JP5818155B2 - Lower floor structure of the car body - Google Patents

Description

  The present invention relates to a floor lower structure of a vehicle body that is applied particularly to a small vehicle and absorbs an external load from the front of the vehicle.

  Generally, in a vehicle such as an automobile, the front end portion of the vehicle body may receive an external load from the front of the vehicle. For this reason, floor side members extending in the vehicle front-rear direction from the front end portion to the rear end portion of the vehicle body are provided on the left and right sides of the lower surface of the floor panel. It is configured to be able to absorb external loads from.

Patent Document 1 (Japanese Patent Laid-Open No. 2010-234939) has been proposed as an example of a lower structure of a vehicle body provided with a floor side member that absorbs an external load from the front of the vehicle.
FIG. 7 is a plan view seen from the lower side of the vehicle body in order to schematically explain the members constituting the skeleton of the vehicle in Patent Document 1. FIG.
As shown in FIG. 7, front side members 51 extending in the vehicle front-rear direction are provided on the left and right sides of the front end of the vehicle body, and on the left and right sides of the lower surface of the floor panel 52 behind the front side members 51. A floor side member 53 to be joined is provided. These floor side members 53 are members that extend along the vehicle front-rear direction and are provided to absorb external loads from the front of the vehicle. The front end portions are joined to the rear end portions of the front side members 51, and the front ends It is arranged so as to expand in a “C” shape in a bottom view from the front to the rear end in a straight line extending from the rear part to the rear end part. And the rear-end part of the floor side member 53 is joined to the front-end part of the rear side member 54 extended along the vehicle front-back direction.

  As shown in FIG. 7, a pair of left and right side sills 55 extending along the vehicle front-rear direction is provided on the outer side of the vehicle body of the floor side member 53. A front cross member 56 and a front suspension cross member 57 are connected to each other, and rear cross members 58 and 59 are connected to the rear side frame 54. The floor panel 52 is provided with a floor tunnel 52a. In FIG. 7, W1 is a front wheel and W2 is a rear wheel.

  On the other hand, Patent Document 2 (Japanese Patent Laid-Open No. 2010-82656) has been proposed as another example of a vehicle rear body structure provided with a “C” -shaped floor side member as viewed from below the vehicle.

JP 2010-234939 A JP 2010-82656 A

By the way, in a vehicle such as a small automobile, it is necessary to absorb the external load from the front of the vehicle by the entire floor, and the entire floor structure from the front floor structure to the rear floor structure needs to participate in load distribution.
However, in the conventional structures shown in Patent Documents 1 and 2 described above, the floor side member 53 that absorbs an external load from the front of the vehicle is a straight line from the front end portion to the rear end portion and has a “C” shape in a bottom view. Therefore, the floor tunnel 52a is deformed by an external load from the front of the vehicle. This phenomenon is because, as shown in FIG. 8, the load F from the front of the vehicle acts on the floor side member 53 of the vehicle body skeleton in the direction perpendicular to the force P.
Therefore, in the conventional structure, the load F from the front of the vehicle only acts on the floor tunnel 52a side as the force P in the direction perpendicular to the floor side member 53 of the vehicle body skeleton, so the load F from the front of the vehicle is absorbed. In some cases, it is not possible to obtain a sufficient effect.

  Further, when the deformation due to the load F progresses or the inclination angle α (see FIG. 8) of the “C” -shaped portion with respect to the front-rear direction line increases due to the layout because the vehicle front-rear length is short, the load direction and the skeletal structure The angular difference in the arrangement direction becomes large, a local load is applied, and the floor side member 53 is also deformed to fall, and there is a problem that deformation other than the deformation for compressing the floor tunnel occurs.

  The present invention has been made in view of such a situation, and an object of the present invention is to efficiently apply an external load from the front of the vehicle to the entire floor side member and floor panel without increasing the skeleton and reinforcing the member. An object of the present invention is to provide a lower floor structure of a vehicle body that can be absorbed.

