JP2014124956A - Vehicular body structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To exhibit stable impact absorbing performance regardless of the input direction of an impact load to be input, while reducing the weight of a bumper beam extension.SOLUTION: Because a bumper beam extension 18 arranged between a vehicle body frame 14 and a bumper beam 19 is FRP-made, weight reduction compared with a steel-plate-made bumper beam extension is achieved. And, as the bumper beam extension 18 comprises integrally a main impact absorbing part 18a on an inner side in the vehicular width direction and sub impact absorbing parts 18b, 18c on an outer side in the vehicular width direction, and the main impact absorbing part 18a is arranged along the front-and-rear direction and the sub impact absorbing parts 18b, 18c are arranged so that the outer side in the front-and-rear direction is inclined to the outer side in the vehicular width direction, then, an impact load of a head-on collision or a rear end collision is received in the axial line direction of the main impact absorbing part 18a, to exhibit sufficient impact absorbing performance, and an impact load of an oblique collision is received in the axial direction of the sub impact absorbing parts 18b, 18c, to exhibit sufficient impact absorbing performance.

Description

  The present invention relates to an automobile body structure in which a bumper beam extension made of FRP is disposed between a body frame extending in the front-rear direction and a bumper beam extending in the vehicle width direction.

  An inner bumper beam extension and an outer bumper beam extension made of steel plate bent into a polygonal cylinder are arranged between the bumper beam and the connecting plate, and the inner bumper beam extension is curved forward from the vehicle width direction inner side to the vehicle width direction outer side. Patent Document 1 below discloses a curved shape that efficiently collapses the inner bumper beam extension when a collision load of an oblique collision is input to the bumper beam to enhance the impact absorption effect.

JP 2012-35703 A

  However, the one described in Patent Document 1 not only increases the weight because the bumper beam extension is made of a steel plate, but the curved inner bumper beam extension is not applied when a large collision load of frontal collision is input. There was a possibility that the inner bumper beam extension could not be crushed in the axial direction due to falling outside in the vehicle width direction and sufficient shock absorbing performance could not be demonstrated.

  The present invention has been made in view of the above-described circumstances, and an object thereof is to exhibit stable shock absorbing performance regardless of the input direction of the collision load while reducing the weight of the bumper beam extension.

  To achieve the above object, according to the first aspect of the present invention, an automobile in which a bumper beam extension made of FRP is disposed between a vehicle body frame disposed in the front-rear direction and a bumper beam disposed in the vehicle width direction. The bumper beam extension is integrally provided with a main shock absorbing portion on the inner side in the vehicle width direction and a sub impact absorbing portion on the outer side in the vehicle width direction, and the main shock absorbing portion is arranged along the front-rear direction. A vehicle body structure is proposed in which the sub-impact absorber is arranged such that the outer side in the front-rear direction is inclined outward in the vehicle width direction.

  According to the second aspect of the present invention, in addition to the configuration of the first aspect, the outer end in the front-rear direction of the bumper beam extension is inclined inward in the front-rear direction from the inner side in the vehicle width direction toward the outer side in the vehicle width direction. A vehicle body structure is proposed which is characterized by

  According to the invention described in claim 3, in addition to the configuration of claim 1 or claim 2, the front-rear inner end extending in the vehicle width direction of the bumper beam extension is the outer end in the front-rear direction of the body frame. It is attached via a mounting plate, the main impact absorbing portion is connected to the outer end in the front-rear direction of the body frame in a straight line shape, and the sub impact absorbing portion is connected to the side surface of the body frame via a brace member. A vehicle body structure characterized by the above is proposed.

  According to a fourth aspect of the present invention, in addition to the configuration of any one of the first to third aspects, the bumper beam extension is configured by combining an upper member and a lower member, and the upper portion The member and the lower member include an inner layer in which continuous fibers oriented in the front-rear direction and continuous fibers oriented in the vehicle width direction or in the up-down direction are consolidated with a resin, and an outer layer in which discontinuous fibers are consolidated with a resin. A vehicle body structure characterized by the above is proposed.

  According to the invention described in claim 5, in addition to the configuration of claim 4, the outer layer includes ribs extending along the axes of the main impact absorbing portion and the secondary impact absorbing portion. A car body structure is proposed.

