JP2021076307A - Defrosting device and refrigerator with defrosting device - Google Patents

Abstract

To provide a defrosting device capable of being manufactured at low cost and having sufficient defrosting performance, and a refrigerator with the defrosting device.SOLUTION: Provided are a defrosting device 2 configured so that in a cross section orthogonal to a longitudinal direction of a glass pipe 12, roof parts 22A, B are located on a vertical line VL in which a top part P passes through a substantially center G of the glass pipe 12; within at least a predetermined range S on both sides of the vertical line VL, the roof parts are symmetrical with respect to the vertical line VL; in a cross section along the longitudinal direction of the glass pipe 12 including the vertical line VL, the roof parts 22A, B are formed so that end part regions on both sides in the longitudinal direction are inclined downward so as to reflect radiant heat from the lower side downward; and an opening 32 is located directly below the glass pipe 12, and a refrigerator comprising the defrosting device 2.SELECTED DRAWING: Figure 5

Description

The present invention relates to a defrosting device for defrosting an evaporator of a refrigerator and a refrigerator equipped with this defrosting device.

In order to remove the frost attached to the evaporator, a refrigerator equipped with a defrosting device having a glass tube heater under the evaporator is widely used. In such a refrigerator, the outer surface temperature of the glass tube heater needs to be sufficiently lower than the combustible temperature of the solvent flowing in the evaporator. However, if the power input to the glass tube heater is suppressed 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 in the upper evaporator melts due to natural convection heat transfer by the glass tube heater, the water that has melted down from the evaporator may refreeze in the saucer located below the glass tube heater. is there.

In order to deal with this, a defrosting device using a defrosting heater having a heating element in a double glass tube has been proposed (see, for example, Patent Document 1). In the defrosting device described in Patent Document 1, by using a double glass tube, although the outer surface temperature of the glass tube heater is low, a sufficient amount of heat can be added to melt the frost re-frozen in the saucer. it can.

Japanese Unexamined Patent Publication No. 2004-198097

However, the glass tube heater provided with the double glass tube has a problem that the manufacturing cost is high, and the manufacturing cost of the defrosting device provided with the glass tube heater and the refrigerator provided with the defrosting device is high.

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

The defrosting device of the present invention
A defrosting heater having a heating element in a single glass tube having a circular cross section orthogonal to the longitudinal direction,
A roof portion that is arranged above the glass tube, extends along the longitudinal direction of the glass tube, and forms a thin metal plate in an upward convex shape.
A saucer that is placed below the glass tube and extends along the longitudinal direction of the glass tube to form an opening at the bottom.
A drain pipe extending downward from the opening,
With
In a cross section orthogonal to the longitudinal direction of the glass tube
The roof is symmetrical with respect to the perpendicular, with the top located above a perpendicular passing substantially the center of the glass tube and within at least a predetermined range on both sides of the perpendicular.
In the cross section along the longitudinal direction of the glass tube including the vertical line,
The roof portion is formed so that the end regions on both sides in the longitudinal direction are inclined downward so as to reflect the radiant heat from the lower side downward.
The opening is characterized in that it 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. In order to lower the outer surface temperature of the glass tube, even if the power input to the defrost heater is suppressed, the roof reflects the radiant heat from the defrost heater to the saucer side and melts the refrozen frost in the saucer. can do. In particular, in the cross section orthogonal 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 substantially center of the glass tube. .. Further, in the cross section along the longitudinal direction of the glass tube including the above-mentioned perpendicular line, the upward convex shape of the roof portion is inclined so as to reflect the radiant heat from the lower side downward in the end regions on both sides. It is formed. That is, the roof portion is formed in a shape with enhanced reflection on all sides. As a result, radiant heat with little variation or bias can be incident on the main part of the saucer except directly under the glass tube.

Further, since the opening of the saucer is located directly below the glass tube, the radiant heat from the defrosting heater is directly incident on the opening and its surroundings. As a result, the frost re-frozen in the saucer can be melted and 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.

In addition, the present invention
In the height direction, the position of the lower end of the roof is the same as or above the position of the upper end of the glass tube.
In the height direction, the position of the top of the roof is the same as or lower than the position of the upper end of the glass tube plus a length corresponding to 1.5 times the outer diameter of the glass tube. It is characterized by being done.

According to the present invention, the position of the lower end of the roof is the same as or higher than the position of the upper end of the glass tube, so that heat transfer by natural convection causes frost on the upper evaporator. It can be surely melted. Further, in the height direction, the position of the top of the roof is the same as or lower than the position of the upper end of the glass tube plus a length corresponding to 1.5 times the outer diameter of the glass tube. Since it is arranged in, the glass tube can be arranged near the evaporator to enhance the effect of melting the frost attached to the evaporator. At the same time, since the top of the roof is not too far from the saucer, the radiant heat from the defrosting heater is strongly reflected by the roof toward the saucer, and the effect of melting the frost in the saucer can be enhanced.
By arranging the roof portion as described above, the frost on the evaporator and the saucer can be effectively melted, and high defrosting performance can be exhibited.

