JP6125482B2 - Automotive bumper - Google Patents

Description

  The present invention comprises a bumper beam made of fiber reinforced resin arranged in the vehicle width direction, and a pair of left and right fiber reinforced resin bumper beam extensions arranged in the front-rear direction and supporting both ends of the bumper beam in the vehicle width direction. The present invention relates to an automotive bumper.

  The shock absorbing structure constituting the front bumper beam is formed in the vehicle width direction while curving convexly forward between the pair of left and right stays protruding from the front ends of the pair of left and right front side frames and the front ends of the pair of left and right stays. Constructed with a curved member made of pipe material to be connected, which prevents unnecessary deployment of the airbag by easily plastically deforming the shock absorbing structure at the time of light collision to prevent sudden deceleration Is known from Patent Document 1 below.

  Also, a pair of left and right fiber reinforced resin bumper beam extensions extending in the front-rear direction are connected in series to the front ends of a pair of left and right metal front side frames extending in the front-rear direction, and the vehicle width direction of the front ends of the pair of left and right bumper beam extensions A technique in which both ends in the vehicle width direction of a bumper beam made of a fiber reinforced resin extending in the vehicle width direction is connected between the inner surfaces is known.

Japanese Patent Laid-Open No. 10-230865 WO2013 / 0994515

  By the way, what is described in the above-mentioned Patent Document 1 does not deploy the airbag even when a collision load is input to the shock absorbing structure, and then deploys the airbag for the first time when the collision load is input to the front side frame. For this reason, there is a possibility that the deployment of the airbag is delayed and sufficient occupant restraint performance cannot be exhibited, and the impact absorbing structure is easily deformed, resulting in insufficient energy absorption.

  Further, in the above-mentioned Patent Document 2, when a large collision load is input to the bumper beam and a bending moment acts on the front end of the bumper beam extension, the outer end in the vehicle width direction of the bumper beam is the vehicle width of the bumper beam extension. Since it is only connected to the inner surface in the direction with rivets, the strength of the connecting portion may be insufficient, and the bumper beam bending moment may not be supported at the front end of the bumper beam extension.

  The present invention has been made in view of the above-described circumstances, and enables the bending moment generated in the bumper beam due to the collision load to be supported by the bumper beam extension, and generates an appropriate deceleration for operating the airbag. With the goal.

In order to achieve the above object, according to the invention described in claim 1, a bumper beam made of fiber reinforced resin arranged in the vehicle width direction and both ends of the bumper beam in the vehicle width direction arranged in the front-rear direction. a motor vehicle bumper and a pair of left and right fiber-reinforced resin bumper beam extension for supporting the front Symbol bumper beam, a bottom wall, cross co which opens in the longitudinal direction inside a top wall and a lower wall A two-layer structure in which the bumper beam is formed by laminating a continuous fiber reinforced resin layer and a discontinuous fiber reinforced resin layer. The continuous fiber reinforced resin layer includes continuous fibers oriented over the entire length in the vehicle width direction and continuous fibers oriented in a direction orthogonal to the vehicle width direction, and the discontinuous fiber reinforced resin layer With the extension in the longitudinal direction in the end front and rear folded toward the outside of the continuous fiber-reinforced the top wall while surrounding the end portion of the resin layer and the lower wall, the bumper beam extension formed in the hollow closed section, the A bumper for an automobile is proposed, which includes an inclined portion that is inclined along the bottom wall at an outer end in the front-rear direction that is fitted and fixed to the inclined portion of the bumper beam from the inner side in the front-rear direction .

According to the first aspect, VA Npabimu the bottom wall is formed in a U-shaped cross section that opens in the front-rear direction inner side comprises an upper wall and a lower wall, a front-rear direction inner side in the vehicle widthwise ends The bumper beam extension, which has an inclined part that slopes toward the bottom and is formed in a hollow closed cross section, is inclined along the bottom wall at the outer front / rear end, which is fitted and fixed to the inclined part of the bumper beam from the front / rear inner side. The bumper beam and the bumper beam extension are firmly connected, and the bending moment acting on the bumper beam when a collision load is input can be efficiently supported by the bumper beam extension. Since the collapse of the extension starts from the tip of the inclined part and moves to a constant cross-sectional area, it is possible to absorb shock from the beginning of the collision And not only can increase the energy absorption amount can be properly deployed by early and reliably detect the occurrence of a collision by generating a vehicle deceleration from the initial stage of the collision airbag for the passenger.

