JP2010243059A - Air conditioner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce standby power requirement, particularly in an exterior unit, in an air conditioner composed of an indoor unit and an outdoor unit. <P>SOLUTION: The air conditioner includes a current detector which detects the alternating current which flows through a power line linking the indoor unit and the outdoor unit, and a switch for carrying out communicating operation of a circuit when a current value detected by the current detector exceeds a predetermined reference value. The air conditioner is composed to start the operation of an outdoor control circuit via the switch and to operate the outdoor control circuit according to driving of a motor of the indoor unit. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

The present invention relates to an air conditioner that includes an indoor unit and an outdoor unit, and is configured to supply driving power for the indoor unit via a crossover line between the outdoor unit and the unit.

  As a conventional air conditioner, there is a separation type air conditioner composed of an indoor unit and an outdoor unit, and commercial AC power is supplied from the indoor unit to the outdoor unit via an AC power line between the units. After that, some outdoor units returned to DC power and then supplied again to the indoor units.

  This DC power is high voltage DC power (main power circuit output) when the air conditioner is in air conditioning operation, and low voltage DC when air conditioning operation is not performed (stopped or standby). It was electric power (output of auxiliary power circuit).

  High voltage DC power is necessary to drive the motor for the blower fan installed in the indoor unit, and low voltage DC power does not need to drive the motor when air conditioning operation is not performed. This is necessary for driving the control circuit. When the auxiliary power supply circuit is operating, the main power supply circuit (INV drive circuit, supplying power for the outdoor fan motor) is stopped, and standby power in the outdoor unit is reduced to the extent by the auxiliary power supply circuit. It was reduced.

The driving of the main power supply circuit is started when the control circuit (such as a microcomputer) of the outdoor unit receives a start signal of air conditioning operation superimposed on a DC power line that supplies DC power from the outdoor unit to the indoor unit. It was something to do. (For example, refer to Patent Document 1.)
In another conventional air conditioner, there is a separate type air conditioner composed of an indoor unit and an outdoor unit, and the indoor unit and the outdoor unit have power lines through which two commercial alternating currents flow. It is connected by a total of three lines with a signal line that shares one of these power lines. Commercial AC is directly supplied to the power line in the outdoor unit, and the outdoor unit and power line are connected to the indoor unit in order. Supplied through.

  When the air conditioning operation is stopped, the supply of AC power to the power supply circuit of the outdoor unit is interrupted by opening the relay contact. The AC power was still supplied to the indoor unit.

When the air conditioning operation is started, a voltage higher than the voltage used for transmission / reception of a normal signal is applied from the indoor unit to the signal line. The outdoor unit uses this high voltage as the starting power to excite the relay of the outdoor unit, closes the relay contact, operates the power supply circuit, and changes the outdoor unit to an operating state. (For example, see Patent Document 2.)

Japanese Patent No. 3730808 Patent 3019844

  However, in the technique described in Patent Document 1, it is necessary to maintain the microcomputer in the indoor unit and the microcomputer in the outdoor unit in a state where signals such as operation / stop can always be exchanged. That is, at least the microcomputer in the outdoor unit must always be kept in an operating state, and this standby power is always necessary. In addition, since signal lines and DC power lines are required for transmission and reception of signals, at least four lines are required together with AC power lines, resulting in erroneous wiring and troublesome installation work.

    Moreover, in the air conditioner described in Patent Document 2, a special power supply circuit is required to apply a voltage higher than the voltage used for transmission / reception of a normal signal to the signal line, and at the same time, the indoor unit and the outdoor unit It is necessary to change the communication circuit to the specifications for this high voltage. Alternatively, even if this high voltage is not increased too much, it is necessary to supply a sufficient current to excite the relay. After the start of operation of the power supply circuit due to the difference between the low impedance of the relay exciting coil and the high impedance of the communication circuit It is also necessary to have a configuration that disconnects this relay.

