JPH11248331A - Refrigerator - Google Patents

Abstract

(57) [Summary] [Problem] To perform a defrosting operation at an appropriate time. A temperature detected by a temperature sensor for a cooler is read (step P1), and it is determined whether or not the detected temperature is equal to or lower than a predetermined temperature “−35 ° C.” (step P2). If it is not lower than "-35 ° C", the program returns to the main program without defrosting. If it is equal to or lower than "-35 ° C", the compressor, the cooler fan and the compressor fan are turned off and the defrost heater is turned on (step P
3). This heats the cooler, causing the frost to melt. Then, the temperature detected by the temperature sensor for the cooler becomes “+”.
13 ° C. ”or more (“ YES ”in step P5)
The defrost heater is turned off (Step P6), and the control pattern of the compressor, the cooler fan, and the compressor fan is returned to the normal cooling operation control pattern (Step P7).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a refrigerator having improved defrost control for a cooler.

[0002]

Conventionally, in a refrigerator, the operation time of a compressor is integrated, and when the integrated operation time reaches a set time (for example, 10 hours), a defrosting operation is performed each time. I have. This defrosting operation
This is performed by heating the cooler by the heater to melt the frost, and the water generated by the defrost is discharged to the evaporating dish in the machine room. The water stored in the evaporating dish is evaporated by heat of a compressor and a condenser in the machine room.

[0003] The amount of frost formed by the cooler is correlated to some extent with the cumulative time of the compressor. However, the amount of frost formed by the cooler depends on various factors such as the outside air temperature, the amount of stored food, and the frequency of opening and closing the door. The degree of idea of the vessel also varies. Therefore, when the accumulated time of the compressor reaches the set time, the amount of idea of the cooler is actually small or large. If the defrosting operation is performed while the amount of frost is small, the defrosting operation will be wasted while the cooling capacity is still sufficient, and conversely, the defrosting operation will be performed after the amount of frost increases considerably. In such a case, the defrosting operation is performed only after the cooling capacity is reduced, which may affect the stored food.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a refrigerator capable of performing a defrosting operation at an appropriate time.

[0005]

The present invention has been made by focusing on the following points. That is, during the cooling operation, the cooler is ventilated by the fan for the cooler, and the cool air is supplied to each room in the refrigerator. In this case, frost is generated and attached to the cooler sequentially, but as the amount of frost increases, the flow passage area in the cooler portion decreases. Along with this, the heat exchange rate between the cooler and the air in the refrigerator decreases, and the temperature of the cooler itself decreases. Therefore,
It is possible to appropriately determine whether or not it is time to defrost based on the temperature of the cooler itself.

According to a first aspect of the present invention, there is provided a cooler, a temperature sensor for detecting the temperature of the cooler, a heating means for removing frost attached to the cooler, and a temperature detected by the temperature sensor. And a defrosting operation control unit that starts the defrosting operation by controlling the heating unit when the temperature reaches a predetermined temperature.

In the above configuration, the degree of frost formation of the cooler can be properly detected based on the temperature detected by the temperature sensor. Then, since the defrosting operation control means starts the defrosting operation by controlling the heating means when the temperature detected by the temperature sensor reaches a predetermined temperature, the frost amount of the cooler is not too small and too large. The defrosting operation can be executed when it is not enough. As a result, the defrosting operation is not wastefully performed, and the cooling capacity does not decrease.

According to a second aspect of the present invention, there is provided a cooler, a fan for the cooler which supplies cool air to the refrigerator by ventilating the cooler, a temperature sensor for detecting a temperature of the cooler, and a fan attached to the cooler. Heating means for defrosting the frost, accumulating means for accumulating the operating time of the compressor, and any one of the fact that the temperature detected by the temperature sensor has reached a predetermined temperature or that the accumulating means has reached a predetermined time. The defrosting operation control means for controlling the heating means to start the defrosting operation under the above conditions is provided.

In this configuration, the defrosting operation is performed either when the temperature detected by the temperature sensor reaches a predetermined temperature or when the integration time by the integration means reaches a predetermined time. Can be executed efficiently.

