KR19990053417A - How to check the defrost sensor of the refrigerator - Google Patents

Abstract

The present invention checks the defects of the defrost sensor, not the open or short fault of the refrigerator defrost sensor, based on the rising width of the internal temperature and the cycle of the defrost cycle during normal operation of the refrigerator. The present invention relates to a method of checking a defrost sensor of a refrigerator for improving its performance and maintainability.

The present invention for this purpose, in the defect check method of the defrost sensor for detecting the defrost temperature during the defrost of the refrigerator evaporator, determining the number of cycles before the start of the defrost of the normal operation cycle (cycle) of the refrigerator; Checking the internal temperature of the refrigerator and the cycle period before the start of defrosting, if it is determined a few cycles before the start of defrosting in the step; When the defrosting operation is performed, determining whether the defrosting start and the defrosting end are normally achieved; If an abnormal defrosting operation occurs in the step, counting once as a defrost operation failure, if the defrost operation failure is counted more than two times, forcibly defrosting for a predetermined time and warning that the defrost sensor is a characteristic defect It is done.

Description

How to check the defrost sensor of the refrigerator

The present invention relates to a method for checking a defrosting sensor defect of a refrigerator, and more particularly, a rise in temperature and a defrost cycle of a high temperature inside the refrigerator during normal operation of the defrost sensor, which is not an open or short fault of the defrosting sensor. The method of the present invention relates to a method of checking a defrost sensor of a refrigerator for improving the after-sales and maintenance of the refrigerator by checking the cycle.

As is well known, in the evaporator of a refrigerator, cooling is performed by the heat of evaporation which the liquid refrigerant takes from the surroundings when it evaporates. At this time, the frost is pinched by the freezing of moisture around the evaporator. In such a castle, it is necessary to remove the frost because it is a main factor that greatly reduces the evaporator efficiency. Therefore, the refrigerator is provided with a defrost heater which is electrically heated to melt frost attached to the evaporator, and means for appropriately controlling the defrost heater.

FIG. 1 schematically shows an example of a hardware circuit for defrosting in a general refrigerator. Referring to FIG. 1, reference numeral 1 is a defrost heater installed in an evaporator, 2 is a relay for intermitting a power applied to the defrost heater, 3 is overheating of the defrost heater 1 or an overcurrent to the defrost heater. The temperature fuse to prevent the failure of the heater 1 by the 10, the microcomputer for the defrost control of the refrigerator and the refrigerator, 100 is a defrost sensor installed in the evaporator to sense the temperature, reference numeral IV is the microcomputer of the Inverter to excite the coil of the relay (2) according to the control to turn the contact on / off, R1 is a voltage distribution resistor that is connected in series with the defrost sensor 100 to distribute the voltage, R2 is applied to the microcomputer 10 A current limiting resistor, C, which limits the current, is a capacitor that removes noise that can be applied to the microcomputer 10. Here, the defrost sensor 100 is a thermistor having a property that the resistance of the defrosting sensor 100 is high when the temperature is high, and the resistance of the defrosting sensor is large when the temperature is low. In FIG. 1, there is one defrost sensor 100, but when there are two evaporators, for example, two defrost sensors are installed when the evaporator for a refrigerator compartment and the evaporator for a freezer compartment are installed independently. Will be self explanatory. The same applies to the following.

In the refrigerator defroster configured as described above, since the resistance value of the defrost sensor 100 varies according to temperature, the signal input to the microcomputer 10 also changes. The microcomputer 10 generates heat of the heater 1 according to a preset defrosting condition to perform defrosting of the evaporator. That is, when the above defrosting condition is reached, the microcomputer 10 applies a high signal to the inverter IV to excite the coil of the relay 2 so that its contact is turned on. When the relay 2 contact is turned on, power is applied to the heater 1. When power is applied to the heater 1, the heater 1 generates heat, and defrosting is performed by the heater heat. During the defrosting, the temperature of the heater 1 increases, which is detected by the defrost sensor 100 and input to the microcomputer 10. When the heating temperature of the heater 1 sensed by the defrost sensor 100 is greater than or equal to a predetermined temperature, the microcomputer 10 terminates the defrosting by preventing power from being applied to the heater 1.

