JP7486864B2 - Defrosting device and refrigerator equipped with defrosting device - Google Patents

Description

The present invention relates to a defrosting device that removes frost from the evaporator of a refrigerator and a refrigerator equipped with this defrosting device.

Refrigerators equipped with a defrosting device having a glass tube heater below the evaporator are widely used to remove frost that has formed on the evaporator. In such refrigerators, the outer surface temperature of the glass tube heater must be kept sufficiently lower than the flammable temperature of the solvent flowing inside the evaporator. However, if the power input to the glass tube heater is reduced in order to lower the outer surface temperature of the glass tube heater, sufficient defrosting performance may not be obtained. In particular, even if the frost on the upper evaporator melts due to natural convection heat transfer by the glass tube heater, the water that melts from the evaporator may refreeze in the tray located below the glass tube heater.

To address this issue, a defrosting device has been proposed that uses a defrosting heater with a heating element inside a double glass tube (see, for example, Patent Document 1). In the defrosting device described in Patent Document 1, by using a double glass tube, even though the outer surface temperature of the glass tube heater is low, it is possible to apply a sufficient amount of heat to melt the frost that has re-frozen in the tray.

JP 2004-198097 A

However, glass tube heaters with double glass tubes have a problem in that they are expensive to manufacture, and the manufacturing costs of defrosters equipped with such glass tube heaters and refrigerators equipped with such defrosters are also high.

Therefore, the object of the present invention is to solve the above problems and to provide a defrosting device that can be manufactured at low cost and has sufficient defrosting performance, and a refrigerator equipped with this defrosting device.

The defrosting device of the present invention is
A defrosting heater having a heating element in a single glass tube having a circular cross section perpendicular to the longitudinal direction;
a roof portion disposed above the glass tube, extending along the longitudinal direction of the glass tube, and formed by forming a metal thin plate into an upwardly convex shape;
a tray disposed below the glass tube, extending along the longitudinal direction of the glass tube, and having an opening at the bottom;
a drain pipe extending downward from the opening;
Equipped with
In a cross section perpendicular to the longitudinal direction of the glass tube,
the roof portion has a top located on a vertical line passing through an approximate center of the glass tube, and is symmetrical with respect to the vertical line at least within a predetermined range on both sides of the vertical line;
In a cross section along the longitudinal direction of the glass tube including the perpendicular line,
The roof portion is formed such that end regions on both sides in the longitudinal direction are inclined downward so as to reflect radiant heat from below downward,
The opening is located directly below the glass tube.

According to the present invention, the manufacturing cost of the defrosting device can be reduced by using a single glass tube. Even if the power input to the defrosting heater is suppressed in order to lower the outer surface temperature of the glass tube, the roof portion can reflect the radiant heat from the defrosting heater to the receiving tray side, and the frost re-frozen in the receiving tray can be melted. In particular, in a cross section perpendicular to the longitudinal direction of the glass tube, the upward convex shape of the roof portion is formed symmetrically with respect to the perpendicular line at least within a predetermined range on both sides of the perpendicular line passing through the approximate center of the glass tube. Furthermore, in a cross section along the longitudinal direction of the glass tube including the perpendicular line, the upward convex shape of the roof portion is formed at an incline so as to reflect the radiant heat from below to the downward side in the end regions on both sides. In other words, the roof portion is formed in a shape that enhances reflection on all four sides. This allows radiant heat with little variation and bias to enter the main part of the receiving tray, except directly below the glass tube.

In addition, since the opening of the tray is located directly under the glass tube, the radiant heat from the defrosting heater is directly incident on the opening and its surroundings, which melts the frost that has re-frozen on the tray and can be reliably discharged through the opening and the drain pipe.
As described above, it is possible to provide a defrosting device that can be manufactured at low cost and has sufficient defrosting performance.

The present invention also provides a method for producing a method for manufacturing a semiconductor device comprising the steps of:
In the height direction, the position of the lower end of the roof portion is disposed at the same position as or higher than the position of the upper end of the glass tube;
The present invention is characterized in that, in the height direction, the position of the top of the roof portion is located at the same position as or lower than the position obtained by adding a length equivalent to 1.5 times the outer diameter of the glass tube to the position of the upper end of the glass tube.

According to the present invention, the position of the lower end of the roof is located at the same position as or above the position of the upper end of the glass tube, so that the frost on the evaporator above can be reliably melted by heat transfer by natural convection. In addition, the position of the top of the roof in the height direction is located at the same position as or below the position of the top end of the glass tube plus a length equivalent to 1.5 times the outer diameter of the glass tube, so that the glass tube can be placed close to the evaporator to enhance the effect of melting the frost on the evaporator. At the same time, since the top of the roof is not too far from the tray, the roof strongly reflects the radiant heat from the defrosting heater toward the tray, enhancing the effect of melting the frost in the tray.
By arranging the roof portion as described above, the frost on the evaporator and the tray can be effectively melted, thereby achieving high defrosting performance.