According to a third aspect of the present invention, there is provided a compressor fan for cooling the compressor, wherein the defrosting operation control means comprises:
When the defrosting operation is started on the condition that the temperature detected by the temperature sensor has reached a predetermined temperature, the rotation speed of the compressor fan is reduced or the compressor fan is stopped after the defrosting operation is completed. It has a characteristic where it is.

In this configuration, the defrosting water evaporating action after the defrosting operation is completed is also excellent. That is, the fact that the temperature detected by the temperature sensor has reached the predetermined temperature that is the temperature for determining the start of defrosting operation means that the amount of frost formed on the cooler is always large, and therefore, when the defrosting operation is performed. ,
The amount of defrost water also increases. This defrost water is usually evaporated using the heat of the compressor. However, when the compressor fan is driven as usual, the heat radiation of the compressor is large, the heat generation temperature is low, and the defrost water evaporates. And it takes time to evaporate.

However, in the above configuration, when the defrosting operation control means starts the defrosting operation on condition that the temperature detected by the temperature sensor has reached a predetermined temperature, the rotation speed of the compressor fan is reduced after the end of the operation. To make
Alternatively, since the compressor fan is stopped, the heat generation temperature of the compressor is increased, which greatly contributes to the evaporation of the defrost water, and the evaporation time can be reduced.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS. 2 and 3 showing the entire configuration of the refrigerator, the refrigerator main body 1 accommodates a plastic inner box 3 in an iron plate outer box 2,
The space between the outer box 2 and the inner box 3 is filled with a foamable heat insulating material 4. The refrigerator body 1 includes a refrigerator room 5 and an ice making room 6 arranged side by side in order from the top as a storage room.
Further, a specification switching room 7, a freezing room 8, and a vegetable room 9 are provided, and each of the rooms 5 to 9 is opened and closed by doors 10 to 14.

Among these storage rooms, the specification switching room 7 can switch its cooling temperature in a wide range, and by switching, can be selected from a freezing room, a partial freezing room, a chilled room, a refrigerator room and a vegetable room. You can use it. The doors 11 to 14 of the storage rooms 6 to 9 other than the refrigeration room 5 are of a drawer type, and containers 6 a to 9 a for storing food (the containers of the specification switching room 7 are not shown) are doors 11 to 11. 14 and can be pulled out.

The ice making compartment 6 and the freezing compartment 8 which are present in the upper and lower two stages have the same temperature zone and are in communication with each other.
It is only divided up and down by a front horizontal frame 15 provided between 1 and 12 and the door 13 of the freezer compartment 8.

A cooler room 16 is formed at the rear of the ice making room 6 and the freezing room 8.
A cooler 17 is provided therein. The cooler room 16 is formed by disposing a partition member 18 at the rear of the ice making room 6 and the freezing room 8 so as to cover the front side of the cooler 17. The partition member 18 is configured by connecting a front partition plate 19 and a rear partition plate 20.
The rear partition plate 20 is provided with a cooler fan 21. The cooler fan 21 includes a fan motor 21a and a blower blade 21b.

A cold air supply passage 22 is formed between the front and rear partition plates 19 and 20, and the rear partition plate 19 of the two partition plates 19 and 20 is provided in the ice making chamber 6 and the freezing chamber 8. Opening outlets 23 are formed in a plurality of upper and lower stages. Although not shown, the rear partition plate 20 is provided with a cool air outlet communicating with the refrigerator compartment 5 and the specification switching chamber 7 via a damper device (neither is shown).

When the cooler fan 21 is driven, the cool air in the cooler chamber 16 is sucked by the blower blades 21b and sent out to the cool air supply passage 22, and the cool air sent into the cool air supply passage 22 is removed. From the outlet 23 to the ice making room 6
The remaining cool air is blown out into the freezer compartment 8 and the remaining cool air is sent from the cool air outlet into the refrigerating room 5 and the specification switching room 7 via the damper device.

The cool air supplied to the ice making room 6, the freezing room 8, and the specification switching room 7 is supplied to the cooler room through a reflux passage 25 provided on the heat insulating partition wall 24 between the freezing room 8 and the vegetable room 9. 16
Will be returned within. The cool air supplied to the refrigerator compartment 5 is supplied to the vegetable compartment 9 through a duct (not shown), and thereafter,
The heat is returned to the cooler room 16 through another return path 26 provided in the heat insulating partition wall 24.

