JP5979486B2 - Bumper beam for automobile - Google Patents

Description

  The present invention relates to a bumper beam for an automobile made of FRP having at least two U-shaped cross-sections that are overlapped in the vertical direction.

  Covering a part of the front edge and a part of the rear edge of the plurality of horizontal plates overlaid at a predetermined interval in the vertical direction with the front plate and the rear plate, respectively, and extending the plurality of horizontal plates in the vertical direction A bumper beam made of FRP connected in a lattice pattern with a vertical plate is known from Japanese Patent Application Laid-Open No. 2004-151867.

Japanese Patent No. 4850349

  By the way, what was described in the above-mentioned patent document 1 is that the front plate and the rear plate of the bumper beam are arranged shifted in the vehicle width direction, and the rear plate is not provided behind the front plate. Because the front plate is not provided in front of the bumper beam, the bumper beam has an open cross section that opens forward or backward, and the bumper beam is deformed so that it opens when the collision load is input. Cannot be transmitted efficiently.

  The present invention has been made in view of the above-described circumstances, and an object thereof is to provide an FRP bumper beam that is small and light and has high strength.

In order to achieve the above object, according to the first aspect of the present invention, the FRP bumper beam that connects between the left and right bumper beam extensions of the FRP that are crushed by the input of the collision load is provided in the vehicle width direction. comprise a body portion having at least one substantially W-shaped cross-section at least two U-shaped cross section superimposed vertically opened to the input side of the collision load extends, said U-shaped Among the upper wall, the lower wall, and the bottom wall of the cross section, at least the inner surfaces of the upper wall and the lower wall are connected by a plurality of vertical ribs extending in the vertical direction, and the bumper beam extension is formed by the upper member and the lower member. be configured as a combination, comprises a plurality of closed-section portion which is juxtaposed to Rutotomoni vehicle width direction extend in the longitudinal direction is formed in a cylindrical shape between these upper member and a lower member, before Bumper beam in the vehicle width direction of the width of the extension is greater than the longitudinal width, the width of the longitudinal direction of automobile bumper beam, characterized in that gradually narrows from the inner side in the vehicle width direction toward the outside is proposed.

  According to the second aspect of the present invention, in addition to the configuration of the first aspect, the front-rear direction inner end portion of the bumper beam extension is fixed to the front-rear direction outer end portion of the front side frame. A bumper beam for automobiles is proposed, which is connected to a mounting plate extending outward, and the mounting plate and the front side frame are connected by a brace member.

  According to the invention described in claim 3, in addition to the configuration of claim 1 or 2, the bumper beam extension includes a reinforcing rib extending in the front-rear direction. Is done.

  According to the invention described in claim 4, in addition to the configuration of any one of claims 1 to 3, the vertical distance between the upper wall and the lower wall of the U-shaped cross section is An automobile bumper beam is proposed that expands toward the input side of the collision load.

  According to the invention described in claim 5, in addition to the configuration of any one of claims 1 to 4, an outer layer of continuous fiber FRP and an inner layer of discontinuous fiber FRP are laminated to form the U A bumper beam for automobiles is proposed, characterized in that it has a letter-shaped cross section and the longitudinal ribs are formed integrally with the inner layer of the discontinuous fiber FRP.

  According to the invention described in claim 6, in addition to the configuration of claim 5, the continuous fiber FRP includes a first continuous fiber and a second continuous fiber arranged in directions intersecting each other, and A bumper beam for automobiles is proposed in which the first continuous fibers are arranged in the vehicle width direction.

  According to the invention described in claim 7, in addition to the structure of claim 6, an automobile bumper beam is proposed in which the second continuous fibers are arranged in the front-rear direction or the vertical direction.

  According to the invention described in claim 8, in addition to the configuration of any one of claims 1 to 7, the inner surfaces of the upper wall, the lower wall, and the bottom wall of the U-shaped cross-sectional portion are A bumper beam for automobiles characterized by being connected by a plurality of vertical ribs is proposed.

  According to the invention described in claim 9, in addition to the configuration of any one of claims 1 to 8, the two U-shaped cross-sectional portions are overlapped with the upper flange and the lower flange. An automobile bumper beam is proposed in which the substantially W-shaped main body is configured by joining together.

  According to the invention described in claim 10, in addition to the configuration of any one of claims 1 to 9, a U-shaped fastening collar for fastening the bumper beam to the bumper beam extension is provided. A bumper beam for automobiles is proposed, which is inserted into the bottom wall of the cross section.

