JPS60138381A - Refrigerator structure - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] Field of Application of the Invention The present invention is directed to a refrigerator having a refrigerator compartment on the lower side and a freezer compartment on the upper side. This invention relates to a refrigerator structure, in particular, a refrigerator in which a predetermined vacuum pump is connected to the vacuum space so as to prevent the vacuum degree of the vacuum space formed inside the heat insulating wall from decreasing over time. This invention relates to a structure.

BACKGROUND OF THE INVENTION As is well known, every household has a refrigerator, and there are also commercial refrigerators in restaurants, etc., and refrigerators are installed in open showcases in supermarkets, etc., and are widely used. It has been adopted.

According to this type of refrigerator, which is extremely widely used for home use, as shown in FIG. A heat insulating wall 3 defines upper and lower freezer compartments 4.5, each of which can be sealed and opened with vinegar 6.7.

The low-temperature, low-pressure gas refrigerant is converted into a high-temperature, high-pressure gas refrigerant by the compressor 8 installed at the bottom of the refrigerator 1, and is then pumped to the surrounding area of the refrigerator 1 by the radiator 9 installed at the top of the refrigerator 1. The gas refrigerant is cooled and expanded under reduced pressure by a capillary tube (not shown), which is a decompression mechanism, and is sent to the refrigerator cooler provided deep within the freezer compartment 4. The cooler 10 cools the air that is being circulated by the fan 11 inside the refrigerator 1 and supplies it for refrigeration and cooling action, and the refrigerant sent out from the cooler 10 returns to the compressor 8 again to start the refrigeration cycle. It is made to circulate.

Therefore, the internal temperature of the seed cold R storage 1 is designed to be maintained at around -18°C in the freezer compartment and around +3°C in the refrigerator compartment. However, the ambient concentration around the refrigerator 1 is generally high due to the temperature of the surrounding air itself and the temperature rise due to heat radiation from the radiator 9.

Therefore, due to physical phenomena, heat input from the outside to the refrigerator 1 through the heat insulating wall 2, etc. is unavoidable. A heat insulating material with a low temperature is added as an intervening filling to suppress heat input from the outside.

However, the intrusion of external heat due to the addition of a mechanical insulation material to the seed box has already reached its limit due to the fact that 17 tons of material is required, and the running cost of the refrigerator 1 or There were problems in terms of operational efficiency, thermal efficiency, etc., which had already reached their limits.

To deal with this problem, as shown in Japanese Patent Application Laid-Open No. 58-78082, there is a method in which the heat insulating wall of the refrigerator is filled with a partially vacuum-backed heat insulating material;
As shown in Japanese Patent No. 6279, a new physical insulation technology has been developed in which the inner and outer walls of the insulating wall of the refrigerator 1 are made into a vacuum space.

In addition, the vacuum space of the adiabatic compressor that exists in the extreme vacuum space is filled with a conventional heat insulating material with the lowest possible thermal conductivity, so that both
At the same time, technology has been improved to further improve insulation performance.

However, in a refrigerator having the seed space insulation wall, for example, the thermal conductivity is 0.00 at a vacuum degree of 0.1 Torr.
Although it is better to use a heat insulating product with a rating of 3W/m"C, such a degree of vacuum, that is, good heat insulation, can be obtained at the initial stage of cold i-rin manufacturing, so even if it is theoretically possible, it is not effective. The drawback was that the above was impossible.

In other words, the useful life of a refrigerator is usually 10 years or more, and even if the vacuum adiabatic compressor of the refrigerator maintains the vacuum space at the above-mentioned degree of vacuum, the wall structure and assembly It is unavoidable that air molecules remain on surfaces, welded surfaces, bends, etc. Therefore, over time, these remaining air molecules will gradually fly out and reduce the vacuum level, which will cause the above-mentioned initial There is a problem that the good insulation properties of the product are realized, and there is also the problem that there may be slight distortion during movement or transportation after manufacturing, during packaging, during installation, or during movement by the user after installation. In addition to this, extremely small leakage gaps may be formed at bent or assembled parts due to severe drought changes, etc., and these factors combine to cause damage over many years. There was a problem in which the degree of vacuum could not be avoided.

