A heat dissipation structure for a 24V / 48V DC-DC converter

Abstract

The utility model provides a kind of 24V / 48V DCDC converter heat dissipation structure for vehicle, belong to vehicle-mounted electronics field. Including main casing, upper cover, power control integrated board, heat-conducting silica gel pad, fan module and external interface module. MOS in the power control integrated board adopts SMT welding process, heat transfer is carried out by PCB opening, the rest power device is welded in PCB bottom by wave-soldering, contact with main casing by heat-conducting silica gel pad, the bottom of main casing is divergent radiating fin, adopts die-casting integrated molding process, cooperate high heat transfer coefficient heat-conducting silica gel pad and power device heat is rapidly transferred to the surface of shell radiating fin, main casing is fixedly connected with other module by screw, fan in the fan module adopts down pressure type and carries out forced air cooling to the bottom radiating fin of main casing, fan module is connected with internal PCB by external interface module, the upper cover is auxiliary radiating.

Description

Technical Field

[0001] This utility model relates to the field of automotive electronics, and in particular to a 24V / 48V DC-DC converter. Background Technology

[0002] With the rapid growth of the automotive electronics market, traditional electrical systems can no longer meet the increasing demands of high-power electronic devices, leading to the widespread adoption of 48V power supply systems in recent years. Compared to traditional 12V or 24V power supply systems, 48V can significantly increase output power under the same current conditions, thereby driving high-power electronic devices such as air conditioners and motors.

[0003] However, due to cost considerations, traditional power supply systems have a large industrial chain and cost advantages, and many loads in the vehicle still require traditional power supply systems. Furthermore, this solution is unlikely to be replaced by a 48V power supply system for a considerable period. In the overall vehicle system, adding a 48V battery to operate high-power equipment is not only space-constrained but also significantly increases the overall vehicle cost. Therefore, to retain the original power supply system, a high-power DC-DC converter is needed to provide 48V power.

[0004] High-power 24V / 48V DC-DC converters require more sophisticated cooling systems to ensure stable output from their internal power components over extended periods. While air cooling offers less cooling capacity and may not meet airtightness requirements compared to liquid cooling, it is more flexible and reliable within the vehicle system because it doesn't require changes to the cooling circuit. Therefore, there is a pressing need for a 24V / 48V DC-DC converter with an excellent cooling structure that also meets the vehicle's protection rating requirements. Utility Model Content

[0005] To address the existing problems, this utility model provides a forced air-cooling structure for a 24V / 48V DC-DC converter, which can not only achieve long-term operation at full load of 3kW, but also meet the IP67 protection level requirements.

[0006] To achieve the above objectives, this utility model provides a heat dissipation structure for a 24V / 48V DC-DC converter, comprising an upper cover, a main housing, an integrated power control board, a thermally conductive silicone pad on the MOS, a fan module, and a fan connector module, characterized in that;

[0007] The upper cover is detachably fixed to the main housing by screws. The lower surface of the upper cover is thermally bonded to the LV-side MOS and HV-side MOS modules in the power control integrated board through the thermally conductive silicone pad on the MOS, which is used to conduct heat to the upper cover and dissipate heat through air convection.

[0008] The power control integrated board has a 24V rod inductor and a 48V rod inductor. The main housing has a first mounting slot and a second mounting slot for conformally wrapping the 24V rod inductor and the 48V rod inductor. The bottom of the main housing has an integrally formed radiating heat dissipation fin.

[0009] The main housing is further provided with a first mounting plane and a second mounting plane. The power control integrated board is installed on the inner cavity mounting surface of the main housing by screws. A MOS thermal conductive silicone pad, a capacitor thermal conductive silicone pad, a rod inductor thermal conductive silicone pad and a power inductor thermal conductive silicone pad are sequentially attached below it. Each thermal pad is in close contact with the first mounting plane and the second mounting plane on the main housing for heat conduction.

[0010] The bottom of the main housing is provided with die-cast divergent heat dissipation fins, and the center and corners are provided with a first mounting position and a second mounting position, which are used for the fixed installation of the fan and the fan connector base, respectively.

[0011] The fan connector base is fixed to the second mounting position at the bottom of the main housing by screws. Its mounting end is provided with a sealing ring groove, and a fan connector base sealing ring is provided in the sealing ring groove. A fan connector female end sealing ring is provided inside the fan connector female end.

[0012] Preferably, the lower surface of the upper cover is thermally bonded to the LV-side MOS and HV-side MOS modules in the power control integrated board via a thermally conductive silicone pad on the MOS, which is used to conduct heat to the upper cover and dissipate heat through air convection.

