JPS6339833B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a freezer for freezing and preserving food.

Generally, when preserving food by freezing, cooling is performed to allow the food to pass through the maximum ice crystal formation zone (approximately 0°C to -7°C) in a short period of time. It is known that it can be stored at around ℃.

By the way, when rapidly freezing food, it is necessary to rapidly lower the cooling temperature to -40℃ or below, and for this reason, a quick freezer with a freezing capacity of -40℃ or less and a freezer with a freezing capacity of about -20℃ are required. A storage is required. However, this is not only uneconomical but also very troublesome as the food must be moved from the quick freezer to the frozen storage. Therefore, if a temperature controller is installed in a freezer with a freezing capacity of -40℃ or less, and the operation of this temperature controller is used to distinguish between quick freezing and cryopreservation, the above problems can be solved. However, the time required for freezing varies depending on the type of food, which makes it extremely difficult to accurately judge when to switch from quick freezing to cryopreservation. This creates a new problem of not being able to obtain high-quality frozen foods.

This invention was made in view of the above-mentioned circumstances, and its purpose is to provide an excellent product that can perform uniform and stable rapid freezing and cryopreservation and obtain high-quality frozen foods. The goal is to provide a freezer.

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

In FIGS. 1, 2, and 3, 1 is a main body, and an operation panel 2 is provided on the front of the main body 1, and a door 3 is pivotably supported so that the door 3 can be opened and closed. is detected by the door switch 4. Furthermore, a ventilation panel 5 is detachably provided at the lower front of the main body 1. A freezer compartment 6 whose periphery is thermally insulated is disposed within the main body 1 corresponding to the door 3. Inside this freezer compartment 6, there is a freezer compartment heat exchanger 7 which is a cooler, and freezer compartment fans 8a and 8 which circulate air in the freezer compartment 6 to this heat exchanger 7.
b, and a plurality of removable food storage shelves 9.

In addition, inside the main body 1 corresponding to the ventilation panel 5,
A freezer outdoor heat exchanger 1 is installed near the ventilation panel 5.
0, a freezer outdoor fan 11 that circulates outside air to the heat exchanger 10, a compressor 12, and an electrical parts box 13 are provided. Here, the compressor 12 and the heat exchangers 7 and 10 are connected in sequence with a four-way valve, various electromagnetic valves, a capillary tube, etc. (not shown) to form a heat pump type refrigeration cycle, and this refrigeration cycle and fan 8
A, 8b, and 11 constitute a refrigerator for cooling the inside of the freezer compartment 6. In this case, normally the heat exchanger 7 acts as an evaporator and the heat exchanger 10 acts as a condenser to cool the inside of the freezer compartment 6, but during defrosting operation the four-way valve switches and the heating cycle is formed, thereby defrosting the heat exchanger 7. By the way, as shown in FIG. 4, a gasket 3a for preventing cold air leakage is attached to the door 3, and a gasket receiver 6 corresponding to the gasket 3a is installed around the opening of the freezer compartment 6.
A is attached to the gasket receiver 6a, and an anti-dew heater 14 for preventing dew formation around the door 3 is installed inside the gasket receiver 6a. In this case, the anti-condensation heater 14 uses a 100V power supply instead of the 200V power supply used to drive the refrigerator, and even if electrical leakage occurs due to opening and closing of the door 3, a certain degree of safety is ensured. be done.

FIG. 5 shows the control circuit. 20 is a single-phase AC power supply, and this power supply 20 has power switches 21a, 21
The anti-condensation heater 14 is connected to the door switch (turned on when the door is opened) 4 via b.
A series circuit of the relay 22 and the relay 22 are connected.

On the other hand, 30 is a three-phase 200V AC power supply, and a compressor motor 12M is connected to this power supply 30 via switch contacts 44a, 44b, 44c and overload relays 31a, 31b, and fan motors 8aM, 8bM , 11M and a solenoid valve 35 are connected to each other. However, fan motor 8
Relay contacts 83a and 7 are in the energized paths of aM and 8bM.
1a and 22a are inserted and connected in series.

