JPH09170562A - Control device for compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control device for a compressor capable of restraining wasteful consumption of electric power and restarting in a short period of time. SOLUTION: A contact point of an overload relay 4 is connected to a common contact point of a main coil 2 and an auxiliary coil 3 of a motor 1 for driving of a compressor and connected to one terminal of an alternating electric power source, the main coil 2 of the motor 1 is connected to the other terminal of the alternating electric power source through a main relay contact point 7, and at least an auxiliary relay contact point 8 is connected between the main relay contact point 7 and the auxiliary coil 3 of the motor 1. The motor 1 is changed over to a driving state by starting the motor 1 by switching on the main relay contact point 7 after switching on this auxiliary relay contact point 8 and by switching off the auxiliary relay contact point 8 thereafter, and restarting of the compressor at the time when the contact point of the overload relay 4 is switched on is carried out by switching on the auxiliary relay contact point 8 when the overload relay contact point is switched off.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a control device for a compressor such as a refrigerator or an air conditioner.

[0002]

2. Description of the Related Art FIG. 3 shows the configuration of a conventional compressor control device used in, for example, a refrigerator. With the configuration shown in the figure, for example, when the temperature of the refrigerator is controlled, the inside temperature detecting means 15
When the inside temperature from the inside is higher than the temperature set by the inside temperature setting means 14, the control unit 12 causes the relay coil 9
Is excited, the relay contact 7 is turned on, and the compressor driving motor 1 is started. When the internal temperature reaches the set temperature, the control unit 12 deenergizes the relay coil 9, turns off the relay contact 7, and stops the compressor driving motor 1.

In the auxiliary winding 3 of the compressor driving motor 1,
The operating capacitor 6 is connected in parallel to the series circuit of the PTC thermistor 13 which is a positive temperature coefficient thermistor and the starting capacitor 5, and when the compressor driving motor 1 is started, an AC current is applied to the main winding 2 and the auxiliary winding 3. It was done by pouring.

As the compressor driving motor 1 is started, the PTC thermistor 13 is heated by the Joule heat of the current flowing through the PTC thermistor 13, and the PT
The resistance value of the C thermistor 13 increased, and the auxiliary winding 3 was substantially connected to only the operating capacitor 6, and the compressor driving motor 1 was switched to the operating state.

When the overload relay 4 detects overheating of the compressor while the compressor started for temperature control by the control unit 12 is in operation, the contact point of the overload relay 4 is turned off. By doing so, the operation of the compressor is stopped. Then, when the overheat of the compressor subsides, the contact point of the overload relay 4 is turned on, and the startup and operation of the compressor are repeated again.

[0006]

Conventionally, as described above, the switching of the compressor from the starting state to the operating state is performed substantially by using the PTC thermistor 13 as a high resistance and thus starting the capacitor 5.
Was performed by disconnecting the auxiliary winding 3 from the
Since the C thermistor 13 itself cannot maintain a high resistance unless it is heated by the Joule heat of the current flowing through it, PT
The C thermistor 13 must always be flowing a current though it is small, but there is a problem that power is wasted.

When such a PTC thermistor 13 is used for starting the compressor driving motor 1, the overload relay 4 operates while the compressor driving motor 1 is being started and is operating. The contact was turned off, and then the PTC that was heated when the compressor cooled and the contact was turned on.
If the temperature of the thermistor 13 is not sufficiently lowered, there is a problem that the compressor driving motor 1 cannot be restarted. In order to solve this, for example, Jikkou Sho 57-226
As described in the publication, it is proposed to mount the PTC thermistor on the outer wall of the compressor hermetic case, but then an extra installation space for mounting the thermistor must be provided, and in that way. However, it is necessary to wait for the temperature of the PTC thermistor to drop sufficiently, and there is a problem that the PTC thermistor cannot be restarted in a short time.

Therefore, an object of the present invention is to provide a control device for a compressor, which uses a relay in place of a conventional PTC thermistor to suppress wasteful consumption of electric power and which can be restarted in a short time. To do.

[0009]

According to a first aspect of the present invention, an overload relay contact is connected to a common connection point of a main winding and an auxiliary winding of a motor for driving a compressor, and one of the AC power supplies is connected. The main winding of the motor is connected to the other terminal of the AC power supply via the main relay contact, and at least the auxiliary relay contact is connected between the main relay contact and the auxiliary winding of the motor. At the same time, an overload detector for detecting that the overload relay is turned off and a signal from the overload detector are input to turn on the contacts of the main relay and the auxiliary relay.
A control unit for controlling N and OFF is provided, and after turning on the auxiliary relay contact, the main relay contact is turned on to start the motor, and then the auxiliary relay contact is turned off to switch the motor to an operating state. The controller receives the overload relay contact OFF detection signal from the overload detector and turns on the auxiliary relay contact to restart the compressor when the overload relay contact is turned on. Is characterized by.

According to a second aspect of the present invention, in the structure according to the first aspect, the control section turns off the main relay contact when the overload detector detects that the overload relay contact is turned off. However, it is characterized in that the main relay contact and the auxiliary relay contact are turned on when the overload relay is turned on.

According to a third aspect of the present invention, in the configuration according to the first aspect, the control section turns off the main relay contact when the overload detector detects that the overload relay contact is turned off. The auxiliary relay contact is turned on, and the main relay contact is turned on when the overload relay is turned on.

According to a fourth aspect of the present invention, an overload relay contact is connected to a common connection point of a main winding and an auxiliary winding of a motor for driving a compressor to connect to one terminal of an AC power source. The main winding of the motor is connected to the other terminal of the power supply via a main relay contact, and a series circuit of an auxiliary relay contact and a starting capacitor is provided between the main relay contact and the auxiliary winding of the motor. A series-parallel circuit in which operating capacitors are connected in parallel is connected, and an overload detector that detects that the overload relay is turned off and a signal from the overload detector are input to the main relay and the auxiliary relay. ON the contact of
A control unit for OFF control is provided and the auxiliary relay contact is turned ON.
After N, the main relay contact is turned on to start the motor, and then the auxiliary relay contact is turned off to switch the motor to an operating state, and an overload relay contact OFF detection signal from the overload detector Is received by the control unit and the auxiliary relay contact is turned on, thereby restarting the compressor when the load relay contact is turned on.

According to a fifth aspect of the present invention, in the structure according to the fourth aspect, the control section turns off the main relay contact when the overload detector detects that the overload relay contact is turned off. However, it is characterized in that the main relay contact and the auxiliary relay contact are turned on when the overload relay is turned on.

According to a sixth aspect of the present invention, in the structure according to the fourth aspect, the control section turns off the main relay contact when the overload detector detects that the overload relay contact is turned off. The auxiliary relay contact is turned on, and the main relay contact is turned on when the overload relay is turned on.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an embodiment of a control device according to the present invention. For example, it is a block diagram of a device for controlling a motor 1 for driving a compressor such as a refrigerator or an air conditioner. is there. In the configuration of the figure, the same reference numerals as those in FIG. 3 indicate the same or corresponding portions, and the difference from the configuration of FIG.
Instead of driving the auxiliary relay coil 10
This is the point that an auxiliary relay contact 8 that turns on and off is provided, and that the overload detector 11 that takes in the voltage generated in the operating capacitor 6 to the control unit 12 is provided.

The case where the compressor control device having the above-described structure is applied to the control of the refrigerator compressor will be described below.

The overload detector 11 includes capacitors 5, 6,
The AC voltage generated at both ends of the series-parallel circuit of the auxiliary relay contact 8 is input and converted into a DC signal voltage, and the control unit 12
To enter.

The control unit 12 controls the inside temperature setting signal from the connected inside temperature setting means 14 and the inside temperature detecting means 15.
When the internal temperature is higher than the set temperature, the main relay coil 9 is driven and the contact (main relay contact) 7 is turned on, and the compressor is compared with the internal temperature signal from the compressor. The drive motor 1 is started.

Here, the main relay contact 7 is a normally open contact and is turned on when the main relay coil 9 is driven by the controller 12, whereas the auxiliary relay contact 8 is a normally closed contact. Therefore, the auxiliary relay coil 10 is turned off by being driven by the control unit 12. Therefore, the pre-compressor auxiliary relay contact 8 is ON.

With the auxiliary relays 8 and 9 turned on,
When the main relay contact 7 is turned on, a current flows from the AC power supply AC100V to the main winding 2 of the compressor driving motor 1 via the overload relay 4, and a series circuit of the starting capacitor 5 and the auxiliary relay contact 8 is provided. A current flows through the auxiliary winding 3 through the series-parallel circuit of the operating capacitors 6 connected in parallel to this series circuit, and the compressor driving motor 1 is started.

After a predetermined time in which the compressor driving motor 1 is activated and is in an operating state, the control unit 12 drives the auxiliary relay coil 10 to turn off its contact 8. Accordingly, thereafter, the compressor driving motor 1 is in an operating state, and the compressor driving motor 1 is operated until the internal temperature reaches the set temperature.

When the internal temperature reaches the set temperature, the control unit 12
Stops driving the main relay coil 9 to open the main relay contact 7, and then de-excites the auxiliary relay coil 10 to close the auxiliary relay contact 8. As a result, the operation of the compressor driving motor 1 is stopped, and the state before starting is restored. After that, the operation and stop of the compressor driving motor 1 described above are repeated according to the difference between the internal temperature and the set temperature.

Next, a case where the operation of the overload relay 4 changes from the ON state to the OFF state will be described.

When the compressor driving motor 1 is overheated due to some cause during operation of the compressor driving motor 1, the overload relay 4 which is a thermostat is used.
Turns off. Therefore, the AC current supplied from the AC power supply AC100V to the compressor driving motor 1 is cut off,
The operation of the compressor driving motor 1 is stopped.

As a result, the overload detector 11 detects that the electric power that has been supplied to the main winding 2 and the auxiliary winding 3 of the compressor driving motor 1 has been cut off, and the overload detector 11 informs the control unit 12. The detection signal is sent. Then, the control unit 12 determines that the overload relay 4 has changed to the OFF state, and de-energizes the auxiliary relay coil 10 so that the auxiliary relay contact 8
Turn ON.

After a while, when the overheating and overheating of the compressor driving motor 1 is reduced and the overload relay 4 changes to the ON state, the AC voltage from the AC power supply AC100V is immediately applied to the main winding 2 of the compressor driving motor 1. And auxiliary winding 3
And the compressor drive motor 1 is restarted.

In this way, when the compressor is started and operated, there is no resistor that generates Joule heat due to the current in the circuit to which the AC power is supplied, so that no power is consumed and the conventional Energy saving can be achieved compared to the one at the same time, and at the same time, the compressor can be started and restarted quickly.

By the way, in the control device described above,
The overload detector 11 is configured using an AC-DC converter,
By detecting the presence or absence of a current flowing in the series-parallel circuit of the capacitors 5 and 6 and the auxiliary relay contact 8, the overload relay 4
The example in the case of determining the operating state of has been described. However, by slightly improving the functions of the overload detector 11 and the control unit 12, the control device of the compressor can be made more effective.

FIG. 2 shows an example thereof, and the same reference numerals as those in FIG. 1 indicate the same or corresponding portions, and the overload detector 11
Is turned on by the control signal from the control unit 12
In the N state, the operating state of the overload relay 4 is detected by extracting the voltage at both ends 20 and 21 of the series-parallel circuit of the capacitors 5 and 6 and the auxiliary relay contact 8 and detecting the current flowing there. The point of monitoring is the same as in the case of FIG. 1, but when the main relay contact 7 is in the OFF state, the voltage appearing at the one end 21 of the series-parallel circuit is applied to the extraction control section 12. There is.

With this configuration, when the overload relay 4 changes from the ON state to the OFF state, the compressor driving motor 1
The operation of detecting that the power supplied up to now to the main winding 2 and the auxiliary winding 3 has been cut off and sending the detection signal to the control unit 12 is the same as in the case of FIG.

Thereafter, in the case of this example, the control unit 12
Determines that the overload relay 4 has changed to OFF and deenergizes the main relay coil 9 and the auxiliary relay coil 10 to open the main relay contact 7 and close the auxiliary relay contact 8.

After a while, overheating of the compressor driving motor 1 is reduced and the overload relay 4 is restored (O
When changed to the N state), the AC voltage from the AC power supply AC100V appears at the one end 21 of the series-parallel circuit via the overload relay 4 and the auxiliary winding 3 of the compressor driving motor 1.
When this is detected by the overload detector 11, the control unit 12
It is determined that the overload relay 4 has changed to the ON state, and the main relay coil 9 is excited to close the main relay contact 7,
The compressor driving motor 1 is started again. In this case, the auxiliary relay contact 8 is closed before the main relay contact 7 is closed.

When the compressor driving motor 1 is started, the control unit 12 excites the auxiliary relay coil 10 to open the auxiliary relay contact 8 to bring the compressor driving motor 1 into an operating state.

The above operation is shown in the table below.

[0035]

[Table 1]

As described above, in the case of the configuration shown in FIG. 2, when the overload relay 4 is turned off and then turned on, the main relay contact 7 is turned off when the overload relay 4 is turned on. Since the voltage from the AC power supply is not applied to the overload relay 4 even when 4 is turned on, it is possible to prevent sparking of the contacts when the overload relay 4 is turned on.
The electrical wear of the contacts of the overload relay 4 can be prevented and the service life can be extended.

When the overload relay 4 is activated and turned on, the auxiliary relay contact 8 is already turned on when the compressor driving motor is restarted. Therefore, the main relay contact 7 is turned on.
When it is restarted, the spark at the auxiliary relay contact 8 can be prevented, and the electrical wear of the auxiliary relay contact can be reduced,
It is possible to extend the service life and select an auxiliary relay with a small contact capacity.

[0038]

According to the structure of the first aspect of the present invention, the compressor can be quickly started and restarted by switching and controlling the main relay and the auxiliary relay by the control unit.

When the compressor is started and operated,
Since there is no resistor that generates Joule heat in the circuit to which the AC power is supplied, there is no power consumption and energy can be saved.

According to the second aspect of the present invention, in addition to the effect of the first aspect, when the overload relay is turned off (operation) and then turned on (returned), it is turned on. When the overload relay is turned on, the voltage from the AC power supply is not applied to the overload relay even if the overload relay is turned on because the main relay contact is off. Sparks can be prevented, electrical wear on the contacts of the overload relay is prevented,
Long life can be achieved.

According to the third aspect of the present invention, in addition to the effect of the first aspect, when the overload relay is operated and turned on, the auxiliary relay contact is used when the compressor is restarted. Since it has already been turned on, when the main relay contact is turned on and restarted, sparks at the auxiliary relay contact can be prevented, electrical wear of the auxiliary relay contact can be reduced, and as a result, the auxiliary relay contact capacity can be reduced. You can select the one with the smallest

According to the configuration of claim 4 of the present invention, in addition to the effect of the configuration of claim 1, since the starting and operating capacitors are connected to the auxiliary coil,
The power factor of the compressor drive motor has been improved, and stable startup,
Driving is performed.

According to the fifth aspect of the present invention, in addition to the effect of the fourth aspect, when the overload relay is turned off (operation) and then turned on (returned), it is turned on. When the overload relay is turned on, the voltage from the AC power supply is not applied to the overload relay even if the overload relay is turned on because the main relay contact is off. Sparks can be prevented, electrical wear on the contacts of the overload relay is prevented,
Long life can be achieved.