[0013] The main housing fins are divergent heat dissipation fins, which have a larger heat dissipation area than traditional unidirectional fins. Under the same static pressure fan conditions, the airflow is better, and the fins extend 4mm beyond the bottom of the housing and connect with the flange surface, resulting in higher overall rigidity and strength.

[0014] Preferably, the down-draft fan is fixedly connected to the first mounting position at the bottom of the main housing by screws. The first mounting position covers high heat-generating devices such as power inductors, rod inductors, and MOS modules. A 10mm high heat dissipation fin is reserved at the bottom of the fan and the bottom surface of the housing. Under targeted heat dissipation conditions, this not only increases the heat dissipation area but also effectively allows air circulation and faster heat exchange.

[0015] Preferably, a gap of approximately 10mm is reserved between the bottom of the fan and the main housing to allow for airflow and to prevent foreign objects from contacting the fan blades.

[0016] Preferably, the first and second mounting slots of the main housing are designed to mimic the appearance of the 24V rod inductor and the 48V rod inductor, respectively. The mimicry design can not only greatly increase the contact area between the thermal conductive silicone pad and the surface of the rod inductor, but also effectively improve the EMC anti-interference effect. In addition, the mimicry groove design can use potting heat dissipation process as an alternative solution to achieve a higher heat dissipation effect.

[0017] Preferably, the first mounting surface inside the main housing has nine 3mm thick die-cast integrated heat dissipation fins, which can effectively and quickly disperse and transfer the 30W heat loss from the 24V side to the bottom of the housing.

[0018] Preferably, the MOS module in the power control integrated board adopts SMT soldering process, and most of the heat is transferred to the main housing through heat exchange downward through the PCB opening. This solution is not only stable and reliable through SMT soldering, but also reduces the number of wave soldering times, optimizes the overall cost, and can also achieve double-sided heat dissipation by contacting the MOS module with the top cover through thermally conductive silicone pads.

[0019] Preferably, the fan connector base is provided with a sealing ring with a diameter of 1.8mm, and the internal wiring harness is provided with a potting groove. By filling the inside with waterproof elastic silicone material, the entire connector base fully meets the dustproof and waterproof requirements. The fan connector female end is provided with a sealing ring with a diameter of 1mm and a height of 6mm to achieve secondary protection, further preventing the internal terminals of the connector from getting damp and extending the service life.

[0020] Compared with existing technologies, the advantages of this invention are as follows: This invention increases the heat dissipation contact area by using the first and second mounting slots of the main housing to mimic the shape of the rod-type inductor. The MOS module in the integrated power control board is SMT-soldered onto the surface of the PCB with open holes. This not only offers cost advantages and stability but also improves heat transfer capacity through double-sided heat dissipation. Nine 3mm thick die-cast integrated heat dissipation fins on the first mounting surface effectively and quickly disperse the 30W heat loss from the 24V side to the bottom of the housing. Forced air cooling from the fan on the radiating heat dissipation fins at the bottom of the housing rapidly removes heat loss generated by the power devices. The fan connector base has a 1.8mm diameter sealing ring, and the internal wiring harness is filled with elastic silicone waterproof adhesive, ensuring the entire connector base meets dust and water resistance requirements. A 1.5mm diameter, 6mm high sealing ring is added inside the female end of the fan connector to achieve secondary protection. Through the above structural design, this 24V / 48V DC-DC converter can not only dissipate heat quickly and achieve long-term operation at full load of 3kW, but also meet the internal IP67 dust and water resistance requirements. Attached Figure Description

[0021] Figure 1This is an exploded three-dimensional structural diagram of the 24V / 48V DC-DC converter of this utility model;

[0022] Figure 2 This is a top view of the main shell structure of this utility model;

[0023] Figure 3 This is a cross-sectional view of the 24V / 48V DC-DC converter of this utility model;

[0024] Figure 4 This is a bottom view of the air-cooled heat dissipation structure of this utility model;

[0025] Figure 5 This is an exploded view of the fan sealing connection structure of this utility model;

[0026] In the diagram: 1. Top cover; 2. Power control integrated board; 3. External connector; 4. Thermal pad on MOSFET; 5. Thermal pad on power inductor; 6. Thermal pad on MOSFET; 7. Thermal pad on capacitor; 8. Thermal pad on rod inductor; 9. Main housing; 10. 24V fan; 11. Female fan connector; 12. Fan connector base; 13. Fan protective cover; 14. First mounting slot; 15. First mounting plane; 16. Second mounting plane; 17. Second mounting slot; 18. 3mm thick heat dissipation fins; 19. Diverging heat dissipation fins; 20. First mounting position; 21. Second mounting position; 22. Sealing ring on female fan connector; 23. Sealing ring on fan connector base. Detailed Implementation

[0027] To provide a clear and complete understanding of the scheme, structure, function, and purpose of this utility model, a detailed description of the heat dissipation structure of a 24V / 48V DC-DC converter will be provided below with reference to the accompanying drawings. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without inventive effort are within the scope of protection of this utility model.

[0028] Please see Figures 1 to 5 This utility model provides a technical solution: a heat dissipation structure for a 24V / 48V DC-DC converter, including an upper cover 1, a power control integrated board 2, an external connector 3, a thermally conductive silicone pad on the MOS 4, a thermally conductive silicone pad on the power inductor 5, a thermally conductive silicone pad on the lower MOS 6, a thermally conductive silicone pad on the capacitor 7, a thermally conductive silicone pad on the rod-type inductor 8, a main housing 9, a 24V fan 10, a female fan connector 11, a fan connector base 12, a fan protective cover 13, a first mounting groove 14, a first mounting plane 15, a second mounting plane 16, a second mounting groove 17, 3mm thick heat dissipation ribs 18, divergent heat dissipation fins 19, a first mounting position 20, a second mounting position 21, a sealing ring on the female fan connector 22, and a sealing ring on the fan connector base 23;

[0029] Figure 1 This is an exploded view of the 3D structure of a 24V / 48V DC-DC converter. The upper cover 1 is connected to the main housing 9 via detachable fixing screws. The 24V fan 10 and the fan connector base 12 are respectively connected to the bottom of the main housing 9 via detachable fixing screws. The 24V fan 10 is connected to the fan connector base 12 via a snap-fit ​​connection between the female end 11 of the fan connector and the fan connector base 12, and transmits electrical signals to the power control integrated board 2 via a wiring harness. The external connector 3 is a waterproof connector, fixedly connected to the main housing 9 for transmitting signals to the client and realizing power input and output. The thermally conductive silicone pads 4 on the MOS, 5 on the power inductor, 6 on the lower MOS, 7 on the capacitor, and 8 on the rod inductor are all high thermal conductivity silicone thermal pads with fabric, which not only have a thermal conductivity of up to 6W, making it easier to achieve rapid heat exchange, but are also not easily crushed. The fan guard 13 is used to protect the blades of the 24V fan 10 and is fixed to the fan surface with four detachable fixing screws.

[0030] Furthermore, Figure 2 This is a top view of the main housing structure of this utility model. The first mounting groove 14 and the second mounting groove 17 are respectively designed to mimic the appearance of the 24V rod inductor and the 48V rod inductor in the power control integrated board 2. The mimicry design can not only greatly increase the contact area between the thermal conductive silicone pad and the surface of the rod inductor, but also effectively improve the EMC anti-interference effect. The first mounting plane 15 and the second mounting plane 16 are press-fitted to the bottom of the PCB of the MOS module in the power control integrated board 2 through the thermal conductive silicone pad 6 under the MOS, thereby transferring most of the heat to the bottom surface of the main housing 9. The 3mm thick heat dissipation ribs 18 connect the first mounting plane 15 and the bottom of the main housing 9, which can effectively disperse and transfer the 30W heat loss generated by the 24V side MOS in the power control integrated board 2 to the bottom of the main housing 9.

[0031] Furthermore, Figure 3 This is a cross-sectional view of the 24V / 48V DC-DC converter of this utility model. In the upper cover 1 and the power control integrated board 2, the LV-side MOS and HV-side MOS modules respectively transfer the heat from the surface of the MOS module to the surface of the upper cover 1 through the thermal conductive silicone pad 4 on the MOS, and exchange heat with the air through the surface of the upper cover 1 to achieve auxiliary heat dissipation of the upper cover 1. The heat generated by the remaining MOS is transferred to the bottom of the main housing 9 through the thermal conductive silicone pad 6 under the MOS.

[0032] Furthermore, Figure 4This is a bottom view of the air-cooled heat dissipation structure of this utility model. The divergent heat dissipation fins 19 are die-cast integrally, which have a larger heat dissipation area than traditional unidirectional fins. Under the same static pressure fan conditions, the air flow is better. The fins extend 4mm beyond the bottom of the shell and are connected to the flange surface, resulting in higher overall rigidity and strength. The center and corners of the divergent heat dissipation fins 19 are reserved with a first mounting position 20 and a second mounting position 21.