<Object of the Invention> The object of the present invention is to solve the technical problem of the thermal insulation performance of the refrigerator based on the above-mentioned conventional technology, especially the problem of the deterioration of the thermal insulation performance of the vacuum insulation wall over time, and to During the service life of the refrigeration cycle, the degree of vacuum in the vacuum space of its vacuum insulation wall should always be maintained as designed in order to ensure that its thermal efficiency is maintained as designed and similar to that at the initial stage of manufacture. It is an object of the present invention to provide an excellent refrigerator structure that can be maintained and is beneficial to the field of cold and heat utilization in the energy industry.

<Summary of the Invention> In accordance with the above-mentioned object and the gist of the above-mentioned claims, the structure of the present invention is such that, in order to solve the above-mentioned problems, a refrigerator generates a predetermined freezing cycle using a compressor, a radiator, and a cooler. During the initial manufacture of the refrigerator, the vacuum space formed within the insulation wall is heated to 1T.
It is possible to create a set vacuum level of less than 1 Torr and connect it to a vacuum pump via a check valve, and then increase the pressure to more than 1 Torr via a pressure lens facing into the vacuum space within the insulating wall. When detected, the vacuum pump is operated for a predetermined period of time to maintain the initial degree of vacuum, or the vacuum pump is stopped operating at every set time via a timer, and the vacuum pump is operated via a predetermined operating device. A technology that uses a vacuum pump to maintain the same degree of vacuum as the initial vacuum, thereby ensuring that the insulation of the vacuum insulation wall is maintained for the lifetime of the refrigerator, equivalent to that of the refrigeration cycle. The measures taken were as follows.

<Embodiment - Configuration> Next, an embodiment of the present invention will be explained as follows based on the drawings from FIG. 2 onwards. Note that the same parts as in FIG. 1 will be explained using the same reference numerals.

Although the illustrated embodiment is a household refrigerator, as will be described later, the present invention is applicable to commercial refrigerators such as restaurants,
It can also be applied to the market's O, Punsho case freezers, etc.

In Fig. 2.3, reference numeral 1' denotes the refrigerator of the present invention, which includes insulating walls 2' at the top, bottom, left and right, and back, and extends integrally from the insulating walls 2' at the back and is integrated with those on the left and right. The insulating wall 3' which is fixed to the wall is formed into a groove layer as will be described in detail later, and as in the conventional case, the extending insulating wall 3' forms a freezing compartment 4 and a refrigerating compartment 5 above and below. It is constructed like this, and on its entire surface, doors 6 and γ, which can be opened and closed in a sealed manner, are installed at the top and bottom.

Further, the following compressor 8 installed in the machine room 13 at the lower part of the refrigerator 1' is connected to the cooler 10 installed at the back of the freezer compartment 4 via the radiator 9 at the upper part. The container 10 is connected to the wall 8 by piping, and performs a refrigeration cycle in the same way as in the conventional embodiment shown in FIG. A motor 11 installed at the top rotates a fan 12 provided at the top of the freezer compartment 4 to circulate the air inside the cold refrigerator.

The structure described above is substantially the same as that of the conventional refrigerator 1.

Therefore, in the lower machine room 13 of the refrigerator 1', the second
．． 3.4 As shown in Figure 4, a closed casing 14 is installed.The casing has a partition wall 15 inside and is divided into two chambers, one side of which has the above-mentioned chamber. The compressor 8 has a refrigerant gas suction pipe 1G and a discharge pipe 17.
A motor 18 is provided to connect the partition wall 15 and has an electromagnetic coupling 19 to the partition wall 15.

Further, in another chamber of the partition wall 15 inside the casing 14, a normal oil rotary type vacuum pump 20 as shown in FIG. 8 is installed. Another electromagnetic coupling 19' that is excited and demagnetized by a relay device (not shown) is provided on the partition wall 15 side.
The motor 18 is provided opposite to the electromagnetic coupling 19 via the motor 9 .

Further, on the other side of the pump 20, there is a suction pipe 22 which is connected to the vacuum space inside the heat insulating wall 2' through a switching valve 21, which will be described in detail next, as shown in FIG. 2
3, and an exhaust pipe 24 is connected so that its tip faces into the machine room 13.