  According to the invention described in claim 11, in addition to the structure of claim 10, the bumper beam extension includes upper and lower front fastening flanges for supporting the bumper beam, and the upper and lower front fastening flanges are An automobile bumper beam is proposed that expands in the vertical direction toward the bumper beam.

  According to a twelfth aspect of the invention, in addition to the configuration of the tenth or eleventh aspect, the bumper beam extension includes a plurality of the closed cross-section portions, and the plurality of closed cross-section portions are in the vehicle width direction. A bumper beam for automobiles characterized by being juxtaposed with each other is proposed.

  According to the invention described in claim 13, in addition to the structure of any one of claims 1 to 12, the main body portion closes the openings of the two U-shaped cross-section portions. And an initial load absorbing member comprising a connecting wall coupled to each other and a plurality of ribs formed on the input side of a collision load of the connecting wall and extending in the vertical direction and the vehicle width direction. A bumper beam is proposed.

  According to a fourteenth aspect of the present invention, in addition to the configuration of the thirteenth aspect, the upper and lower edges of the main body and the upper and lower edges of the initial load absorbing member are combined. Is proposed.

  The front side frame front portion 14 of the embodiment corresponds to the front side frame of the present invention, and the first closed cross section 18a, the second closed cross section 18b, and the second closed cross section 18c of the embodiment are the present invention. The vertical rib 32b and the horizontal rib 32c of the embodiment correspond to the rib of the present invention, and the second reinforcing ribs 51i and 52i of the embodiment correspond to the reinforcing rib of the present invention.

According to the configuration of the first aspect, at least two bumper beams made of FRP that connect between the left and right bumper beam extensions that are crushed by the input of the collision load extend in the vehicle width direction and open to the input side of the collision load. And a main body having at least one substantially W-shaped cross section in which the U-shaped cross sections are superposed in the vertical direction. Of the upper, lower and bottom walls of the U-shaped cross section, at least the inner surfaces of the upper and lower walls are connected by a plurality of vertical ribs extending in the vertical direction. The vertical ribs prevent the upper and lower walls of the U-shaped cross-section from opening when they are input to the bumper beam, causing the bumper beam to bend and deform in the direction in which the collision load acts, generating a reaction force The collision load can be efficiently and intensively transmitted from the U-shaped cross section to the pair of left and right bumper beam extensions, and the bumper beam extensions can be sequentially crushed from the tip side to absorb energy. Moreover, the amount of energy absorption can be increased while minimizing the size of the bumper beam in the input direction of the collision load by superimposing at least two U-shaped cross-sections in the vertical direction. Furthermore, the vertical dimension of the bumper beam can be increased to prevent the collision with the collision object. The bumper beam extension made of FRP is configured as a combined body of the upper member and the lower member. The upper member and the lower member are formed into a cylindrical shape, extend in the front-rear direction, and juxtaposed in the vehicle width direction. of has a closed cross-section portion, the bumper beam in the vehicle width direction of the width of the extension is greater than the longitudinal width, the width of the longitudinal direction is gradually narrowed toward the outside from the inside in the vehicle width direction, the bumper beam extension The size in the front-rear direction can be reduced to improve the mountability to the vehicle body, and the sufficient width of the bumper beam extension in the vehicle width direction can be secured to ensure the amount of energy absorbed during a narrow offset collision.

  According to the second aspect of the present invention, the front and rear inner ends of the bumper beam extension are connected to the mounting plate that is fixed to the front and rear outer ends of the front side frame and extends outward in the vehicle width direction. Since the front side frame is connected to the front side frame by a brace member, even if a collision load is input to the outer end of the bumper beam extension in the vehicle width direction due to a narrow offset collision, the front side frame is passed through the mounting plate and the brace member. Can be transmitted efficiently.

  According to the third aspect of the present invention, since the bumper beam extension includes the reinforcing rib extending in the front-rear direction, it is possible to increase the strength of the bumper beam extension against the collision load and increase the amount of energy absorption.

  According to the fourth aspect of the present invention, the vertical distance between the upper wall and the lower wall of the U-shaped cross section increases toward the collision load input side. By expanding the directional dimension, it is possible to receive impact loads of various sizes and input from different heights.

  According to the configuration of claim 5, the outer layer of the continuous fiber FRP and the inner layer of the discontinuous fiber FRP are laminated to form the U-shaped cross section, and the vertical rib is formed integrally with the inner layer of the discontinuous fiber FRP. As a result, the strength of the U-shaped cross-section is ensured by the continuous fiber FRP having high strength, and the orientation of the continuous fiber is disturbed or the continuous fiber is broken by the discontinuous fiber FRP having high formability. And can be easily molded. As a result, the opening of the U-shaped cross section can be more reliably suppressed and the bending strength of the bumper beam can be increased.

