Air conditioner outdoor unit

Abstract

A toroidal coil cooling structure (100) comprises a toroidal coil (10), a printed wiring board (9), a partition plate (8), thermal paste (17), a pillar (51), and a pressing plate (50). An overhang section (18b) of a winding (13) is connected to the printed wiring board (9) so as to be able to move the toroidal coil (10) in a direction in which the toroidal coil (10) overlaps the thermal paste (17). The pressing plate (50) is configured to press the toroidal coil (10) against the thermal paste (17).

Description

Cooling structure of toroidal coil and outdoor unit of air conditioner

[0001] The present disclosure relates to a cooling structure for a toroidal coil and an outdoor unit for an air conditioner.

[0002] Conventionally, cooling structures for toroidal coils have been known. For example, Japanese Patent Laid-Open Publication No. 2020-188131 (Patent Document 1) describes a cooling structure for a toroidal coil. In this publication, a portion of the toroidal coil located on the opening side of the coil cover is thermally connected to the housing.

[0003] Japanese Patent Application Laid-Open No. 2020-188131

[0004] When winding a toroidal coil, the height of the winding can vary depending on the winding method, the start and end of the winding, and other factors. In particular, in power electronics equipment with high currents, such as outdoor units for air conditioners, thick metal wire is used to prevent the temperature rise of the toroidal coil winding. When the metal wire is thick, the bending pressure required for plastic forming increases, leading to greater variations. Furthermore, in toroidal coils, the ends of the winding wire are inserted into through-holes in the printed circuit board and fixed in place with solder, which can cause variations in the mounting height.

[0005] In the above publication, a gap is provided between the toroidal coil and the coil cover to absorb height variations, but on the opposite side of the gap, the toroidal coil is only thermally connected to a thermally conductive sheet. Because the thermally conductive sheet is thermally connected only to the outermost surface of the toroidal coil winding, the contact area is small and the thermal resistance is high.

[0006] Furthermore, the heat dissipation sheet must be thick to accommodate variations in the winding height and mounting height of the toroidal coil. Typical heat dissipation sheets are made of flexible resin and thermally conductive filler, but there is a limit to how much they can be compressed, generally said to be around 30%. For example, a 1mm thick heat dissipation sheet can only be compressed to about 0.3mm, so a 1mm variation requires a heat dissipation sheet thickness of about 3mm. Since thermal resistance is inversely proportional to the contact area and thermal conductivity and proportional to the thickness, the thicker the sheet, the greater the thermal resistance.

[0007] The present disclosure has been made in consideration of the above-mentioned problems, and its purpose is to provide a cooling structure for a toroidal coil that can absorb winding variations and fixing variations of the toroidal coil, achieve thermal connections with an expanded contact area, and dissipate heat with low thermal resistance, and an outdoor unit of an air conditioner that is equipped with the same.

[0008] The cooling structure for a toroidal coil disclosed herein includes a toroidal coil, a printed wiring board, a metal housing, thermal grease, pillars, and a presser plate. The toroidal coil includes a core and a winding wound around the core. The printed wiring board has a toroidal coil mounted thereon and includes a front surface and a back surface. The metal housing is disposed on the back surface of the printed wiring board opposite the front surface. The thermal grease is disposed between the toroidal coil and the metal housing. The pillars are supported by the metal housing. The presser plate is connected to the pillars and sandwiches the toroidal coil between the metal housing and the pillars. The winding includes a protruding portion that protrudes from the core and extends along the surface of the printed wiring board. The protruding portion of the winding is connected to the printed wiring board so that the toroidal coil can move in a direction where the toroidal coil overlaps the thermal grease. The presser plate is configured to press the toroidal coil against the thermal grease.

[0009] The toroidal coil cooling structure of the present disclosure absorbs winding variations and fixing variations of the toroidal coil, realizes thermal connections with an increased contact area, and enables heat dissipation with low thermal resistance.

[0010] 1 is a schematic diagram showing the front side of an outdoor unit of an air conditioning apparatus according to embodiment 1. FIG. 2 is a schematic diagram showing the plan side of the outdoor unit of an air conditioning apparatus according to embodiment 1. FIG. 3A is a schematic top view and FIG. 3B is a schematic side view of a toroidal coil according to embodiment 1. FIG. 4 is a schematic cross-sectional view showing the cooling structure of a toroidal coil according to embodiment 1. FIG. 5 is a schematic cross-sectional view showing the cooling structure of a toroidal coil according to embodiment 2. FIG. 6 is a schematic cross-sectional view showing the cooling structure of a toroidal coil according to embodiment 3. FIG. 7 is a schematic cross-sectional view showing the cooling structure of a toroidal coil according to embodiment 4. FIG. 8 is a schematic cross-sectional view showing the cooling structure of a toroidal coil according to embodiment 5. FIG. 9A is a schematic top view and FIG. 9B is a schematic side view of a toroidal coil according to embodiment 5. FIG. 9B is a schematic cross-sectional view showing the cooling structure of a toroidal coil according to embodiment 6. FIG. 12A is a schematic top view and FIG. 12B is a schematic side view of a toroidal coil according to embodiment 7. 13A is a schematic top view and FIG. 13B is a schematic side view of a toroidal coil according to embodiment 7. FIG. 13B is a schematic cross-sectional view showing a cooling structure of a toroidal coil according to embodiment 8. FIG. 13C is a schematic cross-sectional view showing a leaf spring before fixing the toroidal coil according to embodiment 8. FIG. 13D is a schematic perspective view showing a leaf spring of the cooling structure of a toroidal coil according to embodiment 8.