As shown in FIG. 5, the heat insulating wall 2' is made by bending an outer plate 25 and an inner plate 26 made of metal with a predetermined thickness into a predetermined shape parallel to each other at a predetermined interval at their ends. They are molded and welded together to form a vacuum space 27 therebetween.

The lower part of the vacuum space is connected to the switching valve 21 via a connecting pipe 28, and is connected to the vacuum space 27 as shown in FIG. In order to avoid deformation of the plate 25 and the inner plate 2G, a honeycomb y spacer 29 with a set thin pressure is explained, and between them, a material with as high thermal conductivity as possible, such as pearlite, is used. A small heat insulating material 30 is interposed and filled.

Although not shown in the drawings, the spacer 29 is assumed to have a small hole bored therein so that the cells communicate with each other and negative pressure is conducted therebetween.

Further, the switching valve 21 is connected to the suction pipe 2 of the pump 20.
1 to the refrigeration cycle as described later.
A draw tube 31 used for initial evacuation is attached so that it can be switched and connected.

In addition, 32 is a valve for vacuum packing, and is a valve used when vacuum packing foodstuffs and the like stored in the refrigerator 1' to maintain freshness and prevent water evaporation.

In the above configuration, when shipping the refrigerator 1' manufactured in a factory in this way, a refrigerant such as Freon 12, etc. is sealed in each mechanical part of the freezing cycle and in the piping.
Naturally, when the refrigerant is sealed, air is present in each mechanical part and the piping, so if the refrigerant is sealed as it is, problems will occur in the sealing.

Therefore, it is necessary to draw out the air in advance, but the switching valve 21 is switched to the handling pipe 31 side as shown in FIG. 5, and the refrigeration cycle piping mechanism is connected to the pump 20 via the suction pipe 22 as shown in FIG. Connect as shown.

Then, the electromagnetic coupling 19 is connected via a relay (not shown).
．． 10' are connected electromagnetically and the motor 18 is operated, the compressor 8, the radiator 9, the radiator 9, the cooling tube 33, the cooler 10, and the air flow through these pipes, as shown in FIG. All internal air is extracted from the extraction pipe 31 and suction pipe 2.
2 by a pump 20, exhausted by an exhaust pipe 24, and evacuated to a predetermined level.

Therefore, if a predetermined amount of Freon 12 or the like as the refrigerant is sealed, the pump 20 of the refrigerator 1' can be used for filling the refrigerant.

After the refrigerant gas is sealed into the refrigeration cycle system as described above, the switching valve 21 is connected to the exhaust pipe 29 and the suction pipe 21, and the motor 18 is operated. All air is evacuated via pump 20.

In this case, the degree of vacuum in the vacuum space 27 is 1To.
rr or less, preferably 0.2T Orr or less, and when the pressure reaches the setting 1-or, r, a sensor (not shown) as a predetermined operating device detects this and activates the electromagnetic clutch 19' via a relay. At the same time, the motor 18 is stopped.

Note that in this stopped state, the check valve 23 operates, and the outside air will not flow back into the vacuum heat insulating wall 2' again. - Also, the fact that the negative pressure is distributed in the vacuum space 27 in all the vacuum insulating walls 2' means that the inner and outer panels 25, 26' of the vacuum insulating walls 2'
This is ensured by a group of small holes (not shown) of a honeycomb-shaped spacer 29 interposed therein.

The degree of vacuum in the vacuum space 27 within the vacuum insulation wall 2' is I T
orr, preferably 0.2 orr, because when the pump 20 is installed and put into use as described in detail below, the vacuum insulation wall 2'' is always maintained by the predetermined operation over time.
This is to maintain the degree of vacuum of the refrigerator 1' and to maintain optimal operating efficiency and thermal efficiency of the refrigerator 1'.

That is, this will be explained based on theory and experiments using Figure 9.10. First, Figure 9 shows the pressure and power characteristics of the vacuum pump 20, with the horizontal axis representing the pressure and the vertical axis representing the power. As shown in the figure, the power consumption of the characteristic curve varies somewhat depending on the temperature of the oil, but as the pressure is lowered, that is, from the right side to the left side in the figure, the characteristic curve becomes approximately Power consumption increases up to 300 Torr,
As the pressure is lowered from then on, f disappears [power also decreasesζ,
I understand.

