Magnesium alloy inverter heat dissipation shell and die-casting die and semi-solid die-casting process thereof

Abstract

The invention belongs to the technical field of inverters, and particularly relates to a magnesium alloy inverter heat dissipation shell and a die-casting die and a semi-solid die-casting process thereof. The integrated circuit module at least comprises a shell magnesium substrate and a heat conduction pipe, the heat conduction pipe is installed in the shell magnesium substrate, an installation boss is arranged on the shell magnesium substrate, an IC electronic element is installed on the installation boss through a conductive adhesive, and the heat conduction pipe is arranged at the position close to the installation boss. The heat dissipation shell is produced by adopting a magnesium alloy semi-solid die-casting process, the heat conduction pipe and the embedding structure of the magnesium alloy casting are processed, and the heat conduction pipe is embedded into the magnesium substrate in a suspended manner, so that the heat conduction pipe is completely wrapped in the magnesium substrate without gaps and hindrance; therefore, the working heat of the IC element can be quickly guided into the magnesium substrate through the efficient heat transfer medium in the heat conduction pipe and is dissipated through the cooling fins, so that the heat conduction efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of inverters, and in particular to a magnesium alloy inverter heat dissipation housing, a die-casting die thereof, and a semi-solid die-casting process. Background Art

[0002] PV inverters are one of the most important components in a photovoltaic power generation system. Their primary function is to convert direct current (DC) into alternating current (AC) to meet the needs of household, commercial, and industrial applications. Microinverters, generally referring to inverters with a power of 1000 watts or less and module-level MPPT (Multi-Purpose Point-Viewing) in photovoltaic power generation systems, are also known as micro photovoltaic grid-connected inverters. Their advantage is independent MPPT control for each module, significantly improving overall efficiency while avoiding the issues of centralized inverters, such as high DC voltage, poor low-light performance, and the "barrel effect" ("sweep away") effect.

[0003] To improve the heat dissipation efficiency of the inverter, the heat sink shell structure design has increased the heat dissipation efficiency of the shell to a certain extent by increasing the height of the heat sink and thinning the heat sink. However, due to the limitation of the thermal conductivity of the die-cast aluminum-silicon alloy material, for heat sink shells of the same size, simply changing the structure of the heat sink can no longer meet the high heat dissipation requirements of the inverter. It is necessary to consider other structural forms and materials of the heat sink shell to reduce the weight and improve the heat dissipation efficiency of the heat sink shell. Summary of the Invention

[0004] In response to the shortcomings of the existing technology, the present invention provides a magnesium alloy inverter heat dissipation housing, its die-casting mold and semi-solid die-casting process. The heat pipe is pre-buried in the internal position of the housing magnesium substrate in a suspended embedded structure through the semi-solid die-casting process, thereby improving the heat dissipation effect of the heat dissipation housing, aiming to solve the problems in the background technology.

[0005] In order to achieve the above technical objectives, the specific technical solutions of the present invention are as follows: the present invention proposes a magnesium alloy inverter heat dissipation housing, which at least includes a housing magnesium substrate and a heat pipe. The heat pipe is installed in the inner position of the shell magnesium base plate. The shell magnesium base plate is provided with a mounting boss. IC electronic components are mounted on the mounting boss through conductive glue. The heat pipe is arranged near the mounting boss.

[0006] As a preferred technical solution of the present invention, the heat pipe includes a stainless steel shell and a heat conducting medium located inside the stainless steel shell.

[0007] As a preferred technical solution of the present invention, the heat pipe is pre-buried in the interior of the magnesium base plate of the shell in a suspended embedded structure through a semi-solid die-casting process.

[0008] As a preferred technical solution of the present invention, a plurality of heat sinks are provided on the surface of the magnesium substrate of the shell.

