JP2014218179A - Energy absorption member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an energy absorption member that uses a reinforcement member, which achieves high energy absorption performance and is made of a fiber-reinforced resin, and thereby develops excellent energy absorption performance as the whole member even if a flexural load etc. is applied.SOLUTION: In a structure member for a vehicle, a reinforcement member 5 made of a fiber-reinforced resin is disposed in a hollow region 4 formed by a metal outer panel 2 and a metal inner panel 3. The reinforcement member 5 has a hollow closed cross section shape and is fixedly joined to at least the inner panel 3.

Description

  The present invention relates to an energy absorbing member as a structural member for an automobile.

  From the viewpoint of collision safety, automobile structural members are required to have high energy absorption performance as well as higher strength of the members. As a structure of a conventional general automobile structural member, for example, a structure as shown in FIG. In the structure of the automotive structural member 100 shown in FIG. 6, a metal reinforcing member 103 is disposed in a hollow region formed by the metal outer panel 101 and the metal inner panel 102.

  However, in the automobile structural member 100 reinforced with the metal reinforcing member 103 as described above, if a large bending load is applied to the member at the time of a collision, the metal material yields and cannot bear the load, and the load decreases. Happens. Furthermore, as will be described later, the member may be deformed in cross section, the cross section may be reduced, and the load may be further reduced.

  In order to cope with such a problem in metal structural members for automobiles, a technique using a member made of fiber reinforced resin, which is generally said to have high energy absorption performance, as at least a part of the structural member is known. It has been.

  For example, Patent Document 1 discloses a vehicle skeleton structure in which an uneven (corrugated) fiber reinforced resin reinforcing member is attached to an outer panel of an automobile structural member. Patent Document 2 discloses an automobile impact absorbing member made of a fiber reinforced resin having a laminated sheet-like fiber reinforcing material having a square cross section. Further, Patent Document 3 discloses a center pillar structure of an automobile in which a metal reinforcement similar to that is disposed on the inner surface of a fiber-reinforced resin outer panel having a substantially hat-shaped cross section.

JP 2010-195352 A Japanese Patent No. 4118263 Japanese Patent No. 4093107

  However, in the structure described in Patent Document 1, since the added fiber-reinforced resin reinforcing member is formed in a corrugated shape, for example, the reinforcing member has high energy absorption performance in the axial direction (longitudinal direction). Therefore, it is not possible to expect excellent energy absorption performance as a whole member against bending load applied to the skeletal structure member. In addition, the structures described in Patent Documents 2 and 3 cannot be applied when a metal outer panel structure is required because the outer panel itself is made of fiber reinforced resin.

  Accordingly, an object of the present invention is to use a reinforcing member made of fiber reinforced resin having high energy absorption performance in a structural member for an automobile that requires a configuration of a metal outer panel and a metal inner panel, bending load, etc. An object of the present invention is to provide an energy absorbing member capable of exhibiting excellent energy absorbing performance as a whole member even when the pressure is applied.

  In order to solve the above-mentioned problems, an energy absorbing member according to the present invention is an automotive structure in which a reinforcing member made of fiber reinforced resin is arranged in a hollow region formed by a metal outer panel and a metal inner panel. The reinforcing member has a hollow closed cross-sectional shape and is joined and fixed to at least the inner panel.

  In such an energy absorbing member according to the present invention, the metal outer surface forming structure of the member is ensured by the outer panel and the inner panel, and the hollow region formed by the outer panel and the inner panel is made of fiber reinforced resin. By arranging the reinforcing member, the reinforcing member can exhibit high energy absorption performance of the fiber reinforced resin. This fiber reinforced resin reinforcing member has a hollow closed cross-sectional shape, so that the member itself has high rigidity, can exhibit excellent reinforcing performance, and is bonded and fixed at least to the inner panel. As a result, when a bending load is applied, the progress of the fracture in the cross-section direction is suppressed, the cross-section deformation can be suppressed, and a decrease in load that can be handled is suppressed. In addition, at the fracture portion of the fiber reinforced resin reinforcing member when a bending load is applied, it is as if both sides of the fracture portion are in a butted state, and the bending mode shifts to the axial compression mode at the fracture portion, as described later. As a result, the load-stroke (displacement) characteristic becomes substantially constant, and the sequential fracture characteristic is manifested, and the excellent energy absorption performance is manifested. As a result, the specific fiber-reinforced resin reinforcing member disposed in the hollow region provides the desired reinforcing performance of the automotive structural member and exhibits excellent energy absorption performance.

  In the energy absorbing member according to the present invention, the reinforcing member is preferably disposed so as to contact the outer panel. In this way, the reinforcing member is sandwiched between the inner panel and the outer panel. For example, after the bending load reaches the breaking load of the reinforcing member, the breaking in the cross-sectional direction does not proceed, and the cross-sectional deformation is further suppressed. As a result, it is possible to further suppress the load drop and to exhibit the excellent energy absorption performance as described above more reliably.

