JP4667304B2 - Air conditioner - Google Patents

Description

  The present invention relates to an air conditioner that includes an indoor unit and an outdoor unit, and that drives / stops a motor provided in the outdoor unit by turning on / off power supplied from the indoor unit to the outdoor unit.

  In offices or general households, large-capacity air conditioners (air conditioners) have come to be used, and in order to reduce the installation space in the room, it is separated into indoor units and outdoor units, and compressors (compressors), etc. Separation type air conditioners that are installed in outdoor units are becoming mainstream.

  For example, when the room temperature is adjusted during cooling, the room temperature detected by the temperature sensor is compared with the set temperature, and when the room temperature is lowered, the compressor is turned on (more specifically, the compressor motor is set to a predetermined value). Rotate at the number of revolutions). When the room temperature reaches the set temperature, the compressor is turned off (more specifically, the compressor motor is stopped).

  When placing relays (electromagnetic relays) for turning on / off motors for large-capacity compressors in indoor units, it is necessary to use large-capacity relays with a large contact rating, which increases the operating noise of the relays. In addition to causing discomfort to the person, the occupied volume inside the indoor unit increases, and the indoor unit cannot be reduced. Therefore, the compressor motor was turned on / off using a small relay with a relatively small contact rating and capacity.

  However, for example, when a motor for a compressor used in a large air conditioner of 24000 BTU (British Thermal Unit) class is turned on, a starting current of about 70 A is applied to the winding of the motor for a time of about several hundred ms. When this starting current flows during the bounce time of the relay contact (for example, about several ms), there is a problem that contact welding of the relay occurs and the life of the relay provided in the indoor unit is shortened.

  In order to extend the life of the relay, by applying a voltage higher than the rated voltage to the relay coil for a short time in the initial stage of relay operation, the attractive force of the coil part is increased at the initial stage of relay operation, and the amount of arc generated due to contact bounce, etc. A relay drive circuit that can improve the durability of contacts by reducing the above has been proposed (see Patent Document 1).

  Also, in the conventional separation type air conditioner, in order to turn on / off the compressor motor, a large relay with a large contact rating is arranged in the outdoor unit, and the small unit placed in the indoor unit is an outdoor unit. A method of controlling a large-capacity relay has been performed.

  FIG. 3 is a block diagram showing a main configuration of a conventional air conditioner 200. The air conditioner 200 includes an indoor unit 30, an outdoor unit 40, and the like, and a power line is wired between the indoor unit 30 and the outdoor unit 40.

  The indoor unit 30 includes input terminals A1, A2 to which a power line from a 50/60 Hz AC power source is connected, output terminals B1, B2, B3 for outputting an AC voltage to the outdoor unit 40, an input terminal A1, and an output terminal B1. A relay 31 having contacts 31a and 31b, a control unit 32 configured by a Mycolo computer and controlling the operation of the relay 31, and the like. The input terminal A1 is connected to the output terminal B3.

  The outdoor unit 40 includes input terminals C1, C2, and C3 to which an AC voltage from the indoor unit 30 is input through power lines (wiring) connected to the output terminals B1, B2, and B3 of the indoor unit 30, and a motor for the compressor. 42, a capacitor 43 connected between the terminals 42b and 42c of the motor 42 for shifting the phase of the voltage, a motor 44 for a relatively small capacity blower fan, and a phase of the voltage connected between the terminals 44b and 44c of the motor 44. And a relay 41 having contacts 41a and 41b and a coil 411 (electromagnetic coil) connected between the terminal 42a of the motor 42 and the input terminal C3.

  The terminal 44a of the motor 44 and one end 411a of the coil 411 are connected to the input terminal C1, and the other end 411b of the coil 411 is connected to the terminal 42c of the motor 42 and the terminal 44b of the motor 44, and to the input terminal C2. Connected.

