JP7248936B2 - curved panel member - Google Patents

Description

The present invention relates to the construction of curved panels.

A panel having a curvature (hereinafter referred to as a “curved panel”) is a metal panel having a curved surface as a whole, such as a door outer panel, a roof panel, a hood, a fender, a side outer panel, etc. of an automobile. In the development of automobiles, in order to reduce weight for the purpose of improving fuel efficiency, efforts are being made to reduce the thickness of steel sheets, for example, which are used as materials for curved panels. On the other hand, the thinning of the steel plate lowers the tensional rigidity of the curved panel, so it is required to reinforce the curved panel in order to ensure sufficient tensional rigidity.

As a structure for reinforcing a curved panel, Patent Document 1 discloses a curved panel member in which an FRP (fiber reinforced resin) sheet is attached to a metal plate. In the curved panel member of Patent Document 1, the shape of the FRP sheet is appropriately changed to improve the restoring performance when the curved panel is deformed. In addition, Patent Document 2 discloses that CFRP is bonded to a range of 1 to 30% of the panel area, and the load when the center of the panel is pressed is distributed to the edge of the panel on the side where the CFRP is bonded. It is

JP-A-2001-253371 JP 2018-016171 A

Although various FRP sheet shapes are disclosed in Patent Document 1, giving a shape to the FRP sheet in order to obtain a reinforcing effect significantly increases the manufacturing process of the FRP sheet and reduces productivity. Invite. Therefore, it is desirable to reinforce curved panels in other ways. Moreover, in Patent Document 2, only the load is dispersed when the center of the panel is pushed, and it is difficult to fundamentally improve the tension rigidity.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a new curved surface panel member capable of improving tension rigidity.

One aspect of the present invention for solving the above problems is a curved panel member comprising a metal curved panel and continuous fibers bonded to the curved panel, and a matrix resin is a thermoplastic resin. a reinforcing member consisting of FRP layers, each of the plurality of FRP layers having one fiber direction, and at least one of the plurality of FRP layers having a fiber direction different from that of the other layers. , defining the maximum principal curvature direction of the curved panel as the 0 ° direction and the direction orthogonal to the 0 ° direction as the 90 ° direction, and the fiber direction of each layer of the reinforcing member joined to the curved panel, When the 0° direction component and the 90° direction component are calculated using a trigonometric function, the 0° direction component is 40% of the fiber direction components of the continuous fibers contained in the entire FRP layer. It is characterized by the above.

The "curved panel" according to the present invention is, for example, a panel having a curved surface such as a door outer panel, roof panel, hood, fender, or side outer panel of an automobile. The curved panel also includes a panel that has a curved surface as a whole even if a part of the panel has a flat surface.

ADVANTAGE OF THE INVENTION According to this invention, the new curved-surface panel member which can improve tension rigidity can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS It is a perspective view which shows schematic structure of the curved-surface panel member which concerns on the 1st Embodiment of this invention. It is the perspective view which looked at the curved-surface panel member of FIG. 1 from the back side. It is a figure which shows the vehicle-body structure example of a motor vehicle. FIG. 4 is a diagram for explaining the layer structure of the reinforcing member according to the first embodiment; It is a figure for demonstrating the layer structure of the reinforcement member which concerns on 2nd Embodiment. It is a figure for demonstrating the calculation method of the ratio of the 0 degree direction component of a fiber direction. It is a figure which shows an example of the layered structure of the reinforcing member which concerns on 2nd Embodiment. It is a figure which shows an example of the layered structure of the reinforcing member which concerns on 2nd Embodiment. It is a figure which shows the example of joining of a curved surface panel and a reinforcement member. FIG. 4 is a diagram showing conditions for evaluating tension stiffness; 4 is a graph showing evaluation results of tension stiffness. 4 is a graph showing evaluation results of tension stiffness. 4 is a graph showing evaluation results of tension stiffness. 4 is a graph showing evaluation results of tension stiffness.

An embodiment of the present invention will be described below with reference to the drawings. In the present specification and drawings, elements having substantially the same functional configuration are denoted by the same reference numerals, thereby omitting redundant description.

