Integrated molded body for vehicle and method for manufacturing same

Abstract

The present invention easily creates an integrally molded body of a metal layer and a fiber-reinforced resin layer without impairing shielding performance of an electromagnetic wave even in a molded body having a complicated three-dimensional shape. This integrated structure for a vehicle comprises a fiber-reinforced resin layer containing a reinforcing fiber and a resin, and a metal layer. The integrated structure has a top surface part and a standing surface part. The top surface part and the standing surface part are connected to form a corner part. The metal layer has a repeating pattern of a recessed part and a projecting part having a pitch of 1 mm or more and less than 50 mm. The pitch of a repeating pattern outside the corner part is wider than the pitch of a repeating pattern of the top surface part or the standing surface part. The metal layer shields at least one of an electric field and a magnetic field.

Description

Integral molded body for vehicle and manufacturing method thereof

[0001] The present invention relates to an integrally molded body for a vehicle in which a fiber-reinforced resin layer and a metal layer are integrally molded, and a method for manufacturing the same.

[0002] Numerous studies have been conducted on techniques for shielding electric fields using metal and resin. Patent Document 1 describes a resin fiber-reinforced resin layer containing foil-like metal flakes, in which flakes of a laminate of metal foil and plastic film are randomly dispersed and adhered to each other. Patent Document 2 describes a method for molding an electromagnetically shielding resin outer panel, in which a mold for molding the rear surface of the outer panel is formed with irregularities, aluminum foil and SMC (sheet molding compound) are placed on top of each other in the mold, and the aluminum foil is bonded to the resin by heating and pressure molding. Patent Document 3 provides a vehicle body structure that provides electromagnetic shielding while simplifying the manufacturing process by providing a battery box component with a recessed portion where the electromagnetic wave shielding layer does not follow.

[0003] Japanese Unexamined Patent Publication No. 58-84856 Japanese Unexamined Patent Publication No. 4-110278 International Publication No. 2021 / 125386

[0004] Vehicle structures may be required to have shielding properties for blocking radio waves and magnetic waves. However, the resin fiber reinforced resin layer containing foil-shaped metal flakes described in Patent Document 1 is simply formed by mixing metal flakes into the resin fiber reinforced resin layer, and therefore the metal flakes may flow during molding, resulting in the risk of generating areas that cannot completely block radio waves or magnetic waves.

[0005] Although Patent Document 2 attempts to shape aluminum foil by creating irregularities, it only discloses a method for forming simple shapes such as flat plates. With the forming method described in Patent Document 2, even if an attempt is made to create an integrated fiber-reinforced resin layer having a top surface and a vertical surface, such as a hat shape, it is not possible to shape the aluminum foil by following the resin.

[0006] In Patent Document 3, the electromagnetic wave shielding layer is not adapted to conform to the components of the battery box having recesses. No technology has been considered for making the shielding layer conform to recesses or deep-drawn portions. To install the shielding layer so that it conforms to a fiber-reinforced resin layer with a complex shape, the shielding layer must be pre-formed and then bonded to the fiber-reinforced resin layer, which increases the number of assembly steps. Furthermore, if an attempt is made to simultaneously mold a metal plate (flat plate) and a molding material without pre-forming in order to prevent the increase in steps, there is a problem of the shielding layer becoming misaligned.

[0007] An object of the present invention is to easily produce an integrally molded body of a metal layer and a fiber-reinforced resin layer without impairing the electromagnetic wave shielding performance, even if the molded body has a complex three-dimensional shape.

[0008] As a result of extensive investigations, the present inventors have found that the above problems can be solved by the following means, and have arrived at the present invention.

[0009] 1. An integrally molded body for a vehicle, comprising a fiber-reinforced resin layer containing reinforcing fibers and resin, and a metal layer, the integrally molded body having a top surface and a vertical surface, the top surface and the vertical surface being connected to form a corner, the metal layer having a repeating pattern of recesses and protrusions at a pitch of 1 mm or more but less than 50 mm, the pitch of the repeating pattern outside the corner being wider than the pitch of the repeating pattern on the top surface or the vertical surface, and the metal layer shielding at least one of an electric field or a magnetic field. 2. The integrally molded body according to 1 above, wherein the metal layer is embedded in the fiber-reinforced resin layer, and the surface of the fiber-reinforced resin layer and the surface of the metal layer are flush with each other. 3. The integrally molded body according to any one of 1 or 2 above, wherein the reinforcing fibers are discontinuous fibers and are dispersed in the in-plane direction of the fiber-reinforced resin layer. The integrally molded body according to any one of 1 to 3 above, wherein the electric field or magnetic field shielding property is 10 decibels or more in at least a portion of the frequency range of 4.0 MHz to 100 MHz. 5. The integrally molded body for a vehicle according to any one of Items 1 to 4, wherein the integrally molded body is a component of a battery box. 6. The integrally molded body according to any one of Items 1 to 5, wherein the metal layer has a through-hole, and the through-hole is crimped and fastened by the resin. 7. The integrally molded body according to any one of Items 1 to 6, wherein the resin is a thermoplastic resin. 8. The integrally molded body according to any one of Items 1 to 7, wherein the repeating pattern is a repeating pattern of parallelograms formed by first mountain folds and first valley folds that are parallel to each other, and second mountain folds and second valley folds that intersect the first mountain folds and first valley folds and are parallel to each other. 9. The integrally molded body according to 8, wherein the repeating pattern is formed by alternating rows of the parallelograms arranged horizontally and mirror images of the rows arranged vertically. 10. The integrally molded body according to any one of Items 1 to 9, wherein the repeating pattern is imparted to the entire surface or a portion of the metal layer. 11. 1. A method for producing the integrally molded body described in 1 above by stacking a molding material containing reinforcing fibers and a resin on a metal plate and press-molding the laminate using an upper molding die and a lower molding die, wherein the integrally molded body is produced through steps 101 to 201.Step 101. A metal plate is prepared, and a repeating pattern of recesses and protrusions having a pitch of 1 mm or more and less than 50 mm is formed by embossing. Step 201. A metal plate and molding material are placed in a lower molding die, and the upper molding die is closed to perform press molding so that the metal plate becomes a metal layer and the molding material becomes a fiber-reinforced resin layer. 12. The method for producing an integrally molded product according to step 11, wherein in step 201, the recesses and protrusions formed by the embossing expand, thereby forming the metal plate into a metal layer having a repeating pattern having a pitch of 1 mm or more and less than 50 mm. 13. The method for producing an integrally molded product according to either one of steps 11 or 12, wherein the maximum depth of the repeating pattern formed by the embossing is 0.5 mm or more. 14. 14. The method for manufacturing an integrally molded body according to any one of claims 11 to 13, wherein the embossing in step 101 involves arranging parallelograms formed by first mountain folds and first valley folds that are parallel to each other and second mountain folds and second valley folds that intersect the first mountain folds and the first valley folds and are parallel to each other, horizontally arranging parallelograms, and forming a repeating pattern on the metal plate in which rows of horizontally arranged parallelograms and their mirror images are alternately arranged vertically. 15. The method for manufacturing an integrally molded body according to any one of claims 11 to 14, wherein in step 201, the molding material is poured so as to contact the lower molding die. 16. The method for manufacturing an integrally molded body according to any one of claims 11 to 14, wherein in step 201, the molding material is poured so as to contact the upper molding die. 17. The method for manufacturing an integrally molded body according to any one of claims 11 to 16, wherein the molding material is a sheet molding compound. 18. 18. The method for manufacturing an integrally molded body according to any one of claims 11 to 17, wherein the breaking elongation of the metal plate is 5% or more and less than 80%.

[0010] Because the metal layer is embossed, it is possible to easily produce an integrally molded vehicle body consisting of the metal layer and the fiber-reinforced resin layer, even if the metal layer has a complex three-dimensional shape, which eliminates the need to prepare a pre-shaped metal layer and also omits the step of bonding the metal layer to the fiber-reinforced resin layer.

[0011] FIG. 1 is a schematic cross-sectional view showing an integrally molded body 1 for a vehicle according to an embodiment of the present invention. FIG. 2 is a schematic diagram showing an example of a method for manufacturing the integrally molded body for a vehicle of the present invention. Before the upper mold is closed. FIG. 3 is a schematic diagram showing an example of a method for manufacturing the integrally molded body for a vehicle of the present invention. The upper mold is closed and pressing the metal layer. The state of shaping using only a metal plate using a molding mold. Before the upper mold is closed. The upper mold is closed and pressing the metal plate. The state of placing only a metal plate in a molding mold and molding. The state of stacking a metal plate and molding material and molding them together. The state of placing only a metal plate in a molding mold and molding. The state of stacking a metal plate and molding material and molding them together. Schematic diagram showing an example of embossing in step 101. Parallelograms formed by first mountain folds and first valley folds parallel to each other and second mountain folds and second valley folds intersecting the first mountain folds and the first valley folds parallel to each other are arranged horizontally, and rows of horizontally arranged parallelograms and their mirror images are arranged vertically alternately to form a repeating pattern on a metal plate. A schematic diagram showing an example of a repeating pattern. Parallelograms formed by first mountain folds and first valley folds parallel to each other and second mountain folds and second valley folds intersecting the first mountain folds and the first valley folds parallel to each other are arranged horizontally, and rows of horizontally arranged parallelograms and their mirror images are arranged vertically alternately. This is an evaluation of the electric field shielding performance of a 150 μm thick polypropylene resin layer. This is an evaluation of the electric field shielding performance of a 150 μm thick aluminum foil. This is an exploded perspective view showing an example of a battery box using an integrally molded body. This is a perspective view showing an example of a battery tray. 10 is a cross-sectional view taken along the line XX in FIG. 9. FIG. 11 is a schematic view showing a dimple-shaped metal plate used in Example 2.

[0012] Hereinafter, embodiments of the present invention will be described, but the present invention is not limited to these.

[0013] [Shape of the integrally molded body] 1. Top surface and vertical surface The structure of the present invention has a top surface and a vertical surface. Specifically, it preferably has at least one flat surface having at least one thickness (plate thickness), and the cross-sectional shape may be T-shaped, L-shaped, U-shaped, hat-shaped (sometimes called a hat shape), or a three-dimensional shape including these, and may further have an uneven shape (for example, a rib, a boss, etc.). The structure produced by the present invention preferably has a shape including a portion whose cross-sectional shape is hat-shaped.

[0014] Fig. 1 is a schematic cross-sectional view showing an integrally molded body 1 for a vehicle according to an embodiment of the present invention. As shown in Fig. 1, the integrally molded body 1 has a fiber-reinforced resin layer 10 and a metal layer 20. The integrally molded body has a top surface portion 2 and a vertical surface portion 3, and the top surface portion 2 and the vertical surface portion 3 are connected to form corner portions 4. The fiber-reinforced resin layer 10 includes reinforcing fibers and resin.

[0015] [Reinforcing Fiber] In this specification, the reinforcing fiber is preferably at least one selected from the group consisting of carbon fiber, aramid fiber, and glass fiber, and more preferably carbon fiber or glass fiber.

[0016] [Reinforcing Fiber: Carbon Fiber] 1. Carbon Fibers in General When using carbon fibers, polyacrylonitrile (PAN)-based carbon fibers, petroleum / coal pitch-based carbon fibers, rayon-based carbon fibers, cellulose-based carbon fibers, lignin-based carbon fibers, phenol-based carbon fibers, etc. are generally known, and any of these carbon fibers can be suitably used in the present invention. Among these, polyacrylonitrile (PAN)-based carbon fibers are preferably used in the present invention because of their excellent tensile strength. As a PAN-based carbon fiber, for example, TENAX (registered trademark) STS40-24KS carbon fiber (average fiber diameter 7 μm) manufactured by Teijin Limited can be used.

[0017] 2. Sizing Agent for Carbon Fiber The carbon fiber used in the present invention may have a sizing agent attached to its surface. When using carbon fiber with a sizing agent attached, the type of sizing agent can be appropriately selected depending on the type of carbon fiber and the type of resin, and is not particularly limited.

[0018] 3. Carbon Fiber and Countermeasures against Galvanic Corrosion When carbon fiber is used, it is preferable to dispose a resin layer between the fiber reinforced resin layer and the metal layer as a countermeasure against galvanic corrosion.

[0019] [Reinforcing Fiber: Glass Fiber] The case where the reinforcing fiber used in the present invention is glass fiber will be described. 1. Glass Fiber in General The glass fiber used in the present invention may be any glass fiber that is generally called glass fiber. There is no particular limitation on the glass composition such as A-glass, C-glass, E-glass, etc., and in some cases TiO ２ , S.O. ３ , P ２ O ５ The glass fiber may contain components such as E-glass RS240QR-483 (count: 2400 g / 1000 m) manufactured by Nitto Boseki Co., Ltd., for example.

[0020] 2. Sizing Agent for Glass Fiber The glass fiber used in the present invention may have a sizing agent attached to its surface. When using glass fiber with a sizing agent attached, the type of sizing agent can be appropriately selected depending on the type of glass fiber and the type of resin, and is not particularly limited. Glass fiber that has been pre-treated with a conventionally known coupling agent such as an organosilane compound, an organotitanium compound, an organoborane compound, or an epoxy compound can be preferably used.

[0021] [Reinforcing fibers: dispersed in the in-plane direction] The reinforcing fibers of the present invention are preferably discontinuous fibers dispersed in the in-plane direction of the fiber-reinforced resin layer. In addition, in order to disperse the reinforcing fibers in the in-plane direction in the fiber-reinforced resin layer, it is preferable to disperse the reinforcing fibers contained in the molding material in the in-plane direction.

[0022] The reinforcing fibers being dispersed in the in-plane direction means that the reinforcing fibers are dispersed so that their fiber axes are oriented in the in-plane direction. It is preferable that the angle between the fiber axes of the reinforcing fibers and the in-plane direction is 45° or less.

[0023] 1. In-plane direction The in-plane direction is an indefinite direction of a parallel plane perpendicular to the plate thickness direction of the molding material or fiber reinforced resin layer. The molding material is preferably a plate-shaped material.

[0024] 2. Random dispersion in two dimensions It is preferable that the reinforcing fibers are randomly dispersed in the in-plane direction in two dimensions. In the region where the molding material is press-molded without flow, the shape of the reinforcing fibers is almost maintained before and after molding. Therefore, it is preferable that the reinforcing fibers contained in the non-flow region of the fiber-reinforced resin layer formed from the molding material are also randomly dispersed in two dimensions in the in-plane direction.

[0025] Here, "two-dimensionally randomly dispersed" refers to a state in which the reinforcing fibers are not oriented in a specific direction such as one direction in the in-plane direction of the molding material or fiber-reinforced resin layer, but are oriented randomly, and are arranged in the sheet plane without showing any specific directionality overall. A molding material (or fiber-reinforced resin layer) obtained using such two-dimensionally randomly dispersed discontinuous fibers is a substantially isotropic molding material (or fiber-reinforced resin layer) that does not have anisotropy in the plane.

[0026] The degree of two-dimensional random orientation is evaluated by determining the ratio of the tensile modulus in two directions perpendicular to each other. If the (Eδ) ratio, calculated by dividing the larger of the tensile modulus values ​​measured in any direction of the molding material (or fiber-reinforced resin layer) and the direction perpendicular thereto by the smaller, is 5 or less, more preferably 2 or less, and even more preferably 1.5 or less, it can be evaluated that the reinforcing fibers are dispersed two-dimensionally randomly.

[0027] When the resin contained in the fiber-reinforced resin layer is a thermoplastic resin and the fiber-reinforced resin layer has a three-dimensional shape including curved surfaces, the two-dimensional random dispersion in the in-plane direction can be evaluated by heating the fiber-reinforced resin layer above its softening temperature to return it to a flat plate shape and then solidifying it. Then, by cutting out a test piece and measuring the tensile modulus, the state of random dispersion in the two-dimensional direction can be confirmed.

[0028] [Reinforcing fiber: fiber length] The reinforcing fiber is preferably a discontinuous fiber. When discontinuous fibers are used, the formability is improved compared to fiber-reinforced plastics using only continuous fibers, and it becomes easier to create a complex fiber-reinforced resin layer.

[0029] Since the weight average fiber length of the reinforcing fibers does not change before and after molding, the weight average fiber length Lw of the reinforcing fibers contained in the molding material can be determined by examining the weight average fiber length of the reinforcing fibers in the fiber reinforced resin layer.