The present invention pays attention to the fact that the start of the indoor unit (start of the air conditioning operation) is linked with the start of the operation of the motor for the blower fan mounted on the indoor unit, and the current consumption due to the operation of the motor is reduced. By determining, the outdoor unit can determine the start of the air conditioning operation of the indoor unit. More specifically, the indoor unit and the outdoor unit are connected by two AC power lines and one signal line (whichever one of the AC power lines is shared) to supply AC power to the indoor unit. By performing the operation via the outdoor unit, even when the control circuit of the outdoor unit is stopped, when the electric motor is operated in the indoor unit, at least that much current increases on the AC power line. That is, the current flowing from the outdoor unit of the AC power line to the indoor unit increases. This increase in current is detected using CT, and when the current value detected by this CT exceeds a predetermined value, the relay is energized to activate the control circuit of the outdoor unit. Therefore, the outdoor unit only needs to include at least a switching circuit for exciting the relay and a CT for detecting current.

In order to solve the above problems, the present invention has a refrigeration cycle in which at least a refrigerant compressor driven by an electric element, a heat source side heat exchanger, a decompression device, and a use side heat exchanger are connected in an annular shape by a refrigerant pipe, The refrigeration cycle components are separately installed in an indoor unit and an outdoor unit, and an electric motor that drives the blower fan of the use-side heat exchanger is provided in the indoor unit to drive the electric motor. In the air conditioner configured to supply the electric power of the outdoor unit through the outdoor unit,
The indoor unit and the outdoor unit are connected by a first power line through which an alternating current flows, a second power line, and a signal line that transmits a signal using one of these power lines as a shared line, Commercial AC power is connected in the outdoor unit to the first power line and the second power line, and the outdoor unit is connected to the first power line or the second power line from the commercial AC power. A current detector for detecting an alternating current flowing through one of the switches, a switch for performing circuit communication when a current value detected by the current detector exceeds a predetermined reference value, and the commercial And an outdoor control circuit that controls the driving of the electric element, and the indoor unit is provided in the indoor unit before being obtained via the first power line and the second power line. An indoor side control circuit for controlling supply of commercial AC power to the electric motor, and the indoor side control circuit starts driving the electric motor in response to the start of an air conditioning operation, and after the electric motor is driven, Signals are exchanged with the outdoor unit control circuit of the outer unit via a signal line.

  With this configuration, a change in current consumed in the indoor unit can be detected by the outdoor unit, and the operation of the outdoor control circuit of the outdoor unit can be started.

  According to a second aspect of the present invention, in addition to the air conditioner according to the first aspect, the predetermined reference value for the communication operation of the switch includes at least a current consumed by the electric motor. It is.

  With this configuration, the outdoor control circuit of the outdoor unit can be driven by at least the electric motor driving.

  In the invention of claim 3, in addition to the air conditioner of claim 2, the switch comprises a normally open contact piece of a relay that constitutes a bypass circuit that bypasses the circuit after the circuit performs a communication operation. The normally open contact piece is closed by exciting the relay with an outdoor control circuit.

  With this configuration, when the outdoor control circuit starts operation, a power supply self-holding circuit is formed.

  According to a fourth aspect of the present invention, in addition to the air conditioner according to the first to third aspects, the operation of the electric motor mounted in the indoor unit is started when the operation is started.

  With this configuration, the operation of the electric motor is started in conjunction with the start of operation of the indoor unit.

  According to a fifth aspect of the present invention, in addition to the air conditioner according to the fourth aspect, the outdoor outdoor control circuit includes a microcomputer that starts operation when supplied with the commercial AC power, and the microcomputer is predetermined. After starting the obtained operation, a signal for determining the start of the air conditioning operation is acquired via the signal line to the indoor side control circuit of the indoor unit, and when the start of the air conditioning operation cannot be determined, the circuit of the switch is set. It is intended to open.

  By comprising in this way, after the outdoor side control circuit of an outdoor unit starts operation, it can suppress a malfunction by exchanging a signal with the indoor side control circuit of an indoor unit and judging the start of an air conditioning operation. Is.

  According to a sixth aspect of the present invention, in addition to the air conditioner according to the fourth aspect, a switching circuit is provided for blocking the flow of the alternating current to the current detector after the normally open contact piece of the relay is closed. It is a thing.

  By comprising in this way, after an air-conditioning driving | operation of an air conditioner is started, it interrupts | blocks that an electric current flows into an electric current detector.

The air conditioner of the present invention detects the current flowing through the power line when the indoor unit and the indoor unit are connected by three lines (two power lines and one signal line). Since the operation of the outdoor control circuit of the outdoor unit is started, the operation of the outdoor control circuit is used to start the air conditioning operation of the indoor unit using the existing three lines without exchanging special signals. It can be interlocked and can reduce standby power in the outdoor unit when the indoor unit is not performing the air conditioning operation.

