JP2018144630A - Bumper beam for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bumper beam for vehicle capable of efficiently transmitting a collision load toward inside in a longitudinal direction of the vehicle.SOLUTION: A bumper beam 10 for vehicle includes: a bumper beam body 11 which has a flat part 12a and an inclined part 12 and is formed of a continuous fiber-reinforced resin; a discontinuous fiber part 13 which is formed on the bumper beam body 11 and is formed of a discontinuous fiber-reinforced resin; and a vehicle body fitting part 14 which is formed inside in a longitudinal direction of the vehicle of the inclined part 12b and mounts the bumper beam body 11 on the vehicle body, where the discontinuous fiber part 13 includes an outersurface deformation suppression part 15 extending from the vehicle body fitting part 14 through the inclined part 12b to the flat part 12a.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a bumper beam for a vehicle.

Conventionally, a vehicular bumper beam made of fiber reinforced resin that extends in the vehicle body width direction before and after the vehicle body is known (see, for example, Patent Document 1). The bumper beam is formed of a fiber reinforced resin including continuous fibers oriented in the vehicle body width direction.
Such a bumper beam is made of the above-described fiber-oriented resin, so that the bumper beam itself has excellent collision energy absorption performance.

Japanese Patent Laid-Open No. 2017-1422

  However, in the conventional bumper beam (see, for example, Patent Document 1), when collision energy is input, the outer surface of the bumper beam in the front-rear direction of the vehicle body is flat toward the center from both outer sides in the vehicle body width direction. A compressive force occurs. The bumper beam may be deformed out of plane by this compressive force. When the bumper beam undergoes out-of-plane deformation at the time of a collision, the transmission load to the vehicle body side joined to the bumper beam decreases.

  The subject of this invention is providing the bumper beam for vehicles which can transmit a collision load efficiently toward the inner side of the vehicle body front-back direction.

  A bumper beam for a vehicle that solves the above problems includes a flat portion that extends in the vehicle body width direction and has a flat outer side in the vehicle body front-rear direction, and a pair of inclined portions that are formed on both outer sides of the flat portion in the vehicle body width direction. A bumper beam body formed of continuous fiber reinforced resin; a discontinuous fiber portion made of discontinuous fiber reinforced resin formed on the bumper beam body; and an inner side of the inclined portion in the vehicle body front-rear direction. And a discontinuous fiber portion including an out-of-plane deformation suppressing portion extending from the vehicle body attachment portion to the flat portion through the inclined portion.

  ADVANTAGE OF THE INVENTION According to this invention, the bumper beam for vehicles which can transmit a collision load efficiently toward the inner side of the vehicle body front-back direction can be provided.

1 is an overall perspective view of a vehicle bumper beam according to an embodiment of the present invention. FIG. 2 is a partially enlarged top view of a left half of the vehicle bumper beam of FIG. 1. It is composition explanatory drawing of the fiber reinforced resin which forms the bumper beam for vehicles which concerns on embodiment of this invention, (a) is structure explanatory drawing of the fiber reinforced resin containing a continuous fiber, (b) is the fiber reinforced resin containing a discontinuous fiber. It is composition explanatory drawing of resin. (A) is a top view of a vehicle bumper beam, (b) is a diagram of a bending moment generated at a position corresponding to the vehicle bumper beam shown in (a). (C) is the diagram of the bending moment in the bumper beam which does not have an out-of-plane deformation | transformation suppression part shown as a comparative example. FIG. 9 is a partially enlarged top view of a left half of a vehicle bumper beam according to a modified example, corresponding to FIG. 2.

  Next, the vehicle bumper beam according to the embodiment (the present embodiment) of the present invention will be described in detail. The vehicular bumper beam of the present invention (hereinafter simply referred to as “bumper beam”) includes both a front bumper beam and a rear bumper beam. In the following embodiment, a rear bumper beam will be described as an example.

