JPH06101951A - Refrigerator - Google Patents

Abstract

PURPOSE:To perform a refrigerating and storing with less deterioration in the quality in a refrigerator having a fast refrigerating chamber for use in rapidly refrigerating a food irrespective of an environmental condition, a temperature of food or its size. CONSTITUTION:An inlet port of a fast refrigerating chamber is provided with a damper unit. A compressor 9 and a blower 11 and started to perform a forced operation in concurrent with a starting of fast refrigerating operation. The damper unit 30 is at first controlled to be opened or closed with a second temperature sensing means 45 arranged at one corner within the fast refrigerating chamber so as to stabilize a food substantially at about -1 deg.C just before a maximum ice crystal producing region and to perform a uniform temperature processing. Subsequently, there is provided a control means 38 for forcedly releasing the damper unit 30, continuously refrigerating sufficient cooled cold air to perform a refrigerating operation and automatically finishing the operation in response to the outputs of the first and second temperature sensing means 44 and 45.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a forced ventilation type refrigerator provided with a quick freezing compartment in a freezing compartment.

[0002]

2. Description of the Related Art An example of a refrigerator provided with a quick freezing compartment is shown in Japanese Utility Model Laid-Open No. 58-041464, and its construction will be described below with reference to FIGS.

A refrigerator body 1 is composed of an outer box 2, an inner box 3 and a heat insulating material 4 filled between the outer box 2 and the inner box 3. Reference numeral 5 denotes a partition wall that divides the inside of the refrigerator body 1 into upper and lower parts, and is formed by partitioning a freezer compartment 6 at an upper part and a refrigerating compartment 7 at a lower part. In addition, a low temperature chamber 8 which is set in an intermediate temperature zone between freezing and refrigeration such as partial freezing is formed in the upper part of the refrigerating chamber 7 for the purpose of storing fresh food. Reference numeral 9 is a refrigeration cycle compressor housed in the bottom rear portion of the refrigerator body 1. Reference numeral 10 is a cooler for the refrigeration cycle housed in the back surface of the freezer compartment 6, and 11 is a blower for forcedly ventilating the cool air cooled by the cooler 10 to the freezer compartment 6, the refrigerating compartment 7 and the low temperature compartment 8. is there. 12 is a duct for guiding cold air to the refrigerating chamber 7 and the low temperature chamber 8;
Reference numeral 14 denotes a damper device (hereinafter referred to as electric dampers 13 and 14) provided at the entrances of the refrigerating chamber 7 and the low temperature chamber 8 to adjust the amount of cold air inflow by electric input. 15, 16, 17
Are temperature sensors provided in the freezing room 6, the refrigerating room 7, and the low temperature room 8, respectively.

Next, 18 is a quick freezing compartment (hereinafter referred to as a quick freezing compartment 18) defined in the lower portion of the freezing compartment 6, which has a door 19 which can be opened and closed at the front and a metal plate 20 made of, for example, aluminum at the bottom. It is provided. Reference numeral 21 is a food that is placed on the metal plate 20 and is rapidly frozen. Reference numeral 22 is a cold air discharge port provided on the back surface of the room, and 23 is a cold air suction port provided on the bottom surface of the front part of the room. Reference numeral 24 denotes a quick freeze switch provided on the front surface of the outer shell of the refrigerator main body 1.
When 4 is pressed, the compressor 9 and the blower 11 are continuously operated for a predetermined time.

The operation of the above arrangement will be described below. Normally, the compressor 9 and the blower 11 are turned on / off based on the set value of the temperature sensor 15 provided in the freezer compartment 6.
F, and the cool air cooled by the cooler 10 is blower 1
1 to cool the freezing chamber 6 and the quick freezing chamber 18 so as to maintain a constant temperature (for example, −20 ° C.). On the other hand, cool air is blown by the blower 11 to the refrigerating chamber 7 and the low temperature chamber 8 through the duct 12, and the electric dampers 13 and 14
The inflow of cold air is adjusted by a constant temperature (for example, 4
C. and -3.degree. C.).

Next, when the user puts the food 21 on the metal plate 20 in the freezing compartment 18 and presses the quick freeze switch 24 for the purpose of freezing and storing the food 21, the compressor 9 and the blower 1
1 is continuously operated for a predetermined time Tmin (for example, 180 min), cold air is continuously introduced from the cold air discharge port 22 of the freezing chamber 18, and the food 21 is comparatively combined with the heat conduction cooling effect of the metal plate 20 on the bottom surface. Freeze in a short time. Then, after a lapse of a predetermined time, the operation returns to normal stable operation.

