JP6112671B2 - Auto body structure - Google Patents

Description

  According to the present invention, a CFRP vehicle body floor having a core sandwiched between a floor lower wall and a floor upper wall includes a front inclined portion inclined obliquely forward and upward from a front end of a horizontal portion, and a front side frame is disposed on the front inclined portion. The present invention relates to a vehicle body structure connected to a rear end.

  An energy absorbing member with a honeycomb cross section made of an aluminum alloy extruded material is placed between the rear end of the front side frame and the dashboard lower panel, and the energy absorbing member collapses when a collision load of frontal collision is input to the front side frame. A device that absorbs collision energy is known from Patent Document 1 below.

  Also, the front side frame that extends forward and upward from the dashboard lower panel is made of an aluminum alloy extruded material, and when the impact load of the frontal collision is input, the front side frame is bent upward and the cross section is crushed vertically and the upper wall Patent Document 2 below discloses a technique that prevents the front side frame from being broken and increases the amount of energy absorption by suppressing the elongation of the film.

  In addition, it is composed of an aluminum alloy extruded material in which the side frame is overlapped in multiple stages in the vertical direction, and the strength is increased by increasing the number of overlapping stages from the front-rear direction end to the front-rear direction center, This is known from US Pat.

JP 2009-83756 A Japanese Patent No. 3333719 JP-A-8-104253

  However, what is described in Patent Document 1 described above is that an energy absorbing member having a honeycomb cross section made of an aluminum alloy extruded material cannot avoid being crushed after being crushed by a collision load, and the shock absorbing stroke is reduced. Not only is it difficult to ensure a sufficient amount of collision energy absorption, but it is necessary to make the dashboard lower panel highly rigid in order to generate a reaction force that crushes the energy absorbing member, which increases the weight. there were.

  In addition, in the above-described Patent Document 2, when the front side frame is bent and deformed upward by an input to the collision load, the upper member connected to the front side frame via the damper housing is also bent and deformed upward. There was a problem in that the collapsing energy absorption effect was reduced due to the obstruction of the axial collapse of the upper member.

  In addition, in the above-mentioned Patent Document 3, the front part of the side frame is crushed in the axial direction at the time of a frontal collision, and the rear part of the side frame is crushed in the axial direction at the time of a rearward collision to absorb the collision energy. Since the required shock absorption stroke cannot be ensured only by crushing in the axial direction, there is a problem that it is difficult to sufficiently absorb the collision energy.

  The present invention has been made in view of the above circumstances, and it is an object of the present invention to sufficiently secure a shock absorption stroke and enhance the effect of absorbing collision energy when a collision load of a frontal collision is input to the front side frame. .

In order to achieve the above object, according to the first aspect of the present invention, the CFRP vehicle body floor with the core sandwiched between the floor lower wall and the floor upper wall is inclined obliquely forward and upward from the front end of the horizontal portion. A vehicle body structure having a front inclined portion that connects a rear end of a front side frame to the front inclined portion, wherein the front side frame is bent in a vehicle width direction in a horizontal plane due to a collision load of a frontal collision. A front wall is erected from the front end of the front inclined portion, and a mounting base that supports the front side frame is fixed so as to straddle from the front surface of the front wall to the front surface of the front inclined portion. A vehicle body structure is proposed.

According to the invention described in claim 2, the CFRP vehicle body floor having the core sandwiched between the floor lower wall and the floor upper wall includes a front inclined portion that is inclined obliquely forward and upward from the front end of the horizontal portion, A vehicle body structure in which a rear end of a front side frame is connected to the front inclined portion, wherein the front side frame includes a fragile portion that bends in a vehicle width direction in a horizontal plane due to a collision load of a frontal collision , and the front side frame Comprises a front frame and a rear frame, the front frame is crushed in the axial direction in the early stage of the collision, the rear frame is provided with the fragile part and is bent after the middle of the collision, and the rear end of the front frame and the rear part A vehicle body structure is proposed in which the front end of the frame is coupled through a coupling member having an H-shaped cross section extending in the vertical direction .

