Efficient heat dissipation switching power supply with internal and external circulation isolation air duct

Abstract

The utility model discloses an efficient heat dissipation switching power supply with an internal and external circulation isolation air duct, which comprises an outer shell, an inner shell, a PCBA (Printed Circuit Board Assembly) power board, a magnetic device, a heat dissipation aluminum frame, a power MOS (Metal Oxide Semiconductor) tube, an internal circulation fan, an external circulation fan and a waterproof joint, the PCBA power board forms an inner circulation air channel with the gap between the PCBA power board and the lower end wall of the first radiator and the gap between the PCBA power board and the upper end wall of the lower sealing plate, the other end wall of the outer shell is provided with a plurality of air outlet holes, and the air inlet, the gap between every two adjacent cooling fins and the air outlet holes form an outer circulation air channel. According to the utility model, the internal circulation air channel and the external circulation air channel can be isolated from each other independently, heat of the power device can be uniformly, efficiently and rapidly dissipated to the external environment, large-scale automatic production can be realized, and the heat dissipation efficiency can reach the effect of traditional air cooling; and internal components of the power supply module are completely isolated from external air and dust, so that the service life of the switching power supply is greatly prolonged.

Description

Technical Field

[0001] The utility model relates to the technical field of switching power supplies, in particular to a high-efficiency heat dissipation switching power supply with internal and external circulation isolation air ducts. Background Art

[0002] The switching power supply works in a high-voltage switching state. Due to the effect of the fan, harmful substances such as insects, dust, salt spray, etc. in the environment will continuously enter the power supply and accumulate in different positions. The long-term accumulated foreign matter (dust, salt spray, insects, etc.) will absorb moisture in the air and become conductive substances (some foreign matter itself is conductive material). When these substances short-circuit different conductors inside the power supply, the power supply will fail.

[0003] There are many ways to solve this problem, among which designing a power supply that meets IP65 is a common method for pursuing a long life power supply. A power supply that meets IP65 can completely isolate the internal components from the use environment, and can prevent the internal components from being short-circuited by foreign objects in the environment and causing power failure.

[0004] The power of traditional IP65 power supplies is generally within 5KW, with a few hundred watts to a few kilowatts. They use a sealed casing and have no fan, and are generally large in size. However, with the development of power supply needs for charging piles and industrial occasions (especially dirty environments), the demand for high-power IP65 power supplies (such as 30KW) is increasing. If such a high-power power supply uses the traditional IP65 method, its size, weight and cost will be unacceptable.

[0005] Existing module power solutions that meet IP65 include: Figure 1 As shown in the figure, the power switch tube and electromagnetic components are welded on the back and top surface of the power board PCB respectively; then the power MOS tube is mounted in the shell through screws, pressure plates and insulating parts; the electromagnetic components transfer heat to the aluminum shell through thermal conductive silicone. After the internal assembly and sealing of the shell, it meets the IP65 protection level, and the heat generated by the internal power devices is removed by natural heat dissipation outside the shell.

[0006] There are two options for the design of the aluminum shell. One is that the upper cover is designed to be U-shaped (cross-section) cast aluminum as shown in the figure below, and the bottom is made of cast aluminum or aluminum profiles, with rubber pads or glue to achieve sealing and heat dissipation; the other is the other way around, the lower part is designed to be U-shaped (cross-section) cast aluminum, and the upper part is made of cast aluminum or aluminum profiles to achieve sealing and heat dissipation.

[0007] The traditional IP65 power module is a natural cooling module. The power device is completely sealed in an aluminum shell. The main power devices on the power board PCBA are directly or indirectly mounted on the inner wall of the aluminum shell through thermal conductive materials. The aluminum shell is used to dissipate the heat generated by the power device to the external environment through conduction and natural convection. This is a traditional passive heat dissipation method with very low heat dissipation efficiency. Its heat dissipation capacity is closely related to the heat dissipation area. When the heat consumption of the whole machine is very large, a huge heat sink is needed to solve the heat dissipation problem.