If the pressure drops below 1 Jorr, especially 0.2
It is known from the diagram, theory, and experiment that there is almost no change in the characteristics at a vacuum pressure lower than Torr.

Therefore, the characteristic of a vacuum pump is that the working pressure is 1 T
It can be seen that the power consumption hardly changes when orr is 0.2 T orr or less.

It can also be seen that the power consumption can be maintained at a minimum for the number of vacuum pumps 20 in use.

On the other hand, as shown in Figure 10, the relationship between vacuum degree and heat insulation is that if the pressure is plotted on the horizontal axis and the thermal conductivity is plotted on the vertical axis, if the pressure decreases as shown in the curve shown in the diagram, that is, from the fabric side in the diagram. It is known that the thermal conductivity decreases as it moves to the left.

In particular, it has been found that the thermal conductivity decreases rapidly from 102 Torr to 10-2 Torr, and in particular, the thermal conductivity decreases rapidly near 1 Lorr.

Therefore, in this invention, the vacuum l! 7i thermal wall 2 thermal 2' In order to lower the degree of vacuum in the internal space 21 to prevent heat from entering from the outside, improve the thermal efficiency of the refrigerator 1', and maintain the initial degree of vacuum, vacuum pump 2
In order to operate 0 at predetermined intervals over time, it is of course desirable to increase the degree of vacuum in the vacuum space 21 and to reduce the power consumption of the vacuum pump 20 used there as much as possible to keep the operating cost 1 economically low. It is.

Therefore, as mentioned above, based on Figure 9.10, 1lo
At a negative pressure lower than rr, the consumption horn of the vacuum pump 2° hardly changes, is suppressed to the lowest level, and its thermal conductivity drops most rapidly, which is a good combination of the two. As can be seen from Figure 10, the rate of change at which the thermal conductivity rapidly decreases is 0.2.
lorr, and since the power consumption starts at about 0.2 TOrr, the critical negative pressure for that pressure is (theoretically and experimentally) it is desirable to set it at 1.2 TOrr. I understand it too.

Therefore, in this invention, as shown in FIG. 11, a pressure sensor 34 as a well-known predetermined operating device is placed facing the internal vacuum space 21 of the heat insulating wall 2' when shipped from the factory. and set this to 1T orr~O, :)T
It is set and connected to the determination circuit 3G of the microcomputer 35 so that it is energized when the pressure exceeds orr.

Therefore, at the time of shipment, the vacuum insulation wall 2 of the refrigerator 1'
When the vacuum space 27 of ' is kept at the above-mentioned 1 to 0.2 TOrr state and handed over to the user and used for actual operation after being installed in a specified manner, the vacuum space 27 of The degree of vacuum in the internal vacuum 1!127 of the heat insulating wall 2' decreases, and the degree of vacuum is constantly detected by the pressure sensor 34.
is detected by the determination circuit 36 of the microcomputer 35.
Since the negative pressure in the vacuum space 21 is energized, the negative pressure in the vacuum space 21 is set to a negative pressure degree of 1 to 02. As soon as the value rises above 1, the determination circuit 3G determines that the value is outside the set value, and causes the motor 18 to orbit via a predetermined relay circuit, and also excites the electromagnetic coupling 19 to activate both electromagnetic clutches 19.1.
9' is linked to rotate the vacuum pump 20, sucking in the residual air inside the heat insulating wall 2' through the suction pipe 22, and exhausting it around the refrigerator 1' through the exhaust pipe 24 to lower the degree of vacuum. .

Then, the degree of vacuum is 1 to 0.5T o
When rr is reached, the pressure sensor 34 detects the degree of vacuum, energizes it, determines that it is within the set value in the determination circuit 3G, turns off the motor 18, and turns off the electromagnetic coupling 19.
' is demagnetized and the vacuum pump 20 is stopped.

Note that once a predetermined degree of vacuum is reached, the check valve 23 of the suction pipe 22 operates, so that outside air does not enter the vacuum space 27 of the heat insulating wall 2'.

Since the pressure sensor 34 constantly monitors the degree of vacuum in the vacuum space 21 inside the heat insulating wall 2', the degree of vacuum is completely automatically maintained at the set value of 1 to Q, 2T Orr. The thermal insulation properties of the insulation wall 2' remain as designed, ie, the same as the initial state.

