A variable frequency refrigerator controller

Abstract

The utility model relates to a kind of frequency conversion refrigerator controller, to solve the technical problem of low heat dissipation efficiency, poor sealing of frequency conversion refrigerator controller in prior art.This controller includes the composite shell of the integral injection molding of plastic part and metal heat dissipation part, and the double-sided printed circuit board being set in shell body.Integrated with microprocessor, power module and the complete control circuit of other components on circuit board, the core heat-generating power element is installed in the lower surface of circuit board, and is heat-conducting connection with the inner mounting surface of metal heat dissipation part.When using, the heat generated by power element can be directly and quickly conducted to the metal heat dissipation part exposed in external environment, to realize efficient heat dissipation.The utility model integrates heat dissipation structure and shell structure, and optimizes circuit board layout, not only greatly improves heat dissipation efficiency, but also realizes the shell structure of full sealing, while structure is more compact, significantly enhances the reliability of long-term operation of frequency conversion refrigerator controller.

Description

Technical Field

[0001] This utility model relates to the field of variable frequency refrigerator controllers, and specifically to a controller with an embedded heat dissipation structure for variable frequency refrigerators. Background Technology

[0002] With increasing demands for energy conservation and environmental protection, inverter refrigerators using variable frequency compressors have become the mainstream in the market. Unlike ordinary refrigerators that use relays to control the compressor's start and stop, inverter refrigerators require a high-power inverter module (such as an IPM / IGBT module) as the core controller to continuously and smoothly control the compressor's speed. During this process, the inverter module generates a large and concentrated amount of heat. If this heat cannot be dissipated in time, it will cause the controller to reduce its frequency for protection, affecting the cooling effect and, in severe cases, even burning out power components and causing refrigerator malfunctions. Existing inverter refrigerator controllers typically use a fully enclosed plastic casing. Inside, the heat-generating inverter module is fixed to a separate aluminum heat sink by screws on the circuit board. To dissipate the heat, numerous heat dissipation grilles must be created on the plastic casing. This design has the following drawbacks:

[0003] (1) Low heat dissipation efficiency. The heat needs to heat the heat sink first, then heat the air inside the shell, and finally dissipate through the grille via natural air convection. The heat transfer chain is long and inefficient.

[0004] (2) Poor sealing performance. The presence of heat dissipation grilles makes it easy for dust and moisture to enter the controller, corroding the circuit board and seriously affecting the reliability and service life of the product.

[0005] (3) The structure is bulky. The independent heat sink and the space reserved for air convection occupy a lot of volume, which is not conducive to the miniaturization design of the controller.

[0006] Therefore, how to provide an efficient, reliable and compact heat dissipation solution for variable frequency refrigerator controllers has become a technical problem that urgently needs to be solved in this field. Utility Model Content

[0007] The technical problem to be solved by this utility model is to address the issues of low heat dissipation efficiency, poor sealing, and bulky structure of existing variable frequency refrigerator controllers, and to provide a variable frequency refrigerator controller.

[0008] To solve the above-mentioned technical problems, this variable frequency refrigerator controller includes a housing and a circuit board disposed within the housing. The circuit board is provided with a power element that generates heat. The housing is characterized in that: the housing is a composite housing, which is integrally injection molded from a plastic part and a metal heat dissipation part. The metal heat dissipation part constitutes at least a portion of the outer wall of the housing and has an inner mounting surface facing the inside of the housing and an outer heat dissipation surface exposed to the outside of the housing; wherein, the heat-generating surface of the power element is in contact with the inner mounting surface of the metal heat dissipation part for thermal conduction, so as to directly conduct the heat generated by the power element to the outer heat dissipation surface.

[0009] Furthermore, the circuit board is a double-sided printed circuit board, and the power components are mounted on the lower surface of the circuit board facing the inner mounting surface in a recessed or reverse-mount manner.

[0010] Furthermore, the circuit board also integrates a microprocessor, a power module, a signal processing circuit, and a drive circuit; the microprocessor is electrically connected to the power module, the signal processing circuit, and the drive circuit, respectively, and the drive circuit is used to drive the power element to work according to the instructions of the microprocessor.

[0011] Furthermore, the metal heat dissipation part is made of aluminum alloy; a thermally conductive interface material is filled between the power element and the inner mounting surface of the metal heat dissipation part.

[0012] Furthermore, the plastic portion of the housing is provided with positioning posts for positioning the circuit board, and the circuit board is provided with corresponding positioning holes that cooperate with the positioning posts; the circuit board is fixed to the housing by fixing screws, and the fixing screws are provided to provide pre-tightening pressure for the contact between the power component and the metal heat dissipation part when tightened.

