions21,21. The tunnel main body19is made of a top wall17and two inclined side walls18,18so as to form a convex above floor panels3,4. Wing portions21,21extend outwardly from bottom ends of both the inclined side walls of the tunnel main body19extending below surfaces of the left and right floor panels3,4, and respectively welded onto bottom surfaces of the floor panels3,4in flange portions20. On the inside edges of the left and right floor panels3,4, there are respectively formed flange portions22in a rising manner. These flange portions22are welded onto both the side walls18,18of the tunnel main body19of the floor tunnel frame2.

That is, outside both the side walls18,18of the floor tunnel frame2, and below the floor panels3,4, there are formed closed section structures H1formed of the wing portions21,21of the floor tunnel frame2and the floor panels3,4.

Each of the side sills5,6is made of: a side sill inner23formed in a convex shape on the vehicle interior side, that is, in a U-shaped cross-section opening toward the outside; a reinforcement25; and a side sill outer8. The reinforcement25has a U-shaped cross-section opening toward the inside and is joined to the side sill inner23in top and bottom joint flange portions24,24to form a closed section structure. The side sill outer8is joined to the joint flange portions24to form a closed section structure outside the reinforcement25. The side sill inner23is formed in a linear shape with the same cross-section over substantially all the length. On the other hand, as shown inFIG. 1andFIG. 2, the reinforcement25is made of a front inclined wall25F and a rear inclined wall25R which have a more outwardly protruding dimension as they extend respectively from the front and rear ends to the center in the longitudinal direction. These front inclined wall25F and rear inclined wall25R form inclined closed section structures HF2, HR2. A maximally protruded, closed section structure H2in the reinforcement25whose protruding dimension to the outside is maximum is formed over a predetermined length in the longitudinal direction of the vehicle body. The maximally protruded, closed section structures H2are arranged between the middle cross member7and the front cross members9,10. To inside walls26of the side sill inners23, there are respectively joined flange portions27which are formed at outside edges of the left and right floor panels3,4in a rising manner.

As shown inFIG. 4, the middle cross member7is formed of two opposingly arranged members with substantially an L-shaped cross-section, in which rear top edge flange portions28of the members are welded onto opposing front bottom edge flange portions29of the members, respectively. This middle cross member7forms a closed section structure H3with a substantially rectangular shape, which functions as a vehicle body frame portion, on the top surfaces of the floor panels3,4. The front bottom edge flange portions29are respectively welded onto the rear edges of the left and right floor panels3,4. To a rear wall30, there are joined front end portions of the left and right rear side frames15,16.

The front cross members9,10are members with a hat-shaped cross section opening downwardly. Flange portions31,31at the front and rear of the front cross members9,10are respectively joined to top surfaces of the left and right floor panels3,4. As a result, closed section structures H4are formed as a vehicle body frame portion along the vehicle width direction on the top surfaces of the floor panels3,4. Outside ends of the front cross members9,10are joined to side walls26which include top walls of the side sill inners23. On the other hand, in inside ends of the front cross members9,10, as shown inFIG. 1andFIG. 2, a front flange portion32and a rear flange portion33thereof are joined to an outer surface of the side wall18of the floor tunnel frame2. Furthermore, end edges of top walls34of the front cross members9,10are joined to the top wall17of the floor tunnel frame2.

Here, as shown inFIG. 1 through 3, on a backside of the tunnel main body19of the floor tunnel frame2, a joint frame35is joined to positions at which the left and right cross members9,10are connected. This joint frame35has a hat-shaped cross section that opens upwardly, opposite to the case of the front cross members9,10. A bottom wall36of the joint frame35is aligned with the surfaces of the floor panels3,4. A front side flange37and rear side flange38(seeFIG. 1andFIG. 2) of the joint frame35are joined to the backside of the tunnel main body19. Both of end edges39,39of the bottom wall36are joined to the backside of the tunnel main body19of the floor tunnel frame2. Note that the left and right front cross members9,10are omitted inFIG. 3.

As a result, a closed section structure H5is formed between the joint frame35and the floor tunnel frame2. This closed section structure H5connects with each of the closed section structures H4formed between the left and right front cross members9,10and the floor panels3,4, to thereby form a substantially continuous vehicle frame member which connects the side sills5,6along the vehicle width direction.