<First Embodiment: Single Fiber Direction>
As shown in FIGS. 1 and 2, the curved panel member 1 of the first embodiment is composed of a curved panel 2 made of metal and a reinforcement member 3 made of CFRP and joined to the curved panel 2 . Although the material of the metal curved panel 2 is not particularly limited, for example, a steel plate, an aluminum alloy plate, a magnesium alloy plate, or the like is used. From the viewpoint of improving tension rigidity and dent resistance, the curved panel 2 is preferably made of a steel plate of 440 MPa or more. The curved panel 2 is, for example, a part such as a door outer panel, a roof panel, a hood, a fender, or a side outer panel as shown in FIG. good.

The curved panel 2 is obtained by processing a flat plate. Therefore, at the stage when the curved panel 2 is manufactured, the shape and material of the product are specified, and the application is also determined. For this reason, it is possible to identify the surface of the front side surface and the back side surface of the curved panel 2 that is frequently subjected to a load from the out-of-plane direction when used as a product. For example, in the case of an automobile door outer panel, if the front surface is the outside surface and the back surface is the inside surface, the load from the outside direction is greater on the outside surface than on the inside surface. is frequently entered. That is, in the example shown in FIG. 1, the side of the door outer panel to which the reinforcing member 3 is joined, which is indicated by the transparent line, is the inner surface of the door outer panel. In this specification, of the front side surface and the back side surface of the curved panel 2, the surface on the side to which the load from the out-of-plane direction as described above is frequently input is referred to as the "load input side surface". In the present embodiment, of the curved surfaces 2a and 2b of the curved panel 2, the curved surface 2a, which is the surface on the side with the smaller curvature, will be described below as the surface on the load input side. , the curved surface 2b, which is the surface on the side with the larger curvature, may be the surface on the load input side.

The reinforcing member 3 of the first embodiment is joined to the surface 2b of the curved panel 2 opposite to the load input side. Although the method of joining the reinforcing member 3 to the curved panel 2 is not particularly limited, for example, it is joined using an adhesive.

(Example of reinforcing member)
FRP that can be used for a reinforcing member (also called an FRP member) means a fiber-reinforced resin composed of a matrix resin and a composite reinforcing fiber material contained in the matrix resin.

As the reinforcing fiber material, for example, carbon fiber and glass fiber can be used. In addition, boron fiber, silicon carbide fiber, aramid fiber, etc. can be used as the reinforcing fiber material. In the FRP used for the FRP member, as the reinforcing fiber base material that is the base material of the reinforcing fiber material, for example, a cloth material using continuous fibers, a unidirectional reinforcing fiber base material (UD material), etc. can be used. . These reinforcing fiber substrates can be appropriately selected depending on the orientation of the reinforcing fiber material.

CFRP is FRP using carbon fiber as a reinforcing fiber material. For example, PAN-based or pitch-based carbon fibers can be used. The CFRP carbon fibers are preferably pitch-based carbon fibers having a high elastic modulus. According to the reinforcing member 3 made of pitch-based carbon fiber, a higher reaction force can be obtained, and tension rigidity can be improved.

GFRP is FRP using glass fiber as a reinforcing fiber material. It is inferior to carbon fiber in mechanical properties, but can suppress electric corrosion of metal members.

Both thermosetting resins and thermoplastic resins can be used as matrix resins for FRP. Thermosetting resins include epoxy resins, unsaturated polyester resins, vinyl ester resins, and the like. Thermoplastic resins include polyolefins (polyethylene, polypropylene, etc.) and acid-modified products thereof, polyamide resins such as nylon 6 and nylon 66, thermoplastic aromatic polyesters such as polyethylene terephthalate and polybutylene terephthalate, polycarbonates, and polyethersulfones. , polyphenylene ether and modified products thereof, polyarylates, polyetherketones, polyetheretherketones, polyetherketoneketones, styrene resins such as vinyl chloride and polystyrene, and phenoxy resins. In addition, the matrix resin may be formed of a plurality of types of resin materials.

Considering application to metal members, it is preferable to use a thermoplastic resin as the matrix resin from the viewpoint of workability and productivity. Furthermore, by using a phenoxy resin as the matrix resin, the density of the reinforcing fiber material can be increased. In addition, since the phenoxy resin has a similar molecular structure to that of the epoxy resin, which is a thermosetting resin, it has heat resistance equivalent to that of the epoxy resin. Moreover, by further adding a curing component, application to a high-temperature environment becomes possible. When a curing component is added, the amount to be added may be appropriately determined in consideration of the impregnating properties of the reinforcing fiber material, the brittleness of the FRP, the tact time, the workability, and the like.