The present invention also provides a method for producing a method for manufacturing a semiconductor device comprising the steps of:
In a cross section perpendicular to the longitudinal direction of the glass tube, the width dimension at the lower end of the roof portion is within a range of two to three times the outer diameter of the glass tube.

By setting the width dimension at the bottom end of the roof to within a range of two to three times the outer diameter of the glass tube, the frost on both the evaporator and the tray can be melted in a balanced and effective manner.

The present invention also provides a method for producing a method for manufacturing a semiconductor device comprising the steps of:
The defrosting member is made of a bent metal rod.
The defrosting member is
A hook portion is formed on one end of the metal bar and is rotatably inserted into a hole provided in the roof portion;
a heat receiving portion connected to the hook portion and extending obliquely downward while contacting the roof portion;
a bypass portion connected to the heat receiving portion and bent to bypass the glass tube;
a heat dissipation portion connected to the bypass portion and extending downward into the inside of the tray and the inside of the drain pipe;
The present invention is characterized by having the following.

According to the present invention, the defrosting member rotatably attached to the roof by the hook portion is arranged so that the heat receiving portion contacts the roof by gravity, and can receive heat from the defrosting heater via the metal roof. Also, the bypass portion allows the heat dissipation portion to be arranged inside the tray and inside the drain pipe by gravity without interfering with the glass tube. The heat received by the roof is thermally conducted to the heat dissipation portion extending downward via the bypass portion, and the heat can be supplied from the heat dissipation portion to the frost and water in the tray and drain pipe.
As described above, by using the defrosting member, it is possible to manufacture the device at low cost and to effectively supply heat from the defrosting heater to the frost and water in the tray and drain pipe.

In addition, the refrigerator of the present invention is
The present invention is characterized by comprising the above-mentioned defrosting device.

The refrigerator of the present invention can also achieve any of the above-mentioned effects.

As described above, the present invention provides a defrosting device that can be manufactured at low cost and has sufficient defrosting performance, and a refrigerator equipped with this defrosting device.

1 is a side cross-sectional view illustrating a schematic diagram of an example of a refrigerator equipped with a defrosting device according to an embodiment of the present invention. 1 is a perspective view showing a schematic overview of a defrosting device according to a first embodiment of the present invention; FIG. 3 is a diagram showing a cross section perpendicular to the longitudinal direction of a glass tube as viewed from the X-axis direction in FIG. 2, and is a side cross-sectional view that typically shows a defrosting device according to a first embodiment of the present invention. FIG. 2 is a side cross-sectional view showing a cross section along the longitudinal direction of a glass tube including a perpendicular line passing through approximately the center of the circular outer shape of the glass tube, and is a schematic side cross-sectional view showing a defrosting device according to a first embodiment of the present invention. FIG. 3 is a side cross-sectional view showing a cross section perpendicular to the longitudinal direction of the glass tube as viewed from the X-axis direction in FIG. 2, and is for explaining the arrangement of the roof portion according to an embodiment of the present invention. FIG. 3 is a side cross-sectional view showing a cross section perpendicular to the longitudinal direction of a glass tube as viewed from the X-axis direction in FIG. 2, and is a schematic side cross-sectional view showing a defrosting device according to a second embodiment of the present invention. FIG. 3 is a side cross-sectional view showing a cross section perpendicular to the longitudinal direction of a glass tube as viewed from the X-axis direction in FIG. 2, and is a schematic side cross-sectional view showing a defrosting device according to a third embodiment of the present invention. FIG. 4 is a side cross-sectional view showing a cross section perpendicular to the longitudinal direction of a glass tube as viewed from the X-axis direction in FIG. 2, and is a schematic side cross-sectional view showing a defrosting device according to a fourth embodiment of the present invention. FIG. 2 is a perspective view for explaining a defrosting member according to an embodiment of the present invention.

Hereinafter, an embodiment for carrying out the present invention will be described with reference to the drawings. Note that the defrosting device described below is intended to embody the technical concept of the present invention, and unless otherwise specified, the present invention is not limited to the following.
In each drawing, the same reference numerals may be used for components having the same function. In consideration of the explanation or ease of understanding of the main points, the embodiments and examples may be shown for convenience, but partial replacement or combination of the configurations shown in different embodiments is possible. In the embodiments described below, the description of the matters common to the above will be omitted, and only the differences will be described. In particular, the same action and effect due to the same configuration will not be mentioned in each embodiment or example. The size and positional relationship of the components shown in each drawing may be exaggerated to clarify the explanation. In the following description and drawings, the X-axis, Y-axis, and Z-axis are shown assuming that the heater is placed inside a refrigerator installed on the floor. The Z-axis indicates the vertical direction, and the X-axis indicates the longitudinal direction of the glass tube 12 constituting the defrost heater 10 described later.

