JP2005257266A - Refrigerating apparatus and inverter device used therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the reliability of refrigerating cycle while miniaturizing a refrigerating apparatus and an inverter device, and to perform high-level control or failure diagnosis of the refrigerating apparatus. <P>SOLUTION: This refrigerating apparatus comprises a first substrate 220 mounted with a converter 22a and an inverter 221a and a radiation fin 263 closely fitted to the opposite side thereof, a second substrate 230 mounted with a microcomputer 231, a current detecting mechanism 234 and a terminal block 260, and a third substrate 240 mounted with an interface connector 242 and a photocoupler 243. Each substrate is arranged in layers, and a signal of discharge gas temperature of a compressor 101 is inputted to the microcomputer 231 through the interface connector 242. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a refrigeration apparatus equipped with a compressor motor having a variable rotation speed, and an inverter apparatus used therefor.

  Conventionally, in order to facilitate specification change without changing the inverter basic section, a first board on which an AC voltage from an AC power source is converted to DC and an inverter which is a DC / AC converter, Microcomputer for managing an inverter basic unit comprising a second board on which a controller including a microcomputer for controlling is mounted, a third board on which a terminal block, an inrush suppression resistor and a smoothing capacitor are mounted, and an inverter control device It is known that the processing is separated into an I / O block unit that manages an input / output interface, which is described in Patent Document 1, for example.

Japanese Patent Laid-Open No. 11-41943

  In the above-described prior art, the degree of freedom for changing the specifications has increased, but since it is not particularly considered to be used for the refrigeration cycle, problems specific to the refrigeration cycle, for example, the compressor has a large current, The electric expansion valve to be adjusted, the signals of various temperature or pressure detection sensors, etc. are small currents, large and small signals are mixed and easily affected by unnecessary radiated electromagnetic noise, and downsizing of the refrigeration unit itself is also required. , Etc. are not fully considered.

  An object of the present invention is to improve the reliability of a refrigeration cycle while reducing the size of a refrigeration device and an inverter device with downsizing of refrigeration devices such as air conditioners and refrigerators, particularly outdoor units. It is to make it more suitable for advanced control and fault diagnosis.

  In order to achieve the above object, the present invention includes a refrigeration cycle including a compressor, and the compressor is an refrigeration apparatus driven by an electric motor whose operating frequency is variably controlled. A first substrate on which a power semiconductor that constitutes a converter for converting DC into an inverter and an inverter that is a DC / AC converter is mounted, and a radiating fin is in close contact with the opposite surface of the mounting surface, and a microcomputer that controls the power semiconductor A second board on which a current detection mechanism for detecting the current of the motor, a terminal block of the motor is mounted, and signals of various temperature or pressure detection sensors of the refrigeration cycle are input. And a third board on which a photocoupler that transmits an input signal to the microcomputer by an optical signal is mounted, and 1 board, 2nd board, and 3rd board | substrate are arrange | positioned hierarchically, and the signal of the discharge gas temperature of the said compressor is input into the said microcomputer via the said interface connector. .

  Moreover, in the above, it is desirable to output the frequency of the inverter through the interface connector.

  Furthermore, in an inverter device that variably controls the operating frequency of an electric motor that drives a compressor of a refrigeration cycle, a power semiconductor that constitutes a converter that converts AC voltage from an AC power source into DC and an inverter that is a DC / AC converter is mounted. A first board having a radiation fin in close contact with the opposite surface of the mounting surface, a microcomputer for controlling the power semiconductor, a current detection mechanism for detecting a current of the motor, and a terminal block of the motor. A mounted second substrate, an interface connector to which signals of various temperature or pressure detection sensors of the refrigeration cycle are input, and a photocoupler that transmits the input signals to the microcomputer by optical signals. A third board mounted, and arranged in a hierarchy in the order of the first board, the second board, and the third board. , In which the signal of the discharge gas temperature of the compressor through a connector wherein the interface is input to the microcomputer.

  Furthermore, in the above, it is desirable to output the frequency of the inverter through the interface connector.

