Insert molded body, battery tray, protective cover for battery tray and inverter box, and method for manufacturing insert molded body

Abstract

The insert-molded body (1) has a resin part (10) and a metal part (20), the resin part (10) has a thickness deviation portion (11) and a thin-walled portion (12) that is thinner than the thickness deviation portion (11), at least a portion of the metal part (20) is arranged on the outer surface of the resin part (10) along the thickness deviation portion (11) or the thin-walled portion (12), the metal part (20) has a direction-changing portion (23) in which the direction of extension on the outer surface is changed, and the resin part (10) and the metal part (20) are fixed to each other at the direction-changing portion (23).

Description

[Technical field]

[0001] The present disclosure relates to an insert-molded article, a battery tray, a protective cover for a battery tray and an inverter box, and a method for manufacturing an insert-molded article. [Background technology]

[0002] An insert-molded product is a molded product produced by placing an insert such as a metal part in a mold and molding it, combining a resin material with a metal material. Because insert-molded products can be produced in a simple process to produce parts with desired structures, they are used in a variety of parts, including automotive parts. Patent Document 1 discloses an insert molding method in which a metal conductive insert part is set in a mold and a thermoplastic resin is injected to form a single piece. Patent Document 2 discloses a method for producing an automotive seatback frame, which includes cold-press molding a fiber-reinforced composite material into the shape of a seatback frame body, and welding a metal plate to the seatback frame body by insert molding during the shaping process. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2015 / 29482 [Patent Document 2] International Publication No. 2013 / 21482 Summary of the Invention [Problem to be solved by the invention]

[0004] For example, an insert-molded product in which a metal part is disposed on a resin part can be used as an impact detection sensor. However, in such an insert-molded product in which a metal part is disposed on a resin part, the metal part may lift off the resin part during molding. If the metal part lifts off, there is a risk that the dimensions of the molded product will be distorted or the performance of the part will be degraded.

[0005] The present disclosure relates to an insert-molded article in which floating of a metal part is reduced, and a method for manufacturing the insert-molded article. [Means for solving the problem]

[0006] An insert molded article according to one embodiment of the present disclosure is An insert-molded product having a resin part and a metal part, the resin part has a thickness deviation portion and a thin-wall portion that is thinner than the thickness deviation portion, at least a portion of the metal part is disposed on the outer surface of the resin part along the uneven thickness portion or the thin thickness portion; The metal part has a deflection portion extending on the outer surface, the deflection portion being changed in direction; The resin part and the metal part are fixed to each other at the deflection portion.

[0007] A method for manufacturing an insert molded article according to an embodiment of the present disclosure includes: A method for manufacturing an insert molded product having a resin part and a metal part, the resin part has a thickness deviation portion and a thin-wall portion that is thinner than the thickness deviation portion, at least a portion of the metal part is disposed on the outer surface of the resin part along the uneven thickness portion or the thin thickness portion; The metal part has a deflection portion extending on the outer surface, the deflection portion being changed in direction; The method includes the step of fastening the plastic component and the metal component to one another at the deflection portion. Effect of the Invention

[0008] According to the insert molded body and the method for manufacturing the insert molded body of the present disclosure, an insert molded body with reduced floating of metal parts can be provided.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

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Figure 6

Figure 7

Figure 8

Figure 9A

Figure 9B

Figure 10

Figure 11

Figure 12

Embodiments for Carrying Out the Invention

[0010] First, embodiments of the present disclosure will be listed and described. An insert molded body according to an embodiment of the present disclosure is (1) An insert molded body having a resin part and a metal part, wherein the resin part has a thick-walled part and a thin-walled part thinner than the thick-walled part, and at least a part of the metal part is disposed on the outer surface of the resin part along the thick-walled part or the thin-walled part, the metal part has a turning part whose extending direction on the outer surface is changed, and the resin part and the metal part are fixed to each other at the turning part.

[0011] When producing an insert molded body with a metal part disposed on a resin part, the metal part may float in the thickness direction (the direction perpendicular to the outer surface of the resin part). Also, when the metal part is cooled, forces that contract in different vectors are generated at the turning part, so the turning part is particularly likely to float. In the insert molded body according to the present embodiment, since the turning part of the metal part is fixed to the resin part, the floating of the metal part can be reduced.

[0012] (2) In the above (1), at least a part of the metal part may be disposed along the thin-walled part.

[0013] In the insert molded body according to the present embodiment, the metal part will be disposed at the top of the convex part provided in the mold in order to form the thin-walled part when being molded. For example, when the metal part is disposed along the convex part (top part) of the lower mold during insert molding and then the resin material is laminated from above and press-molded, when it becomes an insert molded body, the metal part will be disposed along the bottom of the thin-walled part (concave part).

[0014] (3) In the above (1), at least a part of the metal part may be disposed along the thick-walled part.

[0015] In the insert-molded article according to this embodiment, a metal part is placed in a groove provided in a mold to form a thickness-uneven portion during molding. This facilitates positioning of the metal part, making molding easier. For example, if a metal part is placed along the recess (groove) of the lower mold during insert molding, and then a resin material is layered on top and press-molded, the metal part will be positioned along the apex of the thickness-uneven portion (protrusion) when the insert-molded article is formed.

[0016] (4) In any of (1) to (3) above, the metal part may have a first portion extending in a first in-plane direction and a second portion extending in a second in-plane direction different from the first in-plane direction, and the deflection portion may connect the first portion and the second portion.

[0017] The deflection portion connecting the first and second portions extending in different directions is particularly prone to lifting up. According to the insert molding product of this embodiment, such deflection portion is fixed, so that lifting up can be effectively reduced.

[0018] (5) In the above (4), the first in-plane direction and the second in-plane direction may be perpendicular to each other.

[0019] The insert molded article according to this embodiment has a shape that is bent vertically at the direction change portion, and the effect of reducing lifting by fixing the direction change portion is particularly high. In addition, there is a high degree of freedom in the arrangement of metal parts.

[0020] (6) In any one of the above (1) to (5), the resin part is formed of a fiber-reinforced composite material, A fiber volume fraction Vfa of the uneven thickness portion may be smaller than a fiber volume fraction Vfb of the thin thickness portion.

