JP7102803B2 - Outdoor unit of air conditioner - Google Patents

Description

The present invention relates to an outdoor unit of an air conditioner that cools a power device mounted on an electrical component module with a cooler.

As shown in FIG. 12, a general air conditioner includes an outdoor unit 10 installed outdoors and an indoor unit 20 installed indoors. The outdoor unit 10 and the indoor unit 20 are connected by a refrigerant pipe 30 to form a steam compression refrigeration cycle.

The outdoor unit 10 is supplied with lubricating oil from an outdoor heat exchanger 11 that exchanges heat between outdoor air and a refrigerant, a blower fan 11F, a compressor 12 that compresses the refrigerant, and a mixed fluid of the lubricating oil and the refrigerant discharged from the compressor 12. An oil separator 13 for separation, an expansion valve 14 for expanding the inflowing refrigerant to reduce the pressure to a predetermined pressure, an accumulator 15 for separating the inflowing refrigerant into gas and liquid, a four-way valve 16 for switching between heating operation and cooling operation, and the like are provided. There is. Further, the indoor unit 20 is provided with an indoor heat exchanger 21 for exchanging heat between indoor air and a refrigerant, a blower fan 21F, and the like. The refrigerant pipe 30 connects the outdoor heat exchanger 11, the compressor 12, the oil separator 13, the expansion valve 14, the accumulator 15, the four-way valve 16, and the indoor heat exchanger 21. The refrigerant pipe 30 includes a liquid-side refrigerant pipe 30L and a gas-side refrigerant pipe 30G.

As shown in FIG. 13, the outdoor unit 10 is divided into a heat exchanger room 10A and a machine room 10B in the left-right direction by a partition plate 171, and the heat exchanger room 10A has the above-mentioned outdoor heat. The exchanger 11 and the blower fan 11F are arranged. The above-mentioned compressor 12, oil separator 13, expansion valve 14, accumulator 15, four-way valve 16 and the like are housed in the machine room 10B, and these are service panels (not shown) on the front surface of the housing 17 as shown in FIG. By removing the, it becomes visible from the outside.

Further, in the machine room 10B, an electrical component module 40 is arranged at a substantially intermediate position in the vertical direction thereof. The electrical component module 40 includes a control circuit that controls the overall operation of the air conditioner, a setting circuit for making various settings of the air conditioner, a display circuit that displays the state of the air conditioner, and an AC supplied from the outside. It is a module equipped with a converter circuit that converts electric power into DC power and outputs it, an inverter circuit that converts DC power output from the converter circuit into AC power and outputs it, and other circuits. It is equipped with multiple electronic components to realize the circuit. The printed circuit board 41 is composed of one printed circuit board 41 so as to secure a piping space on the back side of the machine room 10B.

FIG. 14 shows the front surface of the electrical component module 40. The printed circuit board 41 is mounted in the machine room 10B in an upright posture. The printed circuit board 41 is vertically divided into a light electric region 41A and a high electric region 41B.

The light electric region 41A includes electronic components such as a microcomputer that constitutes a part of the control circuit, electronic components for operating the switch 41A1 that constitutes the setting circuit, and the low power connector 41A2 for inserting and removing the plug, and a display circuit. The electronic components of the light electric system such as the LED 41A3 constituting the above are mounted. Further, in the high power region 41B, a plurality of electronic components of the high power system for performing the remaining power conversion of the control circuit, for example, a power device 41B1 such as an IC of a converter circuit and an IC of an inverter circuit, and a large capacity for smoothing. Parts such as an electrolytic capacitor 41B2 and a high power connector 41B3 are mounted.

A cooler 50 for cooling the heat generated by the power device 41B1 is further arranged in the high electric power region 41B. The cooler 50 includes a heat sink (not shown) having a shape that can be attached to the liquid side refrigerant pipe 30L of the refrigerant pipe 30. The heat sink is arranged on the front side of the printed circuit board 41, which is thermally coupled so as to transfer the heat generated by the power device 41B1, toward the service panel side (not shown). During the cooling operation, the refrigerant condensed by the outdoor heat exchanger 11 flows through the liquid-side refrigerant pipe 30L, and during the heating operation, the refrigerant condensed by the indoor heat exchanger 21 and decompressed by the expansion valve 14 flows. The heat sink of the cooler 50 is cooled by the refrigerant, and the temperature of the power device 41B1 is kept below a predetermined value. The air conditioner described above is described in Patent Document 1.