FIG. 1 is an overall perspective view of a bumper beam 10 according to the present embodiment.
In the following description, the front / rear / left / right / up / down directions (see FIG. 1 and the like) are based on the front / rear, right / left, up / down directions of the driver seated on the vehicle. The left and right directions shown in FIG. 1 coincide with the vehicle body width direction. Further, in the vehicle body width direction or the vehicle body front-rear direction, the inner side or the outer side is defined as an inner side on the center portion side of the vehicle body in a top view and an outer side on the opposite side.

  The bumper beam body 11 is made of fiber reinforced resin. As the fiber reinforced resin in the present embodiment, thermoplastic CFRP (CFRP: Carbon Fiber Reinforced Plastics) is assumed. This thermoplastic CFRP is configured by including carbon fibers in a thermoplastic resin as a matrix. This thermoplastic CFRP will be described in detail later.

  As shown in FIG. 1, a bumper beam 10 includes a bumper beam main body 11 formed of continuous fiber reinforced resin, a discontinuous fiber portion 13 formed of discontinuous fiber reinforced resin, and a rear side frame 21 using the bumper beam main body 11 as a vehicle body. And a vehicle body attachment portion 14 attached to the vehicle body. In FIG. 1, the rear side frame 21 is indicated by a virtual line (two-dot chain line).

≪Bumper beam body≫
As shown in FIG. 1, the bumper beam main body 11 is a member that is disposed on the rear side of the vehicle body and extends in the vehicle body width direction.
The bumper beam main body 11 includes a vertical wall 11a disposed on the rear side of the vehicle body, an upper wall 11b extending from the upper end of the vertical wall 11a toward the front side, and a lower end of the vertical wall 11a in a cross-sectional view intersecting the extending direction. And a lower wall 11c extending toward the front side. That is, the bumper beam main body 11 is formed in a substantially U shape whose rear side is closed by the vertical wall 11a and whose front side is opened between the upper wall 11b and the lower wall 11c.

  The bumper beam main body 11 includes a flat portion 12a having a flat rear surface extending at a center portion in the vehicle body width direction, and a pair of inclined portions 12b extending further outward in the vehicle body width direction from both ends of the flat portion 12a. Yes.

FIG. 2 is a partially enlarged top view of the left half of the bumper beam 10 of FIG.
As shown in FIG. 2, the flat part 12a forms a substantially straight part of the bumper beam body 11 in the vehicle body width direction.
The inclined portion 12b is gradually displaced toward the rear side as it extends outward from the end of the flat portion 12a in the vehicle body width direction. Thereby, as shown in FIG. 1, the bumper beam main body 11 has a substantially bow-like shape convex backward.

≪Discontinuous fiber part≫
As shown in FIG. 1, the discontinuous fiber portion 13 mainly includes an out-of-plane deformation suppressing portion 15, a protruding portion 16, and an outer protruding portion 17. The fiber reinforced resin including the discontinuous fibers forming the discontinuous fiber portion 13 will be described in detail later.

<Out-of-plane deformation suppression part>
As shown in FIG. 1, the out-of-plane deformation suppressing portion 15 is formed by ribs standing on the upper surface and the lower surface of the bumper beam body 11. The out-of-plane deformation suppressing portion 15 has the same structure on each of the upper and lower surfaces of the bumper beam main body 11. Therefore, only the out-of-plane deformation suppressing portion 15 on the upper surface of the bumper beam main body 11 will be described below, and the description of the out-of-plane deformation suppressing portion 15 on the lower surface will be omitted.

  As shown in FIG. 1, the out-of-plane deformation suppressing portion 15 in the present embodiment extends from the inner side in the vehicle body width direction of the vehicle body attachment portion 14 to be described later to the flat portion 12 a via the inclined portion 12 b. The out-of-plane deformation suppressing portion 15 includes an inclined extending portion 18, an outer extending portion 19, and an inner extending portion 20.

