JP2016010982A - Vehicle body front part structure of automobile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make compatible both the energy absorption performance of a bumper beam and that of a bumper beam extension.SOLUTION: Both ends in a vehicle width direction of a bumper beam in which a fiber-reinforced resin-made impact absorbing member 28 is connected to a front face of a steel-plate made bumper beam main body 27 are fixed to front ends of a pair of left and right fiber-reinforced resin-made bumper beam extensions 17 which extend in a fore-and-aft direction, a high-fragility impact absorbing member 28 is thereby reinforced by the high-extension bumper beam main body 27, and the bending rigidity of the bumper beam 18 is enhanced. Accordingly, when a collision load of front face collision is inputted to a center part of the bumper beam 18 in a vehicle width direction, the impact absorbing member 28 is firstly collapsed, and absorbs collision energy, and after that, collision loads are transmitted to front ends of the bumper beam extensions 17 as fore-and-aft loads while bending and warping the bumper beam main body 27 rearward, the bumper beam extensions 17 are collapsed to the fore-and-aft direction, and thus, collision energy can be absorbed.

Description

  The present invention relates to a vehicle body front structure in which both ends of a bumper beam in the vehicle width direction are fixed to front ends of a pair of left and right bumper beam extensions extending in the front-rear direction.

  A pair of left and right crash rails (bumper beam extension) that collapses and absorbs collision energy during a frontal collision of an automobile is made of carbon fiber reinforced resin in a hollow rectangular cross section, and its thickness gradually increases from the rear end to the front end. The thinned one is known from Patent Document 1 below.

  In addition, a pair of left and right crash boxes (bumper beam extensions) that collapse and absorb collision energy during a frontal collision of an automobile are configured with a carbon fiber reinforced resin in a wave-shaped cross section, and the rear end is made of an aluminum front side member (front side) The thing fastened via the joint member to the front-end part of a frame) is well-known by the following patent document 2. FIG.

  In addition, a pair of left and right load energy absorbers (bumper beam extension) that collapses and absorbs collision energy during a frontal collision of an automobile is constructed with a fiber reinforced resin in a wave-shaped cross section, and bumper reinforcement (bumper beam) Patent Document 3 below discloses that both ends in the vehicle width direction are fastened with bolts.

US Pat. No. 6,406,088 JP 2008-296823 A JP 2007-8283 A

  By the way, as described in Patent Document 3, both ends of the bumper beam in the vehicle width direction are coupled to the front ends of the pair of left and right bumper beam extensions, and when a collision load of frontal collision is input to the bumper beam. First, the bumper beam is deformed to absorb the collision energy, and then the bumper beam extension is crushed by the collision load transmitted from the bumper beam to absorb the collision energy.

  At this time, if the bumper beam is made of fiber reinforced resin, the bumper beam can be crushed by the collision load and absorb the collision energy, but the fiber reinforced resin bumper beam has low ductility and high brittleness. There is a possibility that it will bend backward at the part where a large bending moment is applied, and the collision load cannot be efficiently absorbed by effectively transmitting the collision load to the bumper beam extension.

  In addition, if the bumper beam extension is made of a steel plate with high ductility and low brittleness, the bumper beam will bend backward without bending, and the collision load will be transmitted to the bumper beam extension and the bumper beam extension will be reliably crushed to absorb the collision energy. However, there is a problem that the bumper beam itself cannot sufficiently exhibit the impact energy absorbing effect.

  The present invention has been made in view of the above circumstances, and an object thereof is to achieve both the energy absorption performance of the bumper beam and the bumper beam extension.

  In order to achieve the above object, according to the invention described in claim 1, both ends in the vehicle width direction of the bumper beam in which the shock absorbing member made of fiber reinforced resin is coupled to the front surface of the bumper beam main body made of steel plate, A vehicle body front structure is proposed, which is fixed to front ends of a pair of left and right fiber reinforced resin bumper beam extensions extending in the front-rear direction.

  According to the invention described in claim 2, in addition to the structure of claim 1, a front mounting member having an extension extending inward in the vehicle width direction is fixed to the front end of the bumper beam extension, and the bumper is fixed. An automobile body characterized in that the bumper beam body is fastened to the front surface of the extension part in a state where the outer end in the vehicle width direction of the beam body is positioned on the outer side in the vehicle width direction with respect to the center line of the bumper beam extension. A front structure is proposed.