[0011] Hereinafter, embodiments will be described with reference to the drawings. In the drawings, the same or corresponding parts are designated by the same reference numerals and description thereof will not be repeated.

[0012] Embodiment 1. First, the configuration of an outdoor unit 1 of an air conditioning apparatus according to Embodiment 1 will be described. Fig. 1 is a schematic diagram showing the outdoor unit 1 of an air conditioning apparatus according to Embodiment 1 from the front side. Fig. 2 is a schematic diagram showing the outdoor unit 1 of an air conditioning apparatus according to Embodiment 1 from the top side.

[0013] 1 and 2 , an outdoor unit 1 of an air conditioner according to this embodiment incorporates a compressor 2, a heat exchanger 3, a circuit board mounting plate 4, an outdoor unit fan 5, and the like. The outdoor unit 1 of the air conditioner includes a cooling structure 100 for a toroidal coil 10. The outdoor unit 1 includes a blower chamber 7 in which the outdoor unit fan 5 for blowing air is disposed, a machinery chamber 6 in which a printed wiring board 9 is disposed, and a partition plate 8 separating the blower chamber 7 from the machinery chamber 6. The outdoor unit 1 is divided into the machinery chamber 6 and the blower chamber 7 by the partition plate 8. The compressor 2 and the circuit board mounting plate 4 are disposed in the machinery chamber 6. The heat exchanger 3 and the outdoor unit fan 5 are disposed in the blower chamber 7. The partition plate 8 is configured to prevent water droplets from entering the machinery chamber 6 from the blower chamber 7. The partition plate 8 is configured from a thermally conductive metal plate or the like.

[0014] The compressor 2 is disposed at the bottom of the machine chamber 6. The circuit board mounting plate 4 is disposed at the top of the machine chamber 6. The heat exchanger 3 is disposed along the back and side of the outdoor unit 1. The outdoor unit fan 5 is disposed closer to the front of the outdoor unit 1 than the heat exchanger 3. When the outdoor unit fan 5 rotates, heat exchanger airflow 40 flows through the heat exchanger 3 and is discharged from the front of the outdoor unit 1. The heat exchanger airflow 40 flows along the surface of the partition plate 8 facing the blower chamber 7. Therefore, the partition plate 8 is cooled by heat transfer from the heat exchanger airflow 40.

[0015] 3A is a schematic top view of the toroidal coil 10 according to embodiment 1, and FIG. 3B is a schematic side view thereof. FIG. 4 is a schematic cross-sectional view showing a cooling structure 100 of the toroidal coil 10 according to embodiment 1.

[0016] The configuration of the cooling structure 100 for the toroidal coil 10 according to the first embodiment will be described with reference to FIGS. 3 and 4. FIG.

[0017] The cooling structure 100 for the toroidal coil 10 according to the first embodiment includes the toroidal coil 10, a printed wiring board 9, a partition plate 8, thermal grease 17, columns 51, and a pressing plate 50. The partition plate 8 is a metal housing C.

[0018] The toroidal coil 10 includes a core 11, a core case 12, windings 13, and an insulating partition plate 14. The core 11 is made of a magnetic material. The core 11 has a donut shape. The core case 12 houses the core 11. The core case 12 is made of an insulating material such as resin. The core case 12 is shaped to cover the core 11. The windings 13 are made of enameled wire, which is metal wiring such as copper covered with enamel. The windings 13 are wound around the core 11. The windings 13 are wound around the core case 12 to achieve the required inductance value. The insulating partition plate 14, like the core case 12, is made of an insulating material such as resin. The insulating partition plate 14 is positioned to separate the windings 13 at different potentials to prevent short circuits between the windings at different potentials. The insulating partition plate 14 holds the core 11. The core case 12 and the insulating partition plate 14 are either integrated or assembled. The winding 13 of the toroidal coil 10 includes a protruding portion 18b. The protruding portion 18b protrudes from the core 11 and extends along the surface FS of the printed wiring board 9. The protruding portion 18b extends horizontally to the outside of the toroidal coil 10. A wiring end 18a of the winding 13 of the toroidal coil 10 is joined to a crimp terminal 19. The crimp terminal 19 has a configuration that can be fastened with a screw, such as a round crimp terminal or a Y-type crimp terminal.

[0019] The toroidal coil 10 is mounted on a printed wiring board 9. The printed wiring board 9 includes a front surface FS and a back surface RS. The printed wiring board 9 has an opening 9a larger than the component dimensions of the toroidal coil 10 so that the toroidal coil 10 can pass through. Because the toroidal coil 10 is placed within the opening 9a, the toroidal coil 10 does not interfere with the printed wiring board 9. The wiring end 18a of the toroidal coil 10 is joined to a crimp terminal 19. The wiring end 18a of the toroidal coil 10 is electrically connected to a terminal block 21 mounted on the printed wiring board 9 via the crimp terminal 19 by a screw 22. The protruding portion 18b of the winding 13 is connected to the printed wiring board 9 so that the toroidal coil 10 can move in the direction where it overlaps the thermal grease 17. The protruding portion 18b is made of elastic metal, allowing the toroidal coil 10 to move up and down and absorb variations in height.