Japanese Patent No. 5472364

By the way, the power device 41B1 and the electronic components around it generate noise. Since the cooler 50 is close to the printed circuit board 41, the generated noise can easily get on. Since the cooler 50 is fixed to the refrigerant pipe 30L and the refrigerant pipe 30L is connected to the housing 17 which is the ground, the cooler 50 is also connected to the housing 17 via the refrigerant pipe 30L. Therefore, the noise is diffused to the entire housing 17, and even if measures are taken to comply with the EMC standard, the noise propagates to the outside of the housing 17, which makes the measures difficult.

Therefore, if the cooler 50 and the housing 17 are directly connected by a ground wire, the impedance between the cooler 50 and the housing 17 is lowered, and noise diffused from the cooler 50 to the entire housing 17 is generated. It can be suppressed.

However, in this method, it is necessary to specially connect the ground wire to the cooler 50, and it is necessary to newly attach the ground wire to the cooler 50, which causes a problem of poor workability.

An object of the present invention is to provide an outdoor unit of an air conditioner capable of preventing the diffusion of noise through the cooler without connecting a ground wire between the cooler and the housing.

In order to achieve the above object, the invention according to claim 1 is an outdoor unit of an air conditioner in which a housing is divided into a blower room and a machine room by a partition plate. It has an electrical component module to be connected and a cooler fixed to the refrigerant pipe in a state of being thermally coupled to the refrigerant pipe of the machine room, and the electrical component module is equipped with electronic components including a power device. The printed substrate, the conductive fixing plate on which the printed substrate is mounted, the conductive upper frame for fixing the upper part of the fixing plate to the partition plate, and the lower part of the fixing plate to be fixed to the partition plate. The cooler is mounted so as to straddle the upper frame and the lower frame, is mechanically fixed and electrically connected, and is thermally coupled to the power device. The ground wire is connected to the lower frame.

According to the present invention, since the cooler is connected to the ground wire of the switchboard via the ground wire of the upper frame, the lower frame, the fixing plate, and the lower frame, the cooler is connected to the housing by a special ground wire. Even without it, noise diffusion via the cooler can be prevented.

It is a perspective view of the outdoor unit of the Example of this invention. It is a perspective view of the outdoor unit with the service panel removed. It is a perspective view of the outdoor unit of the same outdoor unit with the electrical component module removed from the machine room. It is a developed perspective view of an electrical component module and a cooler. It is an installation explanatory view which attaches an upper frame and a lower frame to a partition plate. It is a vertical sectional view of an electrical component module. It is a cross-sectional view of the line AA of FIG. It is a top view which removed the top panel of an outdoor unit. It is the right side view which removed the right side panel of an outdoor unit. It is a front view of the main board. It is a front view of a power board. It is a circuit diagram of the refrigerant circuit of an air conditioner. It is a front view which removed the service panel of the conventional outdoor unit. It is a front view of the conventional electrical component module.

1 to 3, 8 and 9 show the outdoor unit 100 according to the embodiment of the present invention. The housing 110 of the outdoor unit 100 is made of steel plate, and has a front panel 111, a service panel 112 on the right side of the front panel 111, a right side panel 113, a left side panel 114, a top panel 115, a back panel 116, and a bottom surface. A panel 117 is provided, and a stand 118 is attached to the bottom panel 117. The housing 110 is partitioned in the left-right direction by the same steel plate partition plate 119 so that the back side of the front panel 111 becomes the heat exchanger room 110A and the back side of the service panel 112 becomes the machine room 110B. The partition plate 119 constitutes a part of the wall surface of the machine room 110B. The outdoor heat exchanger 11 and the blower fan 11F described above are arranged in the heat exchanger room 110A. Further, the above-mentioned refrigerant pipe 30, compressor 12, expansion valve 14, accumulator 15, sub-accumulator 15A, four-way valve 16 and the like are housed in the machine room 110B. The machine room 110B can be visually recognized from the front side of the outdoor unit 100 by removing the service panel 112.

Reference numeral 200 denotes an electrical component module. As shown in FIGS. 4 to 9, a steel plate fixing plate 210 arranged in the machine room 110B so that the front surface faces the back surface of the service panel 112, and an upper portion of the fixing plate 210. The long steel plate upper frame 220 to which the upper frame 220 is attached, the long steel plate lower frame 230 to which the lower part of the fixing plate 210 is attached, and the steel plate mounting bracket 240 to attach the upper frame 220 to the partition plate 119. It also has a steel plate mounting bracket 250 for attaching the lower frame 230 to the partition plate 119, and a main board 260 and a power board 270 as printed circuit boards. Electronic components and other electronic components that form part of the control circuit are mounted on the main board 260. The power board 270 is mounted with electronic components and other electronic components constituting the remaining part of the control circuit, and the power device 274 described later.

