JPS5822068Y2 - refrigerator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a direct-cooled refrigerator in which the wall surface of the freezer compartment is constituted by a cooler, and more particularly to a refrigerator in which frost is formed in the freezer compartment primarily on a specific cooling surface.

It is well known that in conventional direct-cooled refrigerators in which the wall of the freezer compartment is made up of a cooler, when the door is opened, humid outside air enters the freezer compartment, causing frost to form on the inside of the freezer compartment, that is, on the entire inner surface of the cooler. It is being

For this reason, a defrost heater is attached to the cooler to defrost it, but when defrosting, it is necessary to remove the food from the freezer compartment to prevent adverse effects such as deterioration of the food due to heat or defrost water. There is.

Therefore, it has been difficult to perform periodic automatic defrosting using a timer system or the like.

The present invention was made to eliminate the above drawbacks,
The purpose of this is to concentrate frost on a specific cooler surface that is unlikely to come into contact with stored items in the refrigerator, and to configure the system so that the defrosting water flows down naturally in a specific direction. To provide a refrigerator that is free from the risk of deterioration of stored items due to defrosting heat and defrosting water even when executed in a stored state, and therefore enables defrosting operation regardless of whether stored items are stored. be.

Hereinafter, the present invention will be specifically explained in detail by way of an example.

1 to 6 for explaining the embodiment, FIG. 1 shows the basic configuration of a refrigerator to which this invention is applied.

In FIG. 1, reference numeral 1 denotes a heat insulating box having a heat insulating layer 5 formed between an outer box 2 and a freezer 3 and an inner box 4 housed therein, and the inside of the freezer 3 is a freezing chamber 6. The inside of the inner box 4 is a refrigerator compartment 8 that is cooled by an evaporator (cooler for the refrigerator compartment) 7.

9 is a compressor, 10 is a condenser, and 11 and 12 are doors for opening and closing the freezer compartment 6 and the refrigerator compartment 8, respectively.

In addition, 13 is a drain pipe that penetrates the partition insulation wall 14 that isolates the freezer compartment 6 and the refrigerator compartment 8, and 15 is a water receiving gutter that receives water flowing down through the drain pipe 13 and guides it to the outside of the refrigerator. It is.

As shown in FIG. 2, the freezer 3 has plastic side plates 16 and 17 forming the left and right side walls of the freezing chamber 6.
and a first cooler 18 forming the lower wall of the freezer compartment 6;
The second cooler 19 also forms the upper wall and the rear wall, and both the coolers 1B and 19 have retaining grooves 20a, 20a and 20b formed inside the upper and lower sides of the side plates 16 and 17, respectively.
, 20b, the left and right edges of each cooler 18 and 19 are inserted into and held in engagement with the coolers 18 and 20b, thereby forming a box-like shape as a whole, as shown in FIG.

Water receiving guide portions 21a and 21b, which are inclined downwardly to the rear, are protruded inward from the lower portions of the inner surfaces of the side plates 16 and 17 that are connected to the ceiling surface portion of the second cooler. In the second cooler 19, the front edge is connected to the upper part 23 of the front opening edge of the heat insulating box 1 via a thermally insulating frame 22 made of plastic, and the ceiling surface portion 19a excluding the front edge is tilted rearward. The inclination angle θ is approximately 10 degrees.

The second cooler 19 further has a back surface portion 19b that is bent in a hanging shape from the rear end of the ceiling surface portion 19a, and the lower edge of the back surface portion 19b is provided with water that extends in a substantially square shape from side to side when viewed from the front. The rainwater receiving stages 24 and 25 are formed by a bending means so as to protrude toward the front part, and the lowest parts of the rainwater receiving stages 24 and 25 are bent in a hanging shape so as to face each other. V
A drain cutout 26 is formed on the back surface 19b to form a continuous space in the shape of a letter.

- At the rear end of the first cooler 18, a rear surface portion 27 is formed by bending so that the upper edge thereof contacts the bent surface of the water receiving step portion 24.25. A drain port 28 is formed by a cutout in the middle portion of the drain hole 28, into which the mutually opposing hanging ends of the water receiving step portions 24 and 25 are inserted.

