JPH0535345B2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a refrigerator-freezer, and in particular, to a refrigerator that is capable of reliably preventing the temperature inside the freezer from rising during defrosting, despite its simple configuration. Regarding refrigerator-freezers.

[Technical background of the invention and its problems]

Conventionally, in a refrigerator-freezer equipped with a freezer compartment and a refrigerator compartment, there are two methods for cooling the interior of the freezer compartment: a direct cooling method in which a cooler is placed directly inside the freezer compartment, and a direct cooling method in which a cooler is housed inside the freezer compartment separately from the freezer compartment. A cooling room is provided, and a cold air convection method is adopted in which the air in the freezing room is circulated through the cooling room using a convection fan.
There is a so-called intercooling method. Since the intercooling method uses a cold air convection method, it has the advantage of uniformly cooling the inside of the freezer compartment in a short period of time.

By the way, even in the case of the above-mentioned intercooling type refrigerator-freezer, it is still necessary to remove frost from the surface of the cooler installed inside the cooling chamber as needed.

Generally, such defrosting from the surface of the cooler is
This is done by heating the cooler with an electric heater for defrosting, but in conventional intercooled refrigerator-freezers, convection occurs between the freezing compartment and the cooling compartment during defrosting. As a result, the temperature inside the freezing chamber rises, resulting in a problem that food and the like cannot be stored in the freezing chamber.

Therefore, in order to eliminate such problems,
Recently, a rotatable damper plate has been installed in the connecting path connecting the freezing room and the cooling room to open and close this connecting path.
A refrigerator that prevents convection between the freezing chamber and the cooling chamber by controlling the damper plate to close during defrosting, thereby suppressing the temperature rise in the freezing chamber during defrosting. A refrigerator is suggested. In the case where a damper plate is provided as described above, a drive mechanism using a shape memory alloy is used as a means for driving the damper plate.

However, as mentioned above, it is equipped with a damper plate,
Additionally, refrigerator-freezers equipped with drive mechanisms using shape memory alloy materials have the following problems.
That is, in order to heat the shape memory alloy material to the transformation point temperature or higher in a short period of time, a large capacity electric heater for controlling the damper is required. Using a large-capacity electric heater like this allows the damper plate to be closed in a short time, but on the other hand, the damper plate is heated more than necessary during the defrosting period, and as a result, the temperature inside the freezer compartment increases due to the above heating effect. There was a problem. Therefore, it is possible to use a low-capacity electric heater for damper control, but in this case, it takes a long time for the damper plate to close, and during this time the air heated by the defrosting electric heater is There was a problem with the liquid flowing into the freezer.

[Purpose of the invention]

The present invention was made in view of the above circumstances, and its purpose is to operate the damper plate reliably and in a short time with low electric capacity using a drive mechanism using a shape memory alloy material. To provide a refrigerator-freezer which can reliably prevent the temperature inside a freezing chamber from rising during defrosting.

[Summary of the invention]

The present invention provides forcible circulation of air in the freezing chamber through a cooling chamber containing a cooler during steady operation, and during defrosting to remove frost adhering to the cooler. In a refrigerator-freezer in which the refrigerant supply is stopped and the cooler is heated with a defrosting electric heater,
a rotatable damper plate provided in a communication path that communicates the freezing chamber and the cooling chamber to open and close the communication path; a bias spring for constantly applying a biasing force in the opening direction to the damper plate; A drive spring made of a shape memory alloy material that drives the damper plate in the closing direction against the bias spring when heated above a transformation point temperature, and an electric heater for damper control that selectively heats the drive spring. and a drive spring storage container that accommodates the damper control electric heater and the drive spring and limits a spatial area heated by the damper control electric heater to a peripheral area of the drive spring. It is characterized by becoming.

〔Effect of the invention〕

With the above configuration, the control electric heater and the drive spring made of a shape memory alloy material are housed in the drive spring container, and the drive spring container drives the spatial region heated by the damper control electric heater. Since the heat is limited to the area around the spring, the heat generated by the electric heater for damper control can be effectively used to heat the drive spring, improving heating efficiency and heat retention, and heating the drive spring effectively and quickly. It can be heated to Therefore, the damper plate can be quickly switched to the closed state, and the electric capacity of the damper control electric heater can also be reduced. In addition, since the damper control electric heater is housed in the drive spring storage container, the radiant heat from the electric heater energized during defrosting is shielded by this container, preventing the damper plate from being heated more than necessary. There is no.

In addition, if a ventilation hole is provided in the wall of the drive spring storage container to an extent that does not impede the heating characteristics when the electric heater for damper control is energized, when the refrigeration cycle operation is started after defrosting, the inside of the drive spring storage container will be The warm air is quickly removed by natural convection, resulting in instant cooling of the drive spring. Therefore, the responsiveness of the closing operation of the damper plate is not impaired.

Therefore, according to the present invention, the above-mentioned effects are combined, and it is possible to reliably prevent the temperature of the freezer compartment from rising during defrosting.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a diagram showing an example in which the present invention is applied to a refrigerator-freezer in which a freezer compartment and a refrigerator compartment are cooled by separate coolers.

In FIG. 1, 1 is a refrigerator-freezer housing;
This housing 1 is formed of a member that includes a heat insulator 2 and is elongated. The interior of the housing 1 is divided into upper and lower parts by a partition wall 3, and due to the presence of the partition wall 3, a freezing compartment 4 is located above and a refrigerator compartment 5 is located below.
are formed respectively. The side walls of the freezer compartment 4 and the refrigerator compartment 5 located on the same side are respectively formed into doors 6 and 7 that can be opened and closed.

A cooling chamber 9 is formed in the back wall 8 of the freezer compartment 4, and the upper end of this cooling chamber 9 is connected to a discharge outlet that opens at a position above the inner surface of the back wall 8 through a passage 10 formed in the back wall 8. The lower end of the cooling chamber 9 communicates with the outlet 11 , and the lower end of the cooling chamber 9 communicates with a suction port 13 opened on the upper surface of the partition wall 3 via a passage 12 formed in the partition wall 3 . A cooler 14 is installed within the cooling chamber 9. A sheathed heater 15 is attached to the cooler 14 and is energized only during defrosting. Also,
A convection fan 16 is installed inside the discharge port 11, and a damper mechanism 17 is installed inside the passage 10. In addition, inside the refrigerator compartment 5, the refrigerator compartment 5
A cooler (not shown) is installed to cool the inside.

Specifically, the damper mechanism 17 is configured as follows.

That is, 22 in the figure is a damper plate rotatably supported by the shaft 21 to open and close the passage 10. A support plate 23 and a support plate 24 are respectively fixed at positions facing the damper plate 22 on the inner surface of the cooling chamber 9. A locking wall 25 is provided at the lower end of the support plate 23, which can lock with the upper surface of the damper plate 22 when the damper plate 22 is in the closed state. A bias spring 26 is stretched between the center portion of the support plate 23 and the upper surface of the damper plate 22 for always applying a biasing force in the opening direction to the damper plate 22. On the other hand, a locking wall 27 is provided at the upper end of the support plate 24, which can lock with the lower surface of the damper plate 22 when the damper plate 22 is in the closed state. A damper drive mechanism 28 is provided on the inner surface of the support plate 24 at a position below the damper plate 22. The damper drive mechanism 28 is made of a material with relatively good thermal conductivity, and has relatively small diameter ventilation holes 3 in the upper and lower walls.
1 and 32 respectively and the passageway 10
container 33 whose volume is sufficiently smaller than the space volume of
and a driving spring which is stretched between the lower surface of the damper plate 22 and the lower end of the container with the coil portion accommodated in the container 33 and selectively applies a biasing force in the closing direction to the damper plate 22. 34, an electric heater 35 for controlling the damper which is housed in the container 33 and selectively heats the driving spring 34, and a good thermal connection between the outer surface of the container 33 and cooling fins of the cooler 14, for example. It is composed of a heat conductive plate 36 made of a heat conductive material. The drive spring 34 is made of a shape memory alloy material, and expands below the transformation temperature and contracts above the transformation temperature. Note that the sheathed heater 15 and the electric heater 35 are each connected to a defrosting control circuit (not shown).

The refrigerator-freezer of this embodiment configured as described above operates as follows.

That is, during normal cooling, the drive spring 34 of the damper drive device 28 is at a temperature below its transformation point, so it is in an extended state as shown in FIG. 2a. Therefore, the damper plate 22 is set to the open side by the spring force of the bias spring 26.
Now, when the temperature inside the freezing compartment 4 is lower than the set temperature of a not-shown thermostat installed in the freezing compartment 4, the fan 16 is driven. By this,
The air inside the freezer compartment 4 is supplied from the inside of the freezer compartment 4 to the suction port 13.
Passage 12 - Cooler 14 - Damper mechanism 17 - Passage 1
It circulates in the path from 0 to the discharge port 11 to the freezer compartment 4.
At this time, since the circulating air comes into contact with the cooler 14 and is cooled, the inside of the freezer compartment 4 is also cooled.