When driving (rotating) the motor 42 for the compressor, the control unit 32 outputs a control signal for rotating the motor 42 to the driving unit (for example, an electromagnetic coil) of the relay 31 so that the contact 31a of the relay 31 and Close 31b. As a result, an AC voltage is applied to the coil 411 of the relay 41, and the contacts 41a and 41b of the relay 41 are closed about several tens of milliseconds after the AC voltage is applied to the coil 411. After a ms starting current (for example, about 70 A) flows, a steady current (for example, about 16 A) flows. Since the bounce time of the contacts 31a and 31b of the relay 31 is about several milliseconds, the contacts 31a and 31b are already closed when the starting current starts to flow through the motor 42, and there is no possibility of contact welding.
JP-A-8-279414

  However, the relay drive circuit disclosed in Patent Document 1 has a relatively low power supply voltage of 12 V DC and can improve the contact durability of a relay with a small capacity contact, but is used in an air conditioner. There is a problem that it cannot be applied to open and close an AC voltage circuit through which a large current flows, such as on / off of a compressor.

  In the example of the conventional air conditioner, although it is possible to prevent contact welding of a small-capacity relay disposed in the indoor unit, the indoor unit and the outdoor unit are provided with respective relays. There is a problem that the number of power supply wires between the outdoor unit and the outdoor unit increases.

  The present invention has been made in view of such circumstances, and is provided in the indoor unit, and is provided in the outdoor unit, the first electromagnetic relay that turns on / off the power supplied to the outdoor unit, and the first unit A second electromagnetic relay for turning on / off the electric power supplied to the motor in accordance with the operation of the electromagnetic relay, and the electric power to the coil of the second electromagnetic relay and the motor through the contact of the first electromagnetic relay Air conditioning that can reduce the number of wires between the indoor unit and the outdoor unit without causing contact welding even when a small-capacity electromagnetic relay is used for the indoor unit The purpose is to provide a machine.

  Another object of the present invention is that the motor is a compressor motor, so that the number of wires between the indoor unit and the outdoor unit can be reduced even when a small capacity electromagnetic relay is used for the indoor unit. An object of the present invention is to provide an air conditioner that can turn on / off a compressor without increasing the number.

An air conditioner according to the present invention includes an indoor unit and an outdoor unit, and turns on / off power supplied from the indoor unit to the outdoor unit to drive / stop a motor provided in the outdoor unit. A first electromagnetic relay provided in the indoor unit for turning on / off electric power supplied to the outdoor unit, and provided in the outdoor unit and having a larger capacity than the first electromagnetic relay and the first electromagnetic relay . A second electromagnetic relay for turning on / off the electric power supplied to the motor in accordance with the operation of the first electromagnetic relay, and the coil and motor of the second electromagnetic relay through the contact of the first electromagnetic relay The second electromagnetic relay is connected to the motor, and the other contact of the second electromagnetic relay is connected to the coil of the second electromagnetic relay. Connected, the first electromagnetic Contacts Leh Yes connected to the other contact, current flows through the coil of the first electromagnetic relay, the contact of the first electromagnetic relay after the ON state, the second electromagnetic relay It is characterized in that a current flows through the coil and the contact of the second electromagnetic relay is turned on.

  The air conditioner according to the present invention is characterized in that the motor is a compressor motor.

  In the present invention, when the first electromagnetic relay provided in the indoor unit is on, that is, when the contact of the first electromagnetic relay is closed, the power supplied from the indoor unit to the outdoor unit (for example, AC voltage) ) Is first supplied to the coil of the second electromagnetic relay disposed in the outdoor unit through the contact of the first electromagnetic relay. A current flows through the coil of the second electromagnetic relay, and the second electromagnetic relay is turned on after a predetermined time (longer than the bounce time of the first electromagnetic relay) has elapsed, that is, the contact of the second electromagnetic relay is closed. . By closing the contact of the second electromagnetic relay, power is supplied to the motor of the outdoor unit through the contact of the first electromagnetic relay. As a result, during the initial bounce time when the first electromagnetic relay is turned on and the contact of the first electromagnetic relay is closed, the contact of the second electromagnetic relay is not closed. Does not flow and does not cause contact welding due to bounce. In addition, since power is supplied to both the coil and the motor of the second electromagnetic relay through the contacts of the first electromagnetic relay, the number of wires between the indoor unit and the outdoor unit can be reduced as compared with the related art.