  According to the present invention, the board on which the power semiconductor and the microcomputer are mounted is surrounded by the shielded box-shaped case, and the board on which the interface connector is mounted is hierarchically compact so that the board is at the top. Because the signal of the sensor for detecting various temperatures or pressures of the refrigeration cycle is transmitted from the interface connector to the microcomputer by an optical signal, unnecessary radiated electromagnetic noise is suppressed and the cause of noise generation is reduced. Cycle reliability can be improved.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a system diagram of a refrigeration cycle according to one embodiment, in which a compressor 101, an indoor heat exchanger 102, an indoor expansion valve 104, an outdoor heat exchanger 105, and an accumulator 107 are sequentially connected to supply refrigerant. It is circulated to form a refrigeration cycle. When the room is cooled, the refrigerant compressed by the compressor 101 is condensed and liquefied by the outdoor heat exchanger 105, then decompressed by the indoor expansion valve 104, evaporated by the indoor heat exchanger 102, and compressed by the compressor 101. Return to. The indoor fan motor 103 promotes heat exchange of the indoor unit 109, and the outdoor fan motor 106 promotes heat exchange of the outdoor unit 108.

The compressor 101 is driven by an electric motor 111 whose operation frequency is variably controlled in relation to the capacity required for the refrigeration cycle, and the operation frequency is controlled by an inverter device 210.
The refrigeration cycle includes the opening of an indoor expansion valve 104 or an outdoor expansion valve (not shown) for adjusting the refrigerant flow rate in addition to the rotation speed of the compressor 101, the rotation speed of the indoor fan motor 103 and the outdoor fan motor 106, A four-way valve (not shown) for switching the operation mode of cooling / heating is controlled. As information for this, an operation command signal from the remote controller for setting the operation mode, temperature, etc., the temperature of each part (the discharge gas temperature of the compressor, the suction) Temperature, heat exchanger temperature, etc.) and a signal for detecting the pressure are input to the control device. In addition, operation data of the refrigeration apparatus or the air conditioner (for example, suction pressure, discharge pressure, compressor upper temperature, outdoor unit expansion valve such as temperature and pressure of main parts in the refrigeration cycle) via the interface connector 242 Opening, indoor unit expansion valve opening, compressor current value, compressor frequency, outside air temperature, evaporation temperature, suction temperature, blowing temperature, freezing temperature, required frequency, gas pipe temperature, set temperature, etc.) are input or output. The

  FIG. 2 is a circuit diagram of an inverter device, in which a power semiconductor that constitutes a converter that converts AC voltage from an AC power source 250 to DC and an inverter that is a DC / AC converter is mounted, and aluminum is mounted on the opposite side of the mounting surface. A first substrate (metal substrate) 220 to which a heat-radiating fin made of metal is closely attached, a microcomputer (microcomputer) 231, a current detection mechanism 234 for detecting a current of the motor 111, and a terminal block 261 of the motor 111 are mounted. Second board (control board) 230, an inrush suppression resistor 244 for suppressing an inrush current to the motor 111, and an interface connector 242 to which signals of various temperature or pressure detection sensors of the refrigeration cycle are input. And a photocoupler 243 that transmits the input signal to the microcomputer 231 by an optical signal. It consists of. The smoothing capacitor 251 is externally attached to the first substrate 220.

  The AC voltage from the AC power supply 250 is converted into a direct current by a converter 222a (a plurality of rectifying elements 222 are bridge-connected), and an inverter 221a (a power conversion means in which the switching elements 221 are three-phase bridge-connected) is a DC / AC converter. The microcomputer 231 controls the AC frequency to drive the electric motor 111.

  In the converter 222a, the AC voltage is rectified by the plurality of rectifying elements 222, and reaches the smoothing capacitor 251 via the magnet switch 253 that operates or stops the compressor 101 and the power factor reactor 252. In the inverter 221 a, a flywheel element 223 is provided along with the switching element 221 in order to regenerate the counter electromotive force generated from the electric motor 111 generated at the time of switching by the switching element 221, and both are mounted on the first substrate 220.

  A driver circuit 232 that amplifies a weak signal from the microcomputer 231 to a level at which the switching element 221 can be driven is provided between the microcomputer 231 and the switching element 221. The current supplied to the electric motor 111 is detected by the current detection mechanism 234, and the signal is taken into the microcomputer 231 and monitored. A part of the direct current generated by the converter 222a in the first substrate 220 is adjusted to about 5V from the high voltage used in the inverter 221a by the power supply circuit 233 provided in the second substrate 230, and the microcomputer 231, The driver circuit 232 and the current detection mechanism 234 are supplied.

