JP5916173B2 - Fiber-reinforced resin impact receiving member and method of manufacturing impact receiving member - Google Patents

Description

  The present invention relates to a fiber reinforced resin impact receiving member including an outer layer portion made of continuous fiber reinforced resin and an inner layer portion made of discontinuous fiber reinforced resin, and a method of manufacturing the impact receiving member.

  A stampable sheet for press-molding a bumper beam made of fiber reinforced resin for automobiles is made by impregnating a thermoplastic resin into reinforced long fibers and long fiber mats aligned in one direction. 1 is known.

  Further, it is known from Patent Document 2 below that both strength and moldability are achieved by configuring a site giving priority to strength with a continuous fiber reinforced resin and a site giving priority to moldability with a discontinuous fiber reinforced resin. .

  Further, when a glass fiber reinforced resin containing 30 to 80% by weight of glass fiber having an average length of 7 to 50 mm is preheated and molded into a product having ribs, the relationship between the rib width W and the height H is H. It is known from Patent Document 3 below that the glass fiber orientation direction in the rib is aligned with the longitudinal direction of the rib by setting so as to satisfy / W ≦ 5.

Japanese Unexamined Patent Publication No. 62-240514 Japanese Unexamined Patent Publication No. 2005-324340 Japanese Unexamined Patent Publication No. 6-293036

  By the way, when an impact receiving member such as a bumper beam to which a collision load is input is manufactured with fiber reinforced resin, its main body is formed with continuous fiber reinforced resin having high strength, and its reinforcing ribs and the like are discontinuous with high moldability. It is conceivable to mold with a fiber reinforced resin.

  However, what is described in Patent Document 1 is that continuous fiber reinforced resin containing reinforcing long fibers is arranged in the inner layer, and discontinuous fiber reinforced resin containing long fiber mats is only arranged in the outer layer. Since the resin and the discontinuous fiber reinforced resin are not properly used depending on the part, there is a problem that the characteristics of both fiber reinforced resins cannot be fully utilized.

  Moreover, since the orientation direction of the discontinuous fibers contained in the discontinuous fiber reinforced resin is random and not aligned in one direction, the one described in Patent Document 2 is applied to an impact receiving member such as a bumper beam. In such a case, there is a problem that it is difficult to cause the discontinuous fiber reinforced resin to exhibit a sufficient impact energy absorbing effect.

  Moreover, since the orientation direction of the glass fiber in the rib is along the longitudinal direction of the rib, the one described in Patent Document 3 collides with the orientation direction of the glass fiber even if it is applied to the reinforcing rib of the bumper beam. There is a problem that it is difficult to match the input direction of the load, and it is difficult to exhibit a sufficient impact energy absorbing effect. In addition, since it is necessary to set the relationship between the width W and the height H of the rib so as to satisfy H / W ≦ 5, there is a problem that a great restriction is imposed on the degree of freedom in designing the rib.

  The present invention has been made in view of the above-described circumstances, and an object of the present invention is to provide an impact receiving member that combines a continuous fiber reinforced resin and a discontinuous fiber reinforced resin with sufficient bending strength and energy absorption performance.

  In order to achieve the above object, according to the present invention, the impact receiving member has a U-shaped cross-section opened in the input direction of the collision load, in which a pair of side walls are connected to both end edges of the bottom wall facing the input direction of the collision load. Or a discontinuity comprising an outer layer portion made of continuous fiber reinforced resin formed in a U-shaped cross section, and a plurality of vertical ribs stacked on the inner surface of the outer layer portion and connected to the bottom wall and the pair of side walls. An inner layer portion made of fiber reinforced resin, and at least a part of the outer edge of the vertical rib is formed with a notch recessed in a U-shape toward the bottom wall, and the outer layer portion is The portion of the inner layer portion that constitutes the longitudinal rib includes continuous fibers oriented in the longitudinal direction of the impact receiving member, and the length of the fiber oriented in the input direction of the collision load is 35 to 50 mm. The bottom of the inner layer portion includes long fibers Portion to be laminated on the inner surface alignment directions and the fiber length at random fiber-reinforced resin impact receiving member, wherein it is proposed to include a long fiber of discontinuous fibers 35Mm～50mm.

  According to the invention, in addition to the first feature, the height of the vertical rib in the input direction of the collision load is greater than the height of the outer layer portion in the input direction of the collision load. A fiber reinforced resin impact receiving member is proposed.

  According to the invention, in addition to the first or second feature, the inner layer portion includes a lateral rib that intersects the longitudinal rib. A third feature is a fiber reinforced resin impact receiving member. Is proposed.

  According to the present invention, in addition to any one of the first to third features, a fourth feature is that the impact receiving member is disposed inside a front pillar lower continuous with the front end of the side sill. A fiber reinforced resin impact receiving member is proposed.

  According to the invention, in addition to the first feature, the impact receiving member is a bumper beam disposed in the vehicle width direction, and both ends of the bumper beam in the vehicle width direction are in the input direction of the collision load. It is supported by a vehicle body frame via a bumper beam extension having a cylindrical impact absorbing portion that extends, and the vertical ribs of the bumper beam are arranged on an extension line or a center line of the side wall portion of the impact absorbing portion. A characteristic fiber reinforced resin impact receiving member is proposed.

  According to the invention, in addition to the fifth feature, the height in the input direction of the collision load on the side wall is smaller on the outer side in the vehicle width direction than on the center side in the vehicle width direction, and the collision load input on the vertical rib is input. A fiber-reinforced resin impact receiving member having a sixth feature that the height in the direction is the same on the vehicle width direction outer side and the vehicle width direction center side is proposed.

