JP3313157B2 - Thaw control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerator with a thawing room for thawing frozen food.

[0002]

2. Description of the Related Art Heretofore, there has been known an example in which a heater is used for thawing frozen food. For example,
FIG. 8 is an example shown in FIG.
This will be described with reference to FIG. Reference numeral 1 denotes a thawing box, which comprises an outer box 2 formed of metal or synthetic resin, and an inner box 3 made of metal such as aluminum having a high thermal conductivity and provided inside the outer box 2 at appropriate intervals. Is formed. Numeral 4 is a linear heater, which is thermally conductively adhered to the inner box 3 by aluminum foil 5 so that the bottom surface of the thawing box 1 is sparse and the upper surface is dense. 6 is the outer box 2 and aluminum foil 5
It is a heat insulator interposed between them.

In such a configuration, when the food 7 to be thawed is placed on the bottom surface of the thawing box and the thawing action is started, the heater 4
The heat is applied from the entire circumference of the inner box 3 by heating, so that the food 7 to be thawed is heated and thawed.

[0004]

However, in such a configuration, heat is transmitted from the bottom portion of the thawing box to the bottom portion of the food to be thawed by heat conduction, so that the bottom portion can be thawed. And there is almost no radiant heating from the side, and the heating is performed mainly by the convection of the warmed air in the thawing box. For this reason, uneven thawing with the central part of the food to be thawed is likely to be large, and the thawing time is prolonged, and the thawing performance is affected by the weight and size of the food. There is also a problem that the finished state is not constant depending on the weight and size of the food.

An object of the present invention is to solve the above-mentioned problems, and it is an object of the present invention to be able to perform defrosting in a short time and without worry, with little defrosting unevenness.

[0006]

In order to solve the above-mentioned problems, a refrigerator according to the present invention comprises a reflector having a curved reflecting surface and a radiant heater provided below the reflector at a predetermined interval. A bottom plate disposed opposite to the reflection plate, a thawing chamber including a temperature sensor that is thermally conductively adhered to the back surface of the bottom plate, and a cooling chamber including the thawing chamber as a whole. ,
A fan forcing the cool air cooled by the cooler into the thawing chamber, a damper device provided at the inlet of the thawing chamber to adjust the flow rate of the cool air, a thawing switch for starting the thawing action, and a first switch during thawing. Measuring the time from the start of thawing until the temperature sensor rises to a predetermined temperature as a first step.
A timer, time storage means for storing the time measured by the first timer, first duty ratio setting means for setting a first duty ratio of the radiant heater, and a second duty time A second timer for setting the temperature of the temperature sensor at the end of the second stage, a second duty ratio setting unit for setting a second-stage duty ratio of the radiant heater, A memory for storing a control rule based on an empirical rule for obtaining a duty ratio of the radiant heater in a third stage; a first stage time stored in the time storage unit; and a second rule stored in the temperature storage unit. A fuzzy inference processor for performing a fuzzy logic operation to calculate a duty ratio of the radiant heater in a third stage based on the temperature at the end of the stage and the control rules retrieved from the memory; A third duty ratio setting means for setting the duty ratio of the radiation heater in the third stage, a third timer for setting a time period of the third stage, and the first, second, and third duty ratios A radiation heater control unit for controlling the radiation heater based on a signal from the setting unit ;
The stage is forcibly open, the second stage is forcibly closed, the third stage is
Forcibly open the fan and connect the fan to the damper device.
Control means for forcible operation when forcibly released and user's request
Finish setting switch to input the finish of the food to be thawed
Switch and finish setting switch input for the third stage
Based on the empirical rule for determining the duty ratio of the radiation heater
A plurality of memories for storing control rules and the setting switch.
Memory among the plurality of memories depending on the state of the switch.
And finish selection means for judging whether to make a selection .

[0007]

A reflecting plate having a curved reflecting surface; a radiation heater provided at a predetermined distance below the reflecting plate; a bottom plate disposed opposite to the reflecting plate; A thawing chamber equipped with a temperature sensor that is thermally conductively attached to the back surface of the face plate, and a cooling chamber provided with the thawing chamber in one piece,
A fan forcing the cool air cooled by the cooler into the thawing chamber, a damper device provided at the inlet of the thawing chamber to adjust the flow rate of the cool air, a thawing switch for starting the thawing action, and a first switch during thawing. Measuring the time from the start of thawing until the temperature sensor rises to a predetermined temperature as a first step.
A timer, time storage means for storing the time measured by the first timer, first duty ratio setting means for setting a first duty ratio of the radiant heater, and a second duty time A second timer for setting the temperature of the temperature sensor at the end of the second stage, a second duty ratio setting unit for setting a second-stage duty ratio of the radiant heater, A second memory for storing a control rule based on an empirical rule for obtaining a third stage time, a first stage time stored in the time storage unit, and a second stage end stored in the temperature storage unit A fuzzy inference processor for performing a fuzzy logic operation to calculate a third stage time based on the temperature at the time and the control rule retrieved from the memory; and a third fuzzy inference processor calculated by the fuzzy inference processor.
A third timer for setting a stage time, a third duty ratio setting means for setting a duty ratio of the radiation heater in a third stage,
A radiant heater control means for controlling the radiant heater based on signals from the first, second and third duty ratio setting means; a first stage forcibly opening the damper device;
The third step is to forcefully open and
Control for forcibly operating the damper device when the damper device is forcibly opened.
Enter the means and the desired finish of the food to be thawed by the user
Finish setting switch and the finish setting switch
Calculate the duty ratio of the radiant heater in the third stage with respect to the input
To store control rules based on heuristic rules for
Memory and the state of the setting switch.
Finish selection to determine which memory to select
Selection means .

[0009]

[0010]

According to the present invention, indirect radiation is performed through the upper surface and the reflecting surface of the food to be defrosted by the above-mentioned structure, and the food to be defrosted absorbs heat almost uniformly.

During the thawing, the fan is forcibly operated.
As a first stage, the radiation heater is energized at the duty ratio set by the first duty ratio setting means for a period of time from the start of thawing until the temperature sensor rises to a predetermined temperature, and the damper device is opened to cool the air. be introduced. As a second stage, the radiant heater is energized for a predetermined time at the energization rate set by the second energization rate setting means, and the damper device is closed to suppress the inflow of cool air.