(Refrigerator equipped with the defrosting device of the present invention)
Fig. 1 is a side cross-sectional view showing a schematic example of a refrigerator 100 equipped with a defrosting device 2 according to an embodiment of the present invention. The refrigerator 100 shown in Fig. 1 includes a freezer compartment 102A and a refrigerator compartment 102B. Inlet flow paths 104A, 104B separated by a partition plate 106 are provided on the rear side of the freezer compartment 102A and the refrigerator compartment 102B. An evaporator 110 is disposed in the inlet flow path 104A on the freezer compartment 102A side, and a fan 130 is disposed above the evaporator 110. A defrosting device 2 according to each embodiment described below is disposed below the evaporator 110.

A compressor 120 connected to the evaporator 110 is disposed in an external machine room on the rear side of the freezer compartment 102A. The refrigerant (gas) compressed by the compressor 120 is liquefied in the condenser, the liquefied refrigerant absorbs heat from the gas inside the compartment and vaporizes in the evaporator 110, and the vaporized refrigerant is compressed again by the compressor 120, repeating this cycle. A damper 140 is disposed between the inlet flow path 104A on the freezer compartment 102A side and the inlet flow path 104B on the refrigerator compartment 102B side. In FIG. 1, the damper 140 is shown in a closed state.

As shown by the dotted arrows in FIG. 1, when the damper 140 is closed, the compressor 120 and the fan 130 are driven, causing the gas in the freezer compartment 102A to flow, and the cold air that has passed through the evaporator 110 flows into the freezer compartment 102A from the air outlet 106A provided in the partition plate 106. The gas that has flowed in circulates within the freezer compartment 102A and returns again to the lower side of the evaporator 110 in the inlet flow path 104A. This circulation of the gas that has passed through the evaporator 110 and been cooled can cool the freezer compartment 102A. When the damper 140 is open, cold air also circulates to the refrigerator compartment 102B side.

Frost forms on the surface of the heat exchange tube of the evaporator 110 due to condensation of moisture contained in the air to be cooled. If a large amount of frost forms on the heat exchange tube, the cooling performance decreases, so the evaporator 110 needs to be defrosted periodically. For this reason, a defrosting device 2 is disposed below the evaporator 110. The defrosting device 2 is provided with a defrosting heater 10, and by turning on the defrosting heater 10 when the compressor 120 and the fan 130 are not in operation, the heat exchange tube can be warmed and defrosted. The water that melts off the frost on the evaporator 110 flows from the drain pipe 40 of the defrosting device 2 through the drain pipe 150 of the refrigerator 100 and is discharged into the evaporation tray 160 disposed in the machine room.

(Defrosting device according to the first embodiment)
FIG. 2 is a perspective view showing a schematic overview of the defrosting device 2 according to the first embodiment of the present invention. FIG. 3 is a side cross-sectional view showing a cross section perpendicular to the longitudinal direction of the glass tube 12 as viewed from the X-axis direction in FIG. 2, and is a side cross-sectional view showing a schematic view of the defrosting device 2 according to the first embodiment of the present invention. FIG. 4 is a side cross-sectional view showing a cross section along the longitudinal direction of the glass tube including a perpendicular line passing through the approximate center of the circular outer shape of the glass tube, and is a side cross-sectional view showing a schematic view of the defrosting device according to the first embodiment of the present invention. In FIG. 4, the description of the receiving tray is omitted. Next, the defrosting device 2 according to the first embodiment of the present invention will be described with reference to FIG. 2 to FIG. 4.

The defroster 2 according to this embodiment includes a defroster heater 10 having a heating element in a single quartz glass tube 12. The defroster 2 also includes a heater cover 20 that is disposed above the glass tube 12 and extends along the longitudinal direction of the glass tube 12, and has a roof portion 22 formed of a metal thin plate formed into an upwardly convex shape. The defroster 2 also includes a tray 30 that is disposed below the glass tube 12 and extends along the longitudinal direction of the glass tube 12, and a drain pipe 40 that extends downward from an opening 32 provided at the bottom of the tray 30. FIG. 3 shows a schematic diagram of the drain pipe 40 shown in FIG. 2.

The defrosting device 2 according to this embodiment further comprises a defrosting member 50 made of a bent metal rod. The defrosting member 50 comprises a hook portion 52 formed on one end of the metal rod and rotatably inserted into a hole 26 provided in the thin metal plate constituting the roof portion 22, a heat receiving portion 54 connected to the hook portion 52 and extending diagonally downward while contacting the thin metal plate constituting the roof portion 22, a detour portion 56 connected to the heat receiving portion 54 and bent to detour around the glass tube 12, and a heat dissipation portion 58 connected to the detour portion 56 and extending downward to the inside of the receiving tray 30 and the inside of the drain pipe 40.