According to the invention described in claim 3, the CFRP vehicle body floor having the core sandwiched between the floor lower wall and the floor upper wall includes the front inclined portion that is inclined obliquely forward and upward from the front end of the horizontal portion, A vehicle body structure in which a rear end of a front side frame is connected to the front inclined portion, wherein the front side frame includes a fragile portion that bends in a vehicle width direction in a horizontal plane due to a collision load of a frontal collision , and the front side frame Consists of a front frame and a rear frame, the front frame is crushed in the axial direction at the beginning of the collision, the rear frame is bent after the middle of the collision with the weakened portion, and is connected to the front end of the front side frame A bumper beam extension is provided, and the front end of the rear frame inclines forward and upward in a side view and the front frame in the plan view. Ron DOO sideframe front side inclined outward in the vehicle width direction, the cross-sectional center of the front end of the front side frame body structure of a motor vehicle, characterized in that to match the cross-sectional center of the bumper beam extension is proposed.

According to the invention described in claim 4, the CFRP vehicle body floor with the core sandwiched between the floor lower wall and the floor upper wall includes a front inclined portion that is inclined obliquely forward and upward from the front end of the horizontal portion, A vehicle body structure in which a rear end of a front side frame is connected to the front inclined portion, wherein the front side frame includes a fragile portion that bends in a vehicle width direction in a horizontal plane due to a collision load of a frontal collision , and the front side frame Is a front frame made of an aluminum alloy extruded material having a rectangular cross section, and an inner vertical wall and an outer vertical wall that extend rearward from the rear end of the front frame in the vehicle width direction and connect to the front inclined portion and a rear frame made more, of the inner vertical wall and said outer vertical wall, car auto, characterized in that towards the plate thickness is small constitutes the fragile portion Structure is proposed.

According to the invention described in claim 5 , in addition to the configuration of claim 4 , the inner vertical wall is connected to a floor tunnel side wall portion of the vehicle body floor, and the outer vertical wall is a wheel arch of the vehicle body floor. A vehicle body structure is proposed which is characterized in that it is connected to a part.

  The recess 52f and the inner vertical wall 65 of the embodiment correspond to the weak part of the present invention, the mounting seat 57 of the embodiment corresponds to the hard member of the present invention, and the rear plate 59 of the embodiment corresponds to the present invention. Corresponding to the body mounting part.

According to the first , second, third , and fourth aspects, the CFRP vehicle body floor having the core sandwiched between the lower wall of the floor portion and the upper wall of the floor portion has a front inclined portion that is inclined obliquely forward and upward from the front end of the horizontal portion. Since the rear end of the front side frame is connected to the front side slope, the collision load of the frontal collision input to the front side frame is transmitted and absorbed by the high strength front side slope of the vehicle floor, and the front end of the vehicle floor It is no longer necessary to make the dash panel lower stronger, making it possible to reduce the weight. In addition, the front side frame has a fragile part that bends in the vehicle width direction in the horizontal plane due to the collision load of the frontal collision, so if a frontal collision collision load exceeding a predetermined value is input, the front side frame bends in the horizontal plane starting from the fragile part. The impact absorption stroke can be increased to effectively absorb the collision energy, and the CFRP body floor is not destroyed.

In particular, according to the configuration of claim 1, the front wall is erected from the front end of the front inclined portion, and the mounting base that supports the front side frame is fixed so as to straddle from the front surface of the front wall to the front surface of the front inclined portion. Therefore, it is possible to efficiently absorb the collision load of the frontal collision by transmitting it from the front side frame to the front part of the vehicle body floor via the mounting base and dispersing it. As a result, the collision load that the dash panel lower should bear can be reduced. Therefore, the dash panel lower can be made of a CFRP laminated plate to reduce the weight, and the amount of CFRP material used can be reduced to reduce the cost.

In particular, according to the configuration of claim 2, the front side frame is composed of a front frame and a rear frame, the front frame is crushed in the axial direction in the early stage of the collision, and the rear frame has a fragile part and bends after the middle stage of the collision. A coupling member having an H-shaped cross section that can significantly increase the impact absorption stroke of the front side frame and enhance the impact energy absorption effect, and that extends in the vertical direction at the rear end of the front frame and the front end of the rear frame. Thus, the front frame and the rear frame having different strength and rigidity can be firmly connected with a simple structure.