  According to a sixth aspect of the present invention, in addition to the configuration of the fourth or fifth aspect, the outer layer is a flange that is bent in a direction that intersects the input direction of the collision load of the bumper beam extension. A vehicle body structure characterized by comprising:

  According to the invention described in claim 7, in addition to the configuration of any one of claims 1 to 6, the bumper beam extension is coupled to the pair of main impact absorbing portions to form a closed cross section. There is proposed a vehicle body structure comprising a main closed cross-sectional portion configured as described above and a sub closed cross-sectional portion configured by combining a pair of sub impact absorbing portions into a closed cross section.

  The front side frame front portion 14 of the embodiment corresponds to the vehicle body frame of the present invention, and the first sub impact absorbing portion 18b and the second sub impact absorbing portion 18c of the embodiment are included in the sub impact absorbing portion of the present invention. Correspondingly, the first sub-closed section 23 and the second sub-closed section 24 of the embodiment correspond to the sub-closed section of the present invention, and the front fastening flanges 51b and 51b of the embodiment are the flanges of the present invention. The second reinforcing ribs 51i and 52i of the embodiment correspond to the ribs of the present invention.

  According to the configuration of the first aspect, since the bumper beam extension disposed between the body frame and the bumper beam is made of FRP, the weight can be reduced as compared with the bumper beam extension made of steel plate. Moreover, the bumper beam extension is integrally provided with a main shock absorbing portion on the inner side in the vehicle width direction and a sub impact absorbing portion on the outer side in the vehicle width direction, the main shock absorbing portion is arranged along the front-rear direction, Since the front and rear direction outside is arranged to incline to the vehicle width direction outside, the impact load of frontal collision or rear collision is received in the axial direction of the main shock absorbing part, and sufficient shock absorbing part performance is exhibited, and oblique collision The impact load can be received in the axial direction of the secondary impact absorbing portion, and sufficient impact absorbing portion performance can be exhibited.

  According to the second aspect of the present invention, the outer end in the front-rear direction of the bumper beam extension is inclined inward in the front-rear direction from the inner side in the vehicle width direction toward the outer side in the vehicle width direction, so that the corner of the vehicle body is rounded. Contact with an obstacle in a narrow place can be avoided.

  According to the third aspect of the invention, the front / rear inner end of the bumper beam extension extending in the vehicle width direction is attached to the front / rear outer end of the vehicle body frame via the attachment plate, and the main shock absorber is disposed in the front / rear direction of the vehicle body frame. Since it is connected to the outer end in a straight line and the secondary impact absorbing part is connected to the side of the body frame via a brace member, the collision load of the frontal collision or rearal collision is applied to the vehicle body via the main impact absorbing part of the bumper beam extension. By transmitting the oblique collision load to the vehicle body frame via the bumper beam extension sub-impact absorption part and brace member, the effective shock absorption performance for various directions of collision load is exhibited. Can do.

  According to the fourth aspect of the present invention, the bumper beam extension is configured by connecting the upper member and the lower member, and the upper member and the lower member are aligned with the continuous fiber oriented in the front-rear direction and the vehicle width direction or the vertical direction. An upper layer and a lower member which are integrally provided with a main impact absorbing portion and a sub impact absorbing portion having different axial directions, since the inner layer is formed by solidifying the continuous fibers with resin and the outer layer is formed by discontinuous fibers being solidified with resin. In addition to being able to mold easily, by laminating a high-strength inner layer and a low-strength outer layer, the fiber and resin are successively broken from the end side where the collision load is input, resulting in a shock absorption amount Can be increased.

  According to the configuration of claim 5, the outer layer includes ribs extending along the axes of the main impact absorbing portion and the secondary impact absorbing portion. Therefore, the rib can be easily formed with discontinuous fibers having high formability. Thus, delamination of the continuous fibers in the inner layer can be suppressed to improve the shock absorbing performance.

  According to the configuration of claim 6, since the outer layer is provided with a flange bent in a direction intersecting the input direction of the bumper beam extension collision load, when the collision load is input from the bumper beam to the bumper beam extension. The shock absorbing performance can be enhanced by the flange having a large pressure receiving area being triggered (triggering to cause destruction) and the bumper beam extension being sequentially crushed in the front-rear direction.