[0033] Figure 4 The 24V fan 10 and the fan guard 13 are fixed to the first mounting position 20 at the bottom of the main housing 9 by M4*35 detachable fixing screws. The fan connector base 12 is fixed to the second mounting position 21 at the bottom of the main housing 9 by M4*10 detachable fixing screws. The 24V fan 10 is connected to the fan connector base 12 by a snap-fit ​​engagement through the female end 11 of the fan connector, and transmits electrical signals to the power control integrated board 2 through a wire harness.

[0034] Furthermore, Figure 5 This is an exploded view of the fan sealing connection structure of this utility model. The mounting end face of the fan connector base 12 is provided with a 2.0mm wide sealing ring groove that is glued to the fan connector base sealing ring 23. The first mounting position 20 at the bottom of the main housing 9 is machined by CNC machining to make the surface smoother. The fan connector base 12 is filled with elastic waterproof adhesive, and the fan connector female end 11 is provided with a fan connector female end sealing ring 22. The sealing ring is made of EPDM material, which has a higher compression rate. Based on the above solutions, a secondary protection effect is achieved, thereby meeting the IP67 dustproof protection level requirement.

[0035] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A heat dissipation structure for a 24V / 48V DC-DC converter, comprising: The components are: top cover (1), main housing (9), power control integrated board (2), thermal conductive silicone pad on MOS (4), fan module and fan connector module, characterized in that: The upper cover (1) is detachably fixed to the main housing (9) by screws. The lower surface of the upper cover (1) is thermally bonded to the LV side MOS and HV side MOS modules in the power control integrated board (2) through the MOS thermal conductive silicone pad (4) on the MOS, so as to realize the conduction of heat to the upper cover (1) and air convection heat dissipation. The power control integrated board (2) has a 24V rod inductor and a 48V rod inductor. The main housing (9) has a first mounting groove (14) and a second mounting groove (17) for conformally wrapping the 24V rod inductor and the 48V rod inductor. The bottom of the main housing (9) has an integrally formed radiating heat dissipation fin (19). The main housing (9) is further provided with a first mounting plane (15) and a second mounting plane (16). The power control integrated board (2) is installed on the inner cavity mounting surface of the main housing (9) by screws. Below it, a MOS thermal conductive silicone pad (6), a capacitor thermal conductive silicone pad (7), a rod inductor thermal conductive silicone pad (8), and a power inductor thermal conductive silicone pad (5) are attached in sequence. Each thermal pad is in close contact with the first mounting plane (15) and the second mounting plane (16) on the main housing (9) for heat conduction. The bottom of the main housing (9) is provided with a die-cast radiating heat dissipation fin (19), and a first mounting position (20) and a second mounting position (21) are provided at its center and corner, respectively for the fixed installation of the fan and the fan connector base (12); The fan connector base (12) is fixed to the second mounting position (21) at the bottom of the main housing (9) by screws. Its mounting end is provided with a sealing ring groove, and a sealing ring of the fan connector base (12) is provided in the sealing ring groove. A sealing ring of the fan connector female end (11) is provided inside the fan connector female end (11).

2. The heat dissipation structure for a 24V / 48V DC-DC converter according to claim 1, characterized in that: It also includes heat dissipation ribs, which connect the first mounting plane (15) to the bottom of the main housing (9) and can quickly disperse and transfer the 30W heat loss generated by the 24V side MOS in the power control integrated board (2) to the bottom of the main housing (9).

3. The heat dissipation structure for a 24V / 48V DC-DC converter according to claim 1, characterized in that: The fan module is connected to the fan connector base (12) by a snap-fit ​​connection between the female end (11) of the fan connector and the base (12), and transmits electrical signals to the power control integrated board (2) through a wire harness.

4. The heat dissipation structure for a 24V / 48V DC-DC converter according to claim 1, characterized in that: A fan guard (13) is installed on the top of the fan by screws. A gap of about 10mm is reserved between the bottom of the fan and the main housing (9) for airflow and to prevent foreign objects from contacting the fan blades.

5. A heat dissipation structure for a 24V / 48V DC-DC converter according to claim 1, characterized in that: The fan is fixed above the first mounting position (20) by screws, and its air outlet faces the radiating heat dissipation fins (19) for downward air cooling.

6. The heat dissipation structure for a 24V / 48V DC-DC converter according to claim 1, characterized in that: The fan module is connected to the fan connector base (12) by a snap-fit ​​connection between the female end (11) of the fan connector and the base (12), and transmits electrical signals to the power control integrated board (2) through a wire harness.

7. A heat dissipation structure for a 24V / 48V DC-DC converter according to claim 1, characterized in that: The fan connector base (12) is filled with elastic waterproof adhesive, and the sealing rings of the fan connector female end (11) and the fan connector base (12) are both made of EPDM material.

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