In particular, according to the configuration of claim 3, the front side frame is composed of a front frame and a rear frame, the front frame is crushed in the axial direction in the initial stage of the collision, and the rear frame is provided with a weak part and bends after the middle stage of the collision. The shock absorption stroke of the front side frame can be greatly increased to increase the impact energy absorption effect, and the front frame frame has a bumper beam extension connected to the front end of the front side frame. The front side frame inclines upward and the front side of the front side frame inclines outward in the vehicle width direction, and the center of the front end of the front side frame coincides with the center of the bumper beam extension. Effective transmission to the front side frame In Rukoto, not only can facilitate the crushing of the bumper beam extension, it is possible to secure a wide engine room to expand the spacing between a front portion of the left and right front side frames.

In particular, according to the configuration of the fourth aspect, the front side frame has a front frame made of an aluminum alloy extruded material having a rectangular cross section, and extends rearward while expanding in the vehicle width direction from the rear end of the front frame. A rear frame consisting of an inner vertical wall and an outer vertical wall connected to the section, and the smaller one of the inner vertical wall and the outer vertical wall constitutes the fragile part. While supporting the load applied to the front side frame, if a collision load of front collision exceeding a predetermined value is input, the front side frame bends in the horizontal plane on the weak inner vertical wall, increasing the shock absorption stroke and effectively making the collision energy In addition to being able to absorb, the CFRP body floor is not destroyed.

According to the fifth aspect of the present invention, the inner vertical wall is connected to the floor tunnel side wall portion of the vehicle body floor, and the outer vertical wall is connected to the wheel arch portion of the vehicle body floor, so that the collision load transmitted from the front side frame is reduced. Dispersed in the floor tunnel side wall and the wheel arch, it is possible to suppress the destruction of the CFRP vehicle body floor due to the concentration of load.

The top view of the front part of the vehicle body frame of a motor vehicle. (First embodiment) FIG. 2 is a two-direction arrow view of FIG. 1. (First embodiment) FIG. 3 is a three-direction arrow view of FIG. 1. (First embodiment) FIG. 4 is a four-direction arrow view of FIG. 1. (First embodiment) FIG. 5 is a sectional view taken along line 5-5 in FIG. (First embodiment) 6A-6A line of FIG. 2, 6B-6B line and 6C-6C line sectional view. (First embodiment) Action | operation explanatory drawing of a front side frame when a collision load is input. (First embodiment) The perspective view of the front part of the vehicle body frame of a motor vehicle. (Second Embodiment) FIG. 9 is a view in the direction of arrow 9 in FIG. 8. (Second Embodiment)

First embodiment

  Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. In the present specification, the front-rear direction, the left-right direction (vehicle width direction), and the up-down direction are defined with reference to an occupant seated in the driver's seat.

  As shown in FIG. 1 and FIG. 2, the front part of the body frame of the automobile mainly made of CFRP (carbon fiber reinforced resin) extends in the front-rear direction along the body floor 11 and the left and right sides of the body floor 11. A pair of left and right side sills 12 and 12 are provided, and a flat dash panel lower 17 is joined to the front end of the vehicle body floor 11 and the front surfaces of the left and right front pillar lowers 13 and 13. A pair of left and right aluminum alloy mounting bases 20, 20 are fixed to the front end of the vehicle body floor 11, and the rear ends of the pair of left and right aluminum alloy front side frames 21, 21 are fixed to the mounting bases 20, 20.

  As shown in FIGS. 1 to 4, a front side frame 21 made of an aluminum alloy extruded material has a front frame 51 positioned on the front side and a rear frame 52 positioned on the rear side, and a coupling member having an H-shaped horizontal cross section. 53 is connected in series. The front frame 51 includes an upper wall 51a, a lower wall 51b, an inner wall 51c in the vehicle width direction, an outer wall 51d in the vehicle width direction, and two partition walls 51e and 51f. It has a constant cross section (see FIG. 6 (A)), and its rear end fits into a “U” -shaped cross section formed by the front part of the pair of side walls 53a and 53b of the coupling member 53 and the partition wall 53c. Fixed by welding. The rear frame 52 includes an upper wall 52a, a lower wall 52b, a vehicle width direction inner wall 52c, a vehicle width direction outer wall 52d, and a single partition wall 52e, and has a “day” -shaped constant cross section in which two hollow portions are arranged vertically. (See FIG. 6 (B)), the front end of which is fitted to the “U” -shaped cross section formed by the rear portions of the pair of side walls 53a and 53b of the coupling member 53 and the partition wall 53c and fixed by welding. Is done.