  The inclined extending portion 18 extends obliquely across the inclined portion 12b from the inner side in the vehicle body width direction of the vehicle body mounting portion 14 to be described later, and extends to the boundary between the inclined portion 12b and the flat portion 12a at the rear end edge of the bumper beam body 11. Yes.

  The outer extending portion 19 extends along the rear end edge of the flat portion 12 a of the bumper beam main body 11. The outer extending portion 19 is connected to the inclined extending portion 18 at the boundary between the inclined portion 12b and the flat portion 12a.

  The inner extending portion 20 extends along the front edge of the bumper beam main body 11 and extends along the outer edge in the vehicle body width direction on the upper surface of the outer protrusion 17 described later.

<Projection>
As shown in FIG. 1, the protruding portion 16 is formed so as to protrude from the outer end portion of the bumper beam body 11 in the vehicle body width direction toward the outside in the vehicle body front-rear direction (backward in FIG. 1).
The protrusion 16 in the present embodiment is formed of a substantially rectangular tube that is vertically long in the vertical direction. This substantially rectangular cylinder opens to the outside in the longitudinal direction of the vehicle body and closes to the bumper beam main body 11 side.

FIG. 2 is a partially enlarged top view of the left half of the bumper beam 10 of FIG.
As shown in FIG. 2, the protrusion 16 has an isosceles trapezoidal shape with an end edge on the inner side (front side in FIG. 2) in the vehicle longitudinal direction of the vehicle body attachment portion 14 to be described later as viewed from above. Further, the protruding portion 16 protrudes to a virtual extension line L to the outside in the vehicle body width direction of the outer extending portion 19 of the bumper beam main body 11. That is, the tip of the protrusion 16 is located on the virtual extension line L.
In FIG. 2, the left protrusion 16 is not illustrated, but the left protrusion 16 is configured in the same manner as the right protrusion 16.

<Outside protrusion>
As shown in FIG. 1, the outer protrusion 17 is formed so as to protrude from the outer end of the bumper beam main body 11 in the vehicle width direction toward the outer side of the bumper beam main body 11 in the vehicle width direction. . Specifically, the outer protrusion 17 in the present embodiment protrudes obliquely rearward so as to be separated from the protrusion 16 on the outer side of the protrusion 16 in the vehicle width direction.
The outer protrusion 17 in the present embodiment is formed of a vertically long substantially rectangular tube. This substantially rectangular cylinder opens to the outside in the longitudinal direction of the vehicle body and closes to the bumper beam main body 11 side.

As shown in FIG. 2, the outer projecting portion 17 has an isosceles trapezoidal shape with a connection line with the bumper beam main body 11 as a bottom side in a top view. Further, when both oblique sides of the isosceles trapezoid are extended toward the front side, they substantially intersect with both end points of the inner edge of the vehicle body mounting portion 14 described later in the vehicle longitudinal direction (front side in FIG. 2). .
And the front-end | tip of the outer side protrusion part 17 is set so that it may be located inside the vehicle body front-back direction (front side of FIG. 2) rather than the front-end | tip of the protrusion part 16. FIG.

  Incidentally, the base end portion of the protrusion 16 and the base end portion of the outer protrusion 17 defined by the joint surface with the bumper beam body 11 are the end portion 21a of the rear side frame 21 to which the bumper beam body 11 is joined and the vehicle body longitudinal direction. It is arranged to overlap.

≪Body attachment part≫
As shown in FIG. 2, the vehicle body attachment portion 14 in the present embodiment is an outer end portion of the bumper beam body 11 in the vehicle body width direction, and is set to the innermost end surface (front side in FIG. 2) in the vehicle body front-rear direction. ing. The bumper beam 10 is joined to the end portion 21 a of the rear side frame 21 through the vehicle body attachment portion 14. In addition, this invention is not limited to what the bumper beam 10 is directly attached to the rear side frame 21, For example, it can also be set as the structure attached to the vehicle body side via other attachment members, such as a beam extension.