[0020] Although an example has been described in which the printed wiring board 9 and the toroidal coil 10 are connected using crimp terminals 19, terminal blocks 21, and screws 22, the same effect can be obtained if the wiring end 18a of the toroidal coil 10 is directly joined to the printed wiring board 9 by soldering or the like.

[0021] The board mounting plate 4 is connected and fixed to the outer plate of the housing of the outdoor unit 1 via a support member. A printed wiring board 9 carrying electronic components such as power semiconductors is placed on the board mounting plate 4, and the printed wiring board 9 is fixed with screws, resin spacers, etc. The board mounting plate 4 has an opening 4a on the partition plate 8 side so that the power semiconductors and toroidal coil 10 can be thermally connected to the partition plate 8. The opening 4a is larger than the dimensions of the power semiconductors and toroidal coil 10 so that they can pass through.

[0022] The toroidal coil 10 passes through the opening 9a in the printed wiring board 9 and the opening 4a in the PCB mounting plate 4 and is thermally connected to the partition plate 8. The partition plate 8 is disposed on the opposite side of the back surface RS of the printed wiring board 9 from the front surface FS. Thermal grease 17 is disposed between the toroidal coil 10 and the partition plate 8. The thermal grease 17 only needs to have a viscosity sufficient to hold the toroidal coil 10. Both hardening and non-hardening thermal greases can be used as the thermal grease 17. In this embodiment, hardening thermal grease is used as an example of the thermal grease 17. The thermal grease 17 can be one that hardens after a certain period of time has passed after application, or one that hardens when exposed to ultraviolet light, for example. The thermal grease 17 is applied to the gap between the toroidal coil 10 and the partition plate 8 before hardening. Because the thermal grease 17 is in a gel state before hardening, it can be applied circumferentially to the windings 13 and core case 12 regardless of variations in the height of the windings 13 of the toroidal coil 10. This allows for a larger contact heat dissipation area. The toroidal coil 10 and partition plate 8 are fixed together when the thermal grease 17 hardens. Heat from the toroidal coil 10 is transferred to the partition plate 8 via the thermal grease 17. The heat transferred to the partition plate 8 is dissipated to the blower chamber 7 by the air blown by the outdoor unit fan 5.

[0023] The toroidal coil 10 is sandwiched between the pressure plate 50 and the partition plate 8. The pressure plate 50 is configured to press the toroidal coil 10 against the thermal grease 17. The pressure plate 50, made of an elastic material, presses down the toroidal coil 10 to press the toroidal coil 10 against the partition plate 8. The pressure plate 50 may be square, circular, or other shapes. The pressure plate 50 is sized to cover the toroidal coil 10.

[0024] The pillars 51 are supported by the partition plate 8. The retainer plate 50 has screw holes at positions corresponding to the pillars 51. The retainer plate 50 is connected to the pillars 51. Specifically, the retainer plate 50 is fixed to the pillars 51 with cap screws 52. Although two pillars 51 are shown in FIG. 4 , if the retainer plate 50 is rectangular, the pillars 51 may be four, arranged at the four corners of the retainer plate 50, two diagonally, or three, arranged to form a triangle. The pillars 51 are fixed to the partition plate 8 by screws, welding, adhesive, or the like. The height of the pillars 51 is designed to be lower than the combined height of the toroidal coil 10 and the thermal grease 17. Therefore, when the retainer plate 50 is fixed to the pillars 51, the elastic retainer plate 50 receives a force that deforms it into an upwardly convex shape, pressing the toroidal coil 10 toward the partition plate 8. When the toroidal coil 10 is pressed, the thermal grease 17 between the toroidal coil 10 and the partition plate 8 is compressed. This reduces the thickness of the thermal grease 17, increases the contact pressure, and makes it possible to maintain low thermal resistance.

[0025] The displacement δ of the pressure plate 50 and the Young's modulus E of the pressure plate 50 are selected so that the pressing force is smaller than the allowable compressive force FC of the toroidal coil 10 and larger than the compressive force FA required to keep the thermal resistance low.

[0026] Next, the effects of this embodiment will be described. According to the cooling structure 100 for the toroidal coil 10 of embodiment 1, the protruding portions 18b of the winding 13 are connected to the printed wiring board 9 so that the toroidal coil 10 can move in a direction in which the toroidal coil 10 overlaps the thermal grease 17. Therefore, the elasticity of the protruding portions 18b of the winding 13 can absorb winding variations and fixing variations of the toroidal coil 10. The thermal grease 17 is disposed between the toroidal coil 10 and the partition plate 8. The thermal grease 17 is applied between the toroidal coil 10 and the partition plate 8 in an unhardened state, thereby increasing the contact area with the toroidal coil 10. The presser plate 50 is configured to press the toroidal coil 10 against the thermal grease 17. Therefore, the thermal grease 17 disposed between the toroidal coil 10 and the partition plate 8 is compressed, thereby reducing the thickness of the thermal grease 17. Therefore, the heat dissipation grease 17 allows heat to be dissipated with low thermal resistance.

[0027] Furthermore, the pressure generated by the elasticity of the presser plate 50 presses the toroidal coil 10 against the thermal grease 17. Therefore, even if the thermal grease 17 between the toroidal coil 10 and the partition plate 8 is momentarily peeled off due to vibration or the like, the contact pressure is restored, allowing the toroidal coil 10 to return to a low thermal resistance state.