A fuzzy logic operation is performed by a fuzzy inference processor based on the time required for the first stage, the temperature at the end of the second stage, and the control rules fetched from the memory, and a third duty ratio And a third timer time. Therefore, the optimum duty ratio and timer time are determined according to the size and weight of the food to be thawed and the user's preference based on the duty ratio and the timer time obtained as described above. Can be done.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A defrosting control device according to an embodiment of the present invention will be described below with reference to FIGS. In FIG.
8 is a refrigerator main body, an outer box 9, an inner box 10, and both boxes 9,
It is constituted by a heat insulating material 11 filled between the ten.
Reference numeral 12 denotes a cooling room (hereinafter referred to as a refrigeration room 12).
Is a freezer compartment formed above the refrigerator compartment 12. Fifteen
Is a refrigeration cycle compressor provided at the bottom of the refrigerator body 8,
Reference numeral 16 denotes a cooler provided on the back of the freezing compartment 13.

Reference numeral 17 denotes a fan for forcibly blowing the cool air cooled by the cooler 16 into the refrigerating compartment 12, freezing compartment 13, and thawing compartment 14, and 18 is provided at the inlet of the thawing compartment 14 to allow the cool air to flow by an electric input. This is a damper device that opens and closes to adjust the amount.

Numeral 21 designates a cooling air from the fan 17 to the thawing chamber 14.
Is a suction duct for returning the cool air that has cooled the inside of the thawing chamber 14 to the cooler 16.

Reference numeral 23 denotes a freezing room temperature sensor for detecting the temperature of the freezing room 13, and 24 denotes a thawing room temperature sensor.

Next, the detailed configuration of the thawing chamber 14 will be described with reference to FIG.
This will be described with reference to FIG. 25 is an outer box made of synthetic resin, 26
Is an inner box made of metal such as aluminum, and has a curved reflecting plate 27 and a bottom plate 2 which is disposed below and below the reflecting plate 27.
8 and both side plates 27 and 28 are formed by a substantially U-shaped side plate 29 connected on three sides. In addition, the thawing room temperature sensor 24
Are in close contact with the bottom plate 28 in the vicinity of the center of the back surface in a thermally conductive manner. Reference numeral 30 denotes a door provided at the front opening of the inner box 26 so as to be openable and closable, and has a double structure made of a synthetic resin in which an air layer is formed to enhance heat insulation. Reference numeral 31 denotes a quartz glass tube radiation heater provided at a predetermined interval facing the reflection plate 27 of the inner box 26, and radiates far infrared rays of about 5 μm or more. May be baked and painted to further enhance the radiation efficiency of far infrared rays.

Reference numeral 33 denotes a thawing plate which is detachably mounted on the bottom plate 28 and on which a food 34 to be thawed is placed. Reference numeral 35 denotes a protective net for preventing burns, which is attached so as to cover the radiation heater 31 at regular intervals. Reference numeral 37 denotes a heat insulating material inserted between the outer box 25 and the inner box 26, and a discharge air passage 38 communicating with the discharge duct 21 and the damper device 18 at an upper portion, and a suction air passage 39 communicating with the suction duct 22 at a rear portion. Has formed. 4
Reference numeral 0 denotes a large number of discharge ports formed in the reflection plate 27 of the inner box 26 so as to communicate the inside of the thawing chamber 14 with the discharge air path 38. This is a suction port formed in the side plate 29.

In FIG. 5, reference numeral 42 denotes a refrigerator main body 8.
An operation plate provided on a part of the outer shell of the product, which is in a user's favorite finish state (for example, "hard", "standard", "soft")
And a decompression switch 44 for starting or stopping the decompression operation.

Next, the control relationship will be described with reference to FIG. Reference numeral 50 denotes a defrosting control means, a stage control means 51,
Timer 52, second timer 53, third timer 54,
First duty ratio setting means 55, second duty ratio setting means 5
6, third energization rate setting means 57, time storage means 58, temperature storage means 59, fuzzy inference processor 60, first memory 61, second memory 62, third memory 63, finish selection means 64, heater It comprises a control means 65 and a damper control means 66.

Reference numeral 67 denotes a thawing room temperature detecting means for converting the temperature of the thawing room temperature sensor 24 to an electric signal, and 68 a freezing room temperature detecting means for converting the temperature of the freezing room temperature sensor 23 to an electric signal.

A refrigerator control means 69 controls the compressor 15 based on a signal from the freezing room temperature detecting means 68, and a fan 17 based on a signal from the freezing room temperature detecting means 68 and the thawing control means 50.
Control. This means that if the temperature of the freezer rises, the compressor 1
5 and the fan 17 are operated.
And the fan 17 is stopped, but when the thawing is started, the fan 17 is controlled to be forcibly operated.

The stage control means 51 determines whether or not the defrost switch has been depressed. If depressed, the defrost control is started, and the first timer 52 and the first energization rate setting means 55 and the second Timer 53 and second duty ratio setting means 5
6. Send an operation signal to the third timer 54 and the first duty ratio setting means 57. Further, the stage control means 51 informs the refrigerator control means 69 that the thawing has started, and informs the damper control means 66 of each stage, and the damper control means 6
6 controls the damper device 18.

The first timer 52 regulates the time of the first stage, operates by the operation signal of the stage control means 51, and continues the timer operation until the thawing room temperature detecting means 67 reaches the set temperature. The first duty ratio setting means 55 sets the duty ratio of the radiation heater 31 in the first stage.

The second timer 53 regulates the time of the second stage. The operating time is set in advance, and the second duty ratio setting means 56 sets the duty ratio of the radiant heater 31 in the second stage. Have been.

The third timer 54 regulates the time of the third stage, and the operation time is set in advance. The third duty ratio setting means 57 defines the duty ratio of the radiation heater 31 in the third stage. The duty ratio is determined by a time storage unit 58 for storing the time of the first stage, and when the second stage is completed. And a first memory 61 for storing a control rule based on an empirical rule for obtaining an energization rate corresponding to a user's favorite finishing state set by the finishing switch 43. , The second memory 62 and the third memory 63 are set by the fuzzy inference processor 60 based on the result of the fuzzy logic operation based on the control rule extracted from the memory selected by the finish selecting means 64.

The heater control means 65 controls the radiant heater 31 with the duty ratio set in the operating duty ratio setting means 55, 56, 57. At this time, the duty ratio is on / off
Not only control but also power conversion of the heater such as phase control may be performed.

The operation of such a configuration will be described with reference to the flowchart shown in FIG.