  According to the sixth aspect of the present invention, the continuous fiber FRP includes the first continuous fiber and the second continuous fiber arranged in the direction intersecting each other, and the first continuous fiber is arranged in the vehicle width direction. When a collision load is input to the U-shaped cross section of the beam, the strength of the U-shaped cross section against bending deformation in the front-rear direction can be increased by the first continuous fiber.

  According to the seventh aspect of the present invention, since the second continuous fibers are arranged in the front-rear direction or the up-down direction, when a collision load is input to the U-shaped cross section of the bumper beam, the U-shaped cross section opens. This can be suppressed by the second continuous fiber.

  Further, according to the configuration of claim 8, since the inner surfaces of the upper wall, the lower wall and the bottom wall of the U-shaped cross section are connected by a plurality of vertical ribs, the bumper beam has a closed cross section or a continuous fiber inclined by 45 ° It is possible to increase the strength against torsional deformation of the U-shaped cross-section without adding cost and weight-intensive reinforcement such as the addition of.

  Further, according to the configuration of claim 9, since the two U-shaped cross sections are joined by overlapping the upper flange and the lower flange, the substantially W-shaped main body is configured. Not only can the mold be reduced in size compared with the case of being integrally molded, but also the strength can be ensured by minimizing the disturbance in the orientation direction of the first and second continuous fibers of the U-shaped cross section. it can.

  According to the structure of claim 10, since the fastening collar for fastening the bumper beam to the bumper beam extension is inserted into the bottom wall of the U-shaped cross section, the collision load can be supported at the center of the U-shaped cross section. In addition, the bumper beam can be easily and firmly fixed to the bumper beam extension from the opening side.

  According to the structure of claim 11, the bumper beam extension includes upper and lower front fastening flanges that support the bumper beam, and the upper and lower front fastening flanges expand in the vertical direction toward the bumper beam. Can efficiently transmit the collision load input from the front to the center axis in the front-rear direction of the bumper beam extension, and the bumper beam extension can be reliably crushed to enhance the energy absorption effect.

  According to the structure of the twelfth aspect, the bumper beam extension has a plurality of closed cross sections, and the plurality of closed cross sections are juxtaposed in the vehicle width direction, so that the collision load can be efficiently absorbed at the time of the narrow offset collision. Not only that, it is possible to reduce the size of the bumper beam extension in the front-rear direction while securing the amount of energy absorption, and to improve the mountability to the vehicle body.

  According to the structure of claim 13, the upper and lower surfaces are formed on the connecting wall coupled to the main body so as to close the openings of the two U-shaped cross-sections, and the input side of the collision load of the connecting wall. Since the initial load absorbing member consisting of a large number of ribs extending in the direction and the vehicle width direction is provided, the initial collision load can be efficiently absorbed by the crushing of the ribs, and the space between the bumper face and the bumper beam can be absorbed. It can be used to absorb the initial load.

  According to the structure of the fourteenth aspect, since the upper and lower edges of the main body and the upper and lower edges of the initial load absorbing member are joined together, it is possible to prevent the U-shaped cross-section of the main body from opening due to a collision load. The bending strength of the beam can be further increased.

The perspective view of the vehicle body front part of a motor vehicle. FIG. The perspective view of a bumper beam. FIG. 4 is a sectional view taken along line 4-4 of FIG. FIG. 5 is a sectional view taken along line 5-5 of FIG. Explanatory drawing of the manufacturing method of a U-shaped cross section. FIG. 7 is a sectional view taken along line 7-7 in FIG. The exploded perspective view of a bumper beam extension. Action | operation explanatory drawing at the time of the input of the collision load to a bumper beam.

  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, and the input direction of the collision load at the time of frontal collision is the front.

  As shown in FIGS. 1 and 2, the hybrid vehicle of the embodiment includes a cabin 11 integrally formed in a bathtub shape with CFRP (carbon fiber reinforced resin), and aluminum is provided on the front surface of a dash panel 12 standing from its front end. A pair of left and right suspension support members 13, 13 die-cast with an alloy are fixed. 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 CFRP side members 16, 16 are connected to front ends of a pair of left and right CFRP upper members 15, 15 extending forward from the upper left and right sides of the dash panel 12.

