JP3319787B2 - Refrigerator with thawing function - 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, and more particularly, to a refrigerator.
The present invention relates to a refrigerator having a circulation fan for forcibly circulating air in a refrigerator.

[0002]

2. Description of the Related Art Conventionally, as this kind of refrigerator with a thawing function, a refrigerator disclosed in Japanese Patent Application Laid-Open No. 2-157576 is known. The publication discloses a blower that circulates cool air in the refrigerator at a slight wind speed, and operates the blower (circulation fan) to prevent the temperature in the refrigerator from becoming uneven.

[0003]

In the above-described conventional refrigerator, since the air in the refrigerator is forcibly circulated, outside air easily enters even if the door is slightly opened. Therefore, even if the cooling mechanism continues to operate, the temperature in the refrigerator rises to a temperature unsuitable for storage.

[0004] The present invention has been made in view of the above problems, and has as its object to provide a refrigerator in which the temperature in the refrigerator does not rise significantly even when the door is opened halfway.

[0005]

In order to achieve the above object, the invention according to the first aspect is characterized in that the cool air generated by the cooling mechanism is circulated around the storage box by a blower fan so that the inside of the storage box has a predetermined temperature. A thawing function with a circulating fan for promoting thawing for forcibly circulating the air in the storage box by being driven at the time of thawing independently of the blower fan and for indirect cooling to the inside of the storage box, In the refrigerator,
Temperature detecting means for detecting the temperature in the storage box; and determining whether the inside of the storage box is out of the holding temperature range based on the temperature detected by the temperature detecting means. And stopping means for stopping the circulating fan after a lapse of time.

[0006]

[Action] In the invention of claim 1 constructed as described above, the temperature detecting means has detected the temperature in the storage box, stop means on the basis of the detected temperature at the temperature detecting means It is determined whether the inside of the storage box is out of the holding temperature range, and if the state outside the holding temperature range continues for a predetermined time, it is regarded as abnormal, and the circulation fan for promoting thawing is stopped. That is, when the temperature in the storage box rises out of the holding range due to the half-opening of the door, the stopping means detects this based on the detection result of the temperature detecting means and stops the circulation fan. When the circulation fan stops, the cooling air in the storage box and the air outside the storage box are not positively mixed, so that the amount of the cooling air leaking out is reduced and the temperature rise is also reduced.

[0007]

As described above, according to the present invention, since the forced circulation is stopped when the door is opened halfway, a refrigerator capable of preventing a state in which the temperature in the refrigerator rises sharply is provided. Can be provided.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. 1 is a front view of a refrigerator according to an embodiment of the present invention, FIG. 2 is a partially cutaway front view, FIG. 3 is a partially cutaway top view, and FIG. 4 is a cross-sectional view taken along the line IV-IV in FIG. In the figure, the refrigerator main body includes a heat insulating box 10 and a storage box 20, and the heat insulating box 10 is configured by filling a heat insulating material 13 such as urethane foam between an inner wall of an outer box 11 and an outer wall of an inner box 12. A pair of left and right openings 14a and 14b are formed on the front surface thereof, and heat insulating doors 15a and 15b for opening and closing the openings 14a and 14b are attached by hinges so as to be openable and closable. A support (frame member) 16 is formed between the openings 14a and 14b.

The storage box 20 is formed of a metal plate material such as stainless steel, which is a heat conductive member, in a housing shape having an opening 21 on one surface.
The openings 14a and 14b of the heat insulating box 10 are fixed to and supported by the outer peripheral edge of the inner surface of the front wall as desired. At this time, the left and right side walls 22, 23, the top wall 24, the bottom wall 25, and the rear wall 26 of the storage box 20 are respectively held at predetermined intervals from the inner wall of the inner box 12 in the heat insulating box 10, and the gap is formed by the air flow. A circulation passage W is formed. The bottom wall 2
5 is provided with a drain pipe 26a for draining dew condensation water, and has a drain cap (not shown) for shutting off outside air.

The two in-compartment fans 30a and 30b are each configured by fixing a fan 32 to the rotation axis of a fan motor 31 and attached to the left wall 22 via a support member so as to face the right wall 23. Have been. Further, a cover 40 for forming an air flow path is attached to the front surface of the in-compartment fans 30a, 30b.
An exhaust port 41 is formed at a portion facing the fan 32, and an intake port 42 is formed at a lower portion. That is, the end of the upper side of the cover 40 is in contact with the upper wall 24, the end of the left side bent as an L-shaped cross section is in contact with the left side wall 22 of the storage box, and the end of the right side is the rear wall of the storage box 20. 26, the lower side forms the suction port 42 with a predetermined gap from the left side wall 22.

