DESCRIPTION REFRIGERATOR

TECHNICAL FIELD

The present invention relates to refrigerators with high energy conservation effect.

BACKGROUND ART

Refrigerators are known to be one of top-ranking electric home appliances that consume a measureable amount of power. This is because, unlike other electric home appliances, a refrigerator requires power continuously around the clock. Therefore, power-saving refrigerators are demanded for power conservation (energy efficiency) in ordinary households.

One of causes of large power consumption in refrigerators is a long-operation time of compressor or high-frequency driving due to temperature rise inside the refrigerator caused by the penetration of outside heat (hereafter referred to as "heat penetration") into a cabinet through insulated walls. Therefore, higher insulating performance of the cabinet results in less heat penetration from outside, and thus temperature rise inside the refrigerator can be suppressed. The operation time of compressor can thus be reduced or the compressor can be driven at low frequency, resulting in saving power.

In general, the cabinet is configured by filling expanded insulating material such as urethane foam between inner cabinet and outer cabinet. Simply-speaking, a thicker insulating material (thickness of insulated wall) demonstrates higher insulating performance. As is well known, the insulated wall is thickened to reduce heat penetration. In particular, the insulated wall is made thicker at a portion where the temperature around the cabinet and the temperature inside storage compartments greatly differ, so as to gain a greater effect of reducing heat penetration and save power.

On the other hand, sizes of kitchen and kitchen instruments in ordinary houses are standardized to some extent. Therefore, the space to install a refrigerator is limited in a way.

Furthermore, in line with increasing number of refrigerating and frozen food items as a result of recent changes in food habit, and increasing number of working housewives, ordinary household refrigerators tend to require a larger storage capacity.

Under the circumstances, a thicker insulated wall for saving power is against customers' demand. Power needs to be saved while securing the storage capacity without enlarging outer dimensions of
refrigerator.

Fig. 13 is a vertical sectional view of a basic structure of a mechanical compartment and its adjacent storage compartment of a conventional refrigerator. An insulated door is omitted.

As shown in Fig. 13, insulated partition 1 divides insulated cabinet 2 into multiple storage compartments. Storage case 3 for storing food is provided in each compartment.

Mechanical compartment 5 for disposing equipment such as compressor 4 is configured in a lower part at the back of insulated cabinet 2. Since compressor 4 generates heat during operation, a temperature inside mechanical compartment 5 is higher than that of other outer parts of insulated cabinet 2.

Accordingly, insulated wall 6 surrounding mechanical compartment 5, where a temperature difference with that inside storage compartment is large, has the greatest insulated wall thickness. On the other hand, a temperature difference between adjacent compartments is smaller compared to the temperature difference with outside insulated cabinet 2. Insulated partition 1 thus has the smallest insulated wall thickness.

As described above, the insulated wall thickness of the insulated cabinet is generally distributed based on the temperature difference between the outside and storage compartment in order to efficiently reduce heat penetration and save power on the premise that outer dimensions of refrigerator and storage capacity are kept the same. (For example, refer to PTL 1.)

In general, however, a door gasket is provided between a front opening and an insulated door, in order to prevent cold air from leaking out side. The front opening is formed by the insulated partition for thermally insulating between adjacent storage compartments, and side insulated walls and bottom insulated wall of the storage compartment.

A metallic reciever that tightly attaches to the door gasket is provided across inside and outside the storage compartment on the front face of insulated partition that forms the opening. Outside heat thus directly enters inside the storage compartment by thermal conduction of metallic reciever. If the thickness of insulated partition is small, the main stream of cold air circulating inside the storage compartment reaches close to the high-temperature metallic reciever, and thus thermal conductivity between the metallic reciever and cold air increases. As a result, heat penetration increases and larger power is consumed.
Accordingly, the insulated wall thickness needs to be distributed such that power can be comprehensively saved with consideration to the heat penetration from the opening in addition to the heat penetration through the insulated walls, i.e., the temperature difference with external air, on the premise that the outer dimensions of refrigerator and storage capacity are kept the same.

[Citation List] Patent Literature PTL 1 Japanese Patent Unexamined Publication 2006-200774

SUMMARY OF THE INVENTION

A refrigerator of the present invention includes an insulated cabinet, an insulated door for opening and closing a front face of an opening of the insulated cabinet, a storage compartment including the insulated cabinet and the insulated door, an insulated partition dividing the storage compartment into multiple storage compartments, and a mechanical compartment for housing a compressor. The mechanical compartment is provided at a lower part of the insulated cabinet. A thickness of the insulated partition is made thicker than that of an insulated wall provided between the storage compartment and the mechanical compartment. This offers a power-saving refrigerator that reduces heat penetration from external air to improve cooling efficiency on the premise that outer dimensions of refrigerator and a storage capacity are kept the same.