A front bulkhead 17 made of fiber reinforced resin (FRP), which is formed in a rectangular frame shape when viewed from the front, is fixed to the front ends of the front side frame front portions 14, 14. The front ends of 16 and 16 are connected. Fiber reinforced pair of left and right left and right front surface of the front bulkhead 17 resin (FRP) made of the bumper beam extension 18 and 18 are fixed, the fiber-reinforced resin extending in the vehicle width direction at the front end of the bumper beam extension 18 and 18 ( The bumper beam 19 made of FRP) is fixed. The front surface of the bumper beam 19 is covered with a bumper face 20. A fiber reinforced resin (FRP) shroud 21 formed in a rectangular frame shape in front view 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. In the shroud 21, three cooling system parts including an engine cooling radiator 22, an air conditioning condenser 23, and a battery cooling radiator 24 are overlapped and supported in the front-rear direction.

  Next, the structure of the bumper beam 19 will be described with reference to FIGS.

  The bumper beam 19 made of fiber reinforced resin includes a rear main 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 arranged in the longitudinal direction of the bumper beam 19 (left-right direction or vehicle width). (Direction) and spaced apart by a predetermined distance. 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 18, 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 vibrating tool ( (See FIG. 5).

  As shown in FIG. 6B, the U-shaped cross section 33 is formed by laminating continuous fibers on the outer surface and discontinuous fibers on the inner surface. The U-shaped cross section 33 is manufactured as follows. As shown in FIG. 6A, a mold 55 for press-molding the U-shaped cross-section 33 includes a female mold 56 having a concave cavity 56a for molding the outer surface of the U-shaped cross-section 33, and a U-shape. Is formed with a male mold 57 having a convex core 57a for molding the inner surface of the cross-section 33, and grooves 57b for molding vertical ribs 33f are formed in the core 57a. In a state where the mold 55 is opened, a discontinuous fiber prepreg 58 and a continuous fiber prepreg 59 are disposed on the cavity 56a of the female die 56 in a preheated state.

  The prepreg can use continuous fibers or discontinuous fibers such as glass fibers (glass fibers), carbon fibers, aramid fibers, etc., and these continuous fibers are woven fabric or UD (a sheet in which continuous fibers are aligned in one direction), Alternatively, a discontinuous fiber mat is used as a reinforcing material, and it is impregnated with a semi-cured thermosetting resin (such as epoxy resin or polyester resin) or a thermoplastic resin (such as nylon 6 or polypropylene). Flexibility to adapt to the shape. In the case of a thermosetting resin, when a plurality of prepregs are inserted into a mold in a laminated state and heated to, for example, about 130 ° C. while applying pressure, the thermosetting resin is cured and a fiber reinforced resin product is obtained. . In the case of a thermoplastic resin, a plurality of preheated prepregs are inserted into a mold in a laminated state, subjected to pressure molding, and then cooled to obtain a fiber reinforced resin product.

  When the male mold 57 is lowered with respect to the female mold 56, the discontinuous fiber prepreg 58 and the continuous fiber prepreg 59 are pressed by the cavity 56a of the female mold 56 and the core 57a of the male mold 57, and the U-shaped cross-section 33 is formed. Molded. At this time, since the discontinuous fiber prepreg 58 can be easily deformed, it flows into the grooves 57b of the core 57a, and simultaneously forms the vertical ribs 32b of the inner surface of the U-shaped cross-section 33, and the U-shape. A thin film is laminated along the inner surface of the cross-section 33. As shown in FIG. 6 (B), after cutting the excess portion of the outer periphery of the U-shaped cross section 33 taken out from the mold 55, the lower U-shaped cross section as shown in FIG. 6 (C). The upper flange 33d of 33 and the lower flange 33e of the upper U-shaped cross-section 33 are overlapped in the front-rear direction and welded together to complete the main body 31.

  The continuous fiber reinforced resin of the continuous fiber prepreg 59 is orthogonal as shown in an enlarged view in the circle of FIG. 3 (the initial load absorbing member 32 on the left side of the three divisions is omitted and the bumper beam 19 is shown). The first and second continuous fibers 60... 61 61 oriented in two directions are reinforced with a plain weave. Further, the discontinuous fiber reinforced resin of the discontinuous fiber prepreg 58 is reinforced by a random entanglement of the discontinuous fibers 62.

  Long fiber woven fabric and continuous fiber reinforced resin having UD as a reinforcing material have a relatively high strength, but because of the limited amount of deformation of woven fabric and UD, the moldability is low, and thin and high ribs, etc. Is difficult to mold. 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 inside the continuous fiber reinforced resin and forming the U-shaped cross section 33, the strength and formability of the U-shaped cross section 33 can be compatible.

  Next, the structure of the bumper beam extension 18 will be described with reference to FIGS. 4, 7 and 8.

Since the bumper beam extension 18 is formed as a conjugate of the upper member 51 and lower member 52, the upper member 51 and lower member 52 are substantially plane symmetrical structure, hereinafter, the structure upper member 51 as a representative explain.

  The upper member 51 of the bumper beam extension 18 includes a main body 51a extending in the vehicle width direction while being bent into a corrugated plate shape, a front fastening flange 51b bent upward from a front edge of the main body 51a, and a rear edge of the main body 51a. A rear fastening flange 51c that is bent upward, and four joint portions 51d to 51g that extend in the front-rear direction at positions separated from each other in the vehicle width direction on the inner surface of the main body 51a. First reinforcing ribs 51h (which are the same as the first reinforcing ribs 52h in FIG. 8) intersecting in three directions at intervals of 60 ° are formed on the inner surface between the two joint portions 51d and 51e, and are formed on the outer surface of the main body portion 51a. Is formed with six second reinforcing ribs 51i that extend in the front-rear direction and connect the front fastening flange 51b and the rear fastening flange 51c.

  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 pins 52k... Are melted together from the upper member 51 side with a vibrating tool to be coupled together (see FIG. 7). In this state, the rear fastening flanges 51c, 52c of the upper member 51 and the lower member 52 are linearly aligned in the vertical direction, but the front fastening flanges 51b, 52b of the upper member 51 and the lower member 52 are inclined forward. It spreads while being inclined (see FIG. 4). Three nuts 63 are inserted into the front fastening flanges 51b and 52b, and bolts 64 penetrating the fastening collars 34 from the opening side of the U-shaped cross-sections 33 and 33 are inserted into the nuts 63. And the bumper beam 19 is fixed to the bumper beam extension 18.

  A bumper beam extension 18 in which the upper member 51 and the lower member 52 are coupled to each other includes a rectangular tube-shaped first closed cross-sectional portion 18a that is located on the inner side in the vehicle width direction and extends in the front-rear direction, and an elliptic cylinder adjacent to the outer side in the vehicle width direction. A second closed cross-sectional portion 18b having a shape and an elliptic cylindrical third closed cross-sectional portion 18c adjacent to the outside in the vehicle width direction are provided. The cross-sectional areas of the second and third closed cross-section portions 18b and 18c are equal to each other and smaller than the cross-sectional area of the first closed cross-section portion 18a. Further, since the front-rear width of the bumper beam extension 18 is gradually narrowed from the inner side to the outer side in the vehicle width direction, the length in the front-rear direction is the longest in the first closed cross-sectional portion 18a, and then the second closed cross-sectional portion 18b. Is long and the third closed cross section 18c is the shortest (see FIG. 2). The rear end of the first closed cross section 18a is joined to the front ends of the pair of left and right front side frame front portions 14,14.

  As described above, the bumper beam extension 18 includes the second and third closed cross-section portions 18b and 18c having a cross-sectional area smaller than that of the first closed cross-section portion 18a on the outer side in the vehicle width direction of the first closed cross-section portion 18a. In addition, not only can the second and third closed cross-sections 18b and 18c perform shock absorption at the time of a narrow offset frontal collision that collides from the front to the vehicle width direction outside of the pair of left and right front side frame front parts 14 and 14, but also the vehicle width By performing shock absorption with the first to third closed cross-section portions 18a, 18b, and 18c juxtaposed in the direction, the amount of energy absorption can be ensured while shortening the longitudinal dimension of the bumper beam extension 18.

  Further, with the pins 52k formed in the lower member 52 being fitted into the pin holes 51m formed in the upper member 51, the tips of the pins 52k are melted from the upper member 51 side to join the upper member 51 and the lower member 52 together. Thus, not only can the upper member 51 and the lower member 52 be coupled with high accuracy, but also the energy absorption can be ensured by preventing the upper member 51 and the lower member 52 from being separated during a frontal collision.

  In addition, front fastening flanges 51b, 52b and rear fastening flanges 51c, 52c are formed at the front and rear ends of the bumper beam extension 18, respectively, and the second reinforcement extends in the front-rear direction through the front fastening flanges 51b, 52b and the rear fastening flanges 51c, 52c. Since the ribs 51i, 52i, etc. are connected, not only can the bumper beam extension 18 be firmly coupled to the bumper beam 19 and the front side frame front part 14, but also the strength of the bumper beam extension 18 with respect to a collision load can be increased to increase energy absorption. Can be increased.

  Further, 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 made of a metal plate is formed on the outer end in the vehicle width direction of the mounting plate 81 and the outer surface in the vehicle width direction of the front side frame front portion 14. 82 is welded diagonally (see FIG. 2). Then, six bolts 83... Passing through the rear fastening flanges 51 c and 52 c of the bumper beam extension 18, the front bulkhead 17 and the mounting plate 81 from the front to the rear are screwed into weld nuts 84 provided on the rear surface of the mounting plate 81. Thus, the bumper beam extension 18 and the front bulkhead 17 are fastened together with the mounting plate 81 and joined to the front ends of the pair of left and right front side frames 14 and 14 (see FIG. 4).

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

When the automobile collides front, the collision load is from the center in the longitudinal direction of the bumper beam 19 through the bumper beam extensions 18 and 18 at both ends, the front side frame front portions 14 and 14 and the suspension support members 13 and 13 and the dash panel 12 of the cabin 11. In the process, the bumper beam extensions 18 and 18 are mainly crushed to absorb the collision energy. For this purpose, it is desirable to transmit the collision load to the bumper beam extensions 18 and 18 while maintaining the shape of the main body 31 of the bumper beam 19 without opening or crushing.

According to the present embodiment, when the U-shaped cross section 33 is press-molded with the die 55 of FIG.
As shown in FIG. 3, the outer surface of the U-shaped cross-section 33 is reinforced with first and second continuous fibers 60, 61, which are oriented in two orthogonal directions. The orientation direction of the first continuous fibers 60 is the vehicle width direction (that is, the main stress direction of the upper wall 33a, the lower wall 33b, and the bottom wall 33c of the bumper beam 19), and the orientation direction of the second continuous fibers 61 is the vehicle width. The direction perpendicular to the direction (that is, the vertical direction of the bottom wall 33c and the front-back direction of the upper wall 33a and the lower wall 33b). On the other hand, the inner surface of the U-shaped cross-section 33 and the vertical ribs 33f are reinforced with randomly entangled discontinuous fibers 62.

  In this way, the outer surface of the U-shaped cross-section 33 having a simple U-shaped cross section is reinforced with first and second continuous fibers 60, 61, which are plain woven with high strength, and is plain woven in order to have a complicated shape. By reinforcing the longitudinal ribs 33f, which are difficult to reinforce with the continuous fibers, with the discontinuous fibers 62 with a high degree of freedom in molding, both the bending strength of the bumper beam 19 and the formability of the continuous fibers can be achieved. . In addition, the discontinuous fiber prepreg 58 and the continuous fiber prepreg 59 are arranged in the same mold 55 to form the bumper beam 19 in one step, so that they are separately formed and integrated by bonding or welding. Manufacturing costs can be reduced.

  By the way, as shown in FIG. 9A, when a U-shaped cross section 33 having a simple U-shaped cross section without a rib collides with the front surface and bends and deforms in a chain line state, tensile stress is applied to the bottom wall 33c. The compression stress acts on the front portions of the upper wall 33a and the lower wall 33b. Therefore, by arranging the first continuous fibers 60 of the orthogonal first and second continuous fibers 60, 61 in the main stress direction (vehicle width direction), the bumper beam 19 against bending deformation at the time of frontal collision. The bending strength of can be increased.

  Further, when the U-shaped cross-section 33 collides with the front, as shown in FIG. 9B, the upper wall 33a and the lower wall 33b are deformed so as to open, so the direction orthogonal to the main stress direction. Tensile stress and compressive stress also act, but by arranging the second continuous fibers 61 in that direction, it is possible to increase the strength of the U-shaped cross-section 33 against the mouth opening.

  Therefore, when the U-shaped cross-section 33 collides with the front, high strength can be obtained by arranging the first and second continuous fibers 60... 61 in the vehicle width direction and the direction orthogonal thereto. However, as shown in FIG. 9C, when a collision load offset in the vertical direction is input, the U-shaped cross-section 33 is twisted and deformed, and the first and second continuous fibers 60, 61,. It is difficult to ensure rigidity against torsional deformation simply by arranging them in the orthogonal direction and reinforcing them. However, according to the present embodiment, the upper wall 33a, the lower wall 33b, and the bottom 33c of the U-shaped cross section 33 are connected by the vertical ribs 33f, so that a closed cross section or a continuous fiber inclined by 45 ° is added. Thus, the rigidity against torsional deformation can be sufficiently increased without performing costly and heavy reinforcement.

  Moreover, if the discontinuous fibers 62 are injected together with the resin, the nozzle may be clogged. However, by forming the discontinuous fiber prepreg 58 with the mold 55, the discontinuous fibers 62 having a sufficient length can be obtained. It can be used and the strength of the U-shaped cross-section 33 can be increased.

  Further, since the entire region of the opening of the U-shaped cross section 33 that opens toward the front is closed by the connecting wall 32a of the initial load absorbing section 32, the U-shaped cross section 33 is completely closed to increase the strength, The collision load can be efficiently transmitted to the bumper beam extension 18. At that time, since the vertical interval between the upper wall 33a and the lower wall 33b of the U-shaped cross-section 33 increases toward the front, the vertical dimension of the U-shaped cross-section 33 is enlarged to increase the size. It is possible to receive collision loads input from different obstacles and different heights.

  In addition, the pair of upper and lower U-shaped cross-sections 33, 33 are joined by overlapping the upper flange 33d and the lower flange 33e to form the main body 31 having a substantially W-shaped cross section of the bumper beam 19. Compared to the case where the U-shaped cross-sections 33, 33 are integrally molded, the mold 55 can be made smaller, and the first and second continuous fibers 60, 61, 61 of the U-shaped cross-section can be reduced. The strength can be secured by minimizing the disturbance in the orientation direction.

  Since the fastening collars 34 for fastening the bumper beam 19 to the bumper beam extension 18 are inserted into the bottom wall 33c of the U-shaped cross section 33, the bumper beam 19 is attached to the bumper beam extension 18 by fastening from the opening side. Can be easily and firmly fixed. At this time, the bumper beam extension 18 includes front fastening flanges 51b and 52b for supporting the bumper beam 19, and the front fastening flanges 51b and 52b expand in the vertical direction toward the bumper beam 19 (see FIG. 4). ), The collision load input from the bumper beam 19 can be efficiently transmitted to the central axis of the closed cross section of the bumper beam extension 18, and the bumper beam extension 18 can be reliably crushed to enhance the energy absorption effect.

  Further, the initial load absorbing member 32 that closes the opening of the bumper beam 19 includes a connecting wall 32a, and a large number of vertical ribs 32b and a large number of horizontal ribs 32c formed on the outer surface in the front-rear direction of the connecting wall 32a. By collapsing the vertical ribs 32b and the large number of horizontal ribs 32c, the initial collision load at the time of frontal collision can be efficiently absorbed.

  The bumper beam extension 18 includes first to third closed cross sections 18a, 18b, and 18c that are formed in a cylindrical shape and extend in the front-rear direction. The first to third closed cross sections 18a, 18b, and 18c are arranged in the vehicle width direction. Since they are juxtaposed, not only can the collision load be efficiently absorbed at the time of a narrow offset collision, but also the size in the front-rear direction of the bumper beam extension 18 can be reduced while securing the amount of energy absorption, thereby improving the ease of mounting on the vehicle body. Can do.

  Further, the vehicle width direction outer end of the mounting plate 81 fixed to the front end of the front side frame front portion 14 and the vehicle width direction outer surface of the front side frame front portion 14 are connected by a brace member 82, and the bumper beam extension 18 is connected to the mounting plate 81. Since the rear fastening flanges 51c and 52c are coupled, even when a collision load is input to the outer end in the vehicle width direction of the bumper beam extension 18 due to a narrow offset frontal collision, the collision load is transmitted via the mounting plate 81 and the bracing member 82. Thus, it can be efficiently transmitted to the front side frame front portion 14.

  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, three or more U-shaped cross-sections 33 may be stacked in the vertical direction to constitute the main body 31 having a substantially W-shaped cross-section, thereby expanding the vertical dimension of the bumper beam 23 and causing a frontal collision. It is possible to reliably receive the collision load.

  The U-shaped cross section of the U-shaped cross section 33 includes a U-shaped cross section in which the intersections of the upper wall 33a, the lower wall 33b, and the bottom wall 33c are square.

  In the embodiment, the two U-shaped cross-sections 33 constituting the main body 31 are separately formed and joined together, but the two U-shaped cross-sections 33 are integrally molded. The main body 31 may be formed in one step.

  In addition, the initial load absorbing member 32 of the embodiment is divided into three members for facilitating manufacture, but the number of divisions is arbitrary, and it is also possible to configure with one member.

  In the embodiment, the initial load absorbing portion 32 includes the connecting wall 32a, the vertical rib 32b, and the horizontal rib 32c, but the vertical rib 32b and the horizontal rib 32c are not necessarily required.

  The bumper beam 19 of the embodiment is a front bumper beam, but the present invention can also be applied to a rear bumper beam. In that case, the input direction of the collision load is backward.

14 Front side frame front (front side frame)
18 Bumper beam extension 18a First closed section (closed section)
18b Second closed section (closed section)
18c Third closed section (closed section)
19 Bumper beam 31 Main body 32 Initial load absorbing member 32a Connecting wall 32b Vertical rib (rib)
32c Horizontal rib (rib)
33 U-shaped cross section 33a Upper wall 33b Lower wall 33c Bottom wall 33d Upper flange 33e Lower flange 33f Vertical rib 34 Fastening collar
51 Upper member
52 lower member 51b front fastening flange 51i second reinforcing rib (reinforcing rib)
52b Front fastening flange 52i Second reinforcing rib (reinforcing rib)
60 First continuous fiber 61 Second continuous fiber 81 Mounting plate 82 Bracing member

Claims (14)

At least two FRP bumper beams (19) connecting the left and right FRP bumper beam extensions (18) that are crushed by the input of the collision load extend in the vehicle width direction and open to the input side of the collision load. the have a body portion (31) having at least one substantially W-shaped cross-section U-shaped cross section portion (33) superimposed in the vertical direction, the U-shaped cross-section upper wall (33) (33a), of the lower wall (33b) and the bottom wall (33c), at least the inner surfaces of the upper wall (33a) and the lower wall (33b) are connected by a plurality of vertical ribs (33f) extending in the vertical direction. ,
The bumper beam extension (18) is configured as a combined body of the upper member (51) and the lower member (52), and is formed in a cylindrical shape by the upper member (51) and the lower member (52). a plurality of closed-section portion juxtaposed in the vehicle width direction extend in the direction (18a, 18b, 18c) comprises a vehicle width direction of the width of the bumper beam extension (18) is greater than the longitudinal width, A bumper beam for automobiles, wherein the width in the front-rear direction gradually decreases from the inside to the outside in the vehicle width direction.   The inner end of the bumper beam extension (18) in the front-rear direction is connected to a mounting plate (81) fixed to the outer end in the front-rear direction of the front side frame (14) and extending outward in the vehicle width direction. The bumper beam for an automobile according to claim 1, characterized in that (81) and the front side frame (14) are connected by a brace member (82).   The bumper beam for an automobile according to claim 1 or 2, characterized in that the bumper beam extension (18) is provided with reinforcing ribs (51i, 52i) extending in the front-rear direction.   The vertical space between the upper wall (33a) and the lower wall (33b) of the U-shaped cross section (33) is enlarged toward the input side of the collision load. Item 4. The bumper beam for automobiles according to any one of items 3 to 4.   The outer layer of the continuous fiber FRP and the inner layer of the discontinuous fiber FRP are laminated to form the U-shaped cross section (33), and the longitudinal rib (33f) is formed integrally with the inner layer of the discontinuous fiber FRP. The bumper beam for automobiles according to any one of claims 1 to 4, characterized by   The continuous fiber FRP includes a first continuous fiber (60) and a second continuous fiber (61) arranged in a direction crossing each other, and the first continuous fiber (60) is arranged in the vehicle width direction. The automobile bumper beam according to claim 5, wherein the bumper beam is an automobile.   The automobile bumper beam according to claim 6, wherein the second continuous fibers (61) are arranged in the front-rear direction or the vertical direction.   The upper wall (33a), the lower wall (33b), and the inner surface of the bottom wall (33c) of the U-shaped cross section (33) are connected by the plurality of vertical ribs (33f). The bumper beam for automobiles according to any one of claims 7 to 8.   The two U-shaped cross-sections (33) are joined by overlapping the upper flange (33d) and the lower flange (33e) to form the W-shaped cross-section main body (31). The bumper beam for automobiles according to any one of claims 1 to 8, wherein the bumper beam is for automobiles.   The fastening collar (34) for fastening the bumper beam (19) to the bumper beam extension (18) is inserted into the bottom wall (33c) of the U-shaped cross section (33). The bumper beam for automobiles according to any one of claims 1 to 9.   The bumper beam extension (18) includes upper and lower front fastening flanges (51b, 52b) that support the bumper beam (19), and the upper and lower front fastening flanges (51b, 52b) are provided on the bumper beam (19). The automobile bumper beam according to claim 10, which expands in a vertical direction toward the vehicle.   The bumper beam extension (18) includes a plurality of closed cross-section portions (18a, 18b, 18c), and the plurality of closed cross-section portions (18a, 18b, 18c) are juxtaposed in the vehicle width direction. The bumper beam for motor vehicles of Claim 10 or Claim 11.   A connection wall (32a) coupled to the main body (31) so as to close the openings of the two U-shaped cross-sections (33), and a collision load input side surface of the connection wall (32a) The initial load absorbing member (32) formed of a plurality of ribs (32b, 32c) formed in the vertical direction and extending in the vehicle width direction is provided. The bumper beam for automobiles described in 1.   The bumper beam for automobiles according to claim 13, wherein upper and lower edges of the main body (31) and upper and lower edges of the initial load absorbing member (32) are combined.

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