  The front side frame 21 is formed in a straight line when viewed in the vertical direction, and the front end is slightly inclined outward in the vehicle width direction with respect to the rear end (see FIG. 1). In other words, the distance in the vehicle width direction between the front ends of the pair of left and right front side frames 21 and 21 is slightly wider than the distance in the vehicle width direction between the rear ends. The relatively short front frame 51 is horizontally arranged when viewed from the side, and the relatively long rear frame 52 is inclined from the front upper side to the rear lower side when viewed from the side (see FIG. 2). On the inner wall 52c in the vehicle width direction near the front end of the rear frame 52, a recess 52f having an arcuate cross section extending in the vertical direction is formed. The recess 52f is configured by cutting the inner wall 52c in the vehicle width direction from the upper wall 52a to the lower wall 52b and then welding a lid member 52g to the opening (see FIGS. 3 and 6B).

A lower end of a damper housing 54 die-cast with an aluminum alloy is connected to the upper wall 52a of the rear frame 52. A frame-shaped front subframe 55 that supports an engine, a transmission, a suspension device, and the like (not shown) is supported so as to be suspended from a mounting bracket 56 provided on the lower wall 52b of the rear frame 52 (see FIGS. 1 and 2). ). The recess 52f is disposed at a portion where the damper housing 54 and the front side frame 21 are connected, and faces the mounting seat 57 of the engine fixed to the inner surface of the damper housing 54 in the vehicle width direction. The mounting bracket 56 of the front sub-frame 55 is located between the front end of the rear frame 52 and the recess 52f.
A plate-shaped front plate 58 is fixed to the front end of the front frame 51, and a plate-shaped rear plate 59 is fixed to the rear end of the rear frame 52. A vehicle width direction outer wall 52d of the rear frame 52 and the front surface of the rear plate 59 are connected by a reinforcing gusset 60. A bumper beam extension 61 extending in the front-rear direction is connected to the front end of the front plate 58, and a bumper beam 62 extending in the vehicle width direction is connected to the front ends of the pair of left and right bumper beam extensions 61, 61. The cross-sectional center of the front end of the front side frame 21 is arranged so as to coincide with the cross-sectional center of the bumper beam extension 61 (see FIG. 1).

  The upper member 63 extending forward from the upper end of the front pillar lower 13 includes an upper wall 63a, a lower wall 63b, an inner wall 63c in the vehicle width direction, an outer wall 63d in the vehicle width direction, and a single partition wall 63e, and two hollow portions are arranged vertically. The cross-sectional shape changes so that the front end side becomes thin by cutting out a part of the lower wall 63b and welding the lid member 64 (see FIG. (See FIGS. 3, 4 and 6C). The upper end of the damper housing 54 is connected to the inner wall 63c of the upper member 63 in the vehicle width direction.

  As shown in FIG. 5, the vehicle body floor 11 includes a horizontal portion 11d, a front inclined portion 11e inclined obliquely forward and upward from the front end of the horizontal portion 11d, and a front wall 11f rising from the front end of the front inclined portion 11e. They are composed of a floor lower wall 25c of the under floor panel 25 and a floor upper wall 26a of the upper floor panel 26. A core 33 made of a corrugated plate having an axis extending in the vehicle width direction is sandwiched inside the hollow horizontal portion 11d, and a core 38 made of a corrugated plate having an axis extending in the front-rear direction is held inside the hollow front inclined portion 11e. The solid front wall 11f is joined by bonding the floor lower wall 25c and the floor upper wall 26a directly over each other.