[0030] The weight average fiber length Lw of the reinforcing fibers is preferably 1 mm or more, more preferably 3 mm or more. The weight average fiber length Lw of the reinforcing fibers is more preferably 3 mm or more and 100 mm or less, more preferably 3 mm or more and 80 mm or less, and even more preferably 5 mm or more and 60 mm or less. If the weight average fiber length Lw of the reinforcing fibers is 100 mm or less, the fluidity of the molding material is less likely to decrease when the molding material is press-molded, making it easier to create the desired shape. Furthermore, if the weight average fiber length Lw is 1 mm or more, the mechanical strength of the resulting fiber-reinforced resin layer member is less likely to decrease, which is preferable.

[0031] The weight average fiber length Lw and number average fiber length Ln of the reinforcing fibers can be calculated using the following formulas (1) and (2). In a fiber-reinforced resin layer prepared by injection molding, the weight average fiber length of the reinforcing fibers is approximately 0.1 to 0.3 mm. Therefore, when the weight average fiber length of the reinforcing fibers is 1 mm or more and 100 mm or less, it is preferable to prepare the fiber-reinforced resin layer by press molding.

[0032] In the present invention, discontinuous reinforcing fibers having different fiber lengths may be used in combination. In other words, the discontinuous reinforcing fibers used in the present invention may have a single peak in the weight-average fiber length distribution, or may have multiple peaks.

[0033] [Reinforcing Fibers: Number Average Fiber Length Ln and Weight Average Fiber Length Lw] Generally, when the fiber length of each reinforcing fiber is Li, the number average fiber length Ln and weight average fiber length Lw can be calculated by the following formulas (1) and (2). The units of the number average fiber length Ln and weight average fiber length Lw are mm. Here, "I" indicates the number of reinforcing fibers measured.

[0034] When the fiber length is constant, the number average fiber length and the weight average fiber length are the same value. The reinforcing fibers can be extracted from the fiber-reinforced resin layer by, for example, performing a heat treatment at 500°C for about 1 hour and removing the resin in a furnace.

[0035] The average fiber length can be calculated, for example, by measuring the fiber lengths of 100 fibers randomly extracted from the fiber-reinforced resin layer to the nearest 1 mm using a caliper or the like, and then calculating the average fiber length based on formula (1) or formula (2).

[0036] If short fibers that cannot be measured with a caliper are included, the resin is removed, and the resulting reinforcing fibers are placed in water containing a surfactant and thoroughly stirred with ultrasonic vibration. Samples of the stirred dispersion are randomly collected with a measuring spoon to obtain evaluation samples, and the lengths of 3,000 fibers are measured using a Luzex AP image analyzer manufactured by Nireco Corporation. The measured fiber lengths can be used to calculate the number-average fiber length Ln and the weight-average fiber length Lw in the same manner as in the above-mentioned formulas (1) and (2).

[0037] [Reinforcing fiber: fiber volume ratio] The fiber volume ratio Vf of the reinforcing fiber is not particularly limited, but is preferably 20 to 70%, more preferably 25 to 60%, and even more preferably 30 to 55%. The fiber volume ratio (Vf, unit: volume %) is the ratio of the volume of the reinforcing fiber to the total volume including not only the reinforcing fiber and resin but also other additives.

[0038] ​Although there are no limitations on the analysis of the reinforcing fiber volume fraction, it is recommended to measure it as follows. A sample is cut out from the fiber-reinforced resin layer, and the resin is burned off in a furnace at 500°C for 1 hour. The mass of the sample before and after treatment is weighed to calculate the mass of the reinforcing fiber, resin, and other additives. Next, the volume fraction of the reinforcing fiber and resin is calculated using the specific gravity of each component. Vf = 100 x reinforcing fiber volume / (reinforcing fiber volume + resin volume + other additives)

[0039] [Resin] The resin contained in the fiber-reinforced resin layer or the resin contained in the resin layer disposed between the fiber-reinforced resin layer and the metal layer may be thermosetting or thermoplastic. 1. Thermoplastic Resin When the resin used is a thermoplastic resin, the type is not particularly limited, and a resin having a desired softening point or melting point can be appropriately selected and used. As the above-mentioned thermoplastic resin, one having a softening point in the range of 180°C to 350°C is usually used, but is not limited thereto.

[0040] Examples of thermoplastic resins include polyolefin resins, polystyrene resins, polyamide resins, polyester resins, polyacetal resins (polyoxymethylene resins), polycarbonate resins, (meth)acrylic resins, polyarylate resins, polyphenylene ether resins, polyimide resins, polyethernitrile resins, phenoxy resins, polyphenylene sulfide resins, polysulfone resins, polyketone resins, polyether ketone resins, thermoplastic urethane resins, fluorine-based resins, and thermoplastic polybenzimidazole resins.

[0041] The thermoplastic resin used in the fiber-reinforced resin layer of the present invention may be one type or two or more types. Examples of the use of two or more thermoplastic resins in combination include a use of thermoplastic resins having different softening points or melting points, and a use of thermoplastic resins having different average molecular weights. However, this is not limited to this.

[0042] When a thermoplastic resin is used, it is more preferable to use a polyolefin resin, and even more preferable to use a polypropylene resin.

[0043] 2. Thermosetting Resin The resin may be a thermosetting resin. When a thermosetting resin is used, it is preferably an unsaturated polyester resin, a vinyl ester resin, an epoxy resin, or a phenol resin. One type of resin may be used alone, or two or more types may be used in combination.

[0044] Furthermore, when a thermosetting resin is used as the resin of the present invention, a sheet molding compound (sometimes referred to as SMC) containing reinforcing fibers may be used. Due to its high moldability, a sheet molding compound can be easily molded into even complex shapes. Compared to continuous fibers, a sheet molding compound has higher fluidity and shaping properties, making it easy to create ribs and bosses.

[0045] [Other Agents] The resin used in the molding material may contain additives such as various fibrous or non-fibrous fillers such as organic or inorganic fibers, flame retardants, UV-resistant agents, stabilizers, mold release agents, pigments, softeners, plasticizers, surfactants, etc., within the scope of the present invention. When a thermosetting resin is used, it may contain thickeners, curing agents, polymerization initiators, polymerization inhibitors, etc. One type of additive may be used alone, or two or more types may be used in combination.

[0046] [Integral Molding] The integrally molded vehicle body of this embodiment is formed by integrally molding a fiber-reinforced resin layer containing reinforcing fibers and resin with a metal layer. Here, the integrally molded body is formed by integrally molding a fiber-reinforced resin layer containing reinforcing fibers and resin with a metal layer. "Integral molding" refers to a seamless, continuous molding, rather than a molding formed by joining separate components. This type of integral molding is created in a single molding operation, preferably by press molding. Because it is created by integral molding, separate parts can be processed as a single part, reducing the unit price of the part. Furthermore, the number of assembly steps is reduced, and the reduced number of parts also reduces inventory costs. "Integral molding" is sometimes referred to as "comolding." Because the integrally molded body is integrally molded, it can also be simply referred to as a "vehicle structure."

[0047] 2A and 2B are schematic diagrams showing an example of a method for manufacturing the integrally molded body 1. First, as shown in FIG. 2A, a fiber-reinforced resin 404 is placed on a lower mold 401. Next, a metal plate 403 is placed on the fiber-reinforced resin 404. As will be described later, the metal plate 403 has been embossed in advance. Next, as shown in FIG. 2B, an upper mold 402 is lowered, and the fiber-reinforced resin 404 and the metal plate 403 are sandwiched between the lower mold 401 and the upper mold 402 and pressed. In this manner, the integrally molded body 1 is manufactured.

[0048] [Advantages of Integral Molding] 1. Issues with the Prior Art When a metal plate is shaped separately without integral molding, the unevenness of the mold (the unevenness used to shape the metal plate) tends to cause tearing, particularly at the corners of the metal plate. This is due to the fact that the metal plate (e.g., aluminum foil) stretches at the corners beyond its breaking elongation. A tear-prone area is shown as 501 in Figure 3B. To improve yield, the area shown as 501 in Figure 3B has traditionally required reinforcement by applying cushioning or reinforcing material such as gum tape to prevent tearing. Furthermore, when deep drawing is performed on the metal plate 403, not just at corners like 501 in Figure 3B, the area tends to wrinkle. Alternatively, the metal layer design needs to be designed to soften the sharpness of the corners.