  According to the configuration of claim 7, the bumper beam extension includes a main closed cross-sectional portion configured by combining a pair of the main impact absorbing portions to form a closed cross-section, and a pair of the sub-impact absorbing portions combined. Therefore, the shock absorbing performance can be enhanced by reducing the opening of the main impact absorbing portion and the sub impact absorbing portion by closing the main impact absorbing portion and the sub impact absorbing portion.

The perspective view of the vehicle body front part of a motor vehicle. FIG. 2 is a two-direction arrow view of FIG. 1. The perspective view of a bumper beam. 4 is an enlarged view of part 4 in FIG. FIG. FIG. 6 is a sectional view taken along line 6-6 of FIG. FIG. 7 is a cross-sectional view taken along line 7-7 of FIG. The exploded perspective view of a bumper beam extension. 9 (A)-9 (D) direction arrow directional view of FIG. Explanatory drawing of the manufacturing method of a bumper beam extension. Action | operation explanatory drawing at the time of the input of a collision load. Action | operation explanatory drawing at the time of the input of a collision load. Action | operation explanatory drawing at the time of the input of a collision load.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. In the present specification, the front-rear direction (impact load input direction), the left-right direction (vehicle width direction), and the up-down direction are defined with reference to the passenger seated in the driver's seat.

  As shown in FIGS. 1 and 2, the vehicle body of the embodiment includes a cabin 11 integrally formed in a bathtub shape with FRP such as CFRP (carbon fiber reinforced resin), and a dash panel 12 standing from its front end. A pair of left and right suspension support members 13, 13 that are die-cast with an aluminum alloy are fixed to the front surface. The suspension support members 13 and 13 include damper housings 13a and 13a that support upper ends of suspension dampers (not shown), and front side frame rear portions 13b and 13b that are connected to lower portions of the damper housings 13a and 13a and extend forward. A pair of left and right front side frame front parts 14, 14 made of an aluminum extruded material or a steel plate press material are connected to the front ends of the front side frame rear parts 13b, 13b. A pair of left and right FRP side members 16, 16 are connected to front ends of a pair of left and right FRP upper members 15, 15 extending forward from the left and right upper portions of the dash panel 12.

  A front bulkhead 17 made of FRP formed in a rectangular frame shape in front view is fixed to the front ends of the front side frame front portions 14, 14, and the front ends of the side members 16, 16 are located on the upper left and right sides of the front bulkhead 17. Connected. A pair of left and right FRP bumper beam extensions 18, 18 are fixed to the front ends of the front side frame front portions 14, 14, and an FRP bumper beam 19 extending in the vehicle width direction at the front ends of the bumper beam extensions 18, 18. Is fixed. The front surface of the bumper beam 19 is covered with a bumper face 20. An FRP shroud 21 formed in a rectangular frame shape when viewed from the front is disposed at a position surrounded by the front bulkhead 17, the bumper beam 19, and the pair of left and right bumper beam extensions 18, 18. Further, cooling system components (not shown) such as an engine cooling radiator, an air conditioning condenser, and a battery cooling radiator are overlapped and supported in the front-rear direction.

  Next, the structure of the bumper beam 19 is demonstrated based on FIG. 3 and FIG.

  The bumper beam 19 made of FRP includes a rear body portion 31 and front initial load absorbing portions 32. The main body 31 includes a pair of U-shaped cross-sections 33, 33 that have an upper wall 33a, a lower wall 33b, and a bottom wall 33c and that open toward the front. The upper flange 33d and the lower flange 33e of the upper U-shaped section 33 are overlapped in the front-rear direction and welded together to form a substantially W-shaped section. Inside the U-shaped cross-section 33, a plurality of vertical ribs 33f that extend in the vertical direction and connect the upper wall 33a, the lower wall 33b, and the bottom wall 33c are separated by a predetermined distance in the longitudinal direction of the bumper beam 19. Formed. The upper flange 33d of the upper U-shaped cross section 33 and the lower flange 33e of the lower U-shaped cross section 33 are formed with a plurality of pins 33g projecting forward. A plurality of fastening collars 34 are inserted into the bottom wall 33c of the U-shaped cross section 33.

