JPS6138065Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a refrigerator having an evaporator for indirect cooling as well as an evaporator for direct cooling.

Traditionally, refrigerators with an evaporator for indirect cooling have been fan-cooled, in which the evaporator cools the air inside the refrigerator that is circulated by a fan, thereby indirectly cooling stored items. It is well known. However, although this type of refrigerator has the advantage of not forming frost inside the refrigerator, it has the disadvantage that it takes a long time to make ice and freeze stored products. An evaporator for direct cooling is installed in the chamber from which air is blown out, and ice making trays and foods to be frozen are placed on the evaporator and brought into contact with each other to make or freeze ice in a short period of time. We are thinking about what can be done. However, in this case, when the cooling operation is started after defrosting the indirect cooling evaporator, the fan blows out warm air from the indirect cooling evaporator part, which has risen in temperature due to defrosting, into the refrigerator. As a result, the temperature of the direct cooling evaporator increases, resulting in a disadvantage that the desired rapid freezing cannot be carried out.

The present invention has been devised to eliminate the above-mentioned drawbacks, and one embodiment thereof will be described below with reference to FIGS. 1 to 5. First, in Fig. 1, 1 is the main body of the refrigerator, 2 is a lower door pivoted to open and close the lower half of the front opening, and 3 is an upper door pivoted to open and close the remaining upper part. 4 and 5 are the handles of both doors 2 and 3. On the other hand, reference numeral 6 denotes a partition plate disposed deep inside the storage body 1, with an air inlet 7 formed in the lower part and an air outlet 8 formed in the upper part. ing. Reference numeral 9 denotes a duct portion formed in the inner part of the refrigerator main body 1 by the partition plate 6, in which an evaporator 10 for indirect cooling is disposed, and above the duct portion, air is connected to the interior of the refrigerator from the air outlet 8. A fan 11 for circulating air inside the refrigerator is disposed facing the refrigerator. Then 1
Reference numeral 2 denotes a direct cooling evaporator, which is not shown in detail, but is made up of, for example, a heat-conducting sheet member with refrigerant paths arranged in a meandering manner. For example, they are arranged in a shelf-like manner in two stages at the lower front part. or,
Here, FIG. 2 shows the entire structure of the refrigeration cycle 13, and in the cycle 13, 14 is the storage main body 1.
This is a compressor installed in the outer lower part (machine room) of the engine, to which a capacitor 15 is connected.
7. The direct cooling evaporator 12 and the indirect cooling evaporator 10 are connected in sequence and further connected to the compressor 14, and a capillary is connected in parallel to the series path from the solenoid valve 16 to the direct cooling evaporator 12. The tube 18 is connected. Further, in FIG. 3 showing the entire electric circuit, 14m is a drive motor for the compressor 14, 15m is a cooling fan motor for the condenser 15, 11m is a drive motor for the refrigerator air circulation fan 11, Reference numeral 19 denotes a temperature-sensitive switch. In particular, this temperature-sensitive switch 19 opens and closes by sensing the temperature of the direct cooling evaporator 12, and when the temperature of the direct cooling evaporator 12 is, for example, -10
If the temperature is below [℃], close +3 to 4 [℃]
When this is the case, it is disposed in close contact with at least one side of the direct cooling evaporator 12 so as to be open. Further, 20 is a defrosting heater that defrosts the indirect cooling evaporator 10;
21 is a bimetallic detection switch for detecting the end of defrosting, and 22 is a timer motor 2.
2m and a timer switch 22s which is closed once every fixed period of time, for example every 24 hours; 23 is a quick freezing switch;
4 is a relay coil 24c and first to third relay switches 24s ₁ to 2 which are respectively opened and closed by the relay coil 24c.
25 is a _second relay consisting of a relay coil 25c and first and second relay switches 25s ₁ and 25s ₂ which are respectively opened and closed by the relay coil 25c. 26 is a relay that controls the temperature inside the refrigerator. It is a control switch that opens and closes by sensing, and 27 is a power source, to which each of the above-mentioned components is connected together with the electromagnetic valve 16 as shown.

Next, to describe the operation of the above-mentioned structure, first, during normal cooling operation, each switch is in the state shown in Figure 3. Therefore, at this time, when the temperature inside the refrigerator exceeds the set temperature, the switches are closed. Control switch 26 that opens when the temperature drops below the set temperature.
The second relay 25 relay switch 25s ₁
The supply of electricity to the drive motor 14m of the compressor 14 and the cooling fan motor 15m of the condenser 15 is controlled intermittently through the normally closed contacts ob and b. Therefore, compressor 14
The drive motor 14m drives the compressor 14 by applying electricity, and the driven compressor 14 compresses and delivers refrigerant (not shown). The refrigerant thus pumped from the compressor 14 is then sent from the condenser 15, in this case, through the capillary tube 18, to the indirect cooling evaporator 10, where it evaporates. 10 is cooled at a temperature that is, for example, 5 degrees or more lower than the temperature at which the direct cooling evaporator 12 is cooled as described below. Also, at this time, the direct cooling evaporator 12 is -10
If the temperature is below [°C], the motor 11m for driving the refrigerator air circulation fan 11 is energized through the temperature-sensitive switch 19, which senses the temperature and closes the switch. fan 1
1 is driven, and the driven fan 11 circulates the air in the refrigerator by sucking the air into the duct part 9 from the air inlet 7 and then blowing it out into the refrigerator from the air outlet 8.
In the middle of the process, the air sucked into the duct part 9 is cooled by the indirect cooling evaporator 10 and becomes cold air, and therefore the cold air is blown out from the air outlet 8. This indirectly cools the stored items in the warehouse.