As described above, since the moisture contained in the air adheres to the cooler 17 for cooling the air circulating in the refrigerator as frost, it serves as a heating means for forcibly melting the frost. A defrost heater 27 is provided below the cooler 17. And the water generated by this defrost is
The water is received by the gutter 16a at the bottom of the cooler room 16 and is discharged to the outside through a drain pipe 28 as a drain passage.

On the other hand, a machine room 29 is provided on the outside of the bottom of the refrigerator body 1 at the rear side of the vegetable room 9. In the machine room 29, a compressor fan 31 for cooling the compressor 30 is provided. The compressor fan 31 includes a fan motor 31a and a blower blade 31b. The compressor fan 31 is also used for cooling a condenser and the like.

An evaporating dish 30a is provided above the compressor 30, and the drain pipe 28 faces the evaporating dish 30a. Therefore, the water generated by the defrost is finally stored in the evaporating dish 30a, and is evaporated by the heat of the compressor 30 and the condenser.

Here, the structure of the cooler 17 will be briefly described with reference to FIG. 4. The cooler 17 is a meandering pipe (heat exchange pipe) 17 connected to a refrigeration cycle.
a, a large number of fins 17c are attached to the end plates 17b, 17b.
The heat is well exchanged by passing through the space 7c. Further, a temperature sensor 36 for a cooler, which will be described later, which is a temperature sensor, is attached to one end plate 17b via an attachment 36a.

FIG. 5 shows a control structure mainly for the defrosting of the refrigerator. In the figure, a control device 32 as a defrosting operation control means is mainly composed of a microcomputer.
Temperature sensor 33 for the freezer compartment for detecting the temperature inside the refrigerator compartment 5
A temperature sensor 34 for the refrigerator compartment for detecting the temperature in the inside, a temperature sensor 35 for the specification switching room for detecting the temperature in the specification switching chamber 7,
An output signal of a cooler temperature sensor 36 for detecting the temperature of the cooler 17 is provided. The control device 32 controls the drive of the cooler fan 21, the defrost heater 27, the compressor 30, and the compressor motor 31. In particular, the control device 32 controls the number of revolutions of the compressor fan 31. It is configured.

When the freezing room temperature sensor 33 detects the ON temperature or higher during the normal cooling operation, the control device 32 controls the compressor 30 and the cooling fan 21.
When the operation of the compressor fan 31 is started and the temperature of the compressor fan 31 is detected to be equal to or lower than the OFF temperature, the operation of the compressor 30, the cooler fan 21, and the compressor fan 31 is stopped. Further, the control device 32 controls the opening and closing of the damper devices of the refrigerator compartment 5 (vegetable compartment 9) and the specification switching room 8 in accordance with the temperatures detected by the temperature sensor 34 for the refrigerator compartment and the temperature sensor 35 for the specification switching room. The supply of cold air to the chambers 5 and 8 is controlled. Here, during the normal cooling operation, as described above, the cooling fan 21 is also turned on and off with the turning on and off of the compressor 30. When the fan 21 is turned on, the air in the refrigerator is cooled through the cooler 17 and supplied to each room, but the humidity of the air in the refrigerator gradually forms frost on the cooler 17. . In this case, as the frost accumulates, the space between the fins 17c in the cooler 17 or the space between the cooler 17 and the cooler chamber 16 becomes clogged, and the flow path area becomes smaller. In this case, the heat exchange rate between the cooler 17 and the internal air decreases, and the temperature of the cooler 17 itself decreases.

The inventor of the present invention has thus found that a large amount of frost is correlated with a decrease in the temperature of the cooler 17, and focusing on this finding, in the present embodiment, "-35 ° C
Is used as a guide to detect the amount of frost to be defrosted. During a normal cooling operation (an operation state in which each room is maintained at the set temperature), the temperature of the cooler 17 is set to “−3”.
It was found that the temperature did not fall below “5 ° C.”, and when the temperature fell below “−35 ° C.”, the temperature of each room could not be controlled to the set temperature.