<Adhesive resin layer>
When the reinforcing member is formed of an FRP member or the like, an adhesive resin layer is provided between the FRP member and the metal member (the curved panel 2 in the above embodiment), and the FRP member and the metal member are joined by the adhesive resin layer. may be

The type of adhesive resin composition forming the adhesive resin layer is not particularly limited. For example, the adhesive resin composition may be either a thermosetting resin or a thermoplastic resin. The types of thermosetting resin and thermoplastic resin are not particularly limited. For example, thermoplastic resins include polyolefins and acid-modified products thereof, polystyrene, polymethyl methacrylate, AS resins, ABS resins, thermoplastic aromatic polyesters such as polyethylene terephthalate and polybutylene terephthalate, polycarbonates, polyimides, polyamides, and polyamides. Use one or more selected from imide, polyetherimide, polyethersulfone, polyphenylene ether and modified products thereof, polyphenylene sulfide, polyoxymethylene, polyarylate, polyetherketone, polyetheretherketone, and polyetherketoneketone, etc. can do. As the thermosetting resin, for example, one or more selected from epoxy resins, vinyl ester resins, phenol resins, and urethane resins can be used.

The adhesive resin composition can be appropriately selected according to the properties of the matrix resin, the properties of the reinforcing member, or the properties of the metal member that constitute the FRP member. For example, by using a resin having a polar functional group or a resin subjected to acid modification or the like as the adhesive resin layer, the adhesiveness is improved.

By bonding the FRP member to the metal member using the adhesive resin layer described above, the adhesion between the FRP member and the metal member can be improved. By doing so, it is possible to improve the deformation followability of the FRP member when a load is input to the metal member. In this case, the effect of the FRP member on the deformed body of the metal member can be exhibited more reliably.

The form of the adhesive resin composition used for forming the adhesive resin layer can be, for example, powder, liquid such as varnish, or solid such as film.

A crosslinkable adhesive resin composition may also be formed by blending a crosslinkable curable resin and a crosslinker with the adhesive resin composition. Since this improves the heat resistance of the adhesive resin composition, it can be applied in a high-temperature environment. As the cross-linkable curable resin, for example, a bifunctional or higher functional epoxy resin or a crystalline epoxy resin can be used. Amines, acid anhydrides, and the like can also be used as cross-linking agents. In addition, the adhesive resin composition may contain other additives such as various rubbers, inorganic fillers, solvents, etc., as long as the adhesiveness and physical properties are not impaired.

Combining the FRP member with the metal member is realized by various methods. For example, it can be obtained by bonding an FRP to be an FRP member or an FRP molding prepreg that is a precursor thereof and a metal member with the adhesive resin composition described above and solidifying (or curing) the adhesive resin composition. . In this case, the FRP member and the metal member can be combined by, for example, thermocompression bonding.

Adhesion of the FRP or FRP molding prepreg to the metal member may be performed before, during or after molding of the part. For example, after molding a metal material, which is a work material, into a metal member, FRP or a prepreg for FRP molding may be adhered to the metal member. Also, after bonding FRP or FRP molding prepreg to a work material by thermocompression bonding, the work material to which the FRP member is bonded may be molded to obtain a composite metal member. If the matrix resin of the FRP member is a thermoplastic resin, it is also possible to perform molding such as bending on the portion where the FRP member is adhered. In addition, when the matrix resin of the FRP member is a thermoplastic resin, composite batch molding may be performed in which the thermocompression bonding process and the molding process are integrated.

It should be noted that the method of joining the FRP member and the metal member is not limited to adhesion using the adhesive resin layer described above. For example, the FRP member and metal member may be mechanically joined. More specifically, fastening holes are formed in corresponding positions of the FRP member and the metal member, and the FRP member and the metal member are fastened by fastening means such as bolts and rivets through the holes. The member may be joined. Alternatively, the FRP member and the metal member may be joined by a known joining means. Also, the FRP member and the metal member may be joined in a composite manner by a plurality of joining means. For example, adhesion by the adhesive resin layer and fastening by fastening means may be used in combination.