Regarding the above, when the ice cube tray and the frozen food are placed on the direct cooling evaporator 12 and the quick freezing switch 23 is closed for quick freezing, each switch is in the state shown in FIG. 4. present That is,
At this time, by closing the quick freezing switch 23, the solenoid valve 16 is energized through the second relay switch 25s ₂ (normally closed) of the second relay 25. It is opened and the refrigerant flows directly through the capillary tube 17 to the cooling evaporator 12 and is evaporated. Therefore, the above-mentioned ice trays and foods to be frozen that are placed on and in contact with the direct cooling evaporator 112 are directly cooled by the direct cooling evaporator 12, and so-called quick freezing is performed. On the other hand, at this time, the relay coil 24c of the first relay 24 is energized together with the above-mentioned solenoid valve 16, and as a result, the first relay switch 24s ₁ and the second relay switch 2
4s ₂ (both normally open) are respectively closed, and the third relay switch 24s ₃ (normally closed) is opened. Now, during such rapid freezing, assuming that the defrosting time has now been reached, the timer switch 2 of the defrosting timer 22 is turned on.
2s is closed, this causes the second relay 25
The relay coil 25c is energized and the first relay switch _25s1 changes from the state in which the contact pieces ob and b are closed to the state in which the contact pieces o and a are closed. 14m, the fan motor 15m for cooling the condenser, and the fan motor 11m for internal air circulation are cut off, and the defrosting heater 20 is turned off.
Switch the state so that the current is energized, and also change the second relay switch _25s2 from the previously closed state to the open state,
That is, the state is changed to such a state that current is cut off to the solenoid valve 16 and the relay coil 24c of the first relay 24, but for the former, the second relay 24 turns off the second relay switch _24s2. close it,
Furthermore, since the third relay switch _24s3 is opened, the compressor driving motor 14m continues to be energized, while the defrosting heater 20 continues to be energized, and the latter After all, the second relay 24 is the first relay switch 24s ₁
is closed, the electromagnetic valve 16 and the relay coil 24c of the first relay 24 continue to be energized, thus continuing to maintain the rapid freezing operating state. Note that when the quick freezing switch 23 is opened after completing the desired quick freezing, the electromagnetic valve 16 is cut off and at the same time the relay coil 24c of the first relay 24 is cut off. The relay switch 24s ₁ and the second relay switch 24s ₂ are each in the open state, and the third relay switch 24
_s3 returns to the closed state. Therefore, later, as shown in FIG. 5, it is necessary to close the contacts o and a of the first relay switch _25s1 of the second relay 25 and open the second relay switch _25s2 . Only the frost operation state remains, and in this state, electricity is turned off to the compressor drive motor 14m, etc., and the defrost heater 20 is energized to generate heat and defrost the indirect cooling evaporator 10. .

As described above, when defrosting the indirect cooling evaporator 10, the second relay switch _25s2 of the second relay 25 is in the open state, and therefore, at this time, the quick freezing switch is 2
3 is closed to perform the previous rapid freezing, the electromagnetic valve 16 and the relay coil 24c of the first relay 24 are closed by opening the second relay switch _25s2 of the second relay 25. Since no electricity is supplied, the quick freezing operation is not performed, and the defrosting operation continues without being interrupted by the quick freezing operation. Then, when the defrosting of the indirect cooling evaporator 10 is completed, the detection switch 21 detects this and opens.
This causes the relay coil 25 of the second relay 25 to
c is cut off, the first relay switch _25s1 is returned to the closed state between the contact pieces ob, and at the same time the second relay switch _25s2 is returned to the closed state. Therefore, if the quick freezing switch 23 is still in the closed state, the electromagnetic valve 16 and the relay coil 24c of the first relay 24 are energized, and the quick freezing operation is then carried out in the same manner as described above. It will be done. Therefore, if such a quick freezing operation is performed, the temperature of the direct cooling evaporator 12 will drop rapidly, and this temperature drop (not necessarily rapid) will cause the temperature of the direct cooling evaporator 12 to - Ten
[°C] or below, the temperature-sensitive switch 19, which had been open due to the previous defrosting operation, will also close upon sensing the temperature of the direct cooling evaporator 12 that has reached -10 [°C] or below. Therefore, the drive motor 11m of the fan 11 for internal air circulation is energized, and the fan 11 for internal air circulation is thereby energized.
is driven. That is, in this embodiment, the temperature of the direct cooling evaporator 12 after defrosting is -10
The internal air circulation fan 11 is activated after waiting for the temperature to drop below [°C], unlike the conventional system, which operates at the same time as the defrosting operation is completed. The remaining warm air is not blown directly to the cooling evaporator 12, and the direct cooling evaporator 12
Since the evaporator itself has already been cooled down to -10°C, the temperature rise in the direct cooling evaporator 12 is suppressed, and thus the desired rapid freezing can be carried out.