Now, the control device 32 operates as shown in FIG.
The following control is executed. This defrost control program is periodically executed in a main program for performing overall control of the refrigerator. First, in step P1, the output signal of the cooler temperature sensor 36, that is, the detected temperature is read, and in step P2, the detected temperature is a predetermined temperature “−35”.
° C ”or less. If it is not equal to or lower than "-35 ° C"("NO" in step P2), the process returns to the main program without defrosting. If it is “−35 ° C.” or less, the process proceeds to Step P3, in which the compressor 30, the cooler fan 21, and the compressor fan 31 are turned off.
Further, the defrost heater 27 is turned on. With this, the cooler 17
Is heated and the frost melts.

In the next steps P4 and P5, the temperature detected by the cooler temperature sensor 36 is read, and it is determined whether or not the detected temperature is equal to or higher than "+ 13 ° C." which is the defrost end detection temperature. ° C ”or more (“ YES ”in step P5), the process proceeds to step P6, where the defrost heater 27 is turned off, and then proceeds to step P7.
The compressor 30, the cooler fan 21, and the compressor fan 31 are returned to the normal cooling operation control pattern.

As described above, according to the present embodiment, the degree of frost formation of the cooler 17 is detected by judging whether or not the temperature detected by the cooler temperature sensor 36 has reached a predetermined temperature. Frost formation degree can be detected properly. Then, when the temperature detected by the cooler temperature sensor 36 reaches a predetermined temperature, the defrosting operation (defrost heater 27 is turned on) is started, so that the amount of frost on the cooler 17 is not too small and not too large. When it becomes, the defrosting operation can be executed. As a result, the defrosting operation is not wastefully performed, and the cooling capacity does not decrease.

FIG. 6 shows a second embodiment of the present invention. In this embodiment, the control device 32 has a function as an integrating means for integrating the operation time of the compressor 30, and the function as a defrosting operation control means is slightly different from the first embodiment. Further, the predetermined temperature for detecting the start of defrosting is “−35 ° C.” slightly higher than “−35 ° C.” in the first embodiment.
3 ° C. ”.

In FIG. 6, if the temperature detected by the cooler temperature sensor 36 is not "-33.degree. C." or less ("NO" in step Q2), the process proceeds to step Q3, where the integration time is equal to the predetermined time. It is determined whether or not a certain time, for example, “10 hours” has been reached. If the time has not been reached, the process returns to the main program without performing the defrosting operation. Then, the above step Q
In step Q4, it is determined whether the detected temperature is equal to or lower than “−33 ° C.” or in step Q3 that the accumulated time has reached “10 hours”.
The process proceeds to Step Q6 to execute the defrosting operation. When the completion of the defrosting is detected, the process proceeds to step Q7 to turn off the defrost heater 27, and then proceeds to step Q8, where the compressor 30 and the cooler fan 21 (referred to as "E fan" in the flowchart of FIG. 6). Is returned to the normal cooling operation control pattern. Then, the process proceeds to step Q9, in which the compressor fan 31 is turned on.

According to the second embodiment, the defrosting operation is performed regardless of whether the temperature detected by the cooler temperature sensor 36 has reached the predetermined temperature or the accumulated time of the compressor 30 has reached the predetermined time. When the amount of frost increases unexpectedly due to frequent opening and closing of the door, etc., defrosting can be performed based on the temperature sensor for the cooler 36, and when the amount of frost increases gradually, the accumulated time And the defrosting operation can be efficiently executed.

Further, according to this embodiment, when the defrosting operation is started on condition that the temperature detected by the cooler temperature sensor 36 has reached a predetermined temperature, the rotation speed of the compressor fan 31 is reduced after the end of the defrosting operation. Therefore, the defrosting water evaporating action after the defrosting operation is completed is also excellent. That is, the fact that the temperature detected by the cooler temperature sensor 36 has reached the predetermined temperature which is the temperature for judging the start of the defrosting operation means that the frost amount of the cooler 17 is always large (the frost amount detection is Since it is accurate, the amount of frost is rather large at the time of detection), and therefore, when the defrosting operation is performed, the amount of defrost water is also large. This defrost water is usually evaporated by utilizing the heat of the compressor 30. However, when the compressor fan 31 is driven as usual, a large amount of heat is released from the compressor 30 and contributes to the evaporation of the defrost water. And it takes time to evaporate.