First, the food to be thawed (for example, beef steak meat having a thickness of 20 mm) 34 is placed almost at the center of the thawing dish 33 and placed on the bottom plate 26. Then, first in STEP1, the defrosting switch 44 is turned on to start defrosting control. When the thawing control is started, the stage control means 51 outputs an operation signal of the first timer 52 for measuring the time of the first stage and the first duty ratio setting means 55 in STEP2. Then, the first timer 52
Starts the time counting, and the heater control means 65 sets the radiation heater 3 at the duty ratio set by the first duty ratio setting means 55.
Control 1 In this embodiment, the duty ratio is set to 100%, and the radiation heater 31 is continuously energized.

Next, in STEP3, the stage control means 51
Sends a signal indicating that thawing has started to the refrigerator control means 69 as a thawing signal, and the refrigerator control means 69 forcibly operates the fan 17. Then, in STEP 4, the damper device 18 is forcibly opened. For this reason, 5 μm
Since the above far infrared rays are continuously and directly or indirectly radiated almost indirectly to the food 34 to be thawed via the reflection plate 25, in general foods having an absorption wavelength band in the far infrared wavelength range. Far infrared rays are efficiently absorbed, and heat quickly penetrates relatively into the food 34 to be thawed. By such continuous heating, the temperature of the food 34 to be thawed, which has been frozen (for example, −20 ° C.) in the first stage, can be quickly increased.

On the other hand, the cool air cooled by the cooler 16 is guided to the discharge air passage 38 in the thawing chamber 14 through the discharge duct 21 and the damper device 18 in the refrigerator main body by the forced air blowing action of the fan 17, and The air is blown down in a shower form from a large number of discharge ports 40 on the surface. For this reason, the radiation heater 31 described above is used.
The thawing proceeds in a state where the temperature unevenness between the surface and the center of the food 34 to be thawed does not increase while suppressing the temperature rise on the surface, in combination with the effect of the heat penetrating into the food due to the far infrared radiation. The air warmed by the heating action in the thawing chamber 14 is returned to the cooler 16 from the suction port 41 and the suction air passage 40 provided at the rear of the room via the suction duct 22 of the refrigerator body 8, and is cooled again. Repeat the circulatory action.

While such a continuous heating action with a cooling action proceeds, it is determined in STEP 5 whether the temperature of the thawing chamber temperature sensor 24 is higher or lower than a set value (for example, 15 ° C.). Wait until it becomes.

If it is determined in STEP 5 that the temperature is high (15 ° C. or higher), it is determined that the first stage has been completed, and STEP 6
The time L1 required for the first stage by proceeding to
And the first timer 52 and the first duty ratio setting means 5
Stop 5. Here, the required time L1 is substantially proportional to the area of the food.

Next, proceeding to STEP 7, the stage control means 51 sets the time of the second stage (for example, 5 minutes).
The operation signal of the timer 53 and the second duty ratio setting means 56 is output. Then, the second timer 53 starts counting time, and the heater control means 65 controls the radiant heater 31 at the duty ratio set by the second duty ratio setting means 56.
In this embodiment, the duty ratio is set to 0%, and the radiation heater 31 is set.
Is stopped. Then, in STEP8, the damper device 18 is forcibly closed.

Then, the process proceeds to STEP 9 where the second timer 53
Waits until the time count ends, and after that, STEP1
0 and the temperature T2 of the thawing chamber sensor 24 at the end of the second stage
Is stored in the temperature storage means 59, and the second timer 53, the second
Is stopped.

As described above, the heating action and the cool air blowing are interrupted, and the temperature of the food 34 to be thawed is easily transmitted to the temperature sensor 24 of the defrosting room, so that T2 indirectly detects the weight of the food to be thawed.

Next, the time L1 required for the first step measured in STEP 11 is input to the fuzzy inference processor 60. Next, in STEP 12, the temperature T2 of the thawing room temperature sensor 24 at the end of the second stage is determined by the fuzzy inference processor 6.
Input to 0.

Then, in STEP 13, the finish state input by the user with the finish setting switch 43 is judged by the finish selecting means 64, and in STEP 14, a memory storing control rules corresponding to the finish setting is selected. Here, the first memory 61 corresponds to the standard, the second memory 62 corresponds to the harder, and the third memory 63 corresponds to the softer. And STE
In P15, the fuzzy inference processor 60 takes out the control rules stored in the first memory 61 if it is the standard setting, and obtains the duty ratio D of the radiation heater 31 in the third stage by fuzzy inference.

Accordingly, the third duty ratio setting means 57
The duty ratio D obtained by the fuzzy inference processor 60
Is set (STEP 16). And STEP17
Then, the stage control means 51 outputs an operation signal of the third timer 54 in which the time of the third stage is set and the third duty ratio setting means 57. Then, the third duty ratio setting means 57 sets the ST
The heater control means 65 controls the radiation heater 31 at the duty ratio D set in EP16. Then, in STEP 18, the damper device 18 is forcibly opened.

Subsequently, the process proceeds to STEP 19, where the third timer 5
4 waits until the time count ends, and then ends with STEP
Then, the stage control means 51 goes to the refrigerator control means 6.
The transmission of the thawing signal to 9 is stopped, and the refrigerator control means 69 releases the forced operation of the fan 17. Further, the stage control means 51 controls the damper device 18 via the damper control means 66 so as to stop the control of forcibly opening or forcibly closing the damper device 18 and maintain the thawing chamber 14 at a constant temperature, for example, −3 ° C. Then, the thawing is ended in STEP21.

Here, the fuzzy inference for obtaining the optimum duty ratio D of the radiation heater 31 in the third stage is executed based on the following control rules.

The control rules employed in the first memory 61 of this embodiment are the following nine rules. For example, Rule 1: If the time of the first stage is short and the temperature of the second stage is low, set the duty ratio to a medium level.

Rule 2: If the time of the first stage is short,
If the temperature in the second stage is moderate, reduce the electric conductivity a little.

Rule 3: If the time of the first stage is short,
If the temperature in the second stage is high, reduce the duty ratio.・ ・ ・ Rule 7: If the time of the first stage is long and the temperature of the second stage is low, increase the duty ratio.

Rule 8: If the time of the first stage is long,
If the temperature in the second stage is moderate, increase the conductivity slightly.

Rule 9: If the time of the first stage is long,
If the temperature in the second stage is high, set the duty ratio to a medium level. And so on.

This is because if the area of the food 34 to be thawed increases, the time of the first stage becomes longer, so that the longer the time of the first stage, the more difficult it is to conduct heat and the more difficult it is to thaw, and it is necessary to increase the electric conduction rate. There is. In addition, the food to be thawed 34
Is larger, the temperature of the second stage is lower, so the lower the temperature of the second stage, the larger the load and the higher the duty ratio.