The left side wall 2 of the storage box 20 in the heat insulating box 10
The evaporator 51 of the cooling mechanism 50 is fixed to the wall portion facing the upper surface 2 with its air flow path directed vertically, and the upper part between the evaporator 51 and the left side wall 22 of the storage box 20 has air A circulation hole 61 is formed, and a shielding plate 60 provided with a blower fan 62 is fixed to the air circulation hole 61 so as to hang down from the upper wall of the inner box 12 of the heat insulating box 10 at the upper side thereof. A sufficient gap is formed between the lower side of the shielding plate 60 and the lower wall of the inner box 12, and an air cooling flow path communicating from the gap to the upper air flow hole 61 via the air flow path of the evaporator 51. Is formed.

In the chamber RM, parallel to the upper wall 24,
Further, a dew condensation water capturing plate 28 shown in FIG. 5 is attached via a mounting bracket 29 also serving as a spacer at a small distance. The dew condensation plate 28 is a thin plate 28
a and 28b are held at a very small distance from each other, and a number of circular holes are formed in the lower thin plate 28b. In addition, a net shelf 33 shown in FIG. 6 is provided in two stages supported by the support 16 and the rear wall 26. Further, as for the bottom, a net shelf 34 with legs shown in FIG.
And a plate shelf 35 having a U-shaped cross section shown in FIG. A hole 35a is formed in the center of the plate shelf 35 so that it can be easily removed with a finger.

As shown in FIG. 9, the cooling mechanism 50 includes a compressor 52 for compressing the refrigerant, a condenser 54 for condensing the compressed refrigerant under the air cooling action of the air cooling fan 53, and a condenser 54 for condensing the refrigerant. A dryer 55 for dehumidifying the refrigerant, a capillary tube 56 for converting the dehumidified condensed refrigerant into a low-temperature and low-pressure refrigerant, and the evaporator for cooling by the heat of vaporization of the low-temperature and low-pressure refrigerant and supplying the vaporized refrigerant to the compressor 52 51 are housed in an auxiliary box 10a formed on the left side of the heat insulating box 10 except for the evaporator 51. A hot gas valve 57 is interposed between the output side of the compressor 52 and the input side of the evaporator 51. When the hot gas valve 57 is opened, the high-temperature compressed refrigerant compressed by the compressor 52 is discharged. And evaporator 51 is heated. Note that the hot gas valve 57 opens when energized and closes when not energized.

The compressor 52 includes a compressor motor 5
2a and a compression mechanism 52b driven by being connected to the rotation axis of the compressor motor 52a.
The drive of the compressor motor (CM) 52a is controlled by an electric control circuit 70 as shown in FIG. The electric control circuit 70 is connected to a temperature sensor Th that is disposed in the room RM and detects the internal temperature T,
The CPU 71 in the electric control circuit 70 executes a program corresponding to the flowcharts shown in FIGS. 11 and 12 based on the detected inside temperature T. Electric control circuit 7
0 is stored in the auxiliary box 10a, and the electric control circuit 70 has the temperature sensor Th and the compressor motor 5
Along with 2a (CM), fans 30a and 30b in the warehouse,
A push-button type selection switch SW for selecting the operation of the in-compartment fans 30a and 30b, an air-cooling fan (F) 53 of the cooling mechanism 50, and a hot gas valve (HV) 57 are connected. The selection switch SW is provided on the front surface of the auxiliary box 10a, and the temperature sensor Th may be provided in the air circulation path W.

Next, the operation of this embodiment having the above configuration will be described. When the power switch (not shown) is turned on after the refrigerator is installed, the CPU 71 starts executing the main program shown in FIG. First, the CPU 71 performs initial setting in step 100. For example, an initial value is introduced to a flag or a variable to be used thereafter, or the presence or absence of a device abnormality is detected. After the initial setting, the CPU 71
Starts the storage operation in step 110. In the storage operation, the operation of the cooling mechanism 50 is controlled such that the internal temperature T of the room RM is maintained between the upper limit temperature T1 and the lower limit temperature B1 of the storage temperature. For example, if the inside temperature T is higher than the upper limit temperature T1 when the cooling mechanism 50 is not operating, the cooling mechanism 50 is operated, and conversely, when the inside temperature T is the lower limit temperature when the cooling mechanism 50 is operating. If it is lower than B1, the cooling mechanism 50 is stopped. At other times, the current situation is maintained. At the time of cooling, the chamber RM is provided with an air circulation path
Is indirectly cooled by the cold heat of the cold air flowing through the air, and is maintained at a high humidity. In particular, although condensation easily forms on the upper wall 24, if it condenses and drops, it falls on the upper surface of the condensation water capturing plate 28.
Flow down to side 6. The water condensed on the dew condensation plate 28 is trapped between the two thin plates 28a and 28b, and evaporates when the humidity becomes low.

