JPS6212224Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to improvements in cooling devices mainly used for cooling refrigerators, particularly cooling devices having forced heating means.

Conventionally, this type of cooling device has been constructed as shown in FIG. 1 (also referred to in the cooling device of this invention) and FIG. 2. FIG. 1 is a diagram showing a schematic configuration thereof, and FIG. 2 is a diagram showing an electric circuit.

In both Figures 1 and 2, 1 is a compressor, 2 is a condenser, and 3 is an evaporator, and these are successively communicated by refrigerant piping (not shown) to form a refrigerant cycle. are doing. Further, 4 is a first blower, which is used to cool the condenser 2 with air.
The second blower 5 is configured to forcefully circulate the air inside the refrigerator 20 to the evaporator 3.

The condenser 2 is surrounded by a fan cover 6, and the evaporator 3 is surrounded by an evaporator fan cover 7 in the evaporator box 9. A drain pan 8 is disposed below the fan cover 7. Drain pan 8 is for receiving water falling from evaporator 3.

A temperature sensing element 13-1 of the internal temperature regulator 13 (FIG. 2) is arranged above the drain pan 8.
Further, a heater 12 is provided near the evaporator 3 to melt frost generated on the evaporator 3. The temperature of the evaporator 2 is detected by a temperature sensing element 14-1, and the temperature sensing element 14-1 is a temperature sensing element of the temperature switch 14.

Further, the compressor 1, condenser 2, and fan cover 6 are installed on a base plate 10, and this base plate 10
is attached to the outer surface of the refrigerator 20. Note that 11 is a guide plate that prevents the air blown out by the action of the second blower 5 from undergoing a short cycle.

Next, the electric circuit shown in FIG. 2 will be explained. In FIG. 2, a power supply voltage is applied between lines _L1 and _L2 , and a contact 13-2 of the internal temperature switch 13 is inserted into line _L2 .

A defrost timer 16 is connected between lines _L1 and _L2 . The defrost timer 16 has a contact 16-1, and when the cumulative energization time reaches 4 hours,
The contact 16-1 is configured to close, and the closing time of this contact 16-1 is 2 minutes, and after 2 minutes, it is configured to open again.

A series circuit between this contact 16-1, the heater 12, and the contact 14-2 of the internal temperature regulator 14 is connected to the line.
Connected between L ₁ and L ₂ . A contact 17-1 (normally open contact) of a relay 17 is connected in parallel to the contact 16-1, and the relay 17 is connected in parallel to the heater 12.

Further, a series circuit of a contact 17-2 (normally closed contact) of the relay 17 and a motor 5-1 of the second blower 5 is connected in parallel to the series circuit of the contact 17-1 and the relay 17.

Between lines L ₁ and L ₂ , contact 17-3 (normally closed contact) of relay 17 and motor 4 of first blower 4
-1 series circuit is connected, and this motor 4
A coil 15 of an electromagnetic switch is connected in parallel with -1. The electromagnetic switch is for opening and closing a power supply circuit (not shown) of the motor of the compressor 1, and when the coil 15 is excited, the compressor 1 is driven.

Next, the operation of the conventional cooling device will be explained. When the internal temperature, that is, the temperature of the air drawn into the evaporator 3, is higher than the temperature set in the internal temperature controller 13, the contact 13-2 is closed, the coil 15 is energized, and the compression Machine 1 is driven,
Cooling operation is performed.

