JPH06249566A - Defrosting control device for refrigerator - Google Patents

Abstract

PURPOSE:To provide a defrosting control device for refrigerator in which some disadvantages of starting a defrosting operation under a condition of abnormally short defrosting period and scarcely having a frosted state within a cooler are eliminated and a defrosting starting time is determined in such a manner that the defrosting can be started instantly even under an abnormal frosting state. CONSTITUTION:A control device 45 including an operation accumulation counter 54 for accumulating an operating time of a compressor, a converting means 55 for converting the times of opening or closing of a door into a time and a door closing counter 57 for measuring a time in which the door is kept closed and for controlling an electrical energization for a defrosting heater 36 determines a defrosting starting time of a cooler in reference to an operating time of a compressor 31 accumulated by the operation accumulation counter and a time converted by the converting means. When the time measured by the door closing counter elapses more than a predetermined time, the defrosting heater is electrically energized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a defrost control device for a refrigerator.

[0002]

2. Description of the Related Art Generally, the amount of frost formed on a cooler changes depending on the amount of food and the frequency of food intake and removal (≈number of times the door is opened and closed). When the frost grows to cover the surface of the cooler, the heat exchange capacity of the cooler and the amount of cold air circulated to the inside of the refrigerator decrease, and the cooling capacity decreases. The method of defrosting is taken by stopping the operation of the machine and energizing the defrosting heater.

As a method for determining the defrosting start time, for example, as shown in Japanese Patent Laid-Open No. 4-121569, a time obtained by adding a time obtained by converting the number of times of opening and closing of a door to the time is added to the operation cumulative time of the compressor. The defrosting start time is set when a certain period of time or more is set, and the opening and closing of the door is reduced in the winter when the operation rate is low, and when the frost does not frost on the cooler, the defrosting start time is delayed to waste. There is a method to avoid such defrosting. Further, in Japanese Patent Publication No. 59-38506, the number of times the door is opened and closed is integrated, and defrosting is started when the integrated value reaches the defrosting start value, and the next time from the time required for defrosting and the previous integrated value, There is disclosed a defrosting control device that determines a defrosting start value.

[0004]

When the defrosting start time is determined only by the cumulative operating time of the compressor, defrosting may start while the door is open, and the user may be distrusted. Not only does it give a feeling, but the cold air inside the refrigerator escapes by opening the door, and the outside air enters the refrigerator.In addition, the cooling operation is stopped, causing the temperature inside the refrigerator to rise abnormally. The food in the refrigerator may be adversely affected.

Further, according to the defrosting timing determining method and the defrosting device disclosed in both of the above publications, when the number of times of opening and closing of the door is abnormally large, the defrosting is performed even when the compressor is hardly operated. May start. In addition, only the number of times the door is opened and closed is the main factor in determining the defrosting start time.For example, when the humidity of the outside air is abnormally high, when the door is open for an abnormally long time compared to the operation of taking food in and out (i.e., the door is open). (When forgetting to close), or when a so-called abnormal situation occurs when a large amount of uncooled food is put in the refrigerator, the defrosting start time is significantly delayed from the appropriate time and the food in the refrigerator is ruined. There is.

Therefore, the present invention eliminates the problem that defrosting is started even when the defrosting start timing, which is the above-mentioned conventional problem, is abnormally short and there is almost no frost on the cooler.
Another object of the present invention is to provide a defrosting control device for a refrigerator that determines the defrosting start time so that defrosting can be started immediately even when an abnormal situation occurs.

[0007]

The present invention has a counter for integrating the operating time of a refrigerant compressor, and a conversion means for converting the number of times of opening and closing of a door into time, and controls energization of a defrost heater. The control device determines the defrosting start time of the cooler by the operating time of the refrigerant compressor accumulated by the counter and the opening / closing time of the door converted by the conversion means, and the operating time of the refrigerant compressor is predetermined. The defrosting heater is energized when a predetermined time or more has elapsed.