[0007]

However, in the above-mentioned structure, when the quick freeze switch 24 is pushed, the compressor 9 and the blower 11 are continuously operated for a predetermined time, and the food 21
Since it is an indirect cooling method that continuously cools the outer surface of the unit with a constant amount of cold air, it has the drawback that the freezing time is longer than the direct cooling method that promotes freezing by heat conduction cooling using a dedicated cooler. It was

Further, since a certain quick-freezing operation is carried out regardless of the size and shape of the food 21 to be frozen, the initial temperature, etc., for example, food having a large volume, food having a large thickness, or high initial temperature. As shown in FIG. 7, in the case of foods, the freezing time unevenness in the individual foods 21 becomes large, and the substantial passage time of the maximum ice crystal formation zone, which is a measure of the freezing quality, becomes long. That is, for example, while the initial temperature is 20 ° C., the surface portion where the freezing proceeds most quickly in the food 21 has already reached −1 ° C. immediately before entering the maximum ice crystal formation zone, whereas the progress of the freezing progresses most. The late center is still around 10 ° C., and the time difference between the two at the time of passing through the maximum ice crystal formation zone is further widened, and as a result, the final freezing time of the food 21 is long.

It takes a long time to pass through the maximum ice crystal production zone, so that the size of the ice crystals generated in the food becomes large, and the cells grow mainly outside the cell to damage the cell tissue and deteriorate the quality of the food. Let In addition to this, if the freezing time unevenness becomes large, ice crystals of various sizes will be mixed and present in the food, and relatively large ice crystals will have a high vapor pressure in the vicinity during frozen storage. There is a problem that it absorbs small ice crystals and water (water that remains without freezing even at normal freezing temperature) and grows further, promoting tissue destruction and protein denaturation of cells and further degrading food quality. It was

Further, since a certain quick-freezing operation is performed regardless of the initial temperature of the food, the refrigerator internal temperature, the outside air temperature, etc., as shown in FIG. The freezing operation may be terminated without completely passing through the crystal formation zone). When the initial temperature is high (in summer, home freezing after cooking, etc.), when the doors are opened / closed frequently, the temperature inside the refrigerator is high immediately after defrosting, or when the outside air temperature is high during summer and there is not enough cooling capacity. The cases increase. On the contrary, the initial temperature is low (in winter or freezing foods in refrigeration), the temperature inside the refrigerator is low (such as when following the last freezing), and the outside temperature is low in winter. In some cases, there is a problem in that useless rapid freezing operation is continued even though it has already been frozen.

In view of the above-mentioned problems, an object of the present invention is to perform efficient quick freezing with little quality deterioration regardless of environmental conditions, temperature and size of food.

[0012]

In order to solve the above-mentioned problems, the refrigerator of the present invention is provided with a damper device in the cold air inflow portion of the quick freezing compartment defined by the heat insulating wall and is mounted on the metal plate on the bottom surface. The process of quick freezing operation is provided with a compressor in which the first temperature detecting means for detecting the food temperature and the second temperature detecting means for detecting the air temperature installed in one screen of the quick freezing chamber are provided. And forcibly operating the blower,
A soaking process for stabilizing the food temperature to about -1 ° C by the output of the second temperature detecting means, and subsequently, forcibly opening the damper device while the compressor and the blower are forcibly operated, and And a control means constituted by a freezing process step for canceling the forced operation of the compressor and the blower based on the output of the second temperature detecting means.

[0013]

According to the present invention, when food is put in the quick freezing chamber and the quick freezing operation is started, the compressor and the blower enter the forced operation in the soaking process for a certain time, and the second temperature is set. The damper device is controlled to open and close according to the output of the detection means, and the cold air inflow amount is adjusted to keep the food temperature at about -1 ° C.
Almost stabilize. At this time, the temperature unevenness inside the food is uniformed regardless of the size of the food and the initial temperature. Next, in the freezing process, the compressor and blower are forcibly operated as they are,
By forcibly opening the damper device, sufficiently cooled cold air is continuously sent into the quick freezing chamber. At this time, since the food is soaked to about -1 ° C just before entering the maximum ice crystal formation zone, unevenness in passing time through the maximum ice crystal formation zone is reduced and the freezing time is also shortened substantially. Also, the first
Since the forced operation is canceled based on the output of the second temperature detection means, efficient freezing can be performed.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. The same components as those of the conventional one are designated by the same reference numerals, detailed description thereof will be omitted, and only different portions will be described.