<Metal member and its surface treatment>
The metal member according to the present invention may be plated. This improves corrosion resistance. In particular, it is more suitable when the metal member is steel. The type of plating is not particularly limited, and known plating can be used. For example, galvanized steel sheets (steel materials) include hot-dip galvanized steel sheets, hot-dip alloyed galvanized steel sheets, Zn-Al-Mg-based alloy-plated steel sheets, aluminum-plated steel sheets, electro-galvanized steel sheets, electro-Zn-Ni-based alloy-plated steel sheets, and the like. can be used.

In addition, the surface of the metal member may be coated with a film called chemical conversion treatment. This further improves corrosion resistance. As the chemical conversion treatment, generally known chemical conversion treatments can be used. For example, zinc phosphate treatment, chromate treatment, chromate-free treatment, or the like can be used as the chemical conversion treatment. Further, the film may be a known resin film.

Also, the metal member may be coated with a generally known coating. This further improves corrosion resistance. A known resin can be used as the coating. For example, as the coating, a coating made mainly of epoxy resin, urethane resin, acrylic resin, polyester resin, fluorine-based resin, or the like can be used. In addition, generally known pigments may be added to the coating as needed. Also, the coating may be a clear coating to which no pigment is added. Such coating may be applied to the metal member in advance before compositing the FRP member, or may be applied to the metal member after compositing the FRP member. Alternatively, the metal member may be coated in advance, then the FRP member may be composited, and then coated. The paint used for coating may be a solvent-based paint, a water-based paint, a powder paint, or the like. As a coating method, a generally known method can be applied. For example, as a coating method, electrodeposition coating, spray coating, electrostatic coating, dip coating, or the like can be used. Electrodeposition coating is suitable for coating end faces and gaps of metal members, and is therefore excellent in corrosion resistance after coating. Further, by subjecting the surface of the metal member to a generally known chemical conversion treatment such as zinc phosphate treatment or zirconia treatment before coating, the coating film adhesion is improved.

FIG. 4 is a diagram for explaining the layered structure of the reinforcing member 3. As shown in FIG. Here, in this specification, the maximum principal curvature direction of the curved panel 2 is defined as the "0° direction", and the direction perpendicular to the 0° direction when facing the curved surface on which the 0° direction is defined is "90° direction". ° direction”. In the curved panel member 1 shown in FIG. 4, the reinforcing member 3 has a six-layer structure of CFRP, and the continuous fibers of each layer of the reinforcing member 3 are oriented in the direction of 0°. A layer in which continuous fibers are oriented in a specific direction is referred to herein as an "oriented layer." For example, a layer in which fibers are oriented in the 0° direction (the direction of maximum principal curvature of the curved panel 2) is referred to as a 0° oriented layer. That is, the reinforcing member 3 shown in FIG. 4 has six 0° orientation layers 3a. The total number of layers constituting the reinforcing member 3 is not particularly limited, and may be appropriately changed according to the shape of the curved panel 2, the required tension rigidity, and the like. In this embodiment, the reinforcing member 3 may be composed of a single layer of CFRP. Also, the size of the reinforcing member 3, the plate thickness of each layer, the joint position with respect to the curved panel 2, etc. are not particularly limited, and can be appropriately changed according to the shape of the curved panel 2, the required tension rigidity, and the like.

The curved panel member 1 is constructed as described above. In the case of the curved panel 2 as shown in FIG. 1, when a load F is input from the out-of-plane direction to the surface 2a of the curved panel 2 on the load input side, substantially circular distortion occurs around the load input position. The inventors have found that in such a case, the tension rigidity is improved when the fibers of the reinforcing member 3 joined to the curved panel 2 are oriented in the direction of 0° rather than in the direction of 90°. Found it. That is, the tensional rigidity of the curved panel member 1 can be improved more in the reinforcing member 3 in which each layer is composed of 0° oriented layers 3a than in the reinforcing member 3 in which each layer is composed of 90° oriented layers. In the curved panel member 1 shown in FIG. 4, all the layers of the reinforcing member 3 are 0° orientation layers 3a, so that the tensile rigidity of the curved panel member 1 can be effectively improved.

