JP2007225197A - Air conditioning device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air conditioning device capable of reducing driving signal terminals and cost of components even in the case of driving and controlling a plurality of electronic expansion valves. <P>SOLUTION: The air conditioning device is equipped with the plurality of electronic expansion valves each adjusting the supply amount of a refrigerant to a plurality of heat exchangers, a plurality of motors STM1, STM2 each driving the electronic expansion valves, and a driving signal terminal group (25) for giving driving signals to the motor STM1, STM2. The air conditioning device is also equipped with switching means 22, 23 for selectively switching one out of the plurality of motors STM1, STM2 to a drivable state, and a driving/controlling means 20 for driving and controlling only the motor that the switching means 22, 23 switched out of the motors STM1, STM2 by outputting a driving signal. The plurality of motors STM1, STM2 share the driving signal terminal group (25). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an air conditioner including a plurality of electronic expansion valves that respectively adjust the amount of refrigerant supplied to a plurality of heat exchangers, and a plurality of motors that respectively drive the electronic expansion valves.

In general, for multiple buildings, multiple indoor units are arranged in parallel, and multiple outdoor units with built-in compressors, outdoor heat exchangers, etc. are connected in parallel to the inter-unit piping connected between the indoor units. Multi-type air conditioners are known.
Since this type of multi-type air conditioning apparatus includes a plurality of outdoor units, there is an advantage that a large-capacity air conditioning system can be easily configured by combining them.

By the way, when configuring an air conditioning system in which a plurality of outdoor units are combined in this way, there may be a plurality of outdoor heat exchangers built in one outdoor unit. This is because, when configuring a heat exchanger with the required capacity, it is better to configure with a plurality of heat exchangers than to configure with one large capacity heat exchanger in terms of efficiency and controllability. Because.
In these outdoor heat exchangers, for example, during heating, the liquid refrigerant from the condenser (indoor heat exchanger) is depressurized, and the flow rate of the refrigerant supplied to each outdoor heat exchanger depends on the air conditioning (heating) load. An electronic expansion valve is provided for adjustment. In principle, the electronic expansion valve has a configuration in which a needle valve is provided on the rotating shaft of the stepping motor, and the flow rate of the refrigerant can be precisely controlled.

FIG. 5 is a timing chart when the electronic expansion valve is driven and controlled by 1-2 phase excitation. Here, the electronic expansion valve includes a four-phase stepping motor, and each phase of the four-phase stepping motor is denoted by A to D.
In the four-phase stepping motor, the A-phase winding is excited in Step 1 where the operation starts, and in the next Step 2, only the A-phase winding is continuously excited.
In Step 3, the A phase winding is continuously excited and the B phase winding is newly excited. In Step 4, the A phase winding is de-energized and the B phase winding is continuously excited.
In Step 5, the B-phase winding is continuously excited and the C-phase winding is newly excited. In Step 6, the B-phase winding is de-energized and the C-phase winding is continuously excited.

In Step 7, the C-phase winding is continuously excited and the D-phase winding is newly excited. In Step 8, the C-phase winding is de-energized and the D-phase winding is continuously excited.
In step 1 of the second period, the A phase winding is excited and the D phase winding is continuously excited. In the next step 2, the A phase winding is continuously excited and the D phase winding is not turned on. In the same way, 1-phase excitation and 2-phase excitation are performed alternately until the operation ends, and the drive is controlled.

Each phase winding of the stepping motor of each electronic expansion valve is generally connected to an independent drive signal terminal for each stepping motor and is excited in each pattern as disclosed in Patent Document 1. .
JP-A-7-19629

As described above, in the conventional air conditioner, when driving and controlling a plurality of electronic expansion valves, a drive signal terminal for each phase winding is required for each electronic expansion valve. There is a problem of rising.
The present invention has been made in view of the above-described circumstances, and even when driving and controlling a plurality of electronic expansion valves, it is possible to reduce drive signal terminals and reduce component costs. An object is to provide an air conditioner.

  An air conditioner according to the present invention includes a plurality of electronic expansion valves that respectively adjust the amount of refrigerant supplied to a plurality of heat exchangers, a plurality of motors that respectively drive the electronic expansion valves, and drive signals to the motors. In an air conditioner having a drive signal terminal group for providing, a switching means for selectively switching one of the plurality of motors to a driveable state, and outputting a drive signal only to the motor switched by the switching means Drive control means for controlling the drive, and the drive signal terminal group is configured to be shared by the plurality of motors.

  In this air conditioner, the plurality of electronic expansion valves adjust the amount of refrigerant supplied to the plurality of heat exchangers, the plurality of motors drive the electronic expansion valves, respectively, and the drive signal terminal group serves as the motor. Give drive signal. The switching means selectively switches one of the plurality of motors to a driveable state, and the drive control means outputs drive signals only to the motors switched by the switching means to control driving, and a drive signal terminal group Are shared by multiple motors.

  The air conditioning apparatus according to the present invention is characterized in that the drive control means is configured to stop outputting the drive signal for a predetermined period immediately before the switching means switches.