As shown inFIG. 5, one of each end of the left and right extensions11,12is formed in a shape which opens upwardly so as to cover the entire surface of the wing portion21of the floor tunnel frame2from below. Top ends of inside walls40of the left and right extensions11,12are positioned substantially at the same height as those of the flange portions22of the floor panels3,4. The top ends thereof are joined to back surfaces of the side walls18of the tunnel main body19of the floor tunnel frame2. Flange portions41on the outside of the other ends of the extensions11,12are joined to the flange portions20of the wing portions21.

The outriggers13,14respectively include: a bottom wall43joined to a bottom wall42of the respective side sill inners23,23; and a rising flange portion44joined to the bottom surface of the respective floor panels3,4. As a result, the outriggers13,14form closed section structures H6respectively between the side sills5,6and the floor panels3,4.

As shown with a double-dotted chain line inFIG. 4, front end portions of the extensions11,12and the outriggers13,14are formed so as to gradually rise forward along a backside surface of a dashboard panel45joined to top surfaces of front edges of the floor panels3,4. As shown inFIG. 6andFIG. 7, to the bottom walls43of the outriggers13,14whose front side is formed in a hat-shaped cross section, there are respectively joined bottom walls46of the extensions11,12, and thereby these two are connected.

To a front end of the outrigger13, there is connected a rear end of a front side frame (not shown in the figure). Note that the double-dotted chain line inFIG. 6andFIG. 7shows the dashboard panel45which forms the closed section structures H6respectively between the outriggers13,14and itself, and also forms the closed section structures H1respectively between the outriggers13,14as well as the extensions11,12and itself.

As shown inFIG. 1andFIG. 2, on the floor panels3,4, there are regularly provided a plurality of wave-formed beads50over substantially the entire surface thereof and also provided a plurality of drain holes51and a plurality of positioning holes52. The floor panels3,4are formed in a laterally symmetrical manner with respect to the floor tunnel frame2. Furthermore, the beads50, drain holes51, and positioning holes52formed respectively on the floor panels3,4are arranged in a laterally symmetrical manner with respect to the floor tunnel frame2. Hereunder is a detailed description only of the left floor panel3. As for the right floor panel, like parts are designated with like reference numerals, and the description thereof is omitted. In the cross-sectional views ofFIG. 3toFIG. 5, a cross-sectional shape of the bead50, which is a complicated shape, is shown as a simple shape for convenience of illustration in the figures.

In the floor panel3, the forward part and the backward part across the front cross member9are different from each other in the arrangement pattern of the beads50.

A region S1in the floor panel3which is surrounded by the floor tunnel frame2, the front cross member9, the extension11, and the outrigger13has a plurality of the beads50provided in a concentric arc-shaped manner at regular intervals, with the center at an intersection X1of a center of the cross-section of one end of the outrigger13and the inside wall26of the side sill inner23. One of each end of the beads50extends, starting orthogonally to the inside wall26of the side sill inner23. Some of the other ends of the beads50extend so as to be orthogonal to a width direction of the front side frame connected to the outrigger13.

On the other hand, a region S2in the floor panel3which is surrounded by the floor tunnel frame2, the front cross member9, and the middle cross member7has a plurality of beads50provided in a concentric arc-shaped manner at regular intervals, with the center at an intersection X2of a center of the cross-section at an end portion on the left side of the middle cross member7and the inside wall26of the side sill inner23. One of each end of the beads50extends, starting orthogonally to the inside wall26of the side sill inner23. The other ends of the beads50extend so as to be orthogonal to the longitudinal direction of the middle cross member7. The bead50is formed by stamping into a trapezoidal shape protruding above a general surface. Between the adjacent beads50,50, there is formed a valley portion53.

A plurality of beads50provided in this manner enhance the rigidity of the floor panels3,4.