  The dash panel lower 17 joined to the front wall 11f of the vehicle body floor 11 and the left and right front pillar lowers 13 and 13 is composed of a single CFRP laminated plate, and the lower end thereof is overlapped with the front surface of the front wall 11f. Are joined by bonding. The aluminum alloy mounting base 20 fixed to the front surface of the front wall 11f of the vehicle body floor 11 to support the rear plate 59 provided on the front side frame 21 has a substantially trapezoidal cross section that is constant in the vehicle width direction. The four bolts 39 passing through the rear plate 59 pass through the mounting base 20, and then pass through the front wall 11f of the vehicle body floor 11 and the front end of the front inclined portion 11e, and are embedded in the vehicle body floor 11. 40... Further, two bolts 41, 41 penetrating the lower end portion of the mounting base 20 are fastened to nuts 42, 42 embedded in the interior of the vehicle body floor 11. At this time, the extension portion 20c extending rearward and downward from the lower portion of the rear surface of the mounting base 20 is fixed so as to straddle the front surface of the front inclined portion 11e of the vehicle body floor 11.

  Next, the operation of the embodiment of the present invention having the above configuration will be described.

  When a collision load due to a frontal collision of the vehicle is input from the bumper beam 62 to the front side frames 21 and 21 via the pair of left and right bumper beam extensions 61 and 61, the collision load is applied from the front side frames 21 and 21 to the mounting bases 20 and 20. Is transmitted to the front wall 11f of the vehicle body floor 11 and is dispersed and absorbed by the other parts of the vehicle body floor 11 and the side sills 12 and 12 from there. At this time, the extension 20c of the mounting base 20 is fixed so as to straddle from the front surface of the front wall 11f of the vehicle body floor 11 to the front surface of the front inclined portion 11e. The collision energy of the frontal collision can be dispersed in the portion 11e and absorbed more efficiently.

  At that time, the bumper beam extensions 61 and 61 are crushed in the axial direction and absorb a part of the collision load, but are not completely absorbed by the collapse of the bumper beam extensions 61 and 61 and are transmitted to the front side frames 21 and 21. The remaining part of the collision load is absorbed by the crushing and bending of the front side frame 21. That is, the front side frame 21 is composed of a front frame 51 on the front side and a rear frame 52 on the rear side, and the front frame 51 to which a collision load is first transmitted does not have a concave portion that is a fragile portion. It is crushed in the axial direction from the beginning of the collision without bending to absorb the collision energy. On the other hand, the rear frame 52 to which a collision load is input from the front frame 51 is provided with a recess 52f on the inner wall 52c in the vehicle width direction. Therefore, as shown in FIG. The concave portion 52f bends in a “<” shape, and the impact absorption stroke of the front side frame 21 is greatly increased, so that the impact energy absorption effect is enhanced.

  FIG. 7A is an explanatory diagram of the operation of the comparative example in which the front side frame 21 does not have the recess 52f, and when the rear frame 52 is bent in a “<” shape due to the collision load, it does not have the recess 52f. There is a possibility that the amount of extension of the outer wall 52d in the vehicle width direction on the outer side in the bending direction will increase and the portion will break and the impact energy absorption effect will be drastically reduced. On the other hand, FIG. 7B is an operation explanatory view of the embodiment in which the rear frame 52 has the concave portion 52f. When the rear frame 52 is bent into a “<” shape by the collision load, the portion of the concave portion 52f is shown. Since the thickness of the rear frame 52 in the vehicle width direction is reduced, the amount of extension of the vehicle width direction outer wall 52d on the outer side in the bending direction is reduced. As a result, the rear frame 52 is bent at the recess 52f without breaking the outer wall 52d in the vehicle width direction, and can exhibit a sufficient impact energy absorbing effect.

  As described above, the front side frame 21 includes the front frame 51 and the rear frame 52. The front frame 51 is crushed in the axial direction at the beginning of the collision, and the rear frame 52 is provided with the recess 52f and bends after the middle of the collision. The impact absorption effect of the collision energy can be enhanced by greatly increasing the shock absorption stroke of the front side frame 21.

  Also, when a collision load is input to the front side frame 21, if the portion that fixes the rear plate 59 at the rear end of the front side frame 21 to the mounting base 20 falls in the vehicle width direction, the axial direction of the front frame 51 Although crushing and bending of the rear frame 52 may be hindered, the outer wall 52d in the vehicle width direction of the rear frame 52 and the rear plate 59 are connected and reinforced by the gusset 60, so when a collision load of a frontal collision is input. In addition, the rear end of the front side frame 21 is prevented from falling in the vehicle width direction with respect to the mounting base 20, and the front frame 51 is reliably crushed in the axial direction, and the rear frame 52 is reliably bent to collide energy. Can improve the absorption effect.