29 is a second cooler 19o) An evaporation pipe in which a refrigerant flow path is formed by a roll-pond force type or a pipe-on-sheet type arranged on the ceiling surface part 19a, and 30 is an evaporation pipe provided in the first cooler 18. These pipes are used to evaporate the liquid refrigerant passing through the pipes and produce a cooling effect.
In order to keep the set temperature of the second cooler 19 at least 5° C. lower than that of the first cooler 18, the total volume of the evaporation pipe line 29 is set larger than that of the evaporation pipe line 30. .

At this time, in particular, the evaporation pipe line 30 of the first cooler 18 is arranged to have a denser distribution in the part where the ice tray is placed than in other parts.

In this embodiment, the internal volume of the freezer compartment is 60 g, the internal volume of the evaporation pipe 29 of the second cooler 19 is 300, and the internal volume of the evaporation pipe 30 of the first cooler 18 is 10.
occ.

Reference numeral 31 denotes a first defrosting heater, which is attached to the second cooler 19 so as to span the front and left and right sides of the ceiling surface t19a.

A second defrost heater 32 is attached to the back surface 19b of the second cooler 19 so as to be distributed approximately evenly, and a third defrost heater 33 is attached to the center near the front of the ceiling surface section 19a. will be established.

In this embodiment, the first defrost heater 31 and the third defrost heater 33 are arranged such that the ratio of the total output of the first defrost heater 31 and the third defrost heater 33 to the output of the second defrost heater 32 is approximately 3:7. Defrost heater 31
The output of the third defrosting heater 33 is 25W, and the output of the third defrosting heater 33 is 5W.
Furthermore, the output of the second defrosting heater 32 is set to 70 to 80 W, respectively.

Other components necessary for realizing the present invention are listed in the fifth section.
Although they are shown in the refrigeration cycle system diagram in the figure and the control circuit diagram in Figure 6, the specific arrangement relationship between them can be easily understood with the following explanation, so please refer to Figures 1 to 3. The illustration of is omitted.

In the refrigeration cycle shown in FIG.
4. The compressor 9 is supplied to the compressor 9 through the solenoid valve 35 serving as a refrigerant flow path control means, the evaporator 7 in the refrigerator compartment 8, the connecting pipe 36, the first cooler 18, the communicating pipe 37, and the second cooler 19 in the above order. An auxiliary capillary tube 34 a is connected to the inlet 9 b and further connected between the outlet of the main capillary tube 34 and the inlet of the second cooler 19 .

A control circuit for controlling this refrigeration cycle is shown in FIG.

In this Fig. 6, 38 is an AC power supply with busbars 39 and 40 connected to both ends, and the -power busbar 39 detects the temperature inside the freezer compartment 6 and turns off when the temperature reaches the set temperature or lower. The other power bus 40 is connected via the detection switch 41, the conductor 42, the normally closed contact 44 of the relay 43, the compressor motor 45 that drives the compressor 9, the conductor 46, and an overcurrent protection switch 47 that turns off in response to an overload current. Connect to.

The bus bar 39 is also connected to a conductor 46 via a first contact 49 and an electromagnetic valve 35 of a refrigerating room temperature detection switch 48 that detects the temperature of the refrigerating compartment 8, which turns on when the temperature exceeds a set temperature. A second contact 50 of the switch 48, which turns on when a temperature lower than the set temperature is detected, is connected to the bus bar 40 via a connecting pipe heater 51 and a drain pipe heater 52 in parallel.

The connecting pipe heater 51 is provided on the connecting pipe 36 to prevent freezing on the outer surface thereof, and the drain pipe heater 52 is provided on the drain pipe 13 to prevent the freezing phenomenon. be.

The normally open side contact 53 of the relay 43 is connected to the first defrost heater 31, the second defrost heater 32, and the third defrost heater 33.
A defrosting heater group 54 that is arranged in parallel, a temperature fuse 55 that is cut off when the temperature of the freezer 3 rises abnormally, and a defrosting completion temperature that is turned off based on the completion of defrosting of the second cooler 19 when the temperature rise is detected. It is connected to the bus bar 40 via a switch 56.

57 is a defrosting timer which is equipped with a timer switch 58 and is connected between the conducting wire 42 and the bus bar 40; 59 is a relay coil, one end of which is connected to the normally open side contact 53 and connected to the timer switch 58; The other end is connected to a common connection point between the defrosting heater group 54 and the temperature fuse 55.

In the above, the defrosting timer 57 is configured to repeatedly close the timer switch 58 for a short time once every predetermined time.