The bumper beam is a two-layer structure in which a continuous fiber reinforced resin layer and a discontinuous fiber reinforced resin layer are laminated.
The continuous fiber reinforced resin layer includes continuous fibers oriented over the entire length in the vehicle width direction and continuous fibers oriented in a direction perpendicular to the vehicle width direction, and the discontinuous fiber reinforced resin layer is continuous. Since it has an extension that folds the front and rear inner ends of the upper and lower walls back and forth while enclosing the end of the fiber reinforced resin layer, cracks due to stress concentration occur at the end of the continuous fiber reinforced resin layer. Can be easily formed by the discontinuous fiber reinforced resin layer excellent in moldability.

The top view of the vehicle body front part of a motor vehicle. (First embodiment) FIG. 2 is an enlarged view of part 2 of FIG. 1. (First embodiment) FIG. 3 is a three-direction arrow view of FIG. 2. (First embodiment) FIG. 4 is a four-direction arrow view of FIG. 2. (First embodiment) FIG. 5 is a sectional view taken along line 5-5 of FIG. (First embodiment) FIG. 6 is a sectional view taken along line 6-6 of FIG. (First embodiment) FIG. 7 is a sectional view taken along line 7-7 in FIG. (First embodiment) The figure which shows the crushing state of a bumper beam extension. (First embodiment) The figure which shows the relationship between the deformation amount of a bumper beam extension, and a load. (First embodiment) The figure which shows the press-molding die of a bumper beam. (First embodiment) Explanatory drawing of the formation process of the extension part of a bumper beam. (First embodiment) The figure which shows the press-molding die of a bumper beam extension. (First embodiment) The figure which shows other embodiment of a metal gusset. (Second to fourth embodiments)

First embodiment

  Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. In the present specification, the front-rear direction, the left-right direction (vehicle width direction), and the up-down direction are defined with reference to an occupant seated in the driver's seat. The bumper of the present invention includes both a front bumper and a rear bumper. Hereinafter, the front bumper will be described as an example.

  As shown in FIGS. 1 to 5, the front bumper 11 provided at the rear of the vehicle body has a bumper beam 12 made of fiber reinforced resin extending in the vehicle width direction, and a front end connected to the rear surfaces of both ends of the bumper beam 12 in the vehicle width direction. And a pair of left and right fiber reinforced resin bumper beam extensions 13, 13 and a pair of left and right metal gussets 14, 14 connecting the bumper beam 12 and the pair of left and right bumper beam extensions 13, 13. A front end of a metal front side frame 15 is connected to a rear end of the beam extension 13 in the vehicle width direction, and an upper member 16 extending from the front pillar is connected to a rear end of the bumper beam extension 13 in the vehicle width direction. The front end is connected.

  The radiator 40 of the engine and the condenser 41 of the air conditioner are slidable in the front-rear direction at a position behind the bumper beam 12 and sandwiched between the pair of left and right metal gussets 14, 14 (see FIG. 1).

  The bumper beam 12 includes a beam portion 17 having a substantially constant cross-sectional area sandwiched between inner ends in the vehicle width direction of the pair of left and right bumper beam extensions 13 and 13, and extends outward in the vehicle width direction from both ends of the beam portion 17 in the vehicle width direction. And a pair of left and right inclined portions 18 and 18 supported at the front ends of the bumper beam extensions 13 and 13. The inclined portion 18 is inclined outward in the vehicle width direction, the sectional area S2 of the inclined portion 18 is smaller than the sectional area S1 of the beam portion 17, and the sectional area S2 of the inclined portion 18 is outside in the vehicle width direction. It gradually decreases toward (see FIG. 1).

  The bumper beam 12 includes a bottom wall 12a facing in the front-rear direction, an upper wall 12b extending rearward from the upper end of the bottom wall 12a, and a lower wall 12c extending rearward from the lower end of the bottom wall 12a, and is opened rearward. It is formed in a U-shaped cross section (see FIG. 5). Further, the bumper beam 12 includes extension portions 12e and 12e in which the reinforcing portions 12d and 12d at the rear ends of the upper wall 12b and the lower wall 12c are folded forward in a flange shape. The front-rear direction width of the extension portion 12e is the largest d1 at the center of the beam portion 17 in the vehicle width direction, and gradually decreases from there toward the outer end in the vehicle width direction of the beam portion 17, and the extension portion 12e has a very small d2. (See FIG. 2).