However, in this embodiment, when the defrosting operation is started on condition that the temperature detected by the cooler temperature sensor 36 has reached a predetermined temperature, the rotation speed of the compressor fan 31 is reduced after the defrosting operation is completed. The temperature of the heat generated by the compressor 30 increases, which greatly contributes to the evaporation of the defrost water, and the evaporation time can be reduced.

In this case, the temperature sensor 36 for the cooler is used.
When the defrosting operation is started on condition that the temperature detected by the compressor becomes a predetermined temperature, the rotation speed of the compressor fan 31 is not reduced after the completion thereof,
7, the compressor fan 31 may be stopped for a certain period of time (step R9 corresponds to this control). In such an embodiment, the same effect as in the second embodiment can be obtained.

[0036]

As apparent from the above description, the present invention has the following effects. According to the first aspect of the invention, it is possible to appropriately detect the degree of frost formation of the cooler based on the temperature detected by the temperature sensor. Moreover, since the defrosting operation is started by controlling the heating means when the temperature detected by the temperature sensor reaches a predetermined temperature, when the amount of frost formed on the cooler is not too small and not too large, The defrosting operation can be performed, so that the defrosting operation is not wastefully performed and the cooling capacity does not decrease.

According to the second aspect of the present invention, the defrosting operation is executed regardless of whether the temperature detected by the temperature sensor has reached the predetermined temperature or the integration time of the integrating means has reached the predetermined time. In addition, the defrosting operation can be performed efficiently. According to the third aspect of the present invention, when the defrosting operation is started on condition that the temperature detected by the temperature sensor has reached a predetermined temperature, the rotation speed of the compressor fan is reduced after the defrosting operation is completed, or the compressor fan Is stopped, which can greatly contribute to the evaporation of the defrost water due to the heat generated by the compressor, thereby shortening the evaporation time.

[Brief description of the drawings]

FIG. 1 is a flowchart of defrosting control according to a first embodiment of the present invention.

FIG. 2 is a longitudinal sectional side view of a refrigerator.

FIG. 3 is a front view of the refrigerator.

FIG. 4 is a perspective view of a cooler.

FIG. 5 is a block diagram of an electrical configuration.

FIG. 6 is a view corresponding to FIG. 1, showing a second embodiment of the present invention;

FIG. 7 is a view corresponding to FIG. 1, showing a third embodiment of the present invention;

[Explanation of symbols]

16 is a cooler room, 17 is a cooler, 21 is a cooler fan, 27 is a defrost heater (heating means), 31 is a compressor fan, 32 is a control device (defrost operation control means, integrating means), 36 is 3 shows a temperature sensor (temperature sensor) for a cooler.

Claims (3)

[Claims] 1. A cooler, a fan for a cooler that ventilates through the cooler and supplies cool air into a refrigerator, a temperature sensor that detects a temperature of the cooler, and defrosts frost adhering to the cooler. And a defrosting operation control means for controlling the heating means to start a defrosting operation when the temperature detected by the temperature sensor reaches a predetermined temperature. 2. A cooler, a fan for a cooler that supplies cool air to the inside of the refrigerator by ventilating the cooler, a temperature sensor for detecting a temperature of the cooler, and defrosting frost adhering to the cooler. Heating means for performing the operation, the integrating means for integrating the operating time of the compressor, on the condition that either the temperature detected by the temperature sensor has reached a predetermined temperature, or that the integrating means has reached a predetermined time, A refrigerator comprising: a defrosting operation control unit that starts the defrosting operation by controlling the heating unit. 3. A compressor fan for cooling the compressor, wherein the defrosting operation control means starts the defrosting operation on condition that a temperature detected by a temperature sensor has reached a predetermined temperature, and after the completion of the defrosting operation, 3. The washing machine according to claim 2, wherein the number of revolutions of the fan is reduced or the fan for the compressor is stopped.