Reference numeral 25 is a quick freezing chamber (hereinafter referred to as a quick freezing chamber 25), which is partitioned and formed in the lower portion of the freezing chamber 6 by a heat insulating wall 26 and a heat insulating door 27 that can be opened and closed. Reference numeral 28 is a cold air inlet to the freezing compartment 25, 29 is a cold air inlet, and the cold air inlet 28 is provided with a damper device 30 (hereinafter referred to as an electric damper 30) for adjusting the cold air inflow amount. The electric damper 30 is normally open. Reference numeral 31 denotes a metal plate such as aluminum which forms the inner wall of the freezing chamber 25 with four surfaces (top surface, bottom surface, both side surfaces), and a plurality of cool air discharge ports 32 are formed above both side surfaces. Reference numeral 33 denotes a cold air discharge port provided on the back surface of the quick freezing chamber 25, which communicates with the cold air discharge port 32 to a cold air passage 34 formed inside the heat insulating wall 26. The cooling passage 34 communicates with the electric damper 30.

Reference numeral 35 is a first temperature sensor fixed to the back side of the bottom surface of the metal plate 31 in a heat conductive manner, and reference numeral 36 is a first temperature sensor provided on the top surface of the freezing chamber 25 so as to detect the air temperature. Two
Temperature sensor. 37 is food 21 to be frozen
It is a freezing plate made of metal such as aluminum, which is mounted on the metal plate 31 so that the plate can be placed in and out freely. Next, the control relationship will be described. 38 is a control means including a microcomputer (hereinafter referred to as a microcomputer 38)
In the quick freezing operation time, the timer 39 that counts the constant control time T1 (for example, 120 min) of the soaking process and the timer 4 that counts the time safe time T2 (for example, 120 min) of the subsequent freezing process.
0, etc. are built in.

At the input terminal of the microcomputer 38, a temperature detecting means 41 having a temperature sensor 15 for the freezing compartment, a temperature detecting means 42 having a temperature sensor 16 for the refrigerating compartment, and a temperature detecting means having a temperature sensor 17 for the low temperature compartment are provided. Means 43 and first of the freezing compartment
The first temperature detecting means 44 having the temperature sensor 35 and the second temperature detecting means 45 having the second temperature sensor 36 are connected, and the output terminal includes the compressor 9, the blower 11,
Electric dampers 13, 14, 30 for refrigerating room, low temperature room, and freezing room
Drive means 46, 4 such as an electromagnetic relay for driving
7, 48, 49, 50 and a rotation speed control means 51 for changing the rotation speed of the blower 11 by switching the capacities of operating capacitors (not shown) are connected.

In such a structure, normally, the temperature detecting means 41 based on the temperature of the temperature sensor 15 in the freezer compartment carries out the intermittent operation of turning the compressor 9 and the blower 11 on and off, and the freezer compartment 6 The freezing chamber 25 is maintained at a predetermined temperature (for example, -20 ° C). At this time, the rotation speed control means of the blower 11 operates so as to keep the normal rotation speed.

On the other hand, temperature detecting means 42, 43 based on the temperatures of the temperature sensors 16, 17 in the refrigerating room and the low temperature room.
The electric dampers 13 and 14 are controlled to be opened and closed to adjust the inflow amount of cold air, and the refrigerating chamber 7 and the low temperature chamber 8 are cooled and maintained at predetermined temperatures (for example, 4 ° C. and −3 ° C.).

Next, the operation at the time of rapid freezing will be described with reference to the flowchart of FIG. 4 and the time chart of FIG.

First, when the food 21 to be frozen is placed on the freezing plate 37 and placed on the metal plate 31, the food 21
Is quickly conducted through the freezing dish 37 and the metal plate 38, and the temperature of the first temperature sensor 35 rapidly rises. Then, in STEP 1, it is determined whether the temperature of the first temperature sensor 35 is higher or lower than a predetermined value t1 ° C. (for example, 0 ° C.), and if it is low, the process waits until it rises in STEP 1. STEP1
If it is determined that the temperature is high in, the freezing operation control is automatically started.

When the control is started, first, the temperature equalizing process is started, and in STEP 2, the timer 39 starts counting for a fixed time. Following this, in STEP 3, the compressor 9 and the blower 11 are continuously operated, and the electric damper 30 of the freezing compartment is controlled to open and close based on the output of the second temperature detecting means 45. That is, depending on the temperature of the second temperature sensor 36,
The damper 30 is controlled to be opened / closed at predetermined values t2 and t3 ° C. to adjust the inflow amount of cold air so that the temperature in the freezing chamber 25 is substantially stabilized at about −1 ° C. just before entering the maximum ice crystal production zone of food. To work.