  The initial load absorbing portions 32 are divided into three in the longitudinal direction of the bumper beam 19, and each has substantially the same structure. Each initial load absorbing portion 32 includes a flat connecting wall 32a, and a plurality of vertical ribs 32b and a plurality of horizontal ribs 32c formed on the front surface of the connecting wall 32a. The vertical ribs 32b extending in the vertical direction and the horizontal ribs 32c extending in the left-right direction intersect with each other in a lattice shape. Pin holes 32d, into which the pins 33g of the main body 31 can be fitted, are formed on the upper and lower edges of the connecting wall 32a. The initial load absorbing portion 32 is coupled to the main body portion 31 by fitting the pins 33g of the main body portion 31 into the pin holes 32d of the initial load absorbing portion 32 and melting the pins 33g with a vibration tool.

  Next, the structure of the bumper beam extension 18 will be described with reference to FIGS.

  The bumper beam extension 18 is configured by connecting the upper member 51 and the lower member 52, and the planar shape thereof is a trapezoidal shape or a triangular shape. That is, the inner end in the vehicle width direction of the bumper beam extension 18 extends linearly in the front-rear direction, the inner end (rear end) in the front-rear direction extends linearly in the vehicle width direction, and the outer end (front end) in the front-rear direction extends in the vehicle width direction. The outer side is inclined to the inner side in the front-rear direction (rear side). Therefore, the front-rear width of the bumper beam extension 18 is the largest at the inner end in the vehicle width direction and the smallest at the outer end in the vehicle width direction. The front end of the bumper beam extension 18 is inclined rearward from the inner side in the vehicle width direction toward the outer side in the vehicle width direction, so that the corners of the vehicle body are rounded to avoid contact with an obstacle in a narrow place. it can. Since the upper member 51 and the lower member 52 of the bumper beam extension 18 have a substantially plane symmetrical structure, the structure will be described below with the upper member 51 as a representative.

  The upper member 51 includes an inner layer portion made of continuous fiber reinforced resin, and an outer layer portion made of discontinuous fiber reinforced resin that covers the entire outer surface and a part of the inner surface of the inner layer portion. The inner layer portion is displayed in a dark color in FIGS. 8 and 9, and the outer layer portion is displayed in a light color in FIGS. 8 and 9.

  The upper member 51 in which the continuous fiber reinforced resin and the discontinuous fiber reinforced resin are laminated is manufactured as follows. As shown in FIG. 10A, a mold 55 for press-molding the upper member 51 of the bumper beam extension 18 includes a female die 56 having a concave cavity 56a for molding the outer surface of the upper member 51, and the upper member 51. Are formed in the cavity 56a and the core 57a, and grooves 56b, 57b,... Are formed in the cavity 56a and the core 57a. With the mold 55 opened, a first prepreg 58 of discontinuous fiber reinforced resin, a second prepreg 59 of continuous fiber reinforced resin, and a third discontinuous fiber reinforced resin are formed on the cavity 56a of the female mold 56. The prepreg 60 is disposed in a preheated state.

  The second prepreg 59 is composed of two layers of carbon fiber continuous fibers UD (sheets of continuous fibers aligned in one direction) laminated in two directions at 0 ° and 90 °, and the first and third prepregs. 58 and 60 are made of carbon fiber discontinuous fiber mats as reinforcements, and are impregnated with a thermoplastic resin (nylon 6, nylon 66, polypropylene, etc.). A plurality of preheated prepregs are inserted into a mold in a laminated state and subjected to pressure molding, and then cooled to obtain a fiber reinforced resin product.

  The length of the discontinuous fibers of the first prepreg 58 and the third prepreg 60 of the discontinuous fiber reinforced resin is 0.9 mm to 100 mm, but is preferably about 50 mm from the viewpoint of impact absorption performance. In order to achieve both cost and impact absorption performance, the fiber of each prepreg 58, 59, 60 is preferably glass fiber, and the thermoplastic resin is preferably nylon 6 or nylon 66.