Further, the present invention has an operation integration counter for integrating the operation time of the refrigerant compressor, a conversion means for converting the number of times of opening and closing of the door into time, and a door closing counter for measuring the time when the door is in the closed state. However, the control device for controlling the power supply to the defrost heater, the defrost start time of the cooler by the operating time of the refrigerant compressor accumulated by the operation integrating counter and the door opening and closing time converted by the conversion means. Is determined, and when the time measured by the door opening / closing counter has exceeded a predetermined time, the defrost heater is energized.

Further, according to the present invention, the refrigerant compressor is turned on and off based on a signal from a temperature sensing element which is installed in the freezing chamber and detects the temperature of the freezing chamber, and is mounted on the cooler to detect the temperature of the cooler. The controller for ending the defrosting of the cooler based on the signal from the temperature element, the defroster of the refrigerator adapted to energize the defrosting heater when the difference between the temperatures detected by the temperature sensing elements is larger than a predetermined value. A frost control device is provided.

Further, according to the present invention, the refrigerant compressor is turned on and off based on a signal from a temperature sensing element which is installed in the freezer compartment and detects the temperature of the freezer compartment, and is attached to the cooler to detect the temperature of the cooler. The control device that ends the defrosting of the cooler based on the signal from the temperature element includes a counter that measures the continuous operation time of the refrigerant compressor, and the time measured by this counter has exceeded a predetermined time or more. At this time, and when the difference between the temperatures detected by the temperature sensitive elements is larger than a predetermined value, the defrost heater is energized.

Further, according to the present invention, the refrigerant compressor is turned on and off based on a signal from a temperature sensing element which is installed in the freezing chamber and detects the temperature of the freezing chamber, and is installed in the cooler to detect the temperature of the cooler. The control device that terminates the defrosting of the cooler based on the signal from the temperature element includes a continuous operation counter that measures the continuous operation time of the refrigerant compressor, and a door closing counter that measures the time of the door closed state, The time measured by the continuous operation counter has passed a predetermined time or more, and the time measured by the door closing counter has passed a predetermined time or more, and the temperature difference between the two temperature sensing elements is predetermined. When the value is larger than the value, the defrost heater is energized.

In other words, one that integrates the operating time of the compressor, one that converts the number of times of opening and closing the door into time, one that integrates the continuous operating time of the compressor, one that integrates the time of the door closed state, and an emergency exclusion Counters are provided to integrate the time after the frost start temperature is detected, and are divided by signals from the counters, signals from the temperature sensors inside the refrigerator and the cooler, and signals from the switch that detects the opening and closing of the door. The frost start time is decided.

[0013]

According to the first aspect of the present invention, the defrosting start timing of the cooler is determined by a predetermined method according to the cumulative operating time of the compressor and the number of times the door is opened and closed. The operating time of the compressor is a predetermined time. If the above conditions are not satisfied, defrosting will not be started, and thus defrosting start can be avoided when the operating rate of the compressor is low only by abnormally opening and closing the door.

According to the second aspect of the present invention, the defrosting start timing of the cooler is determined by a predetermined method according to the cumulative operation time of the compressor and the number of times the door is opened and closed. The door is opened at the determined defrosting start timing. Even if the door is closed, the defrosting is not started unless a predetermined time or more has passed since the door was closed, so that the defrosting is not started when the door is opened as in the conventional case.

According to the third aspect of the present invention, it is determined that the frost blockage of the cooler occurs when the temperature difference between the temperature of the freezer compartment and the temperature of the cooler is larger than a predetermined value. The frost can be started and the deterioration of the cooling capacity can be canceled early.

According to the fourth aspect of the present invention, it is determined that the frost blockage of the cooler is obtained by taking into account the temperature difference between the freezer compartment and the cooler and the case where the continuous operation time of the compressor has exceeded a predetermined time. By preventing misjudgment due to temporary temperature rise in the freezer when power is turned on or when defrosting is completed, the accuracy of frost blockage determination is further improved, and abnormalities can be detected more reliably and defrosting is started urgently. The decrease in cooling capacity can be canceled early.