[0049] 2. Effect of Integral Molding (i) On the other hand, when a fiber-reinforced resin layer and a metal layer are integrally molded, the fiber-reinforced resin can take over the role of a buffer. This is a synergistic effect of integrally molding the embossed metal layer and the fiber-reinforced resin, preventing the metal plate from coming into contact with the corners of the molding die and making it less likely to tear. For example, when molding only the metal plate 403 without laminating the fiber-reinforced resin, as shown in Figure 4A, the corner α of the molding die must be gently curved to prevent the metal plate 403 from being broken by the corner α. On the other hand, when the fiber-reinforced resin 404 is placed in the lower mold and the metal plate 403 is laminated on top of the fiber-reinforced resin 404 to integrally mold the metal plate 403 and the fiber-reinforced resin 404, as shown in Figure 4B, the fiber-reinforced resin 404 acts as a buffer, making the metal plate 403 less likely to tear, and eliminating the need to gently curve the corner β of the lower mold. The same is true for Figures 5A and 5B. For example, when molding is performed using only metal plate 403 without laminating fiber-reinforced resin as shown in Fig. 5A, it is necessary to provide a gentle curve at corner γ of the upper mold so that corner γ does not tear metal plate 403. On the other hand, when metal plate 403 is placed in the lower mold and fiber-reinforced resin 404 is laminated on top of metal plate 403 to integrally mold metal plate 403 and fiber-reinforced resin 404 as shown in Fig. 5B, fiber-reinforced resin 404 acts as a buffer material, making metal plate 403 less likely to tear, and there is no need to provide a gentle curve at corner δ of the upper mold.

[0050] 3. Effect of integral molding (ii) When the resin contained in the fiber reinforced resin is a thermoplastic resin and cold press molding is used, if a metal plate 403 is placed in the lower mold and the fiber reinforced resin 404 is layered so that it contacts the upper mold, as shown in Figure 5B, the fiber reinforced resin 404 will not cool to the mold temperature until just before it contacts the upper mold. This makes it easier to impart ribs and bosses to the fiber reinforced resin 404, improving the design.

[0051] 4. Effect of integral molding (iii) The metal layer 20 is embedded in the integrally molded body 1, and it is preferable that the surface of the integrally molded body 1 and the surface of the metal layer 20 are flush with each other. In this case, there is no step at the interface between the integrally molded body 1 and the metal layer 20, resulting in a flat shape. The interface may be flush with the top surface 2 or the vertical surface 3 of the integrally molded body 1. Since the end of the metal layer 20 is embedded in the resin of the fiber-reinforced resin layer during integral molding, chipping at the end of the metal layer 20 can also be reduced.

[0052] [Method for manufacturing an integrally molded body for a vehicle] The integrally molded body for a vehicle of the present invention may be manufactured by laminating a fiber-reinforced resin containing reinforcing fibers and a resin and a metal plate, and press-molding the laminated laminate using upper and lower molds. In this case, it is preferable to manufacture the integrally molded body for a vehicle through steps 101 to 201.

[0053] [Type of Metal Plate] The type of metal plate that becomes the metal layer 20 after forming is not particularly limited, and examples thereof include pure aluminum, aluminum alloys containing magnesium (Mg), copper (Cu), zinc (Zn), silicon (Si), manganese (Mn), etc., pure copper, copper alloys containing nickel (Ni), tin (Sn), zinc (Zn), aluminum (Al), lead (Pb), phosphorus (P), etc., pure magnesium, magnesium alloys containing aluminum (Al), zinc (Zn), manganese (Mn), zirconium (Zr), etc., and conductive carbon such as graphite foil. Aluminum, aluminum alloys, copper, and copper alloys are particularly preferred. In this specification, the metal plate is the one before forming and becomes the metal layer after forming. The breaking elongation of the metal plate is preferably 5% or more and less than 80%. Here, the breaking elongation of the metal plate refers to the breaking elongation measured when the metal plate that becomes the metal layer 20 is subjected to the tensile testing method for metallic materials specified in JIS Z2241:2011. The breaking elongation of a metal plate is measured based on the thickness of the metal plate used. For example, when a metal plate with a thickness of 0.2 mm is used, the breaking elongation of the 0.2 mm thick metal plate is measured. Specifically, a test piece having a length of 120 mm and a parallel portion of 20 mm wide is prepared from the 0.2 mm thick metal plate, and a tensile test is performed until the test piece breaks with an original gauge length Lo = 80 mm. When the final gauge length of the test piece after break is Lu, the breaking elongation is the permanent elongation after break (Lu - Lo) expressed as a percentage of the original gauge length Lo. When the breaking elongation of the metal layer 20 is 5% or more but less than 80%, the metal layer is less likely to break after molding using a molding die.

[0054] [Method for manufacturing an integrally molded body: Step 101] Step 101 is a step of preparing a metal plate and embossing it to form a repeating pattern of recesses and protrusions having a pitch of 1 mm or more and less than 50 mm. There is no particular limitation on the thickness of the prepared metal plate, but it is preferably 10 μm or more and 300 μm or less, more preferably 15 μm or more and 250 μm or less, and even more preferably 20 μm or more and 230 μm or less.

[0055] 1. Embossing (1) Embossing generally refers to a process for creating a three-dimensional raised pattern, such as forming recesses and / or protrusions in the shape of a circle, triangle, or hemisphere. There are no particular limitations on the embossing method, but embossing is also known as "embossing," and is a processing method in which a design is raised on the surface of a metal plate. Embossing can use both concave and convex metal plates, and when a metal plate is sandwiched between the concave and convex plates and pressed firmly, the surface appears raised and the back appears concave.

[0056] (2) Embossing Method There is no limitation on the embossing method, but the following steps can be taken as an example for embossing an aluminum plate. (i) Creating a design: Design the shape of the aluminum plate to be embossed. This can be done using CAD software. (ii) Preparing the aluminum plate: Remove any oil or dirt that may be present on the surface of the aluminum plate. (iii) Embossing: Emboss the area to be processed. An embossing tool is used and pressed against the aluminum plate, giving the aluminum an uneven appearance. A sheet metal die may also be prepared and the aluminum plate may be pressed under pressure. (iv) Finishing: A finishing process is carried out to prevent scratches on the aluminum surface. A painting process may also be included.

[0057] (3) Embossed Shape It is preferable to form a repeating pattern having a pitch of 1 mm or more and less than 50 mm on the metal plate by embossing. Here, the pitch of the repeating pattern is the surface length from the highest point of the convex portion to the lowest point of the concave portion. An example of the pitch distance of the repeating pattern is shown in 901 of FIG. 6A. In 901 of FIG. 6A, the pitch distance is the distance from the peak of the convex portion to the bottom of the concave portion. In FIG. 6A, a repeating pattern consisting of a series of parallelograms of the same shape is depicted, so the pitch is uniform, but it is not necessarily required that all pitches have the same length.

[0058] The repeating pattern preferably has a pitch of 1 mm or more but less than 40 mm, more preferably 2 mm or more but less than 30 mm, and even more preferably 3 mm or more but less than 10 mm. A pitch of less than 50 mm prevents the distance between the upper and lower recesses and protrusions (e.g., 901 in FIG. 6A, the distance between the peak and valley) from becoming too large, making it easier to follow the shape of the fiber-reinforced resin layer during integral molding. A shorter pitch makes it easier to follow the corners of the fiber-reinforced resin layer. On the other hand, a pitch of 1 mm or more allows the repeating pattern created by embossing in step 201 to be easily expanded. In other words, a pitch of 1 mm or more makes it easier to achieve the maximum depth of the repeating pattern because the pitch is not too fine.

[0059] The maximum depth of the repeated pattern formed by embossing is preferably 0.5 mm or more, more preferably 0.7 mm or more, even more preferably 1.0 mm or more, and even more preferably 1.5 mm or more. Here, the maximum depth of the repeated pattern refers to the clearance length between two parallel flat plates when a metal plate having the repeated pattern is sandwiched between them. A maximum depth of 0.5 mm or more facilitates conforming to the shape of the fiber-reinforced resin during integral molding. The maximum depth of the repeated pattern formed by embossing is preferably 1200 to 1600% of the metal plate thickness. Since the maximum depth of the repeated pattern depends on the thickness of the metal plate, this range is preferable because it reduces the risk of breaking the metal plate. The maximum depth of the irregularities refers to the clearance length between the two parallel flat plates when the embossed metal plate is sandwiched between them. Schematic diagrams of preferred embossed metal plates are shown in Figures 6A and 6B. As shown in Figure 6B, the embossing is preferably performed by arranging parallelograms formed by first mountain folds 601 and first valley folds 602, which are parallel to each other, and second mountain folds 603 and second valley folds 604, which intersect with the first mountain folds 601 and first valley folds 602, alternating rows 610 of parallel parallelograms and their mirror images 620, vertically, to create a concave-convex shape. The embossed metal plate with these folds easily unfolds during pressing (step 201). Furthermore, because the folds of the metal plate do not overlap, unnecessary force is not applied, making the plate less likely to tear.

