GB2180962A

GB2180962A - Controlling device for a refrigerator

Info

Publication number: GB2180962A
Application number: GB08622955A
Authority: GB
Inventors: Masaya Itagaki
Original assignee: Mitsubishi Electric Corp
Current assignee: Mitsubishi Electric Corp
Priority date: 1985-09-25
Filing date: 1986-09-24
Publication date: 1987-04-08
Also published as: CN86105354A; HK34290A; AU6307786A; AU586500B2; CN1010883B; CN1004726B; GB8622955D0; SG4990G; GB2180962B; CN1040676A

Abstract

A controlling device for a refrigerator which can cool food rapidly by a simple operation when it is stored in a large amount into a refrigerating chamber and which can maintain it automatically at an optimum temperature. The device comprises a quick refrigeration switch 12, and controlling means is for compulsorily lowering a preset temperature within the refrigerator to perform quick refrigerating operation of the refrigerator. The quick refrigerating operation thus started is stopped after a predetermined period of time or a predetermined number of opening and closing motions of a damper which regulates the supply of cold air to the refrigerator. The device may further include an external air temperature detector 13 so that the preset temperature may be lowered in response to the external air temperature. <IMAGE>

Description

SPECIFICATION Controlling device for a refrigerator Background ofthe invention This invention relates to a controlling devicefora refrigerator ofthe type wherein a damper is opened and closed to quickly refrigerate a refrigerating chamber of the refrigerator.

Atypical one of conventional controlling devices for a refrigerator includes a refrigerator body in which a plurality of chambers including a freezing chamber, a refrigerating chamber and a vegetable chamber are formed by partitioning the inside ofthe refrigerator with the refrigerating chamber located below the freezing chamber and above the vegetable chamber. A compressor is located at a lower portion of the body. A cooler is located in the interior ofthe freezingchamberanda blower is located abovethe cooler and connected to be driven by an electric motor. An air course extends from the rear ofthe coolertotherefrigerating chamber, and athermal damper of the gas type including a body and a baffle is located neara blow-out portofthe air course to the refrigerating chamber.

In operation, whilethe compressor is operating, also the blower is rotating so that cooling air having passed through the cooler is blown out directly into the freezing chamber and also into the air course. In this instance, if the temperature within the refrigerating chamber is higherthan a preset level, then the thermal damper will detect itand open the baffleto allowa large amount of cooling airto blow out into the refrigerating chamberto cool within the re frigerating chamber. On the contrary, if thetem- peraturewithin the refrigerating chamber is lower than the preset level, the baffle of the damper is controlled to be a little closed to decrease the amount of cooling airto be blown out into the refrigerating chamber.In such a controlling manner, the tem- perature within the refrigerating chamber is held to the presettemperature.

Such a conventional controlling device for a refrigerator as described above has various problems: since the amount of cooling air blown into therefrigerating chamber is regulated to control the temperature within the refrigerating chamber, even when a large amount offood is additionally stored into the refrigerating chamber, the refrigerating speed cannot be raised as it is and hence the preset condition ofthe damper must be changed over to raise the refrigerating speed; however, in order to raisethe refrigerating speed, the thermal damper must be set to "strong", but if the thermal damper is left set to "strong", food stored in the refrigeratorwill become frozen, and therefore, the thermal damper must be re-set to its normal condition after it has been once setts "strong".

Summary ofthe invention It is an object of the present invention to provide a controlling device for a refrigerator wherein, when a large amount of food is additionally stored into a refrigerating chamber, the food can be cooled rapidly by a simple operation.

It is another object ofthe invention to provide a controlling device for a refrigeratorwherein a large amount of food can be cooled rapidly and after it has been cooled, it can be maintained automaticallyatan optimum temperature.

It is a further object of the invention to provide a controlling device for a refrigerator which eliminates a bad influence of a change ofthetemperature ofthe external air on stored food in the refrigerator.

According to one aspect ofthe present invention, a controlling device for a refrigerator of the type wherein a damper is opened or closed to control the amount of supply of cooling airto regulatethetem- perature within the refrigerator comprises a quick refrigeration switch, and controlling means operable in response to operation of the switch for compulsorily lowering a preset temperature within the refrigerator to perform quick refrigerating operation ofthe refrigerator.