[0028] By filling the gap between the winding 13 of the toroidal coil 10 and the partition plate 8 with a general thermal grease 17 that has both high thermal conductivity and insulating properties, it is possible to achieve both insulation and heat dissipation. Because the thermal grease 17 is in a gel state before hardening, it not only absorbs variations in the height of the winding 13 but also makes contact with the winding 13 circumferentially. This increases the contact area and improves thermal conductivity to the partition plate 8. As the thermal grease 17 hardens, it can fix the partition plate 8 and the toroidal coil 10 together.

[0029] The structure that can dissipate heat from the windings 13 of the toroidal coil 10 and the improved thermal conduction efficiency of the thermal grease 17 make it difficult for the temperature of the windings 13 to rise. This allows current to flow through a coil of conventional dimensions. Alternatively, the coil windings can be replaced with thinner ones, allowing for a smaller coil size. Furthermore, the enameled wire of the windings 13 can be replaced with a cheaper, more user-friendly one with a lower heat resistance class.

[0030] The outdoor unit 1 of the air conditioner according to the first embodiment includes the cooling structure 100 for the toroidal coil 10. Heat from the winding 13 of the toroidal coil 10 is conducted to the partition plate 8 via the thermal grease 17. The heat is then transferred from the partition plate 8 to the heat exchanger airflow 40. In this way, the heat can be discharged to the outside of the outdoor unit 1 via the heat exchanger airflow 40.

[0031] Second Embodiment Fig. 5 is a schematic cross-sectional view showing a cooling structure 100 for a toroidal coil 10 according to a second embodiment.

[0032] Referring to FIG. 5, the cooling structure 100 for the toroidal coil 10 according to the second embodiment includes a heat sink 23 and a thermally conductive sheet 24 (first thermally conductive sheet 24a).

[0033] Thermal grease 17, a heat sink 23, and a first thermally conductive sheet 24a are arranged between the toroidal coil 10 and the partition plate 8. The heat sink 23 is sandwiched between the thermal grease 17 and the first thermally conductive sheet 24a. The first thermally conductive sheet 24a is sandwiched between the heat sink 23 and the partition plate 8. The heat sink 23 is a metal plate with high thermal conductivity, such as aluminum or copper. The thermally conductive sheet 24 is composed of a flexible resin and a thermally conductive filler. The thermal grease 17 is applied to the gap between the toroidal coil 10 and the heat sink 23 before hardening. The toroidal coil 10 and the heat sink 23 are fixed together when the thermal grease 17 hardens. Heat from the toroidal coil 10 is transferred to the heat sink 23 via the thermal grease 17. The heat transferred to the heat sink 23, which is a metal plate with high thermal conductivity, is diffused in the area direction (in-plane direction) of the heat sink 23. The heat diffused uniformly in the area direction of the heat sink 23 is transferred perpendicularly to the partition plate 8 by the heat conduction sheet 24.

[0034] The height of the pillars 51 is designed to be lower than the combined height of the toroidal coil 10, thermal grease 17, heat sink 23, and thermally conductive sheet 24. Therefore, when the retainer plate 50 is fixed to the pillars 51, the toroidal coil 10 is pressed against the partition plate 8 by the reaction force of the elastic retainer plate 50. As the toroidal coil 10 is pressed, the thermally conductive sheet 24 and the thermal grease 17 between the toroidal coil 10 and the heat sink 23 are compressed. This reduces the thickness of the thermally conductive sheet 24 and thermal grease 17, increasing the contact pressure and making it possible to maintain low thermal resistance.

[0035] Next, the effects of this embodiment will be described. According to the cooling structure 100 for the toroidal coil 10 of embodiment 2, the heat sink 23 is sandwiched between the thermal grease 17 and the first thermally conductive sheet 24a. The first thermally conductive sheet 24a is sandwiched between the heat sink 23 and the partition plate 8. This allows heat from the toroidal coil 10 to be transferred to the partition plate 8 via the thermal grease 17, the heat sink 23, and the first thermally conductive sheet 24a. This improves heat transfer.

[0036] Third Embodiment Fig. 6 is a schematic cross-sectional view showing a cooling structure 100 for a toroidal coil 10 according to a third embodiment.

[0037] Referring to FIG. 6 , the cooling structure 100 for the toroidal coil 10 according to the third embodiment includes a second thermally conductive sheet 24b. The second thermally conductive sheet 24b is sandwiched between a pressure plate 50 and the toroidal coil 10. The repulsive force of the second thermally conductive sheet 24b presses the toroidal coil 10 against the thermal grease 17. The second thermally conductive sheet 24b is also placed on the toroidal coil 10 to press the toroidal coil 10 against the partition plate 8. A pressure plate 50 made of a metal such as aluminum or copper presses the second thermally conductive sheet 24b from above. The height of the pillar 51 is designed to be lower than the combined height of the second thermally conductive sheet 24b, the toroidal coil 10, the thermal grease 17, the heat sink 23, and the first thermally conductive sheet 24a. Therefore, when the presser plate 50 is fixed to the pillar 51, the reaction force of the first thermally conductive sheet 24a and the second thermally conductive sheet 24b expanding from their contracted state presses the toroidal coil 10 against the partition plate 8. As the toroidal coil 10 is pressed, the first thermally conductive sheet 24a, the second thermally conductive sheet 24b, and the thermal grease 17 between the toroidal coil 10 and the heat sink 23 are compressed. This reduces the thickness of the first thermally conductive sheet 24a, the second thermally conductive sheet 24b, and the thermal grease 17, increasing the contact pressure and making it possible to maintain low thermal resistance.

[0038] Furthermore, in this structure, heat is dissipated not only from the partition plate 8 side but also from the presser plate 50 side through the second thermally conductive sheet 24b. To further increase heat dissipation from the presser plate 50 side, heat dissipation fins (not shown) may be added to the presser plate 50. In this embodiment, heat can be dissipated from both the presser plate 50 side and the partition plate 8 side.

[0039] Next, the effects of this embodiment will be described. According to the cooling structure 100 for the toroidal coil 10 of embodiment 3, the second thermally conductive sheet 24b is sandwiched between the presser plate 50 and the toroidal coil 10. The repulsive force of the second thermally conductive sheet 24b presses the toroidal coil 10 against the thermal grease 17. Therefore, the repulsive force of the second thermally conductive sheet 24b compresses the thermal grease 17, thereby making it possible to reduce the thickness of the thermal grease 17. Therefore, the thermal grease 17 can dissipate heat with low thermal resistance.

[0040] Furthermore, heat generated in the winding 13 of the toroidal coil 10 can be dissipated not only to the partition plate 8 side but also to the presser plate 50 side through the second thermally conductive sheet 24b.

[0041] Fourth Embodiment Fig. 7 is a schematic cross-sectional view showing a cooling structure 100 for a toroidal coil 10 according to a fourth embodiment.

[0042] Referring to FIG. 7 , the cooling structure 100 for the toroidal coil 10 according to the fourth embodiment includes a spring screw 53. The spring screw 53 includes a spring 53a. The spring screw 53 also includes a screw body 53b that holds the spring 53a in an expandable and contractible manner. A presser plate 50 is placed on the toroidal coil 10 to press the toroidal coil 10 against the partition plate 8. The presser plate 50 may be made of resin or a metal such as aluminum or copper. The presser plate 50 has a hole for fixing the spring screw. A screw body 53b is fixed in the hole for fixing the spring screw. With the screw body 53b fixed in the hole for fixing the spring screw, the spring 53a is configured to bias the presser plate 50.

[0043] The pressure plate 50 is held to the pillar 51 by a spring-loaded screw 53. The repulsive force of the spring 53a of the spring-loaded screw 53 presses the pressure plate 50 against the toroidal coil 10. The repulsive force of the spring 53a of the spring-loaded screw 53 presses the pressure plate 50 toward the partition plate 8. As a result, the toroidal coil 10 is pressed down toward the partition plate 8.

[0044] The height of the pillar 51 is designed to be lower than the combined height of the toroidal coil 10, thermal grease 17, heat sink 23, and thermally conductive sheet 24, so that the spring 53a of the spring-loaded screw 53 is compressed to apply an appropriate compressive force to the toroid. The repulsive force of the spring 53a presses down the presser plate 50, thereby pressing the toroidal coil 10 against the partition plate 8.

[0045] Next, the effects of this embodiment will be described. According to the cooling structure 100 for the toroidal coil 10 of embodiment 4, the pressing plate 50 is pressed against the toroidal coil 10 by the repulsive force of the spring 53a of the spring-loaded screw 53. This compresses the thermal grease 17 disposed between the toroidal coil 10 and the partition plate 8, thereby reducing the thickness of the thermal grease 17. This allows the thermal grease 17 to dissipate heat with low thermal resistance.

[0046] Furthermore, even if the heat dissipation grease 17 between the toroidal coil 10 and the partition plate 8 is momentarily peeled off due to vibration or the like, the repulsive force of the spring 53a of the spring-loaded screw 53 allows the contact pressure to be restored, thereby returning the device to a state of low thermal resistance.

[0047] Fifth Embodiment Fig. 8 is a schematic cross-sectional view showing a cooling structure 100 of a toroidal coil 10 according to a fifth embodiment. Fig. 9 is a schematic top view of the toroidal coil 10 according to the fifth embodiment (Fig. 9A) and a schematic side view of the toroidal coil 10 according to the fifth embodiment (Fig. 9B).

[0048] 8 and 9, a through hole H is provided in the center of the toroidal coil 10 in a plan view. A pillar 51 is inserted into the through hole H. Only one pillar 51 is fixed to the center of the toroidal coil 10. In order to erect the pillar 51 at the center of the toroidal coil 10, the insulating partition plate 14 has a hole in the center that is large enough to accommodate the pillar 51.

[0049] The windings 13 of the toroidal coil 10 are covered with enamel to ensure insulation. However, if pinholes or cracks occur in the enamel coating during manufacturing or processing, insulation breakdown will occur. Therefore, if the pillars 51 are located around the periphery of the toroidal coil 10, there is a possibility that the windings 13 and the pillars 51 will short-circuit. In this embodiment, the pillars 51 are located in the center, eliminating the possibility that the pillars 51 will come into contact with the protruding portion 18b.

[0050] Next, the effects of this embodiment will be described. According to the cooling structure 100 for the toroidal coil 10 of embodiment 5, a through hole H is provided in the center of the toroidal coil 10 in a plan view. The pillars 51 are inserted into the through holes H. This prevents the pillars 51 from coming into contact with the protruding portions 18b of the windings 13.