  According to the invention described in claim 3, in addition to the configuration of claim 1 or 2, the bumper beam main body has a bottom wall, an upper wall, and a lower wall, and is open to the rear. A member having a U-shaped cross section, and the shock absorbing member is a member having a substantially V-shaped cross section having an upper wall and a lower wall and opening rearward, and is provided on the upper wall and the lower wall of the bumper beam body. There is proposed a vehicle body front structure in which an upper wall and a lower wall of the shock absorbing member are combined.

  According to a fourth aspect of the present invention, in addition to the configuration of the third aspect, the upper wall and the lower wall of the shock absorbing member include a plurality of beads extending in the front-rear direction. A front structure is proposed.

  According to the invention described in claim 5, in addition to the configuration of any one of claims 1 to 4, the outer end in the vehicle width direction of the shock absorbing member is connected to the bumper beam main body and the extension. An automobile body front structure characterized by being positioned in the vicinity of the fastening portion of the vehicle is proposed.

  According to the sixth aspect of the invention, in addition to the configuration of the second aspect, the bumper beam extension is a member having a hollow closed cross section, and is a closed cross section that protrudes rearward from the rear surface of the front mounting member. A front body structure of an automobile is proposed in which the front end portion of the bumper beam extension is fitted and fixed inside the rib.

  The upper horizontal rib 24b, the lower horizontal rib 24c, the vertical rib 24d, and the vertical rib 24e in the embodiment correspond to the ribs of the present invention.

  According to the configuration of the first aspect, the both ends of the bumper beam in the vehicle width direction, in which the shock absorbing member made of fiber reinforced resin is coupled to the front surface of the bumper beam main body made of steel plate, are made of a pair of left and right fiber reinforced resins extending in the front-rear direction. Since the bumper beam extension is fixed to the front end of the bumper beam extension, the impact absorbing member made of fiber reinforced resin having high brittleness is reinforced by the bumper beam main body made of steel plate having high ductility, and the bending rigidity of the bumper beam is increased. Therefore, when the collision load of the frontal collision is input to the central part in the vehicle width direction of the bumper beam, the impact absorbing member is first crushed and absorbs the collision energy, and then the bumper beam body is bent backward and the collision load is applied to the bumper beam extension. It is transmitted as a longitudinal load to the front end, and the bumper beam extension can be crushed in the longitudinal direction to absorb the collision energy. Thus, by combining the bumper beam body made of steel plate and the impact absorbing member made of fiber reinforced resin, the bumper beam can have both ductility and brittleness, and the impact energy absorption effect can be enhanced.

  According to the second aspect of the present invention, the front mounting member having an extension extending inward in the vehicle width direction is fixed to the front end portion of the bumper beam extension, and the outer end in the vehicle width direction of the bumper beam body is set at the center of the bumper beam extension. The bumper beam body is fastened to the front of the extension while being positioned outside the line in the vehicle width direction, so the front mounting member is strong so that the angle formed by the joint of the bumper beam and bumper beam extension does not change. By reinforcing the bumper beam extension, the bumper beam extension can be reliably crushed in the front-rear direction by applying a compressive load in the front-rear direction without applying a bending moment to the bumper beam extension.

  According to the configuration of claim 3, the bumper beam main body is a member having a bottom wall, an upper wall, and a lower wall and having a substantially U-shaped cross section that opens toward the rear, and the shock absorbing member includes the upper wall and the lower wall. It is a member with a substantially V-shaped cross section that has a wall and opens toward the rear, and the upper and lower walls of the shock absorbing member are joined to the upper and lower walls of the bumper beam body, so that the bumper beam is closed hollow. It is possible to enhance the energy absorption effect and increase the bending rigidity of the bumper beam to further improve the efficiency of transmitting the collision load to the bumper beam extension.

  According to the fourth aspect of the present invention, since the upper wall and the lower wall of the shock absorbing member are provided with a plurality of beads extending in the front-rear direction, the amount of energy absorbed at the time of a frontal collision can be increased.