<Defrosting heater>
The glass tube 12 constituting the defrost heater 10 according to this embodiment has a long and thin cylindrical shape. A heating element made of a metal wire such as a nichrome wire is disposed inside the glass tube 12. A coil heater made of a metal wire wound in a coil shape is disposed in the heat generating region in the center of the glass tube 12, and the metal wire extends outward from both ends of the coil heater. Both ends of the glass tube 12 are covered with cap parts 14 formed of a material having excellent heat resistance and electrical insulation such as silicone rubber. The metal wire extending from both sides of the coil heater extends to the outside of the glass tube 12 via the cap parts 14 and is electrically connected to an external cable.

To comply with the IEC standard, the input power is controlled so that the outer surface temperature of the glass tube 12 during heat generation is 360°C or less. Even with this type of input power control, it is possible to perform practically sufficient defrosting of the evaporator 110, as will be described in detail later.

<Heater cover>
The heater cover 20 extends along the longitudinal direction of the glass tube 12 and includes a roof portion 22 formed of a thin metal plate in an upwardly convex shape, and brackets 24 provided on both longitudinal sides of the roof portion 22. The cap portions 14 on both ends of the glass tube 12 are inserted into roughly C-shaped openings provided in the brackets 24, and the heater cover 20 is attached to the defrost heater 10.
In this embodiment, an aluminum thin plate having high reflectivity and high thermal conductivity is used as the metal thin plate constituting the roof portion 22. However, the metal thin plate is not limited to this, and any other metal thin plate including copper can be used. The aluminum thin plate can be bent to form a convex shape, or two aluminum thin plates can be joined together to form a convex shape.

The roof portion 22 is formed by forming a metal thin plate into an upward convex shape in a cross section perpendicular to the longitudinal direction of the glass tube 12 as viewed from the X-axis direction, and this upward convex shape is symmetrical with respect to the perpendicular line VL at least within a predetermined range S on both sides of the perpendicular line VL passing through the approximate center G of the circular outer shape of the glass tube 12. Here, the predetermined range S on both sides of the perpendicular line VL means a range of width S on the left and right from the perpendicular line VL in the Y-axis direction perpendicular to the perpendicular line VL in two regions divided by the perpendicular line VL along the Z-axis direction. The upward convex shape of the roof portion 22 has a first region 22A and a second region 22B that are two flat plates. As described later, the reflective surfaces of the first region 22A and the second region 22B can be configured with flat surfaces or smoothly curved surfaces.

Furthermore, as shown in Fig. 4, in a cross section along the longitudinal direction of the glass tube 12, the roof portion 22 has a third region 22C and a fourth region 22D at both end regions in the longitudinal direction, which are inclined downward so as to reflect radiant heat from below downward. That is, as shown in Fig. 2, the roof portion 22 has a hipped roof-like structure composed of four thin plate-like members, the first to fourth regions 22A to 22D, and is formed into a shape that enhances reflection on all four sides. The reflecting surfaces of the third region 22C and the fourth region 22D can be composed of flat surfaces or smoothly curved surfaces.
With the above-mentioned configuration, the radiant heat from the defrosting heater 10 can be reflected downward and incident on the main portion of the lower tray 30. This makes it possible to melt the frost that has re-frozen in the tray 30.

<Receptacle and drain pipe>
The saucer 30 extends along the longitudinal direction of the glass tube 12, has a bottom 30A and a side wall 30B surrounding the bottom 30A, and is open at the top. An opening 32 is provided at a position approximately at the center of the longitudinal direction of the bottom 30A of the saucer 30. The bottom 30A of the saucer 30 is inclined so that the opening 32 is at the lowest height. This allows water that falls from the evaporator 110 above to flow through the bottom 30A of the saucer 30 and into the opening 32. A drain pipe 40 is attached to the opening 32 provided in the bottom 30A of the saucer 30, and the drain pipe 40 extends downward from the opening 32.

In a cross section perpendicular to the longitudinal direction of the glass tube 12 as viewed from the X-axis direction, the opening 32 of the tray 30 is located directly below the glass tube 12. With this arrangement, the opening 32 and the area around it can directly receive radiant heat from the defrosting heater 10, and can melt the frost that has re-frozen in the tray 30.
The tray 30 is preferably made of a metal material having high thermal conductivity such as aluminum. In consideration of the ease of mounting the defroster 2 to the refrigerator 100, the drain pipe 40 is preferably made of an elastic resin material or the like.

(Roof arrangement)
Fig. 5 is a cross-sectional view showing a cross section perpendicular to the longitudinal direction of the glass tube as viewed from the X-axis direction in Fig. 2, and is a side cross-sectional view for explaining the arrangement of the roof portion 22 according to the embodiment of the present invention. In Fig. 5 and Figs. 6 to 8 described later, the radiant heat emitted from the defrost heater 10 is indicated by dotted arrows, and the upward flow of the surrounding gas heated by the defrost heater 10 due to natural convection is indicated by dashed arrows. In Fig. 5, the defrosting device according to the first embodiment shown in Fig. 3 is used as an example for explanation, but the function of the roof portion 22 is basically the same in the defrosting devices according to the second to fourth embodiments described later using Figs. 6 to 8.