[0060] Since it is preferable that the repeating pattern be disposed over the entire surface or a portion of the metal layer, it is also preferable that the embossing be performed over the entire surface or a portion of the metal plate. It is more preferable that the embossing be performed over the entire surface of the metal plate. In addition to FIG. 6A , dimples may be formed on the metal plate by embossing, as shown in FIG. 11 , for example. Here, "dimples" include recesses 1101 and protrusions 1102 shown in FIG. 11 . This is because protrusions viewed from one side of the metal layer correspond to recesses viewed from the other side of the metal layer. In FIG. 11 , recesses 1101 and protrusions 1102 are alternately arranged in a two-dimensional direction on the surface of the metal layer. When dimples are formed on the metal plate, it is preferable that the diameter of the circumscribing circle of the dimples be as small as possible. Specifically, the diameter of the circumscribing circle of the dimples is preferably 0.3 mm or more and 3.0 mm or less, and more preferably 0.5 mm or less and 2.0 mm or less. If the diameter of the circumscribed circle of the dimple is small, the metal plate can easily conform to the molding die during integral molding, even if the integrally molded product has a small shape. A deeper dimple is preferable from the perspective of simultaneously molding the fiber-reinforced resin and the metal plate. This is because the deeper the dimple, the more easily the metal plate stretches. Specifically, a dimple depth of 0.1 mm or more and 10 mm or less is preferable, and a depth of 0.5 mm or more and 5 mm or less is more preferable. The total area of ​​the dimples should be approximately 50% of the projected area of ​​the metal plate. Here, the total area of ​​the dimples is the product of the area of ​​the plane enclosed by the outline of each dimple and the total number of dimples. Furthermore, the "projected area of ​​the metal plate" is the projected area of ​​the metal plate on a plane parallel to the flat surface of the metal plate excluding the dimple shapes. The thickness t1 of the dimple portion of the metal plate and the thickness t2 of the portion of the metal plate other than the dimples preferably satisfy t1≦t2, and more preferably satisfy t1≦t2≦1.2×t1. If the thickness t1 of the dimpled portion is too thin, it will break, but if it is too thick, the weight of the integrally molded product will increase. To create a metal plate designed to fall within the above preferred range of t1 and t2, the process of adding dimples to the metal plate can be divided into several stages.For example, when dimples are to be formed on a 1000 mm long x 1000 mm wide metal plate, the metal plate is first divided into five regions at a pitch of 1000 mm long x 200 mm wide. First, dimples are formed in the central region (1000 mm long x 200 mm wide), followed by two regions adjacent to the central region. Finally, dimples are preferably formed in both end regions. When dimples are formed by embossing, the surface area of ​​one side of the metal plate preferably satisfies the following relationship: 1.1 x (projected area of ​​the metal plate) < surface area of ​​one side of the metal plate < 3.0 x (projected area of ​​the metal plate). Here, the "surface area of ​​one side of the metal plate" refers to the entire area of ​​one side of the metal plate, including the surface of the dimples. Within the above range, the metal plate can be easily integrally molded without tearing, even when the molded body is deep-drawn or has a portion surrounded by three sides. When dimples are formed on the surface of a metal plate, the pitch is the distance between the centers of the circumscribed circles of the dimples. In Fig. 11, the circumscribing circles of the dimples are uniform in size, but the sizes of the circumscribing circles of the dimples do not have to be uniform. Also, in Fig. 11, the centers of the circumscribing circles of the dimples are equally spaced, but the centers of the circumscribing circles of the dimples do not have to be equally spaced. An example of a metal plate having dimples formed thereon is shown schematically in Fig. 11.

[0061] (4) Miura Folding: Embossing may be used to create a shape similar to Miura Folding (registered trademark). Miura Folding is a folding technique that creates a three-dimensional structure by folding a flat piece of paper (a metal plate in this invention) along the dot-dash lines in Figure 6B into mountain folds and along the dashed lines into valley folds. Alternating valley and mountain folds creates folds that are not perpendicular to each other. Because the folds do not overlap in the folded state, the paper or metal plate can easily transform from a flat surface into a three-dimensional shape. Miura Folding is highly flexible, easy to carry when folded, and can occupy a larger area when unfolded. For this reason, Miura Folding has been widely used in bending structure applications. It has been applied to, for example, automobile airbags, solar panels, maps, and clothing.

[0062] 2. Through holes When embossing, through holes may be made in the metal plate. These through holes can be used as holes into which fiber reinforced resin can enter during press molding and for caulking and fastening.

[0063] [Method for Manufacturing an Integral Molded Body: Step 201 (Press Molding)] Step 201 involves placing a metal plate and a fiber-reinforced resin into a mold and press-molding the metal plate into a metal layer and the fiber-reinforced resin into a fiber-reinforced resin layer. 1. Embossing and Repeated Patterns In step 201, the unevenness created by embossing preferably spreads, resulting in a metal layer having a repeating pattern with a pitch of 1 mm or more and less than 50 mm. For example, when a metal plate is embossed as shown in FIG. 6A, the metal layer formed from the metal plate spreads into a crease pattern as shown in FIG. 6B. In other words, if a crease pattern as shown in FIG. 6B is observed when viewing an integrally molded body for a vehicle, it can be determined that the embossed metal plate had the shape shown in FIG. 6A.

[0064] 2. Metal Plate and Fiber-Reinforced Resin When placing the metal plate and fiber-reinforced resin in a molding die, there are no particular limitations on the method of stacking the metal plate and fiber-reinforced resin, but since the metal plate of the present invention has high conformability to the fiber-reinforced resin, it is recommended that the two be stacked with the same size. If partial shielding is desired, the metal plate may be made smaller and placed in a partial area.

[0065] 3. Stacking Order of Fiber-Reinforced Resin and Metal Plates There are no particular limitations on the stacking order of fiber-reinforced resin and metal plates. However, when the resin contained in the fiber-reinforced resin is a thermoplastic resin and cold press molding is performed, stacking the fiber-reinforced resin so that it comes into contact with the upper molding die improves the design of the fiber-reinforced resin and makes it easier to mold complex uneven shapes (such as ribs and bosses). This is because the (relatively high temperature) fiber-reinforced resin is not cooled by the (relatively low temperature) upper molding die until just before molding pressure is applied. Stacking the fiber-reinforced resin so that it comes into contact with the upper molding die is also preferable from the perspective that the (relatively low temperature) lower molding die will not cool the fiber-reinforced resin because the metal plate is in contact with the lower molding die.

[0066] In terms of the corners of the molding die, if it is desired to integrally mold the corner β of the lower mold in Fig. 4B in a relatively sharp state rather than a gently curved one, it is sufficient to laminate the fiber-reinforced resin and metal plate so that the fiber-reinforced resin comes into contact with the lower molding die. Conversely, if it is desired to integrally mold the corner δ of the upper mold in Fig. 5B in a relatively sharp state rather than a gently curved one, it is sufficient to laminate the fiber-reinforced resin and metal material so that the fiber-reinforced resin comes into contact with the upper molding die.

[0067] 4. Hot Press Molding and Cold Press Molding In the present invention, it is preferable to perform press molding so that the metal plate becomes the metal layer and the fiber reinforced resin becomes the fiber reinforced resin layer. As the press molding method (sometimes called compression molding) in the present invention, molding methods such as hot press molding and cold press molding can be used.

[0068] 4.1 Cold Press Molding When a thermoplastic resin is used as the resin, press molding using cold press is preferred. In the cold press molding method, for example, a fiber-reinforced resin heated to a first predetermined temperature and a metal plate are placed in a mold set to a second predetermined temperature, and then pressurized and cooled. The metal plate does not necessarily need to be heated, but it may be better to heat it to improve the adhesion strength with the fiber-reinforced resin.

