JPS6216611Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a refrigerator with two coolers.

Conventionally, this type of refrigerator has been equipped with two coolers, one for the freezer compartment and one for the refrigerator compartment, and when the freezing room temperature exceeds a predetermined level, a compressor is driven to flow refrigerant to both coolers. state,
As a result, when the refrigerator compartment is cooled to a predetermined temperature or lower, a configuration is provided in which the operating state is switched to a second operating state in which refrigerant is supplied only to the freezer compartment cooler. In the above configuration, in the second operating state, the refrigerant absorbs heat only in the freezer compartment cooler, so the degree of gasification and expansion of the refrigerant is small, and in the first operating state, the refrigerant absorbs heat in both coolers. The load on the compressor is reduced compared to the current state, and the motor rotates with a light load. However, as is well known, motors have a characteristic that their efficiency decreases when they rotate below the rated load, so with the above configuration, efficiency decreases in the second operating state in which the motor rotates under a light load, and more power is wasted than necessary. I had a problem with it.

Therefore, the purpose of the present invention is to improve the efficiency of the motor during light load rotation by lowering the voltage applied to the motor in the second operating state where the motor is under a light load than the rated voltage. The object of the present invention is to provide a refrigerator that can reduce power consumption.

An embodiment of the present invention will be described above with reference to the drawings.

In FIG. 1, reference numeral 1 denotes a heat insulating box of a two-temperature type refrigerator, inside which a freezing compartment 2 and a refrigerating compartment 3 are formed above and below. The freezer compartment 2 is constituted by a box-shaped freezer compartment cooler 4 which is a first cooler, and the refrigerator compartment 3 is constructed by disposing a refrigerator compartment cooler 6 which is a second cooler in an inner box 5. has been done. 7 is a compressor disposed at the rear of the bottom of the heat insulating box 1, 8 is a door for the freezer compartment, and 9 is a door for the refrigerator compartment.

FIG. 2 shows a cooling cycle, in which 10 is a condenser that liquefies the refrigerant sent from the compressor 7, 11 is a main capillary tube, 12 is an auxiliary capillary tube, and 13
1 is a solenoid valve, and 14 is a bypass capillary tube, which are connected as shown in the figure with the respective coolers 4 and 6 for the freezer compartment and refrigerator compartment. Here, the solenoid valve 13 is configured to close when the power is cut off and open when the power is turned on, and when the solenoid valve 13 is closed, the refrigerant flowing from the compressor 7 side flows into both the coolers 6 and 4 for the refrigerator compartment and the freezer compartment. There is a "first operating state" in which the refrigerant is supplied to both in turn, and a "second operating state" in which refrigerant is supplied only to the freezer compartment cooler 4 via the solenoid valve 13 and the side capillary tube 14 in order when the refrigerant is opened. ”. Now, in such a cooling cycle, the motor 7 of the compressor 7
The motor 7a is constituted by, for example, a single-phase induction motor with a rated voltage of 100V, and the electric circuit configuration for controlling the operation of this motor 7a is as shown in FIG. That is, in FIG. 3, reference numeral 15 denotes a temperature switch for the refrigerator compartment, which has a well-known configuration and opens when the temperature inside the refrigerator compartment 3 is detected and the temperature exceeds a set temperature, and 16 denotes a cooler for the freezer compartment 4 and a cooler for the refrigerator compartment. Connecting pipe 1 between 6 and
7 (see Figure 2), a connecting pipe heater, 18
is a relay having a changeover switch 18A forming a changeover circuit A, and this relay A has its excitation coil 1
When the switch 9 is in a power-off state, it returns to close the contacts (a-b) of the switch 18A, and when the excitation coil 19 is energized, it operates and switches the switch 1.
It is designed to close the contact piece (a-c) of 8A. 20 is, for example, a single-phase 100V power supply, and bus bars 20a and 20b are connected to both terminals of the power supply.
In between, there is a temperature switch 15 for the refrigerator compartment, and the solenoid valve 1.
3 and the parallel circuit of connecting pipe heater 16 and relay 1
Eight excitation coils 19 are connected in series. Further, 21 is a temperature switch for the freezer compartment of a well-known configuration that detects the temperature in the freezer compartment 2 and closes when the temperature is higher than a set temperature, and 22 is a phase control circuit which is a voltage control circuit. This is a well-known configuration in which the phase is controlled by triggering the triax by a diagonal turned on by a time constant circuit, and it is set to control the power supply voltage, which has a rated voltage of 100V, to approximately 80V. In the freezer temperature switch 21, one terminal is connected to the bus bar 20a, and the other terminal is branched into two,
Its first branch end is directly connected to one fixed contact piece b of the changeover switch 18A, and its second branch end is connected to the changeover switch 1 through the phase control circuit 22 in series.
It is connected to the other fixed contact piece c of 8A. Then, the movable contact piece a of the changeover switch 18A and the bus bar 20
A motor 7a of the compressor 7 is connected between the motor 7a and the compressor 7b.