The upwardly convex shape of the roof portion 22 is symmetrical with respect to the perpendicular line VL within a predetermined range S on both sides of the perpendicular line VL passing through approximately the center G of the circular outer shape of the glass tube 12 in a cross section perpendicular to the longitudinal direction of the glass tube 12 as viewed from the X-axis direction. In the first embodiment, the predetermined range S coincides with the entire area of the roof portion 22, and the entire area is symmetrical with respect to the perpendicular line VL. However, this is not limited to this, and other cases will be described in detail later.

The predetermined range S is preferably determined according to the width dimension of the tray 30 perpendicular to the longitudinal direction as viewed from the X-axis direction. When both ends of the tray 30 in the width direction are equidistant from the perpendicular line VL, it is preferable that the upward convex shape of the roof 22 is symmetrical with respect to the perpendicular line VL up to the range where the reflected light reaches both ends of the tray 30. When the distances from the perpendicular line VL to both ends of the tray 30 in the width direction are different, it is preferable that the upward convex shape of the roof 22 is symmetrical with respect to the perpendicular line VL at least up to the range where the reflected light reaches the end closer to the perpendicular line VL. This allows radiant heat with little variation and bias to be incident on the main part of the tray 30, and frost in the tray 30 can be efficiently melted.

In a cross section perpendicular to the longitudinal direction of the glass tube 12 as viewed from the X-axis direction, the first region 22A and the second region 22B are shown as two sides connected by a vertex P located on the perpendicular line VL. The angle θ between the first region 22A and the perpendicular line VL is approximately equal to the angle θ between the second region 22B and the perpendicular line VL. Furthermore, in the example shown in FIG. 5, the lengths of the first region 22A and the second region 22B are also equal.

This means that in a cross section perpendicular to the longitudinal direction of the glass tube 12 as viewed from the X-axis direction, the first region 22A and the second region 22B form two equal sides of an isosceles triangle with the vertex at point P located on the perpendicular line VL.

As shown by the two-dot chain line in FIG. 5, when the first region 22A and the second region 22B are each extended diagonally downward, they intersect with a horizontal line extending from the bottom surface of the tray 30. This forms the upper half of a parallelogram. The center of the opening 32 of the tray 30 then approximately coincides with the position of the perpendicular line VL. In other words, the opening 32 of the tray 30 is located at the center of a parallelogram whose two sides are the upwardly convex roof portion 22 and its extension line.

This arrangement allows the radiant heat emitted upward from the defrost heater 10 to be reflected downward by the roof 22, allowing the radiant heat to be incident on the main part of the tray 30 except for the area directly below the glass tube 12 with little variation or bias. Directly below the glass tube 12, there are areas where the reflected light from the roof 22 does not reach, but in such areas, the radiant heat emitted downward from the defrost heater 10 directly enters. This allows the frost that has re-frozen in the main part on the tray 30 to melt efficiently. The melted water flows into the drain pipe 40 through the opening 32, flows through the drain pipe 150 of the refrigerator 100, and is discharged into the evaporation tray 160 located in the machine room.

5, in the height direction (Z-axis direction), position H1 of the lower end of the roof portion 22 is disposed above position H0 of the upper end of the glass tube 12. However, this is not limited to this, and position H1 of the lower end of the roof portion 22 may be disposed at the same position as position H0 of the upper end of the glass tube 12. In other words, in the height direction (Z-axis direction), position H1 of the lower end of the roof portion 22 is disposed at the same position as or above position H0 of the upper end of the glass tube 12.
With this setting, the gas around the glass tube 12 heated by the defrosting heater 10 can be efficiently moved upward by natural convection. This allows heat to be supplied to the evaporator 110 by natural convection heat transfer, so that the frost on the evaporator 110 can be reliably melted.

In addition, in the height direction (Z-axis direction), the position H2 of the top P of the roof portion 22 is disposed at the same position as or below the position H0 of the upper end of the glass tube 12 plus a length equivalent to 1.5 times the outer diameter of the glass tube 12. With this setting, the defrost heater 10 can be disposed relatively close to the evaporator 110, thereby improving the effect of melting the frost on the evaporator 110. At the same time, since the top P of the roof portion 22 is not far away from the tray 30, the radiant heat from the defrost heater 10 is strongly reflected by the roof portion 22 toward the tray 30, improving the effect of melting the frost in the tray 30.
By arranging the roof portion 22 as described above, the frost on the evaporator 110 and the tray 30 can be effectively melted, thereby achieving high defrosting performance.

