Shell structure and manufacturing method thereof

Abstract

Provided is a case structure in which a heat-generating component is housed, the case structure being capable of effectively diffusing heat generated by the heat-generating component to the outside, and being lightweight and easy to manufacture. This case structure is provided with: a case containing a heat-dissipating resin; and a heat-generating component housed in a case, the case having a partition wall portion integrally formed by resin molding on an inner surface thereof toward the heat-generating component and surrounding the heat-generating component, the portion surrounded by the partition wall portion and the case being a heat-generating component housing portion capable of housing the heat-generating component, in the heat-generating member accommodating portion, a thermally conductive grease is interposed between the heat-generating member and the facing surface of the partition wall portion.

Description

Technical Field

[0001] This invention relates to a shell structure and its manufacturing method. Background Technology

[0002] Traditionally, electric vehicles, such as electric cars or hybrid vehicles, which use electric motors as one of their drive sources, have been equipped with power conversion devices. Examples of power conversion devices include chargers that convert commercial AC power to DC power to charge high-voltage batteries, DC / DC converters that convert DC power from high-voltage batteries to the voltage of batteries used in auxiliary equipment, and inverters that convert DC power from batteries into AC power for the electric motor.

[0003] Power conversion devices used in electric vehicles employ numerous electronic components, including semiconductor switching elements, various resistors, aluminum electrolytic capacitors, reactors, and transformers. Most of these electronic components are self-heating devices that generate heat through conduction. Due to the heat generated by these components, the power conversion device becomes a high-temperature environment. Therefore, the power conversion device must efficiently dissipate heat from the housing to the outside to cool the heat-generating components.

[0004] Patent Document 1 discloses a power conversion device comprising: a printed circuit board; an electromagnetic induction device electrically connected to the printed circuit board; a cooling unit disposed opposite to the printed circuit board with the electromagnetic induction device in between, for cooling the electromagnetic induction device; and a housing that houses the electromagnetic induction device, having a U-shaped cross-section and being thermally conductive and electrically insulating.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 2015-89179 Summary of the Invention

[0008] The technical problem solved by the invention

[0009] The cooling section of the power conversion device is formed separately from the outer casing, which has thermal conductivity and electrical insulation. A grease, serving as a heat dissipation component, lies between the cooling section and the outer casing. The coefficients of thermal expansion of the cooling section, the outer casing, and the grease differ when heated. Therefore, when heat is generated from the heat-generating components of the power conversion device, gaps arise due to the difference in the degree of expansion between these components, resulting in reduced sealing. Furthermore, the interfacial thermal conductivity between adjacent components in the cooling section, the outer casing, and the grease decreases, leading to a problem where the heat generated by the heat-generating components cannot be smoothly transferred to the outer casing and instead diffuses to the outside.

[0010] Because the housing is configured to contact the printed circuit board via an adhesive, the following problem arises: heat generated by the heat-generating components is transferred to the printed circuit board via the housing, and the circuits on the printed circuit board are affected by the heat.

[0011] The power conversion device requires a housing to be connected to both the cooling section and the printed circuit board, with the heating element housed within the housing. This complex manufacturing process results in low production efficiency.

[0012] Furthermore, in the power conversion device installed in electric vehicles, the casing is made of a metal with excellent thermal conductivity in order to efficiently dissipate the heat generated from the heat-generating components to the outside.

[0013] If the casing is made of metal, the weight of the power conversion device will increase, and the fuel efficiency of electric vehicles equipped with the power conversion device will decrease. Therefore, the power conversion device also needs to be lightweight.

[0014] The present invention provides a housing structure for housing a heating element, which can effectively diffuse the heat generated by the heating element to the outside, and can be manufactured in a lightweight and simple manner.

[0015] Technical means to solve the problem

[0016] The shell structure of the present invention has:

[0017] The housing contains a heat-dissipating resin;

[0018] A heating element, which is housed within the housing;

[0019] A partition wall is integrally formed on the inner surface of the housing facing the heating element by resin molding and surrounds the heating element;

[0020] A heating element receiving portion, which is formed by the portion surrounded by the partition wall and the housing and is capable of accommodating the heating element; and

[0021] Thermally conductive grease is disposed within the housing of the heating element, between the opposing surfaces of the heating element and the partition wall.

[0022] The housing structure of the present invention comprises: a housing containing a heat-dissipating resin; and a heating element housed within the housing, the housing having a partition wall portion integrally formed on its inner surface toward the heating element by resin molding and surrounding the heating element, the portion surrounded by the partition wall portion and the housing serving as a heating element receiving portion capable of accommodating the heating element, wherein a thermally conductive grease is disposed between the opposing surfaces of the heating element and the partition wall portion in the heating element receiving portion.

[0023] The method for manufacturing the shell structure of the present invention includes:

[0024] The process of assembling a heating element involves assembling and fixing the heating element onto a side housing containing heat-dissipating resin and having an opening.

[0025] The grease supply process supplies a fluid thermally conductive grease into a heating component receiving portion, the heating component receiving portion having an opening and being formed by a partition wall portion in another housing and a portion of another housing surrounded by the partition wall portion, the other housing having the partition wall portion integrally formed on the inner bottom surface by resin molding and containing a heat-dissipating resin.

