The present invention relates to refrigerators, and relates particularly to a refrigerator including a defrosting heater that removes frost formed on a cooler.

A refrigerator includes a cooler for cooling an inside of the refrigerator. Frost is formed on the cooler when moisture in the air is formed into frost during a process of cooling the air around the refrigerator. Then, an increase in amount of the frost on the cooler reduces conduction from a surface of the cooler to the air with which the cooler exchanges heat and also decreases the amount of cool air passing through the cooler, thus resulting in insufficient cooling. Accordingly, to regularly remove the frost formed on the cooler, the cooler includes a defrosting heater for defrosting.

In addition, in recent years, in response to environmental problems such as ozone depletion or global warming due to CFCs, a hydrocarbon system refrigerant (hereinafter, referred to as HC refrigerant) is used as a refrigerant for the cooler. However, the HC refrigerant, which is flammable, has a possibility of being ignited by the defrosting heater in case of outside leakage of the HC refrigerant.

For this reason, a refrigerator which is conventionally suggested is intended to prevent ignition by providing a pipe heater, as a defrosting pipe heater, in a lower part of the cooler, in contact with the cooler so as to decrease a surface temperature of the pipe heater (For example, see Patent Reference 1). This allows defrosting, by the pipe heater, a lower part of the cooler on which a large amount of frost is formed.

In addition, another suggested refrigerator is intended to prevent ignition by providing, in a lower part of the cooler, a sheathed heater having no risk of breakage. With this, a radiant heat from the sheathed heater removes the frost in the lower part of the cooler on which a large amount of frost is formed.

• Patent Reference 1: Japanese Unexamined Patent Application Publication No. 2002-372363.
• Patent Reference 2: Japanese Unexamined Patent Application Publication No. 2003-139463.
• Patent Reference 3: EP patent application 1 369 650

However, a conventional refrigerator has a problem that the defrosting heater can defrost the lower part of the cooler but may fail to defrost an upper part of the cooler.

A failure in defrosting the entire cooler results in insufficient cooling. For this reason, the defrosting heater needs to defrost not only the lower part but also the upper part of the cooler. Then, to defrost the upper part of the cooler as well, it is necessary to cause the defrosting heater to generate a larger amount of heat. However, the temperature of the defrosting heater, when raised too high, has a possibility of the HC refrigerant being ignited in case of leakage of the HC refrigerant. Accordingly, the conventional refrigerator has a problem of not being able to raise the temperature of the defrosting heater and thus having a possibility of failing to defrost the upper part of the cooler.

From Patent Reference 3, a refrigerator can be inferred which includes a heat-insulating main body having an opening in a front face, and a cooler for cooling air inside that heat-insulating main body. That known refrigerator comprises two radiant heater for removing frost formed on that cooler by radiant heat one of which is provided below that cooler and the other of which is provided in an upper part of that cooler.

Thus, an object of the present invention which is conceived in view of such a problem is to provide a refrigerator which defrosts the entire cooler without raising the temperature of the defrosting heater too high.

To achieve the above object, a refrigerator according to the present invention is a refrigerator which includes a heat-insulating main body having an opening in a front face, and a cooler for cooling air inside the heat-insulating main body, and the refrigerator includes: a radiant heater which is provided below the cooler and removes frost formed on the cooler by radiant heat; and a contact heater which is provided in an upper part of the cooler and removes the frost formed on the cooler by thermal conduction.

With this, the lower part of the cooler is defrosted by the radiant heat from the radiant heater, and the upper part of the cooler is defrosted by thermal conduction from the contact heater. This allows defrosting the entire cooler without raising the temperature of the defrosting heater too high.

In addition, the refrigerator further includes a pair of reflective plates between which the cooler is placed, with one plate of the pair in front and the other plate of the pair behind the cooler.

With this, the cooler is placed between a pair of reflective plates, with one of the pair in front and the other behind the cooler. Thus, the reflective plates allow the radiant heat from the radiant heater to heat the frosted portion of the cooler without dissipation of the radiant heat, thus efficiently allowing defrosting. Accordingly, this allows defrosting the entire cooler without raising the temperature of the defrosting heater too high.