The fiber direction of the continuous fibers of the reinforcing member 3 does not necessarily have to match the 0° direction as in the example shown in FIG. Orientation is sufficient. Even in this case, it is possible to sufficiently improve the tensional rigidity of the curved panel member 1 . From the viewpoint of effectively improving the tensional rigidity of the curved panel member 1, the fiber direction is more preferably oriented toward the 0° direction within the range of −15° to 15°. The fiber direction in the orientation layer 3a can be identified by observing and analyzing the fiber-reinforced resin member using microfocus X-ray computed tomography (CT). The fiber direction with respect to the 0° direction is obtained from the fiber direction of the orientation layer 3a and the relative direction relationship of the reinforcing member 3 including the orientation layer 3a to the curved panel 2 in the joined state with the curved panel 2.

<Second Embodiment: Multiple Fiber Direction>
In the first embodiment, the fiber direction of each layer of the reinforcing member 3 is unidirectional, but in the second embodiment, the reinforcing member 3 has two or more types of orientation layers. That is, in the reinforcing member 3 according to the second embodiment, each of the plurality of CFRP layers constituting the reinforcing member 3 has one fiber direction, and at least one of the plurality of CFRP layers has a different fiber direction. It is a structure having a fiber direction different from that of the layer. In the case of the curved panel member 1 shown in FIG. 5, the reinforcing member 3 has a six-layer structure in which the 0° orientation layer 3a and the 90° orientation layer 3b are mixed. In the reinforcing member 3, four layers near the surface 2b opposite to the load input side of the curved panel 2 are 0° orientation layers 3a, and the remaining two layers are 90° orientation layers 3b. The curved panel member 1 of the second embodiment has the same configuration as the curved panel member 1 of the first embodiment, except that the reinforcing member 3 has two or more types of orientation layers. In the present embodiment, the “θ° oriented layer” also includes an oriented layer containing continuous fibers oriented at θ±5°. For example, the "0° oriented layer" is not only an FRP oriented layer in which the fiber direction of the continuous fibers strictly indicates the 0° direction, but also is oriented at -5° to 5° with respect to the 0° direction. It is also meant to include orientation layers comprising continuous fibers.

As described in the first embodiment, the reinforcing member 3 preferably includes more 0° orientation layers 3a, but in addition to the 0° orientation layers 3a as in the second embodiment, It is more preferable to have an orientation layer other than 3a. As described above, when the load F is input from the out-of-plane direction to the surface 2a on the load input side of the curved panel 2, substantially circular distortion occurs around the load input position. By providing an orientation layer other than the 0° orientation layer 3a, it is possible to suppress distortion that cannot be suppressed only by the 0° orientation layer 3a. Thereby, the tension rigidity of the curved panel member 1 can be further improved. The fiber direction of the continuous fibers of the reinforcing member 3 is not limited to the 0° direction and the 90° direction, and may be, for example, ±45° direction or ±60° direction. The fiber directions to be combined are appropriately changed according to the shape of the curved panel 2, the required tension rigidity, and the like.

When the reinforcing member 3 has two or more types of orientation layers, the ratio of the 0° direction component in the entire layer of the reinforcing member 3 is preferably 40% or more, more preferably 50% or more. As a result, the tensional rigidity of the curved panel member 1 can be effectively improved. For example, the ratio of 0° oriented layers may be 40% or more of the entire FRP layers. Specifically, as shown in FIG. 5, when there are six layers of FRP, four layers are 0° orientation layers 3a, so that the ratio of 0° orientation layers to the entire FRP layer is 66% or more. In such a case, the tensile rigidity of the curved panel member 1 can be effectively improved.

(Method for calculating ratio of 0° direction component)
In this specification, the ratio of the 0° direction component (the component parallel to the maximum principal curvature direction of the curved panel 2) is calculated as follows. Here, an example is shown in which two types of fiber directions are included in the entire FRP layer that constitutes the reinforcing member 3 joined to the curved panel 2 . First, for each of the first fiber direction having an angle (acute angle) θ ₁ with the 0° direction and the second fiber direction having an angle (acute angle) θ ₂ with the 0° direction as shown in FIG. , using a trigonometric function to decompose into a 0° direction component and a 90° direction component, and calculate the absolute value of the 0° direction component value per layer and the absolute value of the 90° direction component value per layer. . Next, the value of the 0° direction component in the entire layer is calculated by totaling the 0° direction component of each layer. Similarly, by summing the 90° direction components of each layer, the value of the 90° direction component in the entire layer is calculated. Then, the values of the 0° direction component and the value of the 90° direction component in the entire layer calculated here are summed up, and the ratio of the 0° direction component in the entire layer to the total value is calculated.