1 is a schematic electric circuit diagram of an air conditioner according to an embodiment of the present invention.

  Hereinafter, an air conditioner as an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic electric circuit diagram of an air conditioner composed of an indoor unit 1 and an outdoor unit 2. The outdoor unit 1 and the outdoor unit 2 are connected by three lines of power lines 3 and 4 and a signal line 5 through which AC power flows. The air conditioner includes components of a refrigerant compressor driven by the electric element 6, a heat source side heat exchanger (not shown), a pressure reducing device (not shown), and a use side heat exchanger (not shown). It has a refrigeration cycle connected in an annular shape with a refrigerant pipe, the indoor unit 1 is equipped with a use side heat exchanger, and the outdoor unit is equipped with a refrigerant compressor, a heat source side heat exchanger, and a pressure reducing device. . The components of the refrigeration cycle that are separately mounted on the indoor unit 1 and the outdoor unit 2 are connected to each other by a refrigerant pipe. The outdoor unit 2 is equipped with a four-way switching valve 7, and the refrigerant flow discharged from the refrigerant compressor is changed to the heat source side heat exchanger, the pressure reducing device, the use side heat exchanger in this order, or the use side heat exchanger. The refrigerant piping is arranged so that the pressure reducing device and the heat source side heat exchanger can be selectively switched in this order.

  8 is an electric motor that drives a blower fan that blows air to the heat source side heat exchanger of the outdoor unit 2, and is connected to the power supply circuit 9 of the outdoor unit 2 together with the electric element 6 that drives the refrigerant compressor and the four-way switching valve 7. The energization is controlled.

  This power supply circuit 9 is connected to power supply buses 10 and 11 in the outdoor unit 2 connected to the power supply lines 3 and 4, a microcomputer 12 (corresponding to the outdoor control circuit) for controlling the operation of the indoor unit 2, and signal lines The operation power is also supplied to the outdoor communication circuit 13 that exchanges signals with the indoor unit 1 via 5.

  The four-way switching valve 7 switches the flow of the refrigerant when a predetermined direct current is supplied from the power supply circuit 9, and the supply of the direct current is controlled by the power supply circuit 9 by a signal from the microcomputer 12. The electric motor 8 is an induction motor having two speed control taps for low speed and high speed, and the power supply circuit 9 switches which speed control tap the AC current is supplied to in response to a signal from the microcomputer 12. Yes, the electric motor 8 can be switched to stop, low speed, and high speed 3rd speed. If the electric element 6 is an induction motor similar to the electric motor 8, the power supply circuit 9 can perform ON / OFF control of the operation of the refrigerant compressor by switching the supply / interruption of the alternating current according to the signal from the microcomputer 12. it can. The capacity of the refrigerant compressor can be varied by changing the frequency and voltage of the AC power supplied to the electric element 6 using inverter technology. Further, when a DC brushless motor is used as the electric element 6, the ability of the refrigerant compressor is similarly changed by changing the energization timing and applied voltage of each stator winding in accordance with the rotational position of the rotor. I'm going. The operating capacity of the refrigerant compressor can be changed based on the air conditioning load.

  The power supply bus 10 extending from the power supply circuit 9 to the power supply line 3 is switched in order from the power supply circuit 9 to the PTC element 14 for limiting current, the normally open contact piece 15 (relay contact piece corresponding to a switch), and the CT (current detector) 17 switching. A contact piece (relay contact piece corresponding to a changeover switch) 18 is connected. Reference numeral 16 denotes a normally open contact piece (relay contact piece corresponding to a switch), which is connected in parallel to a series circuit of the PTC element 14 and the normally open contact piece 15. The switching contact 18 is for switching between two contacts of the normally open A contact side and the normally closed B contact side, and the CT 17 flows to the power supply bus 10 when the switching contact 18 is on the normally closed B setting side. It detects AC current. The microcomputer 12 controls opening and closing of the normally open contact piece 16 and switching of the switching contact piece 18. Therefore, the normally open contact piece 16 and the switching contact piece 18 are in the state shown in the figure when the microcomputer 12 is not operating.

  Reference numeral 19 denotes a power plug connected to a commercial AC power source. An AC current obtained through the power plug is supplied to the power buses 10 and 11 in the outdoor unit 2. The power bus 10 has a normally open contact 15. And the switching contact piece 18.

