JPS5935767A - Refrigerator - 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 is directed to a cooler which has a sensor for detecting the amount of frost adhering to the cooler and which defrosts the cooler in response to a defrosting start signal from a controller. The present invention relates to a refrigerator having a defrosting control device.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Conventional Structure and Problems The following describes a conventional defrosting control device for a cooler in a refrigerator. In FIG. 1, reference numeral 1 denotes a cooler, which consists of a cooling pipe 2 and a number of fins 3. Reference numeral 4 denotes a frost detection sensor (hereinafter referred to as sensor), which is screwed together with a holder 5 and a spacer 6 to the end plate 3'. The sensor 4 uses a piezoelectric element 7 and a diaphragm 8 to vibrate, and the diaphragm 8 uses the piezoelectric element 7 to vibrate. When frost adheres to the diaphragm 8, the vibration of the diaphragm 8 and the piezoelectric element 7 is stopped by the gravity of the frost, which is used to indirectly detect the amount of frost adhering to the cooler 1. It is something to do.

By the way, there are certain characteristics in the freezer compartment temperature and the detected amount of frost in a refrigerator equipped with the cooler 1 as described above, and there is a drawback that the detected amount of frost varies depending on the difference in the freezer compartment temperature. . This is caused by the quality of the frost that adheres to the sensor surface.When the temperature of the freezer compartment is low, the amount of moisture in the frost is small, and the restraining force exerted on the vibration of the frost sensor is small. On the other hand, when the temperature of the freezer compartment is high, the amount of moisture in the frost is large, and the binding force is large and the vibration of the frost sensor is large, so even if a relatively small amount of frost has formed, the sensor will not detect it. But sensors are for detection.

OBJECTS OF THE INVENTION The present invention aims to eliminate the above-mentioned conventional drawbacks and to make the amount of frost detected by the sensor constant regardless of the temperature inside the freezer compartment.

Structure of the Invention Namely, in order to achieve this object, the present invention utilizes the fact that the temperature inside the refrigerator has a correlation with the quality of frost adhering to the cooler, and adjusts the set temperature of the temperature controller to adjust the temperature inside the refrigerator. The detection level is linked with the variable resistor that changes the frost detection level of the sensor, increasing the detection level when the temperature inside the refrigerator is low and lowering it when it is high, so that the optimal amount of frost is generated regardless of the temperature. It is designed to enable detection.

DESCRIPTION OF THE EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1 to 4. Note that the same numbers as those in the prior art will be given the same numbers, and the explanation will be omitted.

FIG. 2 shows a sectional view of a refrigerator equipped with the cooler 1 as shown in FIG. 1 and a schematic electrical circuit diagram thereof. Refrigerator 9 is partition wall 1
0, the interior of the refrigerator is divided into an upper freezer compartment 11 and a lower refrigerator compartment 12.
It depends on the division. A cooling chamber 13 is formed in the partition wall 10 and a cooler 1 is disposed therein, and the cooler 1 constitutes a well-known refrigeration cycle together with a compressor 14, a condenser (not shown), and the like. The cooler 1 is equipped with a defrosting heater 15.
When the sensor 4 detects a predetermined amount of frost, a defrost control circuit 16 (described later) switches the changeover switch 17 from a cooling operation in which the compressor 14 is energized to a defrost operation in which the defrost heater 16 is energized. Reference numeral 18 denotes a temperature controller disposed in the freezer compartment 11, and depending on the detected temperature, the switch 18' is turned on to stop the ON-OFF FLFF 14 to maintain the desired temperature.

The temperature regulator 18 is provided with a temperature control dial 19 that can be used to change the temperature within the freezer compartment 11 to any desired temperature. This temperature control dial 19 is provided to operate in conjunction with a defrosting control circuit 160 and a variable resistor 22, which will be described later.

Next, FIG. 3 shows a specific electric circuit of the defrosting control device 16. In FIG. 3, 20 is an 8 oscillation circuit, and 21 is a frost detection circuit. The oscillation circuit 2o is a transistor TR4
, capacitors C1 to C4 and resistors R1tR2+'T
It is a Zabarov type crystal oscillator circuit composed of a variable resistor R22, and the frost detection circuit 21 is composed of transistors TR diodes D1 to D2, capacitors C6, C6, and resistors R4, R6, and a sensor When 4 detects no frost, there is a constant output at 8 points, and 1 transistor TR2 turns OFF and no detection signal is emitted at 0 points, and when frost is detected, the output at 8 points becomes 0, and the frost detection circuit 21 transistor TR2 operates and becomes 0.
It emits a detection signal from a point.