  In order to solve the above-described problems of the prior art, the present invention provides floor side members that are arranged at intervals in the vehicle width direction and are joined to the left and right sides of the floor panel so as to extend in the vehicle front-rear direction. In the lower floor structure of the vehicle body provided with a floor tunnel extending in the vehicle front-rear direction at the center of the floor panel, the planar shape of the floor side member is such that the center line in the width direction of the front end is straight forward of the vehicle. And the width direction center line of the rear end portion is straight toward the rear of the vehicle, and the front half of the intermediate portion in the vehicle longitudinal direction is formed to be curved in a convex shape inward in the vehicle width direction. The latter half portion of the intermediate portion is curved so as to protrude outward in the vehicle width direction.

In the present invention, the rear end portion of the front side member extending along the vehicle front-rear direction is joined to the front end portion of the floor side member, and the rear end portion of the front side member extends in the vehicle width direction. The dash cross member and the dash lower extension are joined to each other, and the floor side member extends from the joined part to the rear of the vehicle, and a suspension frame suspension is provided at the joined part.
Further, in the present invention, the rear end portion of the floor side member includes a side sill that extends in the vehicle front-rear direction on the outer side of the floor side member in the vehicle width direction, and a vehicle width on the inner side of the floor side member in the vehicle width direction. It joins and joins with the rear cross member extended in the direction.

  In the present invention, the floor panel is provided with a floor cross member extending in the vehicle width direction, and is curved in a convex shape inward in the vehicle width direction in an intermediate portion of the floor side member in the vehicle front-rear direction. The floor cross member is joined to a central node between the front half portion and the rear half portion that curves convexly outward in the vehicle width direction.

  In the present invention, the floor panel positioned between the floor tunnel and the front half of the floor side member in the vehicle longitudinal direction, which is curved inwardly in the vehicle width direction, is disposed on the floor panel. A bead or member extending along the width direction is provided.

  Further, in the present invention, the front side member and a rear side member extending along the vehicle longitudinal direction are continuously joined to the front and rear end portions of the floor side member, and the front side member is a straight line extending forward of the vehicle. And a curved portion joined to the floor side member, and the rear side member has a curved portion joined to the floor side member and extending to a rear suspension spring seat, and the front side member is curved. The bent portion of the rear side member is bent in the same manner as the floor side member, and the curved shape is continuous at the front and rear end portions of the floor side member to be joined.

As described above, the floor lower structure of the vehicle body according to the present invention is arranged with an interval in the vehicle width direction, and provided with floor side members joined to the left and right sides of the floor panel extending in the vehicle front-rear direction, A floor tunnel is provided in the center portion of the floor panel so as to extend in the vehicle front-rear direction, and the planar shape of the floor side member is such that the center line in the width direction of the front end portion faces straight forward of the vehicle, and The center line in the width direction of the rear end portion is straight toward the rear of the vehicle, and the front half portion of the middle portion in the vehicle front-rear direction is formed to be convexly curved inward in the vehicle width direction. Since the rear half of the vehicle is convexly curved outward in the vehicle width direction, the curved portion of the floor side member increases when an external load is applied to the floor side member from the front of the vehicle. Deformed, of the vehicle longitudinal direction intermediate portion of the floor side member, the first half is deformed more inwardly, the second half portion will be deformed outwardly.
For this reason, according to the lower floor structure of the present invention, the floor panel and the front half of the floor tunnel are deformed toward the center line of the vehicle body, so that the floor tunnel can be deformed in the closing direction. . Normally, when an external load from the front of the vehicle is applied to the floor tunnel, the floor tunnel is deformed in the opening direction, so that the rigidity of the floor tunnel tends to decrease. It is advantageous for improving or maintaining the rigidity of the tunnel.

Therefore, in the floor lower structure of the present invention, when the floor side member receives an external load from the front of the vehicle, the front portion of the floor tunnel is compressed and deformed, and this deformation further improves the rigidity of the floor tunnel. Thus, an external load from the front of the vehicle can be absorbed efficiently. When the floor side members are arranged in a simple “C” shape as in the prior art, even if an external load is applied from the front of the vehicle, A load absorption effect cannot be expected just by generating a force vector. On the other hand, in the lower floor structure of the present invention, an effect of pressing the floor side member toward the center line side of the vehicle body can be expected due to an increase in curvature due to the S-shaped (or cosine shape) deformation of the floor side member.
In addition, in the lower floor structure of the present invention, since the center line in the width direction of the front and rear end portions of the floor side member faces straight in the vehicle front-rear direction, the efficiency of deforming the floor side member into an S-shaped curve is improved. be able to.