In this way, the printed circuit board of the electrical component module 200 is divided into a main board 260 and a power board 270, and the main board 260 has a fixing plate 210 such that the back surface 260b described later faces the front surface 211a described later. The power board 270 is mounted on the fixing plate 210 so that the back surface 270b described later faces the back surface 211b described later on the fixing plate 210.

Reference numeral 300 denotes a cooler, to which a U-shaped bent portion 31 of the refrigerant pipe 30 L is attached as described later, and straddles the upper frame 220 and the lower frame 230 in a state of being thermally coupled to the U-shaped bent portion 31. As such, it is attached to the upper frame 220 and the lower frame 230.

The fixing plate 210 is a main body 211 on which the main board 260 is mounted on the front 211a and the power board 270 is mounted on the back 211b, and the fixing plate 210 is for reinforcement and is bent 90 degrees from the upper end of the main body 211 toward the back 211b. It includes an upper horizontal piece 212 and an upper vertical piece 213 for mounting that is bent 90 degrees upward from the rear end of the bent piece 212. Further, a reinforcing lower horizontal piece 214 bent 90 degrees from the lower end of the main body 211 toward the front surface 211a, and a lower vertical piece 215 bent 90 degrees downward from the front end of the lower horizontal piece 214. Be prepared. Mounting portions 215a projecting downward are formed at both ends of the lower vertical piece 215.

The upper frame 220 includes a vertical piece 221 screwed to the upper vertical piece 213 of the fixing plate 210, a reinforcing upper horizontal piece 222 bent 90 degrees rearward from the upper end of the vertical piece 221 and a vertical piece 211. It is provided with a mounting piece 223 bent at 45 degrees from the left end of the screw to the front. 224 is the end to which the cooler 300 is attached.

The lower frame 230 includes a lower vertical piece 231 screwed to the lower vertical piece 215 of the fixing plate 210, an upper horizontal piece 232 bent 90 degrees rearward from the upper end of the lower vertical piece 231 and an upper horizontal piece 232. It includes an upper vertical piece 233 for reinforcement that is bent 90 degrees upward from the back end, and a mounting piece 234 that is bent 45 degrees from the left end of the lower vertical piece 231 toward the front. A terminal plate 400 is attached to the front side of the lower vertical piece 231 and the other end of the ground wire 500 to which one end is connected to a switchboard (not shown) is connected. Reference numeral 235 is an end to which the cooler 300 is attached.

The cooler 300 includes an aluminum heat sink 310 that is thermally coupled to a power device 274 mounted on the front surface 270a of the power substrate 270 and described later, and two heat sinks 310 having a semicircular cross section. It is composed of a U-shaped bent portion 31 of a liquid-side refrigerant pipe 30L fitted in the groove 311 and a steel plate cover 320 for fixing the U-shaped bent portion 31 to the heat sink 310. In addition to the groove 311 the heat sink 310 has a thick plate portion 312 to which the power device 274 is pressed and thermally coupled, and cover mounting portions 313 and 314 formed on both sides of the thick plate portion 312. The cover 320 has a central pressing portion 321 for pressing the U-shaped bent portion 31 of the liquid side refrigerant pipe 30L, a hook portion 322 bent from one end of the pressing portion 321 and a hook portion from the other end of the pressing portion 321. It is provided with a mounting portion 323 that is bent so as to face 322.

As described above, electronic components and other electronic components that form a part of the control circuit are mounted on the front surface 260a of the main board 260. That is, as shown in FIG. 10, an LED lamp 261a as a display, a display setting circuit 261 including a dip switch 261b and a button switch 261c as an operation unit, and a control IC 262 of a microcomputer or the like constituting a part of the control circuit are used. Drives a plurality of connectors 263 arranged in the peripheral portion, an EMC (ElectroMagnetic Compatibillity) filter circuit 264 for countermeasures against external noise and spontaneous noise including a capacitor 264a and a common mode choke coil 264b, and an expansion valve 14 and a four-way valve 16. An actuator drive circuit 265, a temperature detection circuit 266 connected to a thermistor (not shown) for detecting the temperature of the pipe 30, and the like are mounted. 260b is the back surface of the main board 260. 260c is the upper end, 260d is the lower end, 260e is the left end, and 260f is the right end. The main board 260 is mounted on the front surface 211a so that the back surface 260b faces the front surface 211a of the main body portion 211 of the fixing plate 210.