[0013] This utility model discloses a variable frequency refrigerator controller, which overcomes the problems of low heat dissipation efficiency, poor sealing, and bulky structure of existing variable frequency refrigerator controllers. By integrating the heat dissipation structure with the housing structure and optimizing the circuit board layout, it not only significantly improves the heat dissipation efficiency but also achieves a fully sealed housing structure. At the same time, the structure is more compact, which significantly enhances the long-term reliability of the variable frequency refrigerator controller. Attached Figure Description

[0014] The following description, in conjunction with the accompanying drawings, further illustrates a variable frequency refrigerator controller according to this utility model:

[0015] Figure 1 This is a three-dimensional structural diagram of the inverter refrigerator controller;

[0016] Figure 2 yes Figure 1 Front view plan structural diagram;

[0017] Figure 3 yes Figure 2 A schematic diagram of the left-side planar structure;

[0018] Figure 4 yes Figure 2 Sectional view along axis AA;

[0019] Figure 5 yes Figure 3 BB-direction sectional view;

[0020] Figure 6 yes Figure 5 Exploded structure diagram;

[0021] Figure 7 This is a block diagram of the electrical connections of this variable frequency refrigerator controller.

[0022] In the picture:

[0023] 10-Outer shell; 11-Plastic part; 12-Metal heat dissipation part; 111-Positioning post; 121-Inner mounting surface; 122-Outer heat dissipation surface;

[0024] 20-Circuit board; 21-Power component; 22-Positioning hole; 23-Microprocessor; 24-Power module; 25-Signal processing circuit; 26-Drive circuit;

[0025] 30 - Fixing screw;

[0026] 40 - Thermally conductive interface material. Detailed Implementation

[0027] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in this utility model can be understood according to the specific circumstances.

[0028] In the description of this utility model, it should be understood that the terms "left", "right", "front", "rear", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0029] The present invention will be further described below with specific embodiments, but the scope of protection of the present invention is not limited to the following embodiments.

[0030] Implementation method 1: such as Figures 1 to 6 As shown, this inverter refrigerator controller includes a housing 10 and a circuit board 20 disposed within the housing 10. The circuit board 20 is provided with a power element 21 that generates heat (usually an inverter module IPM or IGBT). The housing 10 is a composite housing, which is not made of a single material, but is integrally injection molded from a plastic part 11 and a metal heat dissipation part 12. Specifically, the pre-formed metal heat dissipation part 12 is pre-placed in the injection mold, and then the plastic part is injection molded, so that the plastic part 11 is firmly bonded to the edge of the metal heat dissipation part 12 or a pre-set bonding structure during the solidification process, forming a seamless whole. The metal heat dissipation part 12 plays a dual role in the composite housing 10. On the one hand, it has a flat inner mounting surface 121 facing the inside of the housing, which is specifically used as the mounting reference and heat conduction interface for the power element 21. On the other hand, it has an external heat dissipation surface 122 directly exposed to the external environment of the housing, forming part of the outer wall of the composite housing 10; wherein, the heating surface of the power element 21 is in contact with the inner mounting surface 121 of the metal heat dissipation part 12 for thermal conduction, so as to directly conduct the heat generated by the power element 21 to the external heat dissipation surface. This controller adopts a metal-plastic composite housing design. The heat sink is no longer an independent assembly, but becomes part of the housing as the skeleton and skin, realized by an integral injection molding process. This structural design changes the traditional controller's indirect heat dissipation mode. Heat no longer needs to be transferred through internal air convection, but is directly and quickly conducted from the heat source (power element) to the exposed metal housing, achieving the shortest heat dissipation path. This solves the technical pain points of traditional variable frequency refrigerator controllers, which suffer from low heat dissipation efficiency, poor sealing, and large internal space occupation due to the use of closed plastic housings with heat dissipation grilles, and provides efficient, reliable and compact heat dissipation guarantee for high-power variable frequency modules.

[0031] Implementation method 2: such as Figures 4 to 6As shown, the circuit board 20 of this variable frequency refrigerator controller is a double-sided printed circuit board. Most conventional electronic components are arranged on the upper surface of the circuit board 20, while the power element 21 (specifically, an intelligent power module IPM in this embodiment), which serves as the main heat source, is soldered to the lower surface of the circuit board 20, i.e., the side facing the metal heat sink 12, using either a recessed mounting or reverse mounting method. The power element 21 achieves a tight thermally conductive connection with the inner mounting surface of the metal heat sink 12 through its heating surface. By using a double-sided PCB and directly attaching the power element to the lower surface of the PCB, a physical basis is provided for subsequent screw pressure from above, ensuring the entire assembly logic is fully valid and providing crucial support for the feasibility of the solution. To eliminate microscopic air gaps between the contact surfaces and reduce contact thermal resistance, the metal heat sink 12 is made of aluminum alloy; a thermally conductive interface material 40 is filled between the power element 21 and the inner mounting surface of the metal heat sink 12. The material of the metal heat sink has been optimized; aluminum alloy has the advantages of being lightweight, having good thermal conductivity, moderate cost, and being easy to process and form, making it an ideal material choice for realizing this technical solution. By filling the microscopic air gaps between the power component surface and the metal mounting surface with thermally conductive interface materials (such as thermal grease or thermal pads), air, a poor conductor of heat, is eliminated, ensuring 100% tight contact between the two at the microscopic level. This maximizes thermal conductivity and guarantees unobstructed heat transfer channels. This further improves the efficiency of heat transfer from the heat source to the heat sink, a necessary technical guarantee for achieving efficient heat dissipation. The remaining structures and components are as described in Embodiment 1 and will not be repeated.

[0032] Implementation method 3: such as Figure 7 As shown, the circuit board 20 of this variable frequency refrigerator controller also integrates a microprocessor 23 as the main controller, a power supply module 24 providing a stable operating voltage for the entire system, a signal processing circuit 25 for receiving and processing signals from internal temperature sensors and other sources, and a drive circuit 26 for receiving control signals from the microprocessor 23 and generating drive signals. The microprocessor 23 is electrically connected to the power supply module 24, the signal processing circuit 25, and the drive circuit 26. The processor 23, through its internal program logic, controls the switching frequency and conduction state of the power element 21 via the drive circuit 26 based on the temperature information fed back by the signal processing circuit 25. The drive circuit 26 drives the power element 21 to operate according to the instructions of the microprocessor 23. This precisely adjusts the compressor speed, achieving variable frequency control. This controller uses a microprocessor as the control core, coordinating various functional modules to ultimately drive the power element, forming a complete closed-loop control logic and achieving the integrity of the technical solution. The remaining structures and components are as described in Embodiment 1 and will not be repeated.

[0033] Implementation method 4: such as Figures 4 to 6As shown, the plastic part 11 of the outer casing 10 of this inverter refrigerator controller is provided with positioning posts 111 for positioning the circuit board 20. The circuit board 20 is provided with positioning holes 22 that cooperate with the positioning posts 111. The circuit board 20 is fixed to the outer casing 10 by fixing screws 30. The fixing screws 30 provide pre-tightening pressure for the contact between the power component 21 and the metal heat sink 12 when tightened. This ensures the accuracy and consistency of assembly in mass production. As a foolproof structure for internal assembly, during assembly, workers only need to align the positioning holes of the circuit board with the positioning posts on the outer casing to achieve quick and accurate positioning of the circuit board, ensuring that the position of the power component on each product corresponds precisely to the position of the metal heat sink. This solves the problem of poor contact between the power component and the heat sink surface due to assembly errors in mass production, which affects the heat dissipation effect and improves production efficiency and product consistency. The fixing screws not only play a mechanical fixing role, but more importantly, their tightening force is transmitted through the circuit board, pressing the power component tightly onto the metal heat sink with a constant pressure, further ensuring the tightness of the contact between the two. By using a thermally conductive interface material and applying pre-tightening pressure, the contact thermal resistance is minimized, ensuring the reliability of the thermally conductive connection during long-term operation and preventing loosening of the contact due to vibration or other reasons. The remaining structures and components are as described in Embodiment 1 and will not be repeated.

[0034] During assembly: First, apply an appropriate amount of thermal interface material 40 (such as thermal grease) to the inner mounting surface 121 of the metal heat sink 12. Then, place the circuit board 20, with all components already mounted, into the plastic part 11 of the composite housing 10 after aligning its positioning holes 22 with the positioning posts 111. At this point, the power component 21 located on the lower surface of the circuit board 20 will sit precisely on the thermal interface material 40. Finally, use a fixing screw 30 to pass through the upper surface of the circuit board 20 and screw it into the screw post of the plastic part 11. As the screw 30 is tightened, it pulls the entire circuit board 20 downwards, thereby generating a stable and uniform preload pressure that firmly presses the power component 21 onto the metal heat sink 12, achieving the lowest thermal resistance and the most reliable thermal connection.