  When the male mold 57 is lowered with respect to the female mold 56, the second prepreg 59 is pressed by the cavity 56a of the female mold 56 and the core 57a of the male mold 57, and the upper member 51 is molded. At this time, since the first and third prepregs 58 and 60 using the discontinuous fiber as a reinforcing material can be easily deformed, the first prepreg 58 sandwiched between the second prepreg 59 and the cavity 56a of the female die 56 is It flows into the grooves 56b of the cavity 56a, and the ribs and the like on the outer surface of the upper member 51 are simultaneously formed and laminated in a thin film shape along the entire outer surface of the upper member 51. Similarly, the third prepreg 60 sandwiched between the second prepreg 59 and the core 57a of the male mold 57 flows into the grooves 57b of the core 57a, and simultaneously molds ribs and the like on the inner surface of the upper member 51, The upper member 51 is laminated in a thin film shape along a part of the inner surface of the upper member 51 (part forming a closed cross section). And the upper member 51 is completed by cut | disconnecting the excess part of the outer periphery of the product taken out from the metal mold | die 55. FIG.

  As shown in an enlarged circle in FIG. 8, among the continuous fibers 61 of the second prepreg 59, one continuous fiber 61 is oriented in the front-rear direction, and the other continuous fiber 62 is the vehicle width. Oriented in the direction or up and down direction. Further, the discontinuous fibers 63 of the first and third prepregs 58 and 60 are entangled randomly.

  A continuous fiber reinforced resin having a long fiber UD as a reinforcing material has a relatively high strength. However, since there is a limit to the amount of deformation of the UD, the moldability is low, and it is difficult to mold thin and high ribs. It is. On the other hand, discontinuous fiber reinforced resin having short fibers that are randomly intertwined as a reinforcing material has a relatively low strength, but because the fibers are easily deformed, the moldability is high, and thin and high ribs are formed. Easy to do. Therefore, by laminating the discontinuous fiber reinforced resin on the continuous fiber reinforced resin and molding the upper member 51, the strength and formability of the upper member 51 can be compatible.

  The upper member 51 formed as described above includes a main body 51a extending in the vehicle width direction while being bent into a corrugated plate shape in a substantially trapezoidal or substantially triangular shape in plan view, and upward from the front edge of the main body 51a. The front fastening flange 51b to be bent, the rear fastening flange 51c to be bent upward from the rear edge of the main body 51a, and the four joints 51d to 51g extending in the vehicle width direction on the inner surface of the main body 51a in the front-rear direction. With. First reinforcing ribs 51h... Intersecting in three directions at intervals of 60 ° are formed on the inner surface between the two joining portions 51d and 51e with at least two discontinuous fiber reinforced resins in the front-rear direction (the first reinforcing ribs in FIG. 8). 52h, the second reinforcing ribs 51i... For connecting the front fastening flange 51b and the rear fastening flange 51c are also formed of discontinuous fiber reinforced resin on the outer surface of the main body 51a.

  The two second reinforcing ribs 51i, 51i on the outer surface of the main shock absorbing portion 18a extend in parallel with the axis of the main shock absorbing portion 18a, and are formed on the outer surfaces of the first sub shock absorbing portion 18b and the second sub shock absorbing portion 18c. The two second reinforcing ribs 51i, 51i extend in parallel to the axes of the first sub impact absorbing portion 18b and the second sub impact absorbing portion 18c (see FIG. 5).

  Then, three nuts 64 are inserted into the front fastening flange 51b of the discontinuous fiber reinforced resin that is bent upward at the front end of the upper member 51, and the discontinuous fiber reinforced resin is bent at the rear end of the upper member 51 upward. Three fastening holes 51j are formed in the rear fastening flange 51c (see FIG. 8).

  Since the lower member 52 has the same shape that is substantially plane-symmetric with the upper member 51 described above, the same subscript as the subscript of each part of the upper member 51 is added to the reference numeral 52 of the lower member 52 so as to overlap. Description is omitted. The only difference between the upper member 51 and the lower member 52 is that the lower member 52 includes a plurality of pins 52k that protrude upward from the four joint portions 52d to 52g, whereas the upper member 51 includes the pins 52k. It is a point provided with a plurality of pin holes 51m which can be fitted (see FIG. 8).