  The bottom wall 12a, the upper wall 12b, and the lower wall 12c of the bumper beam 12 are a laminate in which a continuous fiber reinforced resin layer 19 constituting the outer surface and a discontinuous fiber reinforced resin layer 20 constituting the inner surface are laminated in two layers. It has a structure (see FIG. 5). The continuous fiber reinforced resin layer 19 is obtained by reinforcing a continuous fiber oriented in the vehicle width direction and a continuous fiber oriented in a direction (vertical direction and front-rear direction) perpendicular thereto with a thermoplastic resin. The length of the oriented continuous fiber is the length of the bumper beam 12 reaching from the one end to the other end in the vehicle width direction. The discontinuous fiber reinforced resin layer 20 is obtained by reinforcing randomly oriented continuous fibers having a length of about 50 mm with a thermoplastic resin.

  The end portions of the continuous fiber reinforced resin layer 19 end at the rear ends of the upper wall 12b and the lower wall 12c, and the end portions are covered with the discontinuous fiber reinforced resin layer 20 to constitute the reinforcing portion 12d. Further, the extended portion 12e obtained by folding the reinforcing portion 12d forward in a flange shape is composed of the discontinuous fiber reinforced resin layer 20 (see FIG. 5). Further, on the inner surface of the beam portion 17 of the bumper beam 12, a pair of left and right reinforcing ribs 12f and 12f that connect the bottom wall 12a, the upper wall 12b, and the lower wall 12c in the vertical direction are provided near the end of the metal gusset 14 described later. It is integrally formed on the center side (see FIGS. 2 and 4).

  The bumper beam 12 having such a structure can be press-molded using a press-molding die 21 shown in FIG.

  The press mold 21 includes a female mold 22 having a concave cavity 22a for molding the continuous fiber reinforced resin layer 19 and a male mold 23 having a convex core 23a for molding the discontinuous fiber reinforced resin layer 20. . After the press-forming mold 21 is opened, the continuous fiber prepreg 19 'and the discontinuous fiber prepreg 20' are disposed in a preheated state between the cavity 22a of the female mold 22 and the core 23a of the male mold 23. The bumper beam 12 is press-molded by clamping the press-molding die 21.

  At this time, since the discontinuous fibers are included, the reinforcing ribs 12f and 12f and the extending portion 12e can be integrally formed by the discontinuous fiber reinforced resin layer 20 having high moldability. The extension portion 12e is formed by the melted discontinuous fiber prepreg 20 'flowing into the cavity 22b (see FIG. 11) of the female mold 22, but the end portion of the discontinuous fiber reinforced resin layer 20 is previously formed in the reinforcing portion 12d. By curving to the extension part 12e side, the melted discontinuous fiber prepreg 20 'can smoothly flow into the cavity 22b and the extension part 12e can be easily molded.

  As shown in FIGS. 2 to 4, 6, and 7, the bumper beam extension 13 has a horizontally long rectangular tube shape by connecting an upper half body 24 that opens downward and a lower half body 25 that opens upward. It is configured with a hollow closed cross section. The upper half 24 has a laminated structure in which a continuous fiber reinforced resin layer 26 constituting an inner surface and a discontinuous fiber reinforced resin layer 27 constituting an outer surface are laminated in two layers (see FIGS. 6 and 7). The continuous fiber reinforced resin layer 26 includes at least continuous fibers oriented in the front-rear direction and continuous fibers oriented in a direction (vehicle width direction and vertical direction) orthogonal to the front-rear direction.

  The upper half 24 includes two reinforcing ribs 24b and 24b extending in the front-rear direction on the upper wall 24a, and one reinforcing groove 24c sandwiched between the two reinforcing ribs 24b and 24b. One reinforcing rib 24d extending in the front-rear direction is provided at the outer end in the direction. A vehicle body mounting seat 24e connected to the two reinforcing ribs 24b, 24b is formed at the rear end of the upper half body 24, and three metal bushes 29 are embedded in the vehicle body mounting seat 24e. The reinforcing ribs 24b and 24b, the reinforcing rib 24d, and the vehicle body mounting seat 24e are integrally formed of a discontinuous fiber reinforced resin layer 27.

  The upper half body 24 having such a structure can be press-molded using a press-molding die 30 shown in FIG.