Incidentally, FIG. 6 shows a different embodiment of the present invention, in which, in addition to the configuration of the above-described embodiment, a relay coil 28c and first and second relay switches 28s ₁ and 28s ₂ opened and closed by the relay coil 28c are shown. and a control switch heater 26h that forcibly heats the control switch 26.
and a new defrosting timer 22.
This embodiment differs from the previous embodiment in that it is connected as shown in the figure between the defrosting heater 20 and the defrosting heater 20. According to this different embodiment, when the timer switch 22s of the defrosting timer 22 during defrosting is closed, the relay coil 28c of the third relay 28 and the control switch heater 26h are energized. Therefore, the first relay switch 2
8s ₁ and second relay switch 28s ₂ (both permanently open)
is closed, and the control switch 26 is forcibly heated and kept in the closed state. When the first relay switch 28s ₁ is closed, the electromagnetic valve 16 and the relay coil 24c of the first relay 24 are energized, so that the above-mentioned control In addition to maintaining the switch 26 closed, the direct cooling evaporator 1
2. Cooling So to speak, preliminary cooling is performed. In this embodiment, the temperature rise in the direct cooling evaporator 12 due to heat conduction from the indirect cooling evaporator 10 or convection of warm air during defrosting, as well as after the completion of defrosting, is caused by the direct cooling evaporator 12. This can be prevented by pre-cooling the cooling evaporator 12, and therefore the effect is greater than that described above. When the second relay switch _28s2 is closed, the relay coil 25c of the second relay 25 is energized, and the first relay switch _25s1 of the second relay 25 is connected. Switching from the state where the contact piece o and b is closed to the state where the contact piece o and a is closed, and
The second relay switch _25s2 is opened. Then, when the previous timer switch 22s is opened, the relay coil 28c of the third relay 28 and the control switch heater 26h are cut off, so the first relay switch 28s ₁ and the second relay switch 28s ₂ are Both return to the open state, and the control switch 26 is released from the forced heating state. When the first relay switch _28s1 is opened, the electromagnetic valve 16 and the relay coil 24c of the first relay 24 are cut off, so that the preliminary cooling of the direct cooling evaporator 12 is completed. , instead of the above relay coil 2
Third relay switch 24s ₃ based on power failure of 4c
As a result of the return to the closed state, the first relay switch _25s1 of the second relay 25 maintains the closed state (self-maintenance) between the contacts o and a, and the defrosting heater 20 is energized to indirectly Defrosting of the cooling evaporator 10 is started.

Note that the present invention is not necessarily limited to the circuit configurations of the above embodiments. Furthermore, the temperature at which the temperature-sensitive switch opens and closes is not limited to the values in the above embodiments.

As is clear from the above description, according to the present invention,
In a refrigerator that has an indirect cooling evaporator that indirectly cools stored items by cooling internal air circulated by a fan, and a direct cooling evaporator that directly and rapidly cools stored items,
This has the valuable effect of preventing the warm air generated by defrosting the indirect cooling evaporator from being blown onto the direct cooling evaporator, thereby allowing desired rapid freezing to be carried out without being adversely affected by it. be.

[Brief explanation of the drawing]

1 to 5 show an embodiment of the present invention,
Figure 1 is a longitudinal side view of the entire refrigerator, Figure 2 is a schematic configuration diagram of the refrigeration cycle, Figure 3 is an electrical circuit diagram, and Figures 4 and 5 are electrical diagrams during quick freezing operation and defrosting operation, respectively. 6 is a circuit diagram, and FIG. 6 is a diagram corresponding to FIG. 3 showing a different embodiment of the present invention. In the figure, 1 is the refrigerator main body, 10 is an evaporator for indirect cooling, 11 is a fan for circulating air in the refrigerator, 12 is an evaporator for direct cooling, 14 is a compressor, 1
6 is a solenoid valve, 19 is a temperature-sensitive switch, 20 is a defrosting heater, 22 is a defrosting timer, 23 is a quick freezing switch, 24 is a first relay, 25 is a second relay, 28 is a third relay. It's a relay.

Claims (1)

[Scope of utility model registration request] It is equipped with a fan for circulating indoor air, an indirect cooling evaporator for cooling the circulating air, and a direct cooling evaporator disposed inside the warehouse from which the cooling air is blown out, and also for defrosting the indirect cooling evaporator. The fan is equipped with a defrosting heater that senses the temperature of the direct cooling evaporator and shuts off the fan when the temperature is above a predetermined value. refrigerator.