[0008] In addition, in traditional natural cooling modules, most of the plug-in components are on the upper surface of the PCB, but the power switch tube must be installed on the back of the PCB in order to attach to the inner wall of the aluminum shell for heat dissipation. This results in plug-in components on both sides of the PCB, and the wave soldering process cannot be used to complete the automated soldering of the plug-in components on both sides. Generally, the number of power switch tubes is much less than the number of components on the upper surface of the PCB, so manual soldering of the power switch tubes is generally chosen.

[0009] There are two ways to assemble at this time. One is to assemble after welding the power switch tube, and the other is to weld the power switch tube after assembly. The first solution is simple in PCBA processing, but the power switch tube is subjected to stress due to unavoidable assembly tolerance (which will bring hidden dangers to the long-term reliability of power components); the second solution can solve the assembly tolerance problem, but one is that the assembly is troublesome (first insert the power switch tube into the corresponding position, and then put it into the shell. The power switch tube is easy to fall off during the process of putting it into the shell; and the power components are easy to twist when screwing, which will cause insulation problems). The second is to weld after assembly, which is a large workload and easy to bring quality risks (static problems, cleaning problems, etc.).

[0010] To sum up, no matter how it is assembled, it will bring many problems.

[0011] Therefore, an IP65 heat dissipation solution for a high-power switching power supply with high efficiency heat dissipation and internal and external circulation isolation air ducts is proposed. Utility Model Content

[0012] The main purpose of the utility model is to propose a high-efficiency heat dissipation switching power supply with internal and external circulation isolation air ducts, aiming to solve the technical problems of low heat dissipation efficiency of existing switching power supplies, inability to use wave soldering technology to complete automatic soldering of double-sided plug-in components, requiring manual soldering, high labor intensity and low efficiency.

[0013] To achieve the above-mentioned purpose, the utility model proposes a high-efficiency heat dissipation switching power supply with an internal and external circulation isolation air duct, comprising an outer shell, an inner shell, a PCBA power board, a magnetic device, a heat dissipation aluminum frame, a power MOS tube, an internal circulation fan, an external circulation fan and a waterproof joint, wherein the inner shell is arranged in the outer shell, the outer shell comprises a bottom shell and an upper cover plate, the upper cover is sealed and arranged at the upper end of the bottom shell, the inner shell comprises a first radiator, a second radiator, a third radiator and a lower sealing plate, the second radiator and the third radiator are respectively arranged on both sides of the lower end wall of the first radiator, The lower end wall of the first radiator and the inner side walls of the second radiator and the third radiator are enclosed to form a receiving groove, the lower sealing plate is closed and arranged at the lower end of the receiving groove to form an inner circulation sealed cavity, one PCBA power board is provided, the PCBA power board is arranged in the receiving groove, the heat dissipation aluminum frame is arranged at the upper end of the PCBA power board, the upper end wall of the heat dissipation aluminum frame is fixedly connected to the lower end wall of the first radiator through a thermally conductive insulating film or a ceramic substrate, the magnetic device is arranged in the heat dissipation aluminum frame, and the magnetic device is fixedly connected to the heat dissipation aluminum frame, forming a heat dissipation ... The outer side walls of the power MOS tube are respectively fixedly connected to the inner side walls of the second radiator and the third radiator, and the lower end pins of the magnetic device and the power MOS tube are fixedly connected to the upper end wall of the PCBA power board by welding. Both ends of the PCBA power board are respectively spaced apart from the end walls of the lower sealing plate, and the PCBA power board is respectively spaced apart from the lower end wall of the first radiator and the upper end wall of the lower sealing plate. The internal circulation fan is arranged in the middle of one end of the PCBA power board, and the PCBA power board is respectively spaced apart from the lower end wall of the first radiator. The gap between the wall and the upper end wall of the lower cover plate forms an internal circulation air duct, the upper end wall of the first radiator and the outer side walls of the second radiator and the third radiator are respectively provided with a plurality of heat sinks at intervals, one end wall of the outer shell is recessed with at least 3 air inlets, the air inlets are respectively arranged on the outside of the heat sinks, the external circulation fans are respectively detachably arranged on the inner sides of the air inlets, the other end wall of the outer shell is provided with a plurality of air outlets, the air inlets, the gaps between two adjacent heat sinks and the air outlets form an external circulation air duct, and the waterproof joints are respectively arranged on the end wall of the lower cover plate.