  The press molding die 30 includes a female die 31 having a concave cavity 31a for molding the discontinuous fiber reinforced resin layer 27, and a male die 32 having a convex core 32a for molding the continuous fiber reinforced resin layer 26. . After the press mold 30 is opened, the continuous fiber prepreg 26 ′ and the discontinuous fiber prepreg 27 ′ are placed between the cavity 31 a of the female mold 31 and the core 32 a of the male mold 32 in a preheated state. The upper half body 24 is press-molded by clamping the press-molding die 30. At this time, when partially thickening, the thickness of the continuous fiber prepreg 26 'or the discontinuous fiber prepreg 27' may be partially increased. The reinforcing ribs 24b, 24b, the reinforcing ribs 24d, and the vehicle body mounting seat 24e can be easily formed by the discontinuous fiber reinforced resin layer 27 having high formability because the discontinuous fibers are included.

  The lower half 25 is substantially symmetrical with the upper half 24 and includes a lower wall 25a, reinforcing ribs 25b and 25b, reinforcing grooves 25c, reinforcing ribs 25d, and a vehicle body mounting seat 25e. And press-molded in the same manner as the upper half 24.

  The inner ends in the vehicle width direction of the upper half 24 and the lower half 25 are overlapped and bonded in the vehicle width direction and fastened with rivets (not shown), and the upper half 24 and the lower half 25 are outside in the vehicle width direction. The upper half body 24 and the lower half body 25 are joined together by fastening the plurality of flanges 24f, 25f in the vertical direction and fastening them with a plurality of rivets 33. Further, bolts 34 penetrating the metal bushes 29 embedded in the vehicle body mounting seats 24e, 25e of the upper half 24 and the lower half 25 from the front to the rear further connect the front side frame 15 and the front end of the upper member 16. The rear end of the bumper beam extension 13 is coupled to the front ends of the front side frame 15 and the upper member 16 by passing through the flange 35 and screwing into the nuts 36.

  The bumper beam extension 13 includes a triangular inclined portion 13a located at the tip of the bumper beam extension 13 and a constant cross-sectional area portion 13b continuing to the rear thereof. The inclined portion 13a of the bumper beam extension 13 is a bumper beam 12 having a U-shaped cross section. The upper wall 12b of the bumper beam 12 and the bumper beam are fitted with the inclined portion 18 of the bumper beam extension 13 from behind, with the tip of the inclined portion 13a of the bumper beam extension 13 being substantially abutted against the inner surface of the bottom wall 12a of the bumper beam 12. The upper wall 24a of the extension 13 is fastened by a plurality of rivets 37, and the lower wall 12c of the bumper beam 12 and the lower wall 25a of the bumper beam extension 13 are fastened by a plurality of rivets 37.

  At this time, since the inclined portion 18 of the bumper beam 12 is inclined rearward in the vehicle width direction, the inclined portion 13a of the bumper beam extension 13 is similarly inclined backward in the vehicle width direction (FIG. 2). reference).

  As shown in FIGS. 2, 4 and 5, the metal gusset 14 connecting the bumper beam 12 and the bumper beam extension 13 is formed by press-molding a single metal plate, and extends in the vehicle width direction to extend the bumper beam 12. A first fixing portion 14a fastened to the inner surface of the bottom wall 12a of the beam portion 17 by a plurality of rivets 38 ... and a plurality of rivets 39 ... extending in the front-rear direction and extending in the vehicle width direction inner walls 24g, 25g of the bumper beam extension 13. A second fixing portion 14b to be fastened and an intermediate portion 14c inclined from the outer end in the vehicle width direction of the first fixing portion 14a toward the front end of the second fixing portion 14b. The intermediate portion 14c and the second fixing portion 14b The bent portion 14d is formed at the boundary.

  The vertical cross section of the metal gusset 14 is constant over the first fixing portion 14a, the intermediate portion 14c, and the second fixing portion 14b, and includes a pair of upper and lower flanges a and b and a reinforcing groove c in the middle in the vertical direction. And bent (see FIG. 5).

  As shown in FIGS. 2 and 7, the thickness of the continuous fiber reinforced resin layer 26 is partially larger at the inner side in the vehicle width direction than the reinforcing grooves 24 c and 25 c of the bumper beam extension 13 as compared with other portions. The first thick plate portion 13c and the bumper beam extension 13 on the outer side in the vehicle width direction of the reinforcing ribs 24b and 25b on the outer side in the vehicle width direction, the portions adjacent to the vehicle body mounting seats 24e and 25e are other portions. The thickness of the discontinuous fiber reinforced resin layer 27 is partially increased (second thick plate portion 13d). These first and second thick plate portions 13c and 13d are shown shaded in FIG.