Moreover, the heat insulation property is not only maintained through the low thermal conductivity due to the constant degree of vacuum of the vacuum wall 9, but also through the insulation of the inner and outer panels 25.2.
It is also supported by a heat insulating material 30 such as perlite, which is filled between the holes 6 and 1.

Further, deformation due to the negative pressure in the vacuum space 27 is sufficiently ensured by the honeycomb-shaped spacer 29 shown in FIG. 6 and by the filled heat insulating material 30.

In addition, for the refrigeration cycle operation of the refrigerator 1', the motor 1
8 directly connects the compressor 8 to suck refrigerant gas through the pipe 1G;
Of course, it can be circulated through the discharge pipe 11 to perform the freezing and refrigeration function in the same manner as in the past.

Therefore, although only one motor 18 is provided in the casing 14, it is used independently to maintain the vacuum level of the refrigeration cycle and the vacuum insulation wall 2', and may also be used simultaneously Even if they are operated in parallel, there is no problem.

Furthermore, in the above embodiment J3, the vacuum in the vacuum space 21 of the vacuum insulation wall 2' is automatically maintained via the pressure sensor 34, but the embodiment shown in FIG. As in the example, a timer 34' is provided in place of the pressure lens in the microcomputer 35', and for example, -
The vacuum pump 20 is operated via the electromagnetic coupling 19, 19' of the motor 18 at a predetermined time of about 5 minutes once a day to periodically and automatically evacuate the vacuum space 27, so that the vacuum space 27 is always evacuated at a predetermined level. It is also possible to maintain the degree of vacuum below 1 to 0.2-Orr. In this case, the determination circuit 36' of the microcomputer 35' determines whether or not the energization by the timer has elapsed for the set time. This means that the driving operation of the vacuum pump 20 is controlled.

When using this type of timer usage, the above-mentioned first
In the embodiment using the pressure horn sensor shown in FIG. 1, a timer may be attached to the operation of the pressure sensor 34 to control the operation for a certain period of time after the vacuum pump 20 is activated.

Furthermore, in the embodiment shown in FIG. 13, and in the above-described embodiment shown in FIG.
In order to prevent the leakage of insufficient refrigerant from the compressor 8 side of the refrigeration cycle, the first
As shown in Figure 3, the vacuum pump 20 is directly connected to the motor 18 via the drive shaft 38 by providing a reliable seal 37 on the partition wall 15, thereby preventing leakage of refrigerant gas and improving the structure. A simpler version is also possible, as shown in FIG. 14, in which the left and right chambers are completely defined through the partition wall 15, and each chamber is provided with an independent motor 18, 18'. By directly connecting the compressor 8 and the vacuum pump 20, leakage of refrigerant gas is completely prevented, the degree of vacuum of the vacuum insulation wall 2' is reliably maintained, and the operation of the refrigeration cycle is completely independent of the compressor 8 and the vacuum pump 20. It is also possible to do so.

Furthermore, in each of the above-mentioned embodiments, a vacuum space is formed inside the insulating wall on both the upper and lower sides of the refrigerator and the back of the refrigerator, and the forced exhaust is performed. It is also possible to adopt a mode in which the sealing is performed via a swivel joint as appropriate.

Furthermore, the fruit of this invention/Il! Of course, the embodiment i is not limited to the above-mentioned embodiments. For example, a refrigeration cycle can be implemented by directly connecting the motor of a compressor for one-cycle refrigeration to a vacuum pump without providing a timer or pressure sensor, etc. Various modes can be adopted, such as forcing and automatically evacuating the vacuum space of the vacuum insulation wall at the same time so as to always maintain a negative pressure at or below the set degree of vacuum.

Furthermore, as mentioned above, the refrigerator to which the present invention is applied is applicable not only to household refrigerators but also to general commercial refrigerators and freezers in open showcases in supermarkets.

<Effects of the Invention> According to the present invention, basically, a vacuum space is formed inside the heat insulating wall of a refrigerator for general household, commercial, or business use to achieve a predetermined degree of vacuum. By maintaining this, the insulation performance can be lowered by an order of magnitude compared to the insulation walls of conventional refrigerators, which are simply interposed with insulation material, improving the thermal efficiency and operating efficiency of the refrigerator. The effect of being able to do this is produced.

