JP6195166B2 - Auto body structure - Google Patents

Description

  The present invention is a vehicle body floor comprising a floor tunnel portion having an inverted U-shaped cross section disposed in the front-rear direction at the center in the vehicle width direction, and a pair of left and right floor portions continuous on both sides in the vehicle width direction of the floor tunnel portion. The present invention relates to a vehicle body structure constituted by a CFRP under floor panel and a CFRP upper floor panel.

  A recess is formed in the rear wall of the dash panel lower of the vehicle body floor that is configured in a bathtub shape with CFRP, and a floor tunnel portion is formed in the floor panel of the vehicle body floor so that the ridgeline of the recess and the ridgeline of the floor tunnel portion are continuous. Patent Document 1 below discloses a technique for efficiently transmitting and absorbing a collision load of a frontal collision from a dash panel lower to a floor tunnel portion.

  In addition, the FRP floor tunnel part of automobiles is pressure-molded by combining a plurality of prepreg pieces cut into a predetermined shape in a mold, thereby accurately controlling the product thickness while improving the prepreg yield. This is known from Patent Document 2 below.

WO2013 / 128619 JP 2008-290421 A

  By the way, although what was described in the said patent document 1 is disclosing about the transmission path | route of the collision load from a dash panel lower to a floor tunnel part, the structure for improving the intensity | strength of the CFRP panel which comprises a floor tunnel part Is not disclosed at all.

  In addition, what is described in Patent Document 2 is intended to improve the yield of the prepreg of the floor tunnel portion made of CFRP and to manage the thickness of the sheet, and does not disclose any configuration for improving the strength against a collision load. Not done.

  The present invention has been made in view of the above circumstances, and an object thereof is to reduce the weight, improve the strength, and improve the formability of a CFRP vehicle body floor that is integrally provided with a floor tunnel portion.

To achieve the above object, according to the first aspect of the present invention, a floor tunnel portion having an inverted U-shaped cross section disposed in the front-rear direction at the center in the vehicle width direction, and the vehicle width direction of the floor tunnel portion. A vehicle body structure in which a vehicle body floor including a pair of left and right floor portions continuous on both sides is composed of a CFRP underfloor panel and a CFRP upper floor panel, before standing up from the front end of the vehicle body floor A mounting pedestal of a pair of left and right front side frames is fixed to the front surface of the front wall, the vehicle width direction inner end of the mounting pedestal faces the front end of the tunnel side wall, and the vehicle body floor direction A pair of left and right side sills are joined to the outer ends, and a single dash panel lower composed of a stack of CFRP sheets is joined to the front wall of the vehicle body floor. A front pillar lower standing from the front end of the dosill is joined to an outer end in the vehicle width direction of the dash panel lower, and an opening through which a steering shaft passes is formed in the dash panel lower, and the vehicle body floor is wider in the vehicle width direction than the side sill. A pair of left and right protrusions extending outward from the outer end of the tunnel upper wall and the tunnel upper wall in the vehicle width direction. A tunnel portion side wall and a floor portion lower wall extending outward in the vehicle width direction from the lower ends of the pair of left and right tunnel portion side walls, and the upper floor panel extends from the middle portion of the pair of left and right tunnel portion side walls in the vehicle width direction. comprising a pair of left and right floor portions on the walls extending outward, the junction of the tunnel portion on the wall and the tunnel portion side wall phase With overlap to the wall thickness is increased, the vehicle body structure of an automotive vehicle is proposed, wherein a thickness and phase overlap each other in the junction of the tunnel portion side wall and the floor subordinates wall increases .

According to the second aspect of the present invention, in addition to the configuration of the first aspect, the tunnel portion upper wall and the junction portion of the tunnel portion side wall overlap each other across the ridgeline so as to overlap the lower surface side and the vehicle. The thickness increases on the inner surface side in the width direction, and the junction between the side wall of the tunnel portion and the lower wall of the floor portion overlaps each other across the ridgeline, and the thickness increases on the outer surface side and the upper surface side in the vehicle width direction. A vehicle body structure characterized by the above is proposed.