[0009] A die-casting mold, comprising: The movable mold and the fixed mold are both provided with a mold cavity that matches the shape of the heat dissipation shell; The movable mold support and the fixed mold support, wherein the fixed mold support is used to clamp and fix the heat conduction pipe, and the movable mold support is used to tighten the heat conduction pipe; the movable mold support is installed in the mold cavity of the movable mold, and the fixed mold support is installed in the mold cavity of the fixed mold; The fixed mold is provided with an injection port for injecting semi-solid magnesium alloy slurry.

[0010] As a preferred technical solution of the present invention, the fixed mold support is provided with a clamping groove for clamping the heat conducting pipe, and the movable mold support is provided with a groove for tightening the heat conducting pipe.

[0011] As a preferred technical solution of the present invention, the movable die support and the fixed die support are both made of the same magnesium alloy AZ91D as the heat dissipation housing.

[0012] As a preferred technical solution of the present invention, the movable die support and the fixed die support are in a thin sheet structure.

[0013] A semi-solid die-casting process comprises the following steps: Step 1: Design the movable mold support and the fixed mold support for fixing the heat pipe, and install them in the mold cavities of the movable mold and the fixed mold respectively; Step 2: Preheat the heat pipe, and clamp and fix the preheated heat pipe on the fixed mold support; Step 3: The mold is closed, and the movable mold support is tightened against the heat pipe; Step 4: Inject the semi-solid magnesium alloy slurry into the mold cavity through the injection port, and melt the fixed mold support and the movable mold support into one piece with the magnesium alloy semi-solid slurry, so as to achieve the purpose of suspending and embedding the heat pipe in the magnesium base plate of the shell; Step 5: After the casting cools down, open the mold and take out the heat dissipation shell.

[0014] The beneficial effects of the present invention are:

[0015] 1. The present invention uses a magnesium alloy semi-solid die-casting process to produce a heat dissipation housing, processes an inlaid structure of a heat pipe and a magnesium alloy casting, and suspends and inlays the heat pipe into a magnesium base plate, so that the heat pipe is completely enclosed in the magnesium base plate without gaps or obstacles. Therefore, the operating heat of the IC component can be quickly transferred into the magnesium base plate through the efficient heat transfer medium in the heat pipe and dissipated through the heat sink, thereby improving the heat conduction efficiency and compensating for the material shortcoming of the low thermal conductivity of AZ91D magnesium alloy.

[0016] 2. In the present invention, when die-casting the heat pipe and the radiator shell, the heat pipe is supported by a movable die support and a fixed die support. The movable die support and the fixed die support are made of the same magnesium alloy as the radiator shell. During the die-casting process, the thin sheet support is completely melted during the semi-solid slurry filling process. After the support is melted, the heat pipe and the magnesium substrate of the shell are in contact without any partition. No holes will remain in the support part, so that the entire heat pipe is not exposed, thereby achieving the purpose of suspended inlay.

[0017] 3. The magnesium alloy heat dissipation shell used in the present invention can reduce weight compared to aluminum alloy, but the thermal conductivity of semi-solid die-cast magnesium alloy is lower than that of aluminum alloy. Therefore, the present invention uses pre-buried heat pipes to improve the thermal conductivity of the magnesium alloy heat dissipation shell, and the magnesium alloy heat dissipation shell achieves the purpose of lightweight and high thermal conductivity. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Schematic diagram of a partial cross section of a heat dissipation housing of a photovoltaic inverter according to an embodiment of the present invention.

[0019] Figure 2 This is a schematic diagram of the die-casting mold of the present invention before mold closing.

[0020] Figure 3 This is a schematic diagram of the die-casting mold after mold closing of the present invention.

[0021] Figure 4 for Figure 3 A partial enlarged view of point A in the middle.

[0022] Figure 5 Schematic diagram of an inverter heat dissipation housing with suspended and embedded heat pipes according to an embodiment of the present invention.

[0023] Figure 6 Flowchart of the semi-solid die casting process of the present invention.