Next, the operation of the above configuration will be explained. First, when both the freezer compartment 2 and the refrigerator compartment 3 are at or above the set temperature, the freezer compartment temperature switch 21 closes;
The temperature switch 15 for the refrigerator compartment is open, and when the temperature switch 15 for the refrigerator compartment is opened, the relay 18 is reset and the contact piece (a-
b) The contact piece (a-c) is closed and the contact piece (a-c) is open. Therefore, the contact piece (a-
c) The phase control circuit 22 is disabled by opening the gap between A voltage of 100V is applied, and the compressor 7 is driven. At this time, the electromagnetic valve 13 is cut off by the opening of the temperature switch 15 for the refrigerator compartment and is in a closed state. The system enters the "first operating state" in which the liquids are sequentially supplied, and both the interiors of the freezer compartment 2 and the refrigerator compartment 3 are cooled. In this "first operating state", the refrigerant absorbs heat in both the coolers 4 and 6, so the degree of gasification and expansion is large, and therefore the compressor 7 that compresses the gas refrigerant has a relatively large Although a load is applied to the motor 7a of the compressor 7, the rated voltage
Since 100V is applied, the torque is sufficiently large and the compressor 7 can be sufficiently driven.
As a result of such cooling operation, the temperature inside the refrigerator compartment 3 decreases and the temperature switch 15 for the refrigerator compartment closes, the solenoid valve 13 is opened and switched to the "second operating state", and therefore the compressor 7 side The refrigerant is supplied only to the freezer compartment cooler 4 to continue cooling the freezer compartment 2. When switching to this "second operating state", the refrigerant absorbs heat only in the freezer compartment cooler 4, so the degree of gasification and expansion becomes relatively small, and the gas refrigerant is easily transferred to the compressor 7. Motor 7
The load on a also decreases. In this embodiment, at the same time as the switching to the "second operating state", the excitation coil 19 of the relay 18 is energized and operated to close the contacts (a-c) of the changeover switch 18A. , the phase control circuit 22 is enabled and a voltage lower than the rated voltage (approximately 80V) is applied to the motor 7a of the compressor 7. As is clear from the torque-efficiency curve in Figure 4, the efficiency of the motor 7a improves under light loads by lowering the applied voltage (the solid line in the figure indicates when the rated voltage is applied, and the broken line indicates when approximately 80V is applied). ),
Efficiency in the "second operating state" is improved and operation can be performed with lower power consumption. When the temperature inside the freezer compartment 2 decreases due to this cooling operation and the freezer temperature switch 21 is opened, the motor 7a of the compressor 7 is cut off and the cooling operation is stopped, and the same operation follows. is repeated.

As described above, the present invention includes first and second coolers, and has a first operating state in which refrigerant from the compressor side flows into both the first and second coolers and a second operating state in which the refrigerant from the compressor side flows into both the first and second coolers. In the second operating state, the flow is switched to only one of the two coolers, and in the second operating state, a voltage lower than the rated voltage is applied to the compressor motor. However, as a result, it is possible to provide a refrigerator that can improve the efficiency of the motor in the second operating state in which it rotates under a light load, thereby reducing the overall power consumption.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, in which Fig. 1 is an overall longitudinal sectional view, Fig. 2 is a configuration diagram of a cooling cycle, Fig. 3 is an overall schematic electrical circuit diagram, and Fig. 4 is a diagram showing the motor torque. - Efficiency curve diagram. In the figure, 4 is a freezer compartment cooler (first cooler);
6 is a refrigerator compartment cooler (second cooler), 7 is a compressor, 7a is a motor, 18 is a relay, 22 is a phase control circuit (voltage control circuit), and A is a switching circuit.

Claims (1)

[Scope of utility model registration request] A first operating state comprising a first and second cooler, in which refrigerant from the compressor side flows into both the first and second coolers; and either one of the first and second coolers. A voltage control circuit that applies a voltage lower than the rated voltage to the motor of the compressor; and a voltage control circuit that is effective in the second operating state. and a switching circuit that applies a voltage lower than the rated voltage to the motor of the compressor, disables the voltage control circuit in the first operating state, and applies the rated voltage to the motor of the compressor. Refrigerator.