Power switches 41a and 41b are connected to the R and S phases of the power supply 30, respectively, and a high voltage switch 4 is connected between the power switches 41a and 41b.
2. An electromagnetic switch 44 is connected in series through a freezer compartment thermostat (closed at -20° C. or higher) 43, a relay contact 85a, and an overload relay contact 31a. Furthermore, a buzzer 45 is connected between the power switches 41a and 41b via a high voltage switch 42 to notify abnormally high pressure in the refrigeration cycle. Further, a quick freeze timer 50 is connected between the power switches 41a and 41b. This timer 5
0 is activated by turning on the power switches 41a and 41b, and closes the contact 50a for a time preset on the operation panel 2. thus,
When the contact 50a closes, the relay 51 and the delay timer 60 are energized, and the relay contact 5
By closing 1a, the thermostat 43 is short-circuited, and the contact 60a of the timer 60 is closed after a certain period of time, for example, 3 minutes.

Also, a delay timer 70 is connected between the power switches 41a and 41b via relay contacts 72b and 83b.
is connected. This timer 70 is activated when the power switches 41a and 41b are turned on, and switches the bidirectional contact 70a to the normally open side after a certain period of time, for example, 10 minutes. In this case, the relay 71 is energized for 10 minutes until the contact 70a is switched, and the relay contact 71a cuts off the energization to the fan motors 8aM and 8bM. Further, when the contact 70a is switched, the relay 72 is energized, and the relay contact 72a,
72b stops the operation of the timer 70 and forms a self-holding circuit for the relay 72.

Furthermore, between the power switches 41a and 41b,
A four-way valve 81, a defrosting heater 82, and a relay 83 are respectively connected via the timer contact 60a.
The defrosting heater 82 is mounted, for example, on the surface of the heat exchanger 7. In this way, the contact 60
When a is closed, the four-way valve 81 is switched and the refrigerant circulation direction of the refrigeration cycle becomes the defrosting cycle, that is, the heat exchanger 7 acts as a condenser, the anti-frost heater 82 generates heat, and the heat exchanger 7 Defrosting is performed. At this time, relay contact 83
A and 83b cut off power to the timer 70, relay 72, and fan motors 8aM and 8bM, respectively. Note that a relay 85 is connected in parallel to the relay 83 via a frost protection thermostat 84, and when the temperature inside the freezer compartment 6 is +10°C or higher during defrosting, the thermostat 84 closes and the relay 8
5 is now operational. This is based on the fact that when the temperature inside the freezer compartment 6 is +10°C or higher, there is not much frost on the heat exchanger 7, and the relay contact 85 is used to control the compressor motor 12 and fan motor 11M.
Cut off the power to the defrost heater 8, etc., and stop the defrosting operation.
It depends only on the heat generation of 2.

Further, a time switch 90 is connected between the power switches 41a and 41b via a relay contact 51b. This time switch 90 is a timer 9
1 and a timer contact 92. When energized through the relay contact 51b, the timer 91 is activated and the timer contact 92 is switched to the terminal 1L side for a fixed period of time periodically, for example, every four hours. Terminal 1L of time switch 90 is connected to a connection point between relay contact 60a, four-way valve 81, and defrosting heater 82. Further, a defrosting thermostat 99 that responds to the surface temperature of the heat exchanger 7 is additionally connected to the time switch 90.

In FIG. 5, L indicates indicator lamps, and various operating states are notified by these indicator lamps.

Next, the operation in the above configuration will be explained.

First, the food to be frozen is placed on the food shelf 9 in the freezer compartment 6, the door 3 is closed, and the timer 50 is set for a quick freezing time depending on the type of food. In this way, when the preparation for cryopreservation is completed, the power switches 21a, 21b and 41a,
When 41b is turned on, the anti-dew heater 14 is activated, and the timers 50, 60, and 70 are activated.
Therefore, by closing the relay contact 51a, the compressor 12, regardless of the thermostat 43 in the freezer compartment,
Freezer outdoor fan 11 and freezer indoor fan 8a,
8b is performed, and rapid connection operation begins. However, in this case, the timer 70 prohibits operation of the freezer compartment fans 8a and 8b for 10 minutes after the start, and the actual quick freezing operation starts when the heat exchanger 7 has sufficiently cooled down. Further, in this quick freezing operation, the timer 60 performs frost protection operation for a certain period of time 3 minutes after the start. This ensures that the cooling temperature change during the quick freezing operation, that is, the temperature change in the freezer compartment, is always uniform without being affected by frost formation on the heat exchanger 7.