  Further, a front wall 11f is erected from the front end of a front inclined portion 11e extending frontward and upward from the front portion of the CFRP vehicle body floor 11, and a lower end of a dash panel lower 17 made of a plate-like CFRP laminated plate is connected to the front wall 11f. Since the mounting base 20 that supports the front side frame 21 is fixed so as to straddle from the front surface of the front wall 11f to the front surface of the front inclined portion 11e, the impact load of the frontal collision is removed from the front side frame 21. By being transmitted to the front part of the vehicle body floor 11 and dispersed, it can be absorbed efficiently. As a result, the collision load that the dash panel lower 17 should bear can be reduced. Therefore, the dash panel lower 17 can be made of a CFRP laminated plate to reduce the weight and reduce the amount of use of the CFRP material to reduce the cost. it can.

  Further, since the front frame 51 and the rear frame 52 of the front side frame 21 are made of an aluminum alloy extruded material, the front side frame 21 can be reduced in weight. In addition, since the front side frame 21 includes hollow portions formed in a plurality of stages in the vertical direction, it is possible to ensure necessary strength and rigidity while reducing the weight of the front side frame 21. Further, the number of steps of the hollow portion of the rear frame 52 (two steps) is smaller than the number of steps of the hollow portion of the front frame 51 (three steps), and the recess 52f is formed at a position near the front end of the rear frame 52. By positioning the recess 52f in the vicinity of the coupling member 53 where the strength and rigidity of the front side frame 21 change suddenly, not only can the stress be concentrated in the recess 52f, but the rear frame 52 can be reliably bent, and the rear frame 52 By reducing the height in the vertical direction, the rear portion of the front side frame 21 can be sufficiently overlapped with the front end of the vehicle body floor 11 to which the front side frame 21 is fixed, thereby increasing the load transmission efficiency.

  The recess 52f of the rear frame 52 is adjacent to the engine or transmission mounting seat 57, which is a hard member provided in the damper housing 54. Therefore, the damper housing 54 is reliably broken by the bending of the front side frame 21 to absorb the collision energy. can do.

  Furthermore, since the rear end of the front frame 51 and the front end of the rear frame 52 are coupled via the coupling member 53 having an H-shaped cross section extending in the vertical direction, the front frame 51 and the rear frame 52 having different strengths and rigidity are provided. It can be firmly bonded with a simple structure. In addition, the recess 52f of the rear frame 52 is formed by cutting the inner wall 52c in the vehicle width direction of the rear frame 52 from the upper wall 52a to the lower wall 52b in a circular arc shape and opening the opening formed by the cutting with the lid member 52g. Since it is configured to be closed, not only can the recess 52f be easily formed in the rear frame 52 of a constant cross section, but the impact energy absorption effect can be enhanced by compressing and deforming the lid member 52g by the collision load.

  When viewed in the vertical direction, the front side frame 21 is inclined frontward in the vehicle width direction, and the center of the front end of the front side frame 21 coincides with the center of the cross section of the bumper beam extension 61. Effective transmission from the beam extension 61 to the front side frame 21 not only facilitates the crushing of the bumper beam extension 61, but also increases the distance between the front portions of the left and right front side frames 21 and 21. A large engine room can be secured.

  In addition, since the upper member 63 made of an aluminum alloy extruded material having a reduced cross section at the front end portion is connected to the upper end of the damper housing 54, the upper member 63 is also crushed in the axial direction when a collision load of a frontal collision is input. It can contribute to energy absorption.

  Since the front side frame 21 includes a mounting bracket 56 for supporting the front subframe 55 in front of the recess 52f, a collision load transmitted through the front subframe 55 is applied to the recess 52f so as to act on the front side frame 21. Can be bent more reliably.

