JP2003004283A - Air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable miniaturization of a drive circuit and its fine controlling. SOLUTION: A dc motor is applied to an outdoor blower 8 in an outdoor unit 14 and a dc power supply circuit 24 is used as a power supply of both a drive circuit 26 of this motor and a drive circuit 25 of a compressor motor 2. Also, a refrigerant selector valve 5 is driven by dc voltage generated at a dc power supply circuit 12. These drive circuit 26 and refrigerant selector valve 5 are controlled by an outdoor control circuit 11. The dc voltage outputted from the dc power supply circuit 12 becomes power-supply voltage of the outdoor control circuit 11, and is supplied as power-supply voltage to an indoor unit 13 through a connecting cable 19. Hereby, an indoor blower 7 in the indoor unit 13 is dc-driven. Since a dc voltage value can be equalized to an ac actual value, circuitries of the drive circuits 26, 27 can be downsized and rotating speed of the blower 7, 8 can be controlled continuously. Furthermore, communication is established through the connecting cable 19 between the indoor unit 13 and the outdoor unit 14.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an indoor / outdoor separation type air conditioner.

[0002]

2. Description of the Related Art FIG. 17 shows, for example, Japanese Patent Laid-Open No. 57-5534.
FIG. 1 is a block diagram showing an example of a conventional air conditioner disclosed in Japanese Patent Publication No. 1 or the like, in which 1 is a compressor, 2 is an electric motor,
3 is an indoor heat exchanger, 4 is an outdoor heat exchanger, 5 is a refrigerant switching valve, 6 is a pressure reducer, 7 is an indoor blower, 8 is an outdoor blower, and 9 is a blower.
Is a commercial power supply, 10 is an indoor control circuit, 11 is an outdoor control circuit, 12 is a DC power supply circuit, 17 is a modulation / demodulation circuit, 19-
Reference numerals a and 19-b are connection lines.

In the figure, a compressor 1 driven by an electric motor 2, an indoor heat exchanger 3, an outdoor heat exchanger 4, a refrigerant switching valve 5 and a pressure reducer 6 constitute a refrigeration cycle.

The outdoor unit 14 receives the commercial power supply 9 and supplies it to the DC power supply circuit 12. The DC power supply circuit 12 creates a low-voltage DC power supply, and supplies the DC power supply to the indoor control circuit 10 of the indoor unit 13 through the connection line 19. Indoor control circuit 10
Controls the operation of the compressor 1 and the indoor air blower 7 based on the room temperature and the set temperature. The outdoor control circuit 11 controls the outdoor unit 14 according to a command from the indoor control circuit 10. Communication between the indoor control circuit 10 and the outdoor control circuit 11 is performed by the modulation / demodulation circuit 1 connected to the connection line 19.
This is performed by superposing a signal modulated at high frequency on the DC power source of the connection line 19 via 7.

According to this conventional technique, there is a feature that the connecting line between the indoor unit 13 and the outdoor unit 14 is only the connecting line 19.

In the prior art, the outdoor unit receives the commercial AC power supply voltage from the commercial power supply. However, as described in, for example, Japanese Patent Laid-Open No. 56-155326, the indoor unit receives the commercial AC power supply voltage. It is also known that power is received and sent to the outdoor unit, converted into a DC voltage by the outdoor unit and sent to the indoor unit.

[0007]

The above-mentioned prior art only discloses that commercial alternating current is converted into direct current by the outdoor unit and sent to the indoor unit, and no consideration is given to further multifunctionalization of the air conditioner. .

An object of the present invention is to solve such a problem and to make the air conditioner multifunctional.

[0009]

To achieve the above object, the present invention provides a compressor, a refrigerant switching valve, an outdoor heat exchanger, a first pressure reducer, an outdoor blower, and a direct current power source for converting alternating current to direct current. An outdoor unit housing a circuit, an indoor unit housing a first indoor heat exchanger, a second indoor heat exchanger, a second decompressor and an indoor blower, and a DC power supply circuit and an indoor unit are connected. Then
The indoor unit includes a connection line for transmitting direct current and a drive circuit provided in the indoor unit and connected to the connection line for driving the indoor blower.

Further, according to the present invention, an indoor control circuit is provided in the indoor unit and an outdoor control circuit is provided in the outdoor unit, and communication between the indoor control circuit and the outdoor control circuit is performed via a connection line. .

Power is supplied to the indoor unit by direct current as described above, but the peak value of direct current can be smaller than that of alternating current. Therefore, the insulation distance of the substrate pattern and the like can be reduced, and the risk of ignition is low, so that the wind speed switching drive circuit and the like can be downsized.
Due to the effects of these miniaturization, a space for the indoor unit can be provided, and by disposing a dehumidification valve there, cycle reheat dehumidification operation becomes possible.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of an air conditioner according to the present invention. 3a and 3b are indoor heat exchangers, 9'is a commercial power source, 14-a and 14-b are oscillator circuits, and 18 and 19 are shown. Is a connection line, 24 is a DC power supply circuit, 25-
Reference numeral 27 is a drive circuit, and 28 is a two-way valve. The parts corresponding to those in FIG.

In the figure, two connection lines 18 and 19 are provided between the indoor unit 13 and the outdoor unit 14,
One of the connection lines 18 is connected from the indoor commercial power supply 9 to the DC power supply circuits 12 and 24 of the outdoor unit 14 via the indoor unit 13. Therefore, the commercial AC voltage from the commercial power supply 9 is supplied to the outdoor unit 14 through the connection line 18, and is converted into the DC voltage by the DC power supply circuits 12 and 24. Also,
The connection line 19 is connected between the DC power supply circuit 12 in the outdoor unit 14 and an electrical product such as the indoor control circuit 10 in the indoor unit 13, and the DC voltage generated in the DC power supply circuit 12 causes the indoor control circuit 10 or the like. It becomes the power supply voltage of the electrical products.

