JPS6014080A - Defroster - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a defrosting device for refrigerators, freezers, chicor cases, and heat pump air conditioners.

Structure of a conventional example and its problems FIG. 1 shows a conventional defrosting device for a refrigerator. Below - The configuration of this conventional example will be explained with reference to FIG. 1. 01 is an internal temperature detector, 2 is a cooler temperature detector, and 3 is a temperature detector based on the signals of these internal temperature detector 1 and cooler temperature detector 2. A control circuit that controls the compressor/saucer drive device 6, the blower drive device 7, and the defrost heater drive device 8; 4 is a defrost timer;
5 is a compressor drive integration timer that integrates the compressor drive time.

Next, the operation of the conventional example will be explained. In FIG. 1, a control command is sent to the compressor drive device 6 and the blower drive device 7 to operate the cooling cycle of the refrigerator so that the temperature detected by the internal temperature detector 1 reaches the set temperature set by the control circuit 3. . On the other hand, the compressor drive integration timer 6 integrates the drive time of the compressor, and gives a command to the control circuit 3 and the defrosting timer 4 when the time has been integrated for a certain period of time (for example, set to 10 to 12 hours).

In response to this command, the control circuit 3 stops the compressor, stops the blower, and at the same time sends a command to the defrosting heater drive device 8 to energize the defrosting heater.At the same time, the defrosting timer 4 also starts operating. Enter the tb defrost cycle. During this time, the control circuit 3 waits for a signal from the cooler temperature detector 2. When the cooler is completely defrosted, the temperature of the cooler rises, and when the temperature reaches a certain level, a signal is sent from the cooler temperature detector 2. is served. This signal causes the control circuit 3 to switch the refrigerator cycle from the defrosting cycle to the original cooling cycle. When no signal is output from the cooler temperature detector 2, the defrosting timer 4 generates a signal after a certain period of time and sends a defrosting completion signal to the control circuit 3. Of course, there are some models in which either the cooler temperature detector 2 or the defrost timer 4 is omitted. However, in the conventional example, defrosting of the cooler is started based on the cumulative value of the compressor drive time, and the cooling is actually performed. It is unclear whether cooling efficiency has decreased due to frost adhering to the cooler. Therefore, if the door is opened and closed frequently or the humidity outside the refrigerator is high, frost will form on the cooler in a short period of time. On the other hand, if the door is opened and closed less often or if the air outside the refrigerator is dry, the time required for frost to form on the cooler will be longer. In these cases as well, the conventional example always defrosts for a certain cumulative time even when it is unnecessary, which has the disadvantage of reducing cooling efficiency and increasing power consumption.

OBJECTS OF THE INVENTION The present invention eliminates the conventional drawback of running a defrost cycle even when it is not needed, and the present invention eliminates the drawback of the prior art of running a defrost cycle even when it is not needed. This provides so-called demand defrost, which indirectly detects the temperature by monitoring and switches the cooling cycle to the defrosting cycle only when necessary.

Structure of the Invention In order to achieve this object, the present invention provides an internal temperature detector for detecting the temperature of air that is circulated in the refrigerator by a blower and cooled by a cooler, a compressor drive device, and a defrosting heater. a drive device, a blower, a blower drive device that drives the blower, and a current detector that detects the current of the blower;
a determination circuit that determines the amount of current detected by the current detector and issues a signal for a certain period of time; a determination circuit that determines the amount of current detected by the current detector; and a determination circuit that determines the amount of current detected by the current detector; A control circuit is provided to control the drive device and the blower drive device, respectively.

With this configuration, when the current value detected by the current detector determines the frosting state by the determination circuit, a command is sent to the control circuit, the defrost heater removes snow from the cooler, and the defrost is required. Only then can the cooling cycle be switched to defrost control to defrost, increasing cooling efficiency and saving power.

Description of examples Hereinafter, FIG. 2 of the drawings will be described with reference to one embodiment of the present invention.

This will be explained along with FIG.

FIG. 2 shows a refrigerator-freezer having a freezer compartment 9 and a refrigerator compartment 1o, and the refrigerant compressed by a compressor 11 passes through a radiator (not shown) and a capillary tube (not shown) to cool a cooler 12. . On the other hand, the blower 13 guides cooled air to the freezer compartment 9 and the refrigerator compartment 2, respectively. A damper thermometer 14 detects the temperature of the refrigerator compartment and controls the gap of the damper to control the inflow of cooling air into the refrigerator compartment 2. 15 indicates a heater attached to the cooler 12,
When frost forms on the cooler 12, the heater is energized to defrost. The air in the freezer compartment 9 flows as shown by the solid line arrow, and the cooled air in the refrigerator compartment 10 flows as shown in the dotted line arrow.