In addition, at least one plate of the pair of reflective plates includes a groove, the groove extending in a vertical direction, opening at a bottom end portion, and being outwardly recessed from the cooler.

Preferably, each of the reflective plates includes a groove. This allows the groove to function as an air path for cool air even when frost formation causes a clog in the lower part of the cooler, thus making it possible to blow the cool air. Accordingly, this allows defrosting the entire cooler without raising the temperature of the defrosting heater too high, along with keeping the air path for the cool air when frost is formed.

In addition, it is preferable that the refrigerator further include a holding member provided between an inner lateral wall of the heat-insulating main body and a lateral side of the cooler, and fixed to the heat-insulating main body, to hold the cooler. In addition, it is preferable that the refrigerator further include a cover covering a front of the cooler and attached to an inner wall of the heat-insulating main body via the holding member.

With this, the holding member that holds the cooler is placed on a lateral side of the cooler, and the cover is attached to the holding member. Thus, since it is not necessary to attach the cover to the heat-insulating main body, it is not necessary to provide, in the heat-insulating main body, a space for attachment of the cover. This accordingly allows placement of the cooler in the space of the heat-insulating main body, thus allowing increasing a width of the cooler.

Since the present invention allows providing a refrigerator which defrosts the entire cooler without raising the temperature of the defrosting heater too high, the practical value of the present invention is extremely high.

• [FIG. 1] FIG. 1 is a perspective view showing an external appearance of a refrigerator.
• [FIG. 2] FIG. 2 is a perspective view showing an external appearance of a refrigerator from which a first door and a second door are omitted.
• [FIG. 3] FIG. 3 is a cross-sectional view schematically showing a cross section of a second storage compartment.
• [FIG. 4] FIG. 4 is a perspective view showing an external appearance of a cooling unit provided behind the second storage compartment.
• [FIG. 5] FIG. 5 is a diagram showing a configuration of the cooling unit.
• [FIG. 6] FIG. 6 is a diagram schematically showing the configuration of a cooler.
• [FIG. 7] FIG. 7 is a diagram for describing defrosting by a radiant heater.
• [FIG. 8] FIG. 8 is a diagram for describing defrosting by a contact heater.
• [FIG. 9] FIG. 9 is a diagram for describing defrosting by a contact heater.
• [FIG. 10A] FIG. 10A is a diagram for describing a configuration and a function of reflective plates.
• [FIG. 10B] FIG. 10B is a diagram for describing a configuration and a function of the reflective plates.
• [FIG. 11] FIG. 11 is a diagram for describing a layout and configuration of a holding member.
• [FIG. 12] FIG. 12 is a diagram for describing a layout and a configuration of the holding member.
• [FIG. 13] FIG. 13 is a diagram for describing a layout and a configuration of a cover.
• [FIG. 14] FIG. 14 is a diagram for describing a layout and a configuration of the cover.
• [FIG. 15A] FIG. 15A is a diagram for describing an advantageous effect produced by providing the holding member.
• [FIG. 15B] FIG. 15B is a diagram for describing an advantageous effect produced by providing the holding member.
• [FIG. 16] FIG. 16 is a diagram showing a variation of the present embodiment, in which a front plate and a rear plate have lengths different from each other.

100

Refrigerator

111

First door

112

Third door

113

Through hole

121

Second door

122

Fourth door

123

Opening

150

Heat-insulating main body

151

First storage compartment

152

Second storage compartment

153

Partition

154

Back face

300

Cooling unit

310

Cooler

311

Cooling pipe

312

Radiant heater

313

Contact heater

320

Reflective plates

321

Front plate

321a

Groove

322

Rear plate

322a

Groove

330

Holding member

331

Projection

332

Holding member hole

340

Cover

340a

Cover recessed portion

341

Fan

342

Cover hole

400

Inner case

400a

Inner-case recessed portion

Hereinafter, an embodiment of a refrigerator according to the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view showing an external appearance of a refrigerator.

As shown in the figure, the refrigerator 100 includes: a heat-insulating main body 150, a first door 111, a second door 121, a third door 112, a through hole 113, a fourth door 122, and an opening 123.