On the front surface 270a of the power board 270, electronic components including the power device 274 described later, which constitutes the remaining part of the control circuit as described above, are mounted. That is, as shown in FIG. 11, a diode bridge 271a for rectification, an IGBT (Insulated Gate Bipolar Transistor) element 271b in which a MOSFET is incorporated in the gate portion of a bipolar transistor to reduce operating resistance, and an FRD (Fast Recovery Diode) for high-speed operation. An element 271c, a PFC (Power Factor Correction) coil 271d for improving the force factor, and an electrolytic capacitor 271e for smoothing are mounted. These diode bridge 271a, IGBT element 271b, FRD element 271c, PFC coil 271d, electrolytic capacitor 271e and the like constitute a converter circuit 271 that converts AC power supplied from the outside into DC power and outputs it. Further, an IPM (Intelligent Power Module) element 272 that incorporates a drive circuit and a self-protection function and constitutes an inverter circuit that converts DC power supplied from the converter circuit 271 into AC power and outputs the power is also mounted. Further, elements such as a switching transformer 273a and a switching IC 273b constituting the switching power supply circuit 273 are also mounted. Reference numeral 270b is the back surface of the power substrate 270. 270c is the upper end, 270d is the lower end, 270e is the left end, and 270f is the right end. The diode bridge 271a, the IGBT element 271b, the FRD element 271c, the IPM element 272, and the like are power devices 274 that generate a large amount of heat, and are mounted vertically in the vicinity of the left end 270e. The power substrate 270 is mounted on the back surface 211b so that the back surface 270b faces the back surface 211b of the main body 211 of the fixing plate 210. The cooler 300 is brought into contact with the power device 274. Note that noise sources (not shown) other than the power device 274 and the switching power supply circuit 273, which are noise sources, are also collectively mounted on the power board 270.

In order to arrange the electrical component module 200 in the machine room 110B of the outdoor unit 100, first, a mounting bracket 240 having a slope 241 and a mounting bracket 250 having a slope 251 are attached to the partition plate 119 in advance. Then, as shown in FIG. 5, the mounting piece 223 of the upper frame 220 is screwed to the slope 241 of the mounting bracket 240, and the mounting piece 234 of the lower frame 230 is screwed to the slope 251 of the mounting bracket 250. As a result, the upper frame 220 and the lower frame 230 are attached to the partition plate 119 in a cantilevered posture in a sideways posture.

Next, as shown in FIG. 6, the heat sink 310 of the cooler 300 is screwed B1 so as to straddle between the end 224 of the vertical piece 221 of the upper frame 220 and the end 235 of the upper vertical piece 233 of the lower frame 230. , B2 to attach. Further, as shown in FIG. 7, after pressing the U-shaped bent portion 31 of the refrigerant pipe 30L against the groove 311 of the heat sink 310, the hook portion 322 of the cover 320 is engaged with one cover mounting portion 313 of the heat sink 310. Then, the pressing portion 323 is pressed against the other cover mounting portion 314 of the heat sink 310, and the pressing portion 323 is fixed to the cover mounting portion 314 with screws B3 and B4. This work is performed with the back panel 116 of the outdoor unit 100 removed. As described above, the cooler 300 is attached so as to straddle between the end portion 224 of the upper frame 220 and the end portion 235 of the lower frame 230, and so that the thick plate portion 312 of the heat sink 310 faces the service panel 112. ..

Further, the main board 260 is mounted on the front 211a of the main body 211 of the fixing plate 210, and the power board 260 is mounted on the back 211b. Then, the fixing plate 210 on which the main board 260 and the power board 270 are mounted is fitted with the upper vertical piece 213 on the vertical piece 221 of the upper frame 220 and the lower vertical piece 215 on the lower vertical piece 231 of the lower frame 230. As shown, it is attached by screws B5 and B6. At this time, the power device 274 of the power substrate 270 is pressed against the thick plate portion 312 of the heat sink 310 of the cooler 300 so as to be thermally coupled there. Therefore, when the operation of the air conditioner is started, the heat generated in the power device 274 is cooled by the cooler 300. If a heat-dissipating grease having high thermal conductivity is applied to the thick plate portion 312 of the heat sink 310, the thermal coupling becomes better. After the electrical component module 200 is attached to the machine room 110B as described above, the plug to which the required wiring is connected is connected to the connector 263 of the main board 260 of the electrical component module 200, and the terminal board 400 is required. Another wire is connected. Further, one end of the ground wire 500 is connected to the lower frame 230 by a screw B7, and the other end is connected to the ground terminal of a switchboard (not shown).