Since the quick refrigeration switch is provided, when a large amount of food is stored in the refrigerator, the damper is controlled automatically by operation ofthe switch so that quick refrigerating operation of the refrigerator is performed to cool the stored food quickly.

Thus, since quick refrigerating operation is performed compulsorily in response to operation of the quick refrigeration switch, even when a large amount of food is stored in the refrigerator, quick refrigeration can be effected by a simple operation, resulting in improvement in operability ofthesystem.

According to another aspect of the invention, a controlling device for a refrigerator ofthetype wherein cooling air cooled by a cooler is blasted into a refrigerating chamber by a blower and a damper is opened and closed to regulatethe amount of air blasted into the refrigerating chamber in response to a temperature within the refrigerating chamberto con trol the temperature within the refrigerating chamber to a presettemperature comprises a quick refrigeration switch, an external air temperature detector for detecting a temperature of the external air,a preset temperature lowering means operable in response to operation of the quick refrigeration switch for lowering the preset temperature for the refrigerating chamber in resposne to an output ofthe external air temperature detector, means for detecting eitherthat the number of opening and closing motions of the damper reaches a predetermined value orthatthe time ofthe quick refrigerating operation reaches a predetermined time during quick refrigerating operation of the refrigerator started in response to lower ofthe presettemperature, and a quick refrigeration stopping means operable in response to a detection signal from the detecting means for developing an instruction to stop the quick refrigerating operation ofthe refrigerator.

Thus, if the quick refrigeration switch is aperated, the presettemperature for the refrigerating chamber is lowered in response to a temperature of the external airto cause quick refrigerating operation ofthe refrigeratorto lower the tem peratu re within the re- frigerating chamber, and then if predetermined requirements are met during the quick refrigerating operation, the quick refrigerating operation of there frigerator is stopped.

Thus, after starting the quick refrigerating operation the quick refrigerating operation of the refrigerator is stopped either when the number of opening and closing motions reaches a predetermined fixed value orwhen the time of the quick refrigerating operation reaches a predetermined fixed time during the quick refrigerating operation. Accordingly, even when a large amount offood is additionally stored into the refrigerating chamber, the food can be cooled rapidly, and that overcooling when the external airtemperature is too low can be prevented.

Brief descriptíon ofthe drawing Figure lisa block diagram showing an embodiment of a controlling device for a refrigerator according to the present invention; Figure2 is a cross sectional view of a refrigeratorto which the controlling device according to the invention is applied; Figure3isacircuitdiagram illustrating acircuit construction of the controlling device of Figure 1; Figure 4 is a block diagram of a microcomputer of Figure 3; Figure 5is a flowchart illustrating an entire flow of operations ofthe controlling device of Figure 1; Figures 6, 7and 8are flowcharts showing details of a temperature input taking in routine, an inputjudg- ing routine and a damper outputting routine of Figure 5, respectively; and Figure 9is a vertical sectional view showing a typical one of conventional controlling devices for a refrigerator.

Description of the preferred embodiment At first, a typical one of conventional controlling devices for a refrigerator is described with reference to Figure 9. A refrigerator shown includes a refrigera tor body 1 inwhicha pluralityofstoragechambers including a freezing chamber 2, a refrigerating chamber3 and a vegetable chamber4 are formed by partitioning the inside thereof. A compressor 5 for compressing a cooling medium is located at a lower portion of the refrigerator body 1, and a cooler 6 is located in a cooler chamber partitioned in the interior ofthe freezing chamber 2.A blower7 is located abovethe cooler 6 and connected to be driven byan electric motor an air course or blow-out duct 9for supplying cooling air into the refrigerating chamber 3 extends from the rear of the cooler 6 to the refrigerating chamber 3, and athermal damper 10 of the gas type for regulating the temperature within the refrigerating chamber3 is located near a blowout port ofthe air course 9 to the refrigerating chamber 3. The thermal damper 10 includes a body 10a and a baffle 10b.

Now, an embodimentofacontrolling devicefora refrigerator according to the present invention will be described in detail with reference to Figures 1 to 8.