Since the vacuum space of the insulated wall of the refrigerator once installed can be evacuated to a specified level by a vacuum pump connected to the vacuum space within the vacuum insulated wall, the initial shipment is always maintained during the service life of the refrigerator. Time 4! The degree of vacuum in the vacuum space of the IS-built insulation wall is maintained, and therefore the excellent effect of maintaining the designed thermal efficiency and operating efficiency is achieved.

Therefore, even if an initial vacuum is created unavoidably, there will be air molecules remaining in the vacuum space, or even if the vacuum level in the vacuum space decreases due to insufficient air entering from the outside. The effect is that the degree of vacuum can be restored to the original level.

Further, the vacuum pump connected to the vacuum space is operated in a predetermined manner by a predetermined operation device, so that the vacuum pump is operated at a predetermined time interval or at a predetermined pressure or higher,
Therefore, the electric power required to maintain the vacuum insulation capacity of the vacuum insulation wall for 1t31 hours is minimized, and the running cost is also reduced.

In addition, since the vacuum pump is operated via a predetermined operation device in this way, automatic maintenance of the vacuum pump can be performed periodically or irregularly by operating the vacuum pump, and its durability is the same as that of the refrigerator. The effect of being made equal is also produced.

In addition, this refrigerator also has the effect that the temperature of the freezer compartment and the refrigerator compartment can be maintained at the same initial freezing and refrigeration temperature over a service life due to the above-mentioned improved vacuum insulation performance.

In addition, by providing a vacuum pump in the refrigerator, it can not only be used to exhaust the vacuum space of the vacuum insulation wall, but also when the initial refrigerant is sealed in the refrigeration cycle diameter, the air in the system can be evacuated using the vacuum pump. This also has the effect of allowing the refrigerant to be filled afterwards, and also eliminates the need for troublesome work such as bringing in another vacuum pump, especially when refilling the refrigerant after maintenance or during maintenance inspections. There are also benefits.

[Brief explanation of drawings]

FIG. 1 is a schematic sectional view explaining the structure of a heat insulating wall of a refrigerator based on the prior art, FIG. is a cutaway side sectional view of the same part, FIG. 4 is a sectional view of the drive part of the vacuum pump and motor, and FIG. 5 is a partial enlarged sectional view of the vacuum insulation wall.
Fig. 6 is a partial front view of the heat insulating material, Fig. 7 is a schematic diagram when refrigerant is filled in, Fig. 8 is a schematic structural cross-sectional view of the vacuum pump,
Figure 9 is a graph explaining the relationship between vacuum pump pressure and power consumption, Figure 10 is a graph explaining the relationship between pressure and thermal conductivity, Figure 11 is a control flow diagram of the vacuum degree of the vacuum insulation wall, and Figure 12 1 is a flowchart corresponding to FIG. 1 of another embodiment, and FIGS. 13 and 14 are partial sectional views corresponding to FIG. 4 of another embodiment. 1'...Refrigerator, 8...Compressor, 9...Radiator, 10...Cooler, 2'...Insulating wall, 27...Vacuum space, 20...Vacuum pump, 34.34'... Predetermined operating device (pressure sensor timer) 18... Motor Figure 1? Figure 5 Figure 13 Figure 37 Figure 14

Claims (1)

[Scope of Claims] (1) In a structure in which an insulating wall of a refrigerator in which a compressor is connected to a radiator and a cooler is an insulating wall that forms a vacuum space, the vacuum inside the insulating wall A refrigerator structure characterized by being provided with a space-connected vacuum pump. (2) The refrigerator structure according to item 1 of the patent specification, wherein the vacuum pump is linked to the motor of the compressor. (3) In a refrigerator in which a compressor is connected to a radiator and a cooler, the insulating wall of the refrigerator is an insulating wall that forms a vacuum space, and a vacuum pump connected to the vacuum space within the insulating wall is installed. A cold storage structure characterized in that the vacuum pump is connected to a predetermined operating device. (4) The predetermined operating device is a pressure sensor of ITor or more. The refrigerator structure according to claim 2. (5) The refrigerator structure according to claim 2, wherein the predetermined operating device is a timer.