[0024] In the figure: 1. Magnesium base plate of the shell; 2. Mounting boss; 3. IC electronic component; 4. Conductive adhesive; 5. Heat pipe; 6. Stainless steel shell; 7. Heat conducting medium; 8. Heat sink; 9. Moving mold support; 10. Fixed mold support; 11. Moving mold; 12. Fixed mold; 13. Injection port. DETAILED DESCRIPTION

[0025] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0026] This embodiment discloses a magnesium alloy inverter heat dissipation housing, such as Figure 1As shown, the present invention comprises at least a magnesium base plate 1 and a heat pipe 5. The heat pipe 5 is mounted inside the magnesium base plate 1. The magnesium base plate 1 is provided with a mounting boss 2. An IC electronic component 3 is mounted on the mounting boss 2 via a conductive adhesive 4. The heat pipe 5 is pre-embedded inside the magnesium base plate 1 in a suspended inlay structure using a semi-solid die-casting process, without being exposed from the magnesium base plate 1. It should be noted that the position where the heat pipe 5 is suspended and inlaid is close to the mounting position of the IC electronic component 3 in order to better conduct the working heat of the IC component. Therefore, the specific range of this corresponding position is not particularly limited, as long as it facilitates the heat pipe to quickly transfer the working heat of the IC component.

[0027] Preferably, the heat pipe 5 includes a stainless steel shell 6 and a heat-conducting medium 7 located inside the stainless steel shell 6. The stainless steel shell 6 has the advantages of corrosion resistance and high strength. The heat-conducting medium 7 can be a high-thermal-conductivity cold medium and can be sealed in the stainless steel shell 6.

[0028] Preferably, a plurality of heat sinks 8 are provided on the surface of the shell magnesium substrate 1 to improve the heat dissipation efficiency of the shell magnesium substrate 1 .

[0029] In the photovoltaic inverter heat sink housing provided in this embodiment, the stainless steel housing 6 of the heat pipe 5 is in direct contact with the magnesium base plate 1 of the heat sink housing. This allows the operating heat of the IC electronic components 3 to be transferred to the mounting boss 2 via the conductive adhesive 4. From there, it is transferred from the magnesium base plate 1 to the stainless steel housing 6 of the heat pipe 5. The highly thermally conductive medium 7 sealed within the heat pipe 5 then rapidly conducts the heat to the heat sink 8, ultimately dissipating the heat to the ambient environment.

[0030] In this embodiment, the heat pipe 5 is pre-buried in the corresponding position of the shell magnesium base plate 1 using a semi-solid alloy material in a suspended embedded structure. The specific implementation of this structure can be achieved through a special installation limiting structure, that is, a semi-solid die-casting process is used to achieve a suspended embedded structure of the heat pipe 5 and the magnesium alloy die-casting.

[0031] In this embodiment, the semi-solid die-casting part has a granular crystal structure, small alloy molecular gaps, and high tissue density, which is conducive to the heat dissipation of electronic components. In addition, this embodiment adopts semi-solid slurry die-casting production, the density of the shell magnesium substrate 1 is greater than 1.85g / cm3, and the thickness of the heat sink 8 is 0.8-2.0mm. Through the dense semi-solid structure, the thin-walled heat sink 8, and the locally embedded heat pipe 5, the heat conduction efficiency of the photovoltaic inverter heat dissipation shell can be improved by 10%-30%.