At first, a refrigerator to which a controlling device according to the invention is applied will be described with referenceto Figure 2. In Figure 2, reference numerals 1 to 9 denote like or equivalent parts to those of the conventional device described above with reference to Figure 9. A refrigerator shown in Figure 2 includes a refrigerator body 1 in which a freezing chamber 2, a refrigerating chamber3 and a vegetable chamber 4 are formed with the refrigerating chamber3 located belowthefreezing chamber2 and above the vegetable chamber4. A compressor5 is located at a lower portion of the refrigerator body 1 and a cooler6 is located in the interiorofthefreezing chamber 2. Afan 7 is located above the cooler 6 and connected to be driven by an electric motor8. A blow-out duct or air course 9 extends downwardly from behind the cooler 6.An electrically driven damper21 having a baffle 21a is located in an opposing relationship at a blow-out port ofthe air course 9 to the refrigerating chamber3 and is mounted for opening and closing movement to allow and interrupt passage of cooling air thereby. A refrigerating chambertemperature detector 14 such as a thermistor for detecting a temperature within the refrigerating chamber3 is located nearthedamper21.Acon- trolling device 22 is accommodated in an upper rear portion ofthe refrigerator body 1, and an operation panel 23 is mounted on a door 24 forthe freezing chamber 2.The operation panel 23 has thereon a quick refrigeration switch 12, a quick refrigeration display lamp 18 composed of a light emitting diode or the like, and a variable resistor 25 for setting atemperatureforthe refrigerating chamber3.

Referring nowto Figure 1 which is a blockdiagram showing general construction of an entire controlling device for a refrigerator. The controlling device includes the quick refrigeration switch 12, an external airtemperature detector 13 and the refrigerating chambertemperature detector 14.In responseto a signal received from the external temperature detector 13, a preset temperature for the refrigerating chamber3 is lowered bya preset temperature lowering means 15which receives an output of the quick refrigeration switch 12, and the damper 21 is opened or closed by means of a damper relay driving circuit 18 in response to outputs of the presettemperature lowering means 15 and the refrigerating chamber temperature detector 14 under control of a controlling means 1 6to control thetemperature ofthe refrigerating chamber 3 to a thus lower presettem- perature. Simultaneously, a quick refrigeration display lamp 18 is lit.When the number of opening and closing motions ofthe damper reaches a predetermined value, a quick refrigeration stopping means 19 is rendered operative to close the damper 21 byway ofthe damper relay driving circuit 17 and the display lamp 18 is extinguished.

Referring now to Figure 3 which is a circuit diagram of an electric circuit of the controlling device of Figure 1, the controlling device 22 includes a micro computer26which in turn includesacentral processing unit (CPU) 26A, a memory26B, an inputcircuit 26C and an output circuit 26D, as shown in a block diagram of Figure 4. Connected to the inputcir- cuit 26C are the quick refrigeration switch 12,the there- frigerating chambertemperature setting variable re sistor 25, the refrigerating chamber temperature det- ector 14, the external airtemperature detector 13, and resistors 27 to 29. Meanwhile, connected to the output circuit 26D are the damper relay driving circuit 17, a compressor relay driving circuit30 and the dis play lamp 18via a current limiting resistor 31.The resistors 27 to 29 are voltage dividing resistors for the variable resistor 25, the refrigerating chamber temperature detector 14 and the external temperature detector 13, respectively, and are provided for taking a refrigerating chamber preset te m- perature, a refrigerating chambertemperature and an external air temperature into the microcomputer 26. Where the external airtemperature detector 13 is omitted, the resistor may be omitted and the resis- tor 27 may be connected at an end remote from the variable resistor 25 to an end ofthe resistor 28 remote from the refrigerating chambertemperature detector 14.A compressor relay 32 is connected to the compressor relay driving circuit 30. When the compressor relay 32 is energized a contact 32a thereof is closed to allow power of an AC power source 33 to be supplied to the compressor 5 and the blower 8. Meanwhile, a damper relay 34 is connected to the damper relay driving circuit 17, and when the damper relay 34 is energized, a contact 34a thereof is closed to allow power ofthe AC power source 33to be supplied to the damper 21.

Now, operation ofthe embodiment described above will be described with reference to flowcharts of Figures Sto 8which illustrate a program stored in the memory 26B ofthe microcomputer 26. Referring first to Figure 5 showing an entire general flow of steps of operation of the controlling device, the program includes a step 100 which is executed only after the powersource33 has been turned on, and atthis step 100, the microcomputer 26 is initialized. Following steps 200 to 600 form a main loop which is usually passed by during operation ofthe controlling device.At step 200, digital inputs such as an input from the quick refrigeration switch 2 are taken in, and at step 300, analog inputs such as inputs from the refrigerating chamber temperature detector 14, the external airtemperature detector 13 and thevariable resistor 28 are taken into the microcomputer 19.

