JPH02126083A - Refrigerator - Google Patents

Abstract

PURPOSE:To prevent the chilled foodstuff from freezing due to the forced precooling effect when the outside temperature is low and prevent the frozen foodstuff from deteriorating by controlling the temperature increase during the defrosting when the outside temperature is high by changing the forced precooling time in accordance with the outside temperature so that the forced precooling time may be shorter when the outside temperature is lower than the precooling time at the time of high ambient temperatures. CONSTITUTION:When the ambient temperature is high than a predetermined value, the resistance RTH of an ambient temperature thermistor 27 becomes low to cause the output of a comparator 28 to become 'H', and the input to an AND circuit on the side of the comparator 28 becomes 'L' through an inverter circuit 32. The precool timer 20 is then selected to cause the compressor 12 and fan 9 to be operated for a forced precooling. On the other hand, when the ambient temperature is lower than a predetermined value, the resistance R'TH becomes high to cause the output of the comparator to become 'L', and a precool timer 30 is selected. Therefore, the 'H' signal is outputted from the (h) output of the timer 30 for a time period shorter than the (e) output of the timer 20, allowing a forced precooling for a time period shorter than that which is performed under high ambient temperature conditions.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a refrigerator equipped with a defrosting function that performs forced precooling and defrosting operation.

BACKGROUND OF THE INVENTION In order to prevent the temperature rise inside the refrigerator due to defrosting operation, modern refrigerators drive the compressor in advance to forcibly perform cooling operation for a certain period of time when the defrosting period arrives to compensate for the temperature rise. It is common practice to cool the inside of the refrigerator in advance and then perform a defrosting operation to prevent a rise in temperature inside the refrigerator due to defrosting. A conventional example will be described below with reference to FIGS. 3 and 4.

1 is the refrigerator body, 2 is an outer box, 3 is an inner box, and 4 is a heat insulating material. 6 is a freezer compartment, 6 is a refrigerator compartment, and γ is a cooling compartment. The cooling chamber 7 includes a cooler 8 and a fan 9 for blowing cold air to the freezing chamber 5 and the refrigerator chamber 6.

Further, a defrosting heater 10 is attached to the cooler 8 to remove frost from the cooler 8. There is a duct 11 between the freezer compartment 6 and the refrigerator compartment 6, through which cold air flows into the compartment. A thermistor 13 is installed in the freezer compartment 5 to detect the temperature inside the freezer compartment 6 in order to control the operation and stop of the compressor 12 of a refrigeration cycle (not shown).

Next, the electric circuit will be explained. The fan 9 and the compressor 12 are connected in parallel, connected to a relay contact 14, and then connected to a power source. In addition, the defrosting heater 10
/- After being connected to contact 16, it is connected to the power supply. Reference numeral 16 denotes a freezing chamber temperature control device, which includes a ZARMISTER 13 provided in the freezing chamber 6, resistors R1, R2, R3, and a comparator 1. A defrosting control device 18 includes an integration timer 19 and a pre-cool timer 20. The output of the comparator 17 is the integration timer 19 (7).
The b output of the single integration timer 19 connected to the a input is connected to one input of the OR circuit 21, and the C output is connected to the d input of the pre-cool timer 20. Precool timer 2
The C output of 0 is connected to the other input terminal of the OR circuit 21, and the f output is connected to the base of the transistor 22. An absorption relay coil 23 for opening and closing the relay contact 16 is connected to the collector of the transistor 22.

The output of the OR circuit 21 is connected to the base of a transistor 24, and the collector thereof is connected to an absorption relay coil 25 for opening and closing the relay contact 14. Here, the integration timer 19 and pre-cool timer 2 of the defrosting control device 18
0 will be explained and explained. Product 'l timer 19 has input a and b
and C output, and the Hfgh signal is below “H” at the a input.
When a low signal (hereinafter referred to as "L") is inputted to the b output, an "H" signal is outputted, and when a low signal (hereinafter referred to as "L") is inputted to the a input, an "L" signal is outputted from the b output. In addition, input "a"
H” hours are accumulated and the prescribed settlement time (e.g. 81 hours)
When this happens, a single pulse of "H" is output from the C output.

Precool timer 2Q has d input and θ and f outputs,
When a single pulse of "H" signal is input to the d input, a "H" signal is output from the C output for a certain period of time (for example, 40 minutes),
After that, it is configured to output an "H" signal for a certain period of time (for example, 20 minutes).