≪Fiber reinforced resin≫
FIG. 3A is a configuration explanatory diagram of a fiber reinforced resin including continuous fibers, and FIG. 3B is a configuration explanatory diagram of a fiber reinforced resin including discontinuous fibers.
As described above, the bumper beam main body 11 is formed of a fiber reinforced resin including continuous fibers, and includes an out-of-plane deformation suppressing portion 15 (an inclined extending portion 18, an outer extending portion 19, and an inner extending portion 20), and a protrusion. The part 16 and the outer protrusion part 17 are formed of a fiber reinforced resin including continuous fibers.

  As shown in FIG. 3A, the fiber reinforced resin (continuous fiber reinforced resin) containing continuous fibers in this embodiment is a carbon fiber made of long fibers in the thermoplastic resin R as a matrix as described above. C1 is included. Specifically, the carbon fibers C1 made of long fibers are arranged so as to intersect at 90 degrees so as to form a mesh. The fiber reinforced resin containing such continuous fibers can be formed by, for example, laminating while shifting the phase of the UD material by 90 degrees. Further, the phase of the UD material is not limited to 90 degrees, and can be changed in increments of 45 degrees such as 0 degrees, 45 degrees, 90 degrees, and 135 degrees.

Examples of the thermoplastic resin include polyolefin resins such as polypropylene (PP) and polyethylene (PE), polyester resins such as polyethylene terephthalate (PET), polycarbonate resins such as polycarbonate (PC), and polystyrenes such as polystyrene (PS). Resins, polyvinyl chloride resins such as polyvinyl chloride (PVC), polyamide resins such as nylon 6 and nylon, polyvinyl alcohol (PVA), polyacrylonitrile (PAN), polyvinylidene fluoride (PVDF), polyethersulfone (PES) ), Polyethylene oxide (PEO) and the like. Of these, a polyamide-based resin is preferable, but not limited thereto.
There is no restriction | limiting in particular as carbon fiber, For example, a PAN type thing can be used conveniently.

  As shown in FIG. 3B, the fiber reinforced resin containing discontinuous fibers (discontinuous fiber reinforced resin) in the present embodiment contains carbon fibers C2 made of short fibers in the thermoplastic resin R as a matrix. It is a waste. Examples of the short fibers include, but are not limited to, those having a length of about 50 mm. In the fiber reinforced resin containing discontinuous fibers, the orientation of the carbon fibers C2 made of short fibers is random.

  The bumper beam 10 made of the fiber reinforced resin as described above can be obtained by two-color molding of a fiber reinforced resin containing continuous fibers and a fiber reinforced resin containing discontinuous fibers. Specifically, the bumper beam main body 11 formed of a fiber reinforced resin containing continuous fibers is preliminarily molded in a predetermined preliminary mold, and the primary molded product is placed in the main mold. Next, the bumper beam 10 can be obtained by injecting a molten fiber-reinforced resin material containing discontinuous fibers into the mold.

<Effect>
Next, functions and effects achieved by the bumper beam 10 according to the present embodiment will be described.
The bumper beam 10 according to the present embodiment includes an inclined extending portion 18 made of a rib as the out-of-plane deformation suppressing portion 15. The inclined extending portion 18 extends obliquely across the inclined portion 12b from the inner side in the vehicle body width direction to the boundary between the inclined portion 12b and the flat portion 12a at the rear end edge of the bumper beam main body 11.

  The bumper beam 10 having such an inclined extending portion 18 can efficiently absorb the collision load input to the bumper beam main body 11 by providing the inclined extending portion 18 on the inclined portion 12b. Thereby, the out-of-plane deformation of the bumper beam 10 at the time of the collision can be effectively suppressed, and the collision load can be efficiently transmitted toward the inner side in the longitudinal direction of the vehicle body.