Then,atstep400,theinputsarejudged in accord- ancewithsuch input data, and atstep 500, an output to the damper 21 is determined. Afterthen, atstep 600, various timer processings are effected, and after such processings, the process returns to step 200.

Reference is now made to Figure 6 which shows details of the temperature input taking in operation 300 of the flowchart of Figure 5. In the temperature input taking in operation 300, at first a voltage applied to the refrigerating chamber temperature detector 14 is read in and date ofthevoltagevalueconver- ted into the temperature is taken into a refrigerating chambertemperature registerTa at step 301. Then at step 302, similarly a voltage applied to the variable resistor 18 is converted into a presettemperature and data of the presettemperature is taken into a preset temperature registerTs. At step 303, an external air temperature is similarly taken into an airtemperature registerTg.Where an influence of the temperature of the external air is negligible, the step 303 can be omitted.

Now, description will be given of processings when the quick refrigeration switch 12 is depressed with reference to Figure 7 which shows details ofthe input judging operation 400 of Figure 5. In the input judging operation 400, it is judged at step 401 whether or not the quick refrigerating switch 12 is depressed, and when it is found that the switch 12 is depressed, a twice reading preventing flag Fl is judged at step 402. In case Fl is0 (in case of first reading), the flag Fl is setto "1 at step 403. Thus, since theflag F1 is thereafter judged as "1 ", processings following the step 403 are bypassed, that is, second reading is prevented.Then at step 404, a quick refrigeration flag F2 misjudged, and when the flag F2 is "1", it is judged that the quick refrigeration switch 12 has been depressed again during quick refrigerating operation so that at step 405, the quick refrigeration flag F2 is setto "O" to stop the quick refrigeration and the display lamp 18 (represented as LED in the drawing, which will apply also in the following description) 18 is ex- tinguished at step 406. On the contrary when the flag F2 is judged as "0", the quick refrigeration flag F2 is setto "1 " to start quick refrigeration at step 407 and the display lamp 18 is lit at step 408.

Subsequently, the electric damper outputting operation 500 of Figure 5 will be described in detail with reference to Figure 8. In the electric dam per out- putting operation 500, it is judged at step 501 whether the refrigerator is in a quick refrigeration mode, and when it is found that the refrigerator is in the quick refrigeration mode (F2="1 "), it is judged at step 503 whether or not the external airtemperature is lowerthan 10 C. When the external airtemperature is lowerthan 100C, a presettemperatureTs is set, at step 504, to a value lower by 1.5 degreesthanthe preset temperature Ts, but on the contrary when the external airtemperature is higherthan 10 C,the presettemperature Ts is set, at step 505, to a value lower by 3.0 degrees than the presettemperature Ts.

where an influence ofthe external airtemperature is negligible,the step 503 and eitherthe step 504 or 505 can be omitted. Subsequently at step 506, it is judged whetherthe electric damper 21 is in an open condition or in a closed condition at preset, and in case of an open condition oftheelectricdamper21, at step 507,the temperature Ta within the refrigerating chamber3 is substracted from the p reset tem- perature Ts and it is judged whether or notthe differ enceisgreaterthan 1 degree.

If the difference is greaterthan 1 degree, that at step 509, it is judged whether the refigerator is during quick refrigeration, and when it is found that therefrigerator is during quick refrigeration, a counter is incremented by one at step 510. Then, it is judged at step 511 whetherthevalue ofthe counter Cl is equal to 3, and when the value ofthe counter Cl is 3, F2 is set at O to step 512 to stop the quick refrigeration and the display lamp 18 is extinguished at step 513. On the contrary, when it is judged at step 506 thatthe damper 21 is in a closed condition at present, at step 514, the presettemperature Ts is subtracted from the refrigerating chambertemperature Ta and it is jud ged whether the difference is greaterthan 1 degree or not. When the difference is greater than 1 degree, an outputforopening the damper 21 is developed at step 515.