  It is also preferable that the reinforcing member is bonded and fixed to the outer panel. If it does in this way, it will become possible to control cross-sectional deformation of a reinforcing member more certainly, while being able to control load fall further and to express the above-mentioned outstanding energy absorption performance more certainly.

  As a more specific form of such an energy absorbing member according to the present invention, for example, the outer panel, the inner panel, and the reinforcing member extend in the longitudinal direction of the structural member for automobile, and the transverse of the reinforcing member The form in which the surface has the said hollow closed cross-sectional shape is mentioned.

  The reinforcing fiber used in the fiber reinforced resin constituting the reinforcing member in the energy absorbing member according to the present invention is not particularly limited, and carbon fiber, glass fiber, aramid fiber, etc. Although it can be used, it is preferable that carbon fiber is included from the viewpoints of high mechanical properties and ease of strength design.

  The matrix resin of the fiber reinforced resin applicable to the present invention may be a thermosetting resin or a thermoplastic resin. In the case of a thermosetting resin, examples of the main material include an epoxy resin, an unsaturated polyester resin, a vinyl ester resin, a phenol resin, a polyurethane resin, a silicon resin, and the like. Two or more types may be mixed and used. When these thermosetting resins are employed as the matrix resin, it is possible to add an appropriate curing agent or reaction accelerator to the thermosetting resin. In the case of thermoplastic resins, the main materials are polyethylene resin, polypropylene resin, polyvinyl chloride resin, ABS resin, polystyrene resin, AS resin, polyamide resin, polyacetal resin, polycarbonate resin, thermoplastic polyester resin, PPS (polyphenylene sulfide). ) Resin, fluororesin, polyetherimide resin, polyetherketone resin, polyimide resin and the like can be exemplified, and only one kind may be used or two or more kinds may be mixed and used. These thermoplastic resins may be used alone, as a mixture, or as a copolymer. In the case of a mixture, a compatibilizer may be used in combination. Further, brominated flame retardants, silicon-based flame retardants, red phosphorus and the like may be added as flame retardants. For structural members for automobiles that are required to be relatively mass-produced, it is preferable to use a thermoplastic resin from the viewpoint of ease of molding and mass productivity. In this case, examples of the thermoplastic resin used include polyolefin resins such as polyethylene and polypropylene, polyamide resins such as nylon 6 and nylon 66, polyester resins such as polyethylene terephthalate and polybutylene terephthalate, polyether ketone, Resins such as polyether sulfone and aromatic polyamide can be used. Among them, the plastic matrix resin is preferably at least one selected from the group consisting of polyamide, polyphenylene sulfide, polypropylene, polyether ether ketone, and phenoxy resin.

  As described above, according to the energy absorbing member according to the present invention, a specific metal outer surface forming structure is secured between the outer panel and the inner panel, and the specific arrangement structure of the specific fiber-reinforced resin reinforcing member is used for an automobile. As a structural member, it is possible to develop excellent energy absorption performance while suppressing a decrease in load that can be handled.

It is a perspective view (Drawing 1 (A)) of an energy absorption member concerning one embodiment of the present invention, and a transverse cross section (Drawing 1 (B)) which meets a BB line of Drawing 1 (A). It is a disassembled perspective view of the energy absorption member of FIG. 7 is a schematic side view (FIG. 3A) showing an example of a modification of the energy absorbing member of FIG. 1 and a schematic side view (FIG. 3B) showing an example of a modification of the conventional energy absorbing member shown in FIG. . It is a schematic side view which shows an example of the destruction mode of the reinforcement member of the energy absorption member of FIG. It is a schematic comparison figure of the load-stroke characteristic of a reinforcing member made of fiber reinforced resin (carbon fiber reinforced resin [CFRP]) and a reinforcing member made of metal (STEEL). It is a perspective view (Drawing 6 (A)) showing an example of the conventional structural member for motor vehicles, and a transverse cross section (Drawing 6 (B)) which meets a BB line of Drawing 6 (A).

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 shows an energy absorbing member according to an embodiment of the present invention. An energy absorbing member 1 shown in FIG. 1 has a metal outer panel 2 and a metal inner panel 3, and a fiber reinforced resin is formed in a hollow region 4 formed by the outer panel 2 and the inner panel 3. It consists of the structural member for motor vehicles which has arrange | positioned the reinforcing member 5 made from. The reinforcing member 5 is formed in a hollow closed cross section in cross section, and is bonded and fixed to at least the inner surface of the inner panel 3. In this embodiment, the reinforcing member 5 made of fiber reinforced resin is disposed so as to be in contact with the outer panel 2, and is also bonded and fixed to the inner surface of the outer panel 2. As shown in FIG. 2, the outer panel 2, the inner panel 3, and the reinforcing member 5 each have the same cross-sectional shape and continuously extend in the longitudinal direction of the automobile structural member. However, in the present embodiment, they are formed in the same cross-sectional shape, but in actuality, a cross-sectional variation form in consideration of the design and the fastening structure is also possible.