Further, the bumper beam 10 according to the present embodiment further includes an outer extending portion 19 made of a rib as the out-of-plane deformation suppressing portion 15 and an inner extending portion 20.
According to such a bumper beam 10, the outer extending portion 19 and the inner extending portion 20 cooperate with the inclined extending portion 18 to further effectively suppress the out-of-plane deformation of the bumper beam 10. it can.

  4A is a top view of the bumper beam 10, and FIG. 4B is a diagram showing a bending moment generated at a position corresponding to the bumper beam 10 shown in FIG. 4A. (C) is the diagram of the bending moment in the bumper beam which does not have the out-of-plane deformation | transformation suppression part 15 shown as a comparative example.

  Referring to the diagram of the bending moment in the bumper beam that does not have the out-of-plane deformation suppressing portion 15 shown in FIG. 4C, when a collision load is input, in the length region defined in the vehicle width direction of the bumper beam, bending is performed. The moment appears as a positive value.

On the other hand, as shown in FIG. 4B, in the diagram of the bumper beam 10 of the present embodiment having the out-of-plane deformation suppressing portion 15 (see FIG. 4A), the object Ob (see FIG. 4A). ) Collides with the bumper beam 10 (see FIG. 4A), a negative bending moment appears outside the bumper beam 10 in the vehicle width direction.
Specifically, the diagram of the present embodiment illustrated in FIG. 4B is shifted downward from the diagram illustrated in FIG. 4C so as to cross the bending moment “0” line.
According to such a bumper beam 10 of the present embodiment, the magnitude of the bending moment that appears as a positive value is reduced, and a part of the positive bending moment is canceled by the negative bending moment. Thereby, the bumper beam 10 of this embodiment can suppress the out-of-plane deformation of the bumper beam 10 effectively.

Further, the bumper beam 10 according to the present embodiment has a protruding portion 16 at the outer end of the bumper beam main body 11 in the vehicle body width direction.
According to such a bumper beam 10, when an object that reaches the end of the bumper beam 10 in the vehicle width direction collides with the bumper beam 10, the protrusion 16 shares the collision load from the object. That is, according to the bumper beam 10, the collision load can be dispersed in the vehicle width direction of the bumper beam 10.

Further, the bumper beam 10 according to the present embodiment includes an outer protrusion 17 on the outer side of the protrusion 16 in the vehicle width direction.
According to such a bumper beam 10, the load at the time of an oblique collision with the vehicle body can also be absorbed by the outer protruding portion 17. In addition, since the tip of the outer protrusion 17 is located on the inner side in the vehicle longitudinal direction than the tip of the protrusion 16, the outer protrusion 17 may become an obstacle when the object collides flat with the bumper beam 10. can avoid.

Further, in the bumper beam 10 according to the present embodiment, the proximal end portion of the protruding portion 16 and the proximal end portion of the outer protruding portion 17 are in the longitudinal direction of the vehicle body and the end portion 21a of the rear side frame 21 to which the bumper beam main body 11 is joined. They are arranged so as to overlap.
According to such a bumper beam 10, the collision load can be efficiently transmitted to the rear side frame 21 when a collision load is input to at least one of the protrusion 16 and the outer protrusion 17.

As mentioned above, although embodiment of this invention was described, this invention is not limited to the said embodiment, It can implement with a various form.
In the above-described embodiment, as shown in FIG. 2, the outer end surface of the protrusion 16 in the front-rear direction of the vehicle body is flat according to the outer edge of the flat portion 12 a of the bumper beam body 11 in the front-rear direction of the vehicle body. .

FIG. 5 is a partially enlarged top view of the left half of the bumper beam 10 according to a modification, and corresponds to FIG.
As shown in FIG. 5, the bumper beam 10 according to the modified example has an inclined surface 16 a that is displaced toward the inner side in the longitudinal direction of the vehicle body toward the outer side in the vehicle body width direction at the tip of the protruding portion 16. .
According to the bumper beam 10 according to this modification, the tip of the protruding portion 16 is sharp, so that the trigger of the protruding portion 16 at the time of collision can be created. That is, according to the bumper beam 10, it is possible to more reliably absorb the collision energy due to the crushing of the protruding portion 16.