  Note that the continuous fiber reinforced resin layer 26 is partially made thicker than the reinforcing ribs 24b, 25b on the outer side in the vehicle width direction of the bumper beam extension 13 compared to the reinforcing groove 24c on the outer side in the vehicle width direction. Absorption performance may be improved.

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

  In FIG. 2, the bumper beam 12 including continuous fibers oriented along the entire length in the vehicle width direction and having a bottom wall 12a, an upper wall 12b, and a lower wall 12c and having a U-shaped cross section is highly bent. Has strength. When a collision load of frontal collision is input to the bumper beam 12, the bumper beam 12 is connected between the pair of left and right inclined portions 18 and 18 connected to the front ends of the pair of left and right bumper beam extensions 13 and the pair of left and right inclined portions 18 and 18. And the inclined portions 18 and 18 are inclined rearward in the vehicle width direction and smaller in cross-sectional area than the beam portion 17, so that the collision load is caused by the beam portion 17 having a large cross-sectional area. In addition to supporting, the collision load can be reliably transmitted to the bumper beam extensions 13 and 13 from the pair of left and right inclined portions 18 and 18, and the collision energy can be absorbed by the collapse of the bumper beam extensions 13 and 13.

  Further, when a collision load of a frontal collision is input, a bending moment acts on the bumper beam 12, but the front end of the bumper beam extension 13 formed in the hollow closed cross section is fitted to the inclined portion 18 of the bumper beam 12 from the rear, and the rivet 37 ... being fixed, the bumper beam 12 and the bumper beam extension 13 can be firmly coupled to efficiently support the bending moment.

  In addition, the bumper beam extension 13 includes an inclined portion 13a whose outer side in the vehicle width direction is inclined rearward, and the inclined portion 13a is substantially abutted against the rear surface of the bottom wall 12a of the inclined portion 18 of the bumper beam 12. When a collision load is input, the collapse of the bumper beam extension 13 starts from the tip of the inclined part 13a and shifts to the constant cross-sectional area part 13b, thereby enabling shock absorption from the beginning of the collision and increasing the amount of energy absorption. Not only can the vehicle body be decelerated from the beginning of the collision, but the occurrence of the collision can be detected early and reliably, and the airbag can be appropriately deployed.

  More specifically, as shown in FIG. 8, when a collision load is input to the inclined portion 13a at the front end of the bumper beam extension 13, the continuous fiber reinforced resin layer 26 is sequentially delaminated from the tip side of the inclined portion 13a. The collapsing energy is absorbed by crushing, and further, the delamination of the constant cross-sectional area portion 13b behind the inclined portion 13a proceeds and the collapsing energy is absorbed.

  As shown in FIG. 9, the stroke at the tip of the inclined portion 13a of the bumper beam extension 13 is S0, and the stroke at the position where the width of the first thick plate portion 13c inside the vehicle width direction of the bumper beam extension 13 becomes constant is S1. Assuming that the stroke of the front end of the constant cross-sectional area 13b of the bumper beam extension 13 is S2, when the crushing stroke of the bumper beam extension 13 proceeds from S0 to beyond S1 and S2, the load applied to the bumper beam extension 13 is It changes as shown by the solid line.

  That is, in the range from the stroke S0 to S1, the load suddenly rises because the cross-sectional area of the first plank portion 13c gradually increases, and the range from the stroke S1 to S2 is the range of the first plank portion 13c. Since the cross-sectional area becomes constant and the cross-sectional area of the thin plate portion gradually increases, the load rises slowly. In the range after the stroke S2, the constant cross-sectional area portion 13b of the bumper beam extension 13 is crushed and the load is constant. Value. The characteristics of the upper and lower chain lines indicate the respective threshold values of the upper limit value and the lower limit value for operating the passenger airbag, and the load characteristics of the present embodiment are between the upper limit value and the lower limit value in all areas. Therefore, it is possible to generate a deceleration that reliably deploys the airbag.