  In the present invention, the rear end portion of the front side member extending along the vehicle front-rear direction is joined to the front end portion of the floor side member, and the rear end portion of the front side member extends in the vehicle width direction. The dash cross member and the dash lower extension are joined to each other, and the floor side member extends from the joined portion to the rear of the vehicle, and the suspension portion is provided with a suspension frame suspension portion. A load transmitted from the side member to the vehicle rear side can be received by the rigid portion of the vehicle body skeleton, that is, the joint portion, and can be transmitted straight to the front end portion of the floor side member. Therefore, according to the lower floor structure of the present invention, the curved deformation of the floor side member can be stably caused, and the effects of the present invention can be further improved.

  Further, in the present invention, the rear end portion of the floor side member includes a side sill that extends in the vehicle front-rear direction on the outer side of the floor side member in the vehicle width direction, and a vehicle width on the inner side of the floor side member in the vehicle width direction. Since it joins and is joined to the rear cross member extending in the direction, the end of the curved shape can be securely fixed by the assembly of the three members, and the deformation of the curved portion can be stabilized. In particular, the curved portion at the rear end of the floor side member can be fixed so as not to open outward, and the entire floor side member can be prevented from falling down.

  In the present invention, the floor panel is provided with a floor cross member extending in the vehicle width direction, and is curved in a convex shape inward in the vehicle width direction in an intermediate portion of the floor side member in the vehicle front-rear direction. The floor cross member is joined to the central node between the front half portion and the rear half portion that curves convexly outward in the vehicle width direction. The deformation of the curve in the portion can be promoted, and the curve deformation of the floor side member can be improved.

  In the present invention, the floor panel positioned between the floor tunnel and the front half of the floor side member in the vehicle longitudinal direction, which is curved inwardly in the vehicle width direction, is disposed on the floor panel. Since the bead or member extending along the width direction is provided, it is possible to efficiently transmit the curved deformation inward in the vehicle width direction of the front half portion of the floor side member to the floor tunnel.

  Further, in the present invention, the front side member and a rear side member extending along the vehicle longitudinal direction are continuously joined to the front and rear end portions of the floor side member, and the front side member is a straight line extending forward of the vehicle. And a curved portion joined to the floor side member, and the rear side member has a curved portion joined to the floor side member and extending to a rear suspension spring seat, and the front side member is curved. And the curved portion of the rear side member are curved in the same manner as the floor side member, and are formed so that the curved shape is continuous at the front and rear end portions of the floor side member to be joined. The front side members and the rear side members before and after the floor side members With bus and can load absorbing curved deformation, the front and rear curved deformation can promote bending deformation of the floor side member. Therefore, according to the lower floor structure of the present invention, the curved deformation of the floor side member can be stably caused, and the effects of the present invention can be further improved.

It is the top view which looked at the floor panel and floor side member to which the floor lower part structure of the vehicle body concerning the embodiment of the present invention was applied from the vehicle lower part. It is the A section enlarged plan view of FIG. It is the B section enlarged plan view of FIG. FIG. 3 is an enlarged plan view showing the vicinity of a suspension frame fastening part in part A of FIG. 2. It is the perspective view which looked at the rear part of the floor panel of this embodiment from the vehicle front. In the floor lower structure of the embodiment of the present invention, it is a diagram showing the degree of curvature of the floor side member due to an external load from the front of the vehicle. It is the top view which looked at the floor panel and floor side member to which the floor lower structure of the prior art was applied from the vehicle downward direction. FIG. 6 is a diagram showing the degree of curvature of the floor side member due to an external load from the front of the vehicle in the floor lower structure of the prior art.

Hereinafter, the present invention will be described in detail based on illustrated embodiments.
1 to 6 show a floor lower structure of a vehicle body according to an embodiment of the present invention.