Thus, the language rule is a control rule that can be set to an optimal duty ratio obtained from experimental data, and is based on the relationship between the time L in the first stage and the temperature T in the second stage. (Table 1).

[0049]

[Table 1]

Table 1 is a table showing the relationship between the control rules. In the horizontal direction, the time L of the first stage is set to three stages (BL = large, M
L = medium, SL = small), and the second stage temperature T
Are arranged in three stages (HT = high, MT = medium, LT = low), and the intersection of the first stage time L and the second stage temperature T is located at the intersection of the first stage time L and the second stage temperature T. The optimum duty ratio D corresponding to the time L of the first stage and the temperature T of the second stage is arranged.

When the language rules are stored in the first memory 61 of FIG. 1, they are stored according to the following rule. The number of control rules employed in this embodiment is nine.

Rule 1: IF Lis SL and Tis LT THEN Dis M Rule 2: IF Lis SL and Tis MT THEN Dis MS Rule 3: IF Lis SL and Tis HT THEN Dis S. Rule 7: IF Lis BL and Tis LT THEN Dis B Rule 8: IF Lis BL and Tis MT THEN Dis MB Rule 9: IF Lis BL and Tis HT THEN Dis M Control Rule 1, Since the rules of rules 2,..., And rule 9 determine the time L of the first step, the temperature T of the second step, and the duty ratio D stepwise as shown in (Table 1), fine control is performed. Is carried out, the measured first stage time L is intermediate between the first stage time L and the second stage temperature T.
1 and the temperature T2 in the second stage, the antecedent (I
Calculate the degree of satisfying F part),
It is necessary to estimate the duty ratio D at the set temperature according to the degree. Therefore, in the present embodiment, the degree is calculated using a membership function of a fuzzy variable with respect to the time L of the first stage and the temperature T of the second stage.

FIG. 7A shows the membership function μS of the fuzzy variables SL, ML and BL with respect to the time L in the first stage.
FIG. 7B shows L (L1), μML (L1), and μBL (L1). FIG. 7B shows the membership function μL of the fuzzy variables LT, MT, and HT with respect to the temperature T in the second stage.
T (T2), μMT (T2), and μHT (T2).

The fuzzy inference executed by the fuzzy inference processor 60 performs a fuzzy logic operation using control rules 1, rules 2,..., Rule 9 and the membership functions shown in FIGS. 7 (a) and 7 (b). A third stage operation rate calculation is performed.

Hereinafter, the procedure of fuzzy inference which is STEP 15 of FIG. 6 will be described with reference to the flowchart of FIG.

In STEP 30, the first stage time L1 and the second stage temperature T are set by the fuzzy inference processor 60.
Using the fuzzy variable membership function for 2
A membership value (shown as M value in the figure) at the first stage time L1 and the second stage temperature T2 is calculated.

In STEP 31, the degree to which the obtained membership values of the fuzzy variables for the first-stage time L1 and the second-stage temperature T2 satisfy the antecedents of the nine rules is as follows. It is calculated by the synthesis method as shown in FIG.

In the figure, A represents a fuzzy variable for the time L in the first stage, and B represents a fuzzy variable for the temperature T in the second stage.

Rule 1: h1 = μSL (L1) ∩μLT (T2)
= ΜSL (L1) × μLT (T2) --- (1) Rule 2: h2 = μSL (L1) ∩ μMT (T2)
= ΜSL (L1) × μMT (T2) --- (2) Rule 3: h2 = μSL (L1) ∩ μHT (T2)
= ΜSL (L1) × μHT (T2) --- (2) Rule 7: h7 = μBL (L1) ∩ μLT (T2)
= ΜBL (L1) × μLT (T2) Rule (8): h8 = μBL (L1) ∩μMT (T2)
= ΜBL (L1) × μMT (T2) --- (8) Rule 9: h9 = μBL (L1) ∩μHT (T2)
= ΜBL (L1) × μHT (T2) (9) Equation (1) indicates that L1 is the area SL with respect to the time L of the first stage.
And T2 is the region L for the temperature T of the second stage.
The proposition to enter T indicates that the ratio of L1 to SL and the ratio of T2 to LT are satisfied by the product value, that is, the antecedent of Rule 1 is satisfied by the ratio of h1. Similarly, in the case of rules 2,..., And rule 9, which are formulas (2),.
.., H9.

In STEP 32, the first-stage time L1 and the second-stage time L1 are set in accordance with the membership function of the execution unit of the control rule.
The third stage duty ratio D at the stage temperature T2 is determined as follows. The energization rate D is expressed as a value of a weighted average of the ratios h1, h2,..., H9 of the antecedents of the respective control rules using a height method which is one of the single point methods. Calculate as shown in

[0061]

(Equation 1)

As a result, the third stage duty ratio D is obtained. In addition, the control rule adopted in the second memory 62 of the present embodiment corresponds to the first rule because the finished state corresponds to the harder finish.
The control rule adopted in the first memory 61 is lower than the control rule adopted in the first memory 61 because the duty ratio is lower than the control rule adopted in the memory 61, and the control rule adopted in the third memory 63 corresponds to a softer finished state. , The energization rate is high, the second
The control rules adopted by the memory 62 are: Rule 1: If the time of the first step is short and the temperature of the second step is low, reduce the duty ratio slightly.

Rule 2: If the time of the first stage is short,
If the temperature in the second stage is moderate, reduce the duty ratio.

Rule 3: If the time of the first stage is short,
If the temperature in the second stage is high, make the conduction rate very small.・ ・ ・ Rule 7: If the time of the first stage is long and the temperature of the second stage is low, increase the duty ratio slightly.

Rule 8: If the time of the first stage is long,
If the temperature in the second stage is moderate, set the duty ratio to moderate.

Rule 9: If the time of the first stage is long,
If the temperature in the second stage is high, the duty ratio should be slightly reduced.
And so on.

The control rules adopted in the third memory 63 are: Rule 1: If the time of the first stage is short and the temperature of the second stage is low, increase the duty ratio a little.

Rule 2: If the time of the first stage is short,
If the temperature in the second stage is moderate, set the duty ratio to moderate.

Rule 3: If the time of the first stage is short,
If the temperature in the second stage is high, the duty ratio should be slightly reduced.・ ・ ・ Rule 7: If the time of the first stage is long and the temperature of the second stage is low, increase the duty ratio very much.

Rule 8: If the time of the first stage is long,
If the temperature in the second stage is moderate, increase the duty ratio.