  Further, the core 33 of the horizontal part 11d of the vehicle body floor 11 is made of a corrugated sheet having an axis extending in the vehicle width direction, and the core 38 of the front inclined part 11e of the vehicle body floor 11 is made of a corrugated sheet having an axis extending in the front-rear direction. By supporting the collision load of the side collision with the core 33 of the horizontal portion 11d and supporting the collision load of the front collision with the core 38 of the front inclined portion 11e, the vehicle body floor 11 that is strong against both the side collision and the front collision can be obtained. Can be obtained.

Second embodiment

  Next, a second embodiment of the present invention will be described with reference to FIGS.

  The front side frame 21 of the second embodiment includes a front frame 51 made of an aluminum alloy extruded material having a rectangular cross section, an inner vertical wall 65 and an outer vertical wall 66 made of an aluminum alloy plate. A rear frame 52, and a rear end of the front frame 51 and a front end of the rear frame 52 are coupled by a coupling member 53. The front ends of the inner vertical wall 65 and the outer vertical wall 66 are connected to each other at the coupling member 53, but the rear ends are expanded on both sides in the vehicle width direction and straddle the front wall 11f and the front inclined portion 11e of the vehicle body floor 11. The mounting base 20 is fixed. Therefore, the inner vertical wall 65, the outer vertical wall 66, and the mounting base 20 constitute a truss structure in plan view.

  Since the inner vertical wall 65 and the outer vertical wall 66 extend in the vertical direction, the bending rigidity in the vertical direction is high, and the inner vertical wall 65 and the outer vertical wall 66 form a truss structure in cooperation with the mounting base 20. The bending rigidity in the width direction is also increased. And the plate | board thickness of the inner side vertical wall 65 is set smaller than the plate | board thickness of the outer side vertical wall 66, and the inner side vertical wall 65 respond | corresponds to the weak part of this invention.

  A floor tunnel 11a extending in the front-rear direction is formed at the vehicle width direction center portion of the vehicle body floor 11, and the rear end of the inner vertical wall 65 sandwiches the mounting base 20 between the front end of the floor tunnel side wall portion 11g of the floor tunnel 11a. opposite. Further, a wheel arch portion 11h that is recessed in a concave shape is formed in the front inclined portion 11e of the vehicle body floor 11, and the rear end of the outer vertical wall 66 sandwiches the mounting base 20 at the inner end in the vehicle width direction of the wheel arch portion 11h. Connecting.

  Accordingly, while the load applied to the front side frame 21 is usually supported by the rear frame 52 of the truss structure, the inner vertical wall 65 in which the rear frame 52 of the front side frame 21 is fragile when a collision load of a frontal collision exceeding a predetermined value is input. In the horizontal plane, the vehicle can be bent inward in the vehicle width direction to increase the shock absorption stroke of the front side frame 21 to effectively absorb the collision energy, and the vehicle body floor 11 made of CFRP is not destroyed.

  If the plate thickness of the outer vertical wall 66 is made smaller than the plate thickness of the inner vertical wall 65, the rear frame 52 is fragile on the outer vertical wall 66 where the rear frame 52 is fragile due to the input of the collision load of the frontal collision. The collision energy can be effectively absorbed by bending and increasing the shock absorption stroke.

  Further, since the inner vertical wall 65 is connected to the floor tunnel side wall portion 11g of the vehicle body floor 11 and the outer vertical wall 66 is connected to the wheel arch portion 11h of the vehicle body floor 11, the collision load transmitted from the front side frame 21 is applied to the floor tunnel. Dispersed in the side wall portion 11g and the wheel arch portion 11h, it is possible to suppress the destruction of the CFRP vehicle body floor 11 due to load concentration.

  The embodiments of the present invention have been described above, but various design changes can be made without departing from the scope of the present invention.

  For example, in the embodiment, the front side frame 21 is divided into the front frame 51 and the rear frame 52. However, it may be constituted by one member, or may be divided into three or more.

  In the embodiment, the recess 52f of the front side frame 21 is provided on the inner wall 52c in the vehicle width direction of the rear frame 52, but it may be provided on the outer wall 52d in the vehicle width direction.