During the storage operation, the inside temperature T
Is maintained while rising and falling within the storage temperature range as shown in a period P1 in FIG. In the process of the storage operation, the above process is continued each time the process is passed, and the CPU 71 instructs execution of a predetermined process and executes a decompression routine of step 120. In this decompression routine, the CPU 71
Detects the operation status of the selection switch SW in step 200, and determines that the decompression has started if the selection switch SW has changed from on to off. Now, it is assumed that the user opens the heat insulating doors 15a and 15b and stores the frozen mass on the shelves 33 to 35. When the heat-insulating doors 15a and 15b are opened at the timing a, warm air outside the refrigerator enters and the temperature T inside the refrigerator rises. After closing the heat-insulating doors 15a and 15b at the timing b, the selection switch SW is pushed. Let go.

The CPU 71 detects in step 200 that the selection switch SW has changed from on to off, and in step 202, the in-compartment fan 30a, which is a thawing promoting means,
Activate 30b. The fans 30a and 30b in the same compartment blow air from the left side to the right side with the exhaust port 41 in the chamber RM as shown in FIG. 2, and the air exchanges heat when flowing along the surface of the frozen mass. And take the cold heat of the frozen mass while being cooled. The cooled air flows rightward and then downwards. When it flows under the net shelf 34 placed on the bottom wall 25, it is drawn into the plate shelf 35 side and enters the cover 40 through the suction port 42. The air exits through the exhaust port 41 again. Note that the air sent from the exhaust port 41 enters above the dew condensation water capturing plate 28 and flows to the right, so that the space on the dew condensation water capturing plate 28 also functions as a duct.

After operating the in-compartment fans 30a and 30b, the CPU 71 starts a timer counter in step 204. In this embodiment, the timer is configured in software by a timer count routine driven by a timer interrupt. For example, the CPU 71 sets a timer flag indicating that the timer is counting in step 204 and sets the timer flag as a variable. When the value of the prepared timer counter is cleared, in step 300 of the timer counting routine started at predetermined time intervals, it is determined whether or not the timer is counting by referring to the timer flag. If the timer flag is set, it is determined that counting is in progress, and the timer counter is incremented in step 302. Therefore, if the flag is set, the timer counter is incremented every time the timer interrupt is activated, and the timer can be counted.

On the other hand, if the count is not being performed, the CPU 71 determines in step 304 whether the abnormality flag is on. The abnormality flag is set to on in step 208 when the CPU 71 determines that the temperature is abnormal based on the inside temperature T in step 206 in the thawing routine. However, if the in-compartment temperature T is not abnormal, it is turned off in step 210, so the abnormal flag is usually off, and the CPU 71 ends the timer count routine without doing anything. As described above, the CPU 71 determines whether or not the internal temperature T is at an abnormal temperature in step 206. In this embodiment,
When the time during which the temperature exceeds the determination temperature TC higher than the upper limit temperature T1 is extended for a long time, it is determined that the heat insulating doors 15a and 15b are in the half-open state. Therefore, C
The PU 71 compares the inside temperature T with the discrimination temperature TC, and determines that the temperature is abnormal when the inside temperature T is higher.

Since the heat insulating doors 15a and 15b are opened at the timing b, warm air outside the refrigerator enters the chamber RM, and the temperature T in the refrigerator becomes higher than the discrimination temperature TC as shown in FIG. I have. Therefore, the CPU 71 executes step 2
At 06, it is determined that the temperature is abnormal, and at step 208, the abnormal flag is turned on. Next, the CPU 71 determines in step 212 whether the abnormal temperature has continued for a predetermined time or more. By turning on the abnormality flag, the value of the abnormality counter is increased in step 306 of the timer count routine. Therefore, the CPU 71 determines the duration of the abnormal temperature with reference to the value of the abnormality counter.

Initially, it is determined that the predetermined time has not been exceeded, and at step 214, it is determined whether or not the inside temperature T is within the storage temperature range. As described above, the internal temperature T
Is higher than the upper limit temperature T1 of the storage temperature range.
1 starts cooling by operating the compressor motor 52a and the air-cooling fan in step 218 through steps 214 and 216. At this time, the cooling flag is turned on. After starting the cooling operation, the CP
U71 determines in step 220 whether the cooling operation is being performed and the internal temperature T is lower than the lower limit temperature B1 of the storage temperature range based on the cooling flag and the internal temperature T. I do. Immediately after the start of the cooling operation, the internal temperature T is higher than the lower limit temperature B1, but the internal temperature T gradually decreases due to the cooling operation and the cooling of the frozen mass. While the temperature is higher than the lower limit temperature B1, the value of the timer counter is referred to in step 224, and if the predetermined expiration time tx has not passed, the process returns to step 206.