[0026] The embedding process involves inserting the heating element, which is disposed and fixed to one side of the housing, into the heating element receiving portion of the other side of the housing, such that at least a portion of the heating element on one side of the housing is embedded in the thermally conductive grease within the heating element receiving portion of the other side of the housing; and

[0027] The thermally conductive grease is cured or hardened in a process that solidifies the grease.

[0028] The effects of the invention

[0029] The housing structure of the present invention has a partition wall portion integrally formed on the inner surface of the housing towards the heating element by resin molding, and surrounds the heating element, so that the heat generated by the heating element can be effectively diffused to the outside through the partition wall portion and the housing via thermally conductive grease.

[0030] The housing structure includes a shell containing heat-dissipating resin, thus enabling a lightweight housing structure, unlike the case of using a shell made of metal.

[0031] The shell and the partition wall are integrally formed by resin molding without a connecting interface, so that there is no reduction in thermal conductivity between the shell and the partition wall, and the heat generated by the heating element can be transferred from the partition wall to the shell and diffused smoothly from the shell to the outside.

[0032] Furthermore, since the housing and the partition wall do not have a connection interface at their joint, the housing and the partition wall will not accidentally separate due to the heat generated by the heating element. The housing and the partition wall are always integrated, and the heat generated by the heating element can be smoothly transferred to the housing through the partition wall.

[0033] In the housing structure, in the heating element housing, thermally conductive grease is placed between the heating element and the opposing surface of the housing opposite the heating element, so that the heat generated by the heating element can be smoothly transferred to the partition wall and the housing via the thermally conductive grease and released to the outside.

[0034] In the aforementioned housing structure, when the heating element is mounted on a printed circuit board, the heating element mounted on the printed circuit board can be mounted and fixed inside the housing, making it easy to implement cooling measures for the heating element.

[0035] In the housing structure, when a gap is formed between the partition wall and the printed circuit board opposite to the partition wall, the heat generated from the heat-generating component can be easily diffused outside the area containing the heat-generating component, and the heat-generating component can be cooled smoothly.

[0036] Because a gap is formed between the partition wall and the printed circuit board, the impact of heat transferred from the heat-generating component to the partition wall on the printed circuit board can be reduced, thus protecting the printed circuit board from the effects of heat.

[0037] Since a gap is formed between the partition wall and the printed circuit board, there is no need to provide a part on the printed circuit board for connecting the partition wall, which can achieve miniaturization of the printed circuit board, and thus miniaturization of the housing structure.

[0038] In the aforementioned housing structure, when a heat sink is integrally formed on the inner surface of the heating component housing by resin molding, the heat generated by the heating component can be effectively diffused to the outside through the housing via the heat sink, thereby improving the cooling effect of the heating component.

[0039] In the aforementioned housing structure, when thermally conductive grease is provided between the heat sinks, the contact area between the heat sinks and the thermally conductive grease can be increased, allowing the heat generated from the heat-generating component to diffuse smoothly through the housing to the outside, thereby effectively cooling the heat-generating component.

[0040] In the aforementioned housing structure, the housing comprises a side housing divided into two parts and a other side housing, such that the opening of the side housing coincides with the opening of the other side housing. When the opening ends of the side housing and the opening ends of the other side housing are integrated by an adhesive, the lightweight housing structure can be achieved.

[0041] The manufacturing method of the housing structure of the present invention includes the steps described above. Therefore, by inserting a heating element disposed and fixed to one side of the housing into a flowable thermally conductive grease within a heating element receiving portion of the other side of the housing, thereby burying at least a portion of the heating element within the thermally conductive grease, and then allowing the thermally conductive grease to solidify or harden, thermally conductive grease can be filled between at least a portion of the heating element and the opposing surface of the partition wall. Therefore, heat generated by the heating element can be smoothly released to the outside through the thermally conductive grease, the partition wall, and the housing, resulting in excellent cooling of the heating element.

[0042] In the manufacturing method of the shell structure, if an adhesive bonding process is used to integrate the opening ends of one side shell and the opening ends of the other side shell throughout their entire circumference, one side shell and the other side shell can be bonded together by adhesive, and the resulting shell structure has excellent lightweight properties.

[0043] In the manufacturing method of the housing structure, when a mark indicating the required amount of fluid thermally conductive grease is formed on the inner surface of the partition wall of the other side of the housing, an appropriate amount of thermally conductive grease can be supplied to the heating component housing. Thermally conductive grease can be reliably filled between at least a portion of the heating component and the opposing surface of the partition wall. As a result, the heat generated from the heating component can be released more smoothly to the outside through the thermally conductive grease, the partition wall, and the housing, thereby achieving an excellent cooling effect on the heating component. Attached Figure Description

[0044] Figure 1 This is a cross-sectional view showing the shell structure of the present invention.

[0045] Figure 2 This is a cross-sectional view showing a portion of the manufacturing process of the housing structure of the present invention.

[0046] Figure 3 This is a perspective view showing an example of the other side of the shell.

[0047] Figure 4 This is a cross-sectional view showing another example of a shell structure.

[0048] Figure 5 This is a cross-sectional view showing another example of a shell structure.