[0021] The insert molded article according to this embodiment can be manufactured by a simple method, since a flat plate-shaped resin material can be used before molding.

[0022] (7) In any one of the above (1) to (6), the resin part is formed of a fiber-reinforced composite material, the resin part has a first resin layer and a second resin layer disposed closer to the metal part than the first resin layer, The fiber volume fraction Vf1 of the first resin layer may be greater than the fiber volume fraction Vf2 of the second resin layer.

[0023] Insert-molded products having uneven thickness portions and thin-walled portions are prone to warping during cooling in the molding process. On the other hand, when an insert molded body has resin layers with different fiber volume fractions, the shrinkage rate differs depending on the fiber volume fraction, and the difference in the shrinkage rate of each resin layer causes a warping force during cooling. In the insert molded body according to this embodiment, by laminating the first resin layer and the second resin layer with different shrinkage rates in a predetermined order, the warping caused by the shape and the warping caused by the difference in the shrinkage rate of the resin layers can be offset, thereby suppressing warping overall.

[0024] (8) In any one of the above (1) to (7), the resin part is formed of a fiber-reinforced composite material, The reinforcing fibers contained in the resin part may have a weight average fiber length of 100 mm or less.

[0025] In the insert molded article according to this embodiment, the length of the fibers contained in the resin part is short, which can reduce warping of the resin part that occurs during cooling in the molding process.

[0026] (9) In the above (2) or (3), when the direction perpendicular to the outer surface of the resin part is defined as the thickness direction, the difference in thickness between the uneven thickness portion and the thin-walled portion may be equal to or greater than the thickness of the metal part.

[0027] When at least a portion of the metal part is arranged along the thin-walled portion, in the insert molding of this embodiment, if the difference in thickness between the uneven thickness portion and the thin-walled portion is equal to or greater than the thickness of the metal part, the metal part arranged in the molded product is less likely to shift. When at least a part of the metal component is arranged along the uneven wall portion, in the insert molded body according to the present embodiment, since the depth of the groove provided in the mold for forming the uneven wall portion is twice or more the thickness of the metal component, the positioning of the metal component is easy and molding is easy. As described above, for example, when the metal component is arranged along the concave portion (groove portion) of the lower mold during insert molding and then the resin material is laminated from above and press molded, when it becomes an insert molded body, the metal component is arranged along the top of the uneven wall portion (protrusion). At this time, if it is designed so that the difference in thickness between the uneven wall portion and the thin wall portion is equal to or greater than the thickness of the metal component, the metal component is less likely to shift from the concave portion (groove portion) of the lower mold during molding.

[0028] (10) In any of (1) to (9) above, in a cross-sectional view perpendicular to the outer surface of the resin component, the uneven wall portion and the thin wall portion may be alternately positioned.

[0029] According to the insert molded body according to the present embodiment, the metal component can be arranged on the resin component without deviation.

[0030] (11) In (10) above, at least a part of the metal component is arranged along the uneven wall portion or the thin wall portion, and the relationship between the flatness Fa of the resin component and the difference h in thickness between the uneven wall portion and the thin wall portion may be 0 < Fa / h < 1.3.

[0031] According to the insert molded body according to the present embodiment, the lifting of the metal component from the resin component can be further reduced, and it becomes easy to combine with other components.

[0032] A battery tray or a protective cover for a battery tray according to an embodiment of the present disclosure (12) includes the insert molded body according to any of (1) to (11) above, and the metal component is an electric circuit for impact detection.

[0033] According to the battery tray or the protective cover for a battery tray according to the present embodiment, it is possible to prevent ignition of the battery by detecting an impact.

[0034] The inverter box according to an embodiment of the present disclosure is (13) including the insert molded body according to any one of (1) to (11) above, wherein the metal part is an electric circuit.

[0035] In the inverter box according to this embodiment, the electric circuit and the resin part are fixed, and the lifting of the electric circuit is reduced.

[0036] A method for manufacturing an insert molded body according to an embodiment of the present disclosure is (14) A method for manufacturing an insert molded body having a resin part and a metal part, wherein the resin part has a thick-walled part and a thin-walled part thinner than the thick-walled part, and at least a part of the metal part is disposed on the outer surface of the resin part along the thick-walled part or the thin-walled part. The metal part has a turning part whose extending direction on the outer surface is changed, and the method includes a step of fixing the resin part and the metal part to each other at the turning part.

[0037] According to the method for manufacturing an insert molded body according to this embodiment, by fixing the turning part of the metal part, an insert molded body with reduced lifting of the metal part can be provided.

[0038] (15) In the above (14), the insert molded body further has a sealing layer for sealing the metal part. The method may include a step of molding the sealing layer together with the resin part and the metal part.

[0039] According to the method for manufacturing an insert molded body according to this embodiment, protection and insulation of the insert molded body can be provided without requiring a separate process.

[0040] Hereinafter, an insert molded article and a method for manufacturing an insert molded article according to an embodiment of the present disclosure will be described with reference to the drawings, but the present invention is not limited to these examples. The dimensions and positions of each component in the drawings are schematic and are not intended to limit the dimensions and positions of the components in an actual product.

[0041] [Insert molding] FIG. 1 is a plan view showing an insert-molded body 1 according to a first embodiment of the present disclosure. The insert-molded body 1 according to this embodiment can be used, for example, as an impact detection sensor to be placed on the bottom of a vehicle. As shown in FIG. 1, the insert-molded body 1 includes a resin part 10 and a metal part 20, and the metal part 20 is placed on the outer surface of the resin part 10. FIG. 2 is a cross-sectional view taken along line AA in FIG. 1. FIG. 3 is a cross-sectional view taken along line BB in FIG. 1.

[0042] (plastic parts) The resin part 10 has a generally flat plate shape. As shown in FIG. 2, the resin part 10 has a thickness deviation portion 11 and a thin-walled portion 12 that is thinner than the thickness deviation portion 11. One main surface of the resin part 10 (the upper surface in FIG. 2) has a convex portion corresponding to the thickness deviation portion 11, and the other main surface (the lower surface in FIG. 2) is flat. In the present disclosure, the thickness deviation portion 11 refers to a portion that varies in thickness relative to the entire resin part 10, and the thickness deviation portion 11 itself may be uniform in thickness. When the metal part 20 is arranged along the thickness deviation portion 11, it is preferable that the outer surface of the thickness deviation portion 11 on which the metal part 20 is arranged is flat.