  According to the invention, in addition to the fifth or sixth feature, the bumper beam has an isosceles triangle shape in plan view, and the width of the collision load in the input direction is maximum at the center in the vehicle width direction. A fiber reinforced resin impact receiving member having a seventh feature that it is the smallest at both ends in the width direction is proposed.

  Moreover, according to this invention, it is a manufacturing method of the impact receiving member as described in any one of said 1st-7th, Comprising: In the state which preheated the continuous fiber prepreg which comprises the said outer layer part on a female type | mold. And disposing the discontinuous fiber prepreg constituting the inner layer portion on the continuous fiber prepreg in a preheated state, and forming a groove for forming the vertical rib to form the male mold and the female mold. The manufacturing method of the impact receiving member characterized by comprising pressing the continuous fiber prepreg and the discontinuous fiber prepreg to form the impact receiving member is proposed.

  According to the invention, in addition to the eighth feature, a method for manufacturing an impact receiving member is proposed, wherein the male groove is curved in a waveform when viewed in the input direction of the collision load. Is done.

  According to the present invention, in addition to the eighth or ninth feature, an impact receiving member according to the tenth feature is characterized in that a widened portion having an enlarged groove width is formed at an opening end of the male groove. A manufacturing method is proposed.

  The bumper beams 18 and 49 of the embodiment correspond to the impact receiving member of the present invention, the vertical groove 28c of the embodiment corresponds to the groove of the present invention, and the front side frame front portion 44 of the embodiment corresponds to the present invention. Corresponding to the vehicle body frame of the invention, the first closed cross section 48a, the second closed cross section 48b, and the third closed cross section 48c of the embodiment correspond to the shock absorbing portion of the present invention.

  According to the first feature of the present invention, the impact receiving member is a continuous fiber reinforced formed in a U-shaped cross section or a U-shaped cross section in which a pair of side walls are connected to both end edges of the bottom wall facing the input direction of the collision load. An outer layer portion made of resin, and an inner layer portion made of discontinuous fiber reinforced resin, which are laminated on the inner surface of the outer layer portion and constitute a plurality of vertical ribs connected to the bottom wall and the pair of side walls. The outer layer portion includes continuous fibers oriented in the longitudinal direction of the impact receiving member, and the portion constituting the longitudinal rib of the inner layer portion is a long fiber of discontinuous fibers having a length of 35 mm to 50 mm oriented in the input direction of the collision load. Therefore, the bending of the impact receiving member due to the input of the impact load is suppressed by the outer layer portion including the continuous fibers oriented in the longitudinal direction, and the mouth opening and twisting of the impact receiving member at the time of the offset impact are suppressed on the bottom wall and the side wall. It can be suppressed by a plurality of longitudinal ribs of the inner layer portion to be connected, and the portion constituting the longitudinal rib of the inner layer portion includes long fibers having a length of 35 mm to 50 mm oriented in the input direction of the collision load. The amount of collision energy absorbed can be increased by effectively utilizing the length of the fiber.

  Further, according to the second feature of the present invention, the height of the vertical rib in the input direction of the collision load is greater than the height of the outer layer in the input direction of the collision load. Thus, energy absorption performance can be improved.

  Further, according to the third feature of the present invention, the inner layer portion includes the transverse ribs intersecting the longitudinal ribs, so that the longitudinal ribs and the transverse ribs support each other to prevent the collapse, thereby ensuring that It can be crushed to increase energy absorption performance.

  According to the fourth feature of the present invention, since the impact receiving member is disposed inside the front pillar lower connected to the front end of the side sill, the impact load input to the front pillar lower when the vehicle collides front is received. It can be effectively absorbed by the member and efficiently transmitted to the side sill for dispersion.

  According to a fifth aspect of the present invention, the impact receiving member is a bumper beam disposed in the vehicle width direction, and both ends of the bumper beam in the vehicle width direction are cylindrical impacts extending in the input direction of the collision load. The bumper beam is supported by the vehicle body frame via a bumper beam extension that has an absorber, and the bumper beam's vertical ribs are located on the extension line or center line of the side wall of the shock absorber. The energy can be reliably transmitted to the impact absorption part of the beam extension, and the energy absorption performance of the bumper beam extension can be improved.

  According to the sixth feature of the present invention, the height of the side wall in the input direction of the collision load is smaller on the outer side in the vehicle width direction than on the center side in the vehicle width direction. The height of the vertical ribs in the input direction of the collision load is the same on the vehicle width direction outer side and the vehicle width direction center side, so that the vertical ribs containing long fibers can be easily press-formed. Can do.

  According to the seventh feature of the present invention, the bumper beam has an isosceles triangle shape in plan view, and the width of the collision load in the input direction is maximum at the center in the vehicle width direction and minimum at both ends in the vehicle width direction. In the case of a frontal collision, the collision load can be input to the central portion of the bumper beam in the vehicle width direction, and the collision load can be effectively absorbed throughout the vehicle width direction of the bumper beam.

  According to the eighth aspect of the present invention, the continuous fiber prepreg constituting the outer layer portion is disposed on the female mold in a preheated state, and the discontinuous fiber prepreg constituting the inner layer portion is preliminarily disposed on the continuous fiber prepreg. Placed in a heated state and presses continuous fiber discontinuous fiber prepreg and discontinuous fiber prepreg with a male mold and a female mold having a core formed with grooves for forming vertical ribs, so that the impact receiving member is molded, so only press working In addition to molding an impact receiving member integrally comprising an outer layer portion made of continuous fiber reinforced resin and an inner layer portion made of discontinuous fiber reinforced resin, discontinuity occurs when the discontinuous fiber prepreg flows into the male groove. The long fibers of the fiber prepreg can be automatically aligned in the input direction of the collision load.