Note that the time at which the timer switch 58 is activated varies depending on the season, etc., but in this embodiment, it is set to operate approximately once every 24 hours on average.

Further, the inner surface of the second cooler 19 is subjected to alumite treatment to improve hydrophilicity.

The temperature fuse 55 is located at the front center P of the second cooler 19.
1, and the defrosting completion temperature switch 56 is located near the bottom P2 of the back surface portion 19b, which is the lower end of the defrosting water flow.

Next, the operation of the above configuration will be explained.

First, when the internal temperatures of the freezer compartment 6 and the refrigerator compartment 8 are higher than the set values, the freezer room temperature detection switch 41 is turned on, the first contact 49 of the refrigerator room temperature detection switch 48 is turned on, and the loop 43 is turned on.
The normally closed side contact 44 of is turned on.

Therefore, the solenoid valve 35 is energized and open.
Also, the compressor motor 45 is being operated.

In this state, the liquid refrigerant discharged from the condenser 10 passes through the evaporator 7, the first cooler 18, and the second cooler 19 in series in this order via the main capillary tube 34 and the electromagnetic valve 35.

In this case, since the resistance of the auxiliary capillary tube 34a is greater than the resistance of the series refrigerant passage consisting of the solenoid valve 35, evaporator 7, and first cooler 18, liquid refrigerant hardly passes through the auxiliary capillary tube 34a.

In this way, the evaporator 7 and the freezer 3 produce a cooling effect, and the internal temperatures of the freezer compartment 6 and the refrigerator compartment 8 are gradually lowered. When the refrigerator compartment 8 is cooled to the set temperature, the refrigerator room temperature detection switch 48 is activated. is detected and the second contact 50 is switched on.

Then, the electromagnetic valve 35 is closed due to power cutoff, and instead of this, the connecting pipe heater 51 and the drain pipe heater 52 are energized.

When the solenoid valve 35 is closed as described above, the liquid refrigerant discharged from the main capillary tube 34 passes through the auxiliary capillary tube 34a and is transferred to the second cooler 1 of the freezer 3.
9, and cooling of the freezer compartment 6 continues.

When the freezing chamber 6 reaches the set temperature or lower, the freezing room temperature detection switch 41 is turned off in response to this, and the compressor motor 4 is turned off.
5 is cut off, and one cooling cycle operation by the compressor 9 is completed.

Then, when the temperature inside the freezer compartment 6 reaches the set temperature or higher, the freezing room temperature detection switch 41 is turned on, so the compressor 9 is operated again and the above-mentioned interior temperature control is started.

In such a refrigeration cycle, of the first cooler 18 and the second cooler 19, the second cooler 19 prevents the liquid refrigerant from passing through the solenoid valve 35 or the collapsed auxiliary capillary tube 34a. , and the total volume of the evaporator line 29 is set larger than that of the evaporator line 30 of the first cooler 18, so that the temperature is always 5° C. or more lower than that of the first cooler 18. Therefore, when humid outside air enters the freezer compartment 6 due to opening of the opening/closing door 11, the first cooler 18
A phenomenon occurs in which more frost is formed on the second cooler 19, which has a lower temperature, than on the second cooler 19, and at this time, a slight amount of frost may also form on the first cooler 18. The frost is transferred to the second cooler 19 by a sublimation phenomenon.

Next, a description will be given of melting and removing the frost that has adhered to the second cooler 19 as described above.

That is, since the defrosting timer 57 is energized only while the freezing room temperature detection switch 41 is on, it constantly accumulates the operating time of the compressor motor 45, and each time the total time reaches 24 hours, the timer switch 58 is shortened. Repeat closing time.

When the timer switch 58 is closed, the relay coil 59 is energized and its normally open contact 53 is turned on, so that the relay 43 is maintained in this state and the compressor motor 45 is de-energized.

As a result, during the self-holding period of the relay 43, the defrosting heater group 5
4, that is, the first defrost heater 31 and the second defrost heater 32
The third defrosting heater 33 is energized to perform a defrosting operation of the second cooler 19 which is in the frosting state, and the defrosting water is supplied to the second cooler 19 when the inclination angle θ is approximately lO. The water flows down to the back surface 19b along the slope of the ceiling surface 19a determined by the water flow without falling on the way, and then flows down the back surface 19b to the drain port 28 while being guided by the water receiving step 24.25. From there, the water flows through the drain pipe 13 to the water receiving gutter 15.
be guided by.