[0043] The resin material that constitutes the resin part 10 is not particularly limited, and various raw materials can be appropriately selected depending on the application of the insert-molded article 1. For example, if the insert-molded article 1 is a vehicle part, the resin part 10 may be made of a fiber-reinforced composite material from the viewpoint of improving strength and reducing weight. Either carbon fiber or glass fiber may be used as the reinforcing fiber, or both may be used in combination. Either a thermosetting resin or a thermoplastic resin may be used as the resin, and it is preferable to use a thermoplastic resin.

[0044] Examples of thermoplastic resins include vinyl chloride resins, vinylidene chloride resins, vinyl acetate resins, polyvinyl alcohol resins, polystyrene resins, acrylonitrile-styrene resins (AS resins), acrylonitrile-butadiene-styrene resins (ABS resins), acrylic resins, methacrylic resins, polyethylene resins, polypropylene resins, various thermoplastic polyamide resins, polyacetal resins, polycarbonate resins, polyethylene terephthalate resins, polyethylene naphthalate resins, polybutylene naphthalate resins, polybutylene terephthalate resins, polyarylate resins, polyphenylene ether resins, polyphenylene sulfide resins, polysulfone resins, polyether sulfone resins, polyether ether ketone resins, and polylactic acid resins.

[0045] The thermoplastic resin may be a crystalline resin or an amorphous resin. In the case of a crystalline resin, specific examples of preferred crystalline resins include polyamide resins such as nylon 6, polyethylene terephthalate resins, polybutylene terephthalate resins, polyethylene resins, polypropylene resins, polyacetal resins, and polyphenylene sulfide resins. Among these, polyamide resins, polybutylene terephthalate resins, and polyphenylene sulfide resins are preferably used because of their excellent heat resistance and mechanical strength.

[0046] The thickness of the resin part 10 is not particularly limited, but is, for example, 0.5 mm to 10.0 mm, and preferably 1.0 mm to 8.0 mm. The thickness of the resin part 10 here is the thickness of the thickest part, more specifically, the maximum thickness of the uneven thickness portion 11.

[0047] (metal parts) The metal component 20 is a metal plate disposed on the outer surface of the resin component 10. As shown in FIG. 1, the metal component 20 is arranged in a bellows shape on the main surface of the resin component 10 and is configured to widely cover the main surface of the resin component 10. At least a part of the metal component 20 is disposed on the outer surface of the resin component 10 along the uneven wall portion 11 or the thin wall portion 12. In the insert molded body 1 of FIG. 1, the metal component 20 is disposed along the uneven wall portion 11 of the resin component 10, more specifically, on the uneven wall portion 11.

[0048] As shown in FIG. 1, the metal component 20 has a turning portion 23 in which the extending direction on the outer surface is changed. More specifically, the metal component 20 has a first portion 21 extending in the vertical direction of the paper surface (hereinafter referred to as the first in-plane direction) and a second portion 22 extending in the left-right direction of the paper surface (hereinafter referred to as the second in-plane direction), and the first portion 21 and the second portion 22 are connected at the turning portion 23. In the present embodiment, a rectangular range in which the extended portion of the first portion 21 and the extended portion of the second portion 22 overlap can be regarded as the turning portion 23.

[0049] The metal material constituting the metal component 20 is not particularly limited, and various metals or alloys can be used according to the required characteristics. Examples of the metal material include copper, aluminum, iron, chromium, nickel, manganese, or alloys thereof.

[0050] The shape of the metal component 20 is not limited to a plate shape and can be appropriately changed according to the use and configuration. Specifically, the metal component 20 may be a metal wire having a substantially circular cross section, or may be a bundle of laminated or integrated metal wires.

[0051] The thickness of the metal component 20 is not particularly limited and can be appropriately changed according to the use and configuration. The thickness of the metal component 20 may be, for example, 0.01 mm to 10 mm, may be 0.05 mm to 1.0 mm, or may be 0.10 mm to 0.50 mm. When the metal component 20 is a metal wire, the maximum diameter along the thickness direction in the cross section of the metal wire is regarded as the thickness.

[0052] (Adhesion between resin part and metal part) The resin part 10 and the metal part 20 are adhered to each other at the deflecting portion 23 of the metal part 20. Specifically, the insert molded body 1 has a caulking portion 30 that adheres the resin part 10 and the metal part 20 at the deflecting portion 23 of the metal part 20. FIG. 3 is a cross-sectional view taken along the line B-B in FIG. 1, showing how the resin part 10 and the metal part 20 are adhered by the caulking portion 30. A hole is provided in the metal part 20 at a position corresponding to the caulking portion 30. The caulking portion 30 is formed by extruding the resin material from the hole provided in the metal part 20 during compression molding. Therefore, the caulking portion 30 is made of the same resin material as the resin part 10.

[0053] Since the insert molded body 1 is heated during molding and then cooled to room temperature, each component constituting the insert molded body 1 shrinks during cooling. In the case of the insert molded body 1 having the resin part 10 and the metal part 20, generally, the coefficient of thermal expansion of the metal part 20 is larger than that of the resin part 10, so the metal part 20 shrinks more significantly than the resin part 10. In particular, in the deflecting portion 23 of the metal part 20 where the extending direction is changed, a force that shrinks in different vectors is generated during contraction. As a result, the deflecting portion 23 of the metal part 20 is particularly likely to lift off from the resin part 10.

[0054] In the insert molded body 1 according to the present embodiment, the resin part 10 and the metal part 20 are adhered to each other by the caulking portion 30 at the deflecting portion 23 that is likely to lift off. Thereby, the lifting of the metal part 20 can be reduced.