  The characteristic of the broken line A is the case where the bumper beam extension 13 does not include the first thick plate portion 13c, and there is a possibility that the airbag does not deploy because the load falls below the lower limit value of the threshold value in the latter half of the collision. Further, the characteristics of the broken line B are those in the case where all the inclined portions 13a of the bumper beam extension 13 are provided with the first thick plate portion 13c, and the airbag does not deploy because the load exceeds the upper limit value of the threshold from the initial stage of the collision to the middle stage of the collision there is a possibility.

  As described above, according to the present embodiment, the first thick plate portion 13c on the inner side in the vehicle width direction of the bumper beam extension 13 is larger than the plate thickness on the outer side portion in the vehicle width direction. The first thick plate portion 13c having a large plate thickness generates a deceleration for actuating the airbag, and an excessive deceleration that causes a burden on the occupant at the outer portion in the vehicle width direction where the plate thickness that collapses late is small. In addition, the bumper beam extension 13 can be reduced in weight.

  The bumper beam 12 has a two-layer structure in which an outer continuous fiber reinforced resin layer 19 and an inner discontinuous fiber reinforced resin layer 20 are laminated, and the continuous fiber reinforced resin layer 19 includes continuous fibers oriented in the vehicle width direction, The discontinuous fiber reinforced resin layer 20 includes continuous fibers oriented in a direction orthogonal to the vehicle width direction, and the upper wall 12b and the lower wall 12c surround the end portion (reinforcing portion 12d) of the continuous fiber reinforced resin layer 19. Discontinuous fiber reinforced resin because cracks due to stress concentration occur at the end portion (reinforcing portion 12d) of the continuous fiber reinforced resin layer 19 because the extension portion 12e is provided with the front and rear ends folded back to the front outer side (see FIG. 5). The extension portion 12e that suppresses by the layer 20 and increases the sectional moment of the bumper beam 12 can be easily formed by the discontinuous fiber reinforced resin layer 20 having excellent moldability.

  Moreover, since the width of the extension 12e gradually decreases from d1 at the center in the vehicle width direction of the bumper beam 12 to d2 at both ends in the vehicle width direction (see FIG. 2), the second moment of section of the bumper beam 12 is increased by the extension 12e. Thus, not only can the bending strength be increased, but also when the bolts 34... For attaching the bumper beam 12 to the bumper beam extension 12 are operated, the workability is improved because the extension 12e does not interfere with the operation of the tool.

  Further, the bumper beam 12 includes a beam portion 17 sandwiched between a pair of left and right inclined portions 18, 18, and the cross-sectional area of the beam portion 17 is larger than the cross-sectional area of the pair of left and right inclined portions 18, 18. Can be reliably transmitted to the bumper beam extensions 13 and 13 from the pair of left and right inclined portions 18 and 18, and the collision energy can be absorbed by the collapse of the bumper beam extensions 13 and 13.

  At this time, the bumper beam extension 13 has a two-layer structure in which an inner continuous fiber reinforced resin layer 26 and an outer discontinuous fiber reinforced resin layer 27 are laminated, and the upper wall 24 a and the lower wall 25 a are above the bumper beam 12. Since the rivets 37 are mechanically joined to the wall 12b and the lower wall 12c respectively, the load transmission from the bumper beam 12 to the bumper beam extension 13 is ensured to improve the collision energy absorption performance and The inner continuous fiber reinforced resin layer 26 reinforced so as to suppress out-of-plane deformation by the continuous fiber reinforced resin layer 27 can be crushed from the center to absorb the collision energy.

  Further, since the bumper beam extension 13 has a horizontally long hollow closed cross section in which the width in the vehicle width direction is larger than the width in the vertical direction, the shock absorbing characteristics can be increased by increasing the degree of freedom in setting the size of the first thick plate portion 13c. The degree of freedom of setting can be increased. Moreover, since the bumper beam extension 13 includes reinforcing ribs 24b, 24b, 25b, 25b and reinforcing grooves 24c, 25c made of the discontinuous fiber reinforced resin layer 27 on the upper wall 24a and the lower wall 25a, the bumper beam extension 13 is provided. When the collision load is input to the inclined portion 13a, the out-of-plane deformation of the upper wall 24a and the lower wall 25a is suppressed, and the bumper beam extension 13 is sequentially crushed from the front end toward the rear end to improve the collision energy absorption performance. be able to. Furthermore, since the bumper beam extension 13 includes the vehicle body mounting seats 24e and 25e made of the discontinuous fiber reinforced resin layer 27 at the rear end thereof, the bumper beam extension 13 can be easily attached to the vehicle body.