The lower floor structure of the vehicle body according to the embodiment of the present invention is applied to a vehicle such as a small automobile that needs to absorb an external load from the front of the vehicle on the entire floor, as shown in FIGS. In addition, the skeleton at the lower part of the vehicle body is mainly composed of a floor panel 1, a floor side member 2, a front side member 3, a side sill 4, a rear side member 5, and the like.
A dash panel 11 is provided at the front end portion of the floor panel 1 and is a vertical wall extending along the vehicle width direction for separating the engine room from the vehicle interior. A floor tunnel 12 extending along the vehicle front-rear direction is provided along the vehicle body centerline O (see FIG. 1) at the center in the vehicle width direction on the upper surface of the floor panel 1. Is formed in a cross-sectional hat shape protruding toward the vehicle interior side. In FIG. 1, the arrow X direction indicates the front of the vehicle.

As shown in FIGS. 1 to 3, the floor side member 2, which is a characteristic part of the present embodiment, is a skeleton member that is arranged at intervals in the vehicle width direction and is joined to the left and right sides of the lower surface of the floor panel 1. Yes, extending along the longitudinal direction of the vehicle.
The planar shape of these floor side members 2 is such that the center line C in the width direction of the front end portion 2a is straight forward and the center line C in the width direction of the rear end portion 2b is straight back toward the vehicle. The first half portion 2c1 of the intermediate portion 2c in the direction is formed to be convexly curved inwardly in the vehicle width direction (width direction center line C side), and the second half portion 2c2 of the intermediate portion 2c in the vehicle front-rear direction is Is curved in a convex shape on the outer side (the side opposite to the center line C in the width direction). That is, the overall shape of the floor side member 2 is formed in a gentle continuous curve (S-shape or cosine shape) in which the width W2 of the second half portion 2c2 is set larger than the width W2 of the first half portion 2c1 (FIG. 1). reference).

  Further, as shown in FIGS. 1, 2 and 4, the rear end portions of the front side members 3 are joined to the front end portions 2a of the left and right floor side members 2, respectively. These front side members 3 are arranged at intervals on the left and right sides in the vehicle width direction at the front end portion of the vehicle body, and are provided to extend along the vehicle front-rear direction. The rear end portion of the front side member 3 is joined to a dash cross member 6 and a dash lower extension 7 extending in the vehicle width direction. Suspension portions 31 and 32 of the suspension frame 8 are provided at the joined portion D1. It has been. Accordingly, the joint portion D1 is configured as a rigid portion of the vehicle body skeleton, and the floor side member 2 extends from the joint portion D1 toward the rear of the vehicle.

  Further, of the middle part 2c of the left and right floor side members 2 in the vehicle front-rear direction, the floor panel 1 positioned between the front half part 2c1 and the floor tunnel 12 that curves inwardly in the vehicle width direction includes: As shown in FIGS. 1, 2, and 4, a bead (or member) 13 extending along the vehicle width direction is provided. Therefore, the left and right ends of the bead 13 are connected to the front half 2c1 of the floor side member 2 and the floor tunnel 12, and the deformation of the front half 2c1 of the floor side member 2 is transferred to the floor tunnel 12 via the bead 13. It is configured to be easy to communicate.

  Further, as shown in FIG. 1, the floor panel 1 of the present embodiment is provided with a floor cross member 14 extending in the vehicle width direction. Of the intermediate portion 2c of the floor side member 2 in the vehicle front-rear direction, the center of the front half portion 2c1 that curves convexly inward in the vehicle width direction and the rear half portion 2c2 that curves convexly outward in the vehicle width direction A floor cross member 14 is joined to the node portion, and the curved side member 2 (particularly, the first half portion 2c1) is configured to be deformed with the node as a center.

On the other hand, the rear end 2b of the floor side member 2 of the present embodiment joins the rear end 4a of the side sill 4 and the outer end 9a of the rear cross member 9 as shown in FIGS. And are configured as a three-part joint D2. The side sill 4 is disposed outside the floor side member 2 in the vehicle width direction and extends in the vehicle front-rear direction. The rear cross member 9 is disposed on the inner side in the vehicle width direction of the floor side member 2, is provided to extend in the vehicle width direction, and is joined to a vertical wall surface 1 a formed to protrude from the upper surface of the floor panel 1. Has been. In addition, the parts constituting the joint D2 are also joined to the floor panel 1.
Such a three-part joint D2 firmly fixes the curved end of the rear half portion 2c2 of the intermediate portion 2c of the floor side member 2 in the vehicle front-rear direction, and stabilizes the curved deformation. In particular, the rear end 2b of the floor side member 2 is fixed so as not to open outward in the vehicle width direction. In addition, each component joining in the junction part D2 is not restricted to 3 components, The joining between 2 components may be sufficient.