[0055] (Reduction of lifting due to warping of resin part) When at least a part of the metal part 20 is arranged along the uneven thickness portion 11 or the thin thickness portion 12, and in a cross-sectional view perpendicular to the outer surface of the resin part 10, the uneven thickness portion 11 and the thin thickness portion 12 are alternately positioned, it is preferable that the relationship between the flatness Fa of the resin part 10 and the thickness difference h between the uneven thickness portion 11 and the thin thickness portion 12 is 0 < Fa / h < 1.3. The flatness Fa is defined by the following steps 1 to 5. (Step 1) The resin component 10 is placed stationary such that the surface of the uneven thickness portion 11 where the metal component 20 is to be disposed (hereinafter sometimes simply referred to as the "disposal surface") faces downward. (Step 2) Observe the cross-section of the resin component 10 in a cross-sectional view where the uneven thickness portion 11 and the thin thickness portion 12 are alternately positioned. Cut out the observation range of the resin component 10 such that the length Ly along the direction in which the uneven thickness portion 11 and the thin thickness portion 12 are alternately positioned becomes 40 cm. (Step 3) Pay attention to the disposal surface of the uneven thickness portion 11 or the thin thickness portion 12 where the metal component 20 is to be disposed. (Step 4) Draw two parallel ideal straight lines with the minimum necessary vertical width so as to include all of the disposal surfaces. (Step 5) Define the distance between the two ideal straight lines drawn in Step 4 as the flatness Fa. Steps 1 to 5 will be described with reference to FIGS. 9A and 9B. Note that FIGS. 9A, 9B, and 10 are drawn on the premise that the metal component 20 is disposed on the uneven thickness portion 11. FIG. 9A shows the resin component 10 placed stationary such that the disposal surface of the uneven thickness portion 11 faces downward. The uneven thickness portion 11 and the thin thickness portion 12 are alternately positioned along the Y-axis direction in FIG. 9A. The Z-axis direction is the thickness direction of the resin component 10. FIG. 9A is a view of observing a cross-section by the Y-Z plane after cutting out the observation range of the resin component 10 such that the length Ly along the Y-axis direction becomes 40 cm (Step 2). The disposal surface of the uneven thickness portion 11 where the metal component 20 is to be disposed is the region shown by 902 in FIG. 9B (Step 3). The two parallel ideal straight lines are exemplified by 901 in FIG. 9A. The two parallel ideal straight lines 901 are drawn such that the distance therebetween is minimized. In other words, the two parallel ideal straight lines 901 are drawn with the minimum necessary vertical width. Note that in the present disclosure, a method of observing and measuring by reversing the top and bottom of the molded body in FIG. 9A and in a state where the surface of the thin thickness portion 12 is in contact with the table is not adopted. When the flatness Fa varies depending on the observation range, if there is a portion satisfying 0 < Fa / h < 1.3 even at one location, it is regarded that 0 < Fa / h < 1.3 is satisfied on the disposal surface of the uneven thickness portion 11.

[0056] The difference h in thickness between the uneven thickness portion 11 and the thin thickness portion 12 refers to the depth of the groove when observing a cross section in which the uneven thickness portion 11 and the thin thickness portion 12 are alternately located, as exemplified in Figure 10. When the height h of the resin part 10 varies depending on the measurement position, if h at at least one measurement position is 0 <Fa / h<1.3を満たしていれば、偏肉部11の配置面において0<Fa / h<1.3が満たされているとみなす。

[0057] When Fa / h=0, the surface of the uneven thickness portion 11 on which the metal part 20 is placed is a completely flat plane, that is, an ideal plane. <Fa / hを満たす場合、樹脂部品10が金属部品20に向かって凸となるように反っていることを意味する。0<Fa / hであれば、金属部品20を樹脂部品10の平面方向(図9AのY方向)に向かって引っ張ることができ、樹脂部品10からの金属部品20の浮き上がりをさらに低減できる。 If Fa / h<1.3, it is easy to combine with other parts, for example, to assemble an automobile. <Fa / h≦1.0であり、更に好ましくは0<Fa / h≦0.7であり、より一層好ましくは0<Fa / h≦0.4であり、最も好ましくは0<Fa / h≦0.1である。 A preferred value of Fa is 0 mm or more and less than 30 mm, more preferably more than 0 mm and less than 20 mm, even more preferably more than 0 mm and less than 15 mm, even more preferably more than 0 mm and less than 10 mm, and most preferably more than 0 mm and less than 5 mm. A preferred value of h is greater than 0 mm and less than 30 mm, more preferably greater than 0 mm and less than 20 mm, even more preferably greater than 0 mm and less than 15 mm, even more preferably greater than 0 mm and less than 10 mm, and most preferably greater than 0 mm and less than 5 mm.

[0058] In addition, in the insert molded body 1 according to the present embodiment, the metal part 20 is arranged along the thick-walled part 11. The insert molded body 1 having such a configuration can be manufactured by arranging the metal part 20 in a groove provided in the mold 40 and performing molding. Since the metal part 20 is arranged in the groove of the mold 40, the positioning of the metal part 20 becomes easy and it is easy to perform molding. Note that it is not necessary for the entire metal part 20 to be arranged along the thick-walled part 11, and positioning becomes easy as long as at least a part of the metal part 20 is arranged along the thick-walled part 11.

[0059] Further, in the insert molded body 1 according to the present embodiment, the first in-plane direction and the second in-plane direction in the metal part 20 are perpendicular to each other. When the first in-plane direction and the second in-plane direction in the metal part 20 are perpendicular to each other, the turning part 23 connecting the first part 21 and the second part 22 is particularly likely to float. Therefore, by fixing the resin part 10 and the metal part 20 at the turning part 23, the floating of the metal part 20 can be effectively reduced. In addition, when it is desired to widely cover the outer surface of the resin part 10 with the metal part 20, the degree of freedom in arranging the metal part 20 can be increased because the first in-plane direction and the second in-plane direction are perpendicular to each other.