At the same time, the defrost timer 16 adds up the cooling operation time. When this cumulative time reaches 4 hours,
Contact 16-1 is closed. During this cooling operation, the temperature of the evaporator 3 is low, so the contact 14-2 of the temperature switch 14 is closed. Therefore, contact 16-1
When the circuit is closed, the relay 17 is energized. When the relay 17 is excited, the contact 17-1 is closed and the contacts 17-2 and 17-3 are opened. As a result, the compressor 1, the first blower 4, and the second blower 5 are stopped, the heater 12 is energized, and the evaporator 3 is heated. This heating melts the frost in the evaporator 3. During this time, contact 16-1 is opened. When heating is continued to melt the frost and raise the temperature of the evaporator 3, the contact 14-2 opens. When the contact 14-2 is opened, the relay 17 becomes non-energized, the contact 17-1 is opened, and the contacts 17-2 and 17-3 are closed. As a result, the power supply to the heater 12 is cut off, and the compressor 1 and the first blower 4 are driven. On the other hand, the second blower 5 remains stopped because the contact 14-2 is open. By this cooling operation with the second blower 5 stopped, the air around the evaporator 3, that is, the air in the evaporator box 9, whose temperature and humidity have increased in the above-mentioned defrosting operation, is cooled and dehumidified. . If this state continues, the temperature sensing element 14-1 will detect a decrease in the temperature of the evaporator 3, and the contact 14-1 will detect the temperature drop in the evaporator 3.
2 is closed. When the contact 14-2 closes, the second blower 5 is driven and the original cooling operation is performed again.

As described above, in the conventional cooling device, the second blower 5 is not driven immediately after the defrosting is finished, but is driven after the air in the evaporator box 9 is cooled and dehumidified. The warm air generated during defrosting is not supplied, and the change in temperature inside the refrigerator is reduced accordingly. In addition, warm air may come into contact with the guide plate 11 and the ceiling of the refrigerator 20, which remain at low temperatures even after defrosting because they are in contact with the air inside the refrigerator, causing condensation that drips into the refrigerator and wets the stored items. The inconvenience is removed.

However, on the other hand, there were drawbacks as described below. In other words, when defrosting is completed and the cooling operation is started, the contact 13-2 is opened before the contact 14-2 is opened, and the compressor 1 is stopped, and the normal cooling operation is not performed. There was a drawback that there was no such thing.

This inconvenience is caused by, for example, the required temperature inside the warehouse being high.
Therefore, this occurs when the set temperature of the internal temperature regulator 13 is high. During cooling operation with the second blower 5 stopped after defrosting, the air that was in contact with the evaporator 3 is cooled, and the temperature sensing element 13 is cooled by natural convection.
-1, but as mentioned above, the set temperature of the internal temperature switch 13 is high, so the contact 13-2 opens before the evaporator 3 is sufficiently cooled and the contact 14-2 closes. Resulting in.

As a result, the compressor 1 stops, and the temperature of the evaporator 3 rises again. By this, contact 1
When 3-2 is closed, the cooling operation is performed again with the second blower 5 stopped, but due to the repetition of the above, the contact 13-2 is opened before the contact 14-2 is closed, and the compressor 1 stops. There is a drawback that this may be repeated and normal cooling operation may not be performed.

This idea was made in order to eliminate the above-mentioned drawbacks of the conventional technology.It prevents the second fan from being driven after a predetermined period of time has passed after the end of defrosting. It is an object of the present invention to provide a cooling device which can prevent dew condensation, and which can shift to normal cooling operation even if a contact of an internal temperature regulator is opened while a second blower is stopped.

Hereinafter, embodiments of the cooling device of this invention will be described based on the drawings. FIG. 3 is a circuit diagram showing an electric circuit in one embodiment. In FIG. 3, parts that are the same as those in FIGS. 1 and 2 are designated by the same reference numerals, and a description thereof will be omitted, and the description will mainly be given to the parts that are different from FIG. 2.

As is clear from comparing FIG. 3 with FIG. 2, in FIG. 3, a time relay 18 is connected in parallel to the motor 5-1 of the second fan 5, and A contact 18-1 is connected in parallel to a contact 13-2 of the internal temperature regulator 13.

This timed relay 18 makes contact 1 two minutes after the start of energization.
When the contact 8-1 is opened and the current is cut off, the contact 18-1 is immediately closed. The other configurations are the same as in FIG. 2.

Next, the operation of the cooling device of this invention constructed as above will be explained. The cooling operation is similar to the conventional cooling device described above.