[0069] Specifically, if the thermoplastic resin contained in the fiber-reinforced resin is crystalline, the first predetermined temperature is equal to or higher than the melting point, and the second predetermined temperature is lower than the melting point. If the thermoplastic resin is amorphous, the first predetermined temperature is equal to or higher than the glass transition temperature, and the second predetermined temperature is lower than the glass transition temperature. That is, the cold press method includes at least the following steps A-1) to A-2). Step A-1) If the thermoplastic resin is crystalline, heating is performed from the melting point to the decomposition temperature, or if the thermoplastic resin is amorphous, heating is performed from the glass transition temperature to the decomposition temperature. Step A-2) The fiber-reinforced resin heated in step A-1) and a metal plate are placed in a mold whose temperature is adjusted to below the melting point if the thermoplastic resin is crystalline, or below the glass transition temperature if the thermoplastic resin is amorphous, and then pressurized. By performing these steps, the molding of the fiber-reinforced resin and the metal plate can be completed (an integrally molded body can be produced). The above steps must be performed in the order listed above, but other steps may be included between each step. The other step is, for example, a shaping step in which, prior to step A-2), the fiber reinforced resin is pre-shaped into the shape of the cavity of the mold using a shaping mold different from the mold used in step A-2). The shape of at least one of the fiber reinforced resin or the metal plate may be a shape developed by computer inverse molding analysis from the three-dimensional shape of the integrally molded body to be manufactured.

[0070] 4.2 Hot-press molding In hot-press molding, for example, a fiber-reinforced resin is placed in a mold, pressure is applied while the temperature of the mold is raised to a first predetermined temperature, and the mold is cooled to a second predetermined temperature. The metal plate does not necessarily need to be heated, but in some cases it is better to heat it to improve the adhesive strength with the fiber-reinforced resin.

[0071] Specifically, when the thermoplastic resin constituting the fiber-reinforced resin is crystalline, the first predetermined temperature is equal to or higher than the melting point, and the second predetermined temperature is lower than the melting point. When the thermoplastic resin contained in the fiber-reinforced resin is amorphous, the first predetermined temperature is equal to or higher than the glass transition temperature, and the second predetermined temperature is lower than the glass transition temperature. Hot press molding preferably includes at least the following steps B-1) to B-4). B-1) A step of placing the fiber-reinforced resin and a metal plate in a molding die (lower die). B-2) A step of applying pressure while heating the molding die (first pressing step) to a temperature higher than the melting point and lower than the thermal decomposition temperature of the thermoplastic resin if the thermoplastic resin is crystalline, or to a temperature higher than the glass transition temperature and lower than the thermal decomposition temperature of the thermoplastic resin if the thermoplastic resin is amorphous. B-3) A step of applying pressure in one or more stages, with the pressure in the final stage being 1.2 to 100 times the pressure in the first pressing step (second pressing step). B-4) A step of adjusting the mold temperature to below the melting point if the thermoplastic resin is crystalline, or below the glass transition temperature if the thermoplastic resin is amorphous. By performing these steps, an integrally molded structure can be produced.

[0072] 5. Commonalities between cold press molding and hot press molding Steps A-2) and B-3) are steps in which pressure is applied to the fiber-reinforced resin and metal plate to obtain a fiber-reinforced resin layer of the desired shape. The molding pressure at this time is not particularly limited, but it is preferable that it is as low as possible within a range in which the desired structural shape can be obtained. Specifically, it is preferably less than 30 MPa relative to the mold cavity projected area, more preferably 20 MPa or less, and even more preferably 10 MPa or less. A molding pressure of less than 30 MPa is preferable because it does not require capital investment or maintenance costs for a press machine. Naturally, various processes may be inserted between the above steps during compression molding, and for example, vacuum compression molding, in which compression molding is performed while in a vacuum, may be used.

[0073] (Other) When the resin contained in the fiber reinforced resin layer is a thermoplastic resin, if a recess for hooking a metal plate is formed in the fiber reinforced resin before molding, the metal plate can be easily attached whether above or below the fiber reinforced resin.

[0074] [Through holes] The metal layer preferably has through holes, which are preferably crimped and fastened by the resin A. The number of through holes depends on the size of the through holes. If the through holes are small and there are few of them, the shielding effect against the electric field or magnetic field is excellent, but the crimping fastening force is weak. If the through holes are large and there are many of them, the shielding effect against the electric field or magnetic field is reduced, but the crimping fastening force is strong. The area of ​​the through holes is defined as S (m ２ ), the number of through holes is n / m ２ When this is done, it becomes 2 x 10 －６ < S × n < 2 × 10 －５ More specifically, when the through-hole is a circle with a diameter of 1 mm (area S=2.5π×10 －７ m ２ ), the number of through holes is 3 / m ２ When the through-hole is a circle with a diameter of 5 mm (area S = 6.25π × 10 －６ m ２ ), the number of through holes is 1 / m ２ The degree is preferable.

[0075] [Metal Layer: Thickness] In the integrally molded product of the present invention, the thickness of the metal layer is not particularly limited, but is preferably 10 μm to 300 μm, more preferably 15 μm to 250 μm, and even more preferably 20 μm to 230 μm. Furthermore, when an integrally molded product having a hat-shaped cross section as shown in FIG. 1 is produced using a metal plate, the vertical surface portion is stretched by the mold and becomes slightly thinner than the top surface portion. The thickness of the metal layer can be measured using a 10-point average thickness.

[0076] [Metal Layer: Shielding of Electric Field or Magnetic Field] The metal layer of the present invention shields at least one of an electric field or a magnetic field. Furthermore, the metal layer shields at least one of an electric field or a magnetic field, and preferably has an electric field or magnetic field shielding property of 10 decibels or more in at least a portion of the frequency range from 0 MHz to 100 MHz. The electric field or magnetic field shielding property is more preferably 20 decibels or more, and even more preferably 30 decibels or more. Here, the shielding property can be expressed as 10 times the common logarithm (in decibels) of the ratio of the power of the electromagnetic wave before passing through the metal layer to the power of the electromagnetic wave after passing through the shielding layer.

[0077] As a preferred range for each shielding region, the electric or magnetic field shielding property is preferably 10 dB or more, more preferably 20 dB or more, and even more preferably 30 dB or more in at least 50% of the region from 0 MHz to 100 MHz. "In at least 50% of the region from 0 MHz to 100 MHz" means that the shielding region may be continuous or discontinuous in the region from 0 MHz to 100 MHz.

[0078] As a preferred range for each shielding region, in all regions from 0 MHz to 100 MHz, the electric or magnetic field shielding property is preferably 10 decibels or more, more preferably 20 decibels or more, and even more preferably 30 decibels or more.

[0079] The shielding region will be explained using the graphs depicted in Figures 7A and 7B. Figure 7A is a graph of the electric field shielding performance of a 150 μm thick polypropylene resin layer. Figure 7B is a graph of the electric field shielding performance of a 150 μm thick aluminum foil. The horizontal axis in Figures 7A and 7B is frequency (Hz), and the vertical axis is decibels (dB). For example, in the region of 0.1 kHz to 100 MHz in Figure 7A (the region indicated by the arrow 701 in Figure 7A), no electric field is shielded at all in Figure 7A. In the region of 0.1 kHz to 100 MHz in Figure 7B, an electric field shielding performance of approximately 35 to 122 dB is shown.

[0080] [Metal Layer: Comparison with Continuous Fiber Net] One idea for making a metal layer conform to a fiber-reinforced resin is to use continuous metal fibers capable of shielding electric or magnetic fields, form them into a net shape, and laminate them with the fiber-reinforced resin to create a structure. By forming them into a net shape, the extensibility of the metal layer and the extensibility of the fiber-reinforced resin can be made closer, improving moldability. However, if the metal layer is prepared by forming continuous metal fibers into a net shape, the mesh (spaces) of the net will widen during the molding process (also known as gap widening), reducing the shielding ability. The metal layer of the present invention can reduce the effect of reduced shielding ability before and after molding.

[0081] [Repeated Pattern of Metal Layer] The metal layer of the present invention has a repeated pattern of recesses and protrusions with a pitch of 1 mm or more and less than 50 mm. The "repeated pattern of recesses and protrusions" of the present invention includes a "crease pattern." 1. Pitch The pitch of the repeated pattern is preferably 1 mm or more and less than 40 mm, more preferably 2 mm or more and less than 30 mm, and even more preferably 3 mm or more and less than 10 mm. A pitch of less than 50 mm prevents the pitch distance of the embossed uneven shape before pressing from becoming too large, making it easier to follow the shape of the fiber-reinforced resin layer during integral molding. A shorter pitch makes it particularly easy to follow the corners of the fiber-reinforced resin layer. Conversely, a pitch of 1 mm or more can easily widen the uneven shape created by embossing in step 201 during press molding. In other words, a pitch of 1 mm or more makes it easy to achieve the desired depth of the unevenness when embossed because the pitch is not too fine.