  According to the fifth aspect of the present invention, since the outer end in the vehicle width direction of the shock absorbing member is positioned in the vicinity of the fastening portion of the bumper beam main body and the extension portion, the bumper beam extension is absorbed from the energy absorption due to the collapse of the shock absorbing member. The energy absorption effect is enhanced by smoothly switching to energy absorption by crushing.

  According to the sixth aspect of the present invention, the bumper beam extension is a member having a hollow closed cross section, and the front end portion of the bumper beam extension is fitted inside the rib of the closed cross section protruding rearward from the rear surface of the front mounting member. As a result, the bumper beam extension and the front mounting member can be easily positioned together, and the front mounting member is firmly connected to the bumper beam extension so that it does not tilt. Thus, the collision load can be more reliably transmitted from the bumper beam to the bumper beam extension.

The disassembled perspective view of the vehicle body front part of a motor vehicle. FIG. 2 is a two-direction arrow view of FIG. 1. FIG. 3 is a sectional view taken along line 3-3 in FIG. 2. FIG. 4 is a cross-sectional view taken along line 4-4 of FIG. FIG. FIG. 7A-7A line, 7B-7B line and 7C-7C line sectional view of FIG. FIG. The disassembled perspective view of a bumper beam extension, a rear attachment member, and a front attachment member.

  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. The input direction of the collision load is the front-rear direction.

  As shown in FIGS. 1 and 2, the cabin 11 made of fiber reinforced resin is integrally provided with a floor panel 12, a pair of left and right side sills 13, 13, a center tunnel 14, a dash panel 15, and the like. A pair of left and right metal front side frames 16, 16 extend forward from the front end of the cabin 11, and a pair of left and right fiber reinforced resin bumper beam extensions 17, 17 are connected to the front end. Both ends of the bumper beam 18 in the vehicle width direction are connected to the front ends of the left and right bumper beam extensions 17 and 17, and intermediate portions in the front-rear direction of the pair of left and right lower members 19 and 19 made of fiber reinforced resin are connected to the rear outer surface. Is done. Between the left and right bumper beam extensions 17, 17, a square frame-shaped front bulkhead 20 made of fiber reinforced resin is provided.

  As shown in FIG. 9, the bumper beam extension 17 is composed of an outer half body 21 positioned on the outer side in the vehicle width direction and an inner half body 22 positioned on the inner side in the vehicle width direction, and members having hat-shaped cross sections that are plane-symmetric with each other. The outer half 21 and the inner half 22 are provided with side walls 21a, 22a, upper walls 21b, 22b, lower walls 21c, 22c, upper joining flanges 21d, 22d and lower joining flanges 21e, 22e, respectively. The joining flanges 21d and 22d and the lower joining flanges 21e and 22 are joined by bonding. The bumper beam extension 17 is tapered so that its cross-sectional area decreases from the rear to the front, but the wall thickness is uniformly formed as a whole.

  The rear mounting member 23 coupled to the rear end of the bumper beam extension 17 includes an upper lateral rib 23b and a lower lateral rib 23c extending forward from an upper edge and a lower edge of the rectangular plate-shaped main body 23a, and an upper lateral rib 23b and a lower part. A pair of left and right vertical ribs 23d and 23e extending in the vertical direction so as to connect the horizontal ribs 23c, and six intermediate horizontal ribs 23f extending in the left and right direction from the pair of left and right vertical ribs 23d and 23e are provided. The upper horizontal rib 23b, the lower horizontal rib 23c and the pair of left and right vertical ribs 23d and 23e form a cylindrical closed cross section, and are fitted so that the outer peripheral surface of the rear end of the bumper beam extension 17 is in close contact with the inner peripheral surface thereof. Fixed by bonding.

  The front mounting member 24 is a member having a shape similar to that of the rear mounting member 23 described above, and includes an upper lateral rib 24b and a lower lateral rib 24c that extend forward from the upper edge and the lower edge of the rectangular plate-shaped main body portion 24a. , A pair of left and right vertical ribs 24d, 24e extending in the vertical direction so as to connect the upper horizontal rib 24b and the lower horizontal rib 24c, four intermediate horizontal ribs 24f extending in the left-right direction from the pair of left and right vertical ribs 24d, 24e,. With. The upper horizontal rib 24b, the lower horizontal rib 24c, and the pair of left and right vertical ribs 24d and 24e constitute a cylindrical closed cross section, and are fitted so that the outer peripheral surface of the front end of the bumper beam extension 17 is in close contact with the inner peripheral surface thereof. It is fixed by bonding.