  The metal gusset 14 that reinforces the connection between the bumper beam 12 and the bumper beam extension 13 includes a first fixing portion 14a that extends in the vehicle width direction and is fixed to the rear surface of the bumper beam 12, and a bumper beam extension that extends in the front-rear direction. 13 includes a second fixing portion 14b fixed to the inner surface in the vehicle width direction, and an intermediate portion 14c that obliquely connects the first fixing portion 14a and the second fixing portion 14b, so that the bumper beam 12 and the bumper beam at the initial stage of the collision The connecting portion of the extension 13 is reinforced with the metal gusset 14 to reduce the bending moment, and the bending portion 14d bends and deforms to absorb the collision energy, thereby supporting a large collision load while reducing the weight of the bumper beam 12. Is possible.

  In particular, the metal gusset 14 is easy to ensure a constant cross-section over its entire length, so that the amount of energy absorption at the time of deformation is increased by bending or curving its vertical cross-section to increase the cross-sectional moment. Further, in the latter half of the collision, the intermediate portion 14c of the metal gusset 14 buckles, and at the same time, the fiber and the resin of the bumper beam extension 13 are separated and broken, and the amount of collision energy absorbed increases due to the synergistic effect.

  Moreover, the bumper beam extension 13 includes a continuous fiber reinforced resin layer 26 in which continuous fibers are oriented in the front-rear direction and a direction perpendicular thereto, and is mechanically coupled to the second fixing portion 14b of the metal gusset 14 via rivets 39. Therefore, the load transmission from the metal gusset 14 to the bumper beam extension 13 is ensured to improve the impact energy absorption performance, and the continuous fiber reinforced resin layer 26 is delaminated and cracked to be crushed and collided. Can be absorbed.

  Further, the discontinuous fiber reinforced resin layer 20 of the bumper beam 12 includes a reinforcing rib 12f extending in the vertical direction on the center side in the vehicle width direction in the vicinity of the joint portion of the metal gusset 14 with the first fixing portion 14a (see FIG. 2 and FIG. 2). 4), by preventing the vertical dimension of the bumper beam 12 from being shrunk by the reinforcing rib 12f, the metal gusset 14 can be assembled to the bumper beam 12 without degrading its ability to be assembled in the U-shaped cross section. Not only can the vertical dimension of the gusset 14 be maximized to ensure a support effect of the collision load, but the inclined portion 13a of the bumper beam extension 13 is assembled to the inclined portion 18 of the bumper beam 12 with a rivet 37. Workability at the time of fastening is also improved.

  In addition, since the reinforcing rib 12f is positioned near the load input portion of the bumper beam 12, that is, in the vicinity of the first fixed portion 14a of the metal gusset 14, the compressive deformation near the load input portion is suppressed by the reinforcing rib 12f. Local destruction can be prevented.

  The plate thickness of the bumper beam extension 13 is set to a plate thickness that generates a load less than the proof strength of the front side frame 15 from the initial stage of the collision to the middle stage of the collision, and the front side frame 15 is bent and deformed in the late stage of the collision. Since the first thick plate portion 13c is provided on the inner side in the vehicle width direction so that the collision load input from the bumper beam 12 from the initial stage of the collision to the middle stage of the collision is applied only to the bumper beam extension 13 without bending the front side frame 15. The collision load is crushed and absorbed, and the collision load input from the bumper beam 12 in the latter half of the collision is caused by bending the front side frame 15 by applying a bending moment to the bumper beam extension 13 by the action of the second thick plate portion 13d. Because it absorbs collision energy While reducing the weight of the plate thickness of the bumper beam extension 13 with minimal, it is possible to increase the energy absorption amount.

  The bumper beam extension 13 is set such that the thickness of the first thick plate portion 13c on the inner side in the vehicle width direction and the second thick plate portion 13d on the outer side in the vehicle width direction are set larger than the plate thickness in the center in the vehicle width direction. The first thick plate portion 13c having a large length is connected to the front end of the front side frame 15 having a relatively high strength, and the second thick plate portion 13d having a small length in the front-rear direction is formed by the upper member 16 having a relatively low strength. Since it is connected to the front end (see FIG. 2), it is possible to transmit loads corresponding to the strength to the front side frame 15 and the upper member 16 to increase the amount of energy absorption while preventing deformation of the vehicle body at the time of a light collision. it can. In particular, since the second thick plate portion 13d is located on the outer side in the vehicle width direction than the front side frame 15 located on the inner side in the vehicle width direction, a bending moment is applied to the bumper beam extension 13 in the late stage of the collision. Can be easily folded.