  4, 5, and 7, the main closed cross-sectional portion 22 of the bumper beam extension 18 moves up and down the main impact absorbing portions 18 a and 18 a that form a rectangular cross-sectional shape of the upper member 51 and the lower member 52. The first sub-closed cross-section portion 23 and the second sub-closed cross-section portion 24 of the bumper beam extension 18 are the first sub-close cross-section portion 24 and the first sub-close cross-section portion 24. The shock absorbers 18b and 18b and the second sub shock absorbers 18c and 18c are vertically coupled. The axis of the main shock absorbing portion 18a, that is, the axis of the main closed cross section 22 is aligned in the front-rear direction, but the axis of the first sub shock absorbing portion 18b and the second sub shock absorbing portion 18c, that is, the first sub closed cross section. The axis lines of the portion 23 and the second sub-closed cross-section portion 24 are inclined so that the front side faces the outside in the vehicle width direction (see FIG. 5).

  9 and 10B, the main closed cross-section 22 of the bumper beam extension 18 includes a first prepreg 58 of discontinuous fiber reinforced resin, a second prepreg 59 of continuous fiber reinforced resin, and discontinuous fibers. The third prepreg 60 made of reinforced resin is laminated to form a three-layer structure. A discontinuous fiber reinforced resin first prepreg 58 and a continuous fiber reinforced resin second prepreg 59 and a laminated two-layer structure are not included.

  Accordingly, the outer surfaces of the upper member 51 and the lower member 52 are all covered with the first prepreg 58 made of discontinuous fiber reinforced resin, and the inner surfaces of the upper member 51 and the lower member 52 are partially made of the continuous fiber reinforced resin. The second prepreg 59 is exposed, and the other part is covered with the third prepreg 60 of discontinuous fiber reinforced resin.

  The upper member 51 and the lower member 52 having the above-described shapes are configured such that the pins 52k of the lower member 52 are fitted into the pin holes 51m of the upper member 51 so that the joint portions 51d to 51g and 52d to 52g are brought into contact with each other. In this state, the tips of the pins 52k... Are melted together by a vibrating tool from the upper member 51 side (see FIG. 7). In this state, the rear fastening flanges 51c and 52c of the upper member 51 and the lower member 52 are linearly aligned in the vertical direction, but the front fastening flanges 51b and 52b of the upper member 51 and the lower member 52 are tilted forward. (See FIG. 6).

  The bumper beam extension 18 in which the upper member 51 and the lower member 52 are coupled to each other includes a rectangular cylindrical main closed cross-sectional portion 22 that is located on the inner side in the vehicle width direction and extends in the front-rear direction, and an elliptic cylindrical shape adjacent to the outer side in the vehicle width direction The first sub closed section 23 and an elliptic cylindrical second sub closed section 24 adjacent to the outside in the vehicle width direction are provided (see FIG. 7). The cross-sectional areas of the first and second sub closed cross-section portions 23 and 24 are equal to each other and smaller than the cross-sectional area of the main closed cross-section portion 22. In addition, since the width in the front-rear direction of the trapezoidal or triangular bumper beam extension 18 is gradually narrowed from the inner side to the outer side in the vehicle width direction in plan view, the length in the front-rear direction is the longest in the main closed cross section 22. Next, the first sub closed cross-section portion 23 is long, and the second sub closed cross-section portion 24 is the shortest (see FIG. 5).

  Next, the mounting structure of the bumper beam extension 18 to the front bulkhead 17 and the bumper beam 19 will be described with reference to FIGS.

  A mounting plate 81 made of a metal plate is welded to the front end of the front side frame front portion 14, and a bracing member 82 made of a metal plate is attached to the vehicle width direction outer end of the mounting plate 81 and the vehicle width direction outer surface of the front side frame front portion 14. Are welded. Then, six bolts 83 that pass through the rear fastening flanges 51c and 52c of the bumper beam extension 18 from front to rear are screwed into weld nuts 84 provided on the rear surface of the mounting plate 81, so that the bumper beam extension 18 and the front are fixed. The bulkhead 17 is fastened together with the mounting plate 81.

  Further, bolts 85 penetrating through the fastening collars 34 inserted into the main body 31 of the bumper beam 19 from the front to the rear are screwed into nuts 64 inserted into the front fastening flanges 51 b and 52 b of the bumper beam extension 18. The bumper beam 19 is fastened to the front ends of the bumper beam extensions 18 and 18.

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

  The collision load input from the bumper beam 19 to the bumper beam extension 18 due to the frontal collision of the vehicle is transmitted to the front side frame front part 14 via the mounting plate 81 and the bracing member 82, so that the collision load is transmitted to the front side frame front part. 14 can be efficiently transmitted.