BRIEF DESCRIPTION OF DRAWINGS

Fig. 1 is a vertical sectional view of a refrigerator in accordance with a first exemplary embodiment of the present invention.

Fig. 2 is a vertical sectional view of a basic structure of a storage compartment adjacent to a mechanical compartment of the refrigerator in accordance with the first exemplary embodiment of the present invention.

Fig. 3 is a magnified sectional view of an upper part of an insulated door of the storage compartment adjacent to the mechanical compartment of the refrigerator in accordance with the first exemplary embodiment of the present invention.

Fig. 4 illustrates a general relationship between an amount of heat penetration and a thickness of insulated wall.

Fig. 5 illustrates a relationship between an amount of heat penetration into the storage compartment and a thickness ratio of insulated walls in the refrigerator in accordance with the first exemplary embodiment of the present invention.

Fig. 6 is a magnified sectional view of an upper part of an insulated door of a storage compartment adjacent to a mechanical compartment in a refrigerator in accordance with a second exemplary embodiment of the present invention.

Fig. 7 is a vertical sectional view of a basic structure of a storage compartment adjacent to a mechanical compartment in a refrigerator in accordance with a third exemplary embodiment of the present invention.

Fig. 8 is a magnified sectional view of a lower part of an insulated door of the storage compartment adjacent to the mechanical compartment in the refrigerator in accordance with the third exemplary embodiment of the present invention.

Fig. 9 illustrates a relationship between an amount of heat penetration into the compartment and a thickness ratio of insulated walls in the refrigerator in accordance with the third exemplary embodiment of the present invention.

Fig. 10 is a plan sectional view of a basic structure of a storage compartment adjacent to a mechanical compartment in a refrigerator in accordance with a fourth exemplary embodiment of the present invention.

Fig. 11 is a magnified sectional view of a side part of an insulated door of the storage compartment adjacent to the mechanical compartment in the refrigerator in accordance with the fourth exemplary embodiment of the present invention.

Fig. 12 illustrates a relationship between an amount of heat penetration into the storage compartment and a thickness ratio of insulated walls in the refrigerator in the fourth exemplary embodiment of the present invention.

Fig. 13 is a vertical sectional view of a basic structure of a storage compartment adjacent to a mechanical compartment in a conventional refrigerator.

DESCRIPTION OF EMBODIMENTS

Exemplary embodiments of the present invention are described below with reference to drawings. Components same as the prior art or an exemplary embodiment already described are given same reference marks to omit their detailed description. It is apparent that the scope of the present invention is not limited to exemplary embodiments.

(FIRST EXEMPLARY EMBODIMENT)

Fig. 1 is a vertical sectional view of a refrigerator in the first exemplary embodiment of the present invention.

As shown in Fig. 1, refrigerator 100 includes insulated cabinet 101, insulated doors 117, 118, and 119; storage compartments 104, 105, and 106; insulated partitions 120 and 121; and mechanical compartment 107 housing compressor 108.

Insulated cabinet 101 includes outer cabinet 102 mainly using steel plate, and inner cabinet 103 made by molding resin such as ABS. Foam insulation such as rigid urethane foam is filled inside insulated cabinet 101 for thermal insulation from the surrounding. Multiple storage compartments 104, 105, and 106 are separated by insulated partitions 120 and 121. Front openings of storage compartments are covered with insulated doors 117, 118, and 119 that are rotatably supported by the main body of the refrigerator, respectively. For example, if storage compartments 104, 105, and 106 are used as a refrigeration compartment, a crisper, and a freezer compartment, respectively, refrigeration compartment 104 is set to the temperature for chilled storage not to freeze food, normally around 1 °C to 5 °C. Crisper 105 is set to the temperature equivalent to the refrigeration compartment or slightly higher at around 2 °C to 7 °C. Freezer compartment 106 is set to a freezing temperature zone. For frozen storage, this compartment is normally set to -22°C to -15°C, but for improving the frozen storage condition, it may also be set as low as to, for example, -30 °C to -25 °C. Mechanical compartment 107 is formed in an area back of the lowest storage compartment 106 in insulated cabinet 101. Mechanical compartment 107 houses components that configure a refrigerating cycle, including compressor 108 and a drier (not illustrated) for removing moisture.