In such a configuration, under normal conditions, the temperature of the freezer compartment 5 is higher than the predetermined fm.
If H is small (-), the output of comparator 17 becomes “H”
Output a signal. The H" signal is input to the a input of the product p timer 19, H"1t7 is output from the output, the output of the OR circuit 21 also becomes 'H', and the transistor 24 is turned on.
-jru. Therefore, four relay coils 25 are connected. Then, the relay contact 14 is turned on, the compressor 12 and the fan 9 are energized and operated, the cooler 8 performs a cooling action, and the fan 9 forces iM air into the freezer compartment 6 to perform a cooling action. Thereafter, when the freezer compartment 5 is cooled to a predetermined temperature K, the resistance value RTH of the ZARMISTER 13 becomes sharper, the comparator 17 outputs a signal "■", and the integration timer 19 output b also becomes "L". Since the C output of the pre-cool timer 20 is also 1L'', the output of the OR circuit 21 is also ``L'', and the transistor 24 is turned 0FFj, thereby cutting off conduction to the relay coil 26, turning off the relay contact 14, and turning off the compressor 1.
2. The fan 9 stops and the cooling action also stops. Thereafter, this action is repeated to perform the normal cooling action.Next, when the integration timer 19 has integrated for a predetermined time, a one-pulse "H" signal is output from the C output and the pre-cool timer 2 is activated.
It is input to the d input of 0. Therefore, pre-cool timer 20
An "H" signal is output for a certain period of time from the C output of the OR circuit 21, regardless of the output state of the comparator 17.
The signal becomes "H" and the transistor 24 is turned on. The compressor 12. Fan 9 is strong! 1jll operation, 6 freezer compartments
1. Next, after a "H" signal is output from the C output of the pre-cool timer 20 for a certain period of time, a "H" signal is output from the f output, and the transistor 22 turns ON to the relay coil. 23 is passed through 26, the relay contact 15 is turned on, and the bamboo removal heater 10 is energized to remove the frost attached to the cooler 8. That is, when the integration timer 19 integrates for a predetermined period of time, the compressor 12. The fan 9 is operated to perform a defrosting action after forced cooling for a certain period of time. Therefore, by performing a forced pre-cooling process before defrosting, the temperature inside the freezer compartment 6 is lowered, thereby suppressing the rise in temperature inside the freezing compartment 6 when frost occurs, and controlling the temperature to prevent deterioration of frozen foods. ing.

Problem to be Solved by the Invention However, in such a configuration, when the outside temperature is low, an H'' signal is output from the C output of the pre-cool timer 2o, and the compressor 12 and fan 9 are operated.
If the pre-cooling time is long, the temperature in the refrigerator compartment 6 will drop to 0° C. or lower at low outside temperatures where the influence of the outside air temperature is small, freezing the refrigerated food and causing food deterioration. On the other hand, if the forced pre-cooling time is also shortened, there is a problem that when the outside air temperature is high, forced pre-cooling will not cool the food sufficiently and the temperature rise during defrosting cannot be suppressed, causing deterioration of the frozen food. Ta.

The present invention solves the above-mentioned problems, and allows freezing of refrigerated foods by forced pre-cooling at low outside temperatures,
The purpose is to suppress temperature rise during cutting at high temperatures, prevent deterioration of frozen foods, and optimize forced pre-cooling time.

Means for Solving the Problems In order to solve the above problems, the refrigerator of the present invention changes the forced pre-cooling time depending on the outside temperature, and the forced pre-cooling time for low outside temperatures is shorter than the forced pre-cooling time for high outside temperatures. It is designed to make it shorter.

Effect: With the above-described configuration, the present invention shortens the forced precooling time more quickly when the outside air temperature is lower than the set temperature than when the outside air temperature is high, and the forced precooling is performed when the temperature of the refrigerator compartment becomes less than Q℃. To terminate the cooling action and prevent refrigerated foods from freezing.

Embodiment Hereinafter, an embodiment of the refrigerator of the present invention will be described with reference to FIGS. 1 and 2. In addition, the same reference numerals are attached to the same configurations as in the prior art, and detailed explanation thereof will be omitted. Reference numeral 26 denotes an outside air temperature detection device, which includes an outside air temperature thermistor 2 attached to a part of the outer shell of the refrigerator body 1, resistors R4, R5, R6, and a comparator 28. Reference numeral 29 is a defrosting device equipped with an integration timer 19° and pre-cool timers 2o and 3o. To explain the pre-cool timer 3o, it has a q input and h and i outputs, and the role of each input/output is the same as the d input, e, and f output of the pre-cool timer 20, but the “H” from the h output The time of the signal is shorter than the "H" signal time of the C output of the pre-cool timer 20 (for example, the C output is 40 minutes while the H output is 20 minutes). The "H" signal time of the i output of the pre-cool timer 30 is the same as the "H" signal time of the f output of the pre-cool timer 2o. One of the outputs of the comparator 28 is connected to one input of an AND circuit 31, and the other output of the comparator 28 is connected to one input of an AND circuit 33 via an inverter circuit 32. Also, AND circuits 31 and 33
The C output of the integration timer 19 is connected to the other input of both. Next, the output of the AND circuit 31 is connected to the d input of the pre-cool timer 2o, and the output of the AND circuit 33 is connected to the q input of the pre-cool timer 3°. The e and h outputs of pre-cool timers 2° and 3o are both connected to the OR circuit 34.
The b output of the integration timer 19 is connected to the remaining input of the OR circuit 34.