  A transmission circuit 241 is mounted on the third board (interface board) 240, an interface connector 242 to which signals of various temperature or pressure detection sensors of the refrigeration cycle are inputted, and the inputted signal to the microcomputer 231. A photocoupler 243 that transmits by an optical signal is provided. Between the cycle control board 254 and the microcomputer 231, signals from various temperature or pressure detection sensors in the refrigeration cycle indicate the opening of the indoor expansion valve 104 or the outdoor expansion valve (not shown) for adjusting the refrigerant flow rate, Rotation speed of motor 103 for blower and motor 106 for outdoor fan, control signal for four-way valve (not shown) for switching between cooling / heating operation modes, inverter current, inverter frequency, abnormality of inverter itself, normal state signal Are transmitted and received through the photocoupler 243 with electrical isolation. In particular, the operating frequency of the inverter is output via the photocoupler 243 and the interface connector 242, and the operating state of the refrigeration cycle is grasped, the cause analysis when the operation is stopped, and the failure analysis are performed. Further, an inrush suppression resistor 244 is provided on the third substrate 240 in parallel with the magnet switch 253 so that the magnet switch 253 that is closed when the power is turned on does not weld due to an excessive inrush current flowing through the electrolytic capacitor 251.

  Inverter control, that is, the microcomputer 231 required to change the operating frequency by switching at high speed is required to have a high speed, but the capacity control of the refrigeration cycle, the mode switching of the cooling and heating, etc. are slow. The microcomputer 231 can share control of various control valves of the refrigeration cycle (the outdoor expansion valve, the outdoor fan motor 106, and the four-way valve for switching between the cooling / heating operation modes). In particular, if the drive circuit for the outdoor expansion valve is provided on the first substrate 220 and a signal for detecting the discharge gas temperature of the compressor 101 is input to the microcomputer 231 via the interface connector 242, the capacity of the compressor 101 can be improved. By controlling the refrigerant flow rate so that the discharge gas superheat is optimized by the microcomputer 231, the control circuit as the entire refrigeration cycle can be simplified, wiring and the like can be reduced, and the size can be reduced.

  FIG. 3 shows how the inverter device is assembled when mounted, FIG. 4 shows a finally assembled state, and FIG. 5 shows a cross section. The side surfaces of the first substrate 220 and the second substrate 230 are covered with a resin-molded case 262 whose surface is coated or plated with a shielding metal film as a shielding process in order to suppress the generation of electromagnetic noise. . The front surface of the case 262 is provided with a stepped portion 261 that is partially cut away so that the terminal block 260 is disposed, and the heat dissipating fins 263 that dissipate the heat of the converter 222a and the inverter 221a together on the bottom mounting surface. Are closely attached.

  The case 262 may be made of metal by die-casting aluminum or the like, but if it is made of resin, a complicated shape can be obtained at a low price. Therefore, the terminal block 260 can be arranged to fit the stepped portion 261, and the terminal block 260 Does not protrude beyond the upper surface of the case 262. Therefore, a wasteful space can be eliminated even when the inverter device is mounted on, for example, an outdoor unit of an air conditioner, which is desirable from the viewpoint of suppressing electromagnetic noise. Further, the first substrate 220, the second substrate 230, and the third substrate 240 are arranged in order from the bottom surface of the case 262 and stored in the case 262. Further, the power semiconductor surface of the first substrate 220 is filled with gel up to a substantially alternate long and short dash line A in FIG. 5 to protect the power semiconductor elements (diodes and IGBTs constituting the converter 222a and the inverter 221a). Further, from the gel surface to the substantially two-dot chain line B in FIG. 5 and the upper surface of the second substrate 20, resin is sealed for protection and insulation, and the power module ISPM is collected.

  Within the side surface side of the case 262, the first lead pin 225 that connects the first substrate 220 and the second substrate 230, and the second lead that connects the first substrate 220 and the third substrate 240 similarly. The second substrate 230 and the third substrate 240 are connected by the third lead pin 235 provided on the second substrate 230. The third substrate is supported by a substrate support spacer 236 provided on the second substrate.

  As described above, the assembly man-hours can be reduced and the component mounting area can be reduced, and the converter 222a, the inverter 221a and the microcomputer 231 on which the power semiconductor is mounted, and the current detection for detecting the current of the electric motor 111 are performed. Since the mechanism 234 is surrounded by the box-shaped case 262 and the heat radiating fins that are shielded to suppress the generation of electromagnetic noise, unnecessary radiated electromagnetic noise can be suppressed.