Further, in the above-described embodiment, the bumper beam 10 in which the ribs as the out-of-plane deformation suppressing portions 15 are provided on the upper and lower surfaces of the bumper beam body 11 has been described. It can also be set as the structure which provided the out-of-plane deformation | transformation suppression part 15. FIG.
In the above embodiment, the out-of-plane deformation suppressing portion 15 has all of the inclined extending portion 18, the outer extending portion 19, and the inner extending portion 20. Only the inclined extending portion 18 that is a rib connecting the mounting portion 14 may be configured as the out-of-plane deformation suppressing portion 15.

  Moreover, although the said embodiment demonstrated the bumper beam 10 in which the one outer side protrusion part 17 was located in a line with respect to the one protrusion part 16, this invention can also be set as the structure in which the outer side protrusion part 17 is arranged in multiple numbers.

  In the above embodiment, the example in which the present invention is applied to the rear bumper beam has been described. However, the present invention can also be applied to a front bumper beam.

DESCRIPTION OF SYMBOLS 10 Bumper beam 11 Bumper beam main body 12a Flat part 12b Inclination part 13 Discontinuous fiber part 14 Car body attachment part 15 Out-of-plane deformation suppression part 16 Protrusion part 17 Outer protrusion part 18 Inclined extension part 19 Outer extension part 20 Inner extension part 21 Rear side Frame L Virtual extension

Claims (6)

A bumper beam formed of a continuous fiber reinforced resin, which has a flat portion extending in the vehicle body width direction and having a flat outer portion in the vehicle body front-rear direction and a pair of inclined portions respectively formed on both outer sides of the flat portion in the vehicle body width direction. The body,
A discontinuous fiber portion made of discontinuous fiber reinforced resin formed in the bumper beam body;
A vehicle body mounting portion that is formed inside the vehicle body in the longitudinal direction of the inclined portion, and that attaches the bumper beam body to the vehicle body,
The bumper beam for vehicles, wherein the discontinuous fiber portion includes an out-of-plane deformation suppressing portion that extends from the vehicle body attachment portion to the flat portion through the inclined portion.   The out-of-plane deformation suppressing portion includes an outer extending portion extending along the vehicle body width direction at an outer edge in the vehicle body front-rear direction in the flat portion of the bumper beam body, and a vehicle body width at least at an inner edge in the vehicle body front-rear direction of the bumper beam body. The vehicular bumper beam according to claim 1, further comprising an inner extending portion extending along the direction. The discontinuous fiber portion has a protruding portion that protrudes from the outer end portion in the vehicle body width direction of the bumper beam body toward the outside in the vehicle body front-rear direction,
The said protrusion part protrudes until it reaches the virtual extension line extended toward the outer side of the vehicle body width direction of the outer edge of the vehicle body front-back direction in the said flat part, The Claim 1 or Claim 2 characterized by the above-mentioned. Bumper beam for vehicles.   4. The vehicle bumper beam according to claim 3, wherein a tip end of the projecting portion is inclined so as to be displaced toward an inner side in a longitudinal direction of the vehicle body toward an outer side in the vehicle body width direction when viewed from above. The discontinuous fiber portion has an outer protruding portion that protrudes from the outer end portion of the bumper beam main body in the vehicle width direction toward the outer side of the protruding portion than the protruding portion,
5. The vehicular bumper beam according to claim 3, wherein a front end of the outer protrusion is located on an inner side in a vehicle front-rear direction than a front end of the protrusion.   The base end portion of the projecting portion and the base end portion of the outer projecting portion are disposed so as to overlap with an end portion of a side frame to which the bumper beam main body is joined in the longitudinal direction of the vehicle body. The bumper beam for vehicles as described in 5.

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