On the other hand, during defrosting, the defrosting control circuit stops the fan 16 and energizes the sheathed heater 15 and the electric heater 35 for damper control by energizing these heaters. The electric heater 35 and the drive spring 34 are installed in a container 33 with a sufficiently small volume.
is housed within. That is, the electric heater 35
The drive spring 34 is housed in a small-volume container 33 that limits the spatial area heated by the electric heater 35 to the peripheral area of the drive spring 34 . Therefore, when the electric heater 35 is energized, the temperature inside the container 33 rises rapidly. The drive spring 34 is heated not only by the heated air inside the container 33 but also by radiant heat from the electric heater 35 . Therefore, the drive spring 34 immediately reaches a temperature higher than its transformation point and contracts as shown in FIG. 2b. When the drive spring 35 contracts, the drive spring 35
is the damper plate 2 against the spring force of the bias spring 26.
2 is rotated in the closing direction, the passage 10 is blocked by the damper plate 22. As a result, the cooler 14
Warm air from the sheathed heater 15 for heating the freezer compartment 4
Inflow into the interior is blocked.

When defrosting is completed and the cooler 14 is restarted,
A difference is created between the temperature of the air around the cooler 14 and the temperature of the air inside the container 33. Since the container 33 has ventilation holes 31 and 32 on the top and bottom, the ventilation holes 3
Natural convection occurs through the tubes 1 and 32, and cold air is introduced into the container 33. On the other hand, since the container 33 is thermally connected to the cooler 14 via the heat conduction plate 36, the container 33 itself is also cooled by heat conduction. Therefore, the drive spring 34 is immediately cooled down and expanded again as shown in FIG. 2a. As a result, the damper plate 22 is rotated to the open side, and an air circulation path is formed. In this state, when the fan 16 is driven, the inside of the freezer compartment 4 is cooled.

In this way, according to this embodiment, the drive spring 34
An electric heater 35 heats the drive spring 34.
The drive spring 34 is housed in a small volume container 33 that limits the spatial area heated by the drive spring 34 to the surrounding area of the drive spring 34. Therefore, during defrosting, the drive spring 34 can be heated in a short time using a small capacity electric heater 35. It can be heated to a temperature higher than the transformation point temperature, and the damper plate 22 can be quickly controlled to the closed state. Therefore, the effects described above can be fully achieved.

It goes without saying that the present invention can also be applied to a cooler in which a single cooler cools both a freezing chamber and a cooling chamber, or a cooler in which a rapid cooling cooler is provided in the cooling chamber.

[Brief explanation of the drawing]

FIG. 1 is a vertical sectional view showing a part of a refrigerator-freezer according to an embodiment of the present invention, and FIGS. 2a and 2b are diagrams for explaining the operation of the refrigerator-freezer. 1...Housing, 2...Insulating material, 3...Partition wall, 4
... Freezer room, 5... Refrigerator room, 6, 7... Door, 8...
...Back wall, 9...Cooling room, 10, 12...Passway, 1
1... Discharge port, 13... Suction port, 14... Cooler, 15... Sheathed heater, 16... Fan, 1
7... Damper mechanism, 21... Shaft, 22... Damper plate, 23, 24... Support plate, 26... Bias spring, 28 ... Damper drive mechanism, 31, 32... Ventilation hole, 33... Container , 34... drive spring, 35...
...Electric heater, 36...Heat conduction plate.

Claims (1)

[Claims] 1. During steady operation, the air in the freezing chamber is forced to circulate through the cooling chamber in which the cooler is housed, and during defrosting, the air is forced to circulate through the cooling chamber in which the cooler is housed, and the above-mentioned forced circulation and cooling are performed. In the refrigerator-freezer, in which the supply of refrigerant to the refrigerator is stopped and the cooler is heated by an electric heater for defrosting, the connecting passage is provided in a connecting passage that communicates the freezing compartment and the cooling compartment, and the connecting passage is opened and closed. A rotatable damper plate that
A bias spring that always applies a biasing force in the opening direction to this damper plate, and a shape memory alloy material that drives the damper plate in the closing direction against the bias spring when heated above the transformation point temperature. a drive spring, a damper control electric heater that selectively heats the drive spring, and a spatial area that accommodates the damper control electric heater and the drive spring and is heated by the damper control electric heater. and a drive spring storage container that limits the drive spring to a peripheral area of the drive spring. 2. The refrigerator-freezer according to claim 1, wherein the drive spring housing container is made of a material with good thermal conductivity and is thermally coupled to the cooler.