[0051] Sixth Embodiment Fig. 10 is a schematic cross-sectional view showing a cooling structure 100 for a toroidal coil 10 according to a sixth embodiment. Fig. 11 is a schematic plan view showing the cooling structure 100 for a toroidal coil according to the sixth embodiment.

[0052] 10, in a cooling structure 100 for a toroidal coil 10 according to the sixth embodiment, there are no openings in a printed wiring board 9 and a board mounting plate 4. The toroidal coil 10 is thermally connected to a partition plate 8.

[0053] 11, the presser plate 50 is circular and has a size sufficient to cover the toroidal coil 10, but may be smaller than the toroidal coil 10. A single pillar 51 is fixed to the center of the toroidal coil 10.

[0054] 10 and 11, the toroidal coil 10 is disposed outside the outer edge of the printed wiring board 9. In other words, the toroidal coil 10 is placed at a lateral position away from the printed wiring board 9. Therefore, no opening is required in the printed wiring board 9, and the area of ​​the printed wiring board 9 can be reduced.

[0055] Next, the effects of this embodiment will be described. The toroidal coil 10 according to the sixth embodiment is disposed outside the outer edge of the printed wiring board 9. Therefore, no opening is required in the printed wiring board 9, and the area of ​​the printed wiring board 9 can be made smaller than when the printed wiring board 9 has an opening.

[0056] Seventh Embodiment Figure 12 shows a toroidal coil 10 according to a seventh embodiment, with Fig. 12A being a schematic top view and Fig. 12B being a schematic side view.

[0057] In FIG. 12 , the toroidal coil 10 is larger than the windings 13 in the direction in which the core case 12 is disposed relative to the partition plate 8. The toroidal coil 10 includes a protrusion 15 that protrudes toward the partition plate 8. The protrusion 15 is supported by the partition plate 8 so that the windings 13 are spaced apart from the partition plate 8. The protrusion 15 is provided in a location where there are no windings 13. The protrusion 15 is made of an insulating material. Specifically, the protrusion 15 is made of an insulating material such as resin, similar to the core case 12. The core case 12 also has the protrusion 15. The protrusion 15 is positioned so that when the toroidal coil 10 comes into contact with the partition plate 8, the core case 12 tilts, preventing the windings 13 from coming into contact with the partition plate 8. For example, as shown in FIG. 12 , two protrusions 15 may be provided at diagonal corners of the core case 12, and the protrusions 15 may be configured to contact the partition plate 8. As long as the winding 13 and the partition plate 8 do not come into contact with each other, the same effect can be obtained regardless of the shape and number of the protrusions 15 .

[0058] Next, a modified example of the cooling structure 100 of the toroidal coil 10 according to the seventh embodiment will be described.

[0059] 13A is a schematic top view of the toroidal coil 10 according to the seventh embodiment, and FIG. 13B is a schematic side view thereof.

[0060] In Figure 13, the toroidal coil 10 has a configuration in which the insulating partition plate 14 is larger than the winding 13 in the direction in which the partition plate 8 is disposed. The insulating partition plate 14 has a protrusion 15. The insulating partition plate 14 has a shape that prevents the winding 13 from contacting the partition plate 8 when the toroidal coil 10 comes into contact with the partition plate 8, for example by tilting the core case 12. For example, as shown in Figure 13, a cross-shaped insulating partition plate 14 may be configured to protrude beyond the winding 13, with the protrusion 15 of the insulating partition plate 14 contacting the partition plate 8. As long as the winding 13 and the partition plate 8 do not come into contact, the same effect can be obtained regardless of the shape of the protrusion 15 of the insulating partition plate 14.

[0061] Not only the protrusions 15 shown in either FIG. 12 or FIG. 13, but also both of the protrusions 15 may be provided.

[0062] The windings 13 and the partition plate 8 are connected by thermal grease 17. Since typical thermal grease 17 has both high thermal conductivity and insulating properties, the windings 13 and the partition plate 8 are thermally connected via the thermal grease 17 but are not electrically connected.

[0063] Next, the effects of this embodiment will be described. According to the cooling structure 100 for the toroidal coil 10 of embodiment 7, the protruding portion 15 of the toroidal coil 10 is supported by the partition plate 8 so that the winding 13 is spaced from the partition plate 8, and is made of an insulating material. The protruding portion 15 comes into contact with the partition plate 8, which is made of a metal plate or the like, creating a gap between the winding 13 and the partition plate 8, thereby insulating the winding 13 from the partition plate 8. This gap ensures insulation even if pinholes or cracks occur in the enamel coating of the winding 13.

[0064] The protrusions 15 of the core case 12 and the insulating partition plate 14 are made of an insulating material. In general, the dimensional variations of insulating materials such as resin can be reduced in manufacturing processes compared to the variations in the windings 13. This allows for improved positional accuracy between the partition plate 8 and the toroidal coil 10.

[0065] According to the cooling structure 100 for the toroidal coil 10 according to the seventh embodiment, the core case 12 has the protrusion 15. Therefore, the protrusion 15 can be provided on the core case 12. Furthermore, the protrusion 15 of the core case 12 can insulate the winding 13 from the partition plate 8.

[0066] According to the modified example of the cooling structure 100 for the toroidal coil 10 according to the seventh embodiment, the insulating partition plate 14 has a protrusion 15. Therefore, the protrusion 15 can be provided on the insulating partition plate 14. Furthermore, the protrusion 15 of the insulating partition plate 14 can insulate the winding 13 from the partition plate 8.