  Further, as shown in FIGS. 1 and 3, a front side member 3 and a rear side member 5 are continuously joined to the front and rear end portions 2 a and 2 b of the floor side member 2 of the present embodiment. Therefore, the front side member 3 includes a straight portion 3a on the front end side that extends forward of the vehicle, and a rear end portion side that extends rearward from the rear portion of the straight portion 3a and joins to the front end portion 2a of the floor side member 2. It is comprised by the curved part 3b. The rear side member 5 is disposed at intervals on the left and right sides in the vehicle width direction at the rear end of the vehicle body, and extends along the vehicle front-rear direction. Moreover, the rear side member 5 has a curved portion 5a extending from the front end portion joined to the rear end portion 2b of the floor side member 2 to the rear suspension spring seat 33, and the vehicle rear side of the curved portion 5a is a straight portion 5b. It has become.

The curved portion 3b of the front side member 3 and the curved portion 5a of the rear side member 5 are respectively curved with the same phase as the curved shape of the front half portion 2c1 and the rear half portion 2c2 of the floor side member 2, and are joined to the floor side member to be joined. The two front and rear end portions 2a and 2b are formed so that the curved shape is continuous.
When the front side member 3 and the rear side member 5 are curved and deformed, not only the external load from the front of the vehicle is absorbed, but also the curved portions 3b and 5a located at the front and rear of the floor side member 2 are deformed. The bending deformation of the front half part 2c1 and the rear half part 2c2 of the member 2 is promoted.

The operation of the lower floor structure of the vehicle body of the present embodiment having the floor side member 2 configured as described above will be described.
As shown in FIG. 1, when an external load F from the front of the vehicle is applied to the front end of the vehicle body, the load F acts on the center line C in the width direction of the floor side member 2 via the front side member 3. become. In the floor side member 2, as shown in FIG. 6, a force P acts on an external load F from the front of the vehicle, and this force P causes the front half portion 2c1 of the intermediate portion 2c to bend and deform inwardly. The second half portion 2c2 of the intermediate portion 2c is further curved and deformed outward. As a result, the floor panel 1 and the floor tunnel 12 are deformed in the direction of the vehicle body centerline O in the portions near the front ends, and the floor tunnel 12 is deformed in the closing direction. That is, the floor side member 2 that has received the force P compressively deforms the portion near the front end of the floor tunnel 12, and this deformation further improves the rigidity of the floor tunnel 21 and the external load F from the front of the vehicle. Can be efficiently absorbed.

  Thus, in the floor lower structure of the vehicle body according to the embodiment of the present invention, the center line C in the width direction of the front and rear end portions 2a and 2b of the floor side member 2 faces straight in the vehicle front-rear direction, and the middle portion in the vehicle front-rear direction. The front half portion 2c1 of 2c is curved in a convex shape toward the inner side in the vehicle width direction, the rear half portion 2c2 is curved in a convex shape toward the outer side in the vehicle width direction, and the directions of the curved convex shapes are opposite to each other Therefore, when the external load F from the front of the vehicle is applied to the floor side member 2, the front half portion 2c1 is deformed further inward, and the rear half portion 2c2 is deformed further outward, so that the curved portion of the floor side member 2 is deformed. Can be greatly deformed. Therefore, according to the lower floor structure of the present embodiment, when an external load F is applied from the front of the vehicle, the front half of the floor panel 1 and the floor tunnel 12 can be deformed toward the vehicle body centerline O side. Therefore, the floor tunnel 12 can be deformed in the closing direction. In addition, since the center line C in the width direction of the front and rear end portions 2a and 2b of the floor side member 2 faces straight in the vehicle front-rear direction, the floor side member 2 undergoes bending deformation due to the external load F from the front of the vehicle. Can wake up efficiently and stably.