  At this time, the bumper beam extension 18 combines a pair of main impact absorbing portions 18a and a main closed section 22 configured as a closed section, and a pair of first and second sub impact absorbing portions 18b and 18c. Since the first and second sub closed cross-section portions 23 and 24 having a closed cross section are provided, the main impact absorbing portion 18a and the first and second sub impact absorbing portions 18b and 18c are closed to suppress opening. Thus, the shock absorbing performance can be enhanced.

  When the vehicle collides with the front and the collision load in the front-rear direction indicated by the arrow A in FIG. 5 is input, the main impact absorbing portion 18a (main closed cross-section portion 22) having the axis in the front-rear direction is crushed in the axial direction and effective. Can exhibit excellent shock absorption performance. Further, when the vehicle collides obliquely and an oblique collision load indicated by an arrow B in FIG. 5 is input, the first sub-impact absorber 18b and the second sub-impact absorber 18c (first sub-close) having an oblique axis. The cross-sectional portion 23 and the second sub-closed cross-sectional portion 24) can be crushed in the axial direction to exhibit effective shock absorbing performance.

  As described above, by changing the axial direction of the main impact absorbing portion 18a and the axial directions of the first sub impact absorbing portion 18b and the second sub impact absorbing portion 18c, the collision load of the frontal collision and the diagonal It is possible to effectively absorb both the collision loads of the collision. In particular, the collision load of the frontal collision is transmitted from the main shock absorbing portion 18a of the bumper beam extension 18 to the front end of the front side frame front portion 14 linearly connected to the rear thereof, and the collision load of the oblique collision is transmitted to the bumper beam extension 18. Since it is transmitted from the first auxiliary shock absorbing portion 18b and the second auxiliary shock absorbing portion 18c to the side surface on the outer side in the vehicle width direction of the front side frame front portion 14 via the bracing member 82, the collision load in any direction Even so, the bumper beam extension 18 can be reliably crushed without tilting.

  As shown in FIG. 11, when a collision load is input to the main impact absorbing portion 18a, the continuous fiber reinforced resin layer supports the tensile load, and the discontinuous fiber reinforced resin layers on both the inner and outer surfaces support the compressive load. The continuous fiber reinforced resin layer suppresses delamination of the continuous fiber reinforced resin layer to enhance the impact absorbing performance, and when the collision load is input to the first and second sub impact absorbing portions 18b and 18c, the continuous fiber reinforced resin layer has a tensile load. Since the discontinuous fiber reinforced resin layer on the outer surface supports the compressive load while supporting the above, delamination of the continuous fiber reinforced resin layer can be suppressed and the shock absorbing performance can be enhanced.

  As shown in FIG. 12, the second reinforcing ribs 51i, 52i,..., 52i, which are made of discontinuous fibers hardened with a thermoplastic resin are formed on the outer surfaces of the main impact absorbing portion 18a and the first and second auxiliary impact absorbing portions 18b, 18c. Are formed in the front-rear direction, so that the second reinforcing ribs 51i... 52i can support the compressive load and thereby more reliably suppress delamination of the continuous fiber reinforced resin layer. The first reinforcing ribs 51h... 52h... In which discontinuous fibers are hardened with a thermoplastic resin are formed on the inner surface of 18a in a direction inclined with respect to the front-rear direction. Even if it exists, the delamination of a continuous fiber reinforced resin layer can be suppressed.

  As shown in FIG. 13, the bumper beam extension 18 includes front fastening flanges 51b and 52b which are bent in a direction crossing the input direction of the collision load and the discontinuous fibers are hardened with a thermoplastic resin. Since the bumper beam 19 is connected to the fastening flanges 51 b and 52 b, when a collision load is input from the bumper beam 19 to the bumper beam extension 18, the front fastening flanges 51 b and 52 b having a large pressure receiving area are triggered (trigger to cause destruction). ) And the bumper beam extension 18 is sequentially crushed in the front-rear direction, so that the shock absorbing performance can be enhanced.