Rule 9: If the time of the first stage is long,
If the temperature in the second stage is high, increase the duty ratio a little. And so on.

Therefore, in this embodiment, the time of the first stage and the temperature of the second stage are used as the control parameters, and the radiant heater 3 optimal for the area and size of the food 34 to be thawed is used.
Thawing can be performed at a duty ratio of 1 and fine control is possible.

Further, since the control rule for inferring the duty ratio is switched according to the setting of the finishing state, it is possible to make the finishing state that the user prefers.

Next, another embodiment will be described with reference to the drawings. In the drawings, components having the same configurations as those of the conventional example and the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted. The configuration of the refrigerator and the configuration of the thawing chamber 14 of FIGS. 2 to 5 are the same as those of the first embodiment.

In FIG. 9, reference numeral 70 denotes a decompression control means, which is a stage control means 51, a first timer 52, and a second timer 5.
3, a third timer 71, a first duty ratio setting means 55, a second duty ratio setting means 56, a third duty ratio setting means 72,
Time storage means 58, temperature storage means 59, fuzzy inference processor 80, first memory 81, second memory 82,
It comprises a third memory 83, a finish selection means 64, a heater control means 65, and a damper control means 66.

The third duty ratio setting means 72 defines the duty ratio of the radiation heater 31 in the third stage, and the duty ratio is set in advance. The third timer 71 regulates the time of the third stage. The timer time includes a time storage means 58 for storing the time of the first stage, and a temperature for storing the temperature of the thawing chamber when the second stage is completed. A first memory 71, a second memory 82 for storing a control rule based on an empirical rule for obtaining a duty ratio corresponding to a user's favorite finishing state set by the finishing switch 43;
The fuzzy inference processor 80 sets the fuzzy logic operation result based on the control rule extracted from the memory selected by the finish selecting means 64 in the third memory 83.

The operation of such a configuration will be described with reference to the flowchart shown in FIG.

First, the food 34 to be thawed is placed almost at the center of the thawing dish 33 and placed on the bottom plate 26. Then, first in STEP 1, the defrost switch 4
By turning on 4, the thawing action is started. When the thawing control starts, the stage control means 5 in STEP 2
1 outputs an operation signal of the first timer 52 for measuring the time of the first stage and the first duty ratio setting means 55. Then, the first timer 52 starts counting time, and the heater control unit 65 controls the radiant heater 31 at the duty ratio set by the first duty ratio setting unit 55. In this embodiment, the duty ratio is 10
It is set to 0%, and the radiation heater 31 is continuously energized.

Next, in STEP3, the stage control means 51
Sends a signal indicating that thawing has started to the refrigerator control means 69 as a thawing signal, and the refrigerator control means 69 forcibly operates the fan 17. Then, in STEP 4, the damper device 18 is forcibly opened. For this reason, 5 μm
Since the above far infrared rays are continuously and directly or indirectly radiated almost indirectly to the food 34 to be thawed via the reflection plate 25, in general foods having an absorption wavelength band in the far infrared wavelength range. Far infrared rays are efficiently absorbed, and heat quickly penetrates relatively into the food 34 to be thawed. By such continuous heating, the temperature of the food 34 to be thawed which has been frozen in the first stage can be quickly raised.

On the other hand, the cool air cooled by the cooler 16 is guided to the discharge air passage 38 in the thawing chamber 14 through the discharge duct 21 and the damper device 18 in the refrigerator main body by the forced air blowing action of the fan 17, The air is blown down in a shower form from a large number of discharge ports 40 on the surface. For this reason, the radiation heater 31 described above is used.
The thawing proceeds in a state where the temperature unevenness between the surface and the center of the food 34 to be thawed does not increase while suppressing the temperature rise on the surface, in combination with the effect of the heat penetrating into the food due to the far infrared radiation. The air warmed by the heating action in the thawing chamber 14 is returned to the cooler 16 from the suction port 41 and the suction air passage 40 provided at the rear of the room via the suction duct 22 of the refrigerator body 8, and is cooled again. Repeat the circulatory action.

While the continuous heating action including the cooling action proceeds, it is determined in STEP 5 whether the temperature of the thawing chamber temperature sensor 24 is higher or lower than a set value.
Wait until it becomes high at P5.

If it is determined in STEP 5 that the temperature is high, it is determined that the first stage has been completed, and the process proceeds to STEP 6 where the time L1 required for the first stage is stored in the time storage means 58, and the timer 52 and the first The duty ratio setting means 55 is stopped. Here, the required time L1 is substantially proportional to the area of the food.

Next, proceeding to STEP 7, the stage control means 51 sets a second timer 53 for setting the time of the second stage.
Then, an operation signal of the second duty ratio setting means 56 is output.
Then, the second timer 53 starts counting time, and the heater control means 65 controls the radiant heater 31 at the duty ratio set by the second duty ratio setting means 56. In this embodiment, the duty ratio is set to 0%, and the radiation heater 31 is stopped. Then, in STEP8, the damper device 18 is forcibly closed.

Then, the process proceeds to STEP 9 where the second timer 53
Waits until the time count ends, and after that, STEP1
0 and the temperature T2 of the thawing chamber sensor 24 at the end of the second stage
Is stored in the temperature storage means 59, and the second timer 53, the second
Is stopped.

As described above, the heating action and the cool air blowing are interrupted, and the temperature of the food 34 to be defrosted is easily transmitted to the temperature sensor 24 of the defrosting room, so that T2 indirectly detects the weight of the food to be defrosted.

Next, the time L1 required for the first stage measured in STEP 41 is input to the fuzzy inference processor 80. Next, in step 42, the temperature T2 of the thawing room temperature sensor 24 at the end of the second stage is determined by the fuzzy inference processor 8.
Input to 0.

Then, in STEP 13, the finish state inputted by the user with the finish setting switch 43 is judged by the finish selecting means 64, and in STEP 14, a memory storing a control rule corresponding to the finish setting is selected. Here, the first memory 71 corresponds to the standard, the second memory 82 corresponds to the harder, and the third memory 83 corresponds to the softer. And STE
In P43, the fuzzy inference processor 80 takes out the control rules stored in the first memory 71 if it is the standard setting, and obtains the third stage timer time TM by fuzzy inference.

Thus, the third timer 71 is set to the timer time TM obtained by the fuzzy inference processor 80 (STEP 44). Then, in STEP 17, the stage control means 51 sets the third stage time to the third
The operation signal of the timer 71 and the third duty ratio setting means 72 is output. Then, the third power supply rate setting means 72 controls the radiant heater 31 with the heater control means 65 at the set power supply rate. Then, in STEP 18, the damper device 18 is forcibly opened.