According to the fifth aspect, in addition to the temperature difference between the freezer compartment and the cooler and the continuous operation time of the compressor, the frost on the cooler is taken into consideration when the state in which the door is closed has exceeded a predetermined time. It is determined that the frost is closed and the accuracy of the frost blockage is further improved by preventing misjudgment due to the temperature rise in the freezer room that occurs temporarily when opening and closing the door and putting food that is not cold. In addition, it is possible to detect the occurrence of an abnormality more reliably, to start defrosting urgently, and to cancel the decrease in cooling capacity as soon as possible. Defrosting will no longer start when the door is opened as in the past.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIGS. 1 is a vertical side view of a refrigerator, FIG. 2 is a schematic block circuit diagram of a defrost control device of the present invention, and FIG.
FIG. 4 and FIG. 4 are flowcharts illustrating an operation flow for determining the defrosting start time of the control device.

In FIG. 1, reference numeral 1 is a household refrigerator, and this refrigerator has a heat-insulating box body 2 having a front opening which constitutes the main body thereof.
And doors 3, 4, and 5 that close the opening of this box. The door 3 is a pivotable door corresponding to a refrigerating compartment 13 described later, the doors 4 and 5 are drawer type doors, the door 4 corresponds to the freezing compartment 14, the door 5 corresponds to the vegetable compartment 15. ing.

Reference numerals 11 and 12 denote horizontal partition walls for partitioning the inside of the heat insulating box 2 into upper, middle and lower three steps. In this embodiment, the partition wall 11 is used.
Above, the refrigerating chamber 13 that is cooled to a temperature at which food does not freeze (eg, about 3 ° C.), the freezing chamber 14 above the partition wall 12 to a freezing temperature (eg, about −20 ° C.), and the lower part is refrigerated. The vegetable compartment 15 is cooled to a temperature (for example, about 7 ° C.) which is slightly higher than the temperature of the compartment and is suitable for storing vegetables. Further, a container 16 for storing frozen food is provided on the door 4,
A container 17 for storing vegetables is attached to each door 5.

A partition plate 18 is arranged at the back of the freezing compartment 14, and a plate fin type evaporator 19 as a cooler and a blower 20 such as a propeller fan are arranged behind the partition plate 18.
Is formed in the cooler chamber 21.

Reference numeral 22 is a refrigerating cold air duct for supplying the cool air cooled by the evaporator 19 to the freezing chamber 14 from the outlet 22A, and 23 is cold air passing through the horizontal partition wall 11 and cooled by the evaporator 19. Is a cold air duct for refrigeration for supplying the cold air to the refrigerating compartment 13, and 24 is a cold air duct for distribution which communicates with the cold air duct 23 for refrigerating and supplies cold air by distributing the cold air from the outlets 24A and 24B. Reference numeral 25 denotes a damper device, which is a so-called shape memory damper, which is arranged at a connection portion between the cold air duct 23 for refrigeration and the cold air duct 24 for distribution.

A machine room 33, in which the compressor 31 and the evaporation tray 32 are arranged, is formed in the lower part and the rear part of the heat insulating box 2. Reference numeral 35 denotes a dew pan disposed below the evaporator 19, and 36 denotes a defrosting heater such as a quartz glass tube heater or a Vycor tube heater arranged between the dew pan 35 and the evaporator 19. The platinum-based ceramic deodorizing catalyst is laminated on the surface of the glass tube of the defrosting heater 36 and baked. With this defrosting heater 36, the compressor 3
During operation 1 (that is, during cooling operation), the odorous component of cold air including the odorous component returning to the lower side of the evaporator 19 is adsorbed,
It can be exchanged with the evaporator as clean cool air, and during operation of the defrost heater (that is, during defrost operation), the adsorbed odorous components are oxidatively decomposed by the platinum-based catalyst and Activated and clean air can be produced.