[0049] Figure 6 This is a cross-sectional view showing another example of a shell structure.

[0050] Figure 7This is a cross-sectional view showing another example of a shell structure.

[0051] Figure 8 This is a cross-sectional view showing another example of a shell structure.

[0052] Figure 9 This is a cross-sectional view of the shell structure used as a comparative example. Detailed Implementation

[0053] An example of the housing structure of the present invention will be described with reference to the accompanying drawings. Figures 1-3 As shown, the shell structure A includes a shell 1, which is divided into two parts, comprising a side shell 11 and a side shell 12. The side shell 11 and the side shell 12 are manufactured using common resin molding methods such as injection molding and blow molding. The side shell 11, the partition wall and heat sinks 12h and 12i (hereinafter referred to as heat sinks), and the side shell 12 constituting the shell 1 are formed of a heat-dissipating resin, giving the shell 1 excellent thermal conductivity. It should be noted that the heat-dissipating resin is formed by incorporating a thermally conductive material with higher thermal conductivity than the synthetic resin itself into the synthetic resin. Examples of thermally conductive materials include, for example, thermally conductive microparticles such as graphite, carbon black, and metal microparticles, as well as thermally conductive fibers such as carbon fiber and metal fiber.

[0054] Either or both of the side shell 11 and the other side shell 12 are preferably manufactured by a resin molding process that thermoforms the raw resin into the desired shape in only one step. By manufacturing with only one resin molding process, the side shell 11 and / or the other side shell 12 can be molded articles without any adhesive or heat-fused parts in their entirety, and have excellent thermal conductivity.

[0055] The thermal conductivity of the heat-dissipating resin is preferably 2.0 W / m·K or higher, more preferably 4.0 W / m·K or higher, and even more preferably 8.0 W / m·K or higher. The thermal conductivity of the heat-dissipating resin is preferably 50.0 W / m·K or lower. It should be noted that the thermal conductivity of the heat-dissipating resin is a value measured at 25°C using the laser flash method.

[0056] One side housing 11 has a bottom 11a and a peripheral wall portion 11b, the peripheral wall portion 11b being integrally formed throughout the entire periphery of the outer peripheral edge of the bottom 11a. A space portion 11c is formed in the part of the one side housing 11 surrounded by the bottom 11a and the peripheral wall portion 11b. The space portion 11c can be equipped with an electronic component including a heating element B and has an opening portion 11d that is open all over the surface.

[0057] The other side of the housing 12 has a bottom 12a and a peripheral wall portion 12b, which is integrally formed throughout the entire periphery of the outer peripheral edge of the bottom 12a. The other side of the housing 12 has a space portion 12c in the part surrounded by the bottom 12a and the peripheral wall portion 12b. The space portion 12c can be equipped with electronic components including the heating element B, and has an opening portion 12d that is open all over the surface.

[0058] The opening 11d of the space portion 11c of one side housing 11 and the opening 12d of the space portion 12c of the other side housing 12 are formed to have the same shape. When one side housing 11 and the other side housing 12 are overlapped with the openings 11d and 12d of these spaces 11c and 12c facing each other, the frame-shaped end edge of the peripheral wall portion 11b of one side housing 11 and the frame-shaped end edge of the peripheral wall portion 12b of the other side housing 12 are aligned with each other circumferentially. The spaces 11c and 12c of one side housing 11 and the other side housing 12 are closed, and an electronic component receiving portion 1a that can accommodate electronic components is formed by the spaces 11c and 12c of one side housing 11 and the other side housing 12. The frame-shaped end edge of the peripheral wall portion 11b of one side housing 11 and the frame-shaped end edge of the peripheral wall portion 12b of the other side housing 12 are bonded together with adhesive G. Therefore, the housing structure has excellent lightweight properties. It should be noted that, on one side of the housing 11 and / or the other side of the housing 12, a cooling medium flow path I is formed as needed for the flow of cooling medium (e.g., water, air, etc.) used to cool one side of the housing 11 and / or the other side of the housing 12.

[0059] An electronic component C, including a heat-generating component B, is disposed and fixed in the space 11c of one side of the housing 11. The heat-generating component B is a component that generates heat through its use, such as a reactor, transformer, coil, or capacitor. The electronic component C can be a separate heat-generating component B, or it can be a component that is electrically connected to and fixed on the printed circuit board D.