[0032] like Figure 2-Figure 4As shown, this embodiment also discloses a die-casting mold for producing the above-mentioned inverter heat dissipation housing, the mold comprising: a movable mold 11 and a fixed mold 12; the inner wall surfaces of the movable mold 11 and the fixed mold 12 are both provided with a mold cavity that matches the shape of the heat dissipation housing; a support member, wherein the support member comprises a movable mold support member 9 and a fixed mold support member 10, wherein the fixed mold support member 10 is used to clamp and fix the heat conduction pipe 5, and the movable mold support member 9 is used to tighten the heat conduction pipe 5; the movable mold support member 9 is installed and inserted into the mold cavity of the movable mold 11, and the fixed mold support member 10 is installed and inserted into the mold cavity of the movable mold 11. The fixed mold 12 is provided with an injection port 13 for injecting semi-solid magnesium alloy slurry. During die casting, two fixed mold supports 10 are installed in the mold cavity of the fixed mold 12, and then the heat pipe 5 is clamped into the fixed mold support 10, and the movable mold support 9 is installed on the movable mold 11. After the mold is closed, the movable mold support 9 supports the heat pipe 5. The fixed mold support 10 and the movable mold support 9 tightly clamp the heat pipe 5 in the mold. When the semi-solid magnesium alloy slurry is quickly filled into the mold, the impact force will not cause the heat pipe 5 to move or deviate.

[0033] Preferably, the fixed mold support 10 is provided with a clamping groove for clamping the heat pipe 5, and the heat pipe 5 can be clamped and fixed in the clamping groove to avoid the problem of the heat pipe falling off and shifting due to the shaking of the platform during mold closing; the movable mold support 9 is provided with a groove for tightening the heat pipe 5, and the groove is consistent with the surface of the heat pipe 5.

[0034] Preferably, the heat pipe 5 and the shell magnesium base plate 1 are suspended and tightly combined, and the movable mold support 9 and the fixed mold support 10 are made of the same magnesium alloy AZ91D as the heat dissipation shell, so that the support can be integrated into the semi-solid slurry; and the movable mold support 9 and the fixed mold support 10 are in a thin sheet structure, which is easier to be completely melted during the semi-solid slurry filling process, and after the support is melted, the heat pipe 5 and the shell magnesium base plate 1 are in contact without interruption, and no holes will remain in the support part, so that the entire heat pipe 5 is not exposed, thereby achieving the purpose of suspended inlay.

[0035] This embodiment also discloses a semi-solid die-casting process, based on the above die-casting mold, such as Figure 6 As shown, the process includes the following steps: Step 1: Design a movable mold support 9 and a fixed mold support 10 for fixing the heat pipe 5, and install them in the mold cavities of the movable mold 11 and the fixed mold 12 respectively; Step 2: preheating the heat conducting tube 5, and clamping and fixing the preheated heat conducting tube 5 on the fixed mold support 10; Step 3: The mold is closed, and the movable mold support 9 is pressed against the heat pipe 5 to fix it; Step 4: Inject the semi-solid magnesium alloy slurry into the mold cavity through the injection port 13. The fixed mold support 10 and the movable mold support 9 are melted into one with the semi-solid magnesium alloy slurry, and the fixed mold support 10 and the movable mold support 9 are automatically removed from the mold, so that the heat pipe 5 is suspended and embedded in the shell magnesium base plate 1. Step 5: After the casting cools down, open the mold and take out the heat dissipation shell.

[0036] After die casting according to the above operation, the magnesium alloy semi-solid photovoltaic inverter heat dissipation housing casting with the heat pipe 5 suspended and embedded is as follows. Figure 5 As shown, the heat pipe 5 is embedded in the magnesium base plate 1 of the housing and is not exposed. The heat pipe 5 and the magnesium base plate 1 are tightly combined, and there is no core support made of other materials around the heat pipe 5, so the heat pipe 5 is suspended and embedded. This photovoltaic inverter heat dissipation housing product with the suspended heat pipe 5 embedded has been assembled and tested by the Central Communication. The thermal conductivity meets the heat dissipation requirements of highly integrated IC devices, achieving the expected purpose. This provides an empirical basis for the design of lightweight and high heat transfer inverter heat dissipation housings in the photovoltaic energy storage field.