The heat-insulating main body 150 is a box-shaped body having an opening in a front face, and has heat insulation properties that shut off heat coming in and out of the refrigerator 100.

The first door 111 is a door which covers, to allow opening and closing, an opening provided on the right with respect to the heat-insulating main body 150. In the present embodiment, the first door 111 is attached to the heat-insulating main body 150 using a hinge (not shown) so as to rotate centering on an axis that vertically extends at a position in front of a right wall of the heat-insulating main body 150. In addition, the first door 111 is rectangular in shape as viewed from the front, with an axis passing through a right-end rim portion of the first door 111.

The second door 121 is a door which covers, to allow opening and closing, an opening provided on the left with respect to the heat-insulating main body 150. In the present embodiment, the second door 121 is attached to the heat-insulating main body 150 using a hinge (not shown) so as to rotate centering on an axis that vertically extends at a point in front of a left wall of the heat-insulating main body 150. In addition, the second door 121 is rectangular in shape as viewed from the front, with an axis passing through a left-end rim portion of the second door 121.

The through hole 113 is a hole penetrating through the first door 111 in a thickness direction. The through hole 113 is a hole through which to take out a storage item that is stored behind the first door 111 and to put in an item for storage behind the first door 111, without opening the first door 111.

The third door 112 is a door that covers the through hole 113 to allow opening and closing. In the present embodiment, the third door 112 is attached to the first door 111 using a hinge (not shown) so as to rotate centering on an axis that horizontally extends along a lower end rim of the through hole 113. In addition, the third door 112 is square in shape as viewed from the front (round-cornered), with an axis passing through a lower-end rim portion of the third door 112.

The fourth door 122 is a door that covers, to allow opening and closing, the opening 123 for receiving ice that is supplied from inside of the refrigerator.

FIG. 2 is a perspective view showing an external appearance of a refrigerator from which the first door and the second door are omitted.

As shown in the figure, the refrigerator 100 includes a partition 153 and a drawer 162.

The partition 153 is a wall partitioning an inside of the heat-insulating main body 150 into right and left. In the present embodiment, in the heat-insulating main body 150, a portion located on the right side of the partition 153 is a first storage compartment 151 which is a refrigerator compartment. On the other hand, in the heat-insulating main body 150, a portion located on the left side of the partition 153 is a second storage compartment 152 which is a freezer compartment. The partition 153 is a wall partitioning the refrigerator compartment from the freezer compartment, and has heat insulation properties.

The drawer 162 is a container which is provided inside the heat-insulating main body 150 and opens upward, and allows pulling in an anterior direction and inserting in a posterior direction. In the present embodiment, three drawers 162 are provided in each of the first storage compartment 151 and the second storage compartment 152.

Behind a lower part of the back faces of the first storage compartment 151 and the second storage compartment 152 (behind the drawer 162), a cooler for cooling an inside of each of the first storage compartment 151 and the second storage compartment 152 is provided. Specifically, behind the lower part of a back face 154 (portion A shown in the figure) of the second storage compartment 152, a cooler for generating cool air for cooling the inside of the second storage compartment 152 is provided.

Here, since the second storage compartment 152 is the freezer compartment, it is necessary to keep the cooler provided behind the second storage compartment 152 at a low temperature. As a result, the cooler located behind the second storage compartment 152 is more likely to collect frost, thus needs regular defrosting. The following describes details of the configuration of the cooler provided behind the second storage compartment 152 and the configuration thereof for defrosting.

FIG. 3 is a cross-sectional view schematically showing a cross section of the second storage compartment 152.

FIG. 4 is a perspective view showing an external appearance of the cooling unit 300 provided behind the second storage compartment 152.

As shown in FIGS. 3 and 4, behind the lower part of the back face 154 of the second storage compartment 152, the cooling unit 300 for cooling the inside of the second storage compartment 152 is provided. Specifically, the cooling unit 300 is fixed to an inner case 400 which forms an inner wall of the heat-insulating main body 150 behind a lower part of the second storage compartment 152. The cooling unit 300 is an apparatus which cools the air introduced from inside of the second storage compartment 152 and derives the cooled air to the second storage compartment 152.