According to the configuration of claim 6 of the present invention, in addition to the effect of the configuration of claim 4, when the overload relay is operated and turned on, the auxiliary relay contact is used when the compressor is restarted. Since it has already been turned on, when the main relay contact is turned on and restarted, sparks at the auxiliary relay contact can be prevented, electrical wear of the auxiliary relay contact can be reduced, and as a result, the auxiliary relay contact capacity can be reduced. Can be small.

[Brief description of the drawings]

FIG. 1 is a diagram showing an embodiment of a control device for starting, operating, and restarting a compressor according to the present invention.

FIG. 2 is a diagram showing another embodiment of the control device for starting, operating, and restarting the compressor according to the present invention.

FIG. 3 is a control device of a conventional compressor.

[Explanation of symbols]

 1 Compressor driving motor 2 Main winding 3 Auxiliary winding 4 Overload relay 7 Main relay contact 8 Auxiliary relay contact 9 Main relay coil 10 Auxiliary relay coil 11 Overload detector 12 Control unit

Claims (6)

[Claims] 1. An overload relay contact is connected to a common connection point between a main winding and an auxiliary winding of a motor for driving a compressor and is connected to one terminal of an AC power source, and is connected to the other terminal of the AC power source. Connect the main winding of the motor through a main relay contact, connect at least an auxiliary relay contact between the main relay contact and the auxiliary winding of the motor, and check that the overload relay is turned off. An overload detector for detecting and a control unit for inputting a signal from the overload detector to control ON / OFF of each contact of the main relay and the auxiliary relay are provided.
After turning on the auxiliary relay contact, turn on the main relay contact
By starting the motor, the auxiliary relay contact is turned off to switch the motor to the operating state, and the overload relay contact O from the overload detector is generated.
A control device for a compressor, wherein a control section receives an FF detection signal and turns on the auxiliary relay contact to restart the compressor when the overload relay contact is turned on. 2. The control section, when the overload detector detects that the overload relay contact is turned off,
The control device for the compressor according to claim 1, wherein the main relay contact and the auxiliary relay contact are turned on when the main relay contact is turned off and the overload relay is turned on. 3. The control unit, when the overload detector detects that the overload relay contact is turned off,
The control device for a compressor according to claim 1, wherein the main relay contact is turned off, the auxiliary relay contact is turned on, and the main relay contact is turned on when the overload relay is turned on. 4. An overload relay contact is connected to a common connection point of a main winding and an auxiliary winding of a motor for driving a compressor and is connected to one terminal of an AC power source, and is connected to the other terminal of the AC power source. Connect the main winding of the motor through a main relay contact, and connect an operating capacitor in parallel to the series circuit of the auxiliary relay contact and the starting capacitor between the main relay contact and the auxiliary winding of the motor. And a series-parallel circuit connected thereto, and an overload detector for detecting that the overload relay is OFF, and a signal from the overload detector is input to turn ON / OFF the contacts of the main relay and the auxiliary relay. A control unit for controlling is provided, and after the auxiliary relay contact is turned on, the main relay contact is turned on to start the motor, and then the auxiliary relay contact is turned off to switch the motor to an operating state. The controller receives the overload relay contact OFF detection signal from the overload detector and turns on the auxiliary relay contact to restart the compressor when the overload relay contact is turned on. Compressor control device characterized by. 5. The control unit, when the overload detector detects that the overload relay contact is turned off,
The control device for a compressor according to claim 4, wherein the main relay contact and the auxiliary relay contact are turned on when the main relay contact is turned off and the overload relay is turned on. 6. The control section, when the overload detector detects that the overload relay contact is turned off,
The controller of the compressor according to claim 4, wherein the main relay contact is turned off, the auxiliary relay contact is turned on, and the main relay contact is turned on when the overload relay is turned on.