[0014] Optionally, the upper end wall of the first radiator is arranged in a planar structure, the outer side walls of the second radiator and the third radiator are respectively provided with a plurality of cooling fins at intervals, two external circulation fans are provided, the air inlets are respectively arranged on both sides of an end wall of the outer shell, and the external circulation fans are respectively arranged on the inner side of the air inlets.

[0015] Optionally, two PCBA power boards are provided, and the PCBA power boards are arranged side by side in the accommodating groove. The two PCBA power boards are fixedly connected by a copper bus, a wire or a PCBA board. A partition is protruded between the two PCBA power boards, and the upper end wall of the partition abuts the lower end wall of the first radiator. Both ends of the partition are spaced apart and connected to the end wall of the lower sealing plate. The internal circulation fan is located on one side of the partition, and the partition forms an internal circulation air duct with the gap between the inner side walls of the second radiator and the third radiator.

[0016] Optionally, there is one external circulation fan, the outer wall of the second radiator is arranged in a planar structure, and a plurality of heat sinks are protruding from the outer wall of the third radiator at intervals, or the outer wall of the second radiator is arranged in a planar structure, and a plurality of heat sinks are protruding from the outer wall of the third radiator at intervals, and the air inlet is respectively arranged on one side of one end wall of the outer shell, the air inlet is located on the inner side of the heat sink, and the external circulation fans are respectively arranged on the inner side of the air inlet.

[0017] Optionally, the outer shell and the inner shell are both made of aluminum alloy.

[0018] Optionally, the protection levels of the outer shell and the inner shell are both IP65.

[0019] Optionally, the external circulation fan is a waterproof fan.

[0020] Optionally, the rotation speed of the internal circulation fan is lower than 75% of its maximum rotation speed.

[0021] Optionally, a plurality of heat sinks are protruded at intervals on both side walls of the heat dissipation aluminum frame.

[0022] Optionally, a waterproof rubber strip is provided at the joints between the first radiator, the second radiator and the third radiator, and at the joints between the first radiator, the second radiator and the third radiator and the lower sealing plate, so that the inner circulation air duct is completely isolated from the outer circulation air duct to meet the IP65 requirements.

[0023] The technical solution of the utility model has the following beneficial effects:

[0024] 1. The internal circulation air duct is isolated from the outside world and can meet the IP65 protection level. The internal circulation air duct can be divided into upper and lower air ducts by PCBA power boards, or it can be divided into left and right air ducts by two PCBA power boards, partitions and internal circulation fans arranged side by side;

[0025] 2. After the first heat sink, the second heat sink and the third heat sink are assembled into a whole, they are respectively assembled with the power device, and then the power device is welded to the PCBA power board as a whole by means of plug-in. This solution can meet the factory economy and mass production; at the same time, this assembly solution can also eliminate the assembly stress of the power device pins, thereby improving the long-term working reliability of the switching power supply module;

[0026] 3. The first radiator can be equipped with a fan and a heat sink for active heat dissipation according to the layout requirements of the PCBA power board, or it can be equipped with no fan and heat sink for passive and natural heat dissipation;

[0027] 4. The second and third radiators can be equipped with fans and heat sinks for active heat dissipation or without fans and heat sinks for passive and natural heat dissipation according to the layout requirements of the PCBA power board;

[0028] 5. The external circulation air duct is located on both sides and the top (or bottom) of the PCBA power board where the product needs to dissipate heat, and will not be located in the middle of the PCBA;

[0029] 6. The power devices that need heat dissipation are located at the edge of the PCBA power board with the heat dissipation surface facing outward to facilitate heat transfer to the radiator;

[0030] 7. The external circulation fan uses a waterproof fan, and the corresponding connector uses a waterproof connector;

[0031] 8. The internal circulation fan will not rotate at full speed to increase the life of the internal circulation fan;

[0032] 9. For electromagnetic components, power transformers and power inductors that need heat dissipation, they are first fixed to the heat dissipation aluminum frame by pouring thermal insulation film or ceramic substrate, and then can be attached to the second heat sink and the third heat sink, or to the first heat sink;