  Further, only the first thick plate portion 13c exists at the front portion of the bumper beam extension 13, whereas both the first thick plate portion 13c and the second thick plate portion 13d exist at the rear portion of the bumper beam extension 13. The bumper beam extension 13 has a higher strength at the rear than at the front. As a result, the bumper beam extension 13 is sequentially crushed from the front to the rear in the initial and middle stages of the collision, and a large bending moment is applied to the front end of the front side frame 15 at the rear of the high-strength bumper beam extension 13 in the late stage of the collision. It is possible to increase the energy absorption amount by promoting the bending of the front side frame 15.

  Further, the radiator 40 of the engine and the condenser 41 of the air conditioner 41 are slidable in the front-rear direction at a position behind the bumper beam 12 and sandwiched between the pair of left and right metal gussets 14, 14 (see FIG. 1). ) When the radiator 40 and the condenser 41 are pushed back by the bumper beam 12 retreating due to the collision load, the crash stroke of the bumper beam 12 can be secured, and the space between the pair of left and right metal gussets 14 and 14 can be secured. The radiator 40 and the condenser 41 can be arranged by effectively utilizing the above, and the volume of the engine room can be expanded.

Second to fourth embodiments

  Although the cross-sectional shape of the metal gusset 14 of the first embodiment is an open cross section, the strength can be further increased by making it a closed cross section. The metal gusset 14 of the second embodiment shown in FIG. 13 (A) has a rectangular closed cross section, and the metal gusset 14 of the third embodiment shown in FIG. 13 (B) has a rectangular shape. The long side of the closed cross section has a reinforcing groove, and the metal gusset 14 of the fourth embodiment shown in FIG. 13C has a circular closed cross section. The first fixing portion 14a, the second fixing portion 14b, and the intermediate portion 14c of the metal gusset 14 may all have the same cross-sectional shape, or may have different cross-sectional shapes.

  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, although the front bumper 11 has been described in the embodiment, the present invention can also be applied to a rear bumper. In the case of the front bumper 11, the outer side in the front-rear direction corresponds to the front, and in the case of the rear bumper, the outer side in the front-rear direction corresponds to the rear.

  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, although the front bumper 11 has been described in the embodiment, the present invention can also be applied to a rear bumper. In the case of the front bumper 11, the outer side in the front-rear direction corresponds to the front, and in the case of the rear bumper, the outer side in the front-rear direction corresponds to the rear.

12 Bumper beam 12a Bottom wall 12b Upper wall 12c Lower wall 12e Extension part 13 Bumper beam extension 13a Inclined part 18 Inclined part 19 Continuous fiber reinforced resin layer 20 Discontinuous fiber reinforced resin layer

Claims (1)

A bumper beam (12) made of fiber reinforced resin arranged in the vehicle width direction and a pair of left and right fiber reinforced resin bumper beam extensions arranged in the front-rear direction and supporting both ends of the bumper beam (12) in the vehicle width direction (13) an automobile bumper comprising:
Before Symbol bumper beam (12), a bottom wall (12a), the upper wall (12b) and the lower wall is formed in a U-shaped cross section which opens in the longitudinal direction inside a (12c), both vehicle transverse direction end The bumper beam (12) has a two-layer structure in which a continuous fiber reinforced resin layer (19) and a discontinuous fiber reinforced resin layer (20) are laminated. The continuous fiber reinforced resin layer (19) includes continuous fibers oriented over the entire vehicle width direction and continuous fibers oriented in a direction perpendicular to the vehicle width direction, and the discontinuous fiber reinforcement The resin layer (20) surrounds the end of the continuous fiber reinforced resin layer (19) while extending the front and rear inner ends of the upper wall (12b) and the lower wall (12c) outwardly in the front and rear direction (12e). )
The bumper beam extension (13) formed in a hollow closed cross section is fitted to the inclined portion (18) of the bumper beam (12) from the rear and fixed to the outer end in the front-rear direction, and the bottom wall (12a). A bumper for an automobile, comprising an inclined portion (13a) inclined along the line .

Images