  According to the ninth feature of the present invention, the groove of the male core is curved in a waveform when viewed in the input direction of the collision load, so that when the discontinuous fiber prepreg containing long fibers flows into the groove of the core. In addition, the long fibers flow linearly in the direction in which the flow resistance is small in the groove curved in a waveform, and are efficiently oriented in the input direction of the collision load.

  Further, according to the tenth feature of the present invention, since the widened portion where the groove width is enlarged is formed at the open end of the groove of the core, the discontinuous fiber prepreg containing long fibers smoothly flows into the groove of the core. The long fibers are efficiently oriented in the input direction of the collision load.

FIG. 1 is a plan view of a front part of a vehicle body. (First embodiment) FIG. 2 is a view in the direction of the arrow 2 in FIG. (First embodiment) 3 is a cross-sectional view taken along lines 3A-3A, 3B-3B, and 3C-3C in FIG. (First embodiment) FIG. 4 is an enlarged view of part 4 of FIG. (First embodiment) 5 is a cross-sectional view taken along line 5-5 of FIG. (First embodiment) FIG. 6 is an explanatory diagram of a bumper beam forming process. (First embodiment) 7 is a cross-sectional view taken along line 7-7 of FIG. (First embodiment) FIG. 8 is a perspective view of the impact receiving member 35. (First embodiment) FIG. 9 is a diagram for explaining the operation when a collision load is input to the bumper beam. (First embodiment) FIG. 10 is a diagram for explaining how to take a test piece of rib tensile strength. (First Embodiment) FIG. 11 is a graph showing the test results of the rib tensile strength. (First embodiment) FIG. 12 is an image diagram of the discontinuous fiber alignment direction. (First embodiment) FIG. 13 is a view showing a bumper beam having a curved vertical rib. (Second Embodiment) FIG. 14 is a plan view of the front part of the vehicle body. (Third embodiment) FIG. 15 is a view in the direction of arrow 15 in FIG. (Third embodiment) 16 is a cross-sectional view taken along line 16-16 in FIG. (Third embodiment) 17 is a sectional view taken along line 17-17 in FIG. (Third embodiment)

13 Side sill 18 Bumper beam (impact receiving member)
21 Outer layer portion 21a Bottom wall 21b Side wall 21c Side wall 22 Inner layer portion 22b Horizontal rib 22c Vertical rib 27 Female die 28 Male die 28c Vertical groove (groove)
28d Widening portion 29 Continuous fiber prepreg 30 Discontinuous fiber prepreg 31 Continuous fiber 32 Discontinuous fiber 34 Front pillar lower 35 Impact receiving member 44 Front side frame front (body frame)
48 Bumper beam extension 48a First closed section (shock absorber)
48b Second closed cross section (shock absorber)
48c Third closed cross section (shock absorber)
49 Bumper beam (load receiving member)
51 Outer layer portion 51a Bottom wall 51b Side wall 51c Side wall 52 Inner layer portion 52c Vertical rib

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

First embodiment

  First, a first embodiment of the present invention will be described with reference to FIGS. In the present specification, the front-rear direction, the left-right direction (vehicle width direction), and the up-down direction are defined with reference to an occupant seated in the driver's seat. The input direction of the collision load is the front-rear direction.

  As apparent from FIGS. 1 and 2, the cabin 11 made of fiber reinforced resin integrally includes 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 in the vehicle width direction of the bumper beam 18 made of fiber reinforced resin are connected to the inner surfaces of the front end portions of the left and right bumper beam extensions 17 and 17, and a pair of left and right wheel house lower members made of fiber reinforced resin are connected to the outer surfaces of the front end portions. The front ends of 19 and 19 are connected. 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 apparent from FIGS. 2 to 4, the bumper beam 18 is formed by integrally molding an outer layer portion 21 made of continuous fiber reinforced resin and an inner layer portion 22 made of discontinuous fiber reinforced resin. The outer layer portion 21 made of continuous fiber reinforced resin is a member having a U-shaped cross section having a bottom wall 21a and a pair of side walls 21b and 21c and having an open front surface. A flange 21d faces upward from the front end of the upper side wall 21b. The flange 21e protrudes downward from the front end of the lower side wall 21c.

  The inner layer part 22 made of discontinuous fiber reinforced resin extends in the vehicle width direction on the bottom wall 21a of the outer layer part 21 and the laminated part 22a ... thinly laminated on the inner surfaces of the pair of side walls 21b, 21c. One horizontal rib 22b, a plurality of vertical ribs 22c extending in the vertical direction perpendicular to the horizontal rib 22b, and two vertical ribs 22c, 22c located at the left and right ends intersect with the horizontal rib 22b. Bosses 22e and 22e having positioning holes 22d and 22d provided, and plate-like end brackets 22f and 22f connected to the outer ends in the vehicle width direction of the lateral ribs 22b are provided. The rear edge of the horizontal rib 22b is connected to the bottom wall 21a, the rear edge and the upper and lower edges of the vertical rib 22c ... are connected to the bottom wall 21a and the side walls 21b, 21c, and the front edge of each vertical rib 22c is U-shaped. Recessed cutouts 22g are formed.

  As shown in FIG. 6A, a mold 26 for press-molding the bumper beam 18 is formed with a female mold 27 having a concave cavity 27a for molding the outer surface of the outer layer portion 21, and the inner surface of the inner layer portion 22. Are formed with a male core 28 having a convex core 28a. The core 28a is formed with horizontal grooves 28b for forming the horizontal ribs 22b and vertical grooves 28c for forming the vertical ribs 22c. In the openings of the horizontal grooves 28b and the vertical grooves 28c, widened portions 28d are formed in which the groove width is increased in a tapered shape. With the mold 26 opened, a continuous fiber prepreg 29 and a discontinuous fiber prepreg 30 are disposed in a preheated state above the cavity 27a of the female mold 27.

  The prepreg is made of woven fabric such as plain weave and twill weave made of continuous fibers such as carbon fiber, glass fiber and aramid fiber, UD (sheet in which continuous fibers are aligned in one direction), or a mat of discontinuous fibers as a reinforcing material. It is impregnated with a semi-cured thermosetting resin (such as an epoxy resin or a polyester resin) or a thermoplastic resin (such as nylon 6 or polypropylene), and has flexibility to adapt to the shape of the mold. 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.

  In the present embodiment, the reinforcing material of the continuous fiber prepreg 29 is the UD (nylon resin sheet in which continuous fibers are aligned in one direction), and the reinforcing material of the discontinuous fiber prepreg 30 is a random fiber having a fiber length of 35 mm to 50 mm. It is a nylon resin sheet of discontinuous fibers made of oriented long fibers.

  Subsequently, as shown in FIG. 6B, when the male mold 28 is lowered with respect to the female mold 27, the continuous fiber prepreg 29 is pressed by the cavity 27a of the female mold 27 and the core 28a of the male mold 28, The outer layer portion 21 of the bumper beam 18 having a U-shaped cross section is formed. At this time, since the discontinuous fiber prepreg 30 can be easily deformed, the discontinuous fiber prepreg 30 sandwiched between the continuous fiber prepreg 29 and the core 28a of the male mold 28 is thin along the inner surface of the outer layer portion 21. The laminated portions 22a of the inner layer portion 22 are formed into a film shape, and flow into the transverse grooves 28b and longitudinal grooves 28c of the core 28a, and the end portions of the transverse ribs 22b and longitudinal ribs 22c of the inner layer portion 22 The brackets 22f and 22f are formed at the same time.

  Subsequently, as shown in FIG. 6C, the bumper beam 18 is completed by cutting off the surplus portions of the flanges 21 d and 21 e of the outer layer portion 21 of the bumper beam 18 taken out from the mold 26.

  By pressing the continuous fiber prepreg 29 and the discontinuous fiber prepreg 30 with the mold 26 of FIG. 6, as shown in FIG. 4, the outer layer portion 21 of the bumper beam 18, that is, the bottom wall 21a, the upper and lower side walls 21b, 21c. The upper and lower flanges 21d and 21e are reinforced with UDs of continuous fibers 31 oriented in the longitudinal direction (vehicle width direction), which is the main stress direction of the bumper beam 18. On the other hand, the inner layer portion 22 of the bumper beam 18, that is, the laminated portion 22a, the lateral rib 22b, the longitudinal rib 22c, the bosses 22e and 22e, and the end brackets 22f and 22f are reinforced by the discontinuous fibers 32.

  When the bumper beam 18 is press-molded, the discontinuous fiber prepreg 30 placed on the female die 27 is compressed and the peripheral edge thereof is closed by the die 26, so that the lateral groove 28b and the longitudinal groove 28c on the core 28a side of the male die 28 are ... The horizontal ribs 22b and the vertical ribs 22c... Are formed by being extruded and filled. These transverse ribs 22b and longitudinal ribs 22c are aligned so that the long fibers of the discontinuous fibers 32 of the discontinuous fiber prepreg 30 face in one direction (that is, the front-rear direction which is the input direction of the collision load) from a random orientation. To do. The reason for this is, for example, the longitudinal ribs 22c ... When the long fibers of the randomly oriented discontinuous fibers 32 of the discontinuous fiber prepreg 30 flow into the longitudinal grooves 28c of the male mold 28 together with the molten resin, the molten resin Is cooled, the viscosity decreases, and the resistance between the discontinuous fibers 32 increases, so that the orientation direction of the discontinuous fibers 32 gradually changes to the inflow direction of the molten resin and is contained in the molten resin. It is estimated that the long fibers are aligned parallel to the inflow direction.

  This can be explained by comparing the tensile strength in the rib longitudinal direction and the tensile strength in the rib lateral direction, as shown in FIGS. That is, the tensile strength test shows that the tensile strength of the test pieces T1, T2, T3 in the rib lateral direction is lower than the tensile strength of the test piece T0 in the rib vertical direction, and the test pieces T1, T2 in the rib lateral direction. Since the tensile strength of T3 gradually decreases from the root side toward the tip side, the discontinuous fibers 32... Gradually move from the random state of the prepreg toward the rib tip in the direction of impact input (into the rib of the molten resin). It is estimated that they are aligned in the flow direction (see FIG. 13).

  At this time, since the widened portions 28d are formed in the openings of the horizontal grooves 28b and the vertical grooves 28c of the male mold 28 (see FIG. 6A), the discontinuous fiber prepreg 30 is male when the mold 26 is molded. It becomes possible to smoothly flow into the horizontal grooves 28b and the vertical grooves 28c of the mold 28, and the action of aligning the long fibers contained in the molten resin in parallel with the inflow direction is promoted.

  Note that only the laminated portions 22a ... laminated on the bottom wall 21a do not generate the above-described molten resin flow, so that the long fibers remain intertwined randomly (see FIG. 4).

  As shown in FIG. 5, the left and right bumper beam extensions 17, 17 made of fiber reinforced resin have an S-shaped cross section when viewed from the front, and the left and right end brackets 22 f, 22 f are the left and right bumper beam extensions 17. , 17 are bonded or welded to the inner surface in the vehicle width direction, and are further joined by rivets 33.

  As shown in FIGS. 7 and 8, a front pillar lower 34 stands up from the front end of the side sill 13, and an impact receiving member 35 made of fiber reinforced resin is accommodated inside the front pillar lower 34. The impact receiving member 35 has substantially the same structure as the bumper beam 18 described above, and is manufactured by substantially the same method.

  That is, the impact receiving member 35 is integrally provided with an outer layer portion 21 made of continuous fiber reinforced resin and an inner layer portion 22 made of discontinuous fiber reinforced resin, and the outer layer portion 21 has a bottom wall 21a bent in a square shape. And a pair of side walls 21b, 21c connected to both side edges of the bottom wall 21a and configured in a U-shaped cross section, and the inner layer portion 22 covers the bottom wall 21a and the inner surfaces of the pair of side walls 21b, 21c thinly. The laminated portion 22a, one horizontal rib 22b connected to the bottom wall 21a, and two vertical ribs 22c and 22c connected to the bottom wall 21a and the pair of side walls 21b and 21c perpendicular to the horizontal rib 22b. It consists of. The front and rear heights of the horizontal ribs 22b and the vertical ribs 22c and 22c are higher than the heights of the side walls 21b and 21c in the front-rear direction, so that the ends of the horizontal ribs 22b and vertical ribs 22c and 22c collide from the front ends of the side walls 21b and 21c. It protrudes in the load input direction.

  The bumper beam 18 is arranged with the longitudinal direction along the vehicle width direction, whereas the impact receiving member 35 is arranged with the longitudinal direction along the vertical direction. The ribs 22 c and 22 c are directed in the input direction of the collision load in the same manner as the bumper beam 18. The upper half of the bottom wall 21a is connected to the upper wall 34a of the front pillar lower 34, the lower half of the bottom wall 21a is connected to a bulkhead 36 provided at the front end of the side sill 13, and the lateral ribs 22b and the longitudinal ribs 22c are connected. , 22c is connected to the front wall 34b of the front pillar lower 34 constituting the wheel house.

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

  When the vehicle collides in front and a collision load is input to the bumper beam 18 from the front, the bending strength of the bumper beam 18 can be given to the bumper beam 18 by arranging the continuous fibers 31 of the outer layer portion 21 in the vehicle width direction. That is, as shown in FIG. 9 (A), when a bumper beam 18 having a simple U-shaped cross section without a rib collides with the front surface and deforms into a chain line state, tensile stress acts on the bottom wall 21a, and FIG. As shown in FIG. 9B, the front portions of the upper and lower side walls 21b and 21c tend to be deformed in the opening direction. The reason for this is that the bumper beam 18 has no front wall due to the U-shaped cross section, and it is difficult for compressive stress to act thereon. Therefore, by arranging the continuous fibers 31 in the main stress direction (vehicle width direction), the strength of the bumper beam 18 against bending deformation at the time of frontal collision is increased, and the bottom wall 21a and the upper and lower side walls 21b of the bumper beam 18 are increased. By connecting 21c with the longitudinal ribs 22c, the bumper beam 18 can retract and absorb an impact while generating a large reaction force without opening the mouth.

  Further, when a collision load offset in the vertical direction is input to the bumper beam 18, the bumper beam 18 is twisted and deformed as shown in FIG. 9C. By connecting the bottom wall 21a of the bumper beam 18 and the upper and lower side walls 21b, 21c with the longitudinal ribs 22c ..., the bumper beam 18 is closed and a continuous fiber inclined by 45 ° is added, which increases the weight and cost. Without reinforcing, the rigidity against torsional deformation can be sufficiently increased. The vertical ribs 22c are subjected to tensile stress in the direction orthogonal to the arrangement direction of the discontinuous fibers 32 during the opening deformation, but are absorbed by the extension of the resin.

  When a larger collision load is input to the bumper beam 18, the longitudinal ribs 22c of the inner layer portion 22 are crushed while the discontinuous fibers 32 and the resin are separated, thereby absorbing the collision energy. At this time, since the long fibers of the discontinuous fibers 32 of the longitudinal ribs 22c of the inner layer portion 22 are aligned in the input direction of the collision load, the lengths of the long fibers are effectively used and the discontinuous fibers 32. By exfoliating the resin, the amount of energy absorbed at the time of crushing can be increased.

  Further, the fiber reinforced resin of the outer layer portion 21 of the bumper beam 18 having a simple U-shaped cross section is reinforced with continuous fibers 31 with high strength, and since it has a complicated shape, it is difficult to form with continuous fibers 31. Since the bosses 22e and 22e are formed at the intersections of the lateral ribs 22b and the longitudinal ribs 22c using discontinuous fibers 32 having a high degree of freedom in molding, the strength of the bumper beam 18 and the moldability of the bosses 22e and 22e are improved. Both can be achieved. In addition, the continuous fiber prepreg 29 including the continuous fibers 31 and the discontinuous fiber prepreg 30 including the discontinuous fibers 32 are disposed in the same mold 26 to form the bumper beam 18 in one step. Manufacturing costs can be reduced as compared with the case of molding and integration by adhesion or welding.

  Further, since the length of the discontinuous fibers 32 of the inner layer portion 22 is 35 mm to 50 mm, there is a possibility that the nozzle may be clogged when trying to inject the discontinuous fibers 32 of that length together with the resin. By molding, it is possible to align the discontinuous fibers 32 of sufficient length in the ribs in the direction of impact input, and to increase the separation energy amount of the fibers and the resin of the horizontal ribs 22b and the vertical ribs 22c.

  Further, since the bosses 22e and 22e having the positioning holes 22d and 22d are provided at the intersections of the lattice-like horizontal ribs 22b and the vertical ribs 22c, positioning work when the bumper beam 18 and other parts are coupled is facilitated. . Further, the lateral rib 22b increases the strength of the bumper beam 18 itself and supports the longitudinal ribs 22c to facilitate the separation of the fibers and the resin. Further, since the end brackets 22f and 22f reinforced with the discontinuous fibers 32 are provided at both ends of the outer layer portion 21, both ends of the outer layer portion 21 can be easily coupled to the wheel house lower members 19 and 19. Further, if the positioning holes 22d and 22d are post-processed with a drill, the resin between fibers may be peeled off and the strength may be lowered. However, the bosses 22e and 22e having the positioning holes 22d and 22d are integrally formed with the bumper beam 18. Thus, the decrease in strength can be prevented.

  Further, the collision load input to the front wall 34b of the front pillar lower 34 from the front wheel retracted due to the frontal collision is transmitted to the impact receiving member 35 housed in the front pillar lower 34, and further transmitted to the front end of the side sill 13 therefrom. In addition to being dispersed, the impact receiving member 35 is crushed and the collision energy is absorbed. The action of the impact receiving member 35 at that time is the same as the action of the bumper beam 18 described above.

Second embodiment

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

  In the first embodiment, the vertical ribs 22c of the bumper beam 18 are formed in a flat plate shape. However, in the second embodiment, the vertical ribs 22c are curved in a wave shape in a front view. When the bumper beam 18 is pressed by the mold 26, the discontinuous fiber prepreg 30 flows into the lateral grooves 28b and the longitudinal grooves 28c of the male mold 28 to form the transverse ribs 22b and the longitudinal ribs 22c. The discontinuous fiber prepreg 30 that flows into the grooves 28c is most likely to flow in the direction of arrow A (impact load input direction) and less likely to flow in the direction of arrow B (direction inclined with respect to the input direction of the collision load). .

  This is because the flow path in the direction of arrow A is straight and has low flow resistance, whereas the flow path in the direction of arrow B is curved in a wave shape and has high flow resistance. Thereby, the discontinuous fiber prepreg 30 can be actively flowed in the direction of the arrow A, and the long fibers can be more accurately aligned in the input direction of the collision load.

Third embodiment

  Next, a third embodiment of the present invention will be described with reference to FIGS.

  As shown in FIG. 14, a dash panel 42 is erected from the front end of a cabin 41 integrally formed in a bathtub shape with fiber reinforced resin, and a pair of left and right suspension support members 43, 43 formed by die casting with aluminum alloy on the front surface thereof. Is fixed. The suspension support members 43 and 43 include damper housings 43a and 43a that support upper ends of suspension dampers (not shown), and front side frame rear portions 43b and 43b that are connected to lower portions of the damper housings 43a and 43a and extend forward. A pair of left and right front side frame front portions 44, 44 made of an aluminum extruded material or a steel plate press material are connected to the front ends of the front side frame rear portions 43b, 43b. A pair of left and right side members 46, 46 are connected to the front ends of a pair of left and right upper members 45, 45 extending forward from the upper left and right sides of the dash panel 42.

  A front bulkhead 47 made of a fiber reinforced resin formed in a rectangular frame shape when viewed from the front is fixed to the front ends of the front side frame front portions 44, 44, and side members 46, 46 are attached to the left and right upper portions of the front bulkhead 47. The front end of is connected. A pair of left and right bumper beam extensions 48, 48 are fixed to the left and right front surfaces of the front bulkhead 47, and a bumper beam 49 extending in the vehicle width direction is stacked in two steps vertically on the front ends of the bumper beam extensions 48, 48. 49 are fixed. A shroud 50 formed in a rectangular frame shape in front view is disposed at a position surrounded by the front bulkhead 47, bumper beams 49, 49 and a pair of left and right bumper beam extensions 48, 48, and inside the shroud 50. An unillustrated engine cooling radiator, an air conditioning condenser, and a battery cooling radiator are stacked and supported in the front-rear direction.

  As shown in FIGS. 15 to 17, the bumper beam 49 having a U-shaped cross section includes an outer layer portion 51 made of continuous fiber reinforced resin and an inner layer portion 52 made of discontinuous fiber reinforced resin. The outer layer portion 51 has a bottom wall 51 a and a pair of upper and lower side walls 51 b and 51 c and is opened forward. The outer layer portion 51 of the lower bumper beam 49 has an upper flange 51 d and an upper bumper beam 49. A flange 51e on the lower side of the outer layer portion 51 is overlapped in the front-rear direction and integrally welded to form a substantially W-shaped cross section. The inner layer portion 52 is connected to the bottom wall 51a and the pair of side walls 51b, 51c extending in the vertical direction and the bottom wall 51a and the pair of side walls 51b, 51c which are thinly laminated on the inner surface of the bottom wall 51a and the pair of side walls 51b, 51c of the outer layer portion 51. And a plurality of vertical ribs 52c. A plurality of fastening collars 53 are inserted into the bottom wall 51 a of the outer layer portion 51.

  The shape of the bumper beam 49 in plan view is an isosceles triangle, and the height in the front-rear direction is a1 that is highest at the center in the vehicle width direction and a2 that is the lowest at both ends in the vehicle width direction (FIG. 14). reference). The front edges of the two vertical ribs 52c, 52c on the vehicle width direction end side of the bumper beam 49 are on a line connecting the front ends of the pair of side walls 51b, 51c. The front edges of the other vertical ribs 52c on the side are recessed rearward from the line by notches 52d (see FIG. 15). The height in the front-rear direction of the portion excluding the notches 52d of the longitudinal ribs 52c on the center side in the vehicle width direction, and the height in the front-rear direction of the longitudinal ribs 52c not having the notches 52d on both ends in the vehicle width direction. Are consistent.

  The bumper beam 49 having the above structure can be manufactured by the same manufacturing method as the bumper beam 18 of the first embodiment. Therefore, the outer layer portion 51 of the bumper beam 49 is aligned so that the continuous fibers 31 thereof face the vehicle width direction, and the vertical ribs 52c of the inner layer portion 52 of the bumper beam 49 and the side walls 51b and 51c of the outer layer portion 51 are aligned. The laminated portions 52a covering the inner surface are aligned so that the long fibers of the discontinuous fibers 32 face the input direction (front-rear direction) of the collision load.

  The initial load absorbing members 54 covering the front surfaces of the pair of upper and lower bumper beams 49 are divided into three in the longitudinal direction of the bumper beam 49, and each has substantially the same structure. Each initial load absorbing member 54 includes a flat connecting wall 54a, and a plurality of vertical ribs 54b and a plurality of horizontal ribs 54c formed on the front surface of the connecting wall 54a. The vertical ribs 54b extending in the vertical direction and the horizontal ribs 54c extending in the left-right direction intersect with each other in a lattice shape. The upper and lower edges of the connecting wall 54a are joined to the upper and lower flanges 51d and 51e of the pair of upper and lower bumper beams 49 and 49 by adhesion or welding.

  The bumper beam extension 48 is configured by connecting an upper member 61 and a lower member 62. The upper member 61 of the bumper beam extension 48 includes a main body 61a that extends in the vehicle width direction while being bent into a corrugated plate shape, a front fastening flange 61b that is bent upward from a front edge of the main body 61a, and a rear edge of the main body 61a. A rear fastening flange 61c that bends upward from the front, and four joints 61d to 61g 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 61a. The lower member 62 is a member that is substantially vertically symmetrical with the upper member 61 described above. The upper member 61 and the lower member 62 having the above-described shapes are configured such that the pins 62k of the lower member 62 are fitted into the pin holes 61m of the upper member 61 so that the joint portions 61d to 61g and 62d to 62g are brought into contact with each other. In this state, the pins 62k... Are melted together from the upper member 61 side with a vibrating tool and are integrally coupled.

  A mounting plate 71 made of a metal plate is welded to the front end of the front side frame front portion 44, and a bracing member 72 made of a metal plate is attached to the outer end in the vehicle width direction of the mounting plate 71 and the outer surface in the vehicle width direction of the front side frame front portion 44. Is welded diagonally. Then, six bolts 73 that pass through the rear fastening flanges 61c and 62c of the bumper beam extension 48, the front bulkhead 47, and the mounting plate 71 from the front to the rear are screwed into weld nuts 74 that are provided on the rear surface of the mounting plate 71. As a result, the bumper beam extension 48 and the front bulkhead 47 are fastened together with the mounting plate 71 and joined to the front ends of the pair of left and right front side frame front portions 44, 44.

  Three nuts 63 are inserted into the front fastening flanges 61 b and 62 b of the bumper beam extension 48, and bolts 64 passing through the fastening collars 53 from the opening side of the bumper beams 49 and 49 are attached to the nut 63. The bumper beams 49 and 49 are fixed to the bumper beam extension 48 by being screwed together.

  A bumper beam extension 48 in which the upper member 61 and the lower member 62 are coupled to each other includes a rectangular tube-shaped first closed cross-sectional portion 48a 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. Second closed cross-section portion 48b and an elliptic cylindrical third closed cross-section portion 48c adjacent to the outside in the vehicle width direction. The cross-sectional areas of the second and third closed cross-section portions 48b and 48c are equal to each other and smaller than the cross-sectional area of the first closed cross-section portion 48a. Further, since the width in the front-rear direction of the bumper beam extension 48 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 section 48a, and then the second closed cross section 48b. Is long and the third closed section 48c is the shortest.

  The four vertical ribs 52c on the outer end side in the vehicle width direction of the bumper beam 49 are formed in front of both sides in the vehicle width direction of the first closed cross-sectional portion 48a of the rectangular tube shape of the bumper beam extension 48, and in the elliptical cylindrical shape. It is located on the center line of the second closed section 48b and on the center line of the third closed section 48c having an elliptical cylindrical shape (see FIG. 17).

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

  When the automobile collides front, the collision load is from the longitudinal center of the bumper beam 49 to the bumper beam extensions 48, 48 at both ends, the front side frame front portions 44, 44, and the suspension support members 43, 43, and the dash panel 42 of the cabin 41. In the process, the bumper beam extensions 48 and 48 are mainly crushed to absorb the collision energy.

  Further, the bumper beam 49 not only efficiently transmits the collision load to the left and right bumper beam extensions 48, 48 due to the high bending rigidity of the outer layer portion 51, but also collides by the vertical ribs 52c of the inner layer portion 52 being crushed. Absorb energy. The action of the bumper beam at that time is the same as the action of the bumper beam 18 of the first embodiment.

  In addition, since the entire opening of the bumper beam 49 that opens toward the front is closed by the connecting wall 54a of the initial load absorbing member 54, the bumper beam 49 is completely closed to increase the strength, and the impact load is reduced to the bumper beam. It can be efficiently transmitted to the extension 48.

  Further, the bumper beam 49 has a longitudinal rib 52c at the center side in the vehicle width direction, the front edge of which is cut out from the line connecting the tips of the pair of side walls 51b and 51c toward the bottom wall 51a. The front edge of 52c ... is along a line connecting the ends of the pair of side walls 51b, 51c, so that the outer layer portion 51 is prevented from opening at the center in the vehicle width direction of the bumper beam 49 and the energy absorption effect is ensured. It can be demonstrated.

  Further, the bumper beam 49 has an isosceles triangle shape in plan view, and the height of the collision load in the input direction is smaller in the vehicle width direction outer side than in the vehicle width direction central side. Not only can it conform to the plane shape without difficulty, but also the collision load can be input to the central portion in the vehicle width direction of the bumper beam 49 at the time of a frontal collision, and the collision load can be effectively absorbed in the entire vehicle width direction of the bumper beam 48. Can do. Moreover, since the heights of the longitudinal ribs 52c in the input direction of the collision load are the same on the vehicle width direction outer side and the vehicle width direction center side, the vertical ribs 52c including the long fibers can be easily press-formed.