[0060] When the resin part 10 is formed of a fiber-reinforced composite material, it is preferable that the fiber volume ratio Vfa of the thick-walled part 11 is smaller than the fiber volume ratio Vfb of the thin-walled part 12. In this case, a resin material having both main surfaces flat (so-called plate-shaped resin material) can be used as the resin material placed on the mold 40, and it can be manufactured by a simple method. The specific explanation is as follows. When the resin material placed on the mold 40 is a resin material having both main surfaces flat (so-called plate-shaped resin material), the thin-walled part 12 is compressed by the mold 40 during molding. At this time, the resin component in the thin-walled part 12 flows toward the thick-walled part 11, while the fibers contained in the resin material remain in the thin-walled part 12. As a result, the fiber volume ratio Vfa of the thick-walled part 11 becomes smaller than the fiber volume ratio Vfb of the thin-walled part 12.

[0061] The fiber volume ratio Vfa of the thick meat part 11 is, for example, 25 to 45%, preferably 30 to 40%. The fiber volume ratio Vfb of the thin meat part 12 is, for example, 30 to 50%, preferably 35 to 45%. The difference (Vfb - Vfa) between the fiber volume ratio Vfa of the thick meat part 11 and the fiber volume ratio Vfb of the thin meat part 12 is, for example, 1 to 15%, preferably 3 to 12%.

[0062] When the resin part is formed of a fiber-reinforced composite material, the resin part 10 has a first resin layer 13 and a second resin layer 14 disposed closer to the metal part 20 side than the first resin layer 13, and it is preferable that the fiber volume ratio Vf1 of the first resin layer 13 is larger than the fiber volume ratio Vf2 of the second resin layer 14. By having the first resin layer 13 and the second resin layer 14 in which the resin part 10 satisfies the above relationship of the fiber volume ratio, warping of the resin part 10 can be suppressed. The reason will be described below.

[0063] FIG. 4 is an enlarged cross-sectional view of a part of a resin component 110 that does not have resin layers (i.e., resin layers corresponding to the first resin layer 13 and the second resin layer 14) with different fiber volume ratios. The resin component 110 is a component formed by compressing a plate-shaped resin material in a mold so as to provide a thick-walled portion 111 and a thin-walled portion 112. As shown in FIG. 4, the resin component 110 has regions 110A (region A), 110B (region B), and 110C (region C) where the fiber orientation and fiber volume ratio are different from each other. Region A is the region above the thick-walled portion 111 and is the portion that protrudes upward in a cross-sectional view. Region B is the region corresponding to the thin-walled portion 112. Region C is the region below the thick-walled portion 111 and is the portion located below region A. The differences in fiber orientation and fiber volume ratio in each region are caused by the fact that due to the uneven shape of the resin component 110, the way the fibers flow during compression molding is different for each region. The plurality of broken lines F in FIG. 4 are lines that schematically indicate the orientation and density of the fibers in each region. Note that the broken lines F are attached for convenience in explanation and do not indicate the exact position, orientation, density, etc. of the fibers contained in the resin component 110. As shown in FIG. 4, since the fiber orientation along the thickness direction in region A is relatively strong, region A hardly shrinks even when cooled. Region B has a high fiber volume ratio and a small linear expansion coefficient, so the amount of shrinkage during cooling is small. Region C has a low fiber volume ratio and a large linear expansion coefficient, so it is most likely to shrink during cooling. Since there is a difference in the shrinkage rate during cooling among regions A to C in this way, the insert molded body 1 in the case of not having resin layers with different fiber volume ratios and having uneven shapes such as the thick-walled portion 11 and the thin-walled portion 12 is likely to warp during cooling in the molding process.

[0064] FIG. 5 is a cross-sectional view for explaining the first resin layer 13 and the second resin layer 14. When the insert molded body 1 has resin layers with different fiber volume ratios, a warping force is generated during cooling due to the difference in the shrinkage rate of each resin layer. When the first resin layer 13 and the second resin layer 14 are laminated as shown in FIG. 5 and the fiber volume ratio Vf1 of the first resin layer 13 is larger than the fiber volume ratio Vf2 of the second resin layer 14, it is possible to offset the warping caused by the different fiber orientations in regions A to C of FIG. 4 and the warping caused by the difference in the shrinkage rate of the resin layers. As a result, warping can be suppressed as a whole.

[0065] The fiber volume ratio Vf1 of the first resin layer 13 is, for example, 25 to 45%, preferably 30 to 40%. The fiber volume ratio Vf2 of the second resin layer 14 is, for example, 15 to 35%, preferably 20 to 30%. The difference (Vf1 - Vf2) between the fiber volume ratio Vf1 of the first resin layer 13 and the fiber volume ratio Vf2 of the second resin layer 14 is, for example, 3 to 20%, preferably 5 to 15%.

[0066] The fiber volume ratio of the resin component 10 can be determined, for example, by the following method. Cut out a 100 mm × 100 mm sample from the resin component 10, (i) Measure the weight of the resin component. (ii) Heat in an electric furnace (FP410 manufactured by Yamato Scientific Co., Ltd.) heated to 550°C under a nitrogen atmosphere for 4 hours to burn off organic substances such as the matrix resin, and measure the weight. (i) - (ii) Calculate the weights of the resin and the reinforcing fiber by weighing. Next, using the specific gravity of each component, calculate the fiber volume ratio from the following formula (1). Fiber volume ratio = 100 × reinforcing fiber volume / (reinforcing fiber volume + resin volume) (1)

[0067] When the resin component 10 is formed of a fiber-reinforced composite material, the weight average fiber length of the reinforcing fiber contained in the resin component 10 is preferably 100 mm or less. When the weight average fiber length is 100 mm or less, the warp of the insert molded body 1 having the thick portion 11 and the thin portion 12 can be reduced. The weight average fiber length of the reinforcing fiber contained in the resin component 10 is preferably 50 mm or less, more preferably 30 mm or less, and still more preferably 20 mm or less. The lower limit of the weight average fiber length is not particularly limited, but is, for example, 1 mm or more.

[0068] The weight average fiber length of the reinforcing fibers contained in the resin component 10 is determined, for example, by the following method. The fiber lengths of 100 fibers randomly extracted from the resin component 10 are measured in 1 mm units using a caliper or the like. When the fiber length of each reinforcing fiber is Li and the number of measurements is j, the weight average fiber length (Lw) is determined by the following formula (a).