  At this time, the upper joint flanges 21d and 22d and the lower joint flanges 21e and 22 of the bumper beam extension 17 have stepped portions a and b (see FIGS. 4 and 9), which are in front of the stepped portions a and b. Only the portion fits into the cylindrical closed cross section, so that the rear edges of the upper lateral rib 24b and the lower lateral rib 24c are opposed to the front edges of the step portions a and b. Further, the front mounting member 24 is asymmetrical with respect to the center line L of the bumper beam 17, and the inner portion in the vehicle width direction of the main body portion 24a is longer than the outer portion in the vehicle width direction by the extension portion 24g ( FIG. 8 and FIG. 9).

  The bumper beam extension 17, the rear mounting member 23, and the front mounting member 24 integrated in this way are formed by four bolts 26 at the front end of a rectangular mounting plate 25 welded to the front end of the front side frame 16. It is concluded.

  As shown in FIGS. 2, 4 and 8, the bumper beam 18 includes a bumper beam main body 27 made of a steel plate and an impact absorbing member 28 made of fiber reinforced resin. The bumper beam body 27 is a hat-shaped cross-section member that has a bottom wall 27a, an upper wall 27b, a lower wall 27c, an upper flange 27d, and a lower flange 27e, and opens rearward. Curved in an arc so as to protrude forward. The outer end portion in the vehicle width direction of the bumper beam main body 27 is fastened to an extension portion 24g obtained by extending the main body portion 24a of the front mounting member 24 inward in the vehicle width direction with two bolts 29 and 29, respectively. In this state, the outer end in the vehicle width direction of the bumper beam body 27 protrudes outward in the vehicle width direction from the center line L of the bumper beam extension 17 (see FIG. 8).

  The shock absorbing member 28 covering the front surface of the bumper beam main body 27 is a member having a V-shaped cross section having an upper wall 28a and a lower wall 28b, and the upper wall 28a and the lower wall 28b are respectively the upper wall 27b of the bumper beam main body 27. And it fixes to the lower wall 27c by adhesion | attachment. A large number of beads 28c... Extending in the front-rear direction are formed on the upper wall 28a and the lower wall 28b of the shock absorbing member 28. In the state where the shock absorbing member 28 is coupled to the bumper beam main body 27, both form a hollow closed cross section, and the outer end in the vehicle width direction of the shock absorbing member 28 fastens the bumper beam main body 27 to the front mounting member 24. It is located in the vicinity of the bolts 29, 29 (see FIG. 8).

  As shown in FIGS. 1, 2, and 7 (B), a front bulk made of fiber reinforced resin is formed on the inner surfaces in the vehicle width direction of the side walls 22 a and 22 a of the inner halves 22 and 22 of the left and right bumper beam extensions 17 and 17. The front bulkhead 20 made of fiber reinforced resin is supported via the head support members 30 and 30. The front bulkhead 20 has a lower beam 32a and a pair of left and right side beams 32b and 32b, and is integrally formed with a pair of left and right upper members 33a and 33a at left and right upper ends of a lower member 32 that curves in a U shape in a front view. The upper beam 33b of the upper member 33 that is formed and curved in a U shape in plan view is coupled to form a rectangular frame shape, and the pair of left and right side beams 32b and 32b of the lower member 32 are formed on the front bulkhead support member 30. , 30.

  As shown in FIGS. 1 to 3, 5, 6, and 7C, fibers are formed on the outer surfaces in the vehicle width direction of the side walls 21a and 21a of the outer halves 21 and 21 of the left and right bumper beam extensions 17 and 17. The intermediate portions in the front-rear direction of the lower members 19, 19 made of fiber reinforced resin are supported via the lower member support members 34, 34 made of reinforced resin. An inner portion of the lower member support member 34 is formed in a U-shaped cross section that includes a bottom wall 34a, an upper wall 34b, and a lower wall 34c, and is open rearward. An inner side wall 34e covering the inner end in the width direction is bonded to the side walls 21a and 21a of the outer half bodies 21 and 21. The outer part of the inner part of the lower member support member 34 that extends to the outer side in the vehicle width direction is formed with an L-shaped cross section including an outer wall 34f and a front wall 34g, and the front wall 19a and the side wall 19b of the lower member 19 are bonded thereto. (See FIG. 7C).