[0060] like Figure 2 and Figure 3As shown, one or more partition walls 12f are integrally protruding from the inner surface of the bottom 12a of the other housing 12. These partition walls 12f protrude towards the heating element B, which is disposed and fixed to one housing 11, and partially or entirely surround the heating element B. The partition walls 12f of the other housing 12 are integrally formed with the bottom 12a during resin molding of the other housing 12, and there is no connection interface between the partition walls 12f and the bottom 12a. Therefore, when using the housing structure, the partition walls 12f and the bottom 12a will not separate due to deformation caused by heat generated in the heating element B, and there is no reduction in thermal conductivity caused by the connection interface when conducting heat from the partition walls 12f to the bottom 12a. Thus, the heat generated in the heating element B can be smoothly diffused from the bottom 12a to the outside via the partition walls 12f. In this invention, "no connection interface between the two components" means that, in the state where the two components are integrated, there is no adhesive portion or heat-fused portion at the boundary between the two components. "No connection interface between the partition wall portion 12f and the bottom 12a" means that there is no adhesive portion or heat-fused portion at the boundary between the partition wall portion 12f and the bottom 12a. Preferably, the bottom 12a of the other side shell 12 and the partition wall portion 12f integrally formed with the bottom 12a are simultaneously thermoformed by a resin molding process that thermoforms the raw material resin into the desired shape. For example, when the other side shell 12 is formed by injection molding, if raw material resin is supplied to the cavity of the molding metal mold used to form the other side shell 12, and the bottom 12a of the other side shell 12 and the partition wall portion 12f integrally formed with the bottom 12a are thermoformed simultaneously, the other side shell 12 can be manufactured without a connection interface between the bottom 12a and the partition wall portion 12f.

[0061] A heating element receiving portion 12g is formed by the inner surface of the partition wall portion 12f of the other housing 12 and the inner surface of the bottom 12a surrounded by the partition wall portion 12f. The front end of the heating element receiving portion 12g is fully open and can partially or completely accommodate the heating element B. The heating element receiving portion 12g is sized to accommodate a part or the entire heating element B disposed and fixed to one housing 11. The shape of the partition wall portion 12f is not particularly limited. The shape of the partition wall portion 12f is appropriately adjusted according to the shape of the heating element B it accommodates, for example, it can be cylindrical (square tube, cylindrical, etc.). Adjacent partition wall portions 12f can also be connected and integrated with each other by sharing a part of the partition wall portion.

[0062] Furthermore, the heating element receiving portion 12g of the other housing 12 houses a part or the entire heating element B disposed and fixed to the space portion 11c of the housing 11 on one side. One heating element B can be housed in one heating element receiving portion 12g, or multiple heating elements B can be housed in one heating element receiving portion 12g.

[0063] A thermally conductive grease F is filled in a solid state in the space between the inner surface of the heating element B and the opposing partition wall 12f, and the inner surface of the bottom 12a of the other side of the housing 12. It should be noted that the thermally conductive grease is composed of a matrix such as an organopolysiloxane or polyα-olefin, which is liquid when uncured, containing thermally conductive filler materials such as metal oxide powder, metal nitride powder, metal carbide powder, or metal hydroxide powder. In applications requiring insulation, metal oxide powder, metal nitride powder, metal carbide powder, or metal hydroxide powder are preferably used as the thermally conductive filler material. Examples of metal oxides include aluminum oxide, magnesium oxide, zinc oxide, and silicon oxide. Examples of metal hydroxides include aluminum hydroxide and magnesium hydroxide. Examples of metal nitrides include aluminum nitride, silicon nitride, and boron nitride. Furthermore, metal powders such as aluminum and copper, graphite, and carbon fibers can also be used as thermally conductive filler materials. Hardened thermally conductive greases are preferred as they prevent leakage to the surrounding area.

[0064] The thermal conductivity of the thermally conductive grease is preferably 2.0 W / m·K or higher, more preferably 3.0 W / m·K or higher, and even more preferably 4.5 W / m·K or higher. The thermal conductivity of the thermally conductive grease is preferably 40.0 W / m·K or lower. It should be noted that the thermal conductivity of the thermally conductive grease is a value measured at 25°C using the laser flash method.

[0065] It is not necessary to fill the entire space between the heating element B and the inner surface of the partition wall 12f opposite to the heating element B and the inner surface of the bottom 12a of the other side housing 12 with thermally conductive grease F. It is also possible to fill only a part of the space with thermally conductive grease F. From the perspective of being able to transfer the heat generated by the heating element B directly to the bottom 12a of the other side housing 12 and diffuse it smoothly to the outside, it is preferable to fill the entire space between the heating element B and the inner surface of the bottom 12a of the other side housing 12 with thermally conductive grease F.

[0066] The opening end of the partition wall portion 12f of the other housing 12 does not reach the substrate on which the heating element B is fixed, i.e., the bottom 11a of one housing 11 or the printed circuit board D. A gap portion E is formed between the opening end (front end) of the partition wall portion 12f and the substrate (the bottom 11a of one housing 11 or the printed circuit board D) opposite to the opening end (front end).

[0067] Furthermore, the heat generated by the heating element B housed within a heating element housing 12g diffuses outward through the bottom 12a of the other side of the housing 12 via the thermally conductive grease F and the partition walls 12f constituting the heating element housing 12g. Additionally, it flows outward through the gap E formed between a partition wall 12f and the substrate, and diffuses outward through the bottom 12a of the other side of the housing 12 via other partition walls 12f disposed within the electronic component housing 1a of the housing 1. Therefore, the heat generated by the heating element B can be diffused outward through multiple partition walls 12f, improving the cooling effect of the heating element B.

[0068] Furthermore, when the heating element B is disposed on the printed circuit board D, a circuit is formed on the printed circuit board D. By preventing the front end of the partition wall 12f from reaching the printed circuit board D to form the gap E, the impact of heat transferred to the partition wall 12f on the printed circuit board D can be reduced, and damage to the printed circuit board D due to heat generated by the heating element B can be prevented.