In addition, the present invention
In a cross section orthogonal to the longitudinal direction of the glass tube, the width dimension at the lower end of the roof portion is within a range of 2 times or more and 3 times or less the outer diameter of the glass tube.

By setting the width dimension at the lower end of the roof portion within the range of 2 times or more and 3 times or less the outer diameter of the glass tube, the frosts of both the evaporator and the saucer can be effectively melted in a well-balanced manner.

In addition, the present invention
Further equipped with a defrosting member made of bent metal rods,
The defrosting member
A hook portion formed at one end of the metal rod and rotatably inserted into a hole provided in the roof portion.
A heat receiving part that is connected to the hook part and extends diagonally downward while being in contact with the roof part.
A bypass portion connected to the heat receiving portion and bent so as to bypass the glass tube, and a bypass portion.
A heat radiating portion that is connected to the detour portion and extends downward toward the inside of the saucer and the inside of the drain pipe.
It is characterized by having.

According to the present invention, the defrosting member rotatably attached to the roof portion by the hook portion is arranged so that the heat receiving portion is in contact with the roof portion by gravity, and the defrosting member is removed from the defrosting heater via the metal roof. Can receive heat. Further, the detour portion allows the heat radiating portion to be arranged inside the saucer and the inside of the drain pipe by gravity without interfering with the glass tube. The heat received in the roof portion is electrically conducted to the heat radiating portion extending downward through the bypass portion, and the heat can be supplied from the radiating portion to the frost and water in the saucer and the drain pipe.
As described above, by using the defrosting member, it is possible to manufacture at a low manufacturing cost, and it is possible to effectively supply the heat from the defrosting heater to the frost and water in the saucer and the drain pipe.

Moreover, the refrigerator of the present invention
It is characterized by being provided with the above-mentioned defrosting device.

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

As described above, in the present invention, it is possible 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.

It is a side sectional view which shows typically an example of the refrigerator equipped with the defrosting apparatus which concerns on embodiment of this invention. It is a perspective view which shows typically the outline of the defrosting apparatus which concerns on 1st Embodiment of this invention. It is a figure which shows the cross section orthogonal to the longitudinal direction of the glass tube seen from the X-axis direction of FIG. 2, and is the side sectional view which shows typically the defrosting apparatus which concerns on 1st Embodiment of this invention. It is a figure which shows the cross section along the longitudinal direction of a glass tube including the vertical line which passes through the substantially center of the circular outer shape of a glass tube, and is the side sectional view which shows typically the defrosting apparatus which concerns on 1st Embodiment of this invention. Is. It is a figure which shows the cross section orthogonal to the longitudinal direction of the glass tube seen from the X-axis direction of FIG. 2, and is the side sectional view for demonstrating the arrangement of the roof part which concerns on embodiment of this invention. It is a figure which shows the cross section orthogonal to the longitudinal direction of the glass tube seen from the X-axis direction of FIG. 2, and is the side sectional view which shows typically the defrosting apparatus which concerns on 2nd Embodiment of this invention. It is a figure which shows the cross section orthogonal to the longitudinal direction of the glass tube seen from the X-axis direction of FIG. 2, and is the side sectional view which shows typically the defrosting apparatus which concerns on 3rd Embodiment of this invention. It is a figure which shows the cross section orthogonal to the longitudinal direction of the glass tube seen from the X-axis direction of FIG. 2, and is the side sectional view which shows typically the defrosting apparatus which concerns on 4th Embodiment of this invention. It is a perspective view for demonstrating the defrosting member which concerns on embodiment of this invention.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. The defrosting device described below is for embodying the technical idea of the present invention, and the present invention is not limited to the following unless otherwise specified.
In each drawing, members having the same function may be designated by the same reference numerals. In consideration of the explanation of the main points or the ease of understanding, the configurations may be divided into embodiments and examples for convenience, but the configurations shown in different embodiments can be partially replaced or combined. In the embodiment described later, the description of the matters common to the above will be omitted, and only the differences will be described. In particular, similar actions and effects with the same configuration will not be mentioned sequentially for each embodiment or embodiment. The size and positional relationship of the members shown in each drawing may be exaggerated for the sake of clarity. In the following description and drawings, the X-axis, Y-axis, and Z-axis are shown assuming that they are arranged in the refrigerator installed on the floor. The vertical direction is indicated by the Z axis, and the longitudinal