[0067] Eighth Embodiment Fig. 14 is a schematic cross-sectional view showing a cooling structure 100 for a toroidal coil 10 according to an eighth embodiment.

[0068] 14, the cooling structure 100 for the toroidal coil 10 according to the eighth embodiment includes a leaf spring 54. The leaf spring 54 is fixed to the partition plate 8. The leaf spring 54 is made of an elastic metal, and legs 54a of the leaf spring are fixed to the partition plate 8 by spot welding or the like. The shape of the leaf spring 54 shown in FIG. 14 does not need to be limited to that shown in FIG. 14 as long as the shape of the leaf spring 54 generates a force that presses the toroidal coil 10 toward the partition plate 8 when the leaf spring 54 is deformed.

[0069] 15 shows an example of the state of the leaf spring 54 before the toroidal coil 10 is fixed in place in the eighth embodiment. In this state, the leaf spring 54 is fixed to the partition plate 8 before the toroidal coil 10, thermal grease 17, and other components are fixed in place. The leaf spring 54 is not yet deformed, and no force is applied to the leaf spring 54. The leaf spring 54 is housed in the opening 4a of the board mounting plate 4 and the opening 9a of the printed wiring board 9. The leaf spring 54 is opened by bending it in the direction of the arrow in FIG. 15. After the toroidal coil 10, thermal grease 17, and other components are housed in place, the bending force is released, and the elastic force of the leaf spring 54 presses the toroidal coil 10 against the partition plate 8.

[0070] Fig. 16 is a perspective view of an example of the leaf spring 54. As shown in Figs. 14 to 16, the example of the leaf spring 54 has a straight portion extending in a straight line from the leg 54a and a curved portion protruding inward from the straight portion.

[0071] Next, the effects of this embodiment will be described. According to the cooling structure 100 for the toroidal coil 10 of embodiment 8, the elastic force of the leaf spring 54 presses the toroidal coil 10 against the partition plate 8. This compresses the thermal grease 17 disposed between the toroidal coil 10 and the partition plate 8, thereby reducing the thickness of the thermal grease 17. This allows the thermal grease 17 to dissipate heat with low thermal resistance.

[0072] Furthermore, the elastic force of the leaf spring 54 presses the toroidal coil 10 against the partition plate 8. Therefore, even if the thermal grease 17 between the toroidal coil 10 and the partition plate 8 momentarily peels off due to vibration or the like, the contact pressure is restored, allowing the toroidal coil 10 to return to a low thermal resistance state.

[0073] Furthermore, compared to the previous embodiments, the only pressing member is the leaf spring 54, making this the easiest to manufacture.

[0074] Furthermore, since the leaf spring 54 is made of metal, it also functions as a heat sink that dissipates heat from the toroidal coil 10 into the air to reduce the temperature.

[0075] The above-described embodiments and modifications can be combined as appropriate. The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present disclosure is defined by the claims, not the above description, and is intended to include all modifications within the meaning and scope of the claims.

[0076] The various aspects of the present disclosure are summarized below as appendices. (Appendix 1) A cooling structure for a toroidal coil, comprising: a toroidal coil including a core and a winding wound around the core; a printed wiring board on which the toroidal coil is mounted and including a front surface and a back surface; a metal case arranged on the back surface of the printed wiring board opposite the front surface; thermal grease arranged between the toroidal coil and the metal case; pillars supported by the metal case; and a presser plate connected to the pillars and sandwiching the toroidal coil between the metal case and the pillars, wherein the winding includes a protruding portion protruding from the core and extending along the front surface of the printed wiring board, the protruding portion of the winding is connected to the printed wiring board so as to move the toroidal coil in a direction where the toroidal coil overlaps the thermal grease, and the presser plate is configured to press the toroidal coil against the thermal grease.

[0077] (Appendix 2) The toroidal coil cooling structure according to Appendix 1, further comprising a heat sink and a first thermally conductive sheet, wherein the heat sink is sandwiched between the thermal grease and the first thermally conductive sheet, and the first thermally conductive sheet is sandwiched between the heat sink and the metal housing.

[0078] (Appendix 3) The cooling structure for a toroidal coil according to Appendix 2, further comprising a second thermally conductive sheet, the second thermally conductive sheet being sandwiched between the pressure plate and the toroidal coil, and the toroidal coil being pressed against the thermal grease by the repulsive force of the second thermally conductive sheet.

[0079] (Appendix 4) A cooling structure for a toroidal coil according to any one of Appendices 1 to 3, further comprising a spring-loaded screw, wherein the pressure plate is held to the pillar by the spring-loaded screw, the spring-loaded screw includes a spring, and the pressure plate is pressed against the toroidal coil by the repulsive force of the spring.

[0080] (Supplementary Note 5) The cooling structure for a toroidal coil according to any one of Supplementary Notes 1 to 4, wherein a through hole is provided at the center of the toroidal coil in a plan view, and the pillar is inserted into the through hole.

[0081] (Supplementary Note 6) The cooling structure for a toroidal coil according to any one of Supplementary Notes 1 to 5, wherein the toroidal coil is disposed outside an outer edge of the printed wiring board.

[0082] (Supplementary Note 7) The toroidal coil cooling structure according to any one of Supplementary Notes 1 to 6, wherein the toroidal coil includes a protruding portion that protrudes toward the metal casing, the protruding portion is supported by the metal casing so that the winding is spaced apart from the metal casing, and the protruding portion is made of an insulating material.