  The continuous fibers of the continuous fiber reinforced resin layer of the main impact absorbing portion 18a are oriented in the front-rear direction, which is the input direction of the collision load, and in the vehicle width direction and the up-down direction perpendicular thereto, and have a square cross section. 18a is provided with a ridge line that forms a corner along the input direction (front-rear direction) of the collision load (see FIGS. 7 and 8), and is deformed so that the ridge line that forms the corner spreads radially outward by the collision load. In some cases, the continuous fibers oriented in the vehicle width direction and the vertical direction can be stretched to increase the amount of shock absorption.

  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 bumper beam extension and bumper beam of the present invention are not limited to those on the front side of an automobile, and may be those on the rear side.

  Further, the vehicle body frame of the present invention is not limited to the front side frame front portion 14 of the embodiment, and may be a frame disposed in the front-rear direction at the vehicle body front portion or the vehicle body rear portion.

  The FRP of the present invention is not limited to the CFRP (carbon fiber fiber reinforced resin) of the embodiment, and may be another type of FRP such as a glass fiber fiber reinforced resin or an aramid fiber fiber reinforced resin.

  The number of sub-impact absorbers 18b and 18c provided in each bumper beam extension 18 is not limited to two in the embodiment, and may be one or three or more.

14 Front side frame front (body frame)
18 Bumper beam extension 18a Main shock absorber 18b First sub shock absorber (sub shock absorber)
18c 2nd sub shock absorption part (sub shock absorption part)
22 Main closed cross section 23 First sub closed cross section (sub closed cross section)
24 2nd sub closed section (sub closed section)
51 Upper member 51b Front fastening flange (flange)
51i Second reinforcing rib (rib)
52 Lower member 52b Front fastening flange (flange)
52i Second reinforcing rib (rib)
81 Mounting plate 82 Bracing member

Claims (7)

A vehicle body structure in which an FRP bumper beam extension (18) is disposed between a vehicle body frame (14) disposed in the front-rear direction and a bumper beam (19) disposed in the vehicle width direction,
The bumper beam extension (18) is integrally provided with a main impact absorbing portion (18a) on the inner side in the vehicle width direction and an auxiliary impact absorbing portion (18b, 18c) on the outer side in the vehicle width direction, and the main impact absorbing portion (18a). Is disposed along the front-rear direction, and the sub-impact absorbers (18b, 18c) are disposed such that the outer side in the front-rear direction is inclined outward in the vehicle width direction.   The vehicle body structure for an automobile according to claim 1, wherein an outer end in the front-rear direction of the bumper beam extension (18) is inclined inward in the front-rear direction from the inner side in the vehicle width direction toward the outer side in the vehicle width direction.   The inner end in the front-rear direction extending in the vehicle width direction of the bumper beam extension (18) is attached to the outer end in the front-rear direction of the vehicle body frame (14) via a mounting plate (81), and the main impact absorbing portion (18a) is The vehicle body frame (14) is linearly connected to the front and rear outer ends, and the sub-impact absorbers (18b, 18c) are connected to the side surface of the vehicle body frame (14) via bracing members (82). The vehicle body structure according to claim 1, wherein the vehicle body structure is a vehicle.   The bumper beam extension (18) is configured by joining an upper member (51) and a lower member (52), and the upper member (51) and the lower member (52) are continuous fibers oriented in the front-rear direction. 4. The vehicle according to claim 1, further comprising: an inner layer in which continuous fibers oriented in a vehicle width direction or in a vertical direction are hardened with a resin; and an outer layer in which discontinuous fibers are hardened with a resin. The vehicle body structure described in the paragraph.   5. The vehicle according to claim 4, wherein the outer layer includes ribs (51 i, 52 i) extending along the axes of the main impact absorbing portion (18 a) and the secondary impact absorbing portion (18 b, 18 c). Body structure.   The said outer layer is provided with the flange (51b, 52b) bent in the direction which cross | intersects the input direction of the collision load of the said bumper beam extension (18), The Claim 4 or Claim 5 characterized by the above-mentioned. Auto body structure.   The bumper beam extension (18) includes a main closed cross-section portion (22) configured to have a closed cross-section by connecting a pair of main impact absorption portions (18a), and a pair of sub-impact absorption portions (18b, 18c). The vehicle body structure according to any one of claims 1 to 6, further comprising sub-closed cross-section portions (23, 24) that are combined to form a closed cross-section.

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