In the floor lower structure of the embodiment of the present invention, the rear end curved portion 3b of the front side member 3 is joined to the front end portion 2a of the floor side member 2, and the rear end curved portion 3b of the front side member 3 is connected to the dash cross. Since the floor side member 2 is joined to the member 6 and the dash lower extension 7, the floor side member 2 extends from the joint D1 to the rear of the vehicle, and the suspension portions 31 and 32 of the suspension frame 12 are provided in the joint D1, the front side member 3 can be received by the joint D1 of the rigid portion of the vehicle body skeleton, and can be transmitted straight to the front end portion 2a of the floor side member 2, so that the curved deformation of the floor side member 2 can be performed. It is possible to wake up more stably.
Furthermore, in the lower floor structure of the embodiment of the present invention, the rear end 2b of the floor side member 2 is formed at the joint D2 that joins and joins the side sill 4 and the rear cross member 9, so that the floor side member The end of the curved shape located in the rear half portion 2c2 of 2 can be securely fixed by a set of three members, and the curved portion of the rear end portion 2b of the floor side member 2 can be held so as not to open outwardly. 2 can be prevented from falling over.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications and changes can be made based on the technical idea of the present invention.

DESCRIPTION OF SYMBOLS 1 Floor panel 2 Floor side member 2a Front end part 2b Rear end part 2c Middle part 2c1 Front half part 2c2 Rear half part 3 Front side member 3a Straight line part 3b Curved part 4 Side sill 5 Rear side member 5a Curved part 6 Dash cross member
7 Dash Lower Extension 8 Suspension Frame 9 Rear Cross Member 12 Floor Tunnel 13 Bead 14 Floor Cross Member 31, 32 Suspension Frame Suspension 33 Rear Suspension Spring Seat C Width Centerline D1, D2 Joint F External Load from Front of Vehicle P Force applied to floor side members
O Body center line

Claims (6)

Floor side members, which are arranged at intervals in the vehicle width direction and are joined to the left and right sides of the floor panel, extend in the vehicle front-rear direction, and a floor tunnel extends in the vehicle front-rear direction at the center of the floor panel. In the floor structure of the floor of the vehicle body
The planar shape of the floor side member is such that the center line in the width direction of the front end portion faces straight forward of the vehicle, and the center line in the width direction of the rear end portion faces straight rearward of the vehicle. The first half portion is formed to be convexly curved inward in the vehicle width direction, and the second half portion of the middle portion in the vehicle front-rear direction is formed to be convexly curved outward in the vehicle width direction. The lower floor structure of the vehicle body.   A rear end portion of the front side member extending along the vehicle front-rear direction is joined to the front end portion of the floor side member, and the rear end portion of the front side member includes a dash cross member and a dash extending in the vehicle width direction. 2. The floor extension according to claim 1, wherein the floor side member is joined to a lower extension, and the floor side member extends from the joint to the rear of the vehicle, and a suspension frame suspension is provided at the joint. Body floor structure as described.   The rear end portion of the floor side member includes a side sill extending in the vehicle front-rear direction on the outer side of the floor side member in the vehicle width direction, and a rear extending in the vehicle width direction on the inner side of the floor side member in the vehicle width direction. The floor lower structure of a vehicle body according to claim 1, wherein the lower structure of the vehicle body is joined to and joined to a cross member.   The floor panel is provided with a floor cross member extending in the vehicle width direction, and of the intermediate portion of the floor side member in the vehicle front-rear direction, a front half portion that curves convexly inward in the vehicle width direction, and the vehicle The floor lower structure of a vehicle body according to any one of claims 1 to 3, wherein the floor cross member is joined to a central node with a rear half portion that curves convexly outward in the width direction.   Of the intermediate portion of the floor side member in the vehicle front-rear direction, the floor panel positioned between the front half portion convexly curved inward in the vehicle width direction and the floor tunnel extends along the vehicle width direction. The floor lower structure of a vehicle body according to any one of claims 1 to 4, wherein an existing bead or member is provided. The front side member and a rear side member extending along the vehicle front-rear direction are continuously joined to the front and rear end portions of the floor side member, and the front side member includes a straight portion extending forward of the vehicle, and the floor side member The rear side member has a curved portion that joins the floor side member and extends to the rear suspension spring seat,
The curved portion of the front side member and the curved portion of the rear side member are curved in the same manner as the floor side member, and are formed so that the curved shape is continuous at the front and rear end portions of the floor side member to be joined. The floor lower structure of a vehicle body according to any one of claims 2 to 5.

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