Preventing water from falling on the way down the ceiling surface part 19a as described above is further ensured by alumite treatment on the inner surface of the second cooler 19, and by making the water receiving stages 24 and 25 face each other. Water is effectively drained from the hanging portion by the drain cutout 26.

When the adhesion box to the second cooler 19 is removed in the above manner, the surface temperature of the second cooler 19 will rise rapidly, so the defrosting completion temperature switch 56 that detects the surface temperature is turned off. Therefore, the self-holding of the relay 43 is released and returns to normal, the defrosting heater group 54 is cut off, and the refrigeration cycle is returned to normal operation.

In the freezer compartment 6 controlled as described above, frost is mainly formed on the upper second cooler 19 that is less likely to come into contact with stored items, and the ceiling surface portion 19a of the second cooler 19 is frosted. The structure is such that the defrosting water is tilted downwardly backward to allow the defrosting water to naturally flow down to a specific area to prevent it from dripping into the freezing chamber 6, and a water receiving guide is provided on each side plate 16 and 17 of the freezer 3. 21a and 21b are provided, and the defrosting water flowing down from the ceiling surface part 19a of the second cooler 19 along the side plates 16 and 17 is transferred to the water receiving guide part 2.
1a and 21b are received along the slope of the back part 19.
Since the structure is such that the stored items are guided to b and finally discharged outside the refrigerator, even if the defrosting operation is performed with stored items stored, there is no chance that the stored items will directly receive defrosting heat or come into contact with defrosting water. Therefore, it is possible to prevent deterioration of stored materials due to defrosting operation.

Therefore, as in the above embodiment, regardless of whether stored items are stored or not, the defrosting operation is periodically executed by the defrosting timer 57 to create a state in which the average amount of frost is constantly reduced. This makes it possible to adopt a method of improving the cooling efficiency of the freezer 3.

As described above, the present invention can provide a refrigerator that can prevent stored items from being deteriorated by defrosting heat and defrosting water even if the stored items are defrosted while being stored.

In particular, according to the embodiment (because the lli is made of a heat insulating material such as plastic, it is possible to reliably maintain the temperature difference between the two coolers, and it is also possible to provide defrosting heat only to the second cooler. It is possible to prevent the defrosting heat from being consumed by the first cooler and to reduce the output of the defrosting heater.

[Brief explanation of the drawing]

1 to 6 relate to an embodiment of the present invention, in which FIG. 1 is a vertical sectional side view of a refrigerator, FIG. 2 is an exploded perspective view of a freezer,
FIG. 3 is a front view of the freezer, FIG. 4 is an exploded view of the second cooler, FIG. 5 is a configuration of the refrigeration cycle, and FIG. 6 is a wiring diagram of the control circuit. In the figure, 1 is a heat insulation box, 3 is a freezer, 6 is a freezing chamber, 7 is an evaporator, 8 is a refrigerator compartment, 9 is a compressor, 10 is a condenser, 16 and 17 are side plates, 18 is a first cooler, 1
9 is a second cooler, 19a is a ceiling surface part, 19b is a back part, 21a, 21b are water receiving guide parts, 24, 25 are water receiving stages, 28 is a drain port, 29.30 is an evaporation pipe line, 31 is a first defrost heater, 32 is a second defrost heater, 33 is a third defrost heater, 34 is a main capillary tube, 35 is a solenoid valve, 41 is a freezing room temperature detection switch, 43 is a relay, 4
5 is a compressor motor, 48 is a refrigerating room temperature detection switch, 54 is a group of defrosting heaters, 56 is a defrosting completion temperature switch, and 57 is a defrosting timer.

Claims (1)

[Claims for Utility Model Registration] (1) A first cooler forming a lower wall of the freezer compartment; a second cooler, a defrosting heater provided in the second cooler, and a first cooler that engages with the left and right end portions of the second cooler to form left and right side walls of the freezer compartment.
11[ii] A water receiver is formed at a lower part of the engagement part of the side plate with the ceiling surface part of the second cooler and receives the defrosting water from above and guides it in a predetermined direction. A refrigerator. 2. The refrigerator according to claim 1, wherein the side plate is made of a material having heat insulating properties.