For example, when the angle θ ₁ is 30°, cos 30° is the 0° direction component and sin 30° is the 90° direction component. That is, the 0° direction component per layer is about 0.866, and the 90° direction component per layer is 0.5. When the reinforcing member 3 has a 6-layer structure, the 0° direction component in the entire layers is 5.2, and the 90° direction component is 3.0. The value of 5.2, which is the value of the 0° direction component of the entire layer, is about 63% of the total value of 8.2 of the 0° direction component and the 90° direction component of the entire layer. is the ratio of the 0° direction component in When the fiber direction is the 0° direction, the value of the 0° direction component is cos 0°, that is, 1, and the value of the 90° direction component is sin 0°, that is, 0. When the fiber direction is 90°, the value of the 0° direction component is cos 90°, ie, 0, and the value of the 90° direction component is sin 90°, ie, 1.

When each layer of FRP has substantially the same thickness, the ratio is calculated by the method described above. For example, if _xk is the value of the 0° direction component of the k-th layer from the junction side of the n-layer FRP, and _tk is the thickness of the layer, the total value of the 0° direction component in the entire layer is _x1 * _t1 +...+ _xn * _tn . The total value of the 90° directional components is similarly obtained.

In this specification, the portion of the reinforcing member 3 located on the joint side with the curved panel 2 is “bent” with respect to the center (neutral plane) of the thickness of the reinforcing member 3 (that is, the total thickness of each layer). The part located opposite the joining side is called the "outer bending part". It should be noted that the “bending inner portion” and “bending outer portion” referred to here are not defined as a result of actually bending the curved panel member 1, but are defined geometrically based on the neutral plane of the reinforcing member 3. It is a thing. In the reinforcing member 3 shown in FIG. 7, five layers near the surface 2b on the side opposite to the joint side with the curved panel 2 are the 90° orientation layers 3b, and the remaining one layer is the 0° orientation layer 3a. That is, in the example shown in FIG. 7, the bending inner portion has three 90° oriented layers 3b, and the bending outer portion has two 90° oriented layers 3b and one 0° oriented layer 3a.

In the curved panel member 1 shown in FIG. 7, the 0° oriented layer 3a is less than the entire layer, but the 0° oriented layer 3a is included on the curved outer side from the neutral plane of the curved panel member 1. As shown in FIG. That is, by arranging the 0° oriented layer 3a on the outer side of bending where the tensile stress increases, the tensile rigidity of the curved panel member 1 is effectively improved even if the ratio of the 0° oriented layer 3a to the entire layer is small. can be made From the viewpoint of improving tension rigidity, the ratio of the 0° direction component in the entire layers included in the bending outer portion is preferably 30% or more, more preferably 50% or more. In addition, the ratio of the 0° direction component in the bending outer portion is 30% or more, and the ratio of the 0° direction component in the entire layer of the reinforcing member 3 is 40% or more, preferably 50% or more. , the tension stiffness can be further improved.

In the description of the second embodiment, the number of fiber directions is two, but the number of fiber directions may be three or more. For example, the reinforcing member 3 shown in FIG. ° orientation layer 3a. Even in such a case, since the reinforcing member 3 contains the 0° direction component, the tensional rigidity of the curved panel member 1 can be improved. Further, as described above, from the viewpoint of improving tension rigidity, the ratio of the 0° direction component in the entire layers included in the bending outer portion is preferably 30% or more, more preferably 50% or more. In addition, the ratio of the 0° direction component in the bending outer portion is 30% or more, preferably 50% or more, and the ratio of the 0° direction component in the entire layer of the reinforcing member 3 is 40% or more, preferably 50% or more. By satisfying the conditions, the tension rigidity can be further improved.