[0083] (Supplementary Note 8) The cooling structure for a toroidal coil according to Supplementary Note 7, wherein the toroidal coil includes a core case that houses the core, and the core case has the protrusion.

[0084] (Supplementary Note 9) The cooling structure for a toroidal coil according to Supplementary Note 7, wherein the toroidal coil includes an insulating partition plate that holds the core, and the insulating partition plate has the protrusion.

[0085] (Supplementary Note 10) The cooling structure for a toroidal coil according to Supplementary Note 1, further comprising a leaf spring, the leaf spring being fixed to the metal housing, and the toroidal coil being pressed against the metal housing by the elastic force of the leaf spring.

[0086] (Supplementary Note 11) An outdoor unit for an air conditioning device equipped with the cooling structure for a toroidal coil described in any one of Supplementary Notes 1 to 10, the outdoor unit comprising: a blower chamber in which an outdoor unit fan for blowing air is arranged; a machine chamber in which the printed wiring board is arranged; and a partition plate separating the blower chamber and the machine chamber, the partition plate of the outdoor unit being the metal casing.

[0087] 1 outdoor unit, 2 compressor, 3 heat exchanger, 4 circuit board mounting plate, 5 outdoor unit fan, 6 machine room, 7 blower room, 8 partition plate, 9 printed wiring board, 10 toroidal coil, 11 core, 12 core case, 13 winding, 14 insulating partition plate, 15 protrusion, 17 thermal grease, 18a wiring end, 18b protrusion, 19 crimp terminal, 21 terminal block, 23 heat sink, 24a first thermal conduction sheet, 24b second thermal conduction sheet, 50 retainer plate, 51 pillar, 53 spring screw, 53a spring, 54 leaf spring, 100 toroidal coil cooling structure, FS surface, H through hole, RS back surface.

Claims

1. An outdoor unit of an air conditioner equipped with a cooling structure for a toroidal coil, The cooling structure of the toroidal coil includes: A toroidal coil including a core and a winding wound around the core; a printed wiring board on which the toroidal coil is mounted and which includes a front surface and a back surface; a metal housing disposed on the opposite side of the back surface of the printed wiring board from the front surface; A thermal grease is disposed between the toroidal coil and the metal housing; A column supported by the metal housing; a presser plate connected to the pillar and sandwiching the toroidal coil between the presser plate and the metal housing; the outdoor unit includes a blower chamber in which an outdoor unit fan for blowing air is disposed, a machine chamber in which the printed wiring board is disposed, and a partition plate separating the blower chamber from the machine chamber; The partition plate of the outdoor unit is the metal housing, the winding includes a plurality of protruding portions protruding from the core and extending along the surface of the printed wiring board; the protruding portion of the winding is connected to the printed wiring board so as to move the toroidal coil in a direction in which the toroidal coil overlaps the thermal grease; The pressing plate is configured to press the toroidal coil against the thermal grease, the printed wiring board has an opening; The toroidal coil is disposed within the opening, The plurality of protruding portions are extended in at least two directions and connected to the printed wiring board, the printed wiring board is provided away from the partition plate, and an end of the printed wiring board is provided within a range facing the core of the toroidal coil, The partition plate on which the toroidal coil is disposed is disposed in a position facing the outdoor unit fan.

2. The cooling structure of the toroidal coil further includes a heat sink and a first thermal conductive sheet, the heat sink is sandwiched between the thermal grease and the first thermally conductive sheet, The outdoor unit for an air conditioner according to claim 1 , wherein the first thermally conductive sheet is sandwiched between the heat sink and the metal housing.

3. The cooling structure of the toroidal coil further includes a second thermal conductive sheet, the second thermally conductive sheet is sandwiched between the pressing plate and the toroidal coil, The outdoor unit for an air conditioner according to claim 2 , wherein the toroidal coil is pressed against the thermal grease by a repulsive force of the second thermally conductive sheet.

4. The cooling structure of the toroidal coil further comprises a spring-loaded screw; The presser plate is held on the pillar by the spring-loaded screw, the spring-loaded screw includes a spring; 2. The outdoor unit for an air conditioner according to claim 1, wherein the pressing plate is pressed against the toroidal coil by a repulsive force of the spring.

5. A through hole is provided at the center of the toroidal coil in a plan view, The outdoor unit for an air conditioner according to claim 1 , wherein the pillar is inserted into the through hole.

6. The outdoor unit for an air conditioner according to claim 1 , wherein the toroidal coil is disposed outside an outer edge of the printed wiring board.

7. the toroidal coil includes a protrusion protruding toward the metal housing, The outdoor unit for an air conditioner according to claim 1 , wherein the protruding portion is supported by the metal housing so that the winding is spaced apart from the metal housing, and is made of an insulating material.

8. The toroidal coil includes a core case that houses the core, The outdoor unit for an air conditioner according to claim 7 , wherein the core case has the protrusion.

9. The toroidal coil includes an insulating partition plate that holds the core, The outdoor unit for an air conditioner according to claim 7 , wherein the insulating partition plate has the protrusion.

10. The cooling structure of the toroidal coil further comprises a leaf spring, The leaf spring is fixed to the metal housing, The outdoor unit for an air conditioner according to claim 1 , wherein the toroidal coil is pressed against the metal housing by the elastic force of the leaf spring.