In addition, in this embodiment, in a cross section perpendicular to the longitudinal direction of the glass tube 12 as viewed from the X-axis direction, the width dimension W at the lower end of the roof portion 22 is within a range of two to three times the outer diameter D of the glass tube. In addition, if the distance between the end of the lower end of the roof portion 22 in the width direction and the outer diameter of the glass tube 12 is M, then there is a relationship of 0.5D <= M <= D.

If the width dimension W at the bottom end of the roof portion 22 is not much larger than the outer diameter of the glass tube 12, the heat generated by the defrost heater 10 cannot be sufficiently reflected downward. On the other hand, if the width dimension W at the bottom end of the roof portion 22 is considerably larger than the outer diameter of the glass tube 12, it becomes difficult to supply heat to the upper evaporator 110 side by natural convection.
Therefore, by setting the width dimension W at the lower end of the roof portion 22 within the range of two to three times the outer diameter of the glass tube 12, the frost on both the evaporator 110 and the tray 30 can be melted effectively in a balanced manner.
A similar relationship is shown in a cross section perpendicular to the longitudinal direction of the glass tube 12 as viewed in a direction 180 degrees opposite to the X-axis direction.

(Defrosting device according to the second embodiment)
FIG. 6 is a diagram showing a cross section perpendicular to the longitudinal direction of the glass tube as viewed from the X-axis direction in FIG. 2, and is a side cross-sectional view that typically shows a defrosting device according to a second embodiment of the present invention.
In the defrosting device 2 according to the second embodiment, the roof portion 22 also has an upwardly convex shape in which two flat plate-like first and second regions 22A and 22B are connected to each other. However, in a cross section perpendicular to the longitudinal direction of the glass tube 12 as viewed from the X-axis direction, the length of the second region 22B is the same as in the first embodiment, but the length of the first region 22A is longer than that in the first embodiment.

As shown in FIG. 6, in a cross section perpendicular to the longitudinal direction of the glass tube 12 as viewed from the X-axis direction, the upward convex shape of the roof portion 22 is symmetrical about the perpendicular line VL within a certain range S on both sides of the perpendicular line passing through the approximate center G of the circular outer shape of the glass tube 12, but is not symmetrical about the perpendicular line VL in all regions. In one first region 22A of the roof portion 22, it is extended by a width T.

In the first embodiment described above, in a cross section perpendicular to the longitudinal direction of the glass tube 12 as viewed from the X-axis direction, the widthwise ends of the lower receiving tray 30 are located at approximately the same distance from the perpendicular line VL in the Y-axis direction perpendicular to the perpendicular line VL, whereas in the second embodiment, both widthwise ends of the receiving tray 30 are located at different distances from the perpendicular line VL.
The upward convex shape of roof portion 22 is symmetrical with respect to perpendicular line VL up to the range where reflected light is incident on the end portion closer to perpendicular line VL in the width direction of tray 30 (the end portion on the right side in the drawing). By adjusting the length of roof portion 22, reflected light is also incident on the other end portion (the end portion on the left side in the drawing).
In a cross section perpendicular to the longitudinal direction of the glass tube 12 as viewed in a direction 180 degrees opposite to the X-axis direction, the left and right are reversed but a similar relationship is shown.

(Defrosting device according to the third embodiment)
FIG. 7 is a diagram showing a cross section perpendicular to the longitudinal direction of the glass tube 12 as viewed from the X-axis direction in FIG. 2, and is a side cross-sectional view that typically shows a defrosting device 2 according to a third embodiment of the present invention.
In the defrosting devices according to the first and second embodiments described above, the roof portion 22 is composed of two flat plate-shaped first and second regions 22A and 22B, whereas in the third embodiment, the roof portion 22 is composed of a smoothly curved surface.

Even in this case, by appropriately determining the curvature of the curved surface of the roof portion 22, as shown in Figure 7, the radiant heat emitted upward from the defrost heater 10 can be reflected downward by the roof portion 22 and made to enter the main part of the tray 30 except for the area blocked by the glass tube 12.
In the third embodiment, similarly to the first embodiment, the entire region of the roof portion 22 is symmetrical with respect to the perpendicular line VL passing through approximately the center G of the circular outer shape of the glass tube 12. A similar relationship is also shown in a cross section perpendicular to the longitudinal direction of the glass tube 12 as viewed from a direction 180 degrees opposite to the X-axis direction.

(Defrosting device according to the fourth embodiment)
FIG. 8 is a diagram showing a cross section perpendicular to the longitudinal direction of the glass tube 12 as viewed from the X-axis direction in FIG. 2, and is a side cross-sectional view that typically shows a defrosting device 2 according to a fourth embodiment of the present invention.
In the fourth embodiment, the roof portion 22 is also formed of a smoothly curved surface. In a cross section perpendicular to the longitudinal direction of the glass tube 12 as viewed from the X-axis direction, the upwardly convex shape of the roof portion 22 is symmetrical with respect to the perpendicular line VL within a certain range S on both sides of the perpendicular line passing through the approximate center G of the circular outer shape of the glass tube 12, but the roof portion 22 is not symmetrical with respect to the perpendicular line VL in the entire region. One of the first regions 22A of the roof portion 22 is extended by a width T.