Also, regarding the defrosting operation, when the cumulative time of the defrosting timer 16 reaches 4 hours, the contact 16-1 closes and the defrosting operation starts, the contact 17-2 opens, so the time relay 18 Since it is the same as the conventional cooling device described above except that the contact 18-1 is demagnetized and the contact 18-1 is closed, a description thereof will be omitted.

When the cumulative time of the defrost timer 16 reaches 4 hours and the contact 16-1 closes, the heater 12 heats up and the temperature of the evaporator 3 rises. When the temperature sensing element 14-1 detects and the contact 14-2 opens, the defrosting operation ends, the power supply to the motor 5-1 of the second blower 5 is cut off, and the second blower 5 is stopped. Shift to cooling operation.

In this state, the air surrounding the temperature sensing element 13-1 is cooled by natural convection, and even though the contact 13-2 is open, the contact 18-1 is closed.
The operations of the compressor 1 and the first blower 4 are connected.

By the cooling operation in this state, the air in the cooler box 9 is cooled and dehumidified. Furthermore, evaporator 3
When the temperature of decreases and contact 14-2 closes,
As the second blower 5 is driven, energization of the time relay 18 is started.

When the second blower 5 is driven, the air inside the refrigerator is sucked into the evaporator box 9. Before the start of the defrosting operation, the air in the refrigerator was at a temperature at which the contact 13-2 would close (if it were open, the defrost timer 16 would not integrate and defrost would not start. ) has become further heated during the defrosting operation, so the temperature sensing element 13-1 detects this and the contact 13-2 closes.

Note that in this cooling device, the contact 13-2
The time required for the circuit to close is within 2 minutes after the second blower 5 is driven.

Two minutes after the second blower 5 is driven, the contact 18-1 opens, but at this time, as mentioned above, the contact 13-2 is closed, so the operation of the refrigeration system is not affected. do not have.

When the normal cooling operation in which the second blower 5 is driven continues and the temperature inside the refrigerator drops to a predetermined temperature, the contact 13-2 opens;
Since the circuit 8-1 is open, the compressor 1 and the first blower 4 are stopped, and the time integration of the defrost timer 16 is interrupted.

When the temperature inside the refrigerator rises to the specified temperature,
The contact 13-2 is closed, the compressor 1 and the first blower 4 are driven again, and the time integration of the defrost timer 16 is restarted. By repeating this process, the temperature inside the refrigerator is maintained at a predetermined temperature.

As mentioned above, according to the cooling device of this invention,
Since the blower that forces air into the evaporator is not activated immediately after defrosting is completed, there is little change in the temperature inside the refrigerator, and dew condensation on the guide plate and ceiling of the refrigerator can be prevented.

Furthermore, even if the contacts of the internal temperature regulator are opened due to natural convection while the blower is stopped, normal cooling operation can be resumed without any problem, and its practical effects are extremely large.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the schematic configuration of a conventional cooling device and the cooling device of this invention, FIG. 2 is a circuit diagram showing an electric circuit in the conventional cooling device, and FIG. 3 is a circuit diagram of an embodiment of the cooling device of this invention. It is a diagram. 1... Compressor, 2... Condenser, 3... Evaporator,
4...First blower, 4-1, 5-1...Blower motor, 5...Second blower, 12...Heater, 13...Interior temperature controller, 13-2, 14-
2, 16-1, 17-1 to 17-3, 18-1...
. . . Contact, 14 . . . Temperature switch, 15 .

Claims (1)

[Scope of utility model registration request] A cooling device comprising: a temperature switch which operates by detecting the temperature of an evaporator or an evaporator outlet pipe; a blower which forcibly ventilates air to the evaporator; a temperature regulator which operates by detecting the temperature of the air forcibly ventilated to the evaporator; a first circuit which stops the blower when the temperature detected by the temperature switch is equal to or higher than a first predetermined temperature and drives the blower when the temperature detected by the temperature switch reaches a second predetermined temperature which is lower than the first predetermined temperature; and a second circuit which forms a circuit which operates and stops a compressor by the temperature switch only after a predetermined time has elapsed after the temperature detected by the temperature switch reaches the second predetermined temperature.