The detection level of the sensor 4 is determined by the strength of the oscillation output of the sensor 4, and the strength of the oscillation output is determined by the variable resistor 22.
The decision is determined by the resistance value. That is, the larger the resistance value, the weaker the oscillation output of the sensor 4, and therefore the lower the detection level, so that even a small amount of frost can be detected.

Next, specific interlocking means between the variable resistor 22 and the temperature control dial 19 will be explained. In FIG. 4, 19 is a temperature control dial, and 19a is a dial shaft. The dial shaft 19a is linked to the temperature regulator 18, that is,
If you turn the temperature control dial 19 counterclockwise, the freezer compartment 11
It is set so that the internal temperature becomes lower, and by turning it clockwise, it is set to become higher. Further, the variable resistor R22 has a switch 22a and a contact 22b.

22c and 22d are fixed to the dial shaft 19a via a spring 229.
It rotates in conjunction with the temperature control dial 19. That is, when the contact 22b and the switch 22a are in contact, the resistance value between a and 5 in FIG. 3 is large (RA) and the oscillation output of the sensor 4 is weak. When the contact 22c and switch 22a are in contact, the resistance value between a-5 is RB, and when the contact 22d and switch 22a are in contact, the resistance value between a-5 is RC.
is small, and the oscillation output of sensor 4 is strong. The relationship between the resistance values is RA>RB>RC.

FIG. 5 shows the relationship between the temperature inside the freezer compartment 11 and the amount of frost detected by the sensor 4 and the amount of frost when the defrost signal is generated. If the output is constant, ≦ As shown by the broken line PE, when the temperature T is low, the amount of moisture in the frost is small, so the restraint force exerted on the vibration of the cell 4 is weak, so the amount of detected frost is large, and vice versa. When the temperature is high, the binding force is strong due to the large amount of moisture, and even a small amount of frost is detected.Due to the difference in temperature T (to-13), there is a variation in the detected amount of frost PD'. However, in the present invention with the above-described configuration, the oscillation output of the sensor 4 is represented by the solid lines PA, PB,
It is variable in three stages as shown in the PC.

In other words, in the freezer compartment temperature t0 to t1 ('C) where the temperature control dial 19 is adjusted in the section A in FIG. Therefore, the oscillation output of the sensor 4 becomes weak and becomes PA, and frost detection is performed at the portion of PA shown by the solid line.

Freezer compartment temperature t1 at which the temperature control dial 19 is adjusted between losses
At ~t2 (°C), the contact 22c of the variable resistor 22 and the switch 22a are in contact, and the resistance value between a and b is RB, and the oscillation output of the sensor 4 becomes weaker and stronger to PB. This is done in the part indicated by the solid line.

Freezer room temperature t2 at which the temperature control dial 19 is adjusted between
~t3CC), the contact 22d of the variable resistor 22 and the switch 22a are in contact, and the resistance value between a and b is RC, and the oscillation output of the sensor 4 becomes even stronger, and frost detection occurs at the portion indicated by the solid line of Rc. It will be held in

As mentioned above, all the temperatures are the highest temperature t3 and the lowest temperature t. On the other hand, the variation in the amount of detected frost is limited to PD, and if the number of variable stages is increased, the variation in the amount of frost formed is the optimum amount W (C
G).

Effects of the Invention As is clear from the above description, the refrigerator of the present invention has a detection level using a variable resistor that adjusts the set temperature of the temperature controller that adjusts the internal temperature of the refrigerator and the frost amount detection level of the sensor. By linking these, the variation in the amount of frost detected by the sensor can be reduced, regardless of the temperature inside the refrigerator, in response to the fluctuation characteristics of the amount of frost detected due to differences in the quality of frost adhering to the cooler and sensor. can do.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a cooler with a frost detection sensor. Fig. 2 is a vertical cross-sectional view and a schematic electric circuit diagram of a refrigerator according to an embodiment of the present invention, Fig. 3 is a circuit diagram of a box removing and suppressing device, and Fig. 4 is a schematic diagram of the interlocking of a temperature regulator and a variable resistor. , FIG. 6 shows a comparative characteristic diagram of the freezer compartment temperature and the detected frost amount at each frost detection level. 1...Cooler, 4...Frost detection sensor (
sensor), 16...defrosting sterilization device, 18...
···air conditioner. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 Figure 3 I

Claims (1)

[Claims] A temperature controller that adjusts the temperature inside the refrigerator, a cooler that cools the inside of the refrigerator, a sensor that detects the amount of frost adhering to the cooler, and a defrost that defrosts the cooler using a defrosting start signal from this sensor. A frost control device, and a variable resistor forming a part of the defrosting control device and adjusting the frost detection level of the sensor, the temperature set by the temperature controller and the frost detection level by the variable resistor. A refrigerator that is linked so that the frost detection level increases when the temperature is low and decreases when the temperature is high.