  Reference numeral 20 denotes an auxiliary power circuit, which is connected to the power buses 10 and 11 at a position where an alternating current from the power plug 19 can be directly obtained. The auxiliary power circuit 20 supplies driving power to a comparator 21 and a reference current setting unit 22 that supplies a reference voltage to one input of the comparator. The normally open contact piece 15 is switched by the output of the comparator 21. The other input of the comparator 21 is applied after the output of CT17 is converted into a voltage corresponding to the current value detected by CT17 by a rectifying / smoothing circuit comprising a rectifier diode 23, a resistor 24 and a capacitor 25. Note that full-wave rectification may be used for rectification to increase the output. Therefore, when the voltage corresponding to the current detected by CT17 exceeds the voltage corresponding to the set current set by the reference current setting device, the output of the comparator 21 is inverted. In response to the reversal of the output, the normally open contact piece 15 is closed to enable supply of an alternating current from the power supply bus 10 to the power supply circuit 9. In the comparator 21 shown in the figure, the output voltage becomes 0 voltage so that the relay coil is excited and the normally open contact piece 15 is closed. However, the output voltage of the comparator 21 is a high voltage (5 to 5). It may be configured to excite the relay coil.

  In the outdoor unit 2 configured as described above, in the illustrated stop state, the alternating current is not supplied to the power supply circuit 9 and the microcomputer 12 is in the stop state, and the electric element 6, the electric motor 8, and the four-way switching valve 7. Also not energized. Since the auxiliary power supply circuit 20 is operated by being supplied with an alternating current, the comparator 21 is operating. When the current detected by the CT 17 exceeds the value set by the reference current setting device 22, the output of the comparator 21 is increased. It reverses and the normally open contact piece 15 is closed.

  When the normally open contact piece 15 is closed, an alternating current from the power plug 19 is supplied to the power circuit 9, and operating power is supplied from the power circuit 9 to the microcomputer 12. The initialization of the microcomputer 12 is completed, and a predetermined operation is started. The microcomputer 12 closes the normally open contact piece 16 to ensure the supply of alternating current to the power supply circuit 9 regardless of whether the normally open contact piece 15 is opened or closed, and the operation of the microcomputer 12 is continued.

  The normally open contact piece 16 is a contact piece that is closed by exciting a coil of a relay (not shown), and is energized through a drive circuit of the relay in response to a signal from the microcomputer 12. Similarly, the switching contact piece 18 switches the contact piece between the A contact side and the B contact side in response to a signal from the microcomputer 12. This switching contact piece 18 is switched from the B contact side to the A contact side in the same manner as the normally open contact piece 16 is closed, and the output of the comparator 21 is not reversed regardless of the current value detected by the CT 17. The opening piece 15 remains open.

  Therefore, the operation of the microcomputer 12 is continued until the normally open contact piece 16 is opened by the microcomputer 12. After closing the normally open contact piece 16 and switching the switching contact piece 18, whether or not the indoor unit 1 is in an air conditioning operation state via the communication circuit 13 and the signal line 5, that is, the indoor unit 1 is the user. A signal for requesting information on whether or not the air-conditioning operation is automatically started by direct operation or timer operation is output. The microcomputer 12 keeps the normally open contact piece 16 closed when the signal transmitted from the indoor unit 1 via the signal line 5 includes a signal indicating that the air conditioning operation is in progress. The switching contact piece 18 is maintained in the state switched to the A contact side and the operation is maintained. If the signal transmitted from the outdoor unit 1 does not include a signal indicating that it is in the air conditioning operation state, it is determined that the output inversion of the previous comparator 21 is due to a malfunction and the normally open contact piece 16 is The switching contact piece 18 is returned to the B contact side, and the indoor unit 2 returns to the stopped state.

  The indoor unit 1 includes a microcomputer 26 (corresponding to an indoor control circuit) that controls the operation of the indoor unit 1, an indoor communication circuit 27 that is connected to the signal line 5 and exchanges signals with the outdoor unit 2, A signal transmitted in response to the key operation from the inner power supply circuit 28, the electric motor 29 for controlling the supply of power from the power supply circuit 28 and driving the blower fan for blowing air to the use side heat exchanger, and the remote controller 31 A receiving circuit 30 that receives (for example, an infrared signal), demodulates it, and outputs it to the microcomputer 26 is provided.