Furthermore, in the forward region S1further forward than the front cross member9, the drain holes51and the positioning hole52are arranged on a diagonal line from a joint portion between the outrigger13and the side sill inner23to a joint portion between the floor tunnel frame2and the front cross member9. On the other hand, in the backward region S2further backward than the front cross member9, the drain holes51and the positioning hole52are arranged on a diagonal line from a joint portion between the front tunnel frame2and the front cross member9to a joint point between the middle cross member7and the side sill inner23.

A single drain hole51is provided at the center of every valley portion53between the adjacent beads50. These drain holes51are for draining electrodeposition solution from the floor panel3when the floor panel3is taken out of the electrodeposition solution pool in the electrodeposition process for the floor panel3.

A single positioning hole52is provided in each of the regions S1, S2in the front and at the back of the front cross member9in the floor panel3. Each of the positioning holes52is provided at a portion where the peaks of the two adjacent beads50,50are combined.

As shown inFIG. 8, in the region S2which is surrounded by the floor tunnel frame2, the front cross member9, and the middle cross member7, an outside bracket60and an inside bracket61are fixed to the floor panel3for supporting a seat (not shown in the figure).

The inside bracket61, which is a plate-like member formed in a rectangular shape, is joined to a face of the floor panel3where the beads50are not provided, more specifically, a place which corresponds to the wing portion21of the floor tunnel frame2. A mounting slot63in which a weld nut62is disposed is formed at the back side of the inside bracket61.

On the other hand, the outside bracket60is fixed to a position further backward and outward than the positioning hole52.

More specifically, as shown inFIG. 9 through 12, the outside bracket60is fixed to where the beads50are formed. Because of this, an unique structure for installation is adopted for the outside bracket60. The floor panel3to which the outside bracket60is fixed is provided with a plurality of the beads50, one of each end of which extends from the side sill inner23so as to be orthogonal thereto. A single stream bead portion50A is provided where the outside bracket60is fixed, so as to extend from the side sill inner23. At a farther end portion of the single-stream bead portion50A with respect to the side sill inner23, which is closer to the center of the vehicle, double-stream bead portions50B,50B are formed such that the farther end portion of the single-stream bead portion50A is continuously bifurcated into the double-stream bead portions50B,50B. Note that the single-stream bead portion50A and the double-stream bead portions50B,50B are constructed in the same manner as the other beads50, except for the bifurcation, since the specific reference numerals are assigned to the single-stream bead portion50A and the double-stream bead portions50B,50B for differentiation. Also note that the number of beads in the vicinity of the side sill inner23is less than that at the farther side therefrom because of the bifurcation structure as mentioned above.

The single-stream bead portion50A has a larger cross section compared to the other normal beads as shown inFIG. 10, specifically the width dimension L of its valley portion53is wider than that of the other normal beads50.

The outside bracket60is provided so as to cover the single-stream bead portion50A from the above. Beside that, the farther end portion of the outside bracket60with respect to the side sill inner23straddles the double-stream bead portions50B,50B.

On the backside surface of a top wall portion65of the outside bracket60, there is provided the weld nut62, which constitutes the mounting slot for a seat.

The outside bracket60includes a front inclined wall66and a rear inclined wall67at the front edge and the rear edge of the top wall portion65, respectively. On the front inclined wall66and the rear inclined wall67, there are horizontally formed foot portions68,68, respectively. Each of the foot portions68,68is joined to the valley portion53of the single-stream bead portion50A by spot welding.

As shown inFIG. 12, a flange portion69is formed so as to extend vertically from the near end of the outside bracket60with respect to the side sill inner23. The flange portion69is positioned at each edge of the floor panel3, and is joined to the flange portion27which is joined to the side sill inner23.

At the farther end portion of the top wall portion65of the outside bracket60with respect to the side sill inner23, there is provided an inclined portion71which is inclined toward top walls70,70of the double-stream bead portions50B,50B. On the front edge and the rear edge of the inclined portion71, there are respectively formed a front inclined portion72and a rear inclined portion73which are slightly bent. On the front inclined portion72and the rear inclined portion73, there are respectively formed a front foot portion74and a rear foot portion75. The front foot portion74and the rear foot portion75are respectively joined to the outer valley portions53,53of the double-stream bead portion by spot welding. Here, the farther side edge of the inclined portion71with respect to the side sill inner23is aligned with the top walls70,70of the double-stream bead portions50B,50B. A ridgeline R1between the inclined portion71and the front inclined portion72and another ridge line R1between the inclined portion71and the rear inclined portion73are formed so as to respectively continue into outside ridgelines R2, R2of the double-stream bead portions50B,50B.