Specifically, the cooling unit 300 generates the cool air, through the cooler 310 included inside the cooling unit 300. Then, the cooling unit 300 blows, using a fan 341, the generated cool air upward along an air path W, to blow the cool air into the second storage compartment 152.

In addition, in the cooling unit 300, the cooler 310 is thermally insulated from a front of an inner wall of the second storage compartment 152 by an insulation material provided in a rear side of the back face 154 so that the inside of the second storage compartment 152 is not directly cooled by the cooler 310.

FIG. 5 is a diagram showing a configuration of the cooling unit 300.

As shown in the figure, the cooling unit 300 includes: the cooler 310, reflective plates 320, a holding member 330, and a cover 340.

The cooler 310 is an apparatus for cooling the air around the cooler 310 provided inside the heat-insulating main body 150. The detailed description of the cooler 310 will be described later.

The reflective plates 320 are sheet-like aluminum plates for containing heat for removing the frost formed on the cooler 310. Specifically, the reflective plates 320 include a pair of a front plate 321 and a rear plate 322. Then, the cooler 310 is placed between the front plate 321 and the rear plate 322, with one of the plates in front and the other behind the cooler. In addition, a cover recessed portion 340a that is a portion recessed toward a storage compartment side is included in the cover 340 corresponding to the front plate 321, and an inner-case recessed portion 400a is included in the inner case 400 corresponding to the rear plate 322.

The holding member 330 is a member for holding the cooler 310. Specifically, the holding member 330 is a pair of sheet-like members provided on both sides of the cooler 310 and extending in a vertical direction. Then, the holding member 330 is provided between an inner lateral wall of the heat-insulating main body 150 and a lateral side of the cooler 310, and is fixed to the heat-insulating main body 150, to hold the cooler 310.

The cover 340 is a cover that covers a front of the cooler 310. The cover 340 is attached to an inner wall of the heat-insulating main body 150 via the holding member 330. In addition, the cover 340 includes the fan 341 that blows upward the cool air generated by the cooler 310.

FIG. 6 is a diagram schematically showing the configuration of the cooler 310.

As shown in the figure, the cooler 310 includes a cooling pipe 311, a radiant heater 312, and a contact heater 313.

The HC refrigerant which is a cooled refrigerant flows inside the cooling pipe 311, to cool the air around the cooling pipe 311. Here, during this cooling, moisture in the air around the cooling pipe 311 is formed into frost, to attach to the cooling pipe 311.

The radiant heater 312 is provided below the cooler 310, and removes the frost formed on the cooler 310 mainly by radiant heat. In other words, the radiant heater 312 removes the frost formed on the lower part of the cooling pipe 310. The radiant heater 312 is, for example, a glass tube heater or a sheathed heater.

The contact heater 313 is provided in an upper part of the cooler 310 and removes the frost formed on the cooler 310 mainly by thermal conduction. In other words, the radiant heater 313 removes the frost formed on the upper part of the cooler 310. The contact heater 313 is, for example, a pipe heater.

FIG. 7 is a diagram for describing the defrosting by the radiant heater 312. Note that the figure shows a diagram of the lower part of the cooler 310 shown in FIG. 6 as viewed from the left.

As shown in the figure, the radiant heater 312 is a cylindrical heater and provided below the cooler 310. In addition, the radiant heater 312 generates radiant heat. Then, the radiant heat generated from the radiant heater 312 serially removes frost, starting with the frost formed at the bottom toward the upper part of the cooler 310.

Thus, the radiant heater 312 removes the frost formed on the lower part of the cooler 310 by radiant heat.

FIGS. 8 and 9 are diagrams for describing the defrosting by the contact heater 313. Note that FIG. 8 is a diagram of a top portion of the cooler 310 shown in FIG. 6 as viewed from the left, and FIG. 9 is a perspective view of the cooler 310 shown in FIG. 8 as viewed from diagonally right above.