According to the invention described in claim 3, in addition to the configuration of claim 1 or claim 2 , the pair of left and right tunnel side walls expands outward in the vehicle width direction toward the front. A car body structure is proposed.

According to the invention described in claim 4, in addition to the structure of any one of claims 1 to 3, the vehicle body floor includes a first bent portion that extends in the vehicle width direction at the front end of the horizontal portion. A front inclined portion inclined obliquely forward and upward, a front wall standing upward from a second bent portion extending in the vehicle width direction at the front end of the front inclined portion, and extending in the vehicle width direction at the rear end of the horizontal portion the third body structure of a motor vehicle, characterized in that it comprises a side inclined portion after inclined from the bent portion upward after obliquely Ru been proposed.

According to the invention described in or claim 5, in addition to any one of claims 1 to 4, the upper end of the front wall of the vehicle body floor level with the upper end of the side sill body structure of a motor vehicle, characterized in that in the Ru been proposed.

According to the invention described in claim 6 were or, in addition to any one of claims 1 to 5, wherein the under floor panel is composed of CFRP panels stacked UD prepregs to 12 layers An automobile body structure is proposed in which the overlapping amount of the joint is 30 mm.

According to the structure of Claim 1, the floor tunnel part of the reverse U-shaped cross section arrange | positioned in the vehicle width direction center in the front-back direction, and a pair of left and right floor parts continuous on both sides in the vehicle width direction of the floor tunnel part are provided. The vehicle body floor includes a CFRP under floor panel and a CFRP upper floor panel.

  The under-floor panel includes a tunnel section upper wall, a pair of left and right tunnel section sidewalls extending downward from the outer end in the vehicle width direction of the tunnel section upper wall, and a floor section section extending outward in the vehicle width direction from the lower ends of the pair of left and right tunnel section sidewalls. The junction between the tunnel upper wall and the tunnel side wall overlaps each other to increase the thickness, and the tunnel side wall and the floor lower wall junction overlap each other to increase the wall thickness. Since it increases, a floor tunnel part can be comprised only with an underfloor panel, and required intensity | strength can be ensured, aiming at weight reduction. In addition, the upper floor panel includes a pair of left and right floor upper walls that extend outward in the vehicle width direction from the vertical middle portion of the pair of left and right tunnel side walls. Therefore, the upper floor panel is configured with a flat CFRP panel during molding. In addition to facilitating shaping, it is possible to increase the strength by eliminating bent portions where stress is likely to concentrate.

  Also, it has a front wall that stands up from the front end of the vehicle body floor, the mounting base of the pair of left and right front side frames is fixed to the front of the front wall, and the inner end in the vehicle width direction of the mounting base faces the front end of the tunnel side wall The collision load of the frontal collision input to the front side frame can be efficiently transmitted from the mounting base to the floor tunnel portion and absorbed.

  In addition, a pair of left and right side sills are joined to the vehicle width direction outer end of the vehicle body floor, and a single-plate dash panel lower formed by stacking CFRP sheets is joined to the front wall of the vehicle body floor and stands from the front end of the side sill. Since the front pillar lower is joined to the outer edge of the dash panel lower in the vehicle width direction, it is a single plate, so it is lightweight but has relatively low strength. In addition to being transmitted to the front wall, it is possible to suppress the breakage of the dash panel lower by being distributed to the front end of the side sill via the front pillar lower. In addition, since the opening through which the steering shaft passes is formed in the dash panel lower, the steering shaft can be easily turned from the rear to the front of the dash panel lower.

  Also, the vehicle body floor has a protrusion that protrudes outward in the vehicle width direction from the side sill, and the energy absorbing member is disposed at least in the protrusion, so that the collision load of the side collision is input to the protrusion of the vehicle floor before the side sill. By absorbing a part of the collision energy by the crushing of the energy absorbing member disposed in the protruding portion of the vehicle body floor, the side sill can be prevented from falling inward in the vehicle width direction.

According to the structure of claim 2, the junction between the tunnel portion upper wall and the tunnel portion side wall overlaps each other across the ridgeline, and the thickness increases on the lower surface side and the vehicle width direction inner surface side. The joint between the side wall and the floor lower wall overlaps each other across the ridgeline, and the thickness increases on the outer side and the upper side in the vehicle width direction. Necessary strength can be ensured while planning.

  According to the third aspect of the present invention, the pair of left and right tunnel side walls are expanded outward in the vehicle width direction toward the front, so that the collision load of the frontal collision input to the front side frame affects the position of the mounting base. Without being transmitted to the floor tunnel.

According to the fourth aspect of the present invention, the vehicle body floor has a front inclined portion inclined obliquely forward and upward from a first bent portion extending in the vehicle width direction at the front end of the horizontal portion, and a vehicle width direction at the front end of the front inclined portion. A front wall that rises upward from the second bent portion that extends and a rear inclined portion that tilts obliquely rearward and upward from the third bent portion that extends in the vehicle width direction at the rear end of the horizontal portion. shaping becomes hardly deviation wrinkles in the prepreg is easily ing upon integral molding.

According to or the configuration of claim 5, the upper end of the front wall of the vehicle body floor at the same height as the upper end of the side sill, the crash load on the front collision input to the front wall of the vehicle body floor side sill efficiently transferred Ru can be absorbed by.

According to or structure of claim 6, the under floor panel is composed of CFRP panels stacked UD prepregs to 12 layers, the amount of overlap joints since it is 30 mm, to ensure a sufficient strength of the joint be able to.

The perspective view of the vehicle body frame of a motor vehicle. FIG. 2 is a two-direction arrow view of FIG. 1. FIG. 3 is a three-direction arrow view of FIG. 1. 4A direction view and 4B direction arrow view of FIG. FIG. 5 is a sectional view taken along line 5-5 of FIG. FIG. FIG. 7 is a cross-sectional view taken along line 7-7 in FIG.

  Hereinafter, embodiments 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 FIGS. 1 to 3, an automobile body frame mainly made of CFRP (carbon fiber reinforced resin) includes a body floor 11 and a pair of left and right sides extending in the front-rear direction along the left and right sides of the body floor 11. Side sills 12, 12; a pair of left and right front pillars 13 and 13 standing up front from the front ends of the left and right side sills 12, 12, and a pair of left and right rear pillars rising up from the rear ends of the left and right side sills 12, 12. 14, 14 and a pair of left and right center pillars 15 and 15 rising upward from the middle part in the front-rear direction of the left and right side sills 12 and 12, and the left and right center pillars 15 and 15 from the upper ends of the left and right front pillar lowers 13 and 13. A pair of left and right upper members 16, 16 extending to the upper ends of the left and right rear pillars 14, 14 via the upper ends are provided. As for the upper members 16 and 16, the front half constitutes a front pillar upper, and the rear half constitutes a roof side rail.

  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, 13, and a flat plate rear portion is connected to the rear end of the vehicle body floor 11 and the rear surfaces of the left and right rear pillars 14, 14. The partition wall 18 is joined, and the rear pershell 19 extends horizontally from the rear end of the rear partition wall 18. 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 a pair of left and right aluminum alloy front side frames 21, 21 are fixed to the front ends of the mounting bases 20, 20. . A pair of left and right rear side frames 22, 22 extend rearward from the rear end of the vehicle body floor 11, and the rear pillars 14, 14 and the rear side frames 22, 22 are joined by a pair of left and right rear wheel house inners 23, 23. The upper ends of the left and right center pillars 15 and 15 are joined by the roof arch 24.

  As shown in FIG. 7, the vehicle body floor 11 has an inverted U-shaped floor tunnel portion 11a extending in the vehicle width direction center portion in the front-rear direction, and a pair of left and right floor portions when continuous on both sides of the floor tunnel portion 11a in the vehicle width direction. 11b, 11b. The under floor panel 25 includes a tunnel portion upper wall 25a, a pair of left and right tunnel portion side walls 25b and 25b extending downward from the outer end in the vehicle width direction of the tunnel portion upper wall 25a, and a vehicle width from the lower end of the tunnel portion side walls 25b and 25b. Floor portion lower walls 25c, 25c extending outward in the direction, and the floor portion upper walls 26a, 26a of the pair of left and right upper floor panels 26, 26 are formed to be substantially flat along the upper surfaces of the floor portion lower walls 25c, 25c. The

  The under floor panel 25 and the upper floor panels 26 and 26 are obtained by laminating UD prepregs of carbon fibers in 12 layers and curing them in a predetermined shape. The orientation of the carbon continuous fibers of the 12-layer CFRP sheet The direction is two repetitions of + 60 °, −60 °, 0 °, 0 °, −60 °, and + 60 ° when the front-rear direction is 0 °.

  The floor tunnel portion 11a includes a tunnel portion upper wall 25a of the underfloor panel 25 and a pair of left and right tunnel portion side walls 25b and 25b. The junction portion 27 of the tunnel portion upper wall 25a and the tunnel portion side walls 25b and 25b has 12 The CFRP sheets of the layers are overlapped over a length of 30 mm, and the thickness is doubled at the overlap portion. Further, the joint portion 28 of the tunnel side walls 25b and 25b and the floor lower walls 25c and 25c is obtained by overlapping 12 layers of CFRP sheets over a length of 30 mm, and the thickness is doubled at the overlap portion. It has become. Similarly, the junction 29 of the tunnel side walls 25b and 25b and the floor upper walls 26a and 26a of the upper floor panel 26 is obtained by overlapping 12 layers of CFRP sheets, and the thickness is doubled at the overlap portion. It has become.

  At the outer end of the vehicle body floor 11 in the vehicle width direction, a joint flange 25d that is bent upward in the vehicle width direction of the floor lower wall 25c of the under floor panel 25, and the vehicle width of the floor upper wall 26a of the upper floor panel 26. A joining flange 26b whose outer end in the direction is bent upward is overlapped and joined. The vehicle width direction outer end portion of the vehicle body floor 11 is thicker in the vertical direction than the vehicle width direction central portion, and a pair of upper and lower energy absorbing members 30 and 30 are disposed in the thickened portion. The energy absorbing members 30 and 30 are made of a corrugated member made of PA (polyamide) or nylon excellent in shock absorbing performance.

  A support wall 31 is fixed to the inner side in the vehicle width direction of the energy absorbing members 30, 30 by adhesion, and the energy absorbing members 30, 30 are fitted into fitting grooves formed on the outer surface of the support wall 31 in the vehicle width direction. Joined by adhesion. The upper surfaces of the energy absorbing members 30 and 30 are bonded to the lower surface of the upper floor panel 26 by bonding, and the lower surfaces of the energy absorbing members 30 and 30 are bonded to the upper surface of the under floor panel 25 by bonding.

  A load distribution frame 32 made of CFRP (or made of aluminum) extending in the front-rear direction is disposed on the inner side of the support wall 31 in the vehicle width direction and where the thickness of the floor portion 11b changes. The upper surface and the lower surface of the load distribution frame 32 are bonded to the lower surface of the upper floor panel 26 and the upper surface of the under floor panel 25, respectively, and the outer surface in the vehicle width direction is bonded to the inner surface in the vehicle width direction of the support wall 31. Corrugated cores 33 and 33 are disposed inside the floor portion 11b on the inner side in the vehicle width direction of the load distribution frame 32, and the upper and lower surfaces thereof are bonded to the lower surface of the upper floor panel 26 and the upper surface of the under floor panel 25, respectively. Be joined.

  The side sill 12 has a closed cross section formed by joining the outer member 34 and the inner member 35, and a plurality of partition plates 36 are arranged at predetermined intervals in the front-rear direction. The side sill 12 is placed on the upper surface of the upper floor panel 26 and joined by bonding at the outer end in the vehicle width direction of the vehicle body floor 11, that is, at the upper part of the energy absorbing member 30. The protruding portion 11c formed at the end protrudes outward in the vehicle width direction by a distance α from the outer end in the vehicle width direction of the side sill 12, and thus the outer end portion in the vehicle width direction of the energy absorbing member 30 extending into the protruding portion 11c is the side sill. It protrudes outward in the vehicle width direction by a distance α from 12 outer ends in the vehicle width direction. The upper and lower ends of the crank-shaped connecting member 37 made of CFRP plate material are bonded to the outer end in the vehicle width direction of the side sill 12 and the connecting flanges 26b and 25d of the upper floor panel 26 and the under floor panel 25, respectively. Is done.

  With the side sill 12 joined to the vehicle body floor 11, the upper end of the side sill 12 and the upper end of the front wall 11f of the vehicle body floor 11 are aligned at the same height (see FIG. 3).

  As shown in FIG. 5, the vehicle body floor 11 includes a horizontal portion 11d located in the center in the front-rear direction, a front inclined portion 11e inclined obliquely forward and upward from the front end of the horizontal portion 11d, and upward from the front end of the front inclined portion 11e. It includes a standing front wall 11f, a rear inclined portion 11g inclined obliquely rearward and upward from the rear end of the horizontal portion 11d, and a rear horizontal portion 11h extending rearward from the rear end of the rear inclined portion 11g. The first bent portion B1 at the boundary between the horizontal portion 11d and the front inclined portion 11e, the second bent portion B2 between the front inclined portion 11e and the front wall 11f, and the third bent portion between the horizontal portion 11d and the rear inclined portion 11g B3 and the fourth bent portion B4 between the rear inclined portion 11g and the rear horizontal portion 11h extend in parallel to each other along the vehicle width direction. Therefore, when the under floor panel 25 and the upper floor panels 26 and 26 of the vehicle body floor 11 are formed by CFRP, the UD prepreg is less likely to wrinkle and shaping is facilitated.

  As shown in FIGS. 1 to 6, the dash panel lower 17 joined to the front wall 11 f of the vehicle body floor 11 and the left and right front pillar lowers 13, 13 is composed of a single CFRP plate, An opening 17a through which a steering shaft (not shown) passes is formed in the lower part. A pair of left and right mounting bases 20 and 20 are fixed to the front surface of the front wall 11f of the vehicle body floor 11, and the rear side of the inner ends in the vehicle width direction of the left and right mounting bases 20 and 20 is outward in the vehicle width direction. The front ends of the pair of left and right tunnel part side walls 25b, 25b of the floor tunnel part 11a that expands to the opposite side face each other.

  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 to the front side frames 21, 21, the collision load is applied from the front side frames 21, 21 to the front wall 11 f of the vehicle body floor 11 via the mounting bases 20, 20 and the dash panel lower 17. Communicated. At this time, the dash panel lower 17 composed of a single plate for weight reduction does not have the strength to support the collision load, but the inner ends of the mounting bases 20 and 20 in the vehicle width direction are not provided. Since it faces the front ends of the left and right tunnel part side walls 25b, 25b of the floor tunnel part 11a of the vehicle body floor 11, the collision load is efficiently transmitted from the mounting bases 20, 20 to the tunnel part side walls 25b, 25b (FIG. 4 ( B)), it is possible to prevent the dash panel lower 17 from being broken by dispersing and absorbing the entire vehicle body floor 11 from there.

  At that time, since the pair of left and right tunnel side walls 25b and 25b expand in the vehicle width direction toward the front, the collision load of the frontal collision input to the front side frames 21 and 21 is used as the position of the mounting bases 20 and 20. Can be efficiently transmitted to the tunnel side walls 25b and 25b without being affected by the above.

  The floor tunnel portion 11a to which the collision load is transmitted includes a tunnel portion upper wall 25a of the under floor panel 25 and left and right tunnel portion side walls 25b and 25b, and a joint portion between the tunnel portion upper wall 25a and the tunnel portion side walls 25b and 25b. 27 is overlapped with each other and the thickness is increased, and the junction 28 of the tunnel side walls 25b and 25b and the floor lower walls 25c and 25c is overlapped with each other to increase the thickness (see FIG. 7). The floor tunnel portion 11a can be constituted by only the underfloor panel 25 to ensure the necessary strength while reducing the weight.

  At this time, the under floor panel 25 is composed of a CFRP panel in which UD prepregs are laminated in 12 layers, and the overlapping amount of the joint portions 27 and 28 is 30 mm, so that the strength of the joint portions 27 and 28 is sufficiently ensured. Can do.

  Moreover, the upper floor panels 26 and 26 include a pair of left and right floor portion upper walls 26a and 26a that extend outward in the vehicle width direction from the middle portion in the vertical direction of the pair of left and right tunnel portion side walls 25b and 25b. Can be formed by a flat CFRP panel to facilitate shaping during molding, and the strength can be increased by eliminating a bent portion where stress tends to concentrate.

  A pair of left and right side sills 12, 12 are joined to the vehicle width direction outer end of the vehicle body floor 11, and the lower end of the dash panel lower 17 is joined to the front wall 11 f of the vehicle body floor 11 so as to stand up from the front ends of the side sills 12, 12. Since the front pillar lowers 13 and 13 are joined to the outer end in the vehicle width direction of the dash panel lower 17, the collision of the frontal collision input to the dash panel lower 17 that is light because it is a single plate but relatively low in strength. By not only transmitting the load to the front wall 11f of the vehicle body floor 11, but also distributing the load to the front ends of the side sills 12 and 12 via the front pillar lowers 13 and 13, the dash panel lower 17 can be prevented from being broken. Moreover, since the opening 17a through which the steering shaft passes is formed in the dash panel lower 17, the steering shaft can be easily turned from the rear to the front of the dash panel lower 17.

  At that time, since the upper end of the front wall 11f of the vehicle body floor 11 is at the same height as the upper ends of the side sills 12 and 12 (see FIG. 3), the collision load of the frontal collision input to the front wall 11f of the vehicle body floor 11 is 12 and 12 can be efficiently transmitted and absorbed.

  When a collision load due to a side collision of the vehicle is input to the side portion of the vehicle body floor 11, the vehicle body floor 11 includes a protrusion 11 c that protrudes outward in the vehicle width direction from the outer end in the vehicle width direction of the side sill 12. Since at least a part of the energy absorbing members 30 and 30 is disposed in 11c (see FIG. 7), the collision load of the side collision is input to the protruding portion 11c of the vehicle body floor 11 before the side sill 12, and the inside of the protruding portion 11c By absorbing a part of the collision energy by crushing the energy absorbing members 30, 30, the side sill 12 is crushed without falling inward in the vehicle width direction, and the effect of absorbing the collision energy is further enhanced.

  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, the number of prepregs stacked and the overlap length of the tunnel portion upper wall 25a, tunnel portion side walls 25b and 25b, and floor portion lower walls 25c and 25c are not limited to the embodiment, and can be arbitrarily set.

11 Car body floor 11a Floor tunnel portion 11b Floor portion 11c Protruding portion 11d Horizontal portion 11e Front inclined portion 11f Front wall 11g Rear inclined portion 12 Side sill 13 Front pillar lower 17 Dash panel lower 17a Opening 20 Mounting base 21 Front side frame 25 Under floor Panel 25a Tunnel portion upper wall 25b Tunnel portion side wall 25c Floor portion lower wall 26 Upper floor panel 26a Floor portion upper wall 27 Joint portion 28 Joint portion 30 Energy absorbing member B1 First bent portion B2 Second bent portion B3 Third bent portion

Claims (6)

A floor tunnel portion (11a) having an inverted U-shaped cross section disposed in the front-rear direction at the center in the vehicle width direction, and a pair of left and right floor portions (11b) continuous on both sides of the floor tunnel portion (11a) in the vehicle width direction. A vehicle body structure comprising a vehicle body floor (11) comprising a CFRP under floor panel (25) and a CFRP upper floor panel (26),
A front wall (11f) standing up from a front end of the vehicle body floor (11) is provided, and a mounting base (20) of a pair of left and right front side frames (21) is fixed to a front surface of the front wall (11f), and the mounting base A vehicle width direction inner end of (20) faces the front end of the tunnel side wall (25b), a pair of left and right side sills (12) is joined to the vehicle width direction outer end of the vehicle body floor (11), and a CFRP sheet A single-plate dash panel lower (17) constructed by laminating a front pillar (13) is joined to the front wall (11f) of the vehicle body floor (11) and stands up from the front end of the side sill (12). Are joined to the vehicle width direction outer end of the dash panel lower (17), and an opening (17a) through which a steering shaft passes is formed in the dash panel lower (17). 1) includes a protruding portion (11c) protruding outward in the vehicle width direction from the side sill (12), an energy absorbing member (30) is disposed at least in the protruding portion (11c), and the under floor panel (25 ) Includes a tunnel part upper wall (25a), a pair of left and right tunnel part side walls (25b) extending downward from an outer end in the vehicle width direction of the tunnel part upper wall (25a), and the pair of left and right tunnel part side walls (25b). ) And a floor portion lower wall (25c) extending outward in the vehicle width direction from the lower end of the upper wall panel), and the upper floor panel (26) extends outward in the vehicle width direction from an intermediate portion in the vertical direction of the pair of left and right tunnel portion side walls (25b). A pair of left and right floor upper walls (26a) extending, and the junction (27) of the tunnel upper wall (25a) and the tunnel side wall (25b) overlap each other. The thickness of the vehicle body structure increases as the thickness of the tunnel portion side wall (25b) and the joint portion (28) of the floor portion lower wall (25c) overlap each other. . The tunnel portion upper wall (25a) and the junction portion (27) of the tunnel portion side wall (25b) overlap each other across the ridgeline and increase in thickness on the lower surface side and the vehicle width direction inner surface side. The junction part (28) of the tunnel side wall (25b) and the floor lower wall (25c) overlaps each other across the ridgeline, and the thickness increases on the outer surface side and the upper surface side in the vehicle width direction. The vehicle body structure according to claim 1. The vehicle body structure according to claim 1 or 2 , wherein the pair of left and right tunnel side walls (25b) expands outward in the vehicle width direction toward the front. The vehicle body floor (11) includes a front inclined portion (11e) inclined obliquely forward and upward from a first bent portion (B1) extending in the vehicle width direction at a front end of the horizontal portion (11d), and the front inclined portion (11e). The front wall (11f) standing upward from the second bent portion (B2) extending in the vehicle width direction at the front end of the second portion and the third bent portion (B3) extending in the vehicle width direction at the rear end of the horizontal portion (11d) The vehicle body structure according to any one of claims 1 to 3, further comprising a rear inclined portion (11g) inclined obliquely rearward and upward from the front. The upper end of the front wall (11f) of the vehicle body floor (11) is at the same height as the upper end of the side sill (12), according to any one of claims 1-4 . Auto body structure. The said under floor panel (25) is comprised by the CFRP panel which laminated | stacked UD prepreg on 12 layers, and the overlap amount of the said junction part (27,28) is 30 mm, The Claims 1- Claim characterized by the above-mentioned. 6. The vehicle body structure according to any one of 5 above.

Images