While performing the cooling operation, the inside fan 30
By operating a and 30b, the air in the refrigerator takes cold heat from the surface of the frozen mass, and the temperature T in the refrigerator gradually decreases. If the temperature becomes lower than the determination temperature TC at the timing c, the CPU 71 determines that the temperature is not abnormal in step 206, turns off the abnormality flag in step 210, and clears the abnormality counter. Then, the internal temperature T further decreases and the lower limit temperature B at the timing d.
If it becomes lower than 1, the CPU 71 stops the cooling operation in step 222 and turns off the cooling flag. Even if the cooling operation is stopped, the in-compartment fans 30a and 30b continue to blow the air in the incubator to the surface of the frozen mass, so that the in-compartment temperature T decreases for a while. However, on the side of the frozen mass, the inside of the refrigerator is cooled and the heat invading from outside the refrigerator is transmitted, so that the thawing gradually proceeds. Along with this, the decrease in the internal temperature T stops, and when it starts to rise,
In steps 216 to 222, the CPU 71 attempts to maintain the internal temperature T within the holding temperature range. When the value of the timer counter exceeds the predetermined expiration time tx, the CPU 71 stops the internal fan in step 226 and ends the thawing routine. In FIG. 13, a change in the core temperature of the frozen mass in the case of normal thawing is indicated by M1, and a change in the internal temperature T is indicated by a solid line.

By the way, it is assumed that when the frozen lump is stored, the heat insulating doors 15a and 15b are not closed properly but are opened halfway. In this case, although the air in the refrigerator is cooled by the cooling operation or the cold heat of the frozen mass, the fan 3 in the refrigerator is used.
Since 0a and 30b try to circulate the air inside the refrigerator,
The cooled air leaks out of the refrigerator, and air outside the refrigerator enters the refrigerator. As a result, although the internal temperature T decreases to some extent, as shown in FIG.
It stops at the above. During this time, the CPU 71 refers to the value of the abnormality counter in step 212 while instructing the cooling operation, and determines whether or not the predetermined time ty has elapsed. When the heat-insulating doors 15a and 15b are properly closed, the temperature has stopped at the abnormal temperature at the timing c before the same time ty has elapsed.
Since the cooling air is leaked aggressively by 30b, the internal temperature T remains at an abnormal temperature even at the timing c.

If the value of the abnormality counter exceeds the predetermined time ty at timing f, the CPU 71 stops the internal fans 30a and 30b at step 226. At this time, a warning may be issued in step 228 indicated by a two-dot chain line. When the in-compartment fans 30a and 30b stop, air does not actively circulate in the in-compartment, so that the amount of leaked cooled air and the intrusion of air outside the in-compartment also decreases. As a result, the temperature T in the refrigerator starts to decrease, enters the holding temperature range, and can be maintained only by refrigeration. The change in the internal temperature T of the frozen mass in such a case is indicated by a dashed line in FIG.

[0025]

[Brief description of the drawings]

FIG. 1 is a front view of a refrigerator according to one embodiment of the present invention.

FIG. 2 is a partially cutaway front view of the refrigerator.

FIG. 3 is a partially cutaway top view of the refrigerator.

FIG. 4 is a sectional view of the refrigerator.

FIG. 5 is a perspective view of a condensation water capturing plate.

FIG. 6 is a perspective view of a net shelf;

FIG. 7 is a perspective view of a net shelf with legs.

FIG. 8 is a perspective view of a plate shelf.

FIG. 9 is a diagram showing a configuration of a cooling mechanism.

FIG. 10 is a block diagram of an electric control circuit.

FIG. 11 is a flowchart corresponding to a program executed by a CPU.

FIG. 12 is a flowchart corresponding to a program executed by a CPU.

FIG. 13 is a diagram showing a temperature change by temperature control.

[Explanation of symbols]

Reference numeral 20: storage box, 30a, 30b: internal fan, 70: electric control circuit, 71: CPU, RM: room, SW: selection switch, T: internal temperature, TC: determination temperature, Th: temperature sensor.

Claims (1)

(57) [Claims] The cooling air generated by a cooling mechanism is circulated around a storage box by a blower fan to indirectly cool the inside of the storage box to a predetermined temperature, and is provided in the storage box independently of the blower fan. A refrigerator having a thawing function provided with a circulation fan for promoting thawing for forcibly circulating the air in the storage box by being driven at the time of thawing; and a temperature detecting means for detecting a temperature in the storage box; Stopping means for judging whether the inside of the storage box is out of the holding temperature range based on the temperature detected by the detecting means and stopping the circulating fan when the state outside the holding temperature range continues for a predetermined time. A refrigerator with a defrosting function, characterized in that: