Electrical component box

Abstract

Provided is an electrical component box which simultaneously achieves safety and cooling inside the electrical component box. An electrical component box 70 which is installed in a heat pump unit 100 and internally includes an electrical component is provided with an inner box 50 and an outer box 60. The inner box 50 stores a printed circuit board 43 mounting the electrical component and has a hermetic structure. The outer box 60 covers the inner box 50. In the electrical component box 70, inflow of a gas to the inside of the inner box 50 is suppressed and hence contact of air containing, for example, a contaminant or a flammable gas with an electrode of the electrical component is also suppressed.

Description

Electrical equipment box

[0001] The present invention relates to an electrical component box mounted in a heat source unit of a refrigeration device.

[0002] As an example of the structure of an electrical equipment box for accommodating electrical components, Patent Document 1 (JP 2008-196767 A) discloses an electrical equipment box with a double structure consisting of an inner box and an outer box, in which an opening is provided in the inner box to allow air to flow in and cool the inside of the inner box.

[0003] However, in the electrical equipment box described above, air flowing into the outer box flows into the interior of the inner box through the opening, and there is a risk of fire if air containing flammable gas flows in. Therefore, there is a demand for an electrical equipment box that combines safety and cooling of the interior of the electrical equipment box.

[0004] The electrical equipment box according to a first aspect is an electrical equipment box mounted on a heat source unit of a refrigeration device and having electrical components therein, and includes an inner box and an outer box. The inner box houses a board on which the electrical components are mounted and has a sealed structure. The outer box covers the inner box.

[0005] In this electrical equipment box, the inflow of gas into the interior of the inner box is suppressed, and therefore, air containing pollutants or flammable gases is also suppressed from coming into contact with the electrodes of the electrical components.

[0006] An electrical component box according to a second aspect is the electrical component box according to the first aspect, wherein the interior of the heat source unit is divided by a partition plate into a machine chamber and a fan chamber. A compressor is disposed in the machine chamber. A fan and a heat exchanger are disposed in the fan chamber. The electrical component box is disposed in the fan chamber.

[0007] In this electrical equipment box, assuming a refrigerant leak occurs in a heat source unit that uses a flammable refrigerant, for example, contact between the flammable refrigerant and electrical components can be reduced by placing the electrical equipment box in the blower room, where the flammable refrigerant is more likely to be quickly diffused by the blower and the gas concentration is more likely to be low, rather than in the machine room, where the flammable refrigerant is more likely to become trapped.

[0008] An electrical component box according to a third aspect is the electrical component box according to the second aspect, wherein the outer box has an opening for introducing outside air.

[0009] In this electrical equipment box, the temperature inside the inner box, which has a sealed structure, tends to rise easily, so the inner box can be cooled from the outside by introducing outside air from the outer box.

[0010] The electrical equipment box of the fourth aspect is the electrical equipment box of the third aspect, wherein the opening is provided at the farthest part of the outer box from the machine room and on the front side of the outer box when the outer box is viewed from the front of the blower room.

[0011] In this electrical equipment box, for example, in the case of a heat source unit that uses a flammable refrigerant and refrigerant leaking from the machine compartment, if the opening is located away from the machine compartment, the flammable refrigerant is less likely to be drawn in. Also, in the blower compartment, air drawn in from the back is blown out forward from the front outlet, so if the opening is located at the front, air containing the flammable refrigerant is less likely to be drawn in.

[0012] An electrical component box according to a fifth aspect is the electrical component box according to any one of the first to fourth aspects, wherein a heat sink is attached to the inner box.

[0013] In this electrical equipment box, the temperature inside the inner box, which has a sealed structure, tends to rise easily, so by cooling the inside of the inner box with a heat sink, it is possible to suppress the temperature rise inside the inner box.

[0014] An electrical component box according to a sixth aspect is the electrical component box according to the fifth aspect, wherein the heat sink exchanges heat between the interior of the inner box and the interior of the outer box.

[0015] In this electrical equipment box, heat inside the inner box is transferred to the inside of the outer box, facilitating cooling of the inside of the inner box.

[0016] An electrical component box according to a seventh aspect is the electrical component box according to the fifth aspect, wherein the heat sink exchanges heat between the inside of the inner box and the outside of the outer box.

[0017] In this electrical equipment box, heat inside the inner box is transferred to the outside of the outer box, facilitating cooling of the inside of the inner box.

[0018] An eighth aspect of the present invention is the electrical component box of the seventh aspect, wherein an intelligent power module is mounted on the board, and the heat sink exchanges heat between the intelligent power module and the outside of the outer box.

[0019] In this electrical equipment box, the heat from the intelligent power module, which is a heat source, is transferred to the outside of the outer box, thereby facilitating the cooling of the intelligent power module.

[0020] An electrical component box according to a ninth aspect is the electrical component box according to any one of the third to eighth aspects, further comprising a fan that generates an airflow.

[0021] In this electrical equipment box, forced convection of air occurs inside, which promotes cooling within the electrical equipment box.

[0022] An electrical component box according to a tenth aspect is the electrical component box according to the ninth aspect, wherein the fan is disposed inside the inner box.

[0023] In this electrical equipment box, forced convection of air occurs inside the inner box, facilitating cooling of the inside of the inner box.

[0024] An electrical component box according to an eleventh aspect is the electrical component box according to the ninth aspect, wherein the fan is disposed in the opening or in a space sandwiched between the inner box and the outer box.

[0025] In this electrical equipment box, forced convection of air occurs in the space between the inner box and the outer box, facilitating cooling of the inside of the outer box.

[0026] An electrical equipment box according to a twelfth aspect is the electrical equipment box according to any one of the first to eleventh aspects, wherein the inner box is made of aluminum or an aluminum alloy.

[0027] In this electrical equipment box, the temperature inside the sealed inner box is prone to rise, so by making the inner box out of aluminum or an aluminum alloy, the heat dissipation properties of the inner box are improved and the temperature rise inside the inner box is suppressed.

[0028] An electrical component box according to a thirteenth aspect is the electrical component box according to any one of the first to twelfth aspects, wherein the outer box is made of resin.

[0029] In this electrical equipment box, the outer box comes into contact with air whose temperature has risen due to heat exchange in the heat exchanger, so by forming the outer box from resin with lower thermal conductivity than metal, the heat insulation properties of the outer box are improved and the temperature rise inside the outer box is suppressed.

[0030] An electrical component box according to a fourteenth aspect is the electrical component box according to any one of the first to thirteenth aspects, further comprising a heat pipe for cooling the inside of the inner box.

[0031] This electrical equipment box has a higher cooling performance than air cooling, and is therefore highly effective in suppressing temperature rises inside the inner box.

[0032] An electrical component box according to a fifteenth aspect is the electrical component box according to any one of the first to fourteenth aspects, wherein the refrigerant of the refrigeration device is a flammable refrigerant.

[0033] Even if a flammable refrigerant leaks from this electrical equipment box, the inflow of the flammable refrigerant into the sealed inner box is prevented, so the risk of fire due to contact with electrical components is extremely low.

[0034] An electrical equipment box according to a sixteenth aspect is the electrical equipment box according to any one of the first to fifteenth aspects, wherein the inner box has a box body and a lid. The box body forms a storage space for the circuit board. The lid overlaps the box body to close the storage space. The overlapping portion between the box body and the lid includes a first flange, a second flange, and a sealing member. The first flange is provided on the box body. The second flange is provided on the lid so as to overlap the first flange. The sealing member seals between the first flange and the second flange.

[0035] In this electrical equipment box, the airtightness of the inner box is improved by the presence of a seal member between the box body and the flange of the lid.

[0036] An electrical component box according to a seventeenth aspect is the electrical component box according to the sixteenth aspect, wherein the overlapping portion further includes a fastening member. The fastening member fastens the first flange and the second flange together in a direction that compresses the seal member.

[0037] In this electrical equipment box, the seal member sandwiched between the flanges of the box body and the lid is compressed and tightly contacts each flange, further improving the airtightness of the inner box.

[0038] An electrical equipment box according to an eighteenth aspect is the electrical equipment box according to the sixteenth or seventeenth aspect, wherein the inner box further has a through hole and a cable gland. The through hole is a hole through which a wire passes. The cable gland is inserted into the through hole together with the wire to seal between the through hole and the wire.

[0039] In this electrical equipment box, the gap between the through hole and the wiring is sealed, thereby further improving the airtightness of the inner box.

[0040] A heat source unit according to a nineteenth aspect includes the electrical component box according to any one of the first to eighteenth aspects.

[0041] Fig. 1 is an external perspective view of a heat pump unit, which is a refrigeration device equipped with an electrical component box according to a first embodiment of the present disclosure; Fig. 2 is a perspective view of the inside of the heat pump unit of Fig. 1; Fig. 3 is a cross-sectional view of the electrical component box according to the first embodiment of the present disclosure; Fig. 4 is an enlarged cross-sectional view of an inner box; Fig. 5 is a cross-sectional view of an electrical component box according to a second embodiment; Fig. 6 is a cross-sectional view of an electrical component box according to a third embodiment;

[0042] <First embodiment> (1) Configuration of refrigeration device Fig. 1 is an external perspective view of a heat pump unit 100, which is a refrigeration device equipped with an electrical component box 70 according to a first embodiment of the present disclosure. In Fig. 1, a portion of the front surface of a casing 80 is intentionally cut away to allow a fan 29 to be seen.

[0043] 1, the heat pump unit 100 is used in a domestic hot water supply, but the heat pump unit 100 can be used in many other applications.

[0044] Fig. 2 is a perspective view of the inside of the heat pump unit 100 of Fig. 1. In Fig. 2, most of the components of the heat pump unit 100 are housed in a casing 80.

[0045] The interior of the casing 80 is divided by a partition plate 87 into a machine chamber 88 on the right side as viewed from the front in FIG. 2 and a blower chamber 89 on the left side.

[0046] The machine chamber 88 houses the compressor 11. The blower chamber 89 houses the first heat exchanger 15 and a fan 29 that blows air to the first heat exchanger 15.

[0047] The heat pump unit 100 has a refrigerant circuit in which a compressor 11, a first heat exchanger 15, a pressure reducing valve (not shown), and a second heat exchanger (not shown) are connected in a circular arrangement. The heat pump unit 100 circulates a refrigerant through the refrigerant circuit to transfer thermal energy between the first heat exchanger 15 and the second heat exchanger. The refrigerant is preferably a hydrocarbon such as R290, which has low ozone depletion potential and low global warming potential.

[0048] In the heat pump unit 100, an electrical component box 70 is disposed above the fan 29 in the blower chamber 89. Although the contents of the electrical component box 70 are not depicted in Fig. 2, in reality, the electrical component box 70 houses a printed circuit board on which electrical components such as a microprocessor, memory, and an intelligent power module are mounted. The microprocessor controls the operating frequency of the compressor 11, monitors the discharge temperature of the compressor 11, and controls the opening degree of the pressure reducing valve.

[0049] (2) Configuration of Electrical Component Box 70 Fig. 3 is a cross-sectional view of electrical component box 70 according to the first embodiment of the present disclosure. In Fig. 3, electrical component box 70 has a double structure in which inner box 50 is covered with outer box 60.

[0050] Electrical component box 70 is disposed in blower chamber 89. In the event of a flammable refrigerant leak in heat pump unit 100, by disposing electrical component box 70 in blower chamber 89, where the refrigerant is more likely to be quickly diffused by fan 29 and the gas concentration is more likely to be low, than in machine chamber 88, where the refrigerant is more likely to become trapped, contact between the flammable refrigerant and the electrical components in electrical component box 70 can be reduced.

[0051] (2-1) Inner Box 50 Fig. 4 is an enlarged cross-sectional view of the inner box 50. The inner box 50 houses a printed circuit board 43 on which electrical components are mounted, and a first fan 51 that blows air onto the printed circuit board 43. The inner box 50 has a structure in which an inner lid 50b is placed on an inner box main body 50a to close the opening of the inner box main body 50a.

[0052] Both the inner box body 50a and the inner lid 50b are made of aluminum or an aluminum alloy. Because the temperature inside the inner box 50 rises to around 100°C due to heat dissipation from heat-generating components such as the IPM 41, aluminum or an aluminum alloy is desirable to enhance the heat dissipation properties of the inner box 50.

[0053] (2-1-1) Inner Box Main Body 50a The inner box main body 50a has a rectangular hole 50ab penetrating the bottom wall. A first heat sink 62 is attached to the rectangular hole 50ab.

[0054] (2-1-1-1) First Heat Sink 62 The first heat sink 62 is made of aluminum or an aluminum alloy, which has high thermal conductivity.

[0055] The first heat sink 62 has a rectangular parallelepiped first block 62a and a plurality of first fins 62b protruding from the first block 62a. The first block 62a is attached so as to cover the rectangular hole 50ab. The gap between the first block 62a and the rectangular hole 50ab is sealed with a sealant SC.

[0056] (2-1-1-2) Cable Gland 53 Furthermore, the inner box body 50a is provided with a round hole 50ac penetrating the lower part of the side wall. The electrical wiring W is inserted into the cable gland 53 and led from the round hole 50ac into the inner box body 50a.

[0057] The cable gland 53 includes a first bolt portion 531 , a second bolt portion 532 , a first nut portion 541 , a second nut portion 542 , a seal member 551 , and a wedge portion 552 .

[0058] The first bolt portion 531 and the second bolt portion 532 are integrally molded coaxially. A guide hole 53a for passing an electrical wiring W therethrough is formed axially through the first bolt portion 531 and the second bolt portion 532.

[0059] The first bolt portion 531 has an outer diameter of the threads slightly smaller than that of the circular hole 50ac, and is inserted into the circular hole 50ac. The first nut 541 is threaded onto the first bolt portion 531 inserted into the circular hole 50ac, and the first bolt portion 531 and the first nut portion 541 fasten the side wall of the inner box main body 50a together.

[0060] An annular seal member 551 and a wedge portion 552 that annularly covers the outer peripheral surface of the seal member 551 are inserted inside the second bolt portion 532. The inner diameter of the annular seal member 551 is the same as the diameter of the electrical wiring W, and the annular seal member 551 is in close contact with the electrical wiring W.

[0061] When the second nut portion 542 is screwed onto the second bolt portion 532, the wedge portion 552 is compressed in the radial direction, causing the seal member 551 to tightly contact the electrical wiring W. This seals the gap between the electrical wiring W and the inner box 50.

[0062] (2-1-2) Inner lid 50b The inner lid 50b has a rectangular hole 50bc penetrating the top wall. A second heat sink 52 is attached to the rectangular hole 50bc. The second heat sink 52 is made of aluminum or an aluminum alloy, which has high thermal conductivity.

[0063] The second heat sink 52 includes a rectangular parallelepiped second block 52a and multiple second fins 52b protruding from the second block 52a. The second block 52a is attached to close the rectangular hole 50bc. The gap between the second block 52a and the rectangular hole 50bc is sealed with a sealant SC.

[0064] (2-1-3) Overlapping portion 500 The inner box body 50a is provided with a first flange 501 that surrounds the entire periphery of its opening. The inner lid 50b is also provided with a second flange 502 that surrounds the entire periphery of its opening. After the printed circuit board 43 and the first fan 51 are housed inside the inner box body 50a, the second flange 502 of the inner lid 50b is overlapped on the first flange 501 of the inner box body 50a, forming the overlapping portion 500.

[0065] A seal member 503 is disposed between the first flange 501 and the second flange 502. Furthermore, pilot holes for threading tapping screws 504 are provided in advance in the first flange 501 and the second flange 502.

[0066] With the seal member 503 sandwiched between the first flange 501 and the second flange 502, the tapping screw 504 inserted into the prepared hole is further screwed in, thereby tightening the first flange 501 and the second flange 502 in a direction that compresses the seal member 503. As a result, the gap between the first flange 501 and the second flange 502 is sealed.

[0067] (2-1-4) Printed Circuit Board 43 The printed circuit board 43 is a double-sided printed circuit board with a power device mounted on one side thereof. In this embodiment, an intelligent power module (hereinafter referred to as an IPM 41) is mounted on the printed circuit board.

[0068] The surface of the printed circuit board 43 on which the IPM 41 is mounted faces the first block 62a of the first heat sink 62. The height of the printed circuit board 43 is adjusted so that the heat dissipation surface of the IPM 41 is in contact with the first block 62a. Thermal compound or thermal grease is applied between the first block 62a and the heat dissipation surface of the IPM 41.

[0069] The first heat sink 62 exchanges heat between the heat dissipation surface of the IPM 41 and the outside air. Heat from the heat dissipation surface of the IPM 41 moves through the first block 62a to the first fins 62b and is then transferred to the air. As a result, cooling of the IPM 41 is promoted.

[0070] (2-1-5) First Fan 51 The first fan 51 is a cooling fan that blows air onto the printed circuit board 43. Heat-generating components other than the IPM 41 are mounted on the printed circuit board 43, but those that do not generate as much heat as the IPM 41 are cooled by forced convection by the first fan 51.

[0071] 2, the outer box 60 is located above the fan 29 in the blower chamber 89. The outer box 60 has a structure in which an outer lid 60b is placed on an outer box body 60a to close the upper opening of the outer box body 60a.

[0072] Both the outer box body 60a and the outer lid 60b are molded from a synthetic resin such as ABS resin. The temperature around the outer box 60 rises to around 60°C due to the heat radiation from the first heat exchanger 15, so synthetic resin is used to improve thermal insulation between the outer box 60 and the interior. However, the outer box body 60a and the outer lid 60b may also be molded from foamed polypropylene, which has good thermal insulation properties.

[0073] (2-2-1) Outer Box Body 60a The outer box body 60a has a rectangular hole 60ab penetrating the bottom wall. As shown in Fig. 3, the outer box body 60a is a container that covers the inner box 50, and the first fins 62b of the first heat sink 62 protruding from the inner box 50 are passed through the rectangular hole 60ab and exposed to the fan chamber 89.

[0074] A protrusion 60ac is provided on the periphery of the rectangular hole 60ab. A recess 62ac is provided on the bottom surface of the first block 62a of the first heat sink 62. The inner box 50 is assembled so that the recess 62ac fits into the protrusion 60ac.

[0075] 2, an opening 60ad is provided in the front wall of the outer box 60. The opening 60ad is large enough to occupy most of the front surface of the outer box body 60a to allow for easy circulation of outside air. Two positioning protrusions 60ae are provided at positions a predetermined distance inward from the opening 60ad.

[0076] By aligning the inner box 50 so that it fits along this protrusion 60ae and so that the first fin 62b of the first heat sink 62 protruding from the inner box 50 passes through the square hole 60ab, the convex portion 60ac fits into the concave portion 62ac, and the inner box 50 is incorporated into the outer box main body 60a.

[0077] A fan mounting hole 60af is provided in the side wall of the outer box body 60a, in which the second fan 61 is installed. An introduction hole 60ag is provided in the side wall opposite the fan mounting hole 60af, in order to introduce the electrical wiring W into the outer box 60.

[0078] The fan mounting hole 60af is preferably provided on the side wall of the outer box 60 that is farthest from the partition plate 87, or on the front side of the outer box 60 that is farthest from the partition plate 87 and is also when the outer box is viewed from the front of the blower chamber 89.

[0079] This is because, assuming a case in which a flammable refrigerant leaks from the machine compartment 88, the refrigerant is less likely to be sucked in if the fan mounting hole 60af is away from the partition plate 87. Also, in the blower compartment 89, air sucked in from the back is blown forward from the front air outlet, so air containing a flammable refrigerant is less likely to be sucked in if the fan mounting hole 60af is located on the side wall farthest from the partition plate 87, or on the part of the outer box 60 farthest from the machine compartment 88 and in front of the outer box 60. In the first embodiment, the fan mounting hole 60af is provided on the side wall of the outer box 60 farthest from the partition plate 87, as shown in FIG. 3 .

[0080] (2-2-2) Outer lid 60b The outer lid 60b is a lid that closes the top opening of the outer box body 60a. A rib 60bc that protrudes downward is provided at the end of the outer lid 60b so as to surround the periphery of the top opening. In addition, two claws 60bd are provided on the front surface of the outer lid 60b in front view in FIG. 2.

[0081] As shown in FIG. 2, the claw portion 60bd engages with the edge of the opening 60ad of the outer box body 60a to fix the outer lid 60b to the outer box body 60a.

[0082] (2-2-3) Second Fan 61 The second fan 61 is a cooling fan that takes in outside air from the opening 60ad and sends it to the second heat sink 52 that protrudes from the top of the inner box 50. The second heat sink 52 exchanges heat between the inside of the inner box 50 and the outside air sent from the second fan 61.

[0083] Since the temperature inside the inner box 50 having a sealed structure tends to rise easily, the temperature rise inside the inner box 50 can be suppressed by cooling the inside of the inner box 50 with the second heat sink 52 .

[0084] (3) Airtightness of Inner Box 50 As already explained, in the inner box 50, the gap between the first block 62a and the rectangular hole 50ab is sealed with the sealant SC, the gap between the electrical wiring W and the inner box 50 is sealed with the cable gland 53, and the gap between the second block 52a and the rectangular hole 50bc is sealed with the sealant SC.

[0085] Furthermore, the gap between the first flange 501 and the second flange 502 of the overlapping portion 500 is sealed by a sealing member 503 .

[0086] The above-described configuration maintains a high degree of sealing from the outside inside the inner box 50. Specifically, even if the inner box 50 is left in the gas refrigerant R290, which is a flammable refrigerant, the concentration of the gas refrigerant that enters the inner box 50 is ¼ or less of the explosive concentration of R290.

[0087] Therefore, even if the flammable refrigerant leaks from the machinery compartment 88 and enters the interior of the outer box 60 of the electrical component box 70, the flammable refrigerant will not reach an explosive concentration inside the inner box 50. This provides a high level of safety.

[0088] (4) Features of the First Embodiment (4-1) In the electrical component box 70, the inner box 50 has a sealed structure, which prevents gas from flowing into the inner box 50. This also prevents air containing pollutants or flammable gases from coming into contact with the electrodes of the electrical components.

[0089] (4-2) The electrical component box 70 is disposed in the blower chamber 89. In the event of a flammable refrigerant leak in the heat pump unit 100, by disposing the electrical component box 70 in the blower chamber 89, where the refrigerant is more likely to be quickly diffused by the fan 29 and have a lower gas concentration, rather than in the machine chamber 88, where the refrigerant is more likely to become trapped, it is possible to prevent the flammable refrigerant from coming into contact with the electrical components in the electrical component box 70.

[0090] (4-3) In the electrical equipment box 70, the outer box 60 has an opening 60ad for introducing outside air and a fan mounting hole 60af. Since the temperature inside the sealed inner box 50 tends to rise, the inner box 50 can be cooled from the outside by introducing outside air through the outer box 60.

[0091] (4-4) The opening 60ad and / or the fan mounting hole 60af are provided on the side wall of the outer box 60 that is farthest from the machine chamber 88, or on the front side of the outer box 60 that is farthest from the machine chamber 88 and is also when the outer box is viewed from the front of the blower chamber 89.

[0092] Assuming that a flammable refrigerant leaks from the machinery chamber 88, even if the refrigerant leaks from the machinery chamber 88, the refrigerant is unlikely to be sucked in if the opening 60ad and / or the fan mounting hole 60af are located away from the machinery chamber 88.

[0093] In addition, in the blower chamber 89, air sucked in from the back is blown out forward from the outlet on the front, so air containing flammable refrigerant is less likely to be sucked in if it is on the side wall farthest from the machine chamber 88, or on the part of the outer box 60 farthest from the machine chamber 88 and in front of the outer box 60.

[0094] (4-5) In the electrical component box 70, the second heat sink 52 exchanges heat between the inside of the inner box 50 and the outside air sent from the second fan 61. Since the temperature inside the inner box 50, which has an airtight structure, tends to rise easily, the second heat sink 52 cools the inside of the inner box 50, thereby suppressing the temperature rise inside the inner box 50.

[0095] (4-6) In this electrical component box 70, the first heat sink 62 exchanges heat between the heat dissipation surface of the IPM 41 and the outside air. Heat from the heat dissipation surface of the IPM 41 moves through the first block 62a to the multiple first fins 62b and is then transferred to the air. As a result, cooling of the IPM 41 is promoted.

[0096] (4-7) In this electrical component box 70, heat-generating components other than the IPM 41 are mounted on the printed circuit board 43, but those that do not generate as much heat as the IPM 41 are cooled by forced convection by the first fan 51.

[0097] (4-8) In this electrical equipment box 70, the second fan 61 takes in outside air through the opening 60ad and blows it to the second heat sink 52 protruding from the top of the inner box 50. The second heat sink 52 exchanges heat between the inside of the inner box 50 and the outside air sent from the second fan 61, thereby suppressing a rise in temperature inside the inner box 50.

[0098] (4-9) In the electrical equipment box 70, the temperature inside the sealed inner box 50 is likely to rise. Therefore, by making the inner box 50 out of aluminum or an aluminum alloy, the heat dissipation properties of the inner box 50 are improved, and the temperature rise inside the inner box 50 is suppressed.

[0099] (4-10) In the electrical equipment box 70, the outer box 60 comes into contact with air whose temperature has risen due to heat exchange in the first heat exchanger 15. Therefore, by forming the outer box 60 from a resin whose thermal conductivity is lower than that of metal, the insulating properties of the outer box 60 are improved, and the temperature rise inside the outer box 60 is suppressed.

[0100] (4-11) In this electrical component box 70, the gap between the first block 62a and the rectangular hole 50ab in the inner box 50 is sealed with a sealant SC. The gap between the electrical wiring W and the inner box 50 is sealed with a cable gland 53. The gap between the second block 52a and the rectangular hole 50bc is also sealed with a sealant SC. Furthermore, the gap between the first flange 501 and the second flange 502 of the overlapping portion 500 is sealed with a sealant 503.

[0101] Therefore, the inner box 50 is highly airtight and prevents the inflow of flammable refrigerant into the inner box 50, so the risk of fire due to contact with electrical components is extremely low.

[0102] Second Embodiment (1) Configuration of Electrical Component Box 70 Fig. 5 is a cross-sectional view of an electrical component box 70 according to a second embodiment. This embodiment differs from the first embodiment in that a heat pipe 56 is installed inside the inner box 50. In accordance with the installation of the heat pipe 56, the inner box body of the inner box 50 and the outer box body of the outer box 60 have been modified.

[0103] On the other hand, there are no changes to the inner lid 50b of the inner box 50, the configuration of the cable gland 53, the configuration of the first fan 51, the configuration of the outer lid 60b of the outer box 60, and the configuration of the overlapping portion 500. Therefore, here, only the inner box main body 50x and heat pipe 56 of the inner box 50 and the outer box main body 60x of the outer box 60, which are changed from the first embodiment, will be described.

[0104] (1-1) Inner Box Body 50x The inner box body 50x has a third heat sink 55. The third heat sink 55 is made of aluminum or an aluminum alloy, which has high thermal conductivity. The third heat sink 55 has a third block 55a and a plurality of third fins 55b protruding from the third block 55a.

[0105] The third block 55a forms the entire bottom wall of the inner box body 50x. After joining, the corners between the third block 55a and the side walls of the inner box body 50x are sealed with a sealant SC.

[0106] As shown in FIG. 5, the first fan 51 blows air from the left side of the third fin 55 b , so that heat exchange occurs between the air inside the inner box 50 and the air inside the outer box 60 .

[0107] An introduction hole 50xa is provided in the side wall of the inner box body 50x for introducing the heat pipe 56 into the inner box 50. The gap between the heat pipe 56 and the introduction hole 50xa is sealed with a seal material SC.

[0108] (1-2) Heat Pipe 56 The heat pipe 56 has an evaporation section 561 located inside the inner box 50 and a condensation section 562 located in the machine chamber 88. A heat medium is sealed inside the heat pipe 56.

[0109] The evaporation section 561 is attached to one surface of the first heat transfer plate 57. The heat dissipation surface of the IPM 41 is attached to the surface of the first heat transfer plate 57 opposite to the surface on which the evaporation section 561 is attached.

[0110] A thermal compound or thermal grease is applied between the evaporation portion 561 and the first heat transfer plate 57 and between the first heat transfer plate 57 and the heat dissipation surface of the IPM 41 .

[0111] The condenser section 562 is attached to a fourth heat sink 84 disposed in a machine chamber 88. In addition, a refrigerant pipe 90 of the refrigerant circuit is attached to the fourth heat sink 84. The fourth heat sink 84 allows heat exchange between the heat medium inside the condenser section 562 and the refrigerant flowing inside the refrigerant pipe 90.

[0112] The heat medium of the heat pipe 56 absorbs heat and evaporates into a gas in the evaporation section 561. The gasified heat medium moves to the condensation section 562, where it releases heat and returns to a liquid. This operation cools the IPM 41.

[0113] As shown in FIG. 5 , the first fan 51 blows air from the left side of the first heat transfer plate 57 , so that the air cooled on the surface of the first heat transfer plate 57 circulates inside the inner box 50 .

[0114] (1-3) Outer Box Main Body 60x An introduction hole 60xa is provided in the side wall of the outer box main body 60x to introduce the heat pipe 56 into the outer box 60. The second embodiment does not have a configuration in which the IPM 41 in the inner box 50 is cooled by the first heat sink 62 of the first embodiment, and therefore does not require the first heat sink 62 that penetrates the inner box 50 and the outer box 60. Therefore, the outer box main body 60x does not require a through hole for exposing the heat sink to the outside.

[0115] (2) Airtightness of the Inner Box 50 As already explained, the corners between the third block 55a and the sidewall of the inner box body 50x and the gap between the heat pipe 56 and the inlet hole 50xa are sealed with the seal material SC. In addition, the gap between the electrical wiring W and the inner box 50 is sealed with the cable gland 53, and the gap at the overlapping portion 500 is sealed with the seal member 503.

[0116] The above-described configuration maintains a high degree of sealing from the outside inside the inner box 50. Specifically, even if the inner box 50 is left in the gas refrigerant R290, which is a flammable refrigerant, the concentration of the gas refrigerant that enters the inner box 50 is ¼ or less of the explosive concentration of R290.

[0117] Therefore, even if the flammable refrigerant leaks from the machinery compartment 88 and enters the interior of the outer box 60 of the electrical component box 70, the flammable refrigerant will not reach an explosive concentration inside the inner box 50. This provides a high level of safety.

[0118] (3) Features of the Second Embodiment The electrical component box 70 according to the second embodiment inherits the features of the first embodiment. In addition, the electrical component box 70 further includes a heat pipe 56 that cools the interior of the inner box 50, which provides higher cooling performance than air cooling and effectively suppresses temperature increases inside the inner box 50.

[0119] 6 is a cross-sectional view of an electrical component box 70 according to a third embodiment. This embodiment differs from the first embodiment in that a heat pipe 56 is installed inside the inner box 50. With the installation of the heat pipe 56, the orientations of the inner box body and inner lid of the inner box 50, the outer box body of the outer box 60, and the printed circuit board 43 are changed.

[0120] On the other hand, the configuration of the cable gland 53, the configuration of the first fan 51, the configuration of the outer lid 60b of the outer box 60, and the configuration of the overlapping portion 500 remain unchanged.

[0121] Therefore, here, the inner box body 50y, inner lid 50z, and outer box body 60y of the outer box 60, which are modified from the first embodiment, will be described.

[0122] (1-1) Inner Box Body 50y The inner box body 50y is a box-shaped container that opens upward. The inner box body 50y contains the printed circuit board 43, the heat pipe 56, the second heat transfer plate 58, and the fifth heat sink 65. Electrical wiring W is also introduced into the inner box body 50y via a cable gland 53.

[0123] (1-2) Inner Lid 50z An introduction hole 50za is provided in the side wall of the inner lid 50z for introducing the heat pipe 56 into the inner box 50. The gap between the heat pipe 56 and the introduction hole 50za is sealed with a seal material SC.

[0124] (1-3) Printed Circuit Board 43 The printed circuit board 43 is placed with the surface on which the IPM 41 is mounted facing up. A second heat transfer plate 58 is attached to the heat dissipation surface of the IPM 41. The second heat transfer plate 58 is made of aluminum or an aluminum alloy, which has high thermal conductivity. A thermal compound or thermal grease is applied between the second heat transfer plate 58 and the IPM 41.

[0125] (1-4) Fifth Heat Sink 65 The fifth heat sink 65 is made of aluminum or an aluminum alloy, which has high thermal conductivity. The fifth heat sink 65 has a fifth block 65a and a plurality of fifth fins 65b protruding from the fifth block 65a.

[0126] (1-5) Heat Pipe 56 The heat pipe 56 has an evaporation section 561 located inside the inner box 50 and a condensation section 562 located in the machine chamber 88. A heat medium is sealed inside the heat pipe 56.

[0127] The evaporation portion 561 is sandwiched between one surface of the second heat transfer plate 58 (the surface opposite to the surface on which the IPM 41 is mounted) and one surface of the fifth heat sink 65 .

[0128] The condenser section 562 is attached to a fourth heat sink 84 disposed in a machine chamber 88. In addition, a refrigerant pipe 90 of the refrigerant circuit is attached to the fourth heat sink 84. The fourth heat sink 84 allows heat exchange between the heat medium inside the condenser section 562 and the refrigerant flowing inside the refrigerant pipe 90.

[0129] The heat medium of the heat pipe 56 absorbs heat and evaporates into a gas in the evaporation section 561. The gasified heat medium moves to the condensation section 562, where it releases heat and returns to a liquid. This operation cools the IPM 41.

[0130] 6, the first fan 51 blows air from the left side of the fifth heat sink 65, so that heat is exchanged between the air circulating inside the inner box 50 and the fifth heat sink 65. As a result, the inside of the inner box 50 is cooled.

[0131] (1-6) Outer Box Main Body 60x An introduction hole 60za is provided in the side wall of the outer box main body 60x to introduce the heat pipe 56 into the outer box 60. The third embodiment does not have the configuration in which the IPM 41 in the inner box 50 is cooled by the first heat sink 62 of the first embodiment, and therefore does not require the first heat sink 62 that penetrates the inner box 50 and the outer box 60. Therefore, the outer box main body 60x does not require a through hole for exposing the heat sink to the outside.

[0132] (2) Sealing of the Inner Box 50 As already explained, the gap between the heat pipe 56 and the inlet hole 50za is sealed with the seal material SC. In addition, the gap between the electrical wiring W and the inner box 50 is sealed with the cable gland 53, and the gap at the overlapping portion 500 is sealed with the seal member 503.

[0133] The above-described configuration maintains a high degree of sealing from the outside inside the inner box 50. Specifically, even if the inner box 50 is left in the gas refrigerant R290, which is a flammable refrigerant, the concentration of the gas refrigerant that enters the inner box 50 is ¼ or less of the explosive concentration of R290.

[0134] Therefore, even if the flammable refrigerant leaks from the machinery compartment 88 and enters the interior of the outer box 60 of the electrical component box 70, the flammable refrigerant will not reach an explosive concentration inside the inner box 50. This provides a high level of safety.

[0135] (3) Features of the Third Embodiment The electrical component box 70 according to the third embodiment inherits the features of the first embodiment. In addition, the electrical component box 70 further includes a heat pipe 56 that cools the interior of the inner box 50, which provides higher cooling performance than air cooling and effectively suppresses temperature increases inside the inner box 50.

[0136] Although the embodiments of the present disclosure have been described above, it will be understood that various changes in form and details can be made without departing from the spirit and scope of the present disclosure as defined in the claims.

[0137] The sealed structure of the electrical component box 70 is not limited to the heat pump unit 100, but can be widely used in devices that use a flammable refrigerant.

[0138] DESCRIPTION OF SYMBOLS 41 IPM (Intelligent Power Module) 43 Printed circuit board (substrate) 50 Inner box 50a Inner box body (box body) 50ac (through hole) 50b Inner lid (lid portion) 50x Inner box body (box body) 50y Inner box body (box body) 50z Inner lid (lid portion) 51 First fan 52 Second heat sink 53 Cable gland 56 Heat pipe 60 Outer box 60ad Opening (opening) 60af Fan mounting hole (opening) 61 Second fan 62 First heat sink 70 Electrical equipment box 87 Partition plate 88 Machine room 89 Fan room 100 Heat source unit 500 Overlapping portion 501 First flange 502 Second flange 503 Sealing member

[0139] Japanese Patent Application Laid-Open No. 2008-196767

Claims

1. An electrical equipment box mounted on a heat source unit (100) of a refrigeration device and having electrical components therein, an inner box (50) having a sealed structure that houses a board (43) on which the electrical components are mounted; An outer box (60) that covers the inner box (50); Equipped with Electrical equipment box (70).

2. The interior of the heat source unit (100) is partitioned by a partition plate (87) into a machine room (88) in which a compressor (11) is disposed and a blower room (89) in which a blower (29) and a heat exchanger (15) are disposed, The electrical equipment box (70) is arranged in the blower room (89). The electrical component box (70) of claim 1.

3. The outer box (60) has openings (60ad, 60af) for introducing outside air. The electrical component box (70) of claim 2.

4. The opening (60ad) is provided at a portion of the outer box (60) farthest from the machine room (88) and on the front surface of the outer box (60) when the outer box (60) is viewed from the front of the blower room (89). An electrical component box (70) according to claim 3.

5. A heat sink (52, 62) is attached to the inner box (50). An electrical component box (70) according to any one of claims 1 to 4.

6. The heat sink (52) performs heat exchange between the inside of the inner box (50) and the inside of the outer box (60).

6. An electrical component box (70) according to claim 5.

7. The heat sink (62) exchanges heat between the inside of the inner box (50) and the outside of the outer box (60).

6. An electrical component box (70) according to claim 5.

8. An intelligent power module (41) is mounted on the substrate (43), The heat sink (62) exchanges heat between the intelligent power module (41) and the outside of the outer box (60).

8. An electrical component box (70) according to claim 7.

9. Further provided is a fan (51, 61) for generating an air flow. An electrical component box (70) according to claim 3 or claim 4.

10. The fan (51) is disposed inside the inner box (50). The electrical component box according to claim 9.

11. The fan (61) is disposed in the opening (60ad, 60af) or in a space sandwiched between the inner box (50) and the outer box (60).

10. An electrical component box (70) according to claim 9.

12. The inner box (50) is made of aluminum or an aluminum alloy. An electrical component box (70) according to any one of claims 1 to 4.

13. The outer box (60) is made of resin. An electrical component box (70) according to any one of claims 1 to 4.

14. Further provided is a heat pipe (56) for cooling the inside of the inner box (50). An electrical component box (70) according to any one of claims 1 to 4.

15. The refrigerant of the refrigeration device is a flammable refrigerant. An electrical component box (70) according to any one of claims 1 to 4.

16. The inner box (50) is a box body (50a, 50x, 50y) that forms a storage space for the substrate (43); a lid portion (50b, 50z) that overlaps with the box body (50a) and closes the storage space; and The overlapping portion (500) between the box body (50a, 50x, 50y) and the lid portion (50b, 50z) is a first flange (501) provided on the box body (50a, 50x, 50y); a second flange (502) provided on the lid portion (50b, 50z) so as to overlap the first flange (501); a sealing member (503) that seals between the first flange (501) and the second flange (502); Including, An electrical component box (70) according to any one of claims 1 to 4.

17. The overlapping portion (500) further includes a fastening member (504) that fastens the first flange (501) and the second flange (502) in a direction that compresses the sealing member (503).

17. An electrical component box (70) according to claim 16.

18. The inner box (50) is a through hole (50ac) through which a wiring (W) passes; a cable gland (53) that is inserted into the through hole (50ac) together with the wiring (W) and seals between the through hole (50ac) and the wiring (W); further comprising 17. An electrical component box (70) according to claim 16.

19. The electrical equipment box (70) according to any one of claims 1 to 4 is provided. A heat source unit (100).