The horizontal partition wall 12 extends from a cold air suction port 37A formed in the front portion of the lower surface of the horizontal partition wall 12 to a return port 37B formed in the rear portion of the partition wall 12 and below the evaporator. It is a cold air return passage that extends in the front-rear direction inside. Reference numeral 38 is a water pipe for guiding defrost water from the dew tray 35 to the evaporation tray 32.

In FIG. 2, reference numeral 41 is an F-door open / close detection means such as a mechanical switch which outputs a signal by detecting a change of the freezer compartment door 4 from open to closed and a change from closed to open. R door open / close detection means such as a mechanical switch that detects a change from opening to closing and a change from closing to opening of the chamber door 3 and outputs a signal, and 43 is arranged near the cold air outlet 22A of the freezing chamber 14 F as a temperature sensitive element for detecting the temperature of the freezer
A sensor (hereinafter referred to as an F sensor) 44 is a DEF sensor (hereinafter referred to as a DEF sensor) as a temperature-sensitive element which is arranged above the cooler 19 and detects the temperature of the cooler, and 46 is an F door opening / closing detection means 41, R door open / close detection means 42,
It is a microcomputer (hereinafter referred to as a microcomputer) as a control means for inputting data from the F sensor 43 and the R sensor 44 via the interface 45. The microcomputer 46 A / D-converts the input data by the A / D converter 50, performs a predetermined arithmetic processing, and then outputs a signal (data) for driving the compressor to the drive circuit 47 to operate the compressor 31. To control.

A random write / read memory (hereinafter referred to as RAM) 52 of the microcomputer 46 includes an operation time integration counter 54 for integrating the operation time of the compressor, and the operation time of the compressor for converting the number of times of opening and closing the door into time. Defrosting time correction counter 55 configured to perform addition, a continuous operation counter 56 that measures the continuous operation time of the compressor, a door close counter 57 that measures the time of the closed state of the door, and an F sensor 43. An emergency defrosting temperature counter 58 that measures the time when the frosting abnormality is determined by the temperature difference between the temperatures detected by the DEF sensor 44 is set, and the timer mounted on the microcomputer 46 passes one minute. Each time, the counter is configured to count up. Each counter 54-
When 58 is equal to or more than a predetermined value, it is considered that the time is up.

The microcomputer 46 determines the defrosting start time based on the above data and controls the energization of the defrosting heater 36.

FIG. 3 is a flow chart showing an operation flow for determining the defrosting start timing in the defrosting control apparatus S of the present invention, and the details will be described below. The control for determining the defrosting start time is performed from the state where all the counters are cleared by turning on the power or ending the defrosting.

First, if it is confirmed in step S1 that one minute has elapsed, it is confirmed in step S2 whether the compressor is on or off. If the compressor is off, in step S3 the continuous operation counter 5
6 is cleared, the continuous operation flag is reset, and the process proceeds to step S7. If the compressor is on, step S4
The count value of the operation integration counter 54 is increased by 8 and the time is increased in 8 hours to set the DEF limit flag.

Next, in step S5, the defrosting time correction counter 55 is incremented, and the time is decremented in 30 hours.
Set the correction flag. Next, in step S6, the continuous operation counter 56 is incremented, the time is incremented in 55 minutes, and the continuous operation flag is set. Next, in step S7, the state of the door is confirmed regardless of whether the compressor is on or off. If all the doors (both the F door and the R door here) are not closed, the door close counter 57 is cleared in step S8, the door close flag is reset, and the process proceeds to step S10. If all the doors (both the F door and the R door in this case) are in the closed state, the door close counter 57 is incremented in step S9 to increase the time in 5 minutes, and the door closed flag is set.

Next, in step S10, it is confirmed whether or not the F door is changed from the closed state to the open state. Only when the F door is changed from the closed state to the open state, the defrosting time correction counter 55 is set to F in the step S11.
The door correction time (for example, 27 minutes) is added, and if the counter is 30 hours or more, the time is increased and the DEF correction flag is set.

Next, in step S12, it is confirmed whether or not the R door is changed from closed to open. Only when the R door is changed from closed to open, the defrosting time correction counter 55 is set to R in step S13.
The door correction time (for example, 21 minutes) is added, and if the counter is 30 hours or more, the time is increased and the DEF correction flag is set.

The microcomputer 46 determines the defrosting start time by the above various control flags, and the control method (determination method) will be described below with reference to FIG.

First, in step S14, the presence or absence of the continuous operation flag is confirmed. If the flag is set, the presence or absence of the door closing flag is confirmed in step S15. If the flag is set, it is checked in step S16 whether the temperature difference between the temperatures detected by the F sensor 43 and the DEF sensor 44 is equal to or higher than the preset emergency defrosting temperature (for example, 12 ° C.). If the temperature is 12 ° C. or higher, the emergency defrosting temperature counter 58 is increased in step S17, and the emergency defrosting start determination time (for example, 5 minutes) is timed up to output a defrosting start signal (data) from the microcomputer 46. Compressor 3
1 is stopped (turned off) and the defrost heater 36 is energized to start defrosting.

In this way, if it is determined in step S17 that an abnormal situation has occurred in the refrigerator, the emergency defrosting is started, so that the defrosting start time is greatly delayed in the event of an abnormality such as forgetting to close the door. Disappears.

It should be noted that either the continuous operation flag or the door closing flag is reset, or the F sensor 43
If the temperature difference between the temperatures detected by the DEF sensor 44 and the DEF sensor 44 is less than the emergency defrosting temperature, the emergency defrosting temperature counter 58 is cleared in step S18, and the process proceeds to step S19.

Next, in step S19, it is confirmed whether or not the DEF limit flag is present. If the flag is set, the presence or absence of the DEF correction flag is checked in step S20.
If the flag is set, the presence or absence of the door closing flag is confirmed in step S21. If the door closing flag is set, the defrosting start signal (data) is output from the microcomputer 46 in step S22 to stop (turn off) the compressor 31, and the defrosting heater 36 is energized to start defrosting.

According to the above construction, when the power is turned on or the defrosting is completed, the compressor and the blower are operated, the operating time integration counter 54 of the compressor starts operating, and the fact that the door is opened at this time is a mechanical switch. Door opening / closing detection means 41, 42, etc.
If it is confirmed by, the value obtained by converting the number of times of opening and closing of the door (in this case, 1 time) into the time accumulated by the counter 54 and adding it (for example, F door: 27 minutes, R door: 21 minutes) is excluded. Set as frost start correction time. The defrosting start correction time exceeds a predetermined time (for example, 30 hours), and the time after the doors (in this embodiment, both the freezing compartment door and the refrigerating compartment door) are closed is integrated. When the time accumulated by the door closing time accumulating counter 57 has passed a predetermined time (for example, 5 minutes) or more, and the operation cumulative time exceeds the predetermined time (for example, 8 hours), Start the frost.

Further, the compressor is continuously operated for a predetermined time (for example, 55 minutes) or more, and the temperature of the freezer compartment detected by the temperature sensing element 43 installed in the freezer compartment is the cooler 19.
When it is confirmed that the state in which the temperature is higher than the temperature of the cooler detected by the temperature sensing element 44 attached to the predetermined temperature (for example, 12 ° C.) or more has passed the predetermined time (for example, 5 minutes) or more Can determine that the cooling capacity has deteriorated due to a large amount of frost adhering to the cooler and start defrosting.

In the above embodiment, the cumulative operation time (8 hours)
Converted time per opening / closing of F door and R door (27 minutes, 21
Although the addition method of adding the minute) and the elapsed time has been described, a subtraction method of subtracting the conversion time and the elapsed time per opening / closing of the F door and the R door from the defrosting start correction time (30 hours) may be used.

As described above, when the defrosting start time is changed according to not only the number of times of opening and closing the door but also the time after the door is closed, it is possible to avoid starting defrosting at the same time as opening the door, Also, since the defrost start time can be delayed when the number of times of opening and closing of the door is abnormally large and the defrost start time becomes extremely short, the malfunction of starting defrost when there is almost no frost on the cooler is prevented. it can.

Also, when the humidity is abnormally high, forgetting to close the door,
When the cooling capacity decreases due to external factors such as putting food that is not cold inside the refrigerator, it is judged as abnormal frosting and immediately defrosting is started, so that the decrease in cooling capacity is released early and is good. It is possible to perform a proper cooling operation.

As described above, in the present invention, the defrost correction time obtained by adding the correction time due to the opening and closing of the door to the cumulative operation time of the compressor which starts after the start of the operation of the refrigerator / freezer or the end of defrost has been set for a preset time ( If the defrosting start time is changed when the time exceeds 30 hours) and the defrosting start time is changed, the defrosting starts when the door opening / closing frequency is low, that is, when the defrosting amount is small relative to the operating time of the compressor. It is possible to avoid unnecessary defrosting by delaying the time, and when the number of times of opening and closing of the door is large, it is judged that the defrosting amount is large relative to the operating time of the compressor, and the defrosting start time is advanced to ensure defrosting. It is possible to avoid defrosting at the same time as opening the door, by adding the condition that defrosting is performed only when the closed state of the door has elapsed for a specified time (10 minutes) or more. By that, the refrigerator It is possible to prevent giving the distrust to use person, can be prevented to adversely affect even the food in the refrigerator will stop the addition cooling to cold air escapes by opening the Matatobira.

Further, the defrosting start time that can be surely defrosted when the door is opened and closed is set to the minimum time (8 hours),
The defrosting start minimum time is provided so that defrosting does not start when the accumulated operating time has not passed this minimum time.When the compressor operating time is short, the number of times the doors are opened and closed abnormally increases. The defrosting start time is almost determined by the correction time of 1, and the defrosting start time can be prevented from becoming extremely short.

If frost is abnormally attached to the cooler in a short time due to abnormally high humidity, forgetting to close the door, or putting food that is not cold in the refrigerator, the compressor will Since the temperature difference between the F sensor and the DEF sensor becomes extremely wide during continuous operation, when all the doors are closed, the temperature difference exceeds a preset value (12 ° C) and it is judged that frosting is abnormal. Start emergency defrost. By this emergency defrosting, defrosting can be surely performed, and it is possible to prevent a decrease in cooling capacity due to clogging of frost.

[0046]

According to the first aspect of the present invention, the defrosting start timing of the cooler is determined by a predetermined method according to the cumulative operating time of the compressor and the number of times the door is opened and closed, but the operating time of the compressor is predetermined. Since the defrosting is not started unless the time is longer than the predetermined time, it is possible to avoid the defrosting start when the operating rate of the compressor is low only by abnormally opening and closing the door.

According to the second aspect of the present invention, the defrosting start timing of the cooler is determined by a predetermined method depending on the cumulative operation time of the compressor and the number of times the door is opened and closed. The door is opened at the determined defrosting start timing. Even if the door is closed, the defrosting is not started unless a predetermined time or more has passed since the door was closed, so that the defrosting is not started when the door is opened as in the conventional case.

According to the third aspect of the present invention, it is judged that the frost blockage has occurred in the cooler by catching the case where the temperature difference between the freezer compartment temperature and the cooler temperature is larger than a predetermined value. The frost can be started and the deterioration of the cooling capacity can be canceled early.

According to the fourth aspect, it is judged that the frost is closed in the cooler by catching the temperature difference between the freezer compartment and the cooler and the case where the continuous operation time of the compressor exceeds a predetermined time. By preventing misjudgment due to temporary temperature rise in the freezer when power is turned on or when defrosting is completed, the accuracy of frost blockage determination is further improved, and abnormalities can be detected more reliably and defrosting is started urgently. The decrease in cooling capacity can be canceled early.

According to the fifth aspect, in addition to the temperature difference between the freezer compartment and the cooler and the continuous operating time of the compressor, the frost on the cooler is taken into consideration when the door is closed for more than a predetermined time. It is determined that the frost is closed and the accuracy of the frost blockage is further improved by preventing misjudgment due to the temperature rise in the freezer room that occurs temporarily when opening and closing the door and putting food that is not cold. In addition, it is possible to detect the occurrence of an abnormality more reliably, to start defrosting urgently, and to cancel the decrease in cooling capacity as soon as possible. Defrosting will no longer start when the door is opened as in the past.

[Brief description of drawings]

FIG. 1 is a vertical side view of a refrigerator of the present invention.

FIG. 2 is a schematic block circuit diagram of a control device of the present invention.

FIG. 3 is a flowchart illustrating a defrosting start timing determination operation of the control device.

FIG. 4 is a flowchart illustrating a defrosting start timing determination operation of the control device.

[Explanation of symbols]

 1 Refrigerator S Defrost control device 31 Compressor 36 Defrost heater 41 F Door open / closed detection element 42 R Door open / closed detection element 43 F sensor (temperature sensitive element) 44 DEF sensor (temperature sensitive element) 45 Microcomputer input signal conversion interface 46 Control microcomputer (control means) 47 drive circuit

Claims (5)

[Claims] 1. A refrigerator having a control device for controlling energization of a defrost heater, the refrigerator having a counter for accumulating the operating time of the refrigerant compressor, and a conversion means for converting the number of times of opening and closing the door into time. The control device determines the defrosting start time of the cooler by the operating time of the refrigerant compressor accumulated by the counter and the opening / closing time of the door converted by the conversion means,
A defrost control device for a refrigerator, wherein a defrost heater is energized when the operation time of the refrigerant compressor has passed a predetermined time or more. 2. A defrosting device, comprising: an operation integration counter for integrating the operation time of the refrigerant compressor; a conversion means for converting the number of times of opening and closing of the door into time; and a door closing counter for measuring the time when the door is in a closed state. In a refrigerator provided with a control device for controlling energization to a heater, the control device cools by a cumulative operation time of the refrigerant compressor accumulated by the operation cumulative counter and a door opening / closing time converted by the converting means. The defrosting start time of the device is determined, and the defrosting heater is energized when the closed state of the door measured by the door close counter has passed a predetermined time or more. Defrost control device for refrigerator. 3. A temperature sensing element mounted in the freezer compartment for turning on and off the refrigerant compressor based on a signal from the temperature sensing element for sensing the temperature of the freezer compartment and mounted on the cooler for sensing the temperature of the cooler. In a refrigerator equipped with a control device for ending the defrosting of the cooler based on the signal of, the control device energizes the defrosting heater when the difference between the temperatures detected by the temperature sensing elements is larger than a predetermined value. Defrosting control device for refrigerators characterized by: 4. A temperature sensing element mounted in a freezer compartment for turning on and off a refrigerant compressor on the basis of a signal from a temperature sensing element for sensing the temperature of the freezer compartment and mounted on a cooler for sensing the temperature of the cooler. In a refrigerator provided with a control device for ending the defrosting of the cooler based on the signal of, the control device has a counter for measuring the continuous operation time of the refrigerant compressor, and the time measured by this counter is predetermined. A defrosting control device for a refrigerator, which energizes a defrosting heater when a time or more has elapsed and when a difference between temperatures detected by the both temperature sensitive elements is larger than a predetermined value. 5. A temperature sensing element mounted in a freezer compartment for turning on and off a refrigerant compressor on the basis of a signal from a temperature sensing element for sensing the temperature of the freezer compartment and mounted on a cooler for sensing the temperature of the cooler. In a refrigerator provided with a control device for ending the defrosting of the cooler based on the signal of, the control device has a continuous operation counter for measuring the continuous operation time of the refrigerant compressor, and a door for measuring the time of the closed state of the door. A closed counter, the continuous operation time measured by the continuous operation counter has passed a predetermined time or more, and the time measured by the door close counter has passed a predetermined time or more. A defrost control device for a refrigerator, which energizes a defrost heater when a difference in temperature detected by a temperature sensitive element is larger than a predetermined value.