Also, it is connected to one one of the contacts of the second electromagnetic relay to the motor, is connected to the other contact of the second electromagnetic relay coil of the second electromagnetic relay. Further, the contact of the first electromagnetic relay is connected to the other contact of the second electromagnetic relay. That is, the contact of the first electromagnetic relay is connected to the motor through the coil of the second electromagnetic relay and the contact of the second electromagnetic relay. Thereby, the electric power from the indoor unit is supplied to both the motor through the contact of the first electromagnetic relay and the coil of the second electromagnetic relay and the contact of the second electromagnetic relay.

  In the present invention, the motor is a compressor motor.

  In the present invention, the first electromagnetic relay provided in the indoor unit and for turning on / off the power supplied to the outdoor unit, and provided in the outdoor unit, according to the operation of the first electromagnetic relay, A second electromagnetic relay for turning on / off the electric power supplied to the motor, and supplying electric power to the coil of the second electromagnetic relay and the motor through the contact of the first electromagnetic relay. Even when a small capacity electromagnetic relay is used, the number of wires between the indoor unit and the outdoor unit can be reduced without causing contact welding.

Further, one contact of the second electromagnetic relay is connected to the motor, and the other contact of the second electromagnetic relay is connected to the coil of the second electromagnetic relay. By connecting a contact to the other contact, even if a small capacity electromagnetic relay is used for the indoor unit, the number of wires between the indoor unit and the outdoor unit is reduced without causing contact welding. can do.

  In the present invention, since the motor is a compressor motor, the number of wires between the indoor unit and the outdoor unit can be increased even when a small capacity electromagnetic relay is used for the indoor unit. The compressor can be turned on / off.

  Hereinafter, an air conditioner according to the present invention will be described with reference to the drawings showing embodiments. FIG. 1 is a block diagram showing a main configuration of an air conditioner 100 according to the present invention. The air conditioner 100 includes an indoor unit 10, an outdoor unit 20, and the like, and a power line is wired between the indoor unit 10 and the outdoor unit 20.

  The indoor unit 10 includes input terminals A1 and A2 to which a power line from a 50/60 Hz AC power source is connected, output terminals B1 and B2 that output an AC voltage to the outdoor unit 20, and a space between the input terminal A1 and the output terminal B1. And a relay 11 (electromagnetic relay) having contacts 11a and 11b, a control unit 12 configured by a microcomputer and controlling the operation of the relay 11. In addition, since the relay 11 provided in the indoor unit 10 needs to have a relatively small current capacity, it may be any of a small mechanical relay, a solid state relay for AC switching, and the like.

  The outdoor unit 20 includes input terminals C1 and C2 into which an AC voltage from the indoor unit 10 is input through power lines (wiring) connected to the output terminals B1 and B2 of the indoor unit 10, a compressor motor 22, and a motor. 22 is connected between terminals 22b and 22c for shifting the phase of voltage, motor 24 for a relatively small capacity blower fan, and connected between terminals 24b and 24c of motor 24 to shift the phase of voltage. And a relay 21 (electromagnetic relay) having contacts 21a and 21b and a coil 211 connected between the terminal 22a of the motor 22 and the input terminal C1.

  The terminal 24a of the motor 24 and one end 211a of the coil 211 are connected to the input terminal C1, and the other end 211b of the coil 211 is connected to the terminal 22c of the motor 22 and the terminal 24b of the motor 24, and to the input terminal C2. Connected. One end 211 a of the coil 211 is connected to the contact 21 a of the relay 21.

  When driving (rotating) the compressor motor 22, the control unit 12 outputs a control signal for rotating the motor 22 to close the contacts 11 a and 11 b of the relay 11. As a result, an AC voltage is applied to the coil 211 of the relay 21, and the contacts 21 a and 21 b of the relay 21 are closed about several tens of ms after the AC voltage is applied to the coil 211. After a ms starting current (for example, about 70 A) flows, a steady current (for example, about 16 A) flows. Since the bounce time of the contacts 11a and 11b of the relay 11 is about several milliseconds, the contacts 11a and 11b are already closed when the starting current starts to flow through the motor 22, and there is no possibility of contact welding.