In the defrosting operation of the refrigerator as described above, if the defrost sensor 100 causes a breakdown as shown in FIG. 2A, the corresponding port of the microcomputer 10 is related to the temperature of the heater 1, that is, the temperature of the evaporator. The high signal (5 volt signal) is continuously input without any change. In addition, when the defrost sensor 100 causes a short circuit fault as shown in FIG. 2B, a low signal (0 volt signal) is applied to the corresponding port of the microcomputer 10 regardless of the temperature of the heater 1, that is, the temperature of the evaporator. Is still input. As such, when a high signal or a low signal is continuously input to a corresponding port of the microcomputer 10 associated with the defrost sensor 100, the microcomputer 10 determines that a disconnection failure or a short circuit failure has occurred in the defrost sensor 100. It is to give an alarm to fix the problem, or to make a temporary forced defrost for a certain time.

That is, in the conventional method of checking the defrost sensor failure of the refrigerator, as shown in FIG. 3, the defrost sensor 100 is checked for open failure, and if the defrost sensor 100 is defective, it is forced for a predetermined time. Defrost is to be made (S1) (S3). If the defrosting sensor 100 is not disconnected, the defrosting sensor 100 checks whether the short circuit is short and if the defrosting sensor 100 is short-circuited, similarly, forced defrosting is performed for a predetermined time (S2) ( S3).

However, in the defrosting operation of the refrigerator as described above, the resistance value of the sensor is not changed, corresponding to the ambient temperature, rather than an open or short failure of the defrost sensor 100, and is always constant. When the characteristic defect of the sensor having a resistance value occurs, there is a problem that can not be repaired in the end because there is no basis for judgment on the characteristic defect of the sensor.

For example, if the defrost sensor has a characteristic defect at high temperature in the defrosting operation of the refrigerator, defrost heating is not performed properly, so much frost is generated in the evaporator. There was a problem that occurred. In addition, there is a problem that excessive deterioration of the internal temperature may occur due to excessive defrost heating when the defrost sensor has a characteristic defect at a low temperature in the defrosting operation of the refrigerator.

The present invention was created in order to solve the above problems, and it is not an open or short fault of the defrost sensor, but a defect in the characteristics of the defrost sensor is described. It is an object of the present invention to provide a method of checking a defrosting sensor defect of a refrigerator to improve the A / S and maintenance of the refrigerator by checking the basis.

1 is a schematic hardware circuit diagram of a refrigerator for implementing a defrosting method of a general refrigerator;

2A and 2B are circuit diagrams illustrating types of open and short faults occurring in the defrost sensor, respectively.

3 is a flowchart of a method for checking a defrost sensor failure of a conventional refrigerator;

Figure 4 is a flow chart of the defrost sensor failure checking method of the refrigerator according to the present invention.

<Description of the symbols for the main parts of the drawings>

1: defrost heater 3: temperature fuse

10 microcomputer 100 defrost sensor

200: high temperature sensor

Defrost sensor defect check method of the refrigerator according to the present invention to achieve the above object,

In the defect check method of the defrost sensor for detecting the defrost temperature during the defrost of the refrigerator evaporator,

Determining how many cycles before the start of defrosting during a normal operation cycle of the refrigerator;

Checking the internal temperature of the refrigerator and the cycle period before the start of defrosting, if it is determined a few cycles before the start of defrosting in the step;

When the defrosting operation is performed, determining whether the defrosting start and the defrosting end are normally achieved;

If abnormal defrosting operation occurs in this step, counting once as a defrost operation failure, if the defrost operation failure is counted more than two times, including the step of forced defrosting for a predetermined time and warning that the defrost sensor is a characteristic defect It has its features.

In a preferred embodiment of the present invention, the several cycles are 2-3 cycles.

In a preferred embodiment of the present invention, the deficient characteristic of the defrost sensor always has a resistance value corresponding to a low temperature regardless of the ambient temperature, or a state having a resistance value corresponding to a high temperature always regardless of the ambient temperature to be.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the defrost sensor failure checking method of the refrigerator according to the present invention. For the convenience of description, the same reference numerals are used for constituent members that have the same function as the constituent members used in the prior art.

4 is a flowchart illustrating a method for checking a defrost sensor failure of the refrigerator of the present invention. It will be apparent to those skilled in the art that the flowchart algorithm of the present invention checking method shown in FIG. 4 is programmed and stored in the microcomputer 10 for execution.