As described above, in this embodiment, the lower frame 230 of the electrical component module 200 is connected to the ground terminal of the switchboard by the ground wire 500. The heat sink 310 is made of aluminum, and the cover 320, the fixing plate 210, the upper frame 220, and the lower frame 230 are made of steel plate, all of which have conductivity. Therefore, the cooler 300 is grounded from the ground wire 500 to the ground terminal of the switchboard via the fixing plate 210, the upper frame 220, the lower frame 230, and the like. Therefore, it is possible to surely prevent the noise generated in the electrical component module 200 from being diffused to the surroundings on the cooler 300, and it is not necessary to directly connect the ground wire to the cooler 300. The ground wire 500 is a ground wire conventionally used for grounding the electrical component module.

Further, since the main board 260 and the power board 270 are mounted on the fixing plate 210 with the fixing plate 210 attached to the machine room 110B interposed therebetween, the size of the main board 260 and the power board 270 in the vertical direction can be adjusted. Compared to the vertical size of the printed circuit board when the main board 260 and the power board 270 are arranged one above the other, the size can be significantly reduced, and even for outdoor units with a housing that has little room in the vertical space. It can be applied effectively.

Further, the power device 274 mounted on the power board 270 is thermally coupled to the cooler 300 on the back surface 211b side of the fixing plate 210, but is only pressed against the cooler 300, so that it is screwed. If B5 and B6 are loosened, the fixing plate 210, the main board 260, and the power board 270 can be integrated and removed from the front of the machine room 110B without being disturbed by the cooler 300, and the main board 260 and the main board 260 can be removed. Maintenance of the power board 270 becomes easy.

Further, since the main board 260 is equipped with a display setting circuit 261 including an LED lamp 261a, a DIP switch 261b, a button switch 261c, and a plurality of connectors 263 on the front surface 260a, the outdoor unit 100 to the service panel 112 Just by removing, you can check the operation contents of the air conditioner by the display contents of the LED lamp 261a, change the setting contents by operating the DIP switch 261b, the button switch 261c, etc., or plug the plug to the connector 263. It becomes easy to switch the circuit connection by inserting and removing.

30L: Liquid side refrigerant piping, 31: U-shaped bent part 100: Outdoor unit, 110: Housing, 110A: Heat exchanger room, 110B: Machine room, 111: Front panel, 112: Service panel, 113: Right side Panel, 114: Left side panel, 115: Top panel, 116: Back panel, 117: Bottom panel, 118: Stand, 119: Partition plate 200: Electrical component module 210: Fixed plate, 211: Main body, 211a: Front , 211b: Back surface, 212: Upper horizontal piece, 213: Upper vertical piece, 214: Lower horizontal piece, 215: Lower vertical piece 220: Upper frame, 221: Vertical piece, 222: Horizontal piece, 223: Mounting piece, 224: End 230: Lower frame, 231: Lower vertical piece, 232: Upper horizontal piece, 233: Upper vertical piece, 234: Mounting piece, 235: End 240: Mounting bracket, 241: Slope 250: Mounting bracket, 251: Slope 260: Main board, 260a: Front, 260b: Back side 270: Power board, 270a: Front side, 270b: Back side, 274: Power device 300: Cooler, 310: Heat sink, 320: Cover 400: Terminal board 500: Ground wire

Claims (1)

In the outdoor unit of an air conditioner whose housing is divided into a blower room and a machine room by a partition plate
It has an electrical component module arranged in the machine room and having an earth wire connected to a switch panel, and a cooler fixed to the refrigerant pipe in a state of being thermally coupled to the refrigerant pipe of the machine room.
The electrical component module includes a printed circuit board on which electronic components including power devices are mounted, a conductive fixing plate on which the printed circuit board is mounted, and a conductive fixing plate on which an upper portion of the fixing plate is fixed to the partition plate. A frame and a conductive lower frame for fixing the lower part of the fixing plate to the partition plate are provided.
The cooler is mounted so as to straddle the upper frame and the lower frame, is mechanically fixed and electrically connected, and is thermally coupled to the power device.
An outdoor unit of an air conditioner, wherein the ground wire is connected to the lower frame.

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