[0069] Furthermore, since the partition wall portion 12f does not contact the printed circuit board D, there is no need to provide an area for the partition wall portion 12f to abut against the printed circuit board D. Excess parts can be eliminated from the printed circuit board D to achieve miniaturization of the printed circuit board D. In addition, the housing structure A can be miniaturized and made lighter.

[0070] Preferably, multiple heat sinks 12h are integrally provided on the inner surface of the bottom 12a portion surrounded by the inner surface of the partition wall portion 12f of the other housing 12, protruding toward the heat-generating component receiving portion 12g. In the other housing 12, it is not necessary to integrally provide the heat sinks 12h on the entire inner surface of the bottom 12a portion surrounded by the inner surface of the partition wall portion 12f; the heat sinks 12h can be integrally provided partially. The heat sinks 12h are provided on the inner surface of the bottom 12a during the resin molding of the other housing 12, and are integrally formed with the bottom 12a, with no connection interface between the heat sinks 12h and the bottom 12a. The heat sinks 12h are formed of a heat-dissipating resin. Furthermore, thermally conductive grease F is also filled between the opposing surfaces of the multiple heat sinks 12h. Therefore, when using housing structure A, the heat sink 12h and the bottom 12a will not separate from each other due to deformation caused by heat generated in the heat-generating component B, and no reduction in thermal conductivity due to the connection interface will occur when heat is conducted from the heat sink 12h to the bottom 12a. Therefore, the heat generated in the heat-generating component B diffuses smoothly from the bottom 12a to the outside via the heat sink 12h and the thermally conductive grease F. "No connection interface exists between the heat sink 12h and the bottom 12a" means that there is no adhesive part or heat-fused part at the boundary between the heat sink 12h and the bottom 12a. Preferably, the bottom 12a of the other side of the housing 12 and the heat sink 12h integrated with the bottom 12a are simultaneously thermoformed by a resin molding process in which the raw material resin is thermoformed into the desired shape. For example, if the other side housing 12 is formed by injection molding, and raw material resin is supplied to the cavity of the molding metal mold used to form the other side housing 12, and the bottom 12a of the other side housing 12 and the heat sink 12h integrally formed with the bottom 12a are thermoformed, the other side housing 12 can be manufactured without a connection interface between the bottom 12a and the heat sink 12h.

[0071] In addition, such as Figure 4As shown, multiple heat sinks 12i can also be integrally formed on the outer surface of the housing 1 (preferably the outer surface of the other housing 12). The heat sinks 12i are formed integrally with the outer surface of the housing 1 (preferably the bottom 12a of the other housing 12) during resin molding of the housing 1 (preferably the other housing 12), and there is no connecting interface between the heat sinks 12i and the housing 1 (preferably the bottom 12a of the other housing 12). The heat sinks 12i are formed of a heat-dissipating resin. Therefore, when using housing structure A, the heat sinks 12i and the housing 1 will not separate from each other due to deformation caused by heat generated in the heat-generating component B, and there is no reduction in thermal conductivity caused by the connecting interface when conducting heat from the heat sinks 12i to the housing 1. Thus, the heat generated in the heat-generating component B can be more effectively diffused to the outside from the heat sinks 12i. "No connecting interface between the heat sinks 12i and the housing 1" means that there is no adhesive or heat-fused portion at the boundary between the heat sinks 12i and the housing 1. Preferably, the housing 1 and the heat sink 12i integrally formed with the housing 1 are simultaneously thermoformed by a resin molding process in which the raw material resin is thermoformed into the desired shape. For example, when the housing 1 is formed by injection molding, if the raw material resin is supplied to the cavity of the molding metal mold used to form the housing 1, and the housing 1 and the heat sink 12i integrally formed with the housing 1 are thermoformed at the same time, the housing 1 can be manufactured without a connection interface between the housing 1 and the heat sink 12i.

[0072] A portion of the heat sink 12i formed on the outer surface of the housing 1 is preferably formed on the outer surface of the other housing 12 or the outer surface of the bottom 12a, located on the side opposite to the partition wall 12f, separated from the other housing 12 or its bottom 12a. Preferably, the heat sink 12i is formed on the portion of the partition wall 12f projected onto the outer surface of the housing 1 in a direction opposite to its forming direction. Heat emitted from the heat-generating component B can be efficiently diffused to the outside of the housing 1 via the partition wall 12f and the heat sink 12i.

[0073] Next, the manufacturing method of the housing structure will be described. In the space portion 11c of one side of the housing 11, the electronic component C, which includes the heat-generating component B, is arranged and fixed in a common manner (heat-generating component arrangement process).

[0074] On the other hand, such as Figure 2As shown, the other housing 12 is placed on any mounting surface H with the heating element receiving portion 12g, which is surrounded by the partition wall portion 12f, opening upwards. A fluid thermally conductive grease F is supplied into the heating element receiving portion 12g of the other housing 12. It should be noted that if the thermally conductive grease F is solid under normal conditions, it needs to be preheated to a fluid state. Preferably, markings such as scales or steps indicating the necessary amount of thermally conductive grease F are formed on the inner surface of the partition wall portion 12f of the other housing 12. The fluid thermally conductive grease F is supplied into the heating element receiving portion 12g until the required amount is indicated by the markings (grease supply process).

[0075] Next, as Figure 2 As shown, one side of the housing 11 is flipped upside down, so that the opening 11d of the space portion 11c of one side of the housing 11 faces the opening 12d of the space portion 12c of the other side of the housing 12. Furthermore, the heating element B on one side of the housing 11 is positioned above each heating element receiving portion 12g of the other side of the housing 12, and the heating element B is embedded in the thermally conductive grease F within the heating element receiving portion 12g.

[0076] Then, one side housing 11 is moved towards the other side housing 12 (downward), so that the frame-shaped end edge of the peripheral wall portion 11b of one side housing 11 is aligned with the frame-shaped end edge of the peripheral wall portion 12b of the other side housing 12 around the circumference, and part or all of the heating components B fixed to one side housing 11 are buried in the thermally conductive grease F in the heating component receiving portions 12g of the other side housing 12 (burying process). Since the heating components B are inserted from above and buried in the thermally conductive grease F stored in the heating component receiving portions 12g of the other side housing 12, this can be done in a simple way, and the thermally conductive grease F can be filled without gaps in the space formed between at least the front end of the heating component B and the space between the partition wall portion 12f and the bottom 12a opposite to it, and the heat generated by the heating component B can be efficiently guided to the partition wall portion 12f and the bottom 12a and diffused to the outside via the thermally conductive grease F.

[0077] An adhesive G is applied across the entire surface between the frame-shaped end edge of the peripheral wall portion 11b of one side housing 11 and the opposing surface of the frame-shaped end edge of the peripheral wall portion 12b of the other side housing 12, thereby integrating one side housing 11 and the other side housing 12 together. In this state, the spaces 11c and 12c of one side housing 11 and the other side housing 12 form an electronic component receiving portion 1a, which houses an electronic component C containing a heating component B.

[0078] On the other hand, the housing structure A is manufactured by cooling, solidifying or hardening the thermally conductive grease F in each heat-generating component receiving portion 12g of the other housing 12 to make it lose its fluidity and solidify (thermally conductive grease fixing process), thereby fixing the heat-generating component B in a state in which it is partially or entirely buried in the thermally conductive grease F.

[0079] As described above, the housing structure A can be easily manufactured by supplying a fluid thermally conductive grease F into each heating component receiving portion 12g of the other housing 12 and burying part or all of the heating component B disposed and fixed to one housing 11 from above in the thermally conductive grease.

[0080] Furthermore, when using housing structure A, heat is generated in the heat-generating component B housed within the electronic component housing 1a. This heat is efficiently cooled by diffusing to the outside through the bottom 12a of the other side housing 12, which is formed by heat-conducting grease F and / or heat-dissipating resin (in addition, heat sinks 12i, 12h).

[0081] As described above, the housing structure A allows heat generated by the heat-generating component B to dissipate smoothly to the outside of the housing 1, protecting the electronic component C disposed within the housing 1 from heat and ensuring stable operation of the electronic component C. Furthermore, the housing structure A is lightweight, thus allowing it to be mounted on electric vehicles and the like while housing a power conversion device.

[0082] Example

[0083] The present invention will be described in more detail below using examples, but the invention is not limited thereto. The specific numerical values ​​of proportions (including proportions), physical property values, parameters, etc. used in the following description can be replaced with the upper limit values ​​(defined in the form of "below" or "less than") or lower limit values ​​(defined in the form of "above" or "more than") of the corresponding proportions (including proportions), physical property values, parameters, etc. described in the "Detailed Description of the Embodiments" section.

[0084] (Example 1)

[0085] like Figure 5As shown, a side housing 11 is prepared having a bottom 11a and a peripheral wall portion 11b integrally formed throughout the entire circumference of the outer peripheral edge of the bottom 11a. A space portion 11c is formed in the portion of the side housing 11 surrounded by the bottom 11a and the peripheral wall portion 11b. This space portion 11c can be equipped with an electronic component including a heating element B and has an opening portion 11d that is open over its entire surface. One side of the shell 11 is composed of a heat-dissipating resin (thermal conductivity: 12.3 W / m·K) containing 100 parts by weight of polypropylene (trade name "BC10HRF" manufactured by JAPAN POLYPROPYLENE), 100 parts by weight of expanded graphite (trade name "EXP-80S220" manufactured by Fuji Graphite Industries, Ltd., expansion ratio: 200 mL / g, volume average particle size: 180 μm) and 100 parts by weight of flake graphite (trade name "CPB-100" manufactured by CHUETSU GRAPHITE WORKS, volume average particle size: 100 μm).

[0086] A second housing 12 is prepared, having a bottom 12a and a peripheral wall portion 12b integrally formed along the entire circumference of the outer periphery of the bottom 12a. The second housing 12 has a space portion 12c formed in the portion surrounded by the bottom 12a and the peripheral wall portion 12b. This space portion 12c can accommodate electronic components including a heat-generating component B and has an opening 12d that is open over its entire surface. The second housing 12 is made of the same heat-dissipating resin as the first housing 11.