In this manner, quick refrigerating operation ofthe refrigerator is performed compulsorily in response to operation of the quick refrigeration switch 12, and then afterthe inside of the refrigerator has been cooled sufficiently, the quick refrigerating operation is automatically cancelled. In this instance, because the operation switch 12 is located on affront face of the opening and closing door 24, it can be readily operated, and besides since the operation of the switch 16 is displayed, it is very useful for a user.

Further, in case the quick refrigeration switch 12 is depressed to put the refrigerator into the quick refrigeration mode, the presettemperature is re-setto a lower level with a small width (1.5 deg rees in the embodiment) when the external airtemperature is lower than 10sC and with a greater width (3 degrees in the embodiment) when the external airtemperature is higher than 1 00C. Thus, the damper 21 is controlled with fixed differentials ( + 1 degrees in the embodiment). When the damper 21 is closed three times, the quick refrigeration mode is automatically cancelled. Accordingly, even if the external airtemperature is low, over cooling can be prevented when quick refrigeration is performed.

It into be notedthatwhile stopping of quick refrigeration is determined, in the embodiment described above, by counting the number of opening and closing motions ofthe damper 21 and the presettemperature can be varied relative to a change of the external airtemperature, similar actions can be attained if a timer for measuring a time of quick refrigeration is alternatively provided so that when the measuring time bythetimer reaches a preset time, the quick refrigeration is ended and the preset time of thetimer is varied in response to the external airtemperature.

Further,similareffectscan be attained if the system using timer is employed together with the system usingthe numberofopening and closing motions of the damper 11 described above.

Claims

1. A controlling device for a refrigerator of the type wherein a damper is opened or closed to control theamountofsupplyofcooling airto regulatethe temperature within said refrigerator, comprising: a quick refrigeration switch; and controlling means operable in response to operation of said quick refrigeration switch for compulsorily lowering a preset temperature within said refrigerator to perform quick refrigerating operation of said refrigerator.

2. A controlling device for a refrigerator according to claim 1, further comprising means for displaying quick refrigerating operation of said refrigerator during such operation under control of said controlling means.

3. A controlling device for a refrigerator according to claim 1, wherein said controlling means inciudes means for detecting that the number of opening and closing motions of said damper reaches a predetermined number during quick refrigerating operation of said refrigerator, said controlling means being operable to stop the quick refrigerating operation of said refrigerator in response to a detection signal from said detecting means.

4. A controlling device for a refrigerator according to claim 1, wherein said controlling means includes means for detecting that quick refrigerating operation of said refrigerator has continued for a predetermined period of time, said controlling means being operable to stop the quick refrigerating operation of said refrigerator in response to a detection signal from said detecting means.

5. A controlling device for a refrigeratoraccording to claim 1 further comprising means located near said damper for detecting a temperature within a refrigerating chamber of said refrigerator.

6. A controlling device for a refrigerator according to claim 1, wherein said quick refrigeration switch is located on an operation panel mounted on a front face of a door for a freezing chamber of said refrigerator.

7. A controlling device for a refrigeratoraccording to claim 6, further comprising means for displaying quick refrigerating operation of said refrigerator during such operation under control of said controlling means, said display means being located on said operation panel.

8. A controlling device for a refrigerator of the type wherein cooling air cooled by a cooler is blasted into a refrigerating chamber by a blower and a damper is opened and closed to regulate the amount of air blasted into said refrigerating chamber in responseto atemperaturewithin said refrigerating chamber to control the temperature within said refrigerating chamber to a preset temperature, comprising: a quick refrigeration switch; an external air temperature detector for detecting a temperature of the external air; a preset temperature lowering means operable in response to operation of said quick refrigeration switch for lowering the preset temperature for said refrigerating chamber in response to an output of said external airtemperature detector; means for detecting eitherthat the number of opening and closing motions of said damper reaches a predetermined value or that the time ofthe quick refrigerating operation reaches a predetermined time during quick refrigerating operation of said refrigerator started in response to lowering of the presettemperature; and a quick refrigeration stopping means operable in response to a detection signal from said detecting meansfordeveloping an instruction to stop the quick refrigerating operation ofsaid refrigerator.

9. A controlling device for a refrigeratoraccording to claim 8, further comprising means for displaying quick refrigerating operation of said refrigerator during such operation.