After that, when the set time of the timer 50 has elapsed, the relay contact 51a opens, and the compressor 12, the freezer outdoor fan 11, and the freezer indoor fans 8a, 8
The operation of b is controlled by a freezer compartment thermostat 43. That is, the temperature inside the freezer compartment 6, which had been cooled to -40°C or lower, rises and is maintained at about -20°C, resulting in a cryopreservation operation. In this cryopreservation operation, the time switch 90 is activated by closing the relay contact 51b, and the defrosting operation is performed every four hours. When the defrosting operation is being performed, the operation of the freezer compartment fans 8a and 8b is stopped by opening the relay contact 83a. This is to prevent warm air from circulating inside the freezer compartment 6.

By the way, when the door 3 is opened during operation, the door switch 4 is turned on and the operation of the freezer compartment fans 8a, 8b is stopped by opening the relay contact 22a, thereby preventing cold air from blowing out. Further, when the refrigeration cycle becomes abnormally high pressure and the high pressure switch 42 is activated, the buzzer 45 emits an alarm sound.
Further, when the overload relay 31b is activated, the operation is stopped by the overload relay contact 31c, and the indicator lamp emits light to notify an abnormality.

Therefore, the time required for quick freezing is controlled by the quick freezing timer 50, and a defrosting operation is performed in advance before carrying out the quick freezing operation, so that stable quick freezing and cryopreservation can be achieved without any unevenness. It is possible to obtain high-quality frozen foods. In addition, regular defrosting operations during cryopreservation ensure good cooling at all times. During the defrosting operation, the operation of the freezer compartment fans 8a and 8b is stopped to prevent circulation of warm air within the freezer compartment 6, thereby improving cooling efficiency. Furthermore, since the anti-condensation heater 14 for the 100V power supply is adopted, even if electrical leakage occurs due to opening and closing of the door 3, it is safe to some extent.

In the above embodiment, the periodic defrosting operation based on the time switch 90 is performed for a certain period of time by the timer operation, but a defrosting thermostat 99 is wired inside the time switch 90, and thereby The anti-frost operation time may be controlled by the surface temperature of the heat exchanger 7. Also,
The operating temperatures of the freezer compartment thermostat 43 and the defrosting thermostats 84 and 99 do not need to be constant, and can be adjusted as appropriate, for example, by operating the operating panel 2.

In addition, the present invention is not limited to the above-mentioned embodiments, and various modifications can be made without changing the gist.

As described above, according to the present invention, there is provided a refrigeration cycle in which a freezer compartment, a compressor, a four-way valve, a freezer compartment heat exchanger, a freezer compartment outdoor heat exchanger, etc. are connected in sequence, and a freezer compartment heat exchanger. a refrigerator comprising a freezer compartment fan that circulates air in the freezer compartment and having a freezing capacity capable of responding to rapid freezing;
Means for performing quick freezing operation by continuous operation of the compressor for a set time, and after this quick freezing operation,
a thermostat that controls the compressor according to the temperature in the freezing chamber to perform cryopreservation operation;
means for pre-defrosting the freezer indoor heat exchanger for a certain period of time during the quick freezing operation; means for periodically performing a defrosting operation for the freezer indoor heat exchanger during the cryopreservation operation; To provide an excellent freezer that can perform uniform and stable rapid freezing and cryopreservation, and can obtain high-quality frozen foods, by providing a means for stopping the operation of the fan in the freezer compartment during frost operation. can.

[Brief explanation of the drawing]

The drawings show one embodiment of the invention.
2 and 2 are external perspective views, FIG. 3 is a block diagram schematically showing the internal mechanism, FIG. 4 is a block diagram showing the main parts of the opening and door of the freezer compartment, and FIG. 5 is a block diagram of the control circuit. FIG. 1...Main unit, 3...Door, 6...Freezer compartment, 7...
...Heat exchanger in the freezer, 8a, 8b... Fan in the freezer, 12... Compressor, 43... Thermostat in the freezer, 50... Timer for quick freezing.

Claims (1)

[Claims] 1. A refrigeration cycle in which a freezer compartment is connected to a compressor, a four-way valve, a heat exchanger inside the freezer compartment, a heat exchanger outside the freezer compartment, etc., and a refrigeration system in which air inside the freezer compartment is circulated to the heat exchanger inside the freezer compartment. a refrigerator comprising an indoor fan and having a freezing capacity corresponding to quick freezing; a means for performing quick freezing operation for a set time by continuous operation of the compressor; a thermostat that controls the compressor to perform a cryopreservation operation; a means for preliminarily performing a defrosting operation on the heat exchanger in the freezer compartment for a certain period of time during the quick freezing operation; A freezer comprising means for periodically performing defrosting operations on an exchanger, and means for stopping operation of the freezer compartment fan during these defrosting operations.