  The air conditioner according to the present invention realizes an air conditioner that can reduce drive signal terminals and reduce component costs even when driving and controlling a plurality of electronic expansion valves. Can do.

  In addition, according to the air conditioner of the present invention, it is possible to reduce drive signal terminals even when driving and controlling a plurality of electronic expansion valves, to reduce component costs, and to provide electronic expansion valves. The regenerative voltage of the winding of the motor that drives the motor can be released, and an air conditioner in which the rotational performance of the motor is not deteriorated by regenerative energy can be realized.

Hereinafter, the present invention will be described with reference to the drawings illustrating embodiments thereof.
FIG. 1 is a piping diagram showing a refrigeration cycle of an embodiment of an air conditioner according to the present invention, and shows a refrigerant flow path during heating operation.
In this refrigeration cycle, during heating operation, the gaseous refrigerant compressed to high temperature and high pressure by the compressor 6 of the outdoor unit passes through the four-way valve 3 that is switched for heating operation, and heat exchange of the indoor unit is performed. It is sent to a condenser (condenser) 7 as a condenser. The high-temperature and high-pressure refrigerant sent to the condenser 7 is deprived of heat (condensation heat) to the indoor air by an indoor fan (not shown) and is condensed and liquefied, and the temperature of the indoor air rises.

  The liquefied refrigerant is decompressed while being sent to the outdoor unit, and the decompressed refrigerant is adjusted in flow rate according to the air conditioning (heating) load by the electronic expansion valve 1, and a part of the refrigerant whose flow rate is adjusted It is sent to the evaporator 5 which is a heat exchanger of the unit, and the flow rate of the remainder is adjusted by the electronic expansion valve 2 that bypasses the evaporator 5. The refrigerant passing through the evaporator 5 and the refrigerant whose flow rate is adjusted by the electronic expansion valve 2 are further sent to the evaporator 4.

The refrigerant sent to the evaporators 4 and 5 is evaporated (vaporized) by supplying vaporization heat to the outside air passing through the evaporators 4 and 5 by an outdoor fan (not shown), and then the compressor passes through the four-way valve 3. Return to 6. The gaseous refrigerant returned to the compressor 6 is compressed again to a high temperature and high pressure, and is sent to the condenser 7 of the indoor unit via the four-way valve 3.
During the cooling operation, the refrigerant flows in the reverse path to that during the heating operation described above, and the functions of the evaporators 4 and 5 and the condenser 7 are switched.

FIG. 2 is a block diagram showing an electrical system of the outdoor unit of the air conditioner according to the present invention.
In the outdoor unit, AC power from the AC power supply 10 is converted into DC power by the converter circuit 12, and the converted DC power is supplied to the inverter circuit 16. A compressor motor 6 a that drives the compressor 6 is connected to the output terminal of the inverter circuit 16.

A control unit 13 incorporating a microcomputer is connected between the output terminals of the converter circuit 12. Between the ground side output terminal of the converter circuit 12 and the control unit 13, an outdoor fan motor 14 with a built-in rotation speed control device, an expansion valve motor 1a of the electronic expansion valve 1, and an expansion valve motor 2a of the electronic expansion valve 2 are independent of each other. Connected.
The control unit 13 converts the output voltage of the converter circuit 12 with a built-in switching power supply circuit to use as a drive power supply.
Between the output terminals of the AC power supply 10, a switching circuit 11 and a four-way valve actuator 3a are connected in series.

The control unit 13 measures the piping temperature and the outdoor temperature based on the voltages from the thermistors 17 and 18, and expands the outdoor fan motor 14 and the electronic expansion valve 1 based on the measured temperatures and the control signal from the indoor unit. The valve motor 1a and the expansion valve motor 2a of the electronic expansion valve 2 are driven and controlled. Further, the control unit 13 drives and controls the compressor motor 6a through the inverter circuit 16, and switches the switching circuit 11 to switch the four-way valve 3 (FIG. 1).
The expansion valve motor 1a and the expansion valve motor 2a are stepping motors having four-phase windings.

FIG. 3 is a block diagram showing a connection configuration of the microcomputer, the expansion valve motor 1a (STM1), and the expansion valve motor 2a (STM2) built in the control unit 13.
The microcomputer 20 incorporated in the control unit 13 outputs drive permission signals P1 and P2 of the expansion valve motor 1a (STM1) and the expansion valve motor 2a (STM2) via the interface circuit 21 that converts the signal level. The drive permission signals P1 and P2 are given from the interface circuit 21 to the bases of the PNP transistors 22 and 23 through the resistors R1 and R3, respectively.
A DC power supply voltage + V is applied to the emitters of the transistors 22 and 23, and resistors R2 and R4 are connected between the emitters and the bases of the transistors 22 and 23, respectively.

The collector of the transistor 22 is connected to one end of each of the four-phase windings A1, B1, C1, and D1 of the expansion valve motor 1a (STM1) via a drive signal terminal of the terminal plate 25.
The collector of the transistor 23 is connected to one end of each of the four-phase windings A2, B2, C2, D2 of the expansion valve motor 2a (STM2) via a drive signal terminal of the terminal plate 25.