[0033] 10. The technical solution of the utility model can not only realize mass automated production, but also achieve the heat dissipation efficiency of traditional air cooling, and also completely isolate the internal components of the power module from the outside air and dust, thereby greatly improving the service life of the switching power supply. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0035] Figure 1A schematic diagram of the cross-sectional structure of an existing switching power supply that meets IP65;

[0036] Figure 2 This is a schematic diagram of the overall structure of a high-efficiency heat dissipation switching power supply with internal and external circulation isolation air ducts according to the first embodiment of the utility model;

[0037] Figure 3 This is a schematic diagram of the overall structure of a high-efficiency heat dissipation switching power supply with internal and external circulation isolation air ducts from another perspective in the first embodiment of the utility model;

[0038] Figure 4 This is a schematic diagram of the overall structure of a high-efficiency heat dissipation switching power supply with internal and external circulation isolation air ducts according to the first embodiment of the utility model from another perspective;

[0039] Figure 5 This is a schematic diagram of the decomposed structure of a high-efficiency heat dissipation switching power supply with internal and external circulation isolation air ducts according to the first embodiment of the utility model;

[0040] Figure 6 This is a schematic cross-sectional structure diagram of a high-efficiency heat dissipation switching power supply with internal and external circulation isolation air ducts according to the first embodiment of the utility model;

[0041] Figure 7 It is another cross-sectional structural schematic diagram of a high-efficiency heat dissipation switching power supply with internal and external circulation isolation air ducts according to the first embodiment of the utility model;

[0042] Figure 8 This is a schematic cross-sectional structure diagram of a high-efficiency heat dissipation switching power supply with internal and external circulation isolation air ducts according to the second embodiment of the utility model;

[0043] Fig. 9 It is another cross-sectional structural schematic diagram of a high-efficiency heat dissipation switching power supply with internal and external circulation isolation air ducts according to the second embodiment of the utility model;

[0044] Fig.10 This is a schematic cross-sectional structure diagram of a high-efficiency heat dissipation switching power supply with internal and external circulation isolation air ducts according to the third embodiment of the utility model;

[0045] Fig.11 This is another cross-sectional structural schematic diagram of a high-efficiency heat dissipation switching power supply with internal and external circulation isolation air ducts according to the third embodiment of the utility model;

[0046] Fig.12 This is a schematic cross-sectional structure diagram of a high-efficiency heat dissipation switching power supply with internal and external circulation isolation air ducts according to a fourth embodiment of the utility model;

[0047] Fig.13 This is another cross-sectional structural schematic diagram of a high-efficiency heat dissipation switching power supply with internal and external circulation isolation air ducts according to the fourth embodiment of the utility model.

[0048] The realization of the purpose, functional features and advantages of the utility model will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0049] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0050] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back...) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0051] In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the fact that ordinary technicians in the field can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present utility model.

[0052] The utility model provides a high-efficiency heat dissipation switching power supply with internal and external circulation isolation air ducts.

[0053] Embodiment 1

[0054] like Figures 2 to 7As shown, in this embodiment, the high-efficiency heat dissipation switching power supply with internal and external circulation isolation air ducts includes an outer shell 101, an inner shell 102, a PCBA power board 103, a magnetic device 104, a heat dissipation aluminum frame 105, a power MOS tube 106, an internal circulation fan 107, an external circulation fan 108 and a waterproof joint 109, the inner shell 102 is arranged in the outer shell 101, the outer shell 101 includes a bottom shell 1011 and an upper cover plate 1012, the upper cover 1012 is closed and arranged at the upper end of the bottom shell 1011, the inner shell 102 includes a first radiator 1021, a second radiator 1022, a third radiator 1023 and a lower sealing plate 1024, the second radiator 1022 and the third radiator 1023 are respectively arranged at the first heat dissipation The lower end wall of the first heat sink 1021 is surrounded by the inner side walls of the second heat sink 1022 and the third heat sink 1023 to form a receiving groove 1025. The lower sealing plate 1024 is closed and arranged at the lower end of the receiving groove 1025 to form an inner circulation sealed cavity. One PCBA power board 103 is provided. The PCBA power board 103 is arranged in the receiving groove 1025. The heat dissipation aluminum frame 105 is arranged at the upper end of the PCBA power board 103. The upper end wall of the heat dissipation aluminum frame 105 is fixedly connected to the lower end wall of the first heat sink 1021 through a thermally conductive insulating film or a ceramic substrate. The magnetic device 104 is arranged in the heat dissipation aluminum frame 105. The magnetic device 104 is connected to the heat dissipation aluminum frame through a thermally conductive insulating film or a ceramic substrate. 105 is fixedly connected, the outer side walls of the power MOS tube 106 are fixedly connected to the inner side walls of the second radiator 1022 and the third radiator 1023 through a thermally conductive insulating film or a ceramic substrate. After the overall assembly, the lower end pins of the magnetic device 104 and the power MOS tube 106 are welded and fixedly connected to the upper end wall of the PCBA power board 103 by means of a plug-in. Both ends of the PCBA power board 103 are respectively connected to the end walls of the lower sealing plate 1024 at intervals, and the PCBA power board 103 is respectively connected to the lower end wall of the first radiator 1021 and the upper end wall of the lower sealing plate 1024 at intervals. The internal circulation fan 107 is arranged in the middle of one end of the PCBA power board 1024. The PCBA power board 103 is respectively connected to the first radiator 1021. The gap between the lower end wall and the upper end wall of the lower sealing plate 1024 forms an internal circulation air duct 110 for upper and lower circulation. The upper end wall of the first radiator 1021 and the outer side walls of the second radiator 1022 and the third radiator 1023 are respectively provided with a plurality of heat sinks 111 at intervals. One end wall of the outer shell 101 is recessed with at least three air inlets 112, and the air inlets 112 are respectively arranged on the outside of the heat sinks 111. The external circulation fans 108 are respectively arranged on the inner side of the air inlets 112. The other end wall of the outer shell 101 is provided with a plurality of air outlets 113. The air inlet 112, the gap between two adjacent heat sinks 111 and the air outlets 113 form an external circulation air duct 114. The waterproof joints 109 are respectively arranged on the end walls of the lower sealing plate 1024.

[0055] Specifically, the outer shell 101 and the inner shell 102 are both made of aluminum alloy, and the protection levels of the outer shell 101 and the inner shell 102 are both IP65.

[0056] Specifically, the external circulation fan is a waterproof fan and adopts the following special design. The external circulation fan is detachably fixedly connected to the outer shell by two diagonal screws. Installation and disassembly only require turning the two diagonal screws to facilitate replacement of the fan. A fan protection cover is provided on the outside of the external circulation fan. The fan protection cover uses a separate component to simultaneously protect and fix the fan. Near the internal circulation fan, a cable-to-cable waterproof connector is used. The connector can be easily disconnected by removing the upper cover.

[0057] Specifically, the joints between the first radiator, the second radiator and the third radiator, as well as the joints between the first radiator, the second radiator and the third radiator and the lower sealing plate are sealed using waterproof rubber strips, so that the inner circulation air duct and the outer circulation air duct can be completely isolated to achieve IP65 requirements.

[0058] Specifically, in this embodiment, the rotation speed of the internal circulation fan is lower than 75% of its maximum rotation speed. Since the rotation speed of the internal circulation fan does not reach its maximum rotation speed (not full rotation), the service life of the internal circulation fan can be increased.

[0059] Specifically, in this embodiment, a plurality of heat sinks are protruded and spaced apart from each other on both side walls of the heat sink aluminum frame, which can increase the heat sink area and thus enhance the heat sink effect of the heat sink aluminum frame.

[0060] Embodiment 2

[0061] The difference between this embodiment and the first embodiment is that:

[0062] like Figure 8 and Fig. 9 As shown, in this embodiment, the upper end wall of the first radiator 1021 is arranged in a planar structure, the outer side walls of the second radiator 1022 and the third radiator 1023 are respectively provided with a plurality of heat sinks 111 at intervals, two external circulation fans 108 are provided, and the air inlets 112 are respectively arranged on both sides of an end wall of the outer shell 101, and the external circulation fans 108 are respectively arranged on the inner side of the air inlets 112.

[0063] Embodiment 3

[0064] The difference between this embodiment and the second embodiment is that:

[0065] like Fig.10 and Fig.11As shown, in this embodiment, two PCBA power boards 103 are provided, and the PCBA power boards 103 are arranged side by side in the accommodating groove 1025. The two PCBA power boards 103 are fixedly connected by copper bars, wires or PCBA board welding. A partition 115 is protruded between the two PCBA power boards 103. The upper end wall of the partition 115 abuts against the lower end wall of the first radiator 1021. Both ends of the partition 115 are spaced and connected to the end wall of the lower sealing plate 1024. The internal circulation fan 107 is located on one side of the partition 115. The partition 115 and the gaps between the inner side walls of the second radiator 1022 and the third radiator 1023 respectively form an internal circulation air duct 110 for left-right circulation.

[0066] Embodiment 4

[0067] The difference between this embodiment and the third embodiment is that:

[0068] like Fig.12 and Fig.13 As shown, in the present embodiment, one external circulation fan 108 is provided, the outer wall of the second radiator 1022 is arranged in a planar structure, and the outer wall of the third radiator 1023 is provided with a plurality of heat sinks 111 at intervals, or the outer wall of the second radiator 1022 is provided with a plurality of heat sinks 111 at intervals, and the outer wall of the third radiator 1023 is arranged in a planar structure, the air inlet 112 is respectively arranged on one side of one end wall of the outer shell 101, the air inlet 112 is located on the inner side of the heat sink 111, and the external circulation fan 108 is respectively arranged on the inner side of the air inlet 112.

[0069] Specifically, the utility model, since the inner circulation air duct and the outer circulation air duct are independently isolated from each other, when the switching power supply is working, the heat of the power device can be quickly and evenly and efficiently dissipated to the external environment. In addition, after the first heat sink, the second heat sink and the third heat sink are assembled with the power device, they are welded in the PCBA power board in the form of an integral plug-in, which can eliminate the assembly stress of the power device pins, thereby improving the reliability and service life of the switching power supply module.

[0070] The technical solution of the utility model has the following advantages:

[0071] (1) The power switch tube is soldered by standard wave soldering, which is highly efficient, has no quality risk, and has no power switch tube pin assembly stress; this can greatly improve the efficiency of mass production;

[0072] (2) The radiator can be made of aluminum profiles, which is lower in cost and has higher heat dissipation efficiency than traditional cast aluminum. Because of the fan, the heat dissipation efficiency is comparable to that of air cooling. This can make the switching power supply module have the advantages of light weight and low cost.

[0073] (3) The internal circulation air duct makes the temperature rise of components more uniform, improves the heat dissipation efficiency, avoids excessive temperature rise, and prolongs the service life of the switching power supply module;

[0074] (4) The PCBA power board does not require manual soldering (it can be automatically soldered using standard reflow soldering and wave soldering processes), and the entire machine can meet IP65 requirements.

[0075] The above description is only a preferred embodiment of the utility model, and does not limit the patent scope of the utility model. All equivalent structural changes made by using the contents of the utility model specification and drawings under the utility model concept, or directly / indirectly used in other related technical fields are included in the patent protection scope of the utility model.