The description of the first and second embodiments is as above. Even if the reinforcing member 3 is joined to the surface 2a of the curved panel 2 on which the main load is assumed, the effect of improving the tension rigidity can be obtained. It is preferably joined to the surface 2b opposite to 2a. For example, when the curved panel 2 is a part such as a door outer panel, a roof panel, a hood, a fender, or a side outer panel of an automobile, a load F from the out-of-plane direction is input to the surface 2a of the curved panel 2 on the load input side. Therefore, the tensile stress on the surface 2b on the side opposite to the load input side of the curved panel 2 increases. It is possible to effectively reinforce the portion where tensile stress is generated. This makes it easier to obtain the effect of improving the tension rigidity of the curved panel 2 .

Moreover, it is preferable that the reinforcing member 3 is joined to the entire surface of the curved panel 2 . For example, even if the reinforcing member 3 is partially joined to the curved panel 2, it is possible to partially improve the tension rigidity, but the reinforcing member is not joined to the entire surface of the curved panel 2. As a result, the stiffening effect of the reinforcing member 3 can be obtained no matter where the load is applied to the curved panel 2 .

In addition, the reinforcing member 3 obtained by focusing on the orientation in the 0° direction as in the first and second embodiments has the same shape as the FRP sheet of Patent Document 1 described above, for example. However, the stiffening effect exhibited is greater than that of the FRP sheet of Patent Document 1. That is, if it is sufficient to obtain a stiffening effect equivalent to the stiffening effect of Patent Document 1 depending on the product specification, for example, the thickness of the reinforcing member 3 is reduced to reduce the weight of the curved panel member 1. is also possible. For this reason, for example, when joining the reinforcing member 3 to the entire surface of the curved panel 2 as in the first and second embodiments, compared to joining a plurality of conventional FRP sheets over the entire panel, the panel member It is possible to reduce the weight and ensure sufficient tension rigidity.

Although the embodiments of the present invention have been described above, the present invention is not limited to such examples. It is obvious that a person skilled in the art can conceive various modifications or modifications within the scope of the technical idea described in the claims, and these are also within the technical scope of the present invention. be understood to belong to

<Evaluation result (A): Single fiber direction>
The tensile rigidity of the curved panel member 1 according to the present invention was evaluated by the method shown in FIG. In this evaluation method, a reinforcing member 3 having a six-layer structure is joined to the entire inner surface of the curved panel 2 . In addition, tension stiffness was evaluated under different fiber orientation conditions as shown in Table 1 below. In addition, as a comparative example, the tension rigidity was also evaluated under the condition that the reinforcing member 3 was not joined. The reinforcing member 3 is made of CFRP, has a thickness of 0.2 mm per layer, or 1.2 mm in total, and has a Young's modulus of 102 GPa. The steel plate has a thickness of 0.4 mm and a tensile strength of 590 MPa.

As shown in FIG. 10, it was carried out by pressing a hemispherical indenter 10 of R50 into the central portion of the surface 2a of the curved panel 2 on the load input side. Then, the load required to push the indenter 10 by 2 mm was compared under each condition. The higher the load value, the less likely the curved panel 2 is to deform, that is, the higher the tensile rigidity of the curved panel member 1 .

FIG. 11 is a graph showing evaluation results of CASE 2 to CASE 8. As shown in FIG. 11, the load value when the fiber direction was 0° was 1.5 times or more that when it was 90°. Considering this evaluation result, it is possible to effectively improve the tensile rigidity of the curved panel member when the fiber direction is oriented in the -15° to 15° direction.

<Evaluation result (B): direction of multiple fibers>
Next, in the case of having two or more types of orientation layers, the tension stiffness was evaluated under the same load input conditions as in the above evaluation result (A). The fiber orientation under each condition is shown in Table 2 below.

FIG. 12 is a graph showing evaluation results of CASE 9 to CASE 11. FIG. Under the conditions of CASE 9 to CASE 11, among the six layers of the reinforcing member, the proportions of the 0° orientation layer and the 90° orientation layer are different. CASE with a low proportion of 33% and only a 0° orientation layer
Compared to 2, the tension stiffness decreased. In CASE 10 and CASE 11, which are examples of the present invention in which the proportion of the 0° direction component in the entire layer is 50% or more, the tensile stiffness was improved compared to CASE 2 having only the 0° orientation layer. In view of this result, in order to effectively improve the tension rigidity, it is preferable that the reinforcing member has a plurality of layers with different fiber directions, and the 0 ° direction component in the entire layer is 40% or more. More preferably 50% or more.