[0082] 2. Example of Repeating Pattern An example of a repeating pattern is shown in FIG. 6B. FIG. 6B shows an example of a preferred embodiment of a repeating pattern. Specifically, parallelograms formed by first mountain folds 601 and first valley folds 602, which are parallel to each other, and second mountain folds 603 and second valley folds 604, which intersect with the first mountain folds 601 and first valley folds 602 and are parallel to each other, are arranged horizontally, and a fold is formed in which rows 610 of horizontally arranged parallelograms and mirror images 620 of the rows 610 are arranged vertically. Here, the intersection angle between the first mountain folds 601 or first valley folds 602 and the second mountain folds 603 or second valley folds 604 is not a right angle. Note that in FIG. 6B, the first mountain folds 601 of one parallelogram and the first valley folds 602 of a laterally adjacent parallelogram are alternately connected in a linear manner in the horizontal direction. Additionally, the second mountain folds 603 of vertically adjacent parallelograms are connected to each other in a zigzag pattern in the vertical direction, and the second valley folds 604 of vertically adjacent parallelograms are connected to each other in a zigzag pattern in the vertical direction.

[0083] 3. Repeated Patterns at Corners In the integrally molded body of the present invention, the top and vertical surfaces are connected to form corners. The pitch of the repeating pattern on the outer surface of the corner, in the direction perpendicular to the ridge line of the corner, is wider than the pitch of the repeating pattern on the top or vertical surface. This means that during molding, the embossed metal plate spreads out in the direction perpendicular to the ridge line of the corner at the outer corner of the metal layer compared to other locations. Conversely, the pitch of the repeating pattern on the inner surface of the corner, in the direction perpendicular to the valley line of the corner, is preferably narrower than the pitch of the folds on the top or vertical surface in the direction perpendicular to the valley line of the corner. Here, the "outside" of the corner refers to the side opposite the center of curvature of the corner, and the "inside" refers to the side toward the center of curvature of the corner. It can be confirmed by observing such corners that the metal layer and the fiber-reinforced resin layer are integrally molded rather than molded separately. In the case of integral molding, the pitch of the repeating pattern on the outside of the corner in the direction perpendicular to the ridge line of the corner is generally wider than the pitch of the folds on the top or elevational surface in the direction perpendicular to the ridge line of the corner.

[0084] [Integrated Body: Battery Tray and Battery Cover] The integrated body for a vehicle of the present invention is preferably a component of a battery box. More preferably, the component of the battery box is disposed in the lower part of the vehicle body. FIG. 8 is an exploded perspective view of a battery box 101 using the integrated body of this embodiment. The battery box 101 includes a battery cover 102, a battery 103, a temperature control system (cooling mechanism) 104, a battery tray 105, a reinforcing frame 106, and an energy absorbing member 107. The integrated body of this embodiment can be used for the battery cover 102 or the battery tray 105. The battery 103 is housed in the battery box 101, which includes the battery tray 105 and the battery cover 102.

[0085] [Battery Tray: General] The following describes the use of a battery tray as an integrally molded body for a vehicle. FIG. 9 is a perspective view of a battery tray 105, and FIG. 10 is a cross-sectional view taken along the line X-X in FIG. 9 . As shown in FIGS. 9 and 10 , the battery tray 105 is used to drive an automobile and is configured to mount a battery 103 for driving the vehicle. The battery tray 105 includes a first bottom portion 303 and a peripheral wall 203 extending from the outer periphery of the first bottom portion 303. The battery tray 105 also includes a first inner wall 204 connected to the first bottom portion 303, a second inner wall 205 connected to the first bottom portion 303, and a second bottom portion 301 connected to both the first inner wall 204 and the second inner wall 205 and raised from the first bottom portion. The first bottom portion 303, the peripheral wall 203, the first inner wall 204, the second inner wall 205, and the second bottom portion 301 are configured as part of an integrally molded body for a vehicle.

[0086] [Battery Tray and Metal Layer] When the integrally molded product for a vehicle is a battery box 101, the battery box 101 is provided with a metal layer that shields electric or magnetic fields in order to shield electromagnetic waves generated from the battery 103. The metal layer can shield electromagnetic waves radiated from the battery to prevent external radiation or leakage, ensuring sufficient electromagnetic wave shielding properties for the battery box and making it possible to suppress, for example, adverse effects of electromagnetic waves on the vehicle control system and the human body.

[0087] [Metal Layer: Conforming to Concave Parts] For example, the battery boxes depicted in Figures 9 and 10 have complex shapes, and have large concave parts such as those shown at 313 in Figure 10. How to cover such concave parts with a metal layer is an issue, but the metal layer of the present invention makes it easy to make the metal layer conform to the shape of such concave parts.

[0088] 1. Evaluation (1) A 150 mm x 150 mm test piece (flat plate) was sampled from the shielding integrally molded body, and the electric field shielding property for electromagnetic waves (frequency 0 to 100 MHz) was measured using a network analyzer (manufactured by Keysight Technologies) and a KEC method measuring device (manufactured by JSE). The larger the value, the better the electric field shielding property. Good: The electric field shielding property is 40 decibels or more in the entire range from 0 MHz to 100 MHz inclusive. Bad: The electric field shielding property is 5 decibels or less in the entire range from 0 MHz to 100 MHz inclusive.

[0089] 2. Materials: Metal foil: Aluminum foil manufactured by UACJ Foil Co., Ltd. Polypropylene resin: Novatec PP BC03C manufactured by Japan Polypropylene Corporation (sometimes abbreviated as PP). Glass fiber E-glass RS240QR-483 manufactured by Nitto Boseki Co., Ltd., with a sizing agent attached, was prepared (sometimes abbreviated as GF).

[0090] [Example 1] 1. Embossing of Metal Foil A 0.2 mm thick aluminum foil was embossed using an embossing roll to create a metal foil with the shape shown in FIG. 6A. The metal foil with the shape shown in FIG. 6A was folded using the Miura method. The pitch of the uneven shape (901 in FIG. 6A, the distance between the peak and valley) was 10 mm, and the maximum depth of the uneven shape was 2 mm. Here, the maximum depth of the uneven shape refers to the clearance length between the flat plates when the metal foil with the shape shown in FIG. 6A is sandwiched between two parallel flat plates. Since the depth of the uneven shape provided on the metal foil with the shape shown in FIG. 6A was uniform and 2 mm, the maximum depth was 2 mm.

[0091] 2. Preparation of Fiber-Reinforced Resin. Nitto Boseki's E-glass RS240QR-483 glass fiber was cut to a fiber length of 20 mm. Polypropylene resin (Novatec® PP BC03C, manufactured by Japan Polypropylene Corporation) was used as the resin. Based on the method described in U.S. Patent No. 8,946,342, a composite composition of glass fiber and polypropylene resin with two-dimensionally randomly oriented glass fibers was prepared. Specifically, a breathable support with a suction mechanism attached to the bottom was installed, which moved continuously in one direction. While suction was being performed by the suction mechanism, the glass fiber and polypropylene resin were blown onto the top of the breathable support using compressed air from a tapered tube positioned above the breathable support, creating a composite product in which the glass fiber and polypropylene resin were mixed. The resulting composite composition was heated at 2.0 MPa for 5 minutes in a press heated to 250°C to create a fiber-reinforced resin measuring 600 mm x 1000 mm with an average thickness of 3 mm.

[0092] 3. Integral molding The fiber reinforced resin was heated to 220°C using an infrared heater. Then, the fiber reinforced resin and the metal plate were stacked so that the fiber reinforced resin was in contact with the lower molding die and the metal plate was in contact with the upper molding die, and placed in a molding die. The upper die was lowered and pressed for 1 minute at a pressure of 20 MPa (the time from the start of pressure until 20 MPa was reached was 1 second), and the fiber reinforced resin and the metal plate were pressed simultaneously to produce an integrally molded body having a top surface, a vertical surface, and corners formed by connecting the top surface and the vertical surface.