  The microcomputer 26 starts the operation of the electric motor 29 via the power supply circuit 8 when the operation start time by the operation of the remote controller 31 or the direct operation of the switch provided in the indoor unit 1 or the timer operation is reached. As the electric motor 29, an electric element mounted on the outdoor unit 2, an induction motor, a brushless motor, or the like can be used similarly to the electric motor, and the number of rotations can be controlled. The rotation speed of the electric motor 29 is automatically controlled based on the room temperature (controlled temperature) and the set temperature (target temperature). Alternatively, the number of rotations is controlled by the user. The minimum rotational speed of the electric motor 29 is set in terms of the structure and characteristics of both the induction motor and the brushless motor, and the electric motor 29 is operated at the minimum rotational speed or higher. Therefore, as long as the electric motor 29 is in operation, the amount of electricity exceeding the current required for the minimum rotational speed is consumed. The current consumed by the electric motor 29 is supplied through the power circuit 28, the power lines 3 and 4, the outdoor unit 2, the CT 27, and the power plug 19.

When the air conditioning operation is started in the indoor unit 1 and the operation of the electric motor 29 is started, the drive current of the electric motor 29 is detected by the CT 17 of the outdoor unit 2, and the output of the comparator 21 of the outdoor unit 2 is inverted and always The open contact piece 15 is closed and the microcomputer 12 starts to operate. When the air conditioning operation is stopped, a stop signal is transmitted from the indoor unit 1 to the microcomputer 12 of the outdoor unit 2, and the microcomputer 12 opens the normally open contact piece 16 to stop the operation.

DESCRIPTION OF SYMBOLS 1 Indoor unit 2 Outdoor unit 3, 4 Power supply line 5 Signal line 6 Electric element 9 Power supply circuit 12 Microcomputer 15 Normally open contact piece 17 CT
18 Switching piece
26 Microcomputer 29 Electric motor

Claims (6)

At least a refrigerant compressor driven by an electric element, a heat source side heat exchanger, a pressure reducing device, and a use side heat exchanger are connected in a ring shape with refrigerant piping, and the components of the refrigeration cycle are an indoor unit. In addition to being mounted separately from the outdoor unit, the indoor unit is provided with an electric motor for driving the blower fan of the use side heat exchanger, and electric power for driving the electric motor is supplied via the outdoor unit. In the air conditioner
The indoor unit and the outdoor unit are connected by a first power line through which an alternating current flows, a second power line, and a signal line that transmits a signal using one of these power lines as a shared line, Commercial AC power is connected in the outdoor unit to the first power line and the second power line, and either the first power line or the second power line is connected to the outdoor unit from the commercial AC power. A current detector that detects the alternating current flowing through the switch, a switch that performs circuit communication when the current value detected by the current detector exceeds a predetermined reference value, and the commercial power supply via the switch. An outdoor control circuit that is supplied with AC power and controls driving of the electric element, and the indoor unit includes the quotient obtained through the first power line and the second power line. An indoor control circuit that controls the supply of AC power to the electric motor. The indoor control circuit starts driving the electric motor in response to the start of an air conditioning operation, and after the electric motor is driven, An air conditioner that performs transmission and reception of signals through a signal line with the outdoor control circuit of the unit. 2. The air conditioner according to claim 1, wherein the predetermined reference value for performing the communication operation of the switch includes at least a current consumed by the electric motor. The switch has a normally open contact piece of a relay that constitutes a bypass circuit that bypasses the circuit after the circuit has been connected, and the normally open contact piece is closed by exciting the relay in an outdoor control circuit. The air conditioner according to claim 2. The air conditioner according to any one of claims 1 to 3, wherein the operation of the electric motor mounted on the indoor unit is started when the operation is started. The first outdoor side control circuit has a microcomputer that starts operation when supplied with the commercial AC power, and after the microcomputer starts a predetermined operation, the indoor side control circuit of the indoor unit via the signal line 5. The air conditioner according to claim 4, wherein a signal for determining the start of the air conditioning operation is acquired and the circuit of the switch is opened when the start of the air conditioning operation cannot be determined. The air conditioner according to claim 4, further comprising a switching circuit that blocks the flow of the alternating current to the current detector after the normally open contact piece of the relay is closed.

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