JP2008110690A - Reinforcing member made of fiber reinforced plastic - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lightweight and highly rigid reinforcing member. <P>SOLUTION: The reinforcing member made of a fiber reinforced plastic reinforces tunnels of a platform for an automobile. The reinforcing member is curved in the longitudinal direction of a vehicle body, and extends in the vehicle width direction, and has a hollow structure. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a lower stiffening structure for an automobile platform.

Conventionally, there are the following structures as the substructure of an automobile platform. A tunnel portion is provided in the vehicle width direction center of the platform so as to project in the vehicle interior direction and extend in the vehicle front-rear direction. For the purpose of maintaining a predetermined cross-sectional shape of the tunnel portion, a stiffening member (described as a tunnel member in Patent Document 1 and an undercross member in Patent Document 2) is installed at the lower end portion of the tunnel portion. (For example, Patent Documents 1 and 2). Furthermore, although not described in this patent document, generally metal stiffening members are used.
JP-A-4-349080 JP 2004-338581 A

  In an automatic vehicle or the like, there are cases where other parts interfere and the stiffening member cannot be installed linearly in the vehicle width direction as in the patent document. In this case, it is necessary to take a bent shape, but it is difficult to ensure sufficient rigidity with the same weight with a metal stiffening member as compared with a linearly constructed member.

  The present invention is intended to provide a lightweight and highly rigid stiffening member in view of the background as in the prior art.

  In order to solve the above problems, the present inventors made the stiffening member made of fiber reinforced plastic and made a hollow structure. As a result, a stiffening member having a light weight and sufficient rigidity could be obtained. Means for solving this problem is based on the matters described in the following items.

  (1) A member for stiffening between tunnels of an automobile platform, wherein the stiffening member is curved in the vehicle longitudinal direction and extends in the vehicle width direction and has a hollow structure. A fiber-reinforced plastic stiffening member.

  (2) The fiber-reinforced plastic stiffening member according to (1), wherein a weight ratio of the reinforcing fibers along the vehicle body width direction is 40% to 80% among the reinforcing fibers constituting the stiffening member.

  (3) The fiber reinforced plastic auxiliary material according to (1) or (2), wherein the hollow structure of the stiffening member is formed by mechanically joining at least two fiber reinforced plastic members. Rigid member.

  (4) The fiber-reinforced plastic stiffening member according to (1) or (2), wherein the hollow structure of the stiffening member is formed by bonding at least two fiber-reinforced plastic members.

  (5) 50% or more of the weight ratio of the reinforcing fibers constituting the fiber-reinforced plastic stiffening member is within a range of elastic modulus of 200 to 700 GPa and a fiber volume content (Vf) of 40 to 70%. The fiber-reinforced plastic stiffening member according to any one of (1) to (4), which is within a range.

  (6) The fiber reinforcement according to any one of (1) to (5) above, wherein the reinforcing fiber constituting the fiber-reinforced plastic stiffening member is a unidirectionally aligned form or a woven fabric that is a continuous fiber. Plastic stiffening member.

  ADVANTAGE OF THE INVENTION According to this invention, the stiffening member which has light weight and sufficient rigidity can be provided as a member which stiffens between the tunnels of a vehicle platform.

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

  The fiber-reinforced plastic stiffening member of the present invention is made of a composite material containing reinforcing fibers and a resin.

  As the reinforcing fiber to be constituted, materials used as ordinary reinforcing fibers such as carbon fiber, glass fiber, aramid fiber, boron fiber, etc. can be used, and they can also be used in combination. Among these, carbon fibers that can maximize the weight reduction effect are preferable. Such carbon fibers include pitch-based and PAN-based carbon fibers and graphitic carbon, and among them, PAN-based carbon fibers having excellent strength and elastic modulus are preferable. The tensile modulus of carbon fiber is preferably in the range of 200 GPa to 700 GPa, more preferably in the range of 200 GPa to 500 GPa, and particularly preferably in the range of 250 GPa to 350 GPa. As a form of the reinforcing fiber base, a unidirectionally aligned form of continuous fibers, a woven form, a dispersive form of discontinuous form, and the like can be used. Thermosetting resins such as epoxy resins, unsaturated polyester resins, phenolic resins, and vinyl ester resins can be used as the resins that make up fiber reinforced plastics, but they have excellent mechanical properties and high adhesion to carbon fibers. Is preferred.