Claims

1. A high-efficiency heat dissipation switching power supply with internal and external circulation isolation air ducts, characterized in that: The invention comprises an outer shell, an inner shell, a PCBA power board, a magnetic device, a heat dissipation aluminum frame, a power MOS tube, an inner circulation fan, an outer circulation fan and a waterproof joint, wherein the inner shell is arranged in the outer shell, the outer shell comprises a bottom shell and an upper cover plate, the upper cover is closed and arranged at the upper end of the bottom shell, the inner shell comprises a first radiator, a second radiator, a third radiator and a lower sealing plate, the second radiator and the third radiator are respectively arranged on both sides of the lower end wall of the first radiator, the lower end wall of the first radiator and the inner side walls of the second radiator and the third radiator The lower sealing plate is sealed and arranged at the lower end of the accommodating groove to form an inner circulation sealed cavity. The PCBA power board is provided with one piece, and the PCBA power board is arranged in the accommodating groove. The heat dissipation aluminum frame is arranged at the upper end of the PCBA power board. The upper end wall of the heat dissipation aluminum frame is fixedly connected to the lower end wall of the first radiator through a thermally conductive insulating film or a ceramic substrate. The magnetic device is arranged in the heat dissipation aluminum frame, and the magnetic device is fixedly connected to the heat dissipation aluminum frame to form an integrated structure. The outer side of the power MOS tube The inner walls are respectively fixedly connected to the inner side walls of the second radiator and the third radiator, and the lower end pins of the magnetic device and the power MOS tube are fixedly connected to the upper end wall of the PCBA power board by welding, both ends of the PCBA power board are respectively spaced apart from the end walls of the lower sealing plate, and the PCBA power board is respectively spaced apart from the lower end wall of the first radiator and the upper end wall of the lower sealing plate, the internal circulation fan is arranged in the middle of one end of the PCBA power board, and the PCBA power board is respectively spaced apart from the lower end wall of the first radiator and the upper end wall of the lower sealing plate The gap between them forms an internal circulation air duct, the upper end wall of the first radiator and the outer side walls of the second radiator and the third radiator are respectively provided with a plurality of heat sinks at intervals, one end wall of the outer shell is recessed with at least 3 air inlets, the air inlets are respectively arranged on the outsides of the heat sinks, the external circulation fans are respectively detachably arranged on the inner sides of the air inlets, the other end wall of the outer shell is provided with a plurality of air outlets, the air inlets, the gaps between two adjacent heat sinks and the air outlets form an external circulation air duct, and the waterproof joints are respectively arranged on the end walls of the lower sealing plate.

2. The high-efficiency heat dissipation switching power supply with internal and external circulation isolation air ducts according to claim 1 is characterized in that: The upper end wall of the first radiator is arranged in a planar structure, the outer side walls of the second radiator and the third radiator are respectively provided with a plurality of heat sinks at intervals, two external circulation fans are provided, the air inlets are respectively arranged on both sides of an end wall of the outer shell, and the external circulation fans are respectively arranged on the inner side of the air inlets.

3. The high-efficiency heat dissipation switching power supply with internal and external circulation isolation air ducts according to claim 2 is characterized in that: Two PCBA power boards are provided, and the PCBA power boards are arranged side by side in the accommodating groove, and the two PCBA power boards are fixedly connected to each other. A partition is protruded between the two PCBA power boards, and the upper end wall of the partition abuts against the lower end wall of the first radiator. Both ends of the partition are spaced and connected with the end wall of the lower sealing plate. The internal circulation fan is located on one side of the partition, and the partition forms an internal circulation air duct with the gap between the inner side walls of the second radiator and the third radiator.

4. The high-efficiency heat dissipation switching power supply with internal and external circulation isolation air ducts according to claim 3, characterized in that: There is one external circulation fan, the outer wall of the second radiator is arranged in a planar structure and the outer wall of the third radiator is provided with a plurality of heat sinks at intervals, or the outer wall of the second radiator is provided with a plurality of heat sinks at intervals and the outer wall of the third radiator is arranged in a planar structure, the air inlets are respectively arranged on one side of one end wall of the outer shell, and the air inlets are arranged on the inner side of the heat sinks.

5. The high-efficiency heat dissipation switching power supply with internal and external circulation isolation air ducts according to claim 1, characterized in that: The outer shell and the inner shell are both made of aluminum alloy.

6. The high-efficiency heat dissipation switching power supply with internal and external circulation isolation air ducts according to claim 1, characterized in that: The protection levels of the outer shell and the inner shell are both IP65.

7. The high-efficiency heat dissipation switching power supply with internal and external circulation isolation air ducts according to claim 1, characterized in that: The external circulation fan is a waterproof fan.

8. The high-efficiency heat dissipation switching power supply with internal and external circulation isolation air ducts according to claim 1, characterized in that: The rotation speed of the internal circulation fan is lower than 75% of its maximum rotation speed.

9. The high-efficiency heat dissipation switching power supply with internal and external circulation isolation air ducts according to claim 1, characterized in that: A plurality of heat sinks are protruded and spaced apart on both side walls of the heat sink aluminum frame.

10. The high-efficiency heat dissipation switching power supply with internal and external circulation isolation air ducts according to claim 1, characterized in that: A waterproof rubber strip is provided at the joints among the first radiator, the second radiator and the third radiator, and at the joints between the first radiator, the second radiator and the third radiator and the lower sealing plate.

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