[0037] It can be seen from the above embodiments that a high thermal conductivity is desired during use of the semi-solid heat dissipation shell. However, due to the limitations of the alloy materials and processes of the heat dissipation shell in normal production, the thermal conductivity of the magnesium alloy semi-solid heat dissipation shell used is only 70-90w / mk. Therefore, the present application adopts a pre-embedded heat pipe 5 in the structural design to improve the heat conduction efficiency, that is, a heat pipe with a high thermal conductivity medium is pre-embedded in the heat dissipation shell, so that the local thermal conductivity of the shell can reach 800-1000w / mk, thereby improving the heat conduction efficiency of the heat dissipation shell.

[0038] Finally, it should be noted that in the description of the present invention, it should be noted that the terms "vertical", "up", "down", "horizontal", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limiting the present invention.

[0039] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art will be able to modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein with equivalents. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A magnesium alloy inverter heat dissipation housing, comprising at least a housing magnesium substrate (1) and a heat pipe (5), characterized in that: The heat conducting pipe (5) is installed at an internal position of the shell magnesium base plate (1); a mounting boss (2) is provided on the shell magnesium base plate (1); an IC electronic component (3) is mounted on the mounting boss (2) via a conductive adhesive (4); and the heat conducting pipe (5) is located near the mounting boss (2).

2. The magnesium alloy inverter heat dissipation housing according to claim 1, characterized in that: The heat conducting pipe (5) comprises a stainless steel shell (6) and a heat conducting medium (7) located inside the stainless steel shell (6).

3. The magnesium alloy inverter heat dissipation housing according to claim 2, characterized in that: The heat conducting pipe (5) is pre-buried in an internal position of the housing magnesium base plate (1) in a suspended embedded structure through a semi-solid die-casting process.

4. The magnesium alloy inverter heat dissipation housing according to claim 1, characterized in that: A plurality of heat sinks (8) are provided on the surface of the shell magnesium base plate (1).

5. A die-casting mold for producing a magnesium alloy inverter heat dissipation housing according to claim 4, characterized in that: include: A movable mold (11) and a fixed mold (12); surfaces of the movable mold (11) and the fixed mold (12) are both provided with a mold cavity that matches the shape of the heat dissipation shell; A movable mold support (9) and a fixed mold support (10), wherein the fixed mold support (10) is used to clamp and fix the heat conducting tube (5), and the movable mold support (9) is used to tighten the heat conducting tube (5); the movable mold support (9) is installed in the mold cavity of the movable mold (11), and the fixed mold support (10) is installed in the mold cavity of the fixed mold (12); The fixed mold (12) is provided with an injection port (13) for injecting semi-solid magnesium alloy slurry.

6. The die-casting mold according to claim 5, characterized in that: The fixed die support (10) is provided with a clamping groove for clamping the heat conducting tube (5), and the movable die support (9) is provided with a groove for tightening the heat conducting tube (5).

7. The die-casting mold according to claim 6, characterized in that: The movable die support (9) and the fixed die support (10) are both made of the same magnesium alloy AZ91D as the heat dissipation housing.

8. The die-casting mold according to claim 7, characterized in that: The movable die support member (9) and the fixed die support member (10) are in a thin sheet-like structure.

9. A semi-solid die-casting process, using a die-casting mold as claimed in claim 8, characterized in that: The following steps are involved: Step 1: Designing a movable mold support (9) and a fixed mold support (10) for fixing the heat pipe (5), and installing them in the mold cavities of the movable mold (11) and the fixed mold (12), respectively; Step 2: preheating the heat conducting tube (5), and clamping and fixing the preheated heat conducting tube (5) on the fixed mold support (10); Step 3: The mold is closed, and the movable mold support (9) is tightened and fixed against the heat pipe (5); Step 4: injecting the semi-solid magnesium alloy slurry into the mold cavity through the injection port (13), and the fixed mold support (10) and the movable mold support (9) are melted and cast into one body with the magnesium alloy semi-solid slurry, so as to achieve the purpose of suspending and embedding the heat pipe (5) in the shell magnesium base plate (1); Step 5: After the casting cools down, open the mold and take out the heat dissipation shell.

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