As a result, the indoor unit can be directly connected to the outlet for the room air conditioner provided in the room to take in the commercial AC voltage, and the outdoor unit is wired as in the prior art shown in FIG. No longer needed.

The power supply voltage of the indoor blower 7 and the indoor control circuit 10 in the indoor unit 13 is the DC voltage supplied from the DC power supply circuit 12 of the outdoor unit 14 through the connection line 19. In consideration of the required maximum voltage of these electric components, the voltage can be set to a low voltage of about 35V. When such a low DC voltage is used as the power supply voltage, the indoor unit 13
No large parts for high voltage are required for the electric appliances and there is no possibility of heat generation and ignition, so that it is completely unnecessary to cover the wind speed switching drive circuit of the indoor blower 7 with an iron plate or the like. As for the power supply to the indoor unit 13, since the peak value of the DC voltage can be smaller than that of the AC voltage, the insulation distance of the substrate pattern and the like can be shortened, and the risk of ignition is small. A circuit or the like can be formed in a small size. In the case of AC voltage, the peak value is twice the square root of the effective value, but in the case of DC, the peak value and the effective value are equal. Generally, there is no risk of ignition at an AC voltage of 30 V or less, whereas there is no risk of ignition at a DC voltage of 42 V or less.

If the wind speed switching drive circuit and the like can be miniaturized,
Therefore, the indoor unit 13 can have a sufficient space, and the parts and the device can be added to further increase the functionality of the air conditioner.
For example, as a device to be added, a deodorizing device, a valve, or the like can be considered. When adding a two-way valve, for example, the indoor heat exchanger is divided into two indoor heat exchangers 3a and 3b, and these two It has a function of connecting through the valve 28 and operating one of these indoor heat exchangers 3a and 3b as a reheater and the other as a cooler as necessary to send warm dehumidified air into the room. Can be made.

In this case, the two-way valve 28 is opened in the ON state,
Although it is closed in the off state, at this time, it is not a completely closed state but serves as a pressure reducer. On,
The logic of turning off can be set depending on the system.
When the pressure reducer is in the state, the indoor heat exchanger 3a is a cooler,
The indoor heat exchanger 3b operates as a reheater, dehumidifying is performed by this cooler, and a so-called cycle reheat dehumidifying operation in which the temperature drop due to this dehumidification is compensated by the air warmed by the reheater becomes possible.

As a dehumidifying control method, the dehumidifying operation is performed by controlling the reheat amount by controlling the rotational speeds of the compressor 1, the indoor blower 7, and the outdoor blower 8. The method of controlling the number of revolutions of the blowers 7, 87 and the compressor 1 includes the method described below.

That is, the drive circuit 26 for supplying the drive current to the outdoor blower 8 is about 220V supplied from the DC power supply circuit 24 composed of a PWM control inverter circuit.
PWM control is performed on the DC voltage to generate a DC voltage for driving the motor in the range of 0V to about 220V according to a command from the outdoor control circuit 11. As a result, the rotation speed of the outdoor blower 8 is finely controlled according to the command from the outdoor control circuit 11.

As described above, by applying the DC motor to the outdoor blower 8, fine control of the outdoor blower 8 can be performed, the control range is expanded, and the dehumidification amount can be easily controlled.

On the other hand, when an induction motor is applied to the outdoor blower 8, it cannot be directly started at a low speed because of the relationship with the starting torque. For this reason, it is necessary to once switch to high speed operation and then to low speed operation, and since the limit of low speed operation is higher than that of the DC motor, the control range becomes narrow. Further, in some cases, a low speed operation below this range is required, but this is not possible, so a method is required to perform an intermittent operation to obtain an effect equivalent to that when such a low speed operation is performed. .
Further, in order to switch the rotation speed of the induction motor, a method of providing a tap on the way and switching this is required.

Therefore, for example, when it is desired to increase the reheat amount, it is necessary to reduce the rotation speed of the outdoor blower.
When the induction motor is applied, as shown in FIG. 2 (a), first, the motor is temporarily started at a high speed operation at a startable rotation speed, and then switched to a tap for a required rotation speed, and a desired low speed operation is started. Need to let. Moreover, since the number of rotation speed switching stages is determined by the number of taps, it is not suitable for performing fine control for determining the reheat amount. Further, when the operation below the limit of the low speed operation is required, as shown in FIG. 2 (a), intermittent operation is performed so that the average rotation speed becomes equal to the required rotation speed of the low speed operation. The required amount of reheat can be obtained, but during such an intermittent operation, a change in the refrigerant noise during the intermittent operation, an intermittent noise of the blower, etc. occur, which is not preferable.

When the DC motor is applied, since there is no problem such as starting torque, as shown in FIG. 2 (b), it is possible to directly start up at low speed operation, and simply change the applied voltage. Since the rotation speed can be changed, even if you want to increase the reheat amount, you can set the low-speed operation of the rotation speed corresponding to this by controlling the applied voltage, and you can change the rotation speed continuously. It can be changed, and fine control for determining the reheat amount is possible. Therefore,
All of the above problems when applying an induction motor are solved,
It is very effective.

A DC motor is used as the indoor blower 7, and the indoor control circuit 10 controls it. The drive circuit 27 for supplying a drive current to the indoor blower 7 includes a switching circuit and an inverter circuit,
About 35 supplied via the connection line 19 from the outdoor unit 14
The DC power supply voltage of V is stepped down by the switching circuit, and this is controlled by the inverter circuit to 0 to about 35 V according to the load such as the outside air temperature, the room temperature, and the set temperature, and the indoor blower 7 Supply to the DC motor of. DC motors have a lower voltage than AC motors,
Control is possible without stopping due to insufficient torque.