[0069]

Equation

[0070] In the insert molded body 1 according to the present disclosure, when the direction perpendicular to the outer surface of the resin component 10 is defined as the thickness direction, it is preferable that the difference in thickness between the thick-walled portion 11 and the thin-walled portion 12 is equal to or greater than the thickness of the metal component 20. When the difference in thickness between the thick-walled portion 11 and the thin-walled portion 12 is equal to or greater than the thickness of the metal component 20, the depth of the groove provided in the mold 40 to form the thick-walled portion 11 becomes twice or more the thickness of the metal component 20, so that the positioning of the metal component 20 is easy and molding is easy. When the metal components 20 are laminated or integrated, the above-described effect can be obtained if the difference in thickness between the thick-walled portion 11 and the thin-walled portion 12 is equal to or greater than the thickness of each metal component 20, but more preferably, it is equal to or greater than the total thickness of the laminated or integrated metal components 20.

[0071] In the insert molded body 1 according to the present disclosure, in a cross-sectional view perpendicular to the outer surface of the resin part 10, it is preferable that the thick-walled part 11 and the thin-walled part 12 are alternately positioned. As shown in FIG. 2, in the insert molded body 1 according to the present embodiment, the thick-walled part 11 and the thin-walled part 12 are alternately positioned in a cross-sectional view perpendicular to the outer surface of the resin part 10. Since the metal part 20 is arranged along the thick-walled part 11 or the thin-walled part 12, by having such a configuration, the metal part 20 can be arranged on the resin part 10 without bias. Note that the "cross-section perpendicular to the outer surface of the resin part 10" is not uniquely determined, but when the thick-walled part 11 and the thin-walled part 12 are alternately positioned in any cross-sectional view perpendicular to the outer surface of the resin part 10, it is regarded as "in a cross-sectional view perpendicular to the outer surface of the resin part 10, the thick-walled part 11 and the thin-walled part 12 are alternately positioned". It is more preferable that the thick-walled part 11 and the thin-walled part 12 are alternately positioned in all cross-sectional views perpendicular to the outer surface passing through the center of gravity of the resin part 10.

[0072] Further, in the insert molded body of the present disclosure, the metal part may be arranged along the thin-walled part instead of the thick-walled part, and for such a configuration, the aspect shown in FIG. 12 described later can be referred to. The insert molded body having such a configuration can be manufactured, for example, by arranging a metal material in a convex part instead of a concave part in the mold 40 shown in FIG. 6 and performing molding. Note that it is not necessary for the entire metal part to be arranged along the thin-walled part, and as long as at least a part of the metal part is arranged along the thin-walled part, the position of the metal part in the molded product is less likely to shift.

[0073] (Impact detection sensor) The battery tray or the protective cover of the battery tray in the present disclosure includes the insert molded body of the present disclosure. In the battery tray or the protective cover of the battery tray including the insert molded body of the present disclosure, the metal part is, for example, an electric circuit for impact detection. FIG. 11 shows an example of the protective cover 1102 of the battery tray mounted on the vehicle 1101. The protective cover 1102 of the battery tray includes an electric circuit 1103 for impact detection.

[0074] The battery mounted on an electric vehicle is heavy and is placed under the vehicle floor protected by the vehicle structure in order to achieve a low center of gravity. During high-speed driving, there is a possibility that the battery mounted on the vehicle may be damaged by flying stones or the like, and at low speeds, it may come into contact with the ground during parking operation and cause damage. Therefore, the battery tray of the electric vehicle may be made robust, or a battery tray protection cover may be attached under the battery tray to protect the battery box from below. In this case, when receiving an impact, conventionally, it was the driver who determined whether the vehicle needed to be inspected at a repair shop. However, since the underside of the vehicle is difficult to see and a professional's eye is required to accurately determine the damage, it was difficult to estimate the exact degree of impact. Therefore, by using the metal part as an electric circuit for impact detection in the present disclosure, an impact can be detected, the degree of the impact can be classified, and when it is completely destroyed, the driver can be warned. As a result, it is possible to prevent holes from forming in the battery tray or the protection cover of the battery tray and prevent the battery from catching fire. Furthermore, the damaged area can be more specifically identified by the electric circuit, and the cells in the damaged area can be emptied in battery management to prevent the risk of fire.

[0075] (Inverter box) The inverter box in the present disclosure includes the insert molded body of the present disclosure. In the inverter box including the insert molded body of the present disclosure, the metal part is, for example, an electric circuit. An inverter is a device that converts direct current (DC) supplied from a battery into alternating current (AC), and an inverter box is a box for storing the inverter. In the inverter box of the present disclosure, the current circuit is insert molded in the thin part (recessed part), and it is preferable to arrange a metal part here and fix it to the resin part. A cross-sectional view of the insert molded body 1201 used for the inverter box is illustrated in FIG. 12. The insert molded body 1201 has a thick part 1203 and a thin part 1204 made of resin, and the electric circuit 1202 is embedded in the thin part 1204 (recessed part).

[0076] [Method for manufacturing insert molded body] Next, a method for manufacturing the insert molded body 1 according to an embodiment of the present disclosure will be described. FIG. 6 is a diagram showing a mold 40 for producing the insert molded body 1. The mold 40 is composed of an upper mold 41 and a lower mold 42.

[0077] FIG. 6 depicts an example of a mold when manufacturing the insert molded body 1 in which at least a part of the metal part is arranged along the uneven wall part. As shown in FIG. 6, a groove is provided in the lower mold 42, and the metal material 50 is placed so as to fit into the groove of the lower mold 42. The metal material 50 typically has the same shape as the metal part 20 after molding. That is, the metal material 50 has a turning part 23, and a hole for forming the caulking part 30 is provided in the turning part 23. Next, a flat-plate-shaped thermoplastic resin material (not shown) is placed between the upper mold 41 and the lower mold 42, and then the mold 40 is heated to 150° C., the mold 40 is closed, and compression molding is performed. In this compression molding process, the resin material flows into the groove of the lower mold 42 to form the uneven wall part 11. Also, the resin material is extruded from the hole provided in the turning part 23 of the metal material 50 to form the caulking part 30. Then, by cooling the mold 40 to room temperature, an insert molded body 1 in which the metal part 20 and the resin part 10 are integrated is obtained. At this time, the metal part 20 and the resin part 10 are fixed to each other by the formed caulking part 30.