[0035] During operation: When the inverter refrigerator controller is working, the power element 21 generates a large amount of heat due to driving the compressor. This heat is efficiently conducted through the thermal interface material 40 to the metal heat dissipation part 12, which is in close contact with it. Since the metal heat dissipation part 12 is itself part of the casing, the heat reaches the outer surface of the controller, i.e., the external heat dissipation surface, with almost no delay. Typically, the refrigerator controller is installed near the compressor at the back of the refrigerator, where there is a fan airflow for cooling the compressor and condenser. In this solution, the exposed external heat dissipation surface can make full use of this readily available forced convection environment to quickly dissipate heat into the surrounding air, thereby ensuring that the power element 21 always operates within a safe temperature range, guaranteeing the stable and efficient operation of the inverter refrigerator.

[0036] This inverter refrigerator controller integrates the heat dissipation structure with the housing structure and optimizes the circuit board layout, significantly improving heat dissipation efficiency and achieving a fully sealed housing structure. Furthermore, its more compact structure significantly enhances the long-term reliability of the inverter refrigerator controller. Specifically,

[0037] (1) High heat dissipation efficiency: By integrating the metal heat dissipation part with the plastic shell, the heat of the power component can be directly conducted to the exposed metal outer wall, realizing the "direct exhaust" of heat. The heat dissipation path is the shortest and the efficiency is much higher than the traditional internal air convection heat dissipation method.

[0038] (2) Good sealing: Since the heat dissipation function is undertaken by the shell itself, there is no need to open any heat dissipation grilles on the shell, realizing a fully sealed structure, effectively preventing the intrusion of dust and moisture, and greatly improving the reliability and environmental adaptability of the product.

[0039] (3) Compact structure: The internal independent heat sink and air flow channel are eliminated, which greatly saves internal space and allows the controller to be designed to be thinner and lighter, which is in line with the development trend of miniaturization of home appliances.

[0040] The above description illustrates the main features, basic principles, and advantages of this utility model. It will be apparent to those skilled in the art that this utility model is not limited to the details of the exemplary embodiments or examples described above, and that it can be implemented in other specific forms without departing from the spirit or basic characteristics of this utility model. Therefore, the above embodiments or examples should be considered exemplary and not restrictive. The scope of this utility model is defined by the appended claims rather than the foregoing description, and therefore all variations falling within the meaning and scope of equivalents of the claims are intended to be included within this utility model. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0041] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A variable frequency refrigerator controller, comprising a housing (10) and a circuit board (20) disposed within the housing (10), wherein the circuit board (20) is provided with a power element (21) for generating heat, characterized in that: The outer casing (10) is a composite casing, which is integrally injection molded from a plastic part (11) and a metal heat dissipation part (12). The metal heat dissipation part (12) constitutes at least a portion of the outer wall of the outer casing (10) and has an inner mounting surface (121) facing the inside of the casing and an outer heat dissipation surface (122) exposed to the outside of the casing; wherein, The heating surface of the power element (21) is thermally connected to the inner mounting surface (121) of the metal heat dissipation part (12) to directly conduct the heat generated by the power element (21) to the outer heat dissipation surface.

2. The variable frequency refrigerator controller according to claim 1, characterized in that: The circuit board (20) is a double-sided printed circuit board, and the power component (21) is mounted on the lower surface of the circuit board (20) facing the inner mounting surface (121) in a recessed or reverse mounting manner.

3. The variable frequency refrigerator controller according to claim 2, characterized in that: The circuit board (20) also integrates a microprocessor (23), a power module (24), a signal processing circuit (25), and a drive circuit (26); the microprocessor (23) is electrically connected to the power module (24), the signal processing circuit (25), and the drive circuit (26), respectively, and the drive circuit (26) is used to drive the power element (21) to work according to the instructions of the microprocessor (23).

4. The variable frequency refrigerator controller according to claim 3, characterized in that: The metal heat dissipation part (12) is made of aluminum alloy; the inner mounting surface of the power element (21) and the metal heat dissipation part (12) is filled with a thermally conductive interface material (40).

5. The variable frequency refrigerator controller according to claim 4, characterized in that: The plastic part (11) of the outer casing (10) is provided with a positioning post (111) for positioning the circuit board (20), and the circuit board (20) is provided with a positioning hole (22) that cooperates with the positioning post (111); the circuit board (20) is fixed to the outer casing (10) by a fixing screw (30), and the fixing screw (30) is provided to provide pre-tightening pressure for the contact between the power element (21) and the metal heat dissipation part (12) when tightened.

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