Referring to FIG. 4, in the method of checking a defrost sensor of a refrigerator of the present invention, determining whether a defrosting start is performed a predetermined number of times before the start of defrosting, for example, 2 to 3 cycles during a normal operation cycle of the refrigerator ( S10); When the start of defrosting is performed after the above 2-3 cycles, checking the internal temperature of the refrigerator and the operation cycle period of the refrigerator until the start of defrosting (S20); When the defrosting operation is performed after step S20, determining whether defrosting start and defrosting have been normally performed (S30) (S40); If the abnormal defrosting operation occurs in step S40, counting once as a defrost operation failure (S50) (S80), if the defrost operation failure counted more than two times forcible defrosting for a predetermined time and defrost sensor 100 is a characteristic defect It comprises a warning step (S60) (S70). Defrost sensor 100 characteristic failure in step S70 is always a state having a resistance value corresponding to a low temperature regardless of the ambient temperature (low temperature characteristic failure), or always having a resistance value corresponding to a high temperature regardless of the ambient temperature State (high temperature characteristic defect).

An operation of the defrost sensor failure checking method of the present invention refrigerator configured as described above will be described with reference to FIGS. 1 and 4.

First, the microcomputer 10 observes the temperature of the internal temperature sensor 200 (FIG. 1) of the freezer compartment or the refrigerating compartment from about 2-3 cycles before reaching the defrosting point according to the defrosting period, thereby increasing the width of the internal temperature during normal operation. And the cycle of the operation cycle is recorded (S10) (S20). When the defrost is started in such a state (S30), it is determined whether the defrost start and the defrost end is normally performed (S40). If the defrosting start and end defrosting is not normally performed in step S40, the microcomputer 10 checks how many times there is such a defrost operation failure (S50). If the defrost operation is two or more times in the step S50, the microcomputer 10 allows forced defrosting for a predetermined time (S60). In addition, it warns that the defrosting operation failure is due to the characteristic defect of the defrost sensor 100 (S70).

If the defrost operation failure is not more than two times in step S50, the microcomputer 10 counts and stores the defrost operation failure once (S80). The counting of the defrost operation failure one or more times in this way is because the defrost operation failure may occur in some cases even if the defrost sensor 100 is not a characteristic defect.

In step S70, a warning of a characteristic defect of the defrost sensor 100 may be implemented in various ways. For example, when there is a special key input during A / S, the LED of the refrigerator control panel (not shown) is turned on or Alternatively, a warning buzzer can be used to signal a defect.

As described above, the present invention monitors the temperature of the internal temperature sensor 200 of the freezer compartment or the refrigerating chamber from about 2-3 cycles before reaching the defrosting point according to the defrosting cycle, thereby increasing the width of the internal temperature during the normal operation and the cycle of the cycle. After this, it is necessary to make a normal defrost by deciding whether this defrost should be normally performed before defrosting every defrost with each defrost, and if the defrosting occurs more than twice, the defrost sensor 100 Even if there is no disconnection / short circuit fault, it will be treated as defective.

As described above, the defrosting sensor failure checking method of the refrigerator of the present invention is characterized in that the deterioration of the characteristics of the defrosting sensor is not an open or short fault of the defrosting sensor. By checking based on this, the A / S and maintenance properties of the refrigerator are improved.

Claims (4)

In the defect check method of the defrost sensor for detecting the defrost temperature during the defrost of the refrigerator evaporator, Determining how many cycles before the start of defrosting during a normal operation cycle of the refrigerator; Checking the internal temperature of the refrigerator and the cycle period before the start of defrosting, if it is determined a few cycles before the start of defrosting in the step; When the defrosting operation is performed, determining whether the defrosting start and the defrosting end are normally achieved; If an abnormal defrosting operation occurs in the step, counting once as a defrost operation failure, if the defrost operation failure is counted more than two times, forcibly defrosting for a predetermined time and warning that the defrost sensor is a characteristic defect How to check the defrost sensor of the refrigerator. The method of claim 1, wherein the several cycles are 2-3 cycles. The method of claim 1, wherein the deficient characteristic of the defrost sensor has a resistance value corresponding to a low temperature at all times regardless of the ambient temperature. The method of claim 1, wherein the defective characteristic of the defrost sensor is a state in which a resistance value corresponding to a high temperature is always maintained regardless of the ambient temperature.