In the fourth embodiment, in a cross section perpendicular to the longitudinal direction of the glass tube 12 as viewed from the X-axis direction in FIG. 2, both ends in the width direction of the tray 30 are positioned at different distances from the perpendicular line VL.
The upward convex shape of the roof 22 is symmetrical with respect to the perpendicular line VL up to the range where the reflected light is incident on the end portion closer to the perpendicular line VL in the width direction of the tray 30 (the end portion on the right side in the drawing). By adjusting the length of the roof 22, the reflected light is also incident on the other end portion (the end portion on the left side in the drawing). In a cross section perpendicular to the longitudinal direction of the glass tube 12 as viewed from a direction 180 degrees opposite to the X-axis direction, the left and right are reversed, but a similar relationship is shown.

As described above, in any of the defrosting devices 2 according to the first to fourth embodiments of the present invention, the defrosting heater 10 has a heating element inside a single glass tube 12 having a circular cross section perpendicular to the longitudinal direction, the roof portion 22 is arranged above the glass tube 12, extends along the longitudinal direction of the glass tube 12, and is made of a thin metal plate formed into an upwardly convex shape, the tray 30 is arranged below the glass tube 12, extends along the longitudinal direction of the glass tube 12, and has an opening 32 formed at the bottom, and the drain 32 extends downward from the opening 32. In a cross section perpendicular to the longitudinal direction of the glass tube 12, the roof portion 22 has a top P located on a perpendicular line VL passing through the approximate center G of the glass tube 12, and is symmetrical with respect to the perpendicular line VL within at least a specified range on both sides of the perpendicular line VL. In a cross section along the longitudinal direction of the glass tube 12 including the perpendicular line VL, the roof portion 22 is formed with end regions on both sides in the longitudinal direction inclined downward so as to reflect radiant heat from below downward, and the opening 32 is located directly below the glass tube 12.

By using a single glass tube 12, the manufacturing cost of the device can be reduced. Even if the power input to the defrost heater 10 is suppressed to lower the outer surface temperature of the glass tube 12, the roof portion 22 can reflect the radiant heat from the defrost heater 10 to the tray side 30, melting the frost in the tray 30. In particular, the upward convex shape of the roof portion 22 is symmetrical with respect to the perpendicular line VL at least within a predetermined range S on both sides of the perpendicular line VL passing through the approximate center G of the glass tube 12, and in the longitudinal direction of the glass tube 12 (the X-axis direction shown in FIG. 2), the end regions on both sides (see 22C and 22D in FIG. 4) are inclined so as to reflect the radiant heat from below downward, and the opening 32 of the tray 30 is located directly below the glass tube 12. As a result, the reflected heat from the roof portion 22 and the radiant heat directly received from the defrost heater 10 can cause radiant heat with little variation or bias to enter the main part of the tray 30.

As a result, the frost on the evaporator 110 can be melted and discharged through the opening 32 of the tray 30 and the drain pipe 40. As a result, it is possible to provide a defrosting device 2 that can be manufactured at low cost and has sufficient defrosting performance.

In the defrosting device 2 according to the first to fourth embodiments, the position H1 of the lower end of the roof 22 is located at the same position as or above the position H0 of the upper end of the glass tube 12 in the height direction (Z-axis direction), so that the frost on the evaporator 110 can be effectively melted by natural convection heat transfer. Furthermore, the position H2 of the top P of the roof 22 is located at the same position as or below the position obtained by adding a length equivalent to 1.5 times the outer diameter of the glass tube 12 to the position H0 of the upper end of the glass tube 12 in the height direction (Z-axis direction), so that the effect of melting the frost on the evaporator 110 can be improved, and the effect of melting the frost in the tray 30 can be improved.
By arranging the roof portion 22 as described above, the frost on the evaporator 110 and the tray 30 can be effectively melted, thereby achieving high defrosting performance.

In addition, according to the defrosting device 2 of the first to fourth embodiments, the width dimension W at the lower end of the roof portion 22 is within a range of two to three times the outer diameter D of the glass tube 12, so that the frost on both the evaporator 110 and the receiving tray 30 can be melted effectively in a balanced manner.

(Defrosting material)
9 is a perspective view for explaining the defrosting member according to the embodiment of the present invention, in which the shape of the roof portion 22 is simply shown.
Each of the defrosting devices 2 according to the above-mentioned embodiments includes a defrosting member 50 made of a bent metal rod. As shown in Fig. 3 or 9, the defrosting member 50 has a hook portion 52 formed on one end of the metal rod and rotatably inserted into a hole 26 provided in the thin metal plate constituting the roof portion 22. The defrosting member 50 further has a heat receiving portion 54 connected to the hook portion 52 and extending obliquely downward while contacting the thin metal plate constituting the roof portion 22. The defrosting member 50, which is rotatably attached to the roof portion 22 by the hook portion 52 at one end, is suspended by gravity, and the heat receiving portion 54 extends obliquely downward while contacting the thin metal plate constituting the roof portion 22.