Then, in STEP 4, it is judged whether or not the count time of the timer 39 has reached T1 min, and if it has reached, the temperature soaking process is terminated at that point and the process proceeds to STEP 5. If it has not arrived, in STEP 4 a certain time T1 mi
Wait until n is reached. At this time, within a certain time T1 m
Within the range of in, the temperature of the food 21 is substantially uniform, and various correlations are preliminarily set so as to be stabilized at about -1 ° C as a whole.

Further, the temperature of the food 21 is -1 within T1 min.
Even if the temperature is substantially stable at 0 ° C, the soaking process is continued until T1 min, so the compressor 9 and the blower 11 continue to operate continuously, and the cold air is cooled to a sufficiently low temperature.

At the same time when the soaking process is finished, the freezing process is started, and in STEP 5, the timer 40 starts time counting. Following this, in STEP 6, the compressor continues to be forcedly operated, and the rotation speed control means 51
Acts, the operating capacitor (not shown) is switched to a high capacity, and the blower 11 is operated at high speed. Further, by forcibly opening the electric damper 30 of the quick-freezing chamber 25, a large amount of cold air having a high cooling power that has been cooled down and is on standby is continuously introduced into the quick-freezing chamber 25. And it progresses to STEP7.

In STEP 7, the temperature sensor 16 in the refrigerator compartment is
It is judged whether the temperature is higher or lower than a predetermined value t4 ° C. (for example, 10 ° C.). On the other hand, if it is determined to be high, STEP 8 is bypassed and the electric damper 13 is controlled by normal temperature control.

When STEP 8 is passed or bypassed, the routine proceeds to STEP 9, where it is judged whether the temperature of the temperature sensor 17 in the low temperature chamber is higher or lower than a predetermined value t5 ° C. (for example, 5 ° C.). The electric damper 14 is forcibly closed. On the other hand, if it is determined to be high, STEP 10 is bypassed and the electric damper 14 is controlled by normal temperature control.

Thus, the electric damper 1 for the refrigerating room and the low temperature room
When 3 and 14 are forcibly closed, the amount of air blown to the freezing chamber 25 increases correspondingly, and the cooling capacity is relatively increased because the refrigerating chamber 7 or the low temperature chamber 8 is not cooled. At this time, the food 21 has a plurality of cold air outlets 32 on both sides of the freezing compartment,
And that the cooling air from the cold air discharge port 33 on the back side is totally cooled, and at the same time, the conduction cooling from the bottom surface of the metal plate 38 inside the quick freeze chamber and the radiation cooling from the top surface and both side surfaces are added. During the time of the soaking process, the temperature of the cooler 8 is lowered by continuous operation of the compressor 9, and colder air having a lower temperature is given, so that the freezing proceeds intensively and rapidly.

Further, the food 21 is soaked at about -1 ° C. immediately before the maximum ice crystal formation zone, and the maximum ambient temperature ice crystal formation is suppressed by the above-mentioned total surrounding cooling while suppressing the freezing time unevenness depending on the site. Pass through the belt. This also contributes to increasing the freezing rate. That is, conventionally, the freezing process is slowest in the food product 21 and the freezing process is still at a positive temperature (for example, 10 ° C.) when the surface portion has already reached −1 ° C., and as a result, the maximum formation of ice crystals in the whole is achieved. This is because the central part, which has delayed the passage time of the strip, is aligned with the start line at -1 ° C as with the surface part by the soaking treatment. Since the freezing speed is greatly increased in this way, the ice crystals generated in the food 21 are suppressed to a small extent and the cell tissue is less likely to be damaged, so that protein denaturation, drip outflow after thawing, and texture such as texture are impaired. Deterioration of food quality is suppressed.

Next, at STEP 11, it is judged whether or not the count time of the timer 40 has reached T2 min, and if not, the routine proceeds to STEP 12. In STEP 12, the temperature of the first temperature sensor 35 is a predetermined value t6 ° C (for example, -15 ° C).
It is judged whether it is higher or lower, and if it is higher, the process returns to STEP 7 and the operation is repeated. When it is determined in STEP 12 that the temperature is low, the process proceeds to STEP 13. In STEP 13, the temperature of the second temperature sensor 36 is a predetermined value t7 ° C (for example, -15).
C)) or lower, and if higher, return to STEP 7 and repeat the operation. When it is determined in STEP 13 that the temperature is low, the process proceeds to STEP 14.

On the other hand, if the count time of the timer 40 has reached T2 min in STEP11, then STEP is left unchanged.
Proceed to 14.