[0087] When one side housing 11 and the other side housing 12 are overlapped with their openings 11d and 12d facing each other, the openings 11d and 12d of the spaces 11c and 12c are closed, forming an electronic component receiving portion 1a that can accommodate electronic components. The frame-shaped end edge of the peripheral wall portion 11b of one side housing 11 and the frame-shaped end edge of the peripheral wall portion 12b of the other side housing 12 are bonded together by an adhesive G. The housing 1 is constituted by one side housing 11 and the other side housing 12.

[0088] A heating element B is disposed and fixed in the space 11c of one side housing 11. The heating element B is fixed on the printed circuit board D. A cylindrical partition wall 12f is integrally formed on the inner surface of the bottom 12a of the other side housing 12. The partition wall 12f protrudes towards the heating element B disposed and fixed to the one side housing 11 and partially surrounds the heating element B. The partition wall 12f of the other side housing 12 is integrally formed with the bottom 12a during the resin molding of the other side housing 12, and there is no connection interface between the partition wall 12f and the bottom 12a. The partition wall 12f is made of the same heat-dissipating resin as the one side housing 11.

[0089] A heating element receiving portion 12g is formed by the inner surface of the partition wall portion 12f of the other housing 12 and the inner surface of the bottom 12a surrounded by the partition wall portion 12f. The front end of the heating element receiving portion 12g is open all over and can partially or completely accommodate the heating element B. A portion or the entire heating element B, which is disposed and fixed to the space portion 11c of the other housing 11, is housed in the heating element receiving portion 12g of the other housing 12.

[0090] On the inner surface of the bottom 12a portion of the other housing 12, which is surrounded by the inner surface of the partition wall portion 12f, a plurality of heat sinks 12h are integrally provided protruding toward the heat-generating component receiving portion 12g. The heat sinks 12h are made of the same heat-dissipating resin as the other housing 11. There is no connection interface between the heat sinks 12h and the bottom 12a. The heat sinks 12h are made of the same heat-dissipating resin as the other housing 12.

[0091] Furthermore, multiple heat sinks 12i are integrally protruding from the outer surface of the other housing 12. The heat sinks 12i are integrally formed with the bottom 12a during resin molding of the other housing 12, protruding from the outer surface of the bottom 12a, and there is no connection interface between the heat sinks 12i and the bottom 12a. The heat sinks 12i are made of the same heat-dissipating resin as the other housing 12. A portion of the heat sink 12i is formed on the outer surface of the bottom 12a, on the side opposite to the partition wall 12f, separated from the bottom 12a of the other housing 12. Specifically, when the partition wall 12f is oriented in the direction opposite to its forming direction (in... Figure 5 The portion of the heat sink 12i is formed on the outer surface of the housing 1 (the middle part is above).

[0092] The space formed between the inner surface of the heating element B and the inner surface of the partition wall 12f opposite to it, and the inner surface of the bottom 12a of the other housing 12, is filled with thermally conductive grease F (thermal conductivity: 6 W / m·K) in a solid state. The opening end of the partition wall 12f of the other housing 12 does not reach the printed circuit board D on which the heating element B is fixed.

[0093] Driven by the shell structure A constructed as described above ( Figure 5 Heating component B. The temperature T on the surface of heating component B was measured 10 minutes after it was driven. The temperature T is shown in Table 1.

[0094] (Example 2)

[0095] A shell structure A was prepared that has the same structure as the shell structure of Embodiment 1, except that no heat sink 12h is formed on the inner surface of the bottom 12a of the other side shell 12 and the inner surface of the bottom 12a is formed as a smooth surface. Figure 6 The heating element B of the housing structure A was driven. The temperature T on the surface of the heating element B was measured 10 minutes after it was driven. The temperature T is shown in Table 1.

[0096] (Example 3)

[0097] A housing structure A (without heat sinks 12i formed on the outer surface of the bottom 12a of the other side housing 12 and with the outer surface of the bottom 12a being formed as a flat surface) has the same structure as the housing structure of Embodiment 1. Figure 7 The heating element B of the housing structure A was driven. The temperature T on the surface of the heating element B was measured 10 minutes after it was driven. The temperature T is shown in Table 1.

[0098] (Example 4)

[0099] A shell structure A is prepared that has the same structure as the shell structure of Embodiment 1, except that heat sinks 12h and 12i are not formed on the inner and outer surfaces of the bottom 12a of the other side shell 12, and the inner and outer surfaces of the bottom 12a are formed as flat surfaces. Figure 8 The heating element B of the housing structure A was driven. The temperature T on the surface of the heating element B was measured 10 minutes after it was driven. The temperature T is shown in Table 1.

[0100] (Comparative Example 1)

[0101] A housing structure A was prepared that has the same structure as the housing structure of Example 4, except that no partition wall is formed on the inner surface of the bottom 12a of the other housing 12 and no thermally conductive grease is used. Figure 9 An air layer is formed in the space between the inner surface of the housing 1 and the heating element B, and the housing 1 and the heating element B are not in contact. The heating element B of the housing structure A is driven. The temperature T of the surface of the heating element B is measured 10 minutes after the heating element B is driven. The temperature T is shown in Table 1.

