JP2014136436A - Automotive vehicle body structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an automotive vehicle body structure with high robustness that is low weight and can exert impact absorbing performance even though position of a bumper beam of the other vehicle causing rear-surface collision is shifted vertically from position of a bumper beam of an own vehicle.SOLUTION: A rear panel 40 made of resin for fiber reinforcement connected to the rearward of a floor 11 made of resin for fiber reinforcement comprises: a lower wall 40a; left and right lateral walls 40b rising up from both lateral edges of the lower wall 40a in a vehicle width direction; and a back wall 40c rising up from the back wall of the lower wall 40a. On upper ends of the left and right lateral walls 40b is provided a lateral wall flange 40d that is folded outside in the vehicle width direction to incline backward and downward. A hat-shaped cross-section member 41 made of resin for fiber reinforcement connected to a back end of a roof-side rail 33 is connected to an upper surface of the lateral wall flange 40d to compose an upper member 38 of a hollow closed cross section. The back end of the upper member 38 is connected to a back wall flange 40e extending backward from the upper end of the back wall 40c and a rear bumper beam 36 is connected to the back wall 40c.

Description

  The present invention relates to a vehicle body structure of an automobile made of fiber reinforced resin, in which a rear bumper beam is connected to the rear of an automobile floor via a rear panel.

  The automobile cabin is integrally molded with fiber reinforced resin, and a metal front frame that absorbs energy by plastic deformation due to the collision load of frontal collision is provided at the front of the cabin, and collision of rear collision occurs at the rear of the cabin. Patent Document 1 listed below discloses a metal rear frame that absorbs energy by plastic deformation under load.

US Pat. No. 7,264,304

  By the way, although what was described in the said patent document 1 can reduce in weight by integrally forming the cabin of a motor vehicle with fiber reinforced resin, a collision load is made with a metal front frame or a metal rear frame. In order to absorb, there is a problem that it is necessary to sufficiently secure the front and rear lengths of the metal frames, and there is a problem that the advantages of reducing the weight of the cabin due to the increase in the weight of the metal frames cannot be fully utilized.

  The present invention has been made in view of the above-mentioned circumstances, and is lightweight, but exhibits shock absorbing performance even when the bumper beam position of another vehicle that collides rearward is shifted vertically from the position of the bumper beam of the own vehicle. An object of the present invention is to provide an automobile body structure having high robustness.

  To achieve the above object, according to the first aspect of the present invention, the rear panel made of fiber reinforced resin connected to the rear of the floor made of fiber reinforced resin has at least a lower wall and a vehicle width of the lower wall. Left and right side walls rising from both side edges in the direction and a rear wall rising from the rear edge of the lower wall, and provided with side wall flanges that are bent outward in the vehicle width direction and inclined rearward and downward at the upper ends of the left and right side walls. A hat-shaped cross-section member made of fiber reinforced resin connected to the rear end of the roof side rail is joined to the upper surface of the side wall flange to form a hollow closed cross-section upper member, and the rear end of the upper member is the rear wall An automobile body structure is proposed in which a rear bumper beam is connected to a rear wall flange extending rearward from the upper end of the rear wall.

  According to the invention described in claim 2, in addition to the structure of claim 1, the front end of the upper member is connected to the rear end of the roof side rail via the upper end of the rear wall portion of the floor. A vehicle body structure characterized by this is proposed.

  According to the invention described in claim 3, in addition to the configuration of claim 1 or claim 2, a metal nut member is fixed to the connection portion of the side wall and the rear wall of the rear panel, and the nut member is fixed to the nut member. A vehicle body structure is proposed in which the rear bumper beam is fastened.

  According to a fourth aspect of the present invention, in addition to the configuration of the third aspect, a pair of upper and lower bottom walls at the front end of the rear bumper beam having a W-shaped cross section that opens rearward are bolted to the nut member. A vehicle body structure characterized by having been fastened at is proposed.

  According to the fifth aspect of the present invention, in addition to the configuration of the third or fourth aspect, the pair of bulging portions that bulge forward from both ends in the vehicle width direction of the rear wall of the rear panel. A vehicle body structure for an automobile is proposed in which the nut member is provided on the rear bumper beam and collars inserted at both ends in the vehicle width direction of the rear bumper beam are fastened to the nut member.

  According to a sixth aspect of the present invention, in addition to the configuration of any one of the first to fifth aspects, the side wall flange and the rear wall flange are integrally continuous. A vehicle body structure is proposed.

  According to the invention described in claim 7, in addition to the structure of any one of claims 1 to 6, a pair of left and right metal rear frames fixed to the rear wall portion of the floor, A pair of left and right shock absorbing members which are configured by a fiber-reinforced resin in a straight hollow closed cross section and extend rearward from the pair of left and right rear frames, and both ends in the vehicle width direction are connected to the rear ends of the pair of left and right shock absorbing members A vehicle body structure for an automobile is provided, which is provided with a cross member having a closed cross section.

  According to the invention described in claim 8, in addition to the structure of claim 7, the shock absorbing member includes a plurality of continuous fiber reinforced resin layers stacked, and the number of the continuous fiber reinforced resin layers stacked is A vehicle body structure is proposed in which the impact absorbing member decreases from the front to the rear.

  According to the ninth aspect of the present invention, in addition to the configuration of the eighth aspect, the number of the continuous fiber reinforced resin layers laminated at the rear end of the shock absorbing member is equal to the number of the layers adjacent to the front thereof. A vehicle body structure characterized by being larger than is proposed.

  According to the invention described in claim 10, in addition to the structure of any one of claims 7-9, a small cross-sectional area portion formed in a front portion of the shock absorbing member is formed in the rear frame. A vehicle body structure for an automobile characterized by being fitted and fixed in the formed recess is proposed.

  According to the invention described in claim 11, in addition to the configuration of any one of claims 7 to 10, the cross member includes an upper wall and a front wall on the lower wall and the rear wall of the rear panel. A L-shaped cross-section member made of fiber reinforced resin is combined to form a closed cross section, and a core material made of a corrugated sheet made of fiber reinforced resin is arranged inside the closed cross section. A vehicle body structure characterized by the above is proposed.

  According to the invention described in claim 12, the fiber reinforced resin rear panel connected to the rear of the fiber reinforced resin floor has at least a lower wall and left and right sides rising from both side edges in the vehicle width direction of the lower wall. A rear wall standing up from a rear edge of the lower wall, and a rear end of the roof side rail and the rear wall are connected by an upper member having a hollow closed cross section made of fiber reinforced resin, A vehicle body structure is proposed in which both ends of the rear bumper beam in the vehicle width direction are connected to the rear end.

  The crash rail 35 of the embodiment corresponds to the shock absorbing member of the present invention, the second rear panel 40 of the embodiment corresponds to the rear panel of the present invention, and the rear end cross member 42 of the embodiment corresponds to the cross of the present invention. Corresponds to member.

  According to the configuration of the first aspect, the fiber reinforced resin rear panel connected to the rear of the fiber reinforced resin floor has at least a lower wall, left and right side walls standing from both side edges in the vehicle width direction, and a lower wall. A fiber reinforced resin having a rear wall standing up from the rear edge of the wall, and provided with a side wall flange that is bent outward in the vehicle width direction and inclined rearward and downward at the upper ends of the left and right side walls, and connected to the rear end of the roof side rail An upper member having a hollow closed cross section is formed by joining a hat-shaped cross-section member made of a metal to the upper surface of the side wall flange, the rear end of the upper member is connected to a rear wall flange extending rearward from the upper end of the rear wall, and the rear wall is connected to the rear wall. Since the bumper beam is connected, the rear part of the vehicle body is made of fiber reinforced resin, so that it can not only improve the shock absorption performance while reducing the weight, but also the position of the front bumper beam of other vehicles that collide rearward Even if higher than the position of the Ya bumper beam, the inclination of the front of the rear wall of the rear panel by the collision load is suppressed by the upper member, it is possible to enhance the impact absorption effect by the rear bumper beam. Moreover, since it is not necessary to increase the position of the rear bumper beam, the degree of freedom in designing the rear part of the vehicle body is improved.

  According to the second aspect of the invention, since the front end of the upper member is connected to the rear end of the roof side rail via the upper end of the rear wall portion of the floor, the rigidity of the rear wall of the rear panel is increased by the rear wall portion of the floor. It is possible to prevent the rear panel from falling forward due to the collision load of the rear collision.

  According to the third aspect of the present invention, since the metal nut member is fixed to the connecting portion between the side wall and the rear wall of the rear panel and the rear bumper beam is fastened to the nut member, the rear bumper beam is easily and firmly fixed. be able to.

  According to the fourth aspect of the present invention, the pair of upper and lower bottom walls at the front end of the rear bumper beam having a W-shaped cross section that opens rearward is fastened to the nut member by bolts. By deforming the rear bumper beam of the cross section so as to open up and down, it is possible to prevent the rear bumper beam from falling down or up and losing the impact absorbing effect.

  According to the fifth aspect of the present invention, the nut member is provided on the pair of bulging portions that bulge forward from the vehicle width direction both ends of the rear wall of the rear panel, and the rear bumper beam is inserted at both the vehicle width direction both ends. Since the collar is fastened to the nut member, it is possible to secure a space for arranging the collar on the rear surface of the bulging portion and make the cross-sectional area of the rear bumper beam constant in the vehicle width direction.

  Further, according to the configuration of the sixth aspect, since the side wall flange and the rear wall flange are integrally continuous, it is possible to effectively prevent the rear wall from falling forward due to the collision load of the rear surface collision.

  According to the configuration of claim 7, the pair of left and right metal rear frames fixed to the rear wall portion of the floor, and the straight hollow closed cross section made of fiber reinforced resin, and rearward of the pair of left and right rear frames. A pair of left and right shock absorbing members extending in the direction of the vehicle, and a cross member having a closed cross-section with both ends in the vehicle width direction connected to the rear ends of the pair of left and right shock absorbing members. Sometimes, the collision load is reliably transmitted to the pair of left and right shock absorbing members via a high-strength cross member with a closed cross section. At this time, since the front ends of the pair of left and right shock absorbing members are made of metal and connected to a high-strength rear frame, the pair of left and right shock absorbing members are reliably crushed by supporting the collision load with the rear frame. The impact absorbing effect can be enhanced. Moreover, since the shock absorbing member is made of fiber reinforced resin, it is not only lighter than a metal shock absorbing member, but also increases the amount of shock absorption per unit length compared to a metal shock absorbing member. Thus, further reduction in weight can be achieved by shortening the longitudinal length of the shock absorbing member.

  According to the configuration of claim 8, the shock absorbing member includes a plurality of continuous fiber reinforced resin layers stacked, and the number of continuous fiber reinforced resin layers stacked decreases from the front to the rear of the shock absorbing member. When the impact load of the rear impact is input, the impact absorbing member can be sequentially crushed from the rear end side to enhance the impact absorbing effect.

  According to the ninth aspect of the present invention, since the number of continuous fiber reinforced resin layers laminated at the rear end of the shock absorbing member is larger than the number of laminated portions adjacent to the front thereof, the coupling between the shock absorbing member and the cross member The strength can be increased, and the impact absorbing member can be crushed from the rear end side in order to prevent the impact absorbing member from tilting when a rear collision collision load is input to the cross member, thereby enhancing the impact absorbing effect. .

  According to the structure of the tenth aspect, since the small cross-sectional area portion formed at the front portion of the shock absorbing member is fitted and fixed to the concave portion formed at the rear frame, the impact is applied when the collision load of the rear collision is input. While preventing the inclination of the absorbing member, the impact absorbing member can be crushed sequentially from the rear end side to enhance the impact absorbing effect.

  Further, according to the structure of claim 11, the cross member forms a closed cross-section portion by connecting the L-shaped cross-section member made of fiber reinforced resin having the upper wall and the front wall to the lower wall and the rear wall of the rear panel. In addition, since a core material made of a corrugated sheet made of fiber reinforced resin is arranged inside the closed cross section, not only can a high strength cross member be obtained while reducing the weight by reducing the thickness of the rear panel, Even if the rear wall of the rear panel has a curved shape, a cross member along the curved shape can be easily obtained.

  According to the structure of claim 12, the rear panel made of fiber reinforced resin connected to the rear of the floor made of fiber reinforced resin has at least a lower wall, and left and right side walls standing from both side edges in the vehicle width direction, A rear wall standing up from the rear edge of the lower wall, the rear end of the roof side rail and the rear wall are connected by an upper member of a hollow closed section made of fiber reinforced resin, and the rear bumper beam of the rear member is connected to the rear end of the upper member Since both ends in the vehicle width direction are connected, the rear part of the vehicle body is made of fiber reinforced resin, so that it can not only improve impact absorption performance while reducing the weight, but also the position of the front bumper beam of other vehicles that collide rearward is the rear bumper beam of the own vehicle Even when the position is higher than the position of, the upper member prevents the rear panel from falling forward due to a collision load, and the impact absorption effect of the rear bumper beam can be enhanced. That. Moreover, since it is not necessary to increase the position of the rear bumper beam, the degree of freedom in designing the rear part of the vehicle body is improved.

The perspective view of the frame of the body of a car. (First embodiment) The perspective view of the frame | skeleton of the vehicle body rear part of a motor vehicle. (First embodiment) FIG. 3 is a three-direction arrow view of FIG. 2. (First embodiment) FIG. 4 is a sectional view taken along line 4-4 of FIG. (First embodiment) The perspective view of a bumper beam extension. (First embodiment) FIG. 6 is an enlarged view of 6 parts in FIG. 4. (First embodiment) FIG. 7 is a cross-sectional view taken along line 7-7 in FIG. 3. (First embodiment) The figure corresponding to FIG. (Second Embodiment) The figure corresponding to FIG. (Third embodiment) 10A-10A line and 10B-10B line sectional drawing of FIG. (Third 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 FIGS. 1 and 2, the body frame of an automobile includes a floor 11 made of CFRP (carbon fiber reinforced resin). The floor 11 extends along the left and right edges of the floor panel portion 12, the front wall portion 13 rising from the front end of the floor panel portion 12, the rear wall portion 14 rising from the rear end of the floor panel portion 12, and the floor panel portion 12. A pair of left and right side sill portions 15, 15 extending in the front-rear direction, a pair of left and right front pillar lower portions 16, 16 extending from the front ends of the left and right side sill portions 15, 15 along the left and right edges of the front wall portion 13, A cross connecting the pair of left and right rear pillars 17 and 17 extending from the rear ends of the side sill parts 15 and 15 along the left and right side edges of the rear wall 14 and the upper ends of the left and right rear pillars 17 and 17 in the vehicle width direction. And a member portion 18.

  A pair of left and right damper housings 19, 19 made of aluminum alloy are fixed to the front surface of the front wall portion 13, and a pair of left and right front side frames 20, 20 are formed integrally with the damper housings 19, 19. A pair of left and right CFRP crash rails 21, 21 extend forward from the front ends of the front side frames 20, 20, and a CFRP rectangular frame shape is formed on the inner side in the vehicle width direction of the front ends of the left and right crash rails 21, 21. The front bulkhead 22 is supported. A pair of left and right CFRP bumper beam extensions 23, 23 are connected to the outer sides of the front ends of the left and right crash rails 21, 21, and CFRP extends in the vehicle width direction between the front ends of the left and right bumper beam extensions 23, 23. A made front bumper beam 24 is connected. A CFRP box-shaped shroud 25 opened in the front-rear direction is supported in a space surrounded by the left and right crash rails 21 and 21, the front bulkhead 22, the left and right bumper beam extensions 23 and 23, and the front bumper beam 24.

  A pair of left and right CFRP upper members 26, 26 extending forward from the upper ends of the left and right front pillar lower portions 16, 16 are connected to the outer surfaces in the vehicle width direction of the damper housings 19, 19 and forward from the front ends of the upper members 26, 26. The front ends of a pair of left and right CFRP lower members 27, 27 extending inward in the vehicle width direction are connected to the front bulkhead 22.

  The floor panel portion 12 of the floor 11 integrally includes a floor tunnel 28 that extends in the vehicle width direction center portion in the front-rear direction and connects the front wall portion 13 and the rear wall portion 14. Are connected by a cross member 29 made of CFRP extending in the vehicle width direction. A pair of left and right center pillars 30, 30 are erected from the front-rear direction intermediate portion of the left and right side sill portions 15, 15, and the upper ends of the left and right center pillars 30, 30 are connected by a roof arch 31 extending in the vehicle width direction. The

  The left and right center pillars 30 and 30 and the roof arch 31 are integrally formed of CFRP so as to form an inverted U shape when viewed from the front. The upper ends of the left and right front pillar lower portions 16, 16 and the upper ends of the left and right rear pillar portions 17, 17 are connected by front pillars 32, 32 and roof side rails 33, 33, which are integrally formed of CFRP and extend in the front-rear direction. .

  A pair of left and right rear frames 34, 34 made of aluminum alloy are connected to the rear surface of the rear wall portion 14 of the floor 11. A pair of left and right CFRP crash rails 35, 35 extend rearward from the lower ends of the left and right rear frames 34, 34, and a CFRP rear end cross extends in the vehicle width direction between the rear ends of the left and right crash rails 35, 35. A member 42 is connected, and a rear bumper beam 36 made of CFRP is fixed to the rear surface thereof. A pair of left and right CFRP connecting members 37, 37 are disposed between the upper ends of the left and right rear frames 34, 34 and the upper ends of the left and right rear pillar portions 17, 17. CFRP upper members 38, 38 extend rearward and downward and are connected to both ends of the rear bumper beam 36 in the vehicle width direction.

  The lower ends of the left and right rear frames 34, 34 are connected by a first CFRP rear panel 39 extending rearward from the rear end of the floor panel portion 12, and CFRP second rearward extending from the rear end of the first rear panel 39. Two rear panels 40 are connected to the lower surfaces of the left and right upper members 38, 38 and the front surface of the rear bumper beam 36.

  Next, the structure of the rear part of the vehicle body will be described in detail with reference to FIGS.

  As is apparent from FIG. 2, the rear frame 34 made of aluminum alloy has a plate-like side wall 34a extending in the front-rear direction and the vertical direction, and a bottom wall 34b bent inward in the vehicle width direction from the lower end of the side wall 34a. With. A damper housing 34c that is recessed inward in the vehicle width direction is integrally formed at the center of the side wall 34a.

  The front edge of the side wall 34a of the rear frame 34 is fastened to the rear surface of the rear wall 14 with a plurality of bolts 51. The bottom wall portion 34b of the rear frame 34 is formed in a box cross section, and the left and right side edges of the first rear panel 39 are fastened to the upper surface thereof by a plurality of bolts 52.

  As is apparent from FIGS. 3 to 5, the crash rail 35 is a member having a linear hollow cross section having a square cross section in which CFRP is laminated in a plurality of layers, and the number of laminated layers is 18 layers from the front end side toward the rear end side. 14 layers → 12 layers → 10 layers gradually decreasing, and only the rear end portion is locally increased from 10 layers to 12 layers. The front end of the crash rail 35 constitutes a small cross-sectional area 35a having a reduced cross-sectional area, and the small cross-sectional area 35a is a recess that opens at the rear end of the bottom wall 34b formed in the box cross section of the rear frame 34. 34d (see FIG. 4) is fitted and fixed from behind.

  The pair of left and right crash rails 35, 35 are arranged so as to be inclined so that the rear end side approaches the front end side, and are pulled rearward from the inner end in the vehicle width direction of the front end of each crash rail 35 in plan view. The straight line L (see FIG. 3) passes through the cross section of the rear end of the crash rail 35.

  The first rear panel 39 is configured by sandwiching a corrugated core material between upper and lower CFRP panels. The second rear panel 40 is configured by a single CFRP panel and extends in the horizontal direction. The lower wall 40a to which the lower surfaces of the crash rails 35, 35 are connected, a pair of side walls 40b, 40b that rises from the left and right side edges of the lower wall 40a, and the left and right side wall portions 40b that stand from the rear edge of the lower wall 40a, A rear wall 40c connecting the rear ends of 40b.

  As is apparent from FIG. 2, the upper end of the side wall 40b of the rear rear floor 40 is bent outward in the vehicle width direction to form a side wall flange 40d, and a pair of inner flanges 41a at the lower end of the hat-shaped cross section member 41 made of CFRP. By connecting the outer flange 41b to the upper surface of the side wall flange 40d, the side wall flange 40d and the hat-shaped cross-section member 41 constitute a hollow closed cross-section upper member 38. At this time, the rear flange 41c of the rear end of the hat-shaped cross-section member 41 is connected to the upper surface of the outer end in the vehicle width direction of the rear wall flange 40e of the second rear panel 40. The front end of the upper member 38 extending from the front upper side to the rear lower side is connected to the upper end of the rear wall portion 14 of the floor 11, that is, the rear end of the roof side rail 33 across both ends of the cross member 29 in the vehicle width direction.

  As apparent from FIGS. 4 and 6, the upper end of the rear wall 40c of the rear rear floor 40 is bent rearward to form a rear wall flange 40e, and both ends in the vehicle width direction of the rear wall flange 40e are left and right side walls. It continues to the rear ends of the flanges 40d, 40d. A rear end cross member 42 extending in the vehicle width direction along the front surface of the rear bumper beam 36 is configured by connecting an L-shaped cross-section member 53 made of CFRP and a rear rear floor 40.

  That is, the L-shaped cross-section member 53 is formed in an L-shaped cross section having a front wall 53a and an upper wall 53b, and a front wall flange 53c extending forward from the lower end of the front wall 53a is connected to the upper surface of the lower wall 40a of the rear panel 40. The upper wall flange 53d extending upward from the rear end of the upper wall 53b is connected to the front surface of the rear wall 40c of the rear panel 40. A corrugated core material 54 is disposed in a hollow cross section formed between the L-shaped cross-section member 53 and the rear panel 40.

  At this time, the upper end of the core member 54 is sandwiched between the rear wall 40 c of the rear panel 40 and the upper wall flange 53 d of the L-shaped cross-sectional member 53. A flange 35 b provided at the rear end of the crash rail 35 is connected to the front surface of the rear end cross member 42, that is, the front surface of the front wall 53 a of the L-shaped cross-section member 53.

  The crash rail 35, the L-shaped cross-section member 53, and the second rear panel 40 include a plurality of laminated continuous fiber reinforced resin layers, and the number of laminated second rear panels 40 is set to be the smallest of the number of laminated layers. The

  As apparent from FIGS. 4, 6 and 7, the CFRP rear bumper beam 36 has a pair of U-shaped cross-sections having an upper wall 55a, a lower wall 55b and a bottom wall 55c and opening rearward. Parts 55 and 55 are provided. A plurality of vertical ribs 55d that extend in the vertical direction and connect the upper wall 55a, the lower wall 55b, and the bottom wall 55c are formed in the U-shaped cross section 55, and both ends in the vehicle width direction are end walls. It is closed at 55e, 55e (see FIG. 2). Bosses 55f and 55f (see FIG. 7) project from the front surfaces of both ends of the U-shaped cross section 55 in the vehicle width direction, and metal collars 56 and 56 are inserted therein.

  A pair of bulging portions 40f and 40f (see FIGS. 3 and 4) bulging forward are formed at both ends in the vehicle width direction of the rear wall 40c of the rear panel 40, and the rear end cross member 42 has a pair of bulging portions. It is fixed so as to connect the bulging portions 40f, 40f. Two upper and lower metal nut members 57, 57 are inserted into a portion where the bulging portion 40f is connected to the side wall 40b. Upper and lower 2 penetrating through the bottom walls 55c and 55c of the upper and lower U-shaped cross sections 55 and 55 of the rear bumper beam 36, the collars 56 and 56 inserted into the bosses 55f and 55f, and the bulging portion 40f from the rear to the front. The end portions of the bumper beam 36 in the vehicle width direction are fixed to the rear surface of the rear end cross member 42 by screwing the bolts 58 and 58 into the upper and lower nut members 57 and 57.

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

  A pair of left and right metal rear frames 34, 34 are fixed to the rear part of the CFRP floor 11 of the automobile, and a pair of left and right crash rails 35, 35 having a straight CFRP hollow cross section are formed from the rear frames 34, 34. The rear end cross member 42, which extends rearward and has a closed cross section with CFRP, is fixed to the rear ends of the crash rails 35, 35, and the rear bumper beam 36 made of CFRP is fixed to the rear surface of the rear end cross member 42. As shown in FIG. 3, when a collision load of an offset rear surface collision is input to the rear bumper beam 36, the collision load is reliably applied to the pair of left and right crash rails 35 and 35 via the high-strength rear end cross member 42 in a closed cross section. Communicated. At this time, since the front ends of the crash rails 35 and 35 are made of metal and are connected to the high-strength rear frames 34 and 34, the crash rails 35 and 35 can be surely supported by supporting the collision load with the rear frames 34 and 34. The impact absorption effect can be enhanced by crushing. Moreover, since the crash rails 35 and 35 are made of CFRP, they are not only lighter than metal crash rails, but also increase the amount of shock absorption per unit length compared to metal crash rails. Further reduction in weight can be achieved by shortening the longitudinal length of the crash rails 35, 35.

  The rear end of the crash rails 35, 35 is biased inward in the vehicle width direction with respect to the front end, and the straight line L drawn rearward from the inner end in the vehicle width direction of the front end of the crash rails 35, 35 is a plan view. Since the cross section of the rear end (see FIG. 3), the distance between the rear ends of the pair of left and right crash rails 35, 35 is reduced, and when the collision load of the offset rear side collision biased to one side in the vehicle width direction is input, A collision load can be easily transmitted to the other crash rail 35 in the vehicle width direction, and the impact absorption effect can be enhanced.

  In particular, the crash rail 35 includes a plurality of continuous fiber reinforced resin layers laminated, and the number of continuous fiber reinforced resin layers stacked decreases from the front to the rear of the crash rail 35 (see FIG. 5). When the collision load is input, the crash rail 35 can be sequentially crushed from the rear end side to enhance the impact absorbing effect. At this time, the number of continuous fiber reinforced resin layers (12 layers) at the rear end of the crash rail 35 is larger than the number of layers adjacent to the front (10 layers). It is firmly coupled to the cross member 42, and the crash rail 35 is sequentially crushed from the rear end side while preventing the inclination of the crash rail 35 when a rear collision collision load is input to the rear end cross member 42. Can be increased.

  Further, since the small cross-sectional area 35a formed on the front portion of the crash rail 35 is fitted and fixed to the recess 34d formed on the rear frame 34 (see FIG. 4), the crash occurs when the collision load of the rear collision is input. While preventing the inclination of the front end portion of the rail 35, the crash rail 35 can be sequentially crushed from the rear end side to enhance the impact absorbing effect.

  In addition, the crash rails 35, 35, the L-shaped cross-section member 53, and the second rear panel 40 are provided with a plurality of laminated continuous fiber reinforced resin layers, thereby maximizing the shock absorbing performance at the time of rear collision while reducing the weight of the rear part of the vehicle body. In addition to securing the rear bumper beam 36 to the rear wall 40c of the rear floor panel 40 via the rear end cross member 42, the rear end cross member 42 receives the collision load of the rear collision input to the rear bumper beam 36. To the left and right crash rails 35, 35 and the second rear panel 40.

  In addition, the rear end cross member 42 is a closed cross-section formed by connecting a CFRP second rear panel 40 having a lower wall 40a and a rear wall 40c and a CFRP L-shaped cross-sectional member 53 having an upper wall 53b and a front wall 53a. Since the core material 54 made of a CFRP corrugated plate is arranged inside the closed cross section, the second end panel 40 is thinned to reduce the weight, while increasing the strength of the rear end cross member 42. In addition, even if the rear wall 40c of the second rear panel 40 has a curved shape, the rear end cross member 42 along the curved shape can be easily obtained.

  In addition, the crash rail 35, the L-shaped cross-sectional member 53, and the second rear panel 40 include a plurality of laminated continuous fiber reinforced resin layers, and the number of laminated second rear panels 40 is the smallest of the number of laminated layers. The weight of the rear part of the vehicle body can be reduced with reinforced resin, ensuring maximum shock absorption performance in the event of a rear collision.

  Further, when the rear bumper beam of the other vehicle collides with the upper rear surface of the rear bumper beam 36 of the own vehicle, the rear wall 40c of the second rear panel 40 to which the rear bumper beam 36 is fixed falls forward, and the crash rails 35, 35 There is a possibility that the impact absorbing effect by crushing may not be fully exhibited. However, according to the present embodiment, the hat-shaped cross-section members 41 and 41 are coupled to the upper surfaces of the side wall flanges 40d and 40d in which the upper ends of the left and right side walls 40b and 40b of the second rear panel 40 are bent outward in the vehicle width direction. The upper members 38, 38 having a hollow closed cross section are configured, and the rear ends of the upper members 38, 38 extending rearward and downward from the rear ends of the left and right roof side rails 33, 33 are rearward from the upper end of the rear wall 40c of the second rear panel 40. Since the rear bumper beam 36 is connected to the rear wall flange 40e extending to the rear wall 40c, the upper member 38, 38 prevents the rear wall 40c from falling forward due to a collision load by the upper members 38, 38, and The impact absorption effect by the bumper beam 36 can be enhanced. In addition, since it is not necessary to raise the position of the rear bumper beam 36 in order to prevent the rear wall 40c of the second rear panel 40 from falling forward, the degree of freedom in designing the rear part of the vehicle body is improved.

  In particular, since the front ends of the upper members 38, 38 are connected to the rear ends of the roof side rails 33, 33 via the upper ends of the rear wall portions 14 of the floor 11, the rigidity of the rear wall 40c of the second rear panel 40 is increased. The height of the rear wall 14 can be increased, and the rear wall 40c of the second rear panel 40 can be more reliably prevented from falling forward due to the collision load of the rear collision. At this time, since the side wall flanges 40d and 40d and the rear wall flange 40e of the second rear panel 40 are integrally continuous, the rigidity of the rear wall 40c is increased to further enhance the effect of preventing the rear wall 40c from collapsing due to the collision load of the rear surface collision. be able to.

  Further, since the metal nut members 57 are fixed to the connection portions of the side walls 40b, 40b and the rear wall 40c of the second rear panel 40 and the rear bumper beam 36 is fastened to the nut members 57, the rear bumper beam 36 can be easily and easily attached. It can be firmly fixed. At that time, the pair of upper and lower bottom walls 55c, 55c at the front end of the rear bumper beam 36 having a W-shaped cross section that opens rearward are fastened to the nut members 57 with bolts 58 ... By deforming the rear bumper beam 36 having a letter-shaped cross section so as to open up and down, it is possible to prevent the rear bumper beam 36 from falling upward or downward and not exhibiting the impact absorbing effect.

  Further, nut members 57 are provided in front of the pair of bulging portions 40f and 40f that bulge forward from both ends in the vehicle width direction of the rear wall 40c of the second rear panel 40, so that the rear bumper beam 36 extends in the vehicle width direction. Since the collars 56 inserted into the front bosses 55f at both ends are fastened to the nut members 57, a space for arranging the collars 56 on the rear surfaces of the bulging portions 40f, 40f is secured to cut off the rear bumper beam 36. The area can be made constant in the vehicle width direction.

Second embodiment

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

  In the first embodiment, the rear end cross member 42 is fixed to the front surface of the rear wall 40c of the second rear panel 40. However, in the second embodiment, the rear end is mounted on the rear surface of the rear wall 40c of the second rear panel 40. The cross member 42 is fixed. That is, an upper flange 59a and a lower flange 59b of a hat-shaped cross-section member 59 that opens forward to the rear surface of the rear wall 40c of the second rear panel 40 are connected to form a closed cross-section portion, and a corrugated plate is formed therein. The rear end cross member 42 is configured by arranging the core material 54. The rear bumper beam 36 is fixed to the rear surface of the hat-shaped cross-section member 59 of the rear end cross member 42 by means such as adhesion or rivet.

  According to the second embodiment, the rear end cross member 42 can be retrofitted to the second rear panel 40 to which the crash rails 35, 35 are connected in advance. Assembling of the bumper beam 36 is facilitated.

Third embodiment

  Next, a third embodiment of the present invention will be described based on FIG. 9 and FIG.

  The lower end of the upper member 38 of the first embodiment ends at the height of the upper end of the rear wall 40c of the second rear panel 40, but the upper member 38 of the third embodiment is rear of the second rear panel 40. The lower side wall 40b is bent in a heft shape along the rear edge from the upper edge of the side wall 40b, and the lower end thereof reaches the lower wall 40a of the second rear panel 40.

  That is, by connecting the upper flange 60a and the lower flange 60b of the hat-shaped cross-section member 60 that opens outward in the vehicle width direction along the upper edge and the rear edge of the inner surface in the vehicle width direction of the side wall 40b of the second rear panel 40, A U-shaped upper member 38 having a closed cross section is formed. Since the lower part of the upper member 38 that is bent in a letter-shape is connected to the front surface of the bulging portion 40f of the rear wall 40c of the second rear panel 40, the upper member 38 and the rear wall 40c of the second rear panel 40 are further strengthened. As a result, the rear wall 40c of the second rear panel 40 can be more reliably prevented from falling forward when a collision load of rear collision is input.

  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, each member is made of CFRP (carbon fiber reinforced resin), but may be another type of fiber reinforced resin such as glass fiber reinforced resin or aramid fiber reinforced resin.

11 Floor 14 Rear wall 33 Roof side rail 34 Rear frame 34d Recess 35 Crash rail (impact absorbing member)
35a Small sectional area 36 Rear bumper beam 38 Upper member 40 Second rear panel (rear panel)
40a lower wall 40b side wall 40c rear wall 40d side wall flange 40e rear wall flange 40f bulging portion 41 hat-shaped cross-section member 42 rear end cross member (cross member)
53 L-shaped cross-section member 53a Front wall 53b Top wall 54 Core material 55c Bottom wall 56 Collar 57 Nut member 58 Bolt

Claims (12)

  The rear panel (40) made of fiber reinforced resin connected to the rear of the floor (11) made of fiber reinforced resin has at least a lower wall (40a) and left and right sides rising from both side edges in the vehicle width direction of the lower wall (40a). A side wall (40b) and a rear wall (40c) rising from the rear edge of the lower wall (40a) are provided, and the upper ends of the left and right side walls (40b) are bent outward in the vehicle width direction and inclined rearward and downward. A side wall flange (40d) is provided, and a fiber-reinforced resin hat-shaped cross-section member (41) connected to the rear end of the roof side rail (33) is joined to the upper surface of the side wall flange (40d) to form a hollow closed cross section. An upper member (38) is formed, a rear end of the upper member (38) is connected to a rear wall flange (40e) extending rearward from an upper end of the rear wall (40c), and a rear bumper is connected to the rear wall (40e). beam( Body structure of a motor vehicle, characterized in that connecting a 6).   The front end of the upper member (38) is connected to the rear end of the roof side rail (33) via the upper end of the rear wall (14) of the floor (11). Vehicle body structure described.   A metal nut member (57) is fixed to a connection portion between the side wall (40b) and the rear wall (40c) of the rear panel (40), and the rear bumper beam (36) is fastened to the nut member (57). The vehicle body structure according to claim 1, wherein the vehicle body structure is a vehicle.   The pair of upper and lower bottom walls (55c) at the front end of the rear bumper beam (36) having a W-shaped cross section that opens rearward is fastened to the nut member (57) with bolts (58). Item 4. A vehicle body structure according to Item 3.   The nut member (57) is provided on a pair of bulging portions (40f) bulging forward from both ends in the vehicle width direction of the rear wall (40c) of the rear panel (40), and the rear bumper beam (36) The vehicle body structure according to claim 3 or 4, wherein collars (56) inserted at both ends in the vehicle width direction are fastened to the nut member (57).   The vehicle body structure according to any one of claims 1 to 5, wherein the side wall flange (40d) and the rear wall flange (40e) are integrally continuous.   A pair of left and right metal rear frames (34) fixed to the rear wall (14) of the floor (11), and a pair of left and right rear frames (i.e., a straight hollow closed section made of fiber reinforced resin). 34) and a pair of left and right shock absorbing members (35) extending rearward, and a cross-member (42) having a closed cross-section having both ends in the vehicle width direction connected to the rear ends of the pair of left and right shock absorbing members (35). The vehicle body structure according to claim 1, wherein the vehicle body structure is a vehicle body structure.   The shock absorbing member (35) includes a plurality of laminated continuous fiber reinforced resin layers, and the number of laminated continuous fiber reinforced resin layers decreases from the front to the rear of the shock absorbing member (35). The vehicle body structure according to claim 7, wherein the vehicle body structure is a feature.   The vehicle body structure of an automobile according to claim 8, wherein the number of laminated continuous fiber reinforced resin layers at the rear end of the shock absorbing member (35) is larger than the number of laminated portions adjacent to the front thereof. .   The small cross-sectional area portion (35a) formed at the front portion of the shock absorbing member (35) is fitted and fixed to a recess portion (34d) formed at the rear frame (34). The vehicle body structure of the automobile according to any one of claims 9 to 10.   The cross member (42) is an L-shaped cross-section member made of fiber reinforced resin having an upper wall (53b) and a front wall (53a) on the lower wall (40a) and the rear wall (40c) of the rear panel (40). 53) are combined to form a closed cross section, and a core material (54) made of a corrugated sheet made of fiber reinforced resin is arranged inside the closed cross section. The vehicle body structure according to any one of claims 10 to 10.   The rear panel (40) made of fiber reinforced resin connected to the rear part of the floor (11) made of fiber reinforced resin has at least a lower wall (40a) and left and right sides rising from both side edges in the vehicle width direction of the lower wall (40a). A side wall (40b) and a rear wall (40c) rising from the rear edge of the lower wall (40a) are provided, and the rear end of the roof side rail (33) and the rear wall (40c) are made of fiber reinforced resin. A vehicle body structure characterized in that the upper member (38) having a hollow closed cross section is connected, and both ends of the rear bumper beam (36) in the vehicle width direction are connected to the rear end of the upper member (38).

Images