[0078] The insert molded body 1 thus formed has a resin part 10 and a metal part 20. The resin part 10 has an uneven wall part 11 and a thin wall part 12 thinner than the uneven wall part 11. The metal part 20 has at least a part arranged on the outer surface of the resin part 10 along the uneven wall part 11 or the thin wall part 12, and the metal part 20 has a turning part 23 whose extending direction on the outer surface is changed. Although the resin part 10 is located above the metal part 20, if the top and bottom of the obtained molded body are reversed, it coincides with the configuration of the insert molded body 1 shown in FIG. 2. Regarding the detailed configuration of the insert molded body 1, the above description is incorporated by reference, and overlapping content is omitted.

[0079] The manufacturing method of the insert molded body 1 of the present disclosure includes a step of fixing the resin part 10 and the metal part 20 to each other at the deflecting part 23. The specific embodiment of the fixing step is not particularly limited, as long as it can reduce the lifting of the metal part 20 from the resin part 10 at the deflecting part 23. As in the above-described embodiment, it is preferable to fix the resin part 10 and the metal part 20 at the deflecting part 23 simultaneously with the molding of the insert molded body 1.

[0080] In the manufacturing method of the insert molded body 1, the insert molded body 1 further has a sealing layer for sealing the metal part 20, and it is preferable that the above manufacturing method includes a step of molding the sealing layer together with the resin part 10 and the metal part 20. For example, as shown in FIG. 6, by placing the sealing material 60, which is the material of the sealing layer, together with the metal material 50 and performing molding, the sealing layer can be molded together with the resin part 10 and the metal part 20. Thereby, the protection and insulation of the insert molded body 1 by the sealing layer can be provided without going through a separate process. The sealing layer may serve as a sealing agent for the metal material, and for example, it may be a layer for the purpose of electrical insulation, corrosion prevention due to contact with water, gas, etc., and prevention of breakage due to vibration. The material of the sealing layer is not particularly limited, and various materials such as metals such as iron, metal oxides, inorganic materials such as silica, inorganic mineral particles, and resin compositions can be used according to the purpose. Also, it may optionally contain various stabilizers, absorbents, etc. as organic substances, and non-conductive metal bodies such as iron oxide, using epoxy resin, silicone resin, or thermoplastic resin as the matrix resin. Note that although FIG. 6 shows a mode of placing the sealing material 60 together with the metal material 50 on the lower mold 42, the manufacturing method of the insert molded body 1 having a sealing layer is not limited to this mode. The method of molding the sealing layer may be injection molding or compression molding, and can be appropriately selected according to the manufacturing equipment, the shape and material of the sealing layer, etc. Also, although FIG. 6 shows an example of a method for manufacturing an insert molded body having a sealing layer, the manufacturing method of the insert molded body of the present disclosure is also applicable to an insert molded body without a sealing layer. That is, the sealing material 60 is not essential.

[0081] When the sealing layer is formed by injection molding, for example, a supply path for supplying the injection material is provided in the lower mold 42. By injecting the injection material into the mold during insert molding, an insert-molded body 1 having the sealing layer can be obtained.

[0082] When the insert-molded body 1 is formed by compression molding, the charge rate of the resin material is preferably 90% or higher, more preferably 95% or higher, and even more preferably 99% or higher. There is no upper limit to the charge rate, and it may exceed 100%, but to reduce material waste, it is preferably 100% or lower. The charge rate of the resin material during compression molding is the ratio (A2 / A1) of the area A2 of the resin material placed in the mold 40 before molding to the area A1 of the insert-molded body 1 in a plan view. A high charge rate suppresses the in-plane flow of the matrix resin, thereby reducing unevenness in the fiber content of the resin part 10 after molding. This improves the processability of the insert-molded body 1.

[0083] Although the present disclosure has been described above in accordance with specific embodiments, the present disclosure is not limited to these embodiments.

[0084] Another aspect of the turning portion 23 of the metal part 20 will be described with reference to the drawings. FIG. 7 is a diagram showing an insert-molded body 1 according to a second embodiment of the present disclosure. In the insert-molded body 1 shown in FIG. 7, the metal part 20 has a first portion 21 extending in the up-down direction of the page and a second portion 22 extending in the left-right direction of the page, and the first portion 21 and the second portion 22 are connected by a turning portion 23 extending in a direction that differs by 45 degrees from each other. In the first embodiment, the first portion 21 and the second portion 22 are directly connected to each other and perpendicular to each other. However, in the second embodiment, the first portion 21 and the second portion 22 do not directly intersect but are indirectly connected via the turning portion 23. In this embodiment, the entire portion extending in a direction that differs by 45 degrees from each other can be considered to be the turning portion 23.

[0085] FIG. 8 is a view showing the insert molded body 1 according to the third embodiment of the present disclosure. In the insert molded body 1 shown in FIG. 8, the metal part 20 has a first part 21 extending in the vertical direction of the paper surface and a second part 22 extending in the left-right direction of the paper surface, and the first part 21 and the second part 22 are connected by a quarter-arc-shaped part 231. In this case, the entire quarter-arc-shaped part 231 can be regarded as a turning part. That is, not only a shape that linearly extends like the turning parts of the first and second embodiments, but also a shape that continuously changes the direction like in this embodiment, the entire part where the direction changes can be regarded as the turning part 23. In this embodiment, the first part 21 and another first part 21 extending parallel to the first part 21 are connected by a semi-arc-shaped part 232. In this case, the entire semi-arc-shaped part 232 can also be regarded as the turning part 23.

[0086] Further, in the insert molded body 1 according to the above embodiment, the resin part 10 and the metal part 20 are fixed by the caulking part 30 formed of a resin material, but it is not limited to this mode. For example, after the insert molded body 1 is taken out of the mold 40, the resin part 10 and the metal part 20 may be fixed at the turning part 23. As a fixing method, it may be mechanically fixed by bolts, rivets, etc., or an adhesive may be used. However, from the viewpoint of manufacturing efficiency, it is preferable to perform the fixing during the molding process.