  Further, 50% or more of the weight ratio of the reinforcing fibers (particularly carbon fibers) constituting the fiber reinforced plastic stiffening member is in the range of the elastic modulus 200 GPa to 700 GPa, and the fiber volume content (Vf) is 40 to 70. % Is preferably in the range of%.

  Thus, by designing a high elastic modulus, a lighter and more rigid stiffening member can be obtained. In addition, if the reinforcing fiber with a weight ratio of 50% or more constituting the reinforcing fiber plastic stiffening member is a unidirectional drawing form or woven cloth that is a continuous fiber, even if it is hollow, the penetration impact resistance is improved. It is preferable.

  1 and 2 show a fiber-reinforced plastic stiffening member according to an embodiment of the present invention.

  The fiber-reinforced plastic stiffening member according to the present invention shown in FIGS. 1 and 2 is a member that is curved forward in the vehicle longitudinal direction and extends in the vehicle width direction and has a hollow structure. By curving in the longitudinal direction of the car body, it is possible to avoid interference with other parts at the lower part of the car body, and by making it hollow, the cross-sectional rigidity can be improved efficiently, resulting in a lightweight and highly rigid structure. In addition, not only can deformation in the opening direction (outside in the vehicle width direction) and shear deformation (in the vehicle longitudinal direction) at the lower end of the tunnel part be restricted, but also bending deformation (in the vehicle vertical direction) can be regulated. . In addition, since it is made of fiber reinforced plastic, it has good moldability even when it has a complicated shape, and can be reduced in weight.

  Among the reinforcing fibers constituting the stiffening member, the weight ratio of the reinforcing fibers along the vehicle body width direction is preferably in the range of 40% to 80%, and in the range of 40% to 60%. Is more preferable, and it is particularly preferable to be within the range of 40% to 50%. If the proportion of the reinforcing fibers along the vehicle body width direction is less than 40%, sufficient rigidity cannot be obtained. Conversely, if it exceeds 80%, the structure may become unstable. The proportion occupied by is preferably in the range of 40% to 80%.

  Here, the direction along the vehicle body width direction is not limited to the direction perpendicular to the vehicle body traveling direction, but may be a direction along the curved shape of the stiffening member. In addition, the hollow structure of the stiffening member may be integrally molded, or may be composed of at least two parts, and the two parts may be mechanically joined with bolts or the like. It may be chemically bonded.

  The molding method of the stiffening member comprising the embodiment according to the present invention described above is not particularly limited, such as Resin transfer molding molding method, crimp molding method, press molding method, autoclave molding method, but from the viewpoint of strength and rigidity. It is preferable to use a press molding method using prepreg or an autoclave molding method. This is because the use of the prepreg makes it possible to achieve lighter weight and higher rigidity. From the viewpoint of heat resistance, it is preferable to use a prepreg.

It is a perspective view which shows an example of the fiber reinforced plastic stiffening member of this invention. It is a bottom view of FIG. FIG. 3 is a cross-sectional view taken along line AA in FIG. 2.

Explanation of symbols

1 Platform 2 Frame 3 Fiber-reinforced plastic stiffener

Claims (6)

  A member for stiffening between tunnels of an automobile platform, wherein the stiffening member is curved in the longitudinal direction of the vehicle body, extends in the vehicle width direction, and has a hollow structure. A fiber-reinforced plastic stiffening member.   2. The fiber-reinforced plastic stiffening member according to claim 1, wherein, among the reinforcing fibers constituting the stiffening member, a weight ratio of the reinforcing fibers along the vehicle body width direction is 40% to 80%.   The fiber-reinforced plastic stiffening member according to claim 1 or 2, wherein the hollow structure of the stiffening member is formed by mechanically joining at least two fiber-reinforced plastic members.   The fiber-reinforced plastic stiffening member according to claim 1 or 2, wherein the hollow structure of the stiffening member is formed by bonding at least two fiber-reinforced plastic members.   50% or more of the weight ratio of the reinforcing fibers constituting the fiber reinforced plastic stiffening member is within a range of elastic modulus of 200 to 700 GPa and a fiber volume content (Vf) of 40 to 70%. The fiber-reinforced plastic stiffening member according to any one of claims 1 to 4.   The fiber-reinforced plastic stiffening member according to any one of claims 1 to 5, wherein a form of the reinforcing fiber constituting the fiber-reinforced plastic stiffening member is a one-way alignment form or a woven fabric which is a continuous fiber. .

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