[0102]

[0103] (Cross-reference to related applications)

[0104] This application claims priority based on Japanese Patent Application No. 2023-104542, filed on June 26, 2023, the disclosure of which is incorporated herein by reference in its entirety.

[0105] Industrial applicability

[0106] According to the housing structure of the present invention, heat generated in the heating component can be effectively diffused to the outside through the thermally conductive grease via the partition wall and the housing, and it is lightweight, thus making it suitable for power conversion devices used in electric vehicles, etc.

[0107] Symbol Explanation

[0108] 1. Shell

[0109] 1a Electronic component housing

[0110] 11. One side of the shell

[0111] 11a Bottom

[0112] 11b Peripheral section

[0113] 11c Space Department

[0114] 11d opening

[0115] 12. The other side of the shell

[0116] 12a Bottom

[0117] 12b Peripheral section

[0118] 12c Space Department

[0119] 12d opening

[0120] 12f partition wall section

[0121] 12g Heating Component Receptacle

[0122] 12h heatsink

[0123] A shell structure

[0124] B Heating Component

[0125] C Electronic Components

[0126] D Printed Circuit Board

[0127] E Gap

[0128] F Thermal grease

[0129] G adhesive

Claims

1. A housing structure, comprising: a housing including a heat-dissipating resin; a heat-generating component housed in the housing; a partition wall portion integrally formed by resin molding on an inner surface of the housing toward the heat-generating component and surrounding the heat-generating component; a heat-generating component housing portion configured by a portion surrounded by the partition wall portion and the housing and capable of housing the heat-generating component; and a thermally conductive grease in the heat-generating component housing portion between the heat-generating component and an opposing surface of the partition wall portion.

2. The housing structure according to claim 1, wherein the thermally conductive grease is between the heat-generating component and an opposing surface of the housing opposite the heat-generating component in the heat-generating component housing portion.

3. The housing structure according to claim 1 or 2, wherein the heat-generating component is provided on a printed wiring board.

4. The housing structure according to claim 3, wherein a gap portion is formed between the partition wall portion and the printed wiring board opposite the partition wall portion.

5. The housing structure according to claim 1 or 2, wherein an inner surface of the heat-generating component housing portion has a heat-dissipating fin integrally formed by resin molding.

6. The housing structure according to claim 5, comprising: the thermally conductive grease provided between the heat-dissipating fins.

7. The housing structure according to claim 1, wherein the housing includes a one-side housing and another-side housing that are integrally configured in a state where an opening portion of the one-side housing and an opening portion of the another-side housing are butted against each other, and an opening end portion of the one-side housing and an opening end portion of the another-side housing are integrated by an adhesive.

8. The housing structure according to claim 1 or 2, wherein the heat-generating component is at least one heat-generating component selected from the group consisting of an electric reactor, a transformer, a coil, and a capacitor.

9. The housing structure according to claim 1 or 2, wherein a heat-dissipating fin is formed on a portion of an outer surface of the housing projected toward an opposite side of the partition wall portion from a direction in which the partition wall portion is formed.

10. A manufacturing method of a housing structure, comprising: a heat-generating component-providing step of providing and fixing a heat-generating component on a one-side housing including a heat-dissipating resin and having an opening portion; a grease-feeding step of feeding a thermally conductive grease having fluidity into a heat-generating component housing portion having an opening portion and formed by a partition wall portion in another-side housing and another-side housing portion surrounded by the partition wall portion, the another-side housing integrally formed with the partition wall portion on an inner bottom surface by resin molding and including a heat-dissipating resin; a burying step of inserting the heat-generating component provided and fixed on the one-side housing into the heat-generating component housing portion of the another-side housing so as to bury at least a portion of the heat-generating component of the one-side housing in the thermally conductive grease in the heat-generating component housing portion of the another-side housing; and a thermally conductive grease-fixing step of solidifying or hardening the thermally conductive grease.

11. The manufacturing method of a housing structure according to claim 10, wherein ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ An inner surface of the heat generating component housing portion is formed integrally with fins by resin molding.

12. The manufacturing method of a housing structure according to claim 10 or 11, wherein the burying process includes: a process of placing the other-side housing in a state in which an opening portion of a heat generating component housing portion thereof is open upward on a placement surface; a process of arranging, above the other-side housing, the heat generating component arranged in the one-side housing in a manner so as to oppose the opening portion of the heat generating component housing portion of the other-side housing; and a process of bringing the one-side housing and the other-side housing close to each other, inserting the heat generating component arranged and fixed to the one-side housing into the heat generating component housing portion of the other-side housing, and burying at least a portion of the heat generating component in the one-side housing in the thermally conductive grease in the heat generating component housing portion of the other-side housing.

13. The manufacturing method of a housing structure according to claim 10 or 11, having: a bonding process of integrally bonding the opening end portion of the one-side housing and the opening end portion of the other-side housing with an adhesive over the entire periphery thereof.

14. The manufacturing method of a housing structure according to claim 10 or 11, wherein a mark for indicating a required amount of supply of the thermally conductive grease having fluidity is formed on an inner surface of the partition wall portion of the other-side housing.

15. The manufacturing method of a housing structure according to claim 14, wherein the mark is a scale or a step provided on the inner surface of the partition wall portion.

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