  Since one end 211a of the coil 211 is connected to the contact 21a of the relay 21, electric power (AC voltage) supplied from the indoor unit 10 to the outdoor unit 20 is output from the output terminals B1 and B2 of the indoor unit 10 and the outdoor unit. The number of power supply lines between the indoor unit 10 and the outdoor unit 20 can be reduced by one compared to the conventional case (FIG. 3). it can. Thereby, the handling of the wiring between the indoor unit 10 and the outdoor unit 20 is facilitated, and the wiring work is further facilitated. Moreover, the number of terminals of the connection terminal terminal plate used in the indoor unit 10 and the outdoor unit 20 can be reduced, and space saving and cost reduction can be realized.

  FIG. 2 is a time chart for explaining the operation of the air conditioner 100 of the present invention. When a coil current (excitation current) flows through the coil of the relay 11 at the time t1 (FIG. 2 (a)), as shown in FIG. 2 (b), the contacts 11a and 11b of the relay 11 are connected for several ms. After turning on / off repeatedly (bounces), it turns on at time t2. In this case, t2-t1 is the bounce time.

  At time t2, an AC voltage is applied to the coil 211 of the relay 21 through the contacts 11a and 11b of the relay 11, and a coil current flows (FIG. 2 (c)). After a current flows through the coil 211 of the relay 21, the contacts 21a and 21b of the relay 21 start to be turned on at time t3, and are repeatedly turned on / off for several ms (bounce), and then turned on at time t4. (FIG. 2 (d)). In the case of the large-capacity relay 21, a time of several tens of ms (t4-t2 in the figure) is required until a current flows through the coil 211 and the contacts 21a and 21b are turned on.

  When the contacts 21a and 21b of the relay 21 are turned on at the time t4, the starting current (for example, about 70A) of the motor 22 flows through the contacts 11a and 11b of the relay 11 for about several hundreds ms, and then the rated current (for example, 16A) (Fig. 2 (e)). When the small capacity relay 11 of the indoor unit 10 is turned on and an AC voltage is applied to the coil 211 of the large capacity relay 21 of the outdoor unit 20, the contacts 21a and 21b are closed after a few tens of ms, and the motor 22 is started. Current flows. Since the bounce time has already elapsed for the contacts 11a and 11b of the relay 11, contact welding due to the starting current of the motor 22 does not occur, and deterioration of the relay 11 can be prevented.

  As described above, in the present invention, even when a small capacity relay is used for an indoor unit, the number of wires between the indoor unit and the outdoor unit is reduced without causing contact welding. can do. Further, even when a small-capacity relay is used for the indoor unit, the compressor can be turned on / off without increasing the number of wires between the indoor unit and the outdoor unit.

  In the above-described embodiment, the air conditioner using an AC motor has been described. However, the present invention is not limited to this, and an AC voltage is converted into a DC voltage, and a large-capacity DC motor is turned on / off. The present invention can also be applied to electric equipment. Further, the AC voltage is not limited to a single phase, and may be a case where a multiphase power source such as a three phase is used.

It is a block diagram which shows the principal part structure of the air conditioner which concerns on this invention. It is a time chart explaining operation | movement of the air conditioner of this invention. It is a block diagram which shows the principal part structure of the conventional air conditioner.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Indoor unit 11 Relay 12 Control part 20 Outdoor unit 21 Relay 22, 24 Motor 23, 25 Capacitor 211 Coil

Claims (2)

In an air conditioner comprising an indoor unit and an outdoor unit, and driving / stopping a motor provided in the outdoor unit by turning on / off power supplied from the indoor unit to the outdoor unit,
A first electromagnetic relay provided in the indoor unit and configured to turn on / off the power supplied to the outdoor unit;
A second electromagnetic relay that is provided in the outdoor unit and has a larger capacity than the first electromagnetic relay and turns on / off the electric power supplied to the motor in accordance with the operation of the first electromagnetic relay; With
It is configured to supply power to the coil and motor of the second electromagnetic relay through the contact of the first electromagnetic relay,
One contact of the second electromagnetic relay is connected to the motor;
The other contact of the second electromagnetic relay is connected to the coil of the second electromagnetic relay;
A contact of the first electromagnetic relay is connected to the other contact;
After the current flows through the coil of the first electromagnetic relay and the contact of the first electromagnetic relay is turned on, the current flows through the coil of the second electromagnetic relay, and the contact of the second electromagnetic relay An air conditioner that is configured to be turned on. The air conditioner according to claim 1, wherein the motor is a compressor motor.

Images