[0087] In addition, in the insert molded body 1 according to the above-described embodiment, the first in-plane direction and the second in-plane direction were perpendicular to each other. However, as long as the first in-plane direction and the second in-plane direction extend in different directions from each other, they do not have to be perpendicular. The angle formed by the first in-plane direction and the second in-plane direction is preferably 10 degrees or more and 170 degrees or less, more preferably 20 degrees or more and 160 degrees or less, and even more preferably 45 degrees or more and 135 degrees or less. The angle formed by the first in-plane direction and the second in-plane direction here refers to the angle formed by a vector starting from the turning portion 23 and directed toward the first portion 21 and a vector starting from the turning portion 23 and directed toward the second portion 22 in the first portion 21 and the second portion 22 connected to each other by the turning portion 23. The angle formed by the first in-plane direction and the second in-plane direction is defined within the range of 0 degrees or more and 180 degrees or less.

[0088] In the description of the insert molded body 1 according to the above-described embodiment, the positions of the first portion 21 and the second portion 22 were specified with reference to the drawings. However, the first portion 21 and the second portion 22 can be set at any portion where the metal part 20 extends. That is, the first portion 21 and the second portion 22 shown in the drawings are merely examples, and it is also possible to set other portions as the first portion 21 or the second portion 22. Along with this, the first in-plane direction and the second in-plane direction can also be set in any direction in which the metal part 20 extends. If the angle formed in at least one of the combinations of the first in-plane direction and the second in-plane direction that can be set is within the above range, it can be said that "the angle formed by the first in-plane direction and the second in-plane direction is within the said range".

[0089] In addition, in the manufacturing method of the insert molded body 1 according to the above-described embodiment, the mode of compression molding the resin material was described. However, it may be formed by other molding methods such as injection molding. As long as it is a molding method that heats to a temperature higher than normal temperature during molding, the effects of the present disclosure can be obtained.

Industrial Applicability

[0090] The insert molded body and the method for manufacturing the insert molded body of the present disclosure are applicable to parts of various moving bodies, industrial machines, etc., and can be applied to, for example, vehicle impact detection sensors, coils, planar heating elements, etc.

Explanation of Signs

[0091] 1, 1201: Insert molded body 10: Resin part 11, 1203: Thick-walled part 12, 1204: Thin-walled part 13: First resin layer 14: Second resin layer 20, 1202: Metal part 21: First part 22: Second part 23: Deflection part 30: Crimp part 40: Mold 41: Upper mold 42: Lower mold 50: Metal material 60: Sealing material 110: Resin part 110A: Region A 110B: Region B 110C: Region C 111: Thick-walled part 112: Thin-walled part 901: Two parallel ideal straight lines 902: Arrangement surface of the thick-walled part 11 where the metal part 20 is arranged 1101: Vehicle 1102: Protection cover of battery tray 1103: Electric circuit for impact detection

Claims

1. An insert-molded body having a resin part and a metal part, wherein the resin part has a thick-walled part and a thin-walled part thinner than the thick-walled part, at least a part of the metal part is disposed on the outer surface of the resin part along the thick-walled part or the thin-walled part, the metal part has a turning part whose extending direction on the outer surface is changed, and the resin part and the metal part are fixed to each other at the turning part. An insert-molded body.

2. The insert-molded body according to claim 1, wherein at least a part of the metal part is disposed along the thin-walled part.

3. The insert-molded body according to claim 1, wherein at least a part of the metal part is disposed along the thick-walled part.

4. The metal part has a first part extending in a first in-plane direction and a second part extending in a second in-plane direction different from the first in-plane direction, and the turning part connects the first part and the second part. The insert-molded body according to any one of claims 1 to 3.

5. The insert-molded body according to claim 4, wherein the first in-plane direction and the second in-plane direction are perpendicular to each other.

6. The resin part is formed of a fiber-reinforced composite material, and the fiber volume fraction Vfa of the thick-walled part is smaller than the fiber volume fraction Vfb of the thin-walled part. The insert-molded body according to any one of claims 1 to 3.

7. The resin part is formed of a fiber-reinforced composite material, the resin part has a first resin layer and a second resin layer disposed closer to the metal part side than the first resin layer, and the fiber volume fraction Vf1 of the first resin layer is larger than the fiber volume fraction Vf2 of the second resin layer. The insert-molded body according to any one of claims 1 to 3.

8. The resin part is formed of a fiber-reinforced composite material, and the weight average fiber length of the reinforcing fibers contained in the resin part is 100 mm or less. The insert-molded body according to any one of claims 1 to 3.

9. When the direction perpendicular to the outer surface of the resin part is defined as the thickness direction, the difference in thickness between the thick-walled part and the thin-walled part is equal to or greater than the thickness of the metal part. The insert-molded body according to claim 2 or 3.

10. In a cross-sectional view perpendicular to the outer surface of the resin part, the thick-walled part and the thin-walled part are alternately positioned. The insert-molded body according to any one of claims 1 to 3.

11. At least a part of the metal component is arranged along the uneven wall portion or the thin wall portion, and the relationship between the flatness Fa of the resin component and the difference h in thickness between the uneven wall portion and the thin wall portion is 0 < Fa / h < 1.

3. The insert molded body according to claim 10.

12. A battery tray or a protective cover for a battery tray, including the insert molded body according to any one of claims 1 to 3, wherein the metal component is an electric circuit for impact detection.

13. An inverter box including the insert molded body according to any one of claims 1 to 3, wherein the metal component is an electric circuit.

14. A method for manufacturing an insert molded body having a resin component and a metal component, The resin component has an uneven wall portion and a thin wall portion thinner than the uneven wall portion, At least a part of the metal component is arranged on the outer surface of the resin component along the uneven wall portion or the thin wall portion, The metal component has a turning portion whose extending direction on the outer surface is changed, The method for manufacturing the insert molded body includes a step of fixing the resin component and the metal component to each other at the turning portion.

15. The insert molded body further has a sealing layer for sealing the metal component, The method for manufacturing the insert molded body includes a step of molding the sealing layer together with the resin component and the metal component. The method for manufacturing the insert molded body according to claim 14.

Images