FIG. 13 is a graph showing the evaluation results of CASE 12 and CASE 13. Under the conditions of CASE 12 and CASE 13, the ratio of 0° oriented layers to 90° oriented layers is small. On the other hand, CASE
Under the conditions of 12 and CASE 13, the 0° orientation layer is located in the layer on the side of the large curvature with respect to the thickness center of the reinforcing member, and the ratio of the 0° direction component in the layer on the large curvature side is 30%. That's it. As shown in FIG. 13, in CASE 12 and CASE 13, the tensile rigidity can be further improved compared to CASE 2. Considering this result, in order to effectively improve the tension rigidity, the reinforcing member has two or more types of orientation layers, and the layer on the side with a large curvature with respect to the thickness center of the reinforcing member has 0 ° The ratio of the directional component is preferably 30% or more, more preferably 50% or more, of the layer on the larger curvature side. Further, if the ratio of the 0° direction component contained in the layer on the large curvature side is 30% or more of the layer on the large curvature side, and the ratio of the 0° direction component in the entire layer is 40% or more, It is speculated that the tension rigidity can be further improved.

FIG. 14 is a graph showing evaluation results of CASE 14 and CASE 15. FIG. The CASE 14 and CASE 15 conditions include alignment layers other than 0° and 90° alignment layers. As a result of calculating the 0° direction component from the angle formed with the 0° direction by the method using the trigonometric function described above, CASE 14 and CASE 15 have a 0° direction component of 40% or more in the entire layer, and The ratio of the 0° direction component in the layer on the larger curvature side is 30% or more. As shown in FIG. 14, the tensile rigidity is improved compared to CASE 2 under any conditions. Considering this result, even if an orientation layer other than the 0 ° orientation layer and the 90 ° orientation layer is included, the 0 ° direction component in the entire layer is 40% or more, or the layer on the side with a large curvature is 0 ° If the ratio of the component in the ° direction is 30% or more, the tensional rigidity can be effectively improved.

INDUSTRIAL APPLICABILITY The present invention can be used as a structure for automobile door outer panels, roof panels, hoods, fenders, side outer panels, and the like.

1 Curved Panel Member 2 Curved Panel 2a Load Input Side Surface 2b of Curved Panel Surface 3 Reinforcing Member 3a 0° Orientation Layer 3b 90° Orientation Layer 3c 45° Orientation Layer 3d −45° Orientation layer 10 Indenter C Thickness center of reinforcing member

Claims (8)

curved metal panels,
a reinforcing member composed of a plurality of FRP layers, the matrix resin of which is a thermoplastic resin, and which contains continuous fibers and is bonded to the curved panel;
Each of the plurality of FRP layers has a single fiber direction,
At least one layer of the plurality of FRP layers exhibits a fiber direction different from that of the other layers,
The maximum principal curvature direction of the curved panel is defined as the 0° direction, and the direction orthogonal to the 0° direction is defined as the 90° direction, and the fiber direction of each layer of the reinforcing member joined to the curved panel is expressed by a trigonometric function When the 0° direction component and the 90° direction component are calculated using There is a curved panel member. 2. The curved surface according to claim 1, wherein the FRP layer containing continuous fibers oriented within 5° with respect to the 0° direction accounts for 40% or more of the entire FRP layers of the reinforcing member. panel material. 2. The ratio of the 0° direction component of the layer included in the portion opposite to the side of the reinforcing member joined to the curved panel with respect to the thickness center of the reinforcing member is 30% or more. 3. The curved panel member according to 2. the curved panel is a door outer panel, a roof panel, a hood, a fender, or a side outer panel;
The curved panel member according to any one of claims 1 to 3, wherein the reinforcing member is joined to a vehicle-interior surface of the curved panel. The curved panel member according to any one of claims 1 to 4, wherein the reinforcing member is joined to the entire surface of the curved panel. The curved panel member according to any one of claims 1 to 5, wherein the curved panel is a steel plate of 440 MPa or more. The curved panel member according to any one of claims 1 to 6, wherein the FRP is CFRP. The curved panel member according to any one of claims 1 to 6, wherein the FRP is GFRP.

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