[0093] [Measurement of pitch in an integrally molded body] Masking tape was applied to the metal layer of the integrally molded body, and marking lines were created on the masking tape along the crease marks on the metal layer. After peeling the masking tape from the metal layer, the distance between the marking lines on the masking tape corresponding to the crease marks was measured. In this case, the measurement was performed for every other parallel marking line. Specifically, one of the parallel marking lines (first line) and one marking line (second line) parallel to and adjacent to the first line were measured, and a marking line adjacent to the opposite side of the first line and parallel to the first and second lines was measured as the third line. This was performed at 10 locations, and the pitch was calculated by dividing the average value by 2. The "shortest distance between the first straight line and the third straight line" corresponds to the shortest distance between adjacent first mountain folds 601, the shortest distance between adjacent first valley folds 602, the shortest distance between adjacent second mountain folds 603, or the shortest distance between adjacent second valley folds 604, as shown in Figure 6B. At the corners where the top and vertical surfaces connect, the spacing between adjacent fold marks in the direction intersecting the ridge of the corner was measured using the above-mentioned method. In the metal layer of the obtained integrally molded body, the pitch of the fold marks on the top and vertical surfaces remained unchanged at 10 mm. Meanwhile, the pitch of the fold pattern on the outer surface of the corner was 11.2 mm. The metal layer conformed to the fiber-reinforced resin layer. The electromagnetic wave shielding property of the integrally molded body of Example 1 was Good.

[0094] [Example 2] 1. Dimple processing of metal plate An aluminum foil having a breaking elongation of 40% at a gauge length of 80 mm, measured by the tensile test method for metal materials specified in JIS Z2241:2011, was prepared. Dimples were provided on the aluminum foil using an embossing roll to create a metal plate having the shape shown in FIG. 11. The metal plate having the shape shown in FIG. 11 was an aluminum foil having a size of 600 mm x 1000 mm x 0.2 mm thick, with multiple dimples provided. The dimples had a diameter of 4 mm, a center-to-center distance of 8.5 mm, and a depth of 1.5 mm. Here, the maximum depth of the dimples refers to the clearance length between the flat plates when the metal plate having the shape shown in FIG. 11 is sandwiched between two parallel flat plates. The depth of the uneven shape provided on the metal plate having the shape shown in FIG. 11 was uniform and 1.5 mm, so the maximum depth was 3.4 mm.

[0095] 2. Preparation of Fiber-Reinforced Resin. Nitto Boseki's E-glass RS240QR-483 glass fiber was cut to a fiber length of 20 mm. Polypropylene resin (Novatec® PP BC03C, manufactured by Japan Polypropylene Corporation) was used as the resin. Based on the method described in U.S. Patent No. 8,946,342, a composite composition of glass fiber and polypropylene resin with two-dimensionally randomly oriented glass fibers was prepared. Specifically, a breathable support with a suction mechanism attached to the bottom was installed, which moved continuously in one direction. While suction was being performed by the suction mechanism, the glass fiber and polypropylene resin were blown onto the top of the breathable support using compressed air from a tapered tube positioned above the breathable support, creating a composite product in which the glass fiber and polypropylene resin were mixed. The resulting composite composition was heated at 2.0 MPa for 5 minutes in a press heated to 250°C to create a fiber-reinforced resin measuring 600 mm x 1000 mm with an average thickness of 3 mm.

[0096] 3. Integral molding The fiber reinforced resin was heated to 220°C using an infrared heater. Then, the fiber reinforced resin and the metal plate were stacked so that the fiber reinforced resin was in contact with the lower molding die and the metal plate was in contact with the upper molding die, and placed in a molding die. The upper die was lowered and pressed for 1 minute at a pressure of 20 MPa (the time from the start of pressure until 20 MPa was reached was 1 second), and the fiber reinforced resin and the metal plate were pressed simultaneously to produce an integrally molded body having a top surface, a vertical surface, and corners formed by connecting the top surface and the vertical surface.

[0097] [Measurement of pitch in an integrally molded body] Masking tape was applied to the metal layer of the integrally molded body, and marking points were created at points corresponding to the centers of the dimples on the masking tape. After peeling the masking tape from the metal layer, the distance between the marking points was measured. This measurement was performed by skipping adjacent marking points. Specifically, for one of the marking points (first point) and another marking point (second point) adjacent to the first point, the marking point adjacent to the first point on the opposite side of the first point was designated as the third point. The shortest distance between the first point and the third point was measured. This was performed at 10 locations, and the average value was divided by 2 to calculate the pitch. At the corners where the top and vertical surfaces connect, the spacing between adjacent dimples in the direction intersecting the ridgeline of the corner was measured using the above method. In the metal layer of the obtained integrally molded body, the dimple pitch on the top and vertical surfaces remained unchanged at 8.5 mm. Meanwhile, the dimple pitch on the outer surface of the corner was 9.5 mm. The metal layer conformed to the fiber reinforced resin layer. The electromagnetic wave shielding property of the integrally molded article of Example 2 was Good.

Claims

1. An integrally molded body for a vehicle, comprising a fiber-reinforced resin layer containing reinforcing fibers and resin, and a metal layer, wherein the integrally molded body has a top surface and a vertical surface, the top surface and the vertical surface are connected to form corners, the metal layer has a repeating pattern of recesses and protrusions with a pitch of 1 mm or more and less than 50 mm, the pitch of the repeating pattern on the outside of the corners is wider than the pitch of the repeating pattern on the top surface or the vertical surface, and the metal layer shields at least one of an electric field or a magnetic field.

2. The integrally molded body according to claim 1, wherein the metal layer is embedded in the fiber-reinforced resin layer, and a surface of the fiber-reinforced resin layer is flush with a surface of the metal layer.

3. An integrally molded body according to claim 1 or 2, wherein the reinforcing fibers are discontinuous fibers and are dispersed in the in-plane direction of the fiber-reinforced resin layer.

4. An integrally molded body according to any one of claims 1 to 3, having an electric or magnetic field shielding property of 10 decibels or more in at least a portion of the range of 0 MHz to 100 MHz.

5. The integrally molded product according to any one of claims 1 to 4, which is a component part of a battery box for a vehicle.

6. An integrally molded body according to any one of claims 1 to 5, wherein the metal layer has a through hole, and the through hole is crimped and fastened by the resin.

7. The integrally molded body according to any one of claims 1 to 6, wherein the resin is a thermoplastic resin.

8. An integrally molded body as claimed in any one of claims 1 to 7, wherein the repeating pattern is a repeating pattern of a parallelogram formed by first mountain folds and first valley folds which are parallel to each other and second mountain folds and second valley folds which intersect the first mountain folds and first valley folds and are parallel to each other.

9. The integrally molded body according to claim 8, wherein said repeating pattern is a vertical array of alternating horizontal rows of said parallelograms and mirror images of said rows.

10. The integrally molded body according to any one of claims 1 to 9, wherein the repeating pattern is applied to the entire surface or a portion of the metal layer.

11. A method for producing the integrally molded body according to claim 1, comprising laminating a fiber-reinforced resin containing reinforcing fibers and resin with a metal plate and press-molding the laminate using an upper molding die and a lower molding die, the method comprising manufacturing the integrally molded body through steps 101 to 201. Step 101: A metal plate is prepared, and a repeating pattern of recesses and protrusions having a pitch of 1 mm or more and less than 50 mm is formed by embossing. Step 201: The metal plate and the fiber-reinforced resin are placed in the lower molding die, and the upper molding die is closed to perform press molding so that the metal plate becomes a metal layer and the fiber-reinforced resin becomes a fiber-reinforced resin layer.

12. The method for manufacturing an integrally molded body described in claim 11, wherein in step 201, the recesses and protrusions formed by the embossing process expand, causing the metal plate to become a metal layer having a repeating pattern with a pitch of 1 mm or more and less than 50 mm.

13. The method for manufacturing an integrally molded product according to claim 11 or 12, wherein the maximum depth of the repeating pattern produced by the embossing is 0.5 mm or more.

14. A method for producing an integrally molded body as described in any one of claims 11 to 13, wherein the embossing in step 101 creates a repeating pattern in which rows of parallelograms formed by first mountain folds and first valley folds that are parallel to each other and second mountain folds and second valley folds that intersect the first mountain folds and first valley folds and are parallel to each other are alternately arranged vertically with mirror images of the rows.

15. A method for producing an integrally molded body according to any one of claims 11 to 14, wherein in step 201, the fiber reinforced resin is poured so as to come into contact with the lower molding die.

16. The method for producing an integrally molded body according to any one of claims 11 to 14, wherein in step 201, the fiber reinforced resin is poured so that the fiber reinforced resin contacts the upper molding die.

17. The method for producing an integrally molded body according to any one of claims 11 to 16, wherein the fiber-reinforced resin is a sheet molding compound.

18. A method for manufacturing an integrally molded body according to any one of claims 11 to 17, wherein the breaking elongation of the metal plate is 5% or more and less than 80%.

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