The defrosting member 50 further includes a bypass section 56 that is connected to the heat receiving section 54 and is bent to bypass the glass tube 12. The heat receiving section 54 is fixed in position by gravity against the thin metal plate that constitutes the roof section 22, so that the bypass section 56 can be reliably maintained at a position separated from the glass tube 12. The defrosting member 50 further includes a heat dissipation section 58 that is connected to the bypass section 56 and extends downward into the interior of the receiving tray 30 and the interior of the drain pipe 40. The defrosting member 50 terminates at the end of the heat dissipation section 58.

The defrosting member 50 is rotatably attached to the roof 22 by the hook 52, and the heat receiving portion 54 comes into contact with the roof 22 due to gravity, so that the heat receiving portion 54 receives heat from the defrosting heater 10 through the metal roof 22 to which it is in contact. Furthermore, the heat received by the heat receiving portion 54 is thermally conducted through the bypass portion 56 to the heat dissipation portion 58 extending downward. As a result, heat is supplied from the heat dissipation portion 58 to the frost and water in the receiving tray 30 and the drain pipe 40. As a result, the frost in the receiving tray 30 and the drain pipe 40 can be melted and removed through the drain pipe 40.

As described above, by using the defrosting member 50 in addition to the roof portion 22, heat from the defrosting heater 10 can be effectively supplied to the frost and water in the tray 30 and drain pipe 40 at low manufacturing costs.

Furthermore, as shown by arrows A and B in FIG. 9, the defrosting member 50 can be rotated and positioned so that it fits along the surface of the roof portion 22. Therefore, when installing the defrosting device 2 inside the refrigerator 100, removing it, replacing parts, etc., the defrosting member 50 can be positioned along the surface of the roof portion 22 and secured with tape or the like to prevent the defrosting member 50 from interfering with other components, improving the efficiency of the work.

(refrigerator)
The refrigerator 100 equipped with the defrosting device 2 according to the above embodiment as shown in FIG. 1 can also achieve any of the above-mentioned operational effects.

Although the embodiments and modes of implementation of the present invention have been described, the disclosed contents may vary in the details of the configuration, and the combination and order of elements in the embodiments and modes of implementation may be changed without departing from the scope and concept of the claimed invention.

2 Defrosting device 10 Defrosting heater 12 Glass tube 14 Cap portion 20 Heater cover 22 Roof portion 22A First region 22B Second region 22C Third region 22D Fourth region 24 Bracket 26 Hole portion 30 Receiving tray 30A Bottom portion 30B Side wall portion 32 Opening 40 Drain pipe 50 Defrosting member 52 Hook portion 54 Heat receiving portion 56 Bypass portion 58 Heat dissipation portion 100 Refrigerator 102A Freezer compartment 102B Refrigerating compartments 104A, B Inlet flow path 106 Partition plate 106A Air outlet 110 Evaporator 120 Compressor 130 Fan 140 Damper 150 Drain pipe 160 Evaporation tray G Approximately center VL of glass tube Perpendicular line S Predetermined range

Claims (5)

A defrosting heater having a heating element in a single glass tube having a circular cross section perpendicular to the longitudinal direction;
a roof portion disposed above the glass tube, extending along the longitudinal direction of the glass tube, and formed by forming a metal thin plate into an upwardly convex shape;
a tray disposed below the glass tube, extending along the longitudinal direction of the glass tube, and having an opening at the bottom;
a drain pipe extending downward from the opening;
A defrosting member made of a bent metal rod;
Equipped with
The defrosting member is
A hook portion is formed on one end of the metal bar and is rotatably inserted into a hole provided in the roof portion;
a heat receiving portion connected to the hook portion and extending obliquely downward while contacting the roof portion;
a bypass portion connected to the heat receiving portion and bent to bypass the glass tube;
a heat dissipation portion connected to the bypass portion and extending downward into the inside of the tray and the inside of the drain pipe;
A defrosting device comprising: The defrosting device according to claim 1, characterized in that the defrosting member, which is rotatably attached to the roof by the hook portion, is suspended by gravity, and the heat receiving portion extends obliquely downward while in contact with the roof portion. In a cross section perpendicular to the longitudinal direction of the glass tube,
the roof portion has a top located on a vertical line passing through approximately the center of the glass tube,
3. The defrosting device according to claim 1, wherein the opening is located directly below the glass tube. A refrigerator equipped with a defrosting device according to any one of claims 1 to 3. In order to prevent interference with other components when installing or removing the defrosting device,
5. The refrigerator according to claim 4, wherein the defrosting member is rotated around the hook and disposed along the surface of the roof portion.

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