The microcomputer 20 outputs drive signals to the four-phase windings of the expansion valve motor 1a (STM1) and the expansion valve motor 2a (STM2) via the interface circuit 24 that converts the signal level.
The interface circuit 24 is connected to the windings A1, B1, C1, D1 of the expansion valve motor 1a (STM1) and the windings A2, B2 of the expansion valve motor 2a (STM2) via the four drive signal terminals of the terminal plate 25. , C2, D2 are connected to the other ends. That is, the other ends of the windings A1, A2 are connected to one drive signal terminal, the other ends of the windings B1, B2 are connected to one drive signal terminal, and the other ends of the windings C1, C2 are connected to one drive signal terminal. The other ends of the windings D1, D2 are connected to one drive signal terminal.

Hereinafter, an operation of driving and controlling the electronic expansion valve of the air conditioner having such a configuration will be described with reference to the timing chart of FIG.
Here, an example of operation when the expansion valve motor 1a (STM1) and the expansion valve motor 2a (STM2) are driven and controlled by 1-2 phase excitation will be described.
In step 1, which starts the operation, the microcomputer 20 turns on the drive permission signal P1 of the expansion valve motor 1a (STM1) and then energizes the winding A1. In the next step 2, the microcomputer 20 continues to turn on only the winding A1. Excited.

In Step 3, the winding A1 is continuously excited and the winding B1 is newly excited. In Step 4, the winding A1 is de-energized and the winding B1 is continuously excited.
In Step 5, the winding B1 is continuously excited and the winding C1 is newly excited. In Step 6, the winding B1 is de-energized and the winding C1 is continuously excited.
In step 7, the winding C1 is continuously excited and the winding D1 is newly excited.
Here, assuming that the opening degree control of the expansion valve motor 1a (STM1) is completed in step 7, after step 7, the output of the drive signals to all windings A1, B1, C1, D1 is stopped and de-excitation is performed. Then, during the period in which the expansion valve motor 1a (STM1) is in the regeneration mode, the drive permission signal P1 is turned on to release the regeneration voltage.

The microcomputer 20 then proceeds to drive control of the expansion valve motor 2a (STM2), turns off the drive permission signal P1, and then turns on the drive permission signal P2 of the expansion valve motor 2a (STM2) in step 1 The winding A2 is excited, and in the next step 2, only the winding A2 is continuously excited.
In Step 3, the winding A2 is continuously excited and the winding B2 is newly excited. In Step 4, the winding A2 is de-energized and the winding B2 is continuously excited.

In Step 5, the winding B2 is continuously excited and the winding C2 is newly excited. In Step 6, the winding B2 is de-energized and the winding C2 is continuously excited.
Here, assuming that the opening degree control of the expansion valve motor 2a (STM2) is completed in step 6, after the completion of step 6, the output of drive signals to all windings A2, B2, C2, D2 is stopped and de-excited. Then, during the period in which the expansion valve motor 2a (STM2) is in the regeneration mode, the drive permission signal P2 is turned on to release the regeneration voltage. Thereafter, the drive permission signal P2 is turned off, and the operation of the opening degree control is ended.

  By processing the regeneration mode of the stepping motor according to the timing chart as described above, it is possible to drive and control a plurality of electronic expansion valves using a common control terminal. Each electronic expansion valve requires a drive signal terminal for a drive permission signal, but the total number of drive signal terminals of the stepping motor can be reduced. In addition, since the electronic expansion valves are driven and controlled one by one, the power capacity can be reduced.

It is a piping system figure showing the refrigerating cycle of an embodiment of an air harmony device concerning the present invention. It is a block diagram which shows the electric system of the outdoor unit of the air conditioning apparatus which concerns on this invention. It is a block diagram which shows the connection structure of the microcomputer and expansion valve motor which a control part incorporates. It is a timing chart which shows the operation example which drives and controls the electronic expansion valve of the air conditioning apparatus which concerns on this invention. It is a timing chart which shows the operation example which drives and controls the electronic expansion valve of the conventional air conditioning apparatus.

Explanation of symbols

1, 2 Electronic expansion valve 1a, 2a Expansion valve motor (STM1, STM2)
4,5 Evaporator 6 Compressor 7 Condenser
13 Control Unit 17, 18 Thermistor 20 Microcomputer 22, 23 PNP Transistor 25 Terminal Board A1, B1, C1, D1, A2, B2, C2, D2 Winding

Claims (2)

A plurality of electronic expansion valves that respectively adjust the amount of refrigerant supplied to the plurality of heat exchangers, a plurality of motors that respectively drive the electronic expansion valves, and a drive signal terminal group that provides drive signals to the motors In the air conditioner,
A switching means for selectively switching one of the plurality of motors to a drivable state; and a drive control means for controlling the drive by outputting a drive signal only to the motor switched by the switching means. An air conditioner configured to share a signal terminal group with the plurality of motors.   The air conditioner according to claim 1, wherein the drive control means is configured to stop outputting the drive signal for a predetermined period immediately before the switching means switches.

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