As shown in FIGS. 8 and 9, the contact heater 313 is a pipe-shaped heater and is provided in front and rear faces of the upper part of the cooler 310, in contact with the cooling unit 310. In addition, the contact heater 313 is heated to generated heat. In addition, the heat generated by the contact heater 313 is transmitted to the cooler 310 that is provided in contact with the contact heater 313, and heats an upper surface of the cooler 310, thus removing the frost formed on the upper surface of the cooler 310. In addition, the heat, having heated the upper surface of the cooler 310, is also transmitted to an inside of the cooler 310, so that the frost formed inside the cooler 310 is also removed.

Thus, the contact heater 313 removes the frost formed on the upper part of the cooler 310 by thermal conduction.

Next, the configuration and function of the reflective plate 320 will be described in detail.

FIGS. 10A and 10B are diagram for describing the configuration and function of the reflective plate 320. Note that FIG. 10A shows a positional relationship between the cooler 310 and the reflective plate 320, and FIG. 10B is a cross-sectional view of a portion cut along line B-B in FIG. 10A.

As shown in FIG. 10A, the cooler 310 is placed between the reflective plates 320, with one of the plates in front and the other behind the cooler 310. In other words, the front plate 321 is placed in front of the cooler 310, and the rear plate 322 is placed in the rear of the cooler 310. In addition, the front plate 321 and the rear plate 322 are placed below the contact heater 313.

Note that a vertical length of each of the front plate 321 and the rear plate 322 is 1/2 H where H is a length of a vertical direction of the cooler 310. In other words, the front plate 321 and the rear plate 322 have a vertical length that is half the vertical length of the cooler 310.

Thus, the front plate 321 and the rear plate 322 allow the radiant heat from the radiant heater 312 to heat the frosted portion of the cooler 310 without dissipating the radiant heat to the outside, thus allowing efficient defrosting.

In addition, the front plate 321 and the rear plate 322 include, respectively, a groove 321a and a groove 322a each of which extends in a vertical direction and opens at a lower end portion. Note that the figure only illustrates the groove 322a while omitting the groove 321a, but the groove 321a has the same structure as the groove 322a.

In addition, as shown in FIG. 10B, the groove 321a and groove 322a are grooves that are outwardly recessed from the cooler 310.

Thus, even when frost is formed to cause a clog in the lower part of the cooler, the groove functions as an air path for cool air, thus allowing blowing the cool air. Specifically, as shown in FIG. 10A, the grooves 321a and 322a form air paths W1 and W2 through which the cool air passes. Accordingly, this prevents clogging due to the frost concentrated on the lower part of the cooler 310, and allows the cool air to pass through the air paths W1 and W2 even if such clogging is caused in the lower part of the cooler 310 as a result of the frost formation, thus allowing blowing the cool air upward.

As described above, according to the present invention, it is possible to defrost the entire cooler 310 using the radiant heater 312 and the contact heater 313, without raising the temperature of the heater too high.

As described above, the cooling unit 300 includes the sheet-like front plate 321 and the rear plate 322 made of metal; however, an aluminum foil sheet, instead of the front plate 321, may be attached to the cover recessed portion 340a, and an aluminum foil sheet, instead of the rear plate 322, may be attached to an inner-case recessed portion 400a. Accordingly, the cover recessed portion 340a forms a return-air path for the refrigerant between the cooler 310 and the cover 340, and the inner-case recessed portion 400a forms a return-air path for the refrigerant between the cooler 310 and the inner case 400, thus preventing concentration of the frost on the lower face of the cooler 310.

Next, the layout and configuration of the holding member 330 and the cover 340 will be described in detail.

FIGS. 11 and 12 are diagrams for describing the layout and configuration of the holding member 330. Specifically, FIG. 11 is a perspective view showing a state in which the holding member 330 holds the cooler 310, and FIG. 12 is a diagram of the holding member 330 and the cooler 310 shown in FIG. 11 as viewed from the front. Note that for convenience of description, the contact heater 313 of the cooler 310 is omitted from the figure.

As shown in FIGS. 11 and 12, the holding member 330 is provided on each side of the cooler 310 to hold the cooler 310. Specifically, the holding member 330 includes a protrusion 331 for holding the cooler 310. The protrusion 331 is a portion protruding toward the cooler 310 at a position that levels a center height of the holding member 330.