Subsequently, the flow proceeds to STEP 19, where the third timer 7
1 counts the time, waits until the time set in STEP 44 is reached, and proceeds to STEP 20 after completion. The stage control means 51 stops sending the thawing signal to the refrigerator control means 69, and the refrigerator control means 69 To cancel the forced operation. Further, the stage control means 51 stops the control of forcibly opening or forcibly closing the damper device 18 and the thawing chamber 1
The damper device 18 is controlled via the damper control means 66 so as to maintain the temperature at a constant temperature, for example, −3 ° C. And S
The thawing is ended in TEP21.

Here, the fuzzy inference for obtaining the timer time TM in the third stage is executed based on the following control rules.

The control rules adopted in the first memory 71 of the present embodiment are the following nine rules. For example, Rule 1: If the time of the first stage is short and the temperature of the second stage is low, set the timer time to a medium value.

Rule 2: If the time of the first stage is short,
If the temperature in the second stage is moderate, shorten the timer time slightly.

Rule 3: If the time of the first stage is short,
If the temperature in the second stage is high, shorten the timer time. Rule 7: If the time of the first step is long and the temperature of the second step is low, increase the timer time.

Rule 8: If the time of the first stage is long,
If the temperature in the second stage is moderate, increase the timer time slightly.

Rule 9: If the time of the first stage is long,
If the temperature in the second stage is high, set the timer time to a medium value.
And so on.

The reason is that, if the area of the food 34 to be thawed increases, the time of the first stage becomes longer. Therefore, as the time of the first stage becomes longer, the heat is hardly transmitted and the thawing becomes difficult.
It is necessary to increase the timer time of the stage. Also, if the size of the food 34 to be thawed increases, the temperature in the second stage decreases, so that the lower the temperature in the second stage, the greater the load and the longer the timer time in the third stage. It is a rule obtained from such experience.

Therefore, the language rule is a control rule that can set an optimal timer time obtained from the experimental data, and is based on the relationship between the time L in the first stage and the temperature T in the second stage. (Table 2).

[0098]

[Table 2]

(Table 2) is a table showing the relationship between the control rules, and the time L of the first stage is set to three stages (BL = large, M
L = medium, SL = small), and the second stage temperature T
Are arranged in three stages (HT = high, MT = medium, LT = low), and the intersection of the first stage time L and the second stage temperature T is located at the intersection of the first stage time L and the second stage temperature T. Optimal timer time T corresponding to one stage time L and second stage temperature T
M is arranged.

When the language rules are stored in the first memory 71 of FIG. 1, they are stored according to the following rule. The number of control rules employed in this embodiment is nine.

Rule 1: IF Lis SL and Tis LT THEN TM is M Rule 2: IF Lis SL and Tis MT THEN TM is MS Rule 3: IF Lis SL and Tis HT THEM TM Rule 7: IF Lis BL and Tis LT THEN TM is L Rule 8: IF Lis BL and Tis MT THEN TM is ML Rule 9: IF Lis BL and Tis HT THEN TM is M Control Rule 1, The rules of rules 2,..., And rule 9 determine the time L of the first step, the temperature T of the second step, and the timer time TM stepwise as shown in (Table 2). Is performed, the time L of the first stage and the second time
In the first stage time L1 and the second stage temperature T2 of the actual measurement in the middle of each stage of the stage temperature T, the degree to which the antecedent (IF) of the control rule is satisfied is calculated. It is necessary to estimate the timer time TM of the set temperature according to the degree. Therefore, in the present embodiment, the degree is calculated using a membership function of a fuzzy variable with respect to the time L of the first stage and the temperature T of the second stage.

FIG. 11A shows the membership function μ of the fuzzy variables SL, ML and BL with respect to the time L in the first stage.
FIG. 11B shows SL (L1), μML (L1), and μBL (L1). FIG. 11B shows the membership function μLT (T2) of the fuzzy variables LT, MT, and HT with respect to the temperature T in the second stage. , ΜMT (T2) and μHT (T2).

The fuzzy inference executed by the fuzzy inference processor 80 performs a fuzzy logic operation using control rules 1, rules 2,..., Rule 9 and the membership functions of FIGS. 11 (a) and 11 (b). The third stage timer time is calculated.

Hereinafter, the procedure of fuzzy inference, STEP 43 of FIG. 10, will be described with reference to the flowchart of FIG.

At STEP 30, the first stage time L1 and the second stage temperature T are set by the fuzzy inference processor 80.
Using the fuzzy variable membership function for 2
A membership value (shown as M value in the figure) at the first stage time L1 and the second stage temperature T2 is calculated.

In STEP 31, the degree to which the obtained membership values of the fuzzy variables for the first-stage time L1 and the second-stage temperature T2 satisfy the antecedents of the nine rules is as follows. It is calculated by the synthesis method as shown in FIG.

In the figure, the fuzzy variable for the first stage time L is indicated by A, and the fuzzy variable for the second stage temperature T is indicated by B.

Rule 1: h1 = μSL (L1) ∩μLT (T2)
= ΜSL (L1) × μLT (T2) --- (1) Rule 2: h2 = μSL (L1) ∩ μMT (T2)
= ΜSL (L1) × μMT (T2) --- (2) Rule 3: h2 = μSL (L1) ∩ μHT (T2)
= ΜSL (L1) × μHT (T2) --- (2) Rule 7: h7 = μBL (L1) ∩ μLT (T2)
= ΜBL (L1) × μLT (T2) Rule (8): h8 = μBL (L1) ∩μMT (T2)
= ΜBL (L1) × μMT (T2) --- (8) Rule 9: h9 = μBL (L1) ∩μHT (T2)
= ΜBL (L1) × μHT (T2) (9) Equation (1) indicates that L1 is the area SL with respect to the time L of the first stage.
And T2 is the region L for the temperature T of the second stage.
The proposition to enter T indicates that the ratio of L1 to SL and the ratio of T2 to LT are satisfied by the product value, that is, the antecedent of Rule 1 is satisfied by the ratio of h1. Similarly, in the case of rules 2,..., And rule 9, which are formulas (2),.
.., H9.