  The rear ends of the upper wall 34b and the lower wall 34c that extend rearward of the lower member support member 34 are opposed to the front ends of the upper lateral rib 23b and lower lateral rib 23c that extend forward of the rear mounting member 23. The upper wall 34 b extending rearward of the support member 34 is positioned slightly above the upper lateral rib 23 b of the rear mounting member 23, and the lower wall 34 c extending rearward of the lower member support member 34 is the lower lateral rib 23 c of the rear mounting member 23. It is located slightly below. The thickness t1 of the front bulkhead support members 30 and 30 positioned on the front side is thinner than the thickness t2 of the lower member support members 34 and 34 positioned on the rear side (see FIG. 7A).

  As shown in FIGS. 1 and 5, the front ends of the lower members 19, 19 that curve forward and downward and the left and right corners of the lower member 32 of the front bulkhead 20 are connected by connecting members 35, 35 made of fiber reinforced resin. Is done.

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

  When the vehicle collides with the front and a collision load is input to the bumper beam 18, first, the impact absorbing member 28 made of fiber reinforced resin on the front side of the bumper beam 18 is crushed and absorbs the collision energy.

  Subsequently, the collision load is transmitted to the bumper beam main body 27 on the rear surface side of the bumper beam 18, and is made of a steel plate having a bottom wall 27a, an upper wall 27b, and a lower wall 27c and having a U-shaped cross section. Since the bumper beam body 27 has high ductility, the bumper beam body 27 does not bend only by bending backward in an arc shape, and effectively transmits a collision load from both ends in the vehicle width direction to the left and right bumper beam extensions 17, 17. The bumper beam extensions 17 and 17 can be crushed in the front-rear direction to absorb energy. At this time, the thickness of the bumper beam extension 17 is uniform from the front to the rear, and the sectional area of the closed cross section of the bumper beam extension 17 increases from the front to the rear (see FIG. 7). The bumper beam extension 17 can be sequentially crushed from the low-strength front end side to the high-strength rear end side by the load, thereby improving the shock absorbing performance.

  In addition, the bumper beam main body 27 is a member having a U-shaped cross section having a bottom wall 27a, an upper wall 27b, and a lower wall 27c and opening rearward. The shock absorbing member 28 has an upper wall 28a and a lower wall 28b. Since the upper wall 28b and the lower wall 28b of the shock absorbing member 28 are coupled to the upper wall 27b and the lower wall 27c of the bumper beam main body 27 (see FIG. 4). ), The bumper beam 18 can be formed in a hollow closed cross section to enhance the energy absorption effect, and the bending rigidity of the bumper beam 18 can be increased to further increase the efficiency of transmitting the collision load to the bumper beam extensions 17 and 17.

  At this time, since the beads 28c... Extending in the front-rear direction are formed on the upper wall 28a and the lower wall 28b of the impact absorbing member 28, the amount of energy absorbed by the collapse of the impact absorbing member 28 can be increased.

  If the bumper beam 18 is composed only of the fiber reinforced resin impact absorbing member 28, the impact absorbing member 28 is easily bent by the collision load, and the collision load is applied to the left and right bumper beam extensions 17, 17. There is a possibility that the energy cannot be efficiently transmitted and the energy absorption due to the collapse of the bumper beam extensions 17 and 17 is not sufficiently performed. If the bumper beam 18 is composed only of a bumper beam body 27 made of a steel plate, it is possible to transmit a collision load to the bumper beam extensions 17 and 17, but the bumper beam 18 itself has a collision energy. Since the absorption effect is not exhibited, there is a possibility that the collision energy absorption performance as a whole is lowered.