In addition, FIG. 12 shows an enlarged view of the protrusion 331. As shown in the enlarged view, the protrusion 331 holds the cooler 310 by holding the cooling pipe 311 of the cooler 310. Then, the holding member 330 is fixed to the heat-insulating main body 150. Thus, the holding member 330 is placed between the inner lateral wall of the heat-insulating main body 150 and the lateral side of the cooler 310 to hold the cooler 310.

In addition, as shown in the enlarged view, the protrusion 331 includes a holding member hole 332 that is a circular hole.

FIGS. 13 and 14 are diagrams for describing the layout and configuration of the cover 340. Specifically, FIG. 13 is a perspective view showing a state before the cover 340 is attached to the holding member 330, and FIG. 14 is a perspective view showing a state after the cover 340 is attached to the holding member 330. Note that for convenience of description, the contact heater 313 in the cooler 310 and the reflective plate 320 are omitted from FIG. 13.

As shown in FIG. 13, the cover 340 is placed in front of the holding member 330 that holds the cooler 310. Here, as shown in FIG. 12, the protrusion 331 of the holding member 330 includes two holding member holes 332. In addition, two cover holes 342 are provided at a position corresponding to these holding member holes 332 in the cover 340.

Thus, as shown in FIG. 14, the cover 340 is placed in front of the holding member 330 to cover the front part of the cooler 310. Then, overlapping of the holding member holes 332 of the holding member 330 with the cover holes 342 corresponding to the holding member holes 332 allows insertion of a rod-shaped member through both holes, thus allowing attachment of the cover 340 to the holding member 330.

Thus, the cover 340 is attached to the inner wall of the heat-insulating main body 150 via the holding member 330.

As described above, the holding member 330 allows the heat-insulating main body 150 to hold the cooler 310 and also attaches the cover 340 to the heat-insulating main body 150. The following will describe an advantageous effect produced by providing such a holding member 330.

FIGS. 15A and 15B are diagrams for describing the advantageous effect produced by providing the holding member 330. Specifically, FIG. 15A is a diagram showing a conventional configuration which does not include the holding member 330, and FIG. 15B is a diagram showing a configuration including the holding member 330.

As shown in FIG. 15A, when the holding member 330 is not included, for attachment of the cover 340 to the inner wall of the heat-insulating main body 150, it is necessary to provide a space (portion C shown in the figure) for attachment of the cover 340. Thus, the horizontal width of the cooler 310 is limited by the space.

In contrast, as shown in FIG. 15B, when the holding member 330 is included, it is possible to attach the cover 340 to the holding member 330. Thus, it is not necessary to provide a space for attachment of the cover 340 to the inner wall of the heat-insulating main body 150. This allows increasing the horizontal width of the cooler 310 compared to the case shown in FIG. 15A.

Thus far, the refrigerator according to the present invention has been described using the embodiment above, but the present invention is not limited to this embodiment.

In other words, the embodiment disclosed herein should be considered not limitative but illustrative in all aspects. The scope of the present invention is described not by the description above but by the claims, and is to include all the variations and modifications within the meaning and the scope equivalent to those of the claims.

For example, according to the present embodiment, the vertical lengths of the front plate 321 and the rear plate 322 have been described as half the vertical length of the cooler 310. However, the vertical lengths of the front plate 321 and the rear plate 322 are not limited to half the vertical length of the cooler 310, but may be any length.

FIG. 16 is a diagram showing a variation of the present embodiment, in which a front plate and a rear plate have lengths different from each other.

As shown in the figure, the vertical lengths of the front plate 323 and the rear plate 324 are the same as the vertical length of the cooler 310. In addition, below the cooler 310, only the radiant heater 312 is provided, and the contact heater 313 is not provided. According to the present configuration, it is possible to transmit, through the front plate 323 and the rear plate 324, the radiant heat from the radiant heater 312 to the top of the cooler 310.

In addition, according to the present embodiment, the front plate 321 and the rear plate 322 have been described as including the groove 321a and the groove 322a, respectively. However, both of the front plate 321 and the rear plate 322 need not include the grooves, but only at least one of the front plate 321 and the rear plate 322 needs to include one of the grooves.

The present invention is applicable to a refrigerator.