Fig. 2 is a vertical sectional view of a basic structure of a storage compartment adjacent to the mechanical compartment of the refrigerator in the first exemplary embodiment of the present invention.

As shown in Fig. 2, cooling chamber 109 for producing cold air is provided at the back of storage compartment 106. Rear partition 110 is configured between storage compartment 106 and cooling chamber 109. Rear partition 110 has insulating properties, and insulates storage compartment 106 from cooling chamber 109. Cooler 111 is disposed inside cooling chamber 109. Cooling fan 112 is provided in a space above cooler 111 so as to feed cold air, which is cooled by a forced convection system in cooler 111, typically to storage compartments 104, 105, and 106 shown in Fig. 1. Radiant heater 113 made of glass tube is provided in a space below cooler 111 so as to defrost frost and ice attached to cooler 111 and its surrounding area while cooling. Drain pan 114 is provided in passage 115 below radiant heater 113 so as to receive and drain outside defrosted water generated during defrosting. Evaporation pan 116 is configured outside at downstream of passage 115.

Rear partition 110 has cold air outlet 124 and cold air inlet 125. Cooling fan 112 feeds the cold air produced in cooler 111 through cold air outlet 124 to storage compartment 106. Cold air inlet 125 is provided beneath cold air outlet 124. The cold air circulated in storage compartment 106 returns to cooler 111 through cold air inlet 125.

A storage case is provided in storage compartment 106. This storage case is typically held by a sliding mechanism, such as a rail, so that it can be drawn out. Food items are stored in the storage case. In this exemplary embodiment, three storage cases are provided in storage compartment 106. More specifically, they are upper storage case, middle storage case 127, and lower storage case 128.

Dimension a is a thickness of an insulated wall provided, between storage compartment 106 and mechanical compartment 107. Dimension a is also the thickness of the thickest portion in insulated walls surrounding mechanical compartment 107. Dimension a is also the thickness of the insulated wall where storage compartment 106 faces mechanical compartment 107 in a front-back direction. Still more, dimension a is the thickness of the insulated wall without passage 115 in the insulated walls surrounding storage compartment 106 and mechanical compartment 107. Furthermore, dimension a is the thickness of the insulated wall where storage compartment 106 faces mechanical compartment 107.

Dimension Z>is a thickness of insulated partition 121. Dimension b is detailed with reference to Fig. 3.

Fig. 3 is a magnified sectional view of an upper part of the insulated door of the storage compartment adjacent to the mechanical compartment in the refrigerator in the first exemplary embodiment of the present invention.

As shown in Fig. 3, door gasket 122 is provided on the entire periphery of an inner edge of insulated door 119 (same for storage compartment 104 and storage compartment 105). U-shaped metallic reciever 123 is provided across inside and outside of storage compartment 106 on the front face of insulated partition 121 whose outer periphery is formed of a resin part. Tight attachment of metallic reciever 123 and door gasket prevents the cold air from leaking outside. Metallic reciever 123 has U shape (a shape of II in Greek alphabets) that includes a horizontal part and vertical part. The horizontal part is appropriately supported by the front face of insulating partition 121, and the vertical part retains the close attachment with door gasket 122. This suppresses heat penetration into storage compartment 105 or storage compartment 106.

A heat-exchange suppressor is also provided between metallic reciever 123 and storage compartment 106. This further suppresses heat penetration.

More specifically, insulating material 130 is provided directly underneath metallic reciever 123. The horizontal part of metallic reciever 123 is positioned over insulating material 130 so that metallic reciever 123 is held by the front face of insulated partition 121 and insulating material 130. This enables suppression of the heat released from the horizontal part of metallic reciever 123 in an appropriate manner. This insulating material 130 is held by the resin part configuring the outer periphery of insulated partition 121.

Metallic reciever 123 has heat-releasing pipe 131 as a heater so as to prevent dew condensation on the outer face of storage compartment 106. Heat-releasing pipe 131 is provided such that it is closely attached to the side face of metallic reciever 123 inside the storage compartment. A high-temperature refrigerant pipe in a refrigerating cycle (not illustrated) is used for this heat-releasing pipe 131, and metallic reciever 123 is heated by that heat.

Next is described about dimension b. As described with reference to above Fig. 2, dimension Ms the thickness of insulated partition 121. Dimension bl is a height of metallic reciever 123 and a holder of metallic reciever 123. Dimension b2 is a height of insulating material 130 and. its holder. Dimension bl is fixed.

In this exemplary embodiment, for example, dimension b (=bl + b2) is set greater than dimension a in Fig. 2. More specifically, in this exemplary embodiment, dimension a, which is the thickness of insulated wall between storage compartment 106 and mechanical compartment 107, is 60 mmJ and dimension b, which is the thickness of insulated partition 121, is 70 mm (dimension bl is 49 mm and dimension b2 is 21 mm).
Now, a positional relationship between door gasket 122 and insulating material 130 is detailed. More specifically, door gasket 122 is disposed above the bottom face (position C in Fig. 3) of insulating material 130. This makes the cold air inside freezer compartment 106 less likely to flow toward door gasket 122, and a flow of cold air to door gasket 122, which is a component across inside and outside the compartment, can be reduced. Accordingly, heat exchange can be further suppressed.

Furthermore, the heat exchange between metallic reciever 123 and the cold air cools down metallic reciever 123. This can prevent dew condensation on a face of metallic reciever 123 exposed to outside the compartment due to an acute temperature difference between inside and outside that is greater than that of the prior art.

Next, a positional relationship between metallic reciever 123 and insulating material 130 is described.
Metallic reciever 123 heated by heat-releasing pipe 131 has lower flange 123a. More specifically, lower flange 123a is covered by insulating material 130, and a length relationship between a length of lower flange 123a (dimension A in Fig. 3) and a horizontal length of insulating material 130 (dimension B) is A < B. This relationship makes lower flange 123a, which becomes hot, covered with insulating material 130, and a temperature rise of the face exposed to cold air can be prevented. The heat exchange can thus be suppressed. The above structure suppresses warming of cold air and improves cooling efficiency. As a result, power consumption can be reduced.

The operation and effect of the refrigerator as configured above is described below with reference to Fig. 2.

First, a flow of cold air inside storage compartment 106 is described. The cold air cooled down by cooler 111 is forcibly blown from outlet 124 to upper, middle, and lower stages in storage compartment 106, as shown by arrow A, respectively, by cooling fan 112 that rotates in line with motor rotation. The cold air is blown toward storage cases 126, 127. and 128 to cool food items stored in them.

Next, the cold air after cooling food items passes between storage case 126 and insulated partition 121 in the upper stage, between storage case 126 and storage case 127 in the middle stage, and between storage case 127 and storage case 128 in the lower stage, as shown by arrow B, respectively. The cold air coming out from each of storage cases 126, 127, and 128 joins together between each storage cases 126, 127, and 128 and an inner wall of storage compartment 106. As shown by arrow C, joined cold air passes through a space between storage case 128 and a bottom wall of inner cabinet 103, and is drawn through inlet 125, as shown by arrow D, returning to cooler 111. At this point, the surface temperature
of compressor 108 becomes high due to thermal conduction from refrigerant that becomes high temperature by internal pressure rise, motor loss, mechanical loss, and so on. Due to this influence, the temperature of mechanical compartment 107 becomes about 10 °C higher in average than that of surrounding air.

As described above, the cold air becomes warm by heat exchange with the surface inside each storage compartment while the cold air circulates in storage compartment 106. Accordingly, power can be saved if heat penetration is reduced so as to prevent the surface temperature rise inside storage compartment.

Next, heat penetration is described.

In general, heat penetration Q (W) is expressed by the following formula.

Q = K*A * AT
K = l/(l/ao + L / X + 17 αi)

Here, K is heat passage rate (W/m2K), A is heat passage area (m2), AT is temperature difference between inside and outside the storage compartment, ao is convention heat transfer rate outside the storage compartment (W/m2K), ai is convection heat transfer rate inside the storage compartment (W/m2K), L is insulating distance (m), and X is thermal, conductivity of insulated portion (W/mK). It is apparent from this Formula that heat penetration Q can be reduced by increasing insulating distance L.

In particular, the heat enters through the opening due to external air penetrating inside storage compartment 106 by thermal conduction of metallic reciever 123. However, a temperature of metallic reciever 123 up to a portion reaching inside storage compartment 106 becomes almost the same as that of external air. This means that contribution of insulating distance L, i.e., dimension b2in Fig. 3, is extremely high. (An item of ao is ignored here.) If there is no insulating material 130, as in the prior art, and dimension b2 is only the thickness of resin part that configures the outer periphery of insulated partition 121, it is obvious that an amount of heat penetration becomes extremely high.

Next, a relationship between the amount of heat penetration and the thickness of insulated wall is described.

Fig. 4 illustrates a general relationship between the amount of heat penetration and the thickness of insulated wall. Fig. 5 illustrates a relationship between the amount of heat penetration into the storage compartment and a thickness ratio of insulated walls (dimension b divided by dimension a) in the refrigerator in the first exemplary embodiment. Area I shows an area of dimension a < dimension b.
As shown in Fig. 5, if dimension b (dimension b2) is increased, which means that insulated wall thickness (m) of insulated partition 121 is increased, amount of penetration heat (W) reduces. However, after reaching the lowest point at a certain value, the amount of heat penetration starts to increase again. This is because that this relationship is established on the premise that the outer dimensions of the refrigerator and the storage capacity are retained in an appropriate manner when a volume efficiency that indicates a percentage of volume of storage space against the outer volume of the refrigerator is between 30%
and 70%. Accordingly, if the insulated wall thickness on one side is increased, the insulated wall thickness on the other side is decreased. In other words, as shown in Fig. 4, after exceeding a certain thickness ratio of insulated walls, the relationship between amount of heat penetration AQ2 from the opening that can be reduced by increasing dimension b2 and amount of heat penetration AQl through insulated walls that increases by decreasing dimension a becomes AQl > AQ2. Therefore, the thickness ratio of insulated walls that minimizes the amount of heat penetration exists on the premise that the outer dimensions of the refrigerator and the storage capacity are kept the same. At this ratio, dimension a < dimension b is achieved.

Accordingly, as in this exemplary embodiment, heat penetration through insulated walls and heat penetration from the opening can be comprehensively reduced by setting dimension b that is the thickness of insulated partition 121 greater than dimension a that is the thickness of insulated wall provided between storage compartment 106 and mechanical compartment 107.

Still more, reduced heat penetration enables prevention of surface temperature rise inside the storage compartment. Accordingly, the cold air keeps low temperature during circulation. The temperature distribution in entire storage compartment 106 can thus be uniformly retained.

Furthermore, the thickness of insulated partition 121 does not necessarily be constant relative to the depth direction of storage compartment 106. In other words, a thickness of insulated partition 121
only around a portion that makes contact with metallic reciever 123 near the opening is made thicker than dimension a, and other portion may be thinned. This can also achieve the same effect.

Dimensions of insulated wall thicknesses described in this exemplary embodiment are just given as examples, and thus the present invention is not limited to these dimensions.

(SECOND EXEMPLARY EMBODIMENT)
Fig. 6 is a magnified sectional view of an upper part of an insulated door of a storage compartment adjacent to a mechanical compartment of a refrigerator in the second exemplary embodiment of the present invention. In Fig. 6, a point that differs from the first exemplary embodiment is that protrusion 150 is provided on a face of partition 122 in contact with storage compartment 106. Protrusion 150 makes contact with storage case 126 for an upper stage of storage compartment 106.

The operation and effect of the refrigerator as configured above are described below. Description of the operation and effect same as that of the first exemplary embodiment is omitted.

For example, a flow of cold air toward metallic reciever 123 warmed by heat-releasing pipe 131 is blocked by providing protrusion 150 on a wall face of partition 122 in contact with freezer 106 and making this protrusion 150 contact with storage case 126 when the cold air is blown through outlet 124 and circulates in freezer 106. This enables suppression of heat exchange between metallic reciever 123 and the cold
air without increasing costs due to additional components and assembly man hours. Cooling efficiency thus improves, and as a result, power consumption can be reduced.

The cold air may leak toward metallic reciever 123 due to storage case 126 not making contact with protrusion 150 of the wall face of partition 122 in contact with freezer 106, typically due to deformation of storage case 126 by aged degradation. Also in this case, heat movement from heat-releasing pipe 131 to the face exposed to the cold air is reduced by providing insulating material 130 directly beneath metallic reciever 123. Temperature rise of the face exposed cold air is thus prevented, suppressing heat exchange.

Still more, since the cold air keeps low temperature during circulation by suppressing warming of the cold air, the temperature distribution in entire freezer compartmentl06 can be uniformly retained.

Furthermore, heat exchange between metallic reciever 123 and the cold air cools down metallic reciever 123. This prevents dew condensation on a face of metallic reciever 123 exposed to outside the compartment due to an acute temperature difference between inside and outside that is greater than that of the prior art.

As described above, a heat-exchange suppressor in this exemplary embodiment has a structure that the protrusion is provided on the bottom face of the partition and this protrusion makes contact with the storage case. Accordingly, the protrusion provided on the partition and the storage case seal the compartment. The flow of cold air toward heated metallic reciever thus reduces. A simple structure offers a refrigerator that can suppress warming of the cold air, improve cooling efficiency, and reduce power consumption. In addition, by providing the insulating material directly underneath the metallic reciever, heat movement from the heat-releasing pipe to the face exposed to cold air is reduced, even if the cold air leaks toward metallic reciever, because the cold air passes through the insulating material with low thermal conductivity. The temperature rise of the face exposed to cold air is prevented, and heat exchange is suppressed. Accordingly, warming of the cold air can be further suppressed to improve the cooling efficiency. As a result, power consumption can be further reduced.

Insulating material 130 is provided directly underneath metallic reciever 123 in this exemplary embodiment. However, insulating material 130 may not be provided.

In this exemplary embodiment, protrusion 150 is integrally configured with partition 122. However, a separate configuration is also applicable.

THIRD EXEMPLARY EMBODIMENT

Fig. 7 is a vertical sectional view of a basic structure of a storage compartment adjacent to a mechanical compartment in a refrigerator in the third exemplary embodiment of the present invention. Fig. 8 is a magnified sectional view of a lower part of an insulated door of the storage compartment adjacent to the mechanical compartment in the refrigerator in the third exemplary embodiment of the present invention.

Same reference marks are given to components same as that of the first exemplary embodiment to omit their detailed description.

As shown in Fig. 7, dimension c is a an insulated wall thickness of bottom insulated wall 133 of storage compartment 106. As shown in Fig. 8, metallic reciever 131 is provided on the front of bottom insulated wall 133 across inside and outside the storage compartment. Door gasket 122 is provided at an edge of an inner face of insulated door 119. Metallic reciever 131 is closely attached to door gasket 122 so as to prevent the cold air from leaking outside.

A folded flange of metallic reciever 131 is embedded inside bottom insulated wall 133.

Dimension cl is a height from the bottom face of outer cabinet 102 to a folded tip of metallic reciever 131, and dimension c2is a height from the folded flange tip of metallic reciever 131 to storage compartment 106, i.e., an insulating distance. Dimension cl is fixed.

In this exemplary embodiment, dimension b (= bl + b2) and also dimension c (= cl + c2) are set greater than dimension a typically shown in Fig. 2. More specifically, in this exemplary embodiment, dimension a, which is the thickness of the insulated wall between storage compartment 106 and mechanical compartment 107, is 60 mm! dimension b, which is the thickness of insulated partition 121, is 70 mm (dimension bl is 49 mm and dimension b2is 21 mm); and dimension c, which is the thickness of bottom insulated wall 133, is 71 mm (dimension cl is 41 mm and dimension c2is 30 mm).

The operation and effect of the refrigerator as configured above is described below. Description of operation and effect that are same as that of the first exemplary embodiment is omitted.

External air penetrates into storage compartment 106 by thermal conduction of metallic reciever 131, and a temperature of metallic reciever 131 up to the folded flange tip becomes almost the same as that of external air. The insulating distance, i.e., dimension c2in Fig. 8, thus highly contributes to insulation. In the prior art, the thickness of bottom insulated wall 133 is set based only on the temperature difference between inside and outside the storage compartment, and thus dimension c2is small. In other words, the insulating distance is small. It is obvious that an amount of heat penetration becomes extremely high.

Fig. 9 illustrates a relationship between an amount of heat penetration into the storage compartment in the refrigerator and a thickness ratio of insulated walls (an average of dimension band dimension c divided by dimension a). Area I is an area where dimension a < dimension b and dimension a < dimension c are achieved.

As shown in Fig. 9, the amount of heat penetration reduces as the thickness ratio of insulated walls increases, but the amount of heat penetration starts to increase again after reaching the lowest point at a certain value. In other words, when a volume efficiency that indicates a percentage of volume of storage space against the outer volume of the refrigerator is 30 % to 70%, the thickness ratio of insulated walls that minimizes the amount of heat penetration exists on the premise that the outer dimensions of the refrigerator and the storage capacity are retained in an appropriate manner. At this ratio, dimension a < dimension b and dimension a < dimension c are achieved.

Accordingly, as in this exemplary embodiment, dimension b, which is the thickness of insulated partition 121, is set greater than dimension a; which is the thickness of insulated wall between storage compartment 106 and mechanical compartment 107i and also dimension c, which is the thickness of bottom insulated wall 133, is set greater than dimension a, which is the thickness of insulated wall between storage compartment 106 and mechanical compartment 107. This comprehensively reduces the heat penetration through the insulated walls and the heat penetration from the opening.

Still more, a surface temperature rise inside storage compartment can be prevented by reducing heat penetration. The cold air thus keeps low temperature during circulation. A temperature distribution in entire storage compartment 106 can be uniformly retained.

The thickness of insulated partition 121 does not necessarily be constant relative to the depth direction of storage compartment 106. More specifically, for example, a thickness of insulated partition 121 only around a portion that makes contact with metallic reciever 123 around the opening is made thicker than dimension a shown in Fig. 2, and other portion may be thinned. This also achieves the same effect.
Dimensions of insulated wall thicknesses indicated in this exemplary embodiment are just given as examples, and thus the present invention is not limited to these dimensions.

FOURTH EXEMPLARY EMBODIMENT
Fig. 10 is a plan sectional view of a basic structure of a storage compartment adjacent to a mechanical compartment of a refrigerator in the fourth exemplary embodiment of the present invention. Fig. 11 is a magnified sectional view of a side part of an insulated door of the storage compartment adjacent to the mechanical compartment in the refrigerator in the fourth exemplary embodiment. Same reference marks are given to components same as that of the first exemplary embodiment to omit their detailed description.

As shown in Fig. 10, dimension dis an insulated wall thickness of side insulated wall 134 of storage compartment 106. As shown in Fig. 11, metallic reciever 132 is provided on the front of side insulated wall 134 across inside and outside of the storage compartment. Door gasket 122 is provided at an edge of an inner face of outer cabinet 102. Metallic reciever 132 is integrally provided with outer cabinet 102 and closely attached to door gasket 122 so as to prevent the cold air from leaking outside.
A folded flange of metallic reciever 132 is embedded inside side insulated wall 134.

Dimension dl is a width dimension from the side face of outer cabinet 102 to a folded flange tip of metallic reciever 132. Dimension d2 is a width dimension from the folded flange tip of metallic reciever 132 to storage compartment 106, i.e., an insulating distance. Dimension dl is fixed.

In this exemplary embodiment, dimension b {-bl + b2) is set greater than dimension a typically shown in Fig. % dimension c (=cl + c2) is also set greater than dimension a typically shown in Fig. 2; and dimension d(=dl + d2) of an insulated wall thickness of side insulated wall 134 is also set greater than dimension a typically shown in Fig. 2. More specifically, in this exemplary embodiment, dimension a, which is the thickness of the insulated wall between storage compartment 106 and mechanical compartment 107, is 60 mm; dimension b, which is the thickness of insulated partition 121, is 70 mm (dimension bl is 49 mm and dimension b2 is 21 mm); dimension c, which is the thickness of bottom insulated wall 133, is 71 mm (dimension clis 41 mm and dimension c2is 30 mm); and dimension d, which is the thickness of side insulated wall 134, is 65 mm (dimension dl is 20 mm and dimension d2 is 45 mm).

The operation and effect of the refrigerator as configured above is described below. Description of the operation and effect that are same as that of the first or second exemplary embodiment is omitted.

External air penetrates into storage compartment 106 by thermal conduction of metallic reciever 132, and a temperature of metallic reciever 132 up to the folded flange tip becomes almost the same as that of external air. The insulating distance, i.e., dimension d2in. Fig. 11, thus highly contributes to insulation. In the prior art, the thickness of side insulated wall 134 is set based only on the temperature difference between inside and outside the storage compartment, and thus dimension d2is small. In other words, the insulating distance is small. It is obvious that an amount of heat penetration becomes extremely high.

Fig. 12 illustrates a relationship between the amount of heat penetration into the storage compartment of refrigerator in the fourth exemplary embodiment of the present invention and a thickness ratio of insulated walls (an average of dimension b, dimension c, and dimension d divided by dimension a). Area I is an area where dimension a < dimension b, dimension a < dimension c, and dimension a < dimension d are achieved.

As shown in Fig. 12, the amount of heat penetration reduces as the thickness ratio of insulated walls increases, but the amount of heat penetration starts to increase again after reaching the lowest point at a certain value. In other words, when a volume efficiency that indicates a percentage of volume of storage space against the outer volume is 30% to 70%, the thickness ratio of insulated walls that minimizes the amount of heat penetration exists on the premise that the outer dimensions of refrigerator and the storage capacity are retained in an appropriate manner. At this ratio, dimension a < dimension b, dimension a < dimension c, and dimension a < dimension d are achieved.

Accordingly, as in this exemplary embodiment, dimension b, which is the thickness of insulated partition 121, is set greater than dimension a, which is the thickness of the insulated wall provided between storage compartment 106 and mechanical compartment 107. Dimension c, which is the thickness of bottom insulated wall 133, is also greater than dimension a, which is the thickness of the insulated wall provided between storage compartment 106 and mechanical compartment 107. Dimension d, which is the thickness of side insulated wall 134, is also set greater than dimension a, which is the thickness of the insulated wall provided between storage compartment 106 and mechanical compartment 107. This comprehensive reduces the heat penetration through the insulated walls and the heat penetration from the opening.

Still more, a surface temperature rise inside storage compartment can be prevented by reducing heat penetration. The cold air thus keeps low temperature during circulation. A temperature distribution in entire storage compartment 106 can be uniformly retained.

The thickness of side insulated wall 134 does not necessarily be constant relative to the depth direction of storage compartment 106. More specifically, for example, a thickness of side insulated wall 134 only around a portion that makes contact with metallic reciever 132 around the opening is made thicker than dimension a shown in Fig. 2. This also achieves the same effect.

Dimensions of insulated wall thicknesses in this exemplary embodiment are just given as examples, and thus the present invention is not limited to these dimensions.

INDUSTRIAL APPLICABILITY

The refrigerator of the present invention is effectively applicable to household or industrial-use refrigerators and vegetable refrigerators.

REFERENCE MARKS IN THE DRAWINGS

100 Refrigerator
101 Insulated cabinet
102 Outer cabinet
103 Inner cabinet
104 Storage compartment (refrigeration compartment)
105 Storage compartment (crisper)
106 Storage compartment (freezer)
107 Mechanical compartment
108 Compressor
109 Cooling chamber
110 Rear partition
111 Cooler
112 Cooling fan
113 Radiant heater
114 Drain pan
115 Passage
117, 118, 119 Insulated door
120, 1212 Insulated partition
122 Door gasket
123, 132 Metallic reciever
124 Cold air outlet
125 Cold air inlet
126, 127, 128 Storage case
130 Insulating material
131 Heat-releasing pipe
133 Bottom insulated wall
134 Side insulated wall
150 Protrusion

CLAIMS

1. A refrigerator comprising:

an insulated cabinet;

an insulated door for opening and closing a front face of an opening of the insulated cabinet;

a storage compartment including the insulated cabinet and the insulated door;

an insulated partition for dividing the storage compartment into a plurality of storage compartments; and
a mechanical compartment for housing a compressor, the mechanical compartment provided at a lower part of the insulated cabinet,

wherein
a thickness of the insulated partition is greater than a thickness of an insulated wall provided between the storage compartment and the mechanical compartment.

2. The refrigerator of claim 1,
wherein

the thickness of the insulated wall provided between the storage compartment and the mechanical compartment represents a greatest thickness in a part of insulated walls surrounding the mechanical compartment.

wherein
the insulated wall provided between the storage compartment and the mechanical compartment is an insulated wall facing the mechanical compartment in a front-back direction.

4. The refrigerator of claim 1,
wherein

the insulated wall provided between the storage compartment and the mechanical compartment is an insulated wall without a passage in insulated walls surrounding the mechanical compartment.

5. The refrigerator of claim 1,
wherein

the insulated wall provided between the storage compartment and the mechanical compartment is an insulated wall of the mechanical compartment facing the interior of the storage compartment.

6. The refrigerator of one of claims 1 to 5,
wherein

a thickness of a bottom insulated wall forming the storage compartment is greater than the thickness of the insulated wall provided between the storage compartment and the mechanical compartment.

7. The refrigerator of one of claims 1 to 5,
wherein

a thickness of a side insulated wall forming the storage compartment is greater than the thickness of the insulated wall provided between the storage compartment and the mechanical compartment.

8. The refrigerator of claim 1, further comprising:

a metallic receiver provided on a front face of the insulated partition; and

a heater disposed such that it closely attaches to a face of the metallic receiver at a side of the storage compartment,

wherein

a heat-exchange suppressor is provided between the metallic receiver and the storage compartment for suppressing heat exchange between cool air inside the storage compartment and the metallic receiver.

9. The refrigerator of one of claims 1 to 8, wherein the storage compartment is a freezer compartment.

10. The refrigerator of one of claims 1 to 8, wherein the storage compartment has a slidable storage case.

11. The refrigerator of claim 8, wherein a thickness of the insulated partition only around a portion in contact with the metallic receiver is greater than the thickness of the insulated wall provided between the storage compartment and the mechanical compartment, and

a thickness of other portion of the insulated partition is smaller than the thickness of the insulated wall.

12. The refrigerator of claim 8, wherein the heat-exchange suppressor is configured by providing an insulating material between the metallic receiver and the storage compartment.

13. The refrigerator of claim 8, wherein the heat-exchange suppressor is configured by providing a protrusion on a bottom face of the insulated partition and making the protrusion in contact with the storage case.