  Further, both end portions in the vehicle width direction of the bumper beam 49 are supported by the front side frame front portion 44 via a bumper beam extension 48 having first to third closed cross-section portions 48a, 48b, and 48c extending in the collision load input direction. The vertical ribs 52c of the bumper beam 49 are disposed on the extension line of the side wall portion of the first closed cross section 48a and on the center lines of the second closed cross section 48b and the third closed cross section 48c. Can be reliably transmitted to the first to third closed cross sections 48a, 48b, 48c of the bumper beam extension 48, and the energy absorption performance of the bumper beam extension 48 can be enhanced.

  The initial load absorbing member 54 that closes the opening of the bumper beam 49 includes a connecting wall 54a, and a large number of vertical ribs 54b and a large number of horizontal ribs 54c formed on the outer surface in the front-rear direction of the connecting wall 54a. By collapsing the vertical ribs 54b and the large number of horizontal ribs 54c, the initial collision load at the time of frontal collision can be efficiently absorbed.

  Further, since the upper and lower pair of bumper beams 49 and 49 are joined with the upper flange 51d and the lower flange 51e being overlapped, the mold 26 is compared with the case where the pair of upper and lower bumper beams 49 and 49 are integrally formed. Can be reduced in size, and the disturbance in the orientation direction of the continuous fibers 31 of the bumper beam 49 can be minimized to ensure the strength.

  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 impact receiving member of the present invention is not limited to those disposed in the bumper beams 18 and 49 and the front pillar lower 34 of the embodiment, and can be applied to any part of a vehicle body such as a door beam. it can.

  Further, instead of overlapping a pair of bumper beams 49, 49 having a U-shaped cross section in the vertical direction, they may be integrally formed so as to have a W-shaped cross section.

Claims (10)

The impact receiving member (18, 35, 49) has a pair of side walls (21b, 21c, 51b, 51c) connected to both end edges of the bottom wall (21a, 51a) facing the input direction of the collision load. An outer layer portion (21, 51) made of continuous fiber reinforced resin formed in a U-shaped cross section or a U-shaped cross section that is open to the bottom, and the bottom wall is laminated on the inner surface of the outer layer portion (21, 51) (21a, 51a) and a plurality of longitudinal ribs (22c, 52c) connected to the pair of side walls (21b, 21c, 51b, 51c) and inner layers (22, 52) made of discontinuous fiber reinforced resin. A notch (22g, 52d) recessed in a U-shape toward the bottom wall (21a, 51a) is formed at an outer edge of at least a part of the vertical rib (22c, 52c). And
The outer layer portion (21, 51) includes continuous fibers (31) oriented in the longitudinal direction of the impact receiving member (18, 35, 49),
The portion of the inner layer portion (22, 52) that constitutes the longitudinal rib (22c, 52c) is a long fiber of discontinuous fibers (32) having a fiber length of 35 mm to 50 mm oriented in the input direction of the collision load. In addition, the portion of the inner layer portion (22, 52) laminated on the inner surface of the bottom wall (21a, 51a) is a discontinuous fiber (32) whose orientation direction is random and whose fiber length is 35 mm to 50 mm. A fiber reinforced resin impact receiving member comprising long fibers.   The fiber-reinforced resin impact according to claim 1, wherein the height of the longitudinal rib (22c) in the input direction of the collision load is greater than the height of the outer layer portion (21) in the input direction of the collision load. Receiving member.   The fiber reinforced resin impact receiving member according to claim 1 or 2, wherein the inner layer portion (22) includes a lateral rib (22b) that intersects the longitudinal rib (22c).   The fiber according to any one of claims 1 to 3, wherein the impact receiving member (35) is arranged inside a front pillar lower (34) connected to the front end of the side sill (13). Reinforced resin impact receiving member.   The impact receiving member is a bumper beam (49) disposed in the vehicle width direction, and both end portions in the vehicle width direction of the bumper beam (49) are cylindrical impact absorbing portions (48a) extending in the input direction of the collision load. A vertical rib (52c) of the bumper beam (49) is supported on an extension line or a center line of the side wall portion of the shock absorber (48a). The fiber reinforced resin impact receiving member according to claim 1, wherein the impact receiving member is disposed.   The height in the input direction of the collision load of the side walls (51b, 51c) is smaller than the center side in the vehicle width direction outside in the vehicle width direction, and the height in the input direction of the collision load of the vertical rib (52c) is in the vehicle width direction. 6. The impact receiving member made of fiber reinforced resin according to claim 5, wherein the impact receiving member is the same on the outer side and the center side in the vehicle width direction.   The bumper beam (49) has an isosceles triangle shape in plan view, and the width of the collision load in the input direction is maximum at the center in the vehicle width direction and minimum at both ends in the vehicle width direction. Or the fiber reinforced resin impact receiving member of Claim 6.   It is a manufacturing method of the impact receiving member (18) of any one of Claims 1-6, 8, Comprising: The continuous fiber prepreg which comprises the said outer layer part (21) on a female type | mold (27) ( 29) is disposed in a preheated state, and the discontinuous fiber prepreg (30) constituting the inner layer portion (22) is disposed on the continuous fiber prepreg (29) in a preheated state; The continuous fiber prepreg (29) and the discontinuous fiber prepreg (30) are pressed by the male mold (28) in which the groove (28c) for forming the rib (22c) is formed and the female mold (27) to press the continuous fiber prepreg (30). And a step of forming the impact receiving member (18).   10. The method of manufacturing an impact receiving member according to claim 9, wherein the groove (28c) of the male mold (28) is curved in a waveform when viewed in the input direction of the collision load.   11. The impact receiving member according to claim 9, wherein a widened portion (28 d) having an increased groove width is formed at an opening end of the groove (28 c) of the male mold (28). Method.

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