The output of OR circuit 34 is connected to the pace of transistor 24. Next, pre-cool timers 20 and 30!
and i output are both input to the OR circuit 35, and the OR circuit 3
The output of 5 is connected to the base of transistor 22.

In this configuration, when the integration timer 19 integrates for a predetermined period of time, it outputs a one-pulse "H" signal from the C output. At that time, if the outside temperature is higher than the predetermined value, the resistance value "TH" of the outside temperature thermistor 27 becomes small and the comparator 28
output becomes "H", the input on the comparator 2B side of the AND circuit 31 is "H", and the input on the comparator side of the AND circuit 33 becomes "L" via the inverter circuit 32. “H” of One Pulse
In response to the signal, the output of the AND circuit 31 is one pulse “H”
Therefore, the output of the AND circuit 33 remains in the "@L" state. Therefore, the pre-cool timer 2Q is selected, and the "H" output is output for a certain period of time from the C output, and the output of the OR circuit 34 is also "@L".
The transistor 24 turns on, and the compressor 12 and fan 9 operate to perform forced precooling. After the C output of the pre-cool timer 20 outputs an "H" signal, the f output outputs an "H" signal. , the output of the OR circuit 36 becomes 1H'', the transistor 22 is turned on, and the defrosting heater 10 is energized.
Remove the frost from the cooler 8.

Next, when the outside air temperature is lower than the predetermined value, the resistance value "rH" of the outside temperature thermistor 27 increases and the comparator 28
The output of the comparator 2 of the AND circuit 31 becomes L”.
The input on the 8 side is also “L”, and the comparator 2 of the AND circuit 33
The input on the 8 side becomes H'' through the inverter circuit 32,
Pre-cool timer 30 is selected. Therefore, from the h output of the pre-cool timer 30, an "H" signal is output for a shorter time than the e output of the pre-cool timer 20, and the output of the OR circuit 34 also becomes "H", causing the transistor 24 to turn ON.
, compressor 12. The fan 9 operates, and forced precooling is performed in a shorter time than when the outside air temperature is high. After the "H" signal is output from the h output of the bricoeur timer 30, the "H" signal is output from the i output, the output of the OR circuit 35 becomes "H", the υ transistor 22 is turned on, and the defrosting heater 1Q is energized. ,
Remove the cooler 8 sheath.

Therefore, the forced pre-cooling time is selected depending on the outside temperature, and by making the time at low outside temperature shorter than that at high outside temperature, the defrosting action will begin before the temperature of the refrigerator compartment falls below 0°C. , can prevent food from freezing. In addition, since the heat absorption load on the refrigerator body 1 is also reduced under low outside air temperature, the evaporation temperature of the cooler 8 is also sufficiently reduced.
Even if the forced pre-cooling time is shortened, the intended purpose of reducing the indoor temperature of the freezer compartment etc. before defrosting and preventing a temperature rise during defrosting can be fully achieved.

According to the refrigerator of the present invention, the effect of the invention is as follows:
By selecting the forced pre-cooling time and selecting a shorter time when the outside temperature is low, the food in the refrigerator compartment is prevented from freezing and the temperature in the freezer compartment is prevented from rising. In addition, by selecting a long time when the outside temperature is high, the temperature of the freezer compartment can be sufficiently lowered during forced precooling, and an increase in cold temperature during defrosting can be suppressed.

[Brief explanation of the drawing]

FIG. 1 is an electric circuit diagram of a refrigerator showing an embodiment of the present invention;
FIG. 2 is a sectional view of the same refrigerator, FIG. 3 is an electric circuit diagram of a conventional refrigerator, and FIG. 4 is a sectional view of the same refrigerator. 1... Refrigerator, 6... Freezer, 6...
...Refrigerating room, 8...Cooler, 1o...
・Defrost heater, 12...Compressor, 16...
... Freezer room temperature control device, 27 ... Outside temperature thermistor, 29 ... Aphrodisiac control device. Name of agent: Patent attorney Shigetaka Awano and 1 other person1
・・・- 6-・ 8-・ : 9 K fM : 9 Freezer; Mi K 嘗 ! ll'Ib Kasumi Den C-

Claims (1)

[Claims] A freezer compartment, a refrigerator compartment, a freezer compartment temperature control device that detects the temperature in the freezer compartment and controls the operation of the compressor of the refrigeration cycle, and integrates the operating time of the compressor and controls the temperature for a certain period of time after the completion of the integration. The defrost control device includes a defrost control device that causes the compressor to perform a forced pre-cooling operation and then energizes a defrost heater that melts the frost in the cooler of the refrigeration cycle, and an outside temperature thermistor that detects the outside temperature, and the defrost control device includes: The refrigerator includes means for shortening the forced precooling operation time of the compressor before defrosting when the outside temperature thermistor detects a low outside temperature.