In STEP 32, the first-stage time L1 and the second-stage time L1 are set by the membership function of the execution unit of the control rule.
The third stage timer time TM at the stage temperature T2 is determined as follows. The timer time TM is calculated as a weighted average value of the ratios h1, h2,..., H9 of the antecedents of the respective control rules using a height method, which is one of the single point methods. Calculate as shown in

[0110]

(Equation 2)

As a result, the third-stage timer time TM is obtained. Further, since the control rule adopted in the second memory 82 of the present embodiment corresponds to a harder finished state,
Since the timer time is shorter than the control rule adopted in the first memory 71, and the control rule adopted in the third memory 83 corresponds to a softer finished state, the control rule adopted in the first memory 71 is used. The timer time is set higher than the rule, and the control rule adopted in the second memory 82 is Rule 1: If the time of the first stage is short and the temperature of the second stage is low, shorten the timer time slightly.

Rule 2: If the time of the first stage is short,
If the temperature in the second stage is moderate, shorten the timer time.

Rule 3: If the time of the first stage is short,
If the temperature in the second stage is high, make the timer time very short. Rule 7: If the time of the first step is long and the temperature of the second step is low, make the timer time slightly longer.

Rule 8: If the time of the first stage is long,
If the temperature in the second stage is medium, set the timer time to medium.

Rule 9: If the time of the first stage is long,
If the temperature in the second stage is high, shorten the timer time slightly. And so on.

The control rules adopted in the third memory 83 are as follows: Rule 1: If the time of the first stage is short and the temperature of the second stage is low, increase the timer time slightly.

Rule 2: If the time of the first stage is short,
If the temperature in the second stage is medium, set the timer time to medium.

Rule 3: If the time of the first stage is short,
If the temperature in the second stage is high, shorten the timer time slightly. Rule 7: If the time of the first step is long and the temperature of the second step is low, make the timer time very long.

Rule 8: If the time of the first stage is long,
If the temperature in the second stage is moderate, increase the timer time.

Rule 9: If the time of the first stage is long,
If the temperature in the second stage is high, increase the timer time slightly. And so on.

Therefore, in this embodiment, the time of the first stage and the temperature of the second stage are used as the control parameters, and the optimum time of the third stage is inferred from the area and the size of the food 34 to be thawed. And fine control is possible.

Further, since the control rule for inferring the timer time is switched according to the setting of the finishing state, the finishing state that the user prefers can be achieved.

[0123]

As described above, the present invention provides a curved reflecting surface.
And a predetermined interval below the reflector.
And a radiant heater provided at a position opposite to the reflection plate.
The bottom plate and the back of the bottom plate are brought into close contact with heat conduction.
A thawing room equipped with a temperature sensor, and the thawing room
A cooling chamber provided with the cooling air,
And a fan for forced ventilation at the entrance of the thawing chamber
Start the thawing action with a damper device to adjust the cold air inflow.
Thawing switch to thawing and thawing and opening as the first stage during thawing
From the beginning until the temperature sensor rises to a predetermined temperature
A first timer for measuring the time interval, and measuring with the first timer
Time storage means for storing the time taken, and the radiation heater
First duty ratio setting means for setting the first stage duty ratio
A second timer for setting the time of the second stage;
Temperature storage for storing the temperature of the temperature sensor at the end of the step
Means and setting a second stage duty ratio of the radiant heater
A second energization rate setting means;
Memorizes control rules based on empirical rules for determining the duty ratio
And a first stage stored in the time storage means
Time and the end of the second stage stored in the temperature storage means
Temperature and the control rules retrieved from the memory.
To perform a fuzzy logic operation, and
A fuzzy inference processor for calculating the heater duty ratio;
Third stage calculated by the fuzzy inference processor
A third duty ratio setting for setting the duty ratio of the radiation heater
Means, a third timer for setting a third stage time,
On the basis of signals from the first, second and third duty ratio setting means,
Radiation heater control means for controlling the radiation heater;
Forcibly open the damper device in the first stage, forcibly in the second stage
The third stage is forcibly opened and the fan is closed.
For forcibly operating the damper device when the damper device is forcibly opened.
Enter the column and the desired finish of the food to be thawed.
The finish setting switch and the finish setting switch.
The third stage determines the duty ratio of the radiant heater with respect to the force.
Memos that store control rules based on heuristic rules
And the plurality of memories depending on the state of the setting switch.
Finish selection to determine which memory to select
With this configuration of the first and second means , the first stage time and the second stage
The temperature of the stage is memorized, and thawing can be performed at the optimal duty ratio of the radiation heater according to the area and size of the food to be thawed,
Fine control is possible.

Further, since the control rule for inferring the duty ratio is switched by setting the finishing state, the finishing state that the user prefers can be achieved.

Further, a reflecting plate having a curved reflecting surface is formed.
And radiation provided at a predetermined interval below the reflection plate.
A heater, a bottom plate disposed opposite to the reflection plate,
A temperature sensor that is thermally conductively attached to the back of the bottom plate
A thawing chamber provided, and a cooling chamber provided with the thawing chamber in one piece,
Forcing the cool air cooled by the cooler into the thawing chamber
Fan and at the entrance of the thawing room to control the cool air inflow
Damper device and defrost switch to start defrosting action
During the thawing as the first stage,
The first to measure the time it takes for the sensor to rise to a predetermined temperature
And the time measured by the first timer are stored.
Time storage means for performing the first stage energization of the radiation heater
First energization rate setting means for setting the rate, and in the second stage
A second timer for setting the time interval and the temperature at the end of the second phase.
Temperature storage means for storing the temperature of the temperature sensor;
Second duty ratio setting procedure for setting the duty ratio of the second stage of data
Dan and empirical rules for determining the time of the third stage
A second memory for storing control rules, and the time storage means
Stored in the temperature storage means and the first stage time stored in the
And the temperature at the end of the second stage
Fuzzy logic operation is performed based on the set control rules.
Fuzzy inference processor that calculates the time of the third stage
And a third calculated by the fuzzy inference processor.
A third timer for setting the time of the stage and the release of the third stage
A third duty ratio setting means for setting the duty ratio of the firing heater;
Based on the signals of the first, second and third duty ratio setting means,
Radiation heater control means for controlling the radiation heater;
The damper device is forcibly opened in the first stage and hard in the second stage.
The third step is to forcefully open and
Control for forcibly operating the damper device when the damper device is forcibly opened.
Enter the means and the desired finish of the food to be thawed by the user
Finish setting switch and the finish setting switch
Calculate the duty ratio of the radiant heater in the third stage with respect to the input
To store control rules based on heuristic rules for
Memory and the state of the setting switch.
Finish selection to determine which memory to select
Selection means .

With this configuration, the time of the first stage and the temperature of the second stage are stored, the optimal time of the third stage can be inferred based on the area and size of the food to be thawed, and thawing can be performed. Control is possible.