In STEP 14, the forced operation of the compressor 9, the forced operation of the blower 11 at high rotation, and the forced closed state of the electric dampers 13 and 14 in the refrigerating compartment and the low temperature compartment are released,
The electric damper 30 of the quick freeze compartment is maintained in an open state.
Then, the freezing process step automatically ends, and at the same time, a series of quick freeze operation control ends.

That is, when the first temperature sensor 35 having a correlation with the food temperature and the second temperature sensor 36 representing the ambient temperature in the freezing chamber 25 have reached a certain low temperature state, the food product In No. 21, it is judged that it has completely passed through the maximum ice crystal production zone and the freezing is completed, and the quick freezing operation is terminated, and the frozen storage is directly started. Therefore, the quick freeze time is not insufficient and the wasteful quick freeze operation is not performed, and the most efficient quick freeze operation is automatically selected according to the state of the food 21 and the environmental conditions. It is very easy to use.

In this way, the food 21, which has been automatically frozen, has a high freezing speed and a small unevenness, so that the size of the ice crystals formed in the individual is small and distributed uniformly. , It is difficult to promote recrystallization growth of ice during frozen storage. Therefore, damage to cell tissues and protein denaturation are suppressed, and frozen storage with little deterioration in food quality becomes possible. The longer the storage period is, the wider the quality difference from the conventional one tends to be, and the long-term frozen storage can be used with good quality, and the degree of freedom of eating habits is also increased.

[0035]

As described above, according to the refrigerator of the present invention, the following effects can be obtained.

(1) In order to advance the freezing in a form in which the unevenness of the freezing rate in the food is suppressed by carrying out the soaking process which is substantially stabilized at about -1 ° C immediately before the maximum ice crystal formation zone before the freezing process. , The freezing speed of the food as a whole becomes faster.
Further, since the compressor and the blower are forcibly operated for a certain period of time during the soaking process, low-temperature cold air is concentrated and given in the freezing process, so that the quick freeze time can be set short.

(2) The size of the ice crystals produced is small and uniform due to the shortening of the freezing time by the soaking treatment and the suppression of the freezing time unevenness in the food individual. Moreover, deterioration of food quality due to cell damage due to ice recrystallization during frozen storage is small, and long-term frozen storage is possible.

(3) Since the quick freezing operation is automatically terminated based on the outputs of the first and second temperature detecting means, efficient and lean quick freezing can be performed.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a refrigerator showing an embodiment of the present invention.

FIG. 2 is an enlarged view of a plane cross section of a quick freezing compartment provided in the refrigerator of FIG.

FIG. 3 is a control block diagram of the refrigerator shown in FIG.

FIG. 4 is a flowchart of quick freezing control of the refrigerator shown in FIG.

5 is a time chart of quick freezing control of the refrigerator shown in FIG.

FIG. 6 is a vertical sectional view of a conventional refrigerator.

FIG. 7 is a time chart of quick freezing control of the refrigerator shown in FIG.

[Explanation of symbols]

 6 Freezing Room 7 Refrigerating Room 9 Compressor 10 Cooler 11 Blower 13, 30 Electric Damper (Damper Device) 25 Quick Freezing Room (Quick Freezing Room) 31 Metal Plate 32, 33 Cold Air Discharge Port 35 First Temperature Sensor 36 Second Temperature sensor 38 Microcomputer (control device) 41 Freezer temperature detecting means 42 Refrigerating room temperature detecting means 44 First temperature detecting means 45 Second temperature detecting means 51 Rotation speed controlling means

Claims (1)

[Claims] 1. A compressor, a cooler, a freezer compartment, a refrigerating compartment, a temperature detecting means for detecting a temperature in the both compartments, which constitutes a refrigerating cycle, and a heat insulating wall provided in an area of the freezer compartment. , A blower for forcedly blowing the cool air cooled by the cooler to the freezer compartment, the refrigerating compartment, and the quick freezer compartment, and cold air inflow provided at the inlets of the refrigerating compartment and the quick freezer compartment. A damper device for adjusting the amount, a metal plate provided at least on the bottom surface in the quick freezing chamber, a first temperature detecting means for detecting the temperature of food placed on the metal plate, and a temperature in the quick freezing chamber During the quick freezing operation, the second temperature detecting means for detecting the temperature is forced to operate the compressor and the blower, and based on the output of the second temperature detecting means, the food temperature is approximately -1 ° C. With a constant temperature soaking process to stabilize Then, while the compressor and the blower are forcibly operated as they are, the damper device of the quick freezing chamber is forcibly opened, and the forcible operation is canceled based on the outputs of the first and second temperature detection means. A refrigerator comprising control means for freezing food by a freezing process.