The refrigerant switching valve 5 has a DC power supply circuit 12
It is driven by the DC voltage from. Electric motor 2 of compressor 1
Is driven by being supplied with a DC voltage from a DC power supply circuit 24 via a drive circuit 25. This drive circuit 25 is controlled by the outdoor control circuit 11 and thereby the electric motor 2 is controlled. A method for controlling the electric motor 2 is described in Japanese Patent Publication No. 58-25038.

The connection line 19 is also used for communication of information between the indoor control circuit 10 and the outdoor control circuit 11.
Therefore, in the indoor unit 13, the oscillation circuit 14 is connected to the connection line 19.
A modulation / demodulation circuit 17-a to which the output signal of −a is supplied is connected, and the modulation / demodulation circuit 17-a and the indoor control circuit 1 are connected.
Information signals are exchanged with 0. Outdoor unit 1
Similarly, in No. 4, the modulation / demodulation circuit 17-b to which the output signal of the oscillation circuit 14-b is supplied is connected to the connection line 19, and the information signal is exchanged between the modulation / demodulation circuit 17-b and the outdoor control circuit 11. Is performed.

The information signal output from the indoor control circuit 10 modulates the carrier wave output from the oscillator circuit 14-a by the modulation / demodulation circuit 17-a, and the modulated carrier wave is superimposed on the DC voltage on the connection line 19. And is transmitted to the outdoor unit 14. In the outdoor unit 14, this information signal is demodulated by the demodulation circuit 17-b.
Is demodulated by and is supplied to the outdoor control circuit 11. The information signal output from the outdoor control circuit 11 modulates the carrier wave output from the oscillation circuit 14-b by the modulation / demodulation circuit 17-b, and the modulated carrier wave is superimposed on the DC voltage on the connection line 19. Transmitted to the indoor unit 13
Then, this information signal is demodulated by the demodulation circuit 17-a and supplied to the indoor control circuit 10.

Here, the information signal transmitted from the indoor control circuit 10 to the outdoor control circuit 11 is control information for controlling the outdoor unit 14 as in the conventional air conditioner, and the outdoor control circuit 11 is provided. The information signals supplied from the indoor control circuit 10 to the indoor control circuit 10 include response information to the control information from the indoor unit 13 and information indicating the state of each part of the outdoor unit 14.
As described above, in this embodiment, the commercial AC voltage is received from the indoor unit 13 side by the same number of control lines as the above-described conventional air conditioner, and the commercial AC voltage or DC between the indoor unit 13 and the outdoor unit 14 is received. It is possible to perform voltage transmission and information communication between the indoor control circuit 10 and the outdoor control circuit 11.

FIG. 3 shows the modulation / demodulation circuits 17-a, 17 shown in FIG.
FIG. 19 is a circuit diagram specifically showing the connection relationship of −b to the connection line 19, wherein 19-a and 19-b are electric wires, 21-a and 21-.
Reference numeral b denotes a capacitor, and 22-a and 22-b denote inductors. Parts corresponding to those in FIG.

In the figure, the connecting wire 19 is two electric wires 1.
9-a and 19-b, and one electric wire 19-b thereof is grounded. The modulation / demodulation circuit 17-a of the indoor unit 13 is connected to the transmission terminal and the reception terminal of the indoor control circuit 10, and the wire 19- that is not grounded via the DC blocking capacitor 21-a. connected to a. Further, the electric wire 19-a is connected to the capacitor 21-a.
An inductor 22-a for blocking a transmission signal is provided between a connection point between the electric wire 19-a and the indoor control circuit 10. Similarly, the modulation / demodulation circuit 17-b on the outdoor unit 14 side
Is connected to the transmission terminal and the reception terminal of the outdoor control circuit 11, and the DC blocking capacitor 21-
It is connected via b to the electric wire 19-a which is not grounded. Further, the electric wire 19-a has a capacitor 21
An inductor 22-b for blocking a transmission signal is provided between the DC power supply circuit 12 and a connection point between -b and the electric wire 19-a.

Next, the operation of this specific example will be described with reference to FIG. 4 showing the signals of the respective parts of FIG.

As described above, the DC voltage generated in the DC power supply circuit 12 is supplied to the indoor unit 13 as the power supply voltage for the indoor control circuit 10 and the indoor blower 7 via the electric wires 19-a and 19-b. . At this time, the capacitor 21-b prevents the DC voltage from being supplied to the modulation / demodulation circuit 17-b, and the capacitor 21-a prevents the DC voltage from being supplied to the modulation / demodulation circuit 17-a. It Therefore, this DC voltage is supplied to the indoor control circuit 10, the indoor blower 7, etc. as a power supply voltage.

Now, when a transmission information signal as shown in FIG. 4A is generated from the transmission terminal of the indoor control circuit 10, this transmission information signal is supplied to the modulation / demodulation circuit 17-a, and the transmission information signal shown in FIG.
The carrier wave from the oscillation circuit 14-a as shown in (b) is modulated. This carrier wave is a signal having a frequency sufficiently higher than that of the transmission information signal. The modulated signal obtained by this is supplied to the electric wire 19-a via the capacitor 21-a and is superimposed on the DC voltage from the DC power supply circuit 12. As a result, the transmission information signal is supplied to the outdoor unit 14 via the electric wire 19-a.

The transmission information signal from the modulation / demodulation circuit 17-a is sent to the indoor control circuit 10 by the inductor 22-a.
And the indoor blower 7 and the like are blocked, and only the DC voltage is supplied to the indoor control circuit 10, the indoor blower 7, and the like.