  On the other hand, according to the present embodiment, the bumper beam body 27 and the impact absorbing member 28 are combined to form the bumper beam 18, so that the bumper beam 18 itself exerts an impact energy absorbing effect while the bumper beam 18 is exerted. The extensions 17 and 17 can be reliably crushed to enhance the impact energy absorption effect.

  A front mounting member 24 having an extension 24g extending inward in the vehicle width direction is fixed to the front end portion of the bumper beam extension 17, and the outer end in the vehicle width direction of the bumper beam main body 27 is positioned more than the center line L of the bumper beam extension 17. Since the bumper beam main body 27 is fastened to the front surface of the extension 24g with bolts 29 and 29 (see FIG. 8) while being positioned outside in the vehicle width direction, the angle formed by the joint of the bumper beam 18 and the bumper beam extension 17 By firmly reinforcing the front mounting member 24 so as not to change, a compressive load in the front-rear direction is applied to the bumper beam extension 17 without applying a bending moment, and the bumper beam extension 17 is reliably crushed in the front-rear direction. can do.

  Further, since the outer end in the vehicle width direction of the impact absorbing member 28 is positioned in the vicinity of the fastening portion of the bumper beam main body 27 and the extension 24g by the bolts 29 and 29 (see FIG. 8), the energy by the collapse of the impact absorbing member 28 is obtained. The energy absorption effect is enhanced by smoothly switching from absorption to energy absorption by crushing the bumper beam extensions 17 and 17.

  Further, the bumper beam extension 17 is a member having a hollow closed cross section, and the front end of the bumper beam extension 17 is provided inside the upper lateral rib 24b, the lower lateral rib 24c, and the longitudinal ribs 24d and 24e protruding rearward from the rear surface of the front mounting member 24. Since the portions are fitted and fixed (see FIG. 9), the bumper beam extension 17 and the front mounting member 24 can be easily positioned, and the front of the bumper beam extension 17 can be easily fixed. By firmly coupling so that the part mounting member 24 does not tilt, it is possible to more reliably transmit the collision load from the bumper beam 18 to the bumper beam extension 17.

  Further, the upper lateral rib 24b and the lower lateral rib 24c of the front mounting member 24 made of fiber reinforced resin are in contact with the step portions a and b at the front ends of the upper joint flanges 21d and 22d and the lower joint flanges 21e and 22e of the bumper beam extension 17. Since they face each other so as to come into contact (see FIG. 4), when the collision load of the frontal collision is input from the bumper beam 18 to the front mounting member 24, the upper horizontal rib 24b and the lower horizontal rib 24c of the front mounting member 24 retreating. The energy absorbing effect can be exerted by biting into the step portions a and b at the front ends of the upper joint flanges 21d and 22d and the lower joint flanges 21e and 22e of the bumper beam extension.

  The bumper beam extension 17 has a hollow closed cross section formed by connecting upper joint flanges 21d and 22d and lower joint flanges 21e and 22e of the outer half body 21 and the inner half body 22 having a pair of left and right hat-shaped cross sections. The rear support member 23 fastened to the plate 25 includes an upper horizontal rib 23b, a lower horizontal rib 23c, and vertical ribs 23d and 23e protruding forward, and the rear end portion of the bumper beam extension 17 is used as the upper horizontal rib of the rear support member 23. 23b, lower horizontal rib 23c and vertical ribs 23d and 23e are fitted and fixed to the inner periphery (see FIG. 9), so that the rear end of the bumper beam extension 17 is firmly attached to the rear mounting member 23 with a light and simple structure. The bumper beam extension 17 is supported by the impact load of the frontal collision. When the bumper beam extension 17 is prevented from tilting from the front-rear direction when pressed against the mounting plate 25 at the front end portion of the front side frame 16, the entire bumper beam extension 17 is surely crushed and the amount of energy absorbed Can be increased.

  Further, a lower member support member 34 made of fiber reinforced resin is fixed to the outer surface of the bumper beam extension 17 in the vehicle width direction. The lower member support member 34 has a bottom wall 34a, an upper wall 34b, and a lower wall 34c and is opened rearward. And an outer portion of an L-shaped cross section having a front wall 34g and an outer wall 34f and fixed to the lower member 19 (see FIGS. 3 and 5 to 7). The lower member support member 34 and the lower member 19 can be crushed by the collision load of the frontal collision transmitted from the bumper beam extension 17 to exhibit an energy absorption effect.