11 vehicle floor 11d horizontal portion 11e front inclined portion 11f front wall 11g floor tunnel side wall portion 11h wheel arch portion 20 mounting base 21 the front side frame 25c floor subordinates wall 26a floor portion on the wall 33 Core 38 Core 51 front frame 52 rear frame 52f Concave part (fragile part )
53 coupling member 61 the bumper beam Extended sucrose plane 65 inside the vertical wall (weak portion)
66 Outside vertical wall

Claims (5)

The CFRP vehicle body floor (11) with the core (33, 38) sandwiched between the floor lower wall (25c) and the floor upper wall (26a) is inclined forward and inclined obliquely forward and upward from the front end of the horizontal portion (11d). A vehicle body structure including a portion (11e), wherein a rear end of a front side frame (21) is connected to the front inclined portion (11e),
The front side frame (21) includes a weak portion (52f, 65) that bends in the vehicle width direction in a horizontal plane due to a collision load of a frontal collision, and a front wall (11f) is erected from the front end of the front inclined portion (11e). And a mounting base (20) supporting the front side frame (21) is fixed so as to straddle from the front surface of the front wall (11f) to the front surface of the front inclined portion (11e). Car body structure. The CFRP vehicle body floor (11) with the core (33, 38) sandwiched between the floor lower wall (25c) and the floor upper wall (26a) is inclined forward and inclined obliquely forward and upward from the front end of the horizontal portion (11d). A vehicle body structure including a portion (11e), wherein a rear end of a front side frame (21) is connected to the front inclined portion (11e),
The front side frame (21) includes a fragile portion (52f, 65) that bends in the vehicle width direction in a horizontal plane due to a collision load of a frontal collision , and the front side frame (21) includes a front frame (51) and a rear frame ( 52), the front frame (51) is crushed in the axial direction in the initial stage of the collision, and the rear frame (52) is provided with the fragile parts (52f, 65) and bends after the middle stage of the collision. (51) A vehicle body structure characterized in that the rear end of the rear frame (52) and the front end of the rear frame (52) are coupled via a coupling member (53) having an H-shaped cross section extending in the vertical direction . The CFRP vehicle body floor (11) with the core (33, 38) sandwiched between the floor lower wall (25c) and the floor upper wall (26a) is inclined forward and inclined obliquely forward and upward from the front end of the horizontal portion (11d). A vehicle body structure including a portion (11e), wherein a rear end of a front side frame (21) is connected to the front inclined portion (11e),
The front side frame (21) includes a fragile portion (52f, 65) that bends in the vehicle width direction in a horizontal plane due to a collision load of a frontal collision , and the front side frame (21) includes a front frame (51) and a rear frame ( 52), the front frame (51) is crushed in the axial direction in the initial stage of the collision, and the rear frame (52) is provided with the fragile parts (52f, 65) and bends after the middle stage of the collision. A bumper beam extension (61) connected to the front end of (21), the front end of the rear frame (52) is inclined forward and upward in a side view, and the front side frame (21) is Inclined outward in the vehicle width direction, and the center of the cross section of the front end of the front side frame (21) is the bumper beam extender. Body structure of a motor vehicle, characterized in that to match the cross-sectional center of the ® emission (61). The CFRP vehicle body floor (11) with the core (33, 38) sandwiched between the floor lower wall (25c) and the floor upper wall (26a) is inclined forward and inclined obliquely forward and upward from the front end of the horizontal portion (11d). A vehicle body structure including a portion (11e), wherein a rear end of a front side frame (21) is connected to the front inclined portion (11e),
The front side frame (21) includes a fragile portion (52f, 65) that is bent in the vehicle width direction in a horizontal plane due to a collision load of a frontal collision , and the front side frame (21) is made of an aluminum alloy extruded material having a rectangular cross section. A front frame (51), an inner vertical wall (65) that extends rearward from the rear end of the front frame (51) in the vehicle width direction and connects to the front inclined portion (11e) and an outer vertical wall A rear frame (52) comprising a wall (66), and the smaller one of the inner vertical wall (65) and the outer vertical wall (66) constitutes the fragile portion (65). Characteristic car body structure . Before Symbol inner vertical wall (65) is connected to the floor tunnel side wall portion of the vehicle body floor (11) (11g), said outer vertical wall (66) is connected to the wheel arch portion (11h) of said vehicle body floor (11) The vehicle body structure according to claim 4 , wherein the vehicle body structure is a vehicle.

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