Here, the electric wire 19 is connected from the modulation / demodulation circuit 17-a.
The amplitude value of the transmission information signal supplied to −a is set to be smaller than the voltage value of the DC voltage on the connection line 19, and as a result, as shown in FIG. Never be interrupted by. Therefore, sufficient power is supplied to the indoor control circuit 10 and the indoor blower 7.

In the outdoor unit 14, the transmission information signal transmitted through the electric wire 19-a is separated from the DC voltage by the capacitor 21-b and extracted, and the modulation / demodulation circuit 17 is provided.
-B is supplied for demodulation, demodulated into a reception information signal as shown in FIG. 4D, and supplied to the outdoor control circuit 11 from the reception terminal.

As described above, the information signal is communicated from the indoor unit 13 to the outdoor unit 14.

The communication from the outdoor unit 14 to the indoor unit 13 is similar, and the carrier wave from the oscillation circuit 14-b as shown in FIG. 4B is transmitted / received to the transmission terminal of the outdoor control circuit 11 by the modulation / demodulation circuit 17-b. 4A is modulated by a transmission information signal output from the indoor unit 1 and is superimposed on the DC voltage via the capacitor 21-b as shown in FIG.
3 is transmitted. In the indoor unit 13, only this transmission signal is extracted by the capacitor 21-a, demodulated by the modulation / demodulation circuit 17-a as shown in FIG. 4 (d), and supplied to the indoor control circuit 10 from the reception terminal.

In this way, with one connection line 19, the supply of the DC power supply voltage from the DC power supply circuit 12 to the indoor unit 13 and the information communication between the indoor control circuit 10 and the outdoor control circuit 11 are performed. It will be possible.

FIG. 5 shows the modulation / demodulation circuit 17-a shown in FIG.
FIG. 17 is a circuit diagram showing a specific example of a modulator and oscillator circuits 14-a and 14-b in 17-b. Here, the modulation / demodulation circuit 17
Since the modulation unit of −a and the modulation unit of the modulation / demodulation circuit 17-b and the oscillation circuit 14-a and the oscillation circuit 14-b have the same configuration, the modulation / demodulation circuit 17-a and the oscillation circuit 14-a will be described.

In the figure, an oscillating circuit 14-including resistors R16 to R20, a capacitor C05 and a voltage comparator COM2.
a is configured. The output signal of the oscillation circuit 14-a is amplified by the transistors Q3 and Q4 so as to have the above-mentioned amplitude, and is supplied to the electric wire 19-a via the capacitor 21-a. Normally, the input terminal 15-a is set to a high level, the transistor Q2 turns on, and the capacitor C0
5 is short-circuited. As a result, the oscillation circuit 14-a is stopped. The transmission information signal is input as a low level signal from the input terminal 15-a to turn off the transistor Q2. As a result, the oscillator circuit 14-a generates a carrier wave. That is, since the carrier wave is generated during the low level transmission information signal, the transmission signal modulated by the transmission information signal is obtained from the transistor Q4.

FIG. 6 shows a modulation / demodulation circuit 17-a, shown in FIG.
It is a circuit diagram which shows a specific example of the demodulation part in 17-b. Here, since the demodulation units of the modulation / demodulation circuit 17-a and the modulation / demodulation circuit 17-b have the same configuration, the modulation / demodulation circuit 17-a
The demodulation unit will be described.

In the figure, the transmission information signal extracted by the capacitor 21-a is supplied to the voltage comparator COM1.
It is compared with the reference voltage determined by the resistors R05 and R06. When the transmission information signal obtained by modulating the carrier wave is not sent, the input voltage of the voltage comparator COM1 is lower than the reference voltage, and the output voltage of the voltage comparator COM1 is zero. On the other hand, when the transmission information signal is sent, since the amplitude of the carrier wave is higher than the reference voltage, the voltage comparator CO
A signal having the frequency of this carrier is output from M1. This output signal of the voltage comparator COM1 is rectified and smoothed by the diode D and the capacitor C03 to drive the transistor Q1. As a result, the reception information signal is obtained from the output terminal 16-a. This reception information signal is supplied to the reception terminal of the indoor control circuit 10 in FIG.

As described above, in this embodiment, since the DC voltage is not interrupted by the transmission signal, the electric power from the outdoor unit 14 can be used effectively in the indoor unit 13, and the outdoor unit can be used effectively. The DC power supply circuit 12 provided in 14 can be downsized, and since the electric power supplied to the indoor unit 13 does not decrease, it is possible to prevent a decrease in the air volume of the indoor blower 7.

In the above embodiment, the commercial power supply voltage is received by the indoor unit 13, but it can also be directly received by the outdoor unit 14. In this case, the outdoor unit 14
Alternatively, when a plurality of indoor units 13 are connected, the commercial power supply voltage connection line 18 becomes unnecessary, and only the connection line 19 for transmitting the DC voltage supplies the power supply voltage to the indoor unit 13 and the indoor control circuit 10 and the outdoor control circuit. Communication between 11 is possible, and the number of connecting lines is only 2.

As described above, the indoor / outdoor separation type air conditioner in which the outdoor unit 14 receives the commercial power supply voltage is characterized in that only two connecting lines are required between the outdoor unit and the indoor unit.

FIG. 7 is a block diagram showing another embodiment of the air conditioner according to the present invention, in which reference numeral 15 is a solar cell, parts corresponding to those in FIG. To do.

In this embodiment, a solar cell is connected to the outdoor unit 14 in the embodiment shown in FIG.

In FIG. 7, the outdoor unit 14 is provided with a connection terminal for a solar cell, and when the solar cell 15 is connected thereto, the solar cell 15 and the DC power supply circuit 24 are connected to drive circuits 25, 26. And the output DC voltage of the solar cell 15 is supplied to the DC power supply circuit 12. In this case, it goes without saying that the output voltage of the solar cell 15 is used when the amount of sunlight is large and the output voltage value of the solar cell 15 is large. For this reason, although not shown, the outdoor unit 1
There is provided a means for preventing backflow of current from 4 to the solar cell 15.

In this embodiment, of course, a DC power supply other than a solar cell can be used, but the electric components of the outdoor unit 14 and the indoor unit 13 such as the blowers 7 and 8 and the refrigerant switching valve 5 are converted to DC. Therefore, another DC power source such as the solar cell 15 can be used without converting its output voltage to AC.

FIG. 8 is a block diagram showing still another embodiment of the air conditioner according to the present invention. The parts corresponding to those of FIG. 1 are designated by the same reference numerals and the duplicated description will be omitted.

In the figure, in the indoor unit 13, the connection line 1
9 is connected between the indoor control circuit 10 and the indoor control circuit 10, and in the outdoor unit 14, the connection line 19 and the outdoor control circuit 1 are connected.
A modulation / demodulation circuit 17-b is connected between the first and second terminals. The transmission information signal output from the indoor controller 10 modulates the DC voltage on the connection line 19 by the modulation / demodulation circuit 17-a and is transmitted to the outdoor unit 14, and in the outdoor unit 14, this transmission information signal is demodulated. It is demodulated in 17-b and supplied to the outdoor control circuit 11. The transmission information signal output from the outdoor control circuit 11 is connected to the connection line 19 by the modulation / demodulation circuit 17-b.
The above DC voltage is modulated and transmitted to the indoor unit 13, and in the indoor unit 13, this transmission information signal is demodulated by the modulation / demodulation circuit 17-a and supplied to the indoor control circuit 10.

The structure other than the above structure is omitted in the drawings, but is the same as the embodiment shown in FIGS. 1 and 7.

As described above, in this embodiment, the transmission information signal modulates the DC voltage, whereby the information signal is communicated between the indoor control circuit 10 and the outdoor control circuit 11, and in this embodiment as well. A commercial AC voltage is received from the indoor unit 13 side by the same number of control lines as the above-described conventional air conditioner, and transmission of the commercial AC voltage or DC voltage between the indoor unit 13 and the outdoor unit 14 and an indoor control circuit. 10, information communication between the outdoor control circuit 11 can be performed.

FIG. 9 shows the modulation / demodulation circuits 17-a and 17 in FIG.
FIG. 19 is a circuit diagram showing a specific example of −b,
-B is an electric wire, 20-a and 20-b are transformers, 21-
a, 21-b are capacitors, 22-a, 22-b are inductors, 23-a1, 23-a2, 23-a3, 23-
Reference numerals b1, 23-b2, and 23-b3 denote windings, and portions corresponding to those in FIG.

In the figure, the modulation / demodulation circuit 1 of the indoor unit 13
7-a is a transformer 20-a, a DC blocking capacitor 21-a, and an impedance increasing inductor 22-.
It consists of a and. The connection line 19 between the indoor control circuit 10 and the DC power supply circuit 12 is composed of two electric wires 19-a and 19-b, and one terminal of the winding wire 23-a1 of the transformer 20-a is directly connected to the electric wire 19-b. , The other terminal is cabasita 2
The electric wires 19-a are respectively connected via 1-a. The winding 23-a2 of the transformer 20-a is connected to the transmission terminal of the indoor control circuit 10 and the winding 23-a3 of the transformer 20-a is used.
Are connected to the receiving terminals of the indoor control circuit 10, respectively.
Further, the electric wire 19-a is provided with an inductor 22-a between the connection point between the capacitor 21-a and the electric wire 19-a and the indoor control circuit 10.

Similarly, the modulation / demodulation circuit 1 on the outdoor unit 14 side
7-b is a transformer 20-b, a DC blocking capacitor 21-b, and an impedance increasing inductor 22-.
It consists of b and. Winding 23-in transformer 20-b
One terminal of b1 is directly connected to the electric wire 19-b, and the other terminal thereof is connected to the electric wire 19-a via the capacitor 21-b. The winding 23-b2 of the transformer 20-b is connected to the transmission terminal of the outdoor control circuit 11, and the winding 23-b3 of the transformer 20-b is connected to the reception terminal of the outdoor control circuit 11. Further, the electric wire 19-a has a capacitor 2
An inductor 22-b is provided between the connection point between 1-b and the electric wire 19-a and the DC power supply circuit 12.

Next, the operation of this specific example will be described with reference to FIG. 10 showing the signals of the respective parts in FIG.

As described above, the DC voltage generated in the DC power supply circuit 12 is supplied to the indoor control circuit 10 via the electric wires 19-a and 19-b. At this time, the capacitor 21-
b prevents this DC voltage from being supplied to the transformer 20-b, and capacitor 21-a prevents this DC voltage from being supplied to the transformer 20-a. Therefore, this DC voltage is supplied to the indoor control circuit 10 and the like as a power supply voltage.

Now, when a transmission information signal having positive and negative levels as shown in FIG. 10A is output from the transmission terminal of the indoor control circuit 10, this transmission information signal is transmitted to the transformer 20-.
a through the windings 23-a2 and 23-a1 of the electric wire 19-
a, 19-b, and as shown in FIG.
The DC voltage is modulated and transmitted to the transformer 20-b. At this time, the impedance increasing action of the inductor 22-a prevents the transmission information signal from being transmitted to the indoor control circuit 10. In the transformer 20-b, only the transmission information signal is extracted from the DC voltage modulated by the transmission information signal by the capacitor 21-b (FIG. 10 (c)), and the windings 23-b1, 23-b3 of the transformer 20-b are extracted. The signal is received by the reception terminal of the outdoor control circuit 11 via. At this time, due to the impedance increasing action of the inductor 22-b,
The transmission information signal is prevented from being transmitted to the DC power supply circuit 12.

Similarly, the transmission information signal output from the transmission terminal of the outdoor control circuit 11 includes the windings 23-b2, 23-b1, the electric wires 19-a, 19-b of the transformer 20-b.
It is sent to the receiving terminal of the indoor control circuit 10 via the windings 23-a1, 23-a3 of the transformer 20-a. Also in this case, the inductors 22-a and 22-b prevent the transmission information signal from being supplied to the indoor control circuit 10 and the DC power supply circuit 12.

In this manner, the DC power supply circuit 12 to the indoor control circuit 1 of the indoor unit 13 are connected by the single connecting line 19.
It is possible to supply a DC power supply voltage to 0 and the like and to perform information communication between the indoor control circuit 10 and the outdoor control circuit 11.

FIG. 11 is a block diagram showing still another embodiment of the air conditioner according to the present invention, in which reference numeral 20 is a display circuit, and portions corresponding to those in FIG. Omit it.

In the figure, the connection line 19 and the modulation / demodulation circuit 1
During communication between the indoor control circuit 10 and the outdoor control circuit 11 via 7-a and 17-b, if the received signal is interrupted for a specified time (time varies depending on the communication content etc.), a communication error occurs. The indoor control circuit 10 and the outdoor control circuit 11 judge that this is an abnormality of the communication circuit and the indoor unit 13 and the outdoor unit 1
4, that is, the operation of the air conditioner is stopped, and the indoor control circuit 10 drives the display device 20 to display the failure. As such a failure display, for example, a display device provided in the indoor unit 13 of the air conditioner so as to be seen from the room is used as a display device, and a display method other than the normal display (for example, blinking) is used. Just do it.

As a result, it is possible to easily know the communication abnormality, and it is possible to promptly take measures such as repair.

FIG. 12 is a block diagram showing still another embodiment of the air conditioner according to the present invention, in which 21 is a cutoff circuit, and the portions corresponding to those in FIG. Omit it.

In the figure, a cutoff circuit 21 for cutting off the DC voltage from the DC power supply circuit 12 is provided on the outdoor unit 14 side. The shutoff circuit 21 is controlled by the outdoor control circuit 11, and when the outdoor control circuit 11 determines an abnormality in the communication circuit, the air conditioner is stopped and the shutoff circuit 2
1 is driven to cut off the supply of the DC voltage to the indoor unit 13.

According to this, it is possible to electrically protect against the failure of the indoor unit 13.

The breaker circuit 21 can be constituted by a relay or a semiconductor switch connected in series with the connection line.

FIG. 13 is a block diagram showing still another embodiment of the air conditioner according to the present invention, in which 22 is a diode, the parts corresponding to those in FIG. To do.

In the figure, the connection line 1 is connected to the indoor unit 13.
A diode 22 is connected between 9-a and 19-b. Here, the diode 22 is connected to the connection line 19-b whose anode is grounded and to the connection line 19-a whose cathode is not grounded, respectively. Therefore, the connection line 19
-A is the + side of the DC voltage, and connection line 19-b is the-of the DC voltage.
If the connection line 19 is properly connected so as to be on the side,
Reverse voltage is applied to the diode 22 to turn it off,
The DC voltage is normally supplied from the DC power supply circuit 12 to the indoor unit 13.

However, by mistake, the connecting line 19-a is on the anode side of the diode 22, and the connecting line 19-b is the diode 22.
Assuming that the connection line 19 is connected to the indoor unit 13 so as to be on the cathode side, a forward voltage is applied to the diode 22 in the forward direction to turn on the diode 22. Therefore, an overcurrent flows in the DC power supply circuit 12, the overcurrent protection circuit in the DC power supply circuit 12 operates, and the supply of the DC voltage is stopped. As a result, the indoor control circuit 10 is protected against overcurrent.

If the DC power supply circuit 12 is not provided with an overcurrent protection circuit, as shown in FIG. 14, a current fuse 23 is provided on at least one of the connection lines 19-a and 19-b and the connection is made. When an overcurrent flows due to an erroneous connection of the wire 19, the current fuse 23 is blown and the supply of the DC voltage to the indoor unit 13 is cut off. As a result, the indoor control circuit 10 is protected against overcurrent.

In the embodiment shown in FIGS. 13 and 14,
Further, the DC power supply voltage is not reduced or lost by the diode 22 and the current fuse 23, the capacity of the DC power supply circuit 12 can be reduced, and the temperature rise of the indoor control circuit 10 can be suppressed.

FIG. 15 is a block diagram showing the embodiment described above more concretely. 101 is a power switch, 102 is an indoor control microcomputer, 103 is a thermistor circuit, 104 is a wireless remote controller, and 105 is a wireless receiving circuit. , 106 is a buzzer circuit, 107 is a vertical wind direction plate motor, 108 is a reset circuit, 109 is an indoor control circuit, 110 is an indoor blower drive circuit, 201 is an electromagnetic contactor, 202 is a power supply circuit, 203 is a power module, 2
Reference numeral 04 is an outdoor control microcomputer, 205 is a position detection circuit, 20
6 beat circuit, 207 is a power supply control circuit, 208 is a switching valve drive circuit, 209 is an outdoor blower drive circuit, 210 is a thermistor circuit, 211 is a display circuit, and 212 is a reset circuit. The same reference numerals are attached.

In the figure, a commercial AC voltage is received by the indoor unit 13, and the connection line 18 is passed through the power switch 101.
The outdoor unit 14 is supplied with power. The power switch 101 is a switch for the entire air conditioner, and is turned off when the air conditioner is not used for a long time.

The indoor control circuit 10 is mainly composed of the indoor control microcomputer 102. Indoor control microcomputer 1
Reference numeral 02 captures room temperature data detected by the thermistor circuit 103. The user sets the set temperature, operation mode, wind speed, etc. by the wireless remote controller 104, and the setting signal from the wireless remote controller 104 is received by the wireless receiving circuit 105 and supplied to the indoor control microcomputer 102. The indoor control microcomputer 102 is the thermistor circuit 1
An on / off signal of the compressor 1 (FIG. 8), a rotation speed command signal, and the like corresponding to the difference between the room temperature detected in 03 and the set temperature are calculated and created.

The buzzer circuit 106 generates a confirmation sound when it receives a signal from the wireless remote controller 104. The display circuit 20 normally displays the operating state of the air conditioner, and is composed of an operating lamp, a dehumidifying lamp, and the like. A vertical wind direction plate motor 107 is provided to move a vertical wind direction plate (not shown) that changes the direction of the wind blown from the air conditioner. Further, the reset circuit 108 is used for the indoor control microcomputer 102 when the power is turned on.
The reset signal is supplied to.

The commercial AC voltage supplied to the outdoor unit 14 via the connection line 18 is converted into a direct current by the DC power supply circuit 12 on the one hand to the switching valve 5, and on the other hand, the electromagnetic contactor 20.
1 and the drive circuit 2 of the outdoor blower 8 via the power supply circuit 202
6 and the power module 203. The electromagnetic contactor 201 is turned on when the compressor 1 is in operation, and is turned off during stoppage to shut off the power supply. The power supply circuit 202 rectifies and smoothes the commercial AC voltage to form a high-voltage DC voltage.
The power module 203 has six switching elements connected in a bridge, and switches this DC voltage to supply it to the electric motor 2 for driving the compressor.

The outdoor control circuit 11 is mainly composed of the outdoor control microcomputer 204. Outdoor microcomputer 204
Is to drive the electric motor 2. Here, a DC brushless motor is used as the electric motor 2. The DC brushless motor is characterized by high efficiency and excellent controllability, but it is necessary to detect the magnetic pole position of the rotor. The magnetic pole position of this rotor is the position detection circuit 2
05, the outdoor control microcomputer 204 performs arithmetic processing, and a signal for switching the power module 203 is formed. The drive circuit 206 amplifies the signal output from the outdoor control microcomputer 204 and drives the power module 203. In addition, the current limiting circuit 20
Reference numeral 7 detects a current flowing through the power supply circuit 202, the power module 203 and the like to control the current flowing through the electric motor 2 and protects the power module 203 from an excessive current.

The switching valve 5 and the outdoor blower 8 are operated by the switching valve drive circuit 208, in accordance with the command from the outdoor control microcomputer 204.
It is driven by the outdoor blower drive circuit 209.

The thermistor circuit 210 detects the temperature of the outdoor heat exchanger 4, the outside air temperature, the temperature of the compressor 1 and the like. Based on the detection results, the outdoor control microcomputer 204 causes the compressor 1 to operate via the control circuit 206. Rotation speed control etc. are performed.

The display circuit 221 displays an operating state, a cause of stop when a trip occurs, or a failure display when a communication error occurs.

The reset circuit 212 is the outdoor control microcomputer 2
04 reset control is performed.

The commercial AC voltage is supplied to the DC power supply circuit 12 of the outdoor unit 14. This DC power supply circuit 12 is an indoor unit 13
A DC voltage is formed as a power supply voltage to be supplied to. The power supply voltage used in the outdoor control circuit 11 may be created by the DC power supply circuit 12 or may be created by providing another power supply circuit.

The DC voltage generated by the DC power supply circuit 12 is supplied to the indoor unit 13 via the connection line 19. The indoor control circuit power supply 109 forms the power supply voltage used in the indoor control circuit 10 by the DC voltage supplied from the outdoor unit 14.

The indoor blower drive circuit 110 includes the outdoor unit 14
The DC voltage supplied from the generator forms a voltage for driving the indoor blower 7. A DC brushless motor is used as the indoor blower 7, and the air volume of the indoor blower 7 can be controlled by controlling the drive voltage according to a command from the indoor control microcomputer 102. When an excessive current flows through the indoor blower 7, the indoor blower drive circuit 110 sends a signal to the indoor control microcomputer 102, which causes the indoor control microcomputer 102 to stop the indoor blower 7.

Communication between the indoor control microcomputer 102 and the outdoor control microcomputer 204 is performed by the modulation / demodulation circuits 17-a, 17-.
b and connecting line 19. Modulation / demodulation circuit 17-
a is connected to the connection line 19, and the indoor control microcomputer 1
By modulating the DC voltage of the connection line 19 with a high frequency in accordance with the transmission signal output from 02, the transmission signal is superimposed on this DC voltage. The modulation / demodulation circuit 17-b has a connection line 19
The high-frequency signal is detected from the DC voltage of and is supplied to the outdoor control microcomputer 204. The same applies when communicating from the outdoor control microcomputer 204 to the indoor control microcomputer 102.

In this communication method, two-way communication cannot be performed at the same time, so communication is performed alternately. The contents of communication include an ON / OFF signal of the compressor 1, a rotation speed signal, an instruction of the outdoor blower 8 and the like. In addition, the information on the outside air temperature and the trip factor of the outdoor unit 14 is also communicated.

The communication is performed by dividing the above data into a predetermined unit (8 bits in this embodiment). A start bit and a stop bit are added to each 8-bit data, and the entire reader section is provided. Communication is continuously and alternately performed, but if communication is stopped or the above bits cannot be read correctly, it is determined that communication is abnormal.

The outdoor control circuit 11 has the initiative in communication, and the outdoor control circuit 11 determines the communication abnormality. There are two types of communication abnormalities: there is no response from the indoor control circuit 10 even if communication is performed from the outdoor control circuit 11 to the indoor control circuit 10, and erroneous data is received from the indoor control circuit 10. . In the former case, Fig. 1
As shown in FIG. 6 (a), when there is no response from the indoor control circuit 10 for a predetermined time, it is determined that the communication is abnormal, and in the latter case, as shown in FIG. If the data is incorrect, it is determined that communication is abnormal. Whether or not there is an error in the data can be determined by the start bit, the stop bit, whether the reader section has a regular waveform, whether the parities match, and the like. In this case, if the data error time continues for a predetermined time or more, or if the data error count is a predetermined count or more, it is determined that the data is incorrect.

In any case, when the communication failure continues for a predetermined time or a predetermined number of times, it is determined that the communication is abnormal.

[0093]

As described above, according to the present invention,
Since the indoor unit is operated with a low DC power supply voltage, large components for high voltage are not required in the drive circuit of the indoor blower, and there is no danger of heat generation and ignition. Is unnecessary, and indoor electric parts can be downsized. In addition, since the solenoid valve coil of the refrigerant switching valve of the outdoor unit and the outdoor blower are operated with a DC voltage, it can be used without converting the DC power supply such as solar power generation to AC, and since it uses a brushless motor for the blower, it is highly efficient. Efficiency can be improved. Needless to say, if the blower of the outdoor unit is driven by a low-voltage DC power supply, the same effect as the indoor unit can be obtained.

Further, according to the present invention, the DC voltage is supplied from the outdoor unit to the indoor unit and the connection between the indoor unit and the outdoor unit is increased without increasing the number of connecting lines between the indoor unit and the outdoor unit. Can communicate.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of an air conditioner according to the present invention.

FIG. 2 is a diagram showing a difference in rotational speed control between an induction motor and a DC motor.

3 is a block diagram showing in more detail the connection relationship with the connection lines of the modulation / demodulation circuit in FIG.

FIG. 4 is a waveform diagram showing signals of respective parts in FIG.

5 is a circuit diagram showing a specific example of a modulator and an oscillator circuit of the modulation / demodulation circuit in FIG.

6 is a circuit diagram showing a specific example of a demodulation unit of the modulation / demodulation circuit in FIG.

FIG. 7 is a block diagram showing another embodiment of the air conditioner according to the present invention.

FIG. 8 is a block diagram showing still another embodiment of the air conditioner according to the present invention.

9 is a circuit diagram showing a specific example of a modulation / demodulation circuit in FIG.

FIG. 10 is a waveform diagram showing signals of respective parts in FIG.

FIG. 11 is a block diagram showing still another embodiment of the air conditioner according to the present invention.

FIG. 12 is a block diagram showing still another embodiment of the air conditioner according to the present invention.

FIG. 13 is a block diagram showing still another embodiment of the air conditioner according to the present invention.

FIG. 14 is a block diagram showing still another embodiment of the air conditioner according to the present invention.

FIG. 15 is a block diagram more specifically showing the embodiment shown in FIGS. 8 and 11 to 14;

FIG. 16 is a flowchart showing a specific example of a communication abnormality determination method.

FIG. 17 is a block diagram showing an example of a conventional air conditioner.

[Explanation of symbols]

1 compressor 2 electric motor 3a, 3b Indoor heat exchanger 4 outdoor heat exchanger 5 Refrigerant switching valve 6 pressure reducer 7 Indoor blower 8 outdoor blowers 9,9 'Commercial power supply 10 Indoor control circuit 11 Outdoor control circuit 12 DC power supply circuit 13 Indoor unit 14 outdoor unit 14-a, 14-b oscillator circuit 15 solar cells 17-a, 17-b modulation / demodulation circuit 18, 19 connection line 20 Display circuit 21 Breaking circuit 22 diode 23 Current fuse 24 DC power supply circuit 25 Compressor motor drive circuit 26 Outdoor blower drive circuit 27 Indoor blower drive circuit 28 two-way valve

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Koji Kato             800 Tomita, Ohira-cho, Shimotsuga-gun, Tochigi             Hitachi, Ltd. Living Equipment Division (72) Inventor Shiro Kurashima             800 Tomita, Ohira-cho, Shimotsuga-gun, Tochigi             Hitachi, Ltd. Living Equipment Division (72) Inventor Hiroyuki Shono             800 Tomita, Ohira-cho, Shimotsuga-gun, Tochigi             Hitachi, Ltd. Living Equipment Division F-term (reference) 3L061 BA04

Claims (2)

[Claims] 1. A compressor, a refrigerant switching valve, an outdoor heat exchanger, a first pressure reducer, a first indoor heat exchanger acting as a reheater during dehumidifying operation, and a cooler during dehumidifying operation. A second indoor heat exchanger that functions as a decompressor, and a second decompressor that is provided between the first indoor heat exchanger and the second indoor heat exchanger and that functions as a decompressor during dehumidification operation, An air conditioner including an outdoor blower and an indoor blower, the compressor, the refrigerant switching valve, the outdoor heat exchanger, the first pressure reducer, the outdoor blower, and a direct current for converting alternating current to direct current. An outdoor unit accommodating a power supply circuit, the first indoor heat exchanger, the second indoor heat exchanger, the second
An indoor unit accommodating the decompressor and the indoor blower, a connection line for connecting between the DC power supply circuit and the indoor unit, and transmitting DC to the indoor unit, and the connection provided in the indoor unit. An air conditioner connected to a wire and having a drive circuit for driving the indoor blower. 2. The indoor control circuit according to claim 1, wherein the indoor control circuit is provided in the outdoor unit, and the outdoor control circuit is provided in the outdoor unit, and the communication between the indoor control circuit and the outdoor control circuit is performed through the connection line. An air conditioner characterized by being carried out through.