  In such an energy absorbing member 1 according to this embodiment, the outer panel 2 and the inner panel 3 secure a metal outer surface forming structure of a structural member for an automobile, and the hollow formed by both the members 2 and 3. A lightweight fiber-reinforced resin reinforcing member 5 is disposed in the region 4. Since the cross section of the reinforcing member 5 is formed in a hollow closed cross-sectional shape, the reinforcing member 5 has high rigidity as the member itself, and it is disposed between the outer panel 2 and the inner panel 3. As a result, an excellent reinforcing performance for the structural member for an automobile is exhibited without a significant increase in weight.

  The reinforcing member 5 made of fiber reinforced resin can exhibit higher energy absorption performance than the reinforcing member made of metal. As shown in FIG. 3 in comparison with a modification when a bending load is applied, the energy absorbing member 1 having the fiber-reinforced resin reinforcing member 5 shown in FIG. 1 (FIG. 3A) has a bending load. When P is added, it is possible to receive the load P without accompanying a large cross-sectional deformation. However, in the conventional structural member 100 (energy absorbing member) shown in FIG. )), When the load P increases and exceeds the yield point of the material, the load that can be handled is greatly reduced, and a large cross-section deformation (cross-section deformed portion 104) is generated. Decrease significantly.

  Since the fiber reinforced resin reinforcing member 5 is bonded and fixed to at least the inner panel 3, the outer panel 2 is also bonded and fixed in the present embodiment, so that the fiber reinforced resin reinforcing member 5 is securely sandwiched between the members 2 and 3. Thus, breakage in the cross-sectional direction is unlikely to proceed, and cross-sectional deformation can be suppressed, and a reduction in load that can be handled is suppressed. Further, when the bending load P is applied, for example, as shown in FIG. 4, the fractured portion 10 of the fiber reinforced resin reinforcing member 5 is in a state where both side portions thereof are in contact with each other. By shifting to the axial compression mode, sequential fracture characteristics are exhibited, and excellent energy absorption performance is exhibited.

  Such excellent energy absorption performance is manifested by utilizing the sequential fracture characteristics in the compression mode inherent to the fiber reinforced resin constituting the reinforcing member 5. For example, FIG. 5 shows a comparison of load-stroke (displacement) characteristics of a reinforcing member 21 made of fiber reinforced resin (carbon fiber reinforced resin [CFRP]) and a reinforcing member 22 made of metal (STEEL). The CFRP reinforcing member 21 can take on a substantially constant load even when the compression failure progresses and the stroke (displacement amount) increases from the point where the maximum load Pmax is exceeded, and can continue to absorb energy stably. However, in the case of the reinforcing member 22 made of metal (STEEL), the load is suddenly reduced with an increase in the stroke (displacement amount), and high energy absorption performance cannot be obtained. Such excellent energy absorption performance is obtained particularly when the fiber reinforced resin reinforcing member 5 is sandwiched between the inner panel 3 and the outer panel 2, and in particular, the fiber reinforced resin reinforcing member 5 is at least on the inner panel 3. It is expressed in a state of being bonded and fixed, preferably in a state of being bonded and fixed to the outer panel 2 as well.

  As described above, in the present invention, by arranging the reinforcing member made of fiber reinforced resin in a specific form between the inner panel and the outer panel, desirable reinforcing performance of the structural member for automobile can be obtained and excellent energy can be obtained. Absorption performance is developed.

  The structure of the energy absorbing member according to the present invention can be applied to any automotive structural member, and can be applied to any automotive structural member that requires energy absorption, such as front pillars, center pillars, and bumper beams. It is.

DESCRIPTION OF SYMBOLS 1 Energy absorption member 2 Metal outer panel 3 Metal inner panel 4 Hollow area | region 5 Reinforcement member 10 made from fiber reinforced resin Fracture part 21 of reinforcement member made from fiber reinforced resin CFRP reinforcement member 22 STEEL reinforcement member P Load

Claims (5)

  A structural member for an automobile in which a reinforcing member made of fiber reinforced resin is arranged in a hollow region formed by a metal outer panel and a metal inner panel, and the reinforcing member has a hollow closed cross-sectional shape And an energy absorbing member that is bonded and fixed to at least the inner panel.   The energy absorbing member according to claim 1, wherein the reinforcing member is disposed so as to contact the outer panel.   The energy absorbing member according to claim 1, wherein the reinforcing member is also bonded and fixed to the outer panel.   The said outer panel, the said inner panel, and the said reinforcement member are extended in the longitudinal direction of the said structural member for motor vehicles, The cross section of the said reinforcement member has the said hollow closed cross-sectional shape, Any one of Claims 1-3 An energy absorbing member according to any one of the above.   The energy absorption member according to any one of claims 1 to 4, comprising carbon fiber as a reinforcing fiber used in the fiber reinforced resin.

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