  The rear support member 23 of the bumper beam extension 17 has a main body portion 23a, an upper lateral rib 23b, and a lower lateral rib 23c. The lower support member 23 is formed in a U-shaped cross section that opens toward the front and opens toward the rear. Since the opening of the support member 34 fits inside the opening of the rear support member 23 (see FIG. 3), when the collision load of the frontal collision is input to the lower member support member 34, the opening of the lower member support member 34 However, it is possible to exert an energy absorption effect by fitting inside the opening of the rear mounting member 23.

  The bumper beam extension 17 includes a thin front bulkhead support member 30 located on the front side and a thick lower member support member 34 located on the rear side, so that the strength of the bumper beam extension 17 changes from the front side to the rear side. As a result, the bumper beam extension 17 is sequentially crushed from the front end side by the collision load of the frontal collision, thereby enhancing the energy absorption effect.

  The front bulkhead 20 includes an upper beam 33b at the center in the vehicle width direction of the substantially U-shaped upper member 33 that opens rearward in a plan view, and a substantially U-shaped lower portion that opens upward in a front view. The member 32 is coupled to form a rectangular frame shape when viewed from the front, and the corners on both sides in the vehicle width direction of the lower member 32 and the front end portions of the lower members 19 and 19 are connected to the connecting members 35 and 35 made of fiber reinforced resin. 1 and the collision load transmitted from the bumper beam extensions 17 and 17 to the front bulkhead 20 is distributed to the lower members 19 and 19 through the connecting members 35 and 35 and effectively absorbed. be able to.

  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.

17 Bumper beam extension 18 Bumper beam 24 Front mounting member 24b Upper lateral rib (rib)
24c Lower lateral rib (rib)
24d Vertical rib (rib)
24e Vertical rib (rib)
24g Extension 27 Bumper beam main body 27a Bottom wall 27b Upper wall 27c Lower wall 28 Shock absorbing member 28a Upper wall 28b Lower wall 28c Bead L Center line of bumper beam extension

Claims (6)

  A pair of left and right fiber reinforced resins extending in the front-rear direction at both ends in the vehicle width direction of the bumper beam (18) in which a shock absorbing member (28) made of fiber reinforced resin is coupled to the front surface of a bumper beam body (27) made of steel plate A vehicle body front structure, which is fixed to the front end of a bumper beam extension (17).   A front mounting member (24) having an extension (24g) extending inward in the vehicle width direction is fixed to the front end of the bumper beam extension (17), and the outer end in the vehicle width direction of the bumper beam body (27) is The bumper beam main body (27) is fastened to the front surface of the extension portion (24g) in a state of being positioned on the outer side in the vehicle width direction from the center line (L) of the bumper beam extension (17). The vehicle body front part structure according to claim 1.   The bumper beam body (27) is a member having a bottom wall (27a), an upper wall (27b), and a lower wall (27c) and having a substantially U-shaped cross section that opens rearward, and the shock absorbing member ( 28) is a member having a substantially V-shaped cross section having an upper wall (28a) and a lower wall (28b) and opening rearward, and the upper wall (27b) and the lower wall of the bumper beam body (27). The vehicle body front part structure according to claim 1 or 2, wherein an upper wall (28a) and a lower wall (28b) of the shock absorbing member (28) are coupled to (27c).   The vehicle body front structure according to claim 3, wherein the upper wall (28a) and the lower wall (28b) of the shock absorbing member (28) include a plurality of beads (28c) extending in the front-rear direction. .   The outer end in the vehicle width direction of the shock absorbing member (28) is positioned in the vicinity of a fastening portion of the bumper beam main body (27) and the extension portion (24g). 5. The vehicle body front structure according to any one of 4 above.   The bumper beam extension (17) is a member having a hollow closed cross section, and the bumper beam extension (17) is disposed inside a rib (24b, 24c, 24d, 24e) having a closed cross section projecting rearward from the rear surface of the front mounting member (24). The vehicle body front structure according to claim 2, wherein the front end of the beam extension (17) is fitted and fixed.

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