When the relatively warm air from both sides passes through the cooler 12, it is cooled to approximately the temperature of the cooler, and most of it is guided to the freezer compartment 9 and a part to the refrigerator compartment 10 by the blower 13. In this case, all the air passing through the cooler 12 is routed through the blower 13, so the air volume when there is frost on the cooler 12 is:
The air volume will be lower than when there is no frost at all. The present invention focuses on this point and detects the state of frost on the cooler 12. Generally, when the air volume is reduced, the current of the blower 13 becomes smaller than when the air volume is large.This is because the amount of work of the air blower 13 is reduced. Reference numeral 16 denotes an internal temperature detector for detecting the temperature inside the refrigerator, and a detection signal is input to a control circuit 17. 18, 19, and 20 respectively indicate a compressor drive device, a defrost heater drive device, and a blower drive device;
All are driven by the control circuit 17. In addition, the sending machine 13
is driven by the blower drive circuit 2o. A current detector 21 detects the current flowing through the blower 13. 2
Reference numeral 2 denotes a determination circuit that notifies the control circuit 17 of a signal for a certain period of time if the value output from the current detector 21 is greater than or equal to a certain value.

In a normal cooling cycle, the internal temperature detected by the internal temperature detector 1 is compared with the set value of the control circuit 17, and if it is higher than the set value, a command is sent to the compressor drive device 18 and the blower drive device 20 to start cooling operation. When the internal temperature reaches the set value, the compressor drive device 1
Temperature control is carried out by stopping the command to 8 and stopping the operation of the compressor. During this cooling operation, air or moisture containing humidity is brought into the refrigerator by opening and closing the door of the refrigerator or by putting new food into the refrigerator. When this moisture in the air passes through the cooler 12 shown in FIG. 3, it becomes frost and adheres firmly to the fins of the cooler. As the amount of hard-on frost increases, the amount of air passing through the cooler 12 decreases. When the air volume decreases, the load on the blower 13 decreases, so the current value detected by the current detector 6 in FIG. 3 decreases. This current value is level-compared by the determination circuit 221C in FIG. 2, and when it changes to a certain constant value, the determination circuit 22 issues a command to the control circuit 17 for a certain period of time. The control circuit 17 receives this command and starts the compressor drive device 1.
8 to stop the compressor, send a command to the defrost heater drive device 19, energize the defrost heater,
Then, a command is sent to the blower drive device 2° to stop the blower. In other words, it enters the defrost cycle. The defrosting cycle is carried out for a certain period of time predetermined by the determination circuit 22. Of course, the defrosting cycle can also be canceled by separately installing a temperature sensor in the cooler 12 and notifying the control circuit 17 that the temperature of the cooler 12 has exceeded a certain value. Note that the blower 13 shown in FIG. 3 may be an AC motor or a DC motor. Further, the current detector 6 in FIG. 3 may be a combination of a current transformer and an electronic circuit, a means for detecting by inserting a resistor, a means for detecting by a light emitting element, or a means for detecting by a combination of these.

Further, the structure is such that all the circulating air passing through the cooler 12 shown in FIG. 2 passes through the blower 13 in an efficient manner.

Although this embodiment shows an example of a refrigerator, the present invention may also be applied to a freezer, a showcase, or a heat pump air conditioner that requires a defrosting device. Also, in the block diagram of Figure 3,
Any block can be constructed using a micro combi coater.

Effects of the Invention As described above, according to the present invention, the defrosting cycle is started when the cooler actually frosts, instead of integrating the operating time of the compressor and automatically entering the defrosting cycle at regular intervals. Since it is a so-called demand defrost, it is efficient, and it has excellent effects such as saving power because it does not perform unnecessary defrosting, and being more economical than using a separate frost sensor.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a conventional defrosting device, FIG. 2 is a sectional view of a refrigerator equipped with a defrosting device according to an embodiment of the present invention, and FIG. 3 is a block diagram of the same defrosting device. 12...Cooler, 13...Blower, 1
6...Interior temperature detector, 17...Control circuit, 18...Compressor drive device, 19.
... Defrost heater drive device, 20 ... Blower drive device, 21 ... Current detector, 22 ...
...Judgment circuit.

Claims (2)

[Claims] (1) An internal temperature detector that detects the temperature of air that is circulated in the refrigerator by a blower and cooled by a cooler, a compressor drive device, a defrosting heater drive device, a blower, and a blower that drives the blower. a drive device, a current detector that detects the current of the blower, and a determination circuit that determines the amount of current detected by the current detector and issues a signal for a certain period of time;
A defrosting device equipped with a control circuit that controls the compressor drive device, the defrost heater drive device, and the blower drive device, respectively, based on a signal from the internal temperature detector and a signal from the determination circuit. (2) The blower uses a DC motor.
Defrosting equipment as described in section.