Further, since the control rule for inferring the timer time is switched according to the setting of the finishing state, the finishing state that the user prefers can be achieved.

[Brief description of the drawings]

FIG. 1 is a block diagram of a defrost control device showing a first embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of a refrigerator with a thawing room provided with a thawing room of the present invention.

FIG. 3 is a perspective view of the thawing chamber of FIG. 2;

FIG. 4 is a sectional view of the thawing chamber of FIG. 2 taken along the line A-A ′.

FIG. 5 is an enlarged view of a thawing operation plate.

FIG. 6 is a flowchart of a defrosting control according to the first embodiment of the present invention.

FIG. 7A is a graph showing a membership function of a fuzzy variable with respect to time required for a first step in the first embodiment of the present invention. FIG. 7B is a graph showing a second step in the first embodiment of the present invention. Graph showing the fuzzy variable membership function against the thawing room temperature at the end of the run

FIG. 8 is a flowchart for explaining the procedure of fuzzy inference in FIG. 6;

FIG. 9 is a block diagram of a defrost control device showing a second embodiment of the present invention.

FIG. 10 is a flowchart of a defrosting control according to a second embodiment of the present invention.

FIG. 11A shows a first embodiment of the second embodiment of the present invention.
A graph showing the membership function of the fuzzy variable with respect to the time required for the step (b) is a graph showing the membership function of the fuzzy variable with respect to the time required for the first step in the second embodiment of the present invention

FIG. 12 is a perspective view of a thawing box showing a conventional example.

13 is a sectional view of the thawing box of FIG. 12 taken along the line BB.

[Explanation of symbols]

 14 Thawing Room 17 Fan 18 Damper Device 24 Thawing Room Temperature Sensor 29 Radiant Heater 31 Temperature Sensor 43 Finish Setting Switch 44 Thawing Switch 51 Stage Control Means 52 First Timer 53 Second Timer 57 Third Conductivity Setting Means 58 Temperature Storage means 59 Time storage means 60 Fuzzy inference processor 61 First memory 62 Second memory 63 Third memory 64 Finish setting selection means 65 Heater control means 66 Damper control means 69 Refrigerator control means 71 Third timer 80 Fuzzy inference Processor 81 First memory 82 Second memory 83 Third memory

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-4-240380 (JP, A) JP-A-4-187969 (JP, A) JP-A-4-28990 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) F25D 11/02 F25D 23/12

Claims (2)

(57) [Claims] A reflecting plate having a curved reflecting surface; a radiation heater provided below the reflecting plate at a predetermined interval; a bottom plate disposed opposite to the reflecting plate; A thawing chamber having a temperature sensor closely contacted with the back surface of the face plate in a thermally conductive manner, a cooling chamber provided with the thawing chamber in one piece, and a fan forcing the cool air cooled by the cooler to the thawing chamber. A damper device provided at the inlet of the thawing chamber to adjust the amount of inflow of cold air, a thawing switch to start a thawing operation, and the temperature sensor rises to a predetermined temperature from the start of thawing as a first stage during thawing. A first timer for measuring the time until the first timer, time storage means for storing the time measured by the first timer, and first duty ratio setting means for setting a first-stage duty ratio of the radiant heater. And a second timer for setting the time of the second stage Temperature storage means for storing the temperature of the temperature sensor at the end of the second step, second power rate setting means for setting a second step power rate of the radiation heater,
A memory for storing a control rule based on an empirical rule for obtaining a duty ratio of the radiant heater in a third stage; a first stage time stored in the time storage unit; and a second rule stored in the temperature storage unit. A fuzzy inference processor for performing a fuzzy logic operation to calculate the duty ratio of the radiant heater in a third stage based on the temperature at the end of the stage and the control rules retrieved from the memory; A third duty ratio setting means for setting a duty ratio of the radiant heater in a third stage, a third timer for setting a time in a third stage, and the first, second and third duty ratio setting devices; a radiant heater control means for controlling the radiant heater based on a signal, the first stage the damper device
Forced opening, second stage forced closing, third stage forced opening
Release the fan and forcibly open the damper device.
Control means for forcible operation when
Finish setting switch to input the finish of the defrosted food
Before the third stage for the input of the finish setting switch
An Empirical Rule for Finding the Duty Rate of a Radiant Heater
A plurality of memories for storing control rules, and the setting switch
Which memory is selected from the plurality of memories according to the state of
A defrosting control device comprising a finish selecting means for determining whether to perform the defrosting. A reflector having a curved reflecting surface;
Radiant heater provided at a predetermined interval below the reflection plate
A bottom plate disposed opposite to the reflection plate; and the bottom surface
A temperature sensor that is in thermal contact with the back of the plate
A thawing chamber, a cooling chamber provided with the thawing chamber in one piece, and a cooler
Fan for forcing the cool air cooled in
And a damper which is provided at the entrance of the thawing chamber and controls the amount of cold air inflow.
Thawing device, a thawing switch to start the thawing action, and a solution
During the freezing, the temperature sensor is
A first tie that measures the time to rise to a predetermined temperature
To store the time measured by the first timer
Storage means and a first-stage duty ratio of the radiation heater.
A first duty ratio setting means for setting the time and a time for the second stage.
A second timer to determine the temperature sensor at the end of the second phase.
Temperature storage means for storing the temperature of the heater;
Second duty ratio setting means for setting a second stage duty ratio;
A rule of thumb based on an empirical rule for determining time
A second memory for storing the time information, and a memory for storing the time in the time storage means.
The time of the first stage and the temperature stored in the temperature storage means.
The temperature at the end of the second stage and the temperature removed from the memory
Fuzzy logic operation is performed based on the control rule.
A fuzzy inference processor for calculating the time of the step;
At the third stage calculated by the fuzzy inference processor
A third timer for setting the interval and the radiant heater in a third stage
Third duty ratio setting means for setting the duty ratio of the
The first, second and third duty ratio setting means based on the signal
Radiant heater control means for controlling a radiant heater;
The first stage is forcibly opened, and the second stage is forcibly closed.
In the third stage, the fan is forced open and the fan
Control means for forcibly operating when the damper device is forcibly opened
And the desired finish of the food to be thawed by the user
Finish setting switch and input of finish setting switch
Based on empirical rules for finding the third stage time for
A plurality of memories for storing control rules, and the setting switch;
Which memory is selected from among the plurality of memories according to the state of the switch.
Decompression system consisting of finish selection means to determine whether to select
Control device.