  In addition, the converter 222a and the inverter 221a are mounted on the same board (first board 220), the microcomputer 231 that controls the power semiconductor, the current detection mechanism 234 that detects the current of the motor 111, and the terminal block 260 of the motor. Since the second board on which the is mounted is compactly arranged close to the hierarchy, the wiring length of the portion where the possibility of noise generation is large can be shortened, so that the cause of noise generation can be reduced.

  Further, an interface to which signals of various temperature or pressure detection sensors of the refrigeration cycle, which are relatively weak signals having a large influence of electromagnetic noise, for example, a large influence from the compressor 101 that requires a large current, is input. Since the third board 240 on which the connector 242 is mounted is arranged at the top and is transmitted to the microcomputer 231 by an optical signal, it is possible to improve the reliability of the refrigeration cycle by eliminating malfunction due to noise mixing. Furthermore, since the power semiconductor surface of the first substrate 220 is filled with gel and further resin-encapsulated from the gel surface to the upper surface of the second substrate 230, the reliability of the power module ISPM itself is also improved.

  Furthermore, when changing the software of the microcomputer 231 or the hardware of the input / output interface according to the configuration of the refrigeration cycle, the capacity of the refrigeration apparatus or the air conditioner, the model for the store, the building mulch, etc. This can be easily handled by separating the uppermost third substrate 240. Even at this time, since the current values are arranged in descending order from the bottom surface of the case 262, the degree of freedom of handling is high, for example, the number of wires can be reduced.

The refrigeration cycle figure of the freezing apparatus by one embodiment of this invention. The block diagram of the inverter apparatus by one embodiment of this invention. The perspective view which shows the assembly method of the inverter apparatus by one embodiment of this invention. The perspective view which shows the assembled state of the inverter apparatus by one embodiment of this invention. Sectional drawing of the inverter apparatus by one embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 ... Compressor, 102 ... Indoor heat exchanger, 104 ... Indoor expansion valve, 105 ... Outdoor heat exchanger, 108 ... Outdoor unit, 109 ... Indoor unit, 111 ... Electric motor, 210 ... Inverter device, 220 ... First substrate 221 ... switching element 221a ... inverter 222 ... rectifier element 222a ... converter 224 ... second lead pin 225 ... first lead pin 230 ... second substrate 231 ... microcomputer 233 ... power supply circuit 234 ... Current detection mechanism, 235 ... third lead pin, 236 ... substrate support spacer, 240 ... third substrate, 242 ... photocoupler, 243 ... interface connector, 250 ... AC power supply, 260 ... terminal block, 261 ... step Part, 263 ... radiating fins.

Claims (4)

A refrigeration cycle having a compressor, wherein the compressor is driven by an electric motor whose operating frequency is variably controlled;
A power substrate that constitutes a converter that converts an AC voltage from an AC power source into a DC and an inverter that is a DC / AC converter is mounted, and a first substrate in which a radiation fin is in close contact with the opposite surface of the mounting surface; A second substrate on which a microcomputer for controlling a semiconductor, a current detection mechanism for detecting a current of the electric motor, a terminal block of the electric motor are mounted, and signals of sensors for detecting various temperatures or pressures of the refrigeration cycle And a third board on which an optical connector for transmitting the inputted signal to the microcomputer by an optical signal is mounted, the first board and the second board. Are arranged in a hierarchy in the order of the third substrate, and the discharge gas temperature signal of the compressor is transmitted to the microcomputer via the interface connector. Refrigeration and wherein the input to the.   2. The refrigeration apparatus according to claim 1, wherein the frequency of the inverter is output through the interface connector. In the inverter device that variably controls the operating frequency of the electric motor that drives the compressor of the refrigeration cycle,
A power substrate that constitutes a converter that converts an AC voltage from an AC power source into a DC and an inverter that is a DC / AC converter is mounted, and a first substrate in which a radiation fin is in close contact with the opposite surface of the mounting surface; A second substrate on which a microcomputer for controlling a semiconductor, a current detection mechanism for detecting a current of the electric motor, a terminal block of the electric motor are mounted, and signals of sensors for detecting various temperatures or pressures of the refrigeration cycle And a third board on which an optical connector for transmitting the inputted signal to the microcomputer by an optical signal is mounted, the first board and the second board. Are arranged in a hierarchy in the order of the third substrate, and the discharge gas temperature signal of the compressor is transmitted to the microcomputer via the interface connector. Inverter and wherein the input to the. 4. The inverter device according to claim 3, wherein the frequency of the inverter is output through the interface connector.

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