Here, the end of the ridgeline R1between the inclined portion71and the rear inclined portion73and one of the ridgelines R2, R2of the double-stream bead portions50B,50B are joined by MIG welding. Similarly, the end of the ridgeline R1between the inclined portion71and the front inclined portion72and the other ridgeline R2of the double-stream bead portions50B,50B are joined by MIG welding.

According to the above-described embodiment, as shown inFIG. 9 and 12, when a collision load (shown as an arrow F0in the figures) is applied to the side sill5at the time of a side vehicular collision, the collision load F0acts on the floor panel3from the side sill inner23via the flange portion27. Some portion of the collision load F0which is applied from the flange portion27of the floor panel3acts on the single-stream bead portion50A toward the vehicle interior side as a load FA, and then the load FA is transmitted from the single-stream bead portion50A to the double-stream bead portions50B,50B into which the bifurcated end of the single-stream bead portion50A continues. For this reason, since the applied load is dispersed on each of the double-stream bead portions50B,50B, the floor structure of the present invention is advantageous in this regard.

On the other hand, the other portion of the collision load F0acts on the outside bracket60from the flange portion27, and is transmitted to the front inclined portion72and the rear inclined portion73via the top wall portion65, the inclined portion71, the front inclined wall66and the rear inclined wall67, and is further transmitted as two separate loads FB to the double-stream bead portions50B,50B, in which the ridgelines R1, R1of the outside bracket60are respectively aligned with the outside ridgelines R2of the double-stream bead portions50B,50B.

According to the above-described structure, it is possible to reinforce the floor panel3with the outside bracket60despite the single-stream bead portion50A being provided on the floor panel3with a reduced number of beads. More specifically, since the single-stream bead portion50A and the outside bracket60can bear a collision load, the rigidity of the floor panel3can be enhanced. As a result, with the above-described structure, it is possible to bear and transmit the collision load F0which is applied to the side sill inner23at the time of a side vehicular collision.

More specifically, when the collision load F0which is applied to the side sill inner23acts on the beads50, the single-stream bead portion50A and the outside bracket60bear the load at the area where the single-stream bead portion50A is provided, and then some portion of the load is directly transmitted from the single-stream portion50A to the double-stream bead portions50B,50B, and the other portion of the load is transmitted from the ridgelines R1, R1of the outside bracket60to the outside ridgelines R2, R2of the double-stream bead portions50B,50B, respectively. Finally those divided loads are summed up and transmitted to the middle cross member7via the double-stream bead portions50B,50B. As a result, with the effective use of the bracket, it is possible not only to enhance the rigidity of the floor panel3which undergoes deterioration of the rigidity due to the limitation of the beads arrangement for fixing the outside bracket60, but also to enhance the transmission efficiency of the collision load.

As has been described above, the present invention enables the effects of the rigidity enhancement of the floor panels3,4and the rigidity enhancement for a side vehicular collision due to the presence of the beads50to be ensured, while enabling easy mount of an auto part such as a seat in the case where the floor panels3,4are provided with the beads50.

Note that the present invention is not limited to the above-described embodiment. In the above-described embodiment, the bracket for mounting a seat has been explained, but the bracket can be applicable for mounting a battery to drive an electric vehicle or a hybrid vehicle. In addition, the cross section of each bead is a trapezoidal shape in the embodiment, but the cross section can be a semicircular or triangle shape. Furthermore, the single-stream bead portion is bifurcated to continuously form the double-stream portion, but the single-stream bead portion can be divided into three streams or more.

While a preferred embodiment of the invention has been described and illustrated above, it should be understood that this is exemplary of the invention and is not to be considered as limiting. Additions, omissions, substitutions, and other modifications can be made without departing from the spirit or scope of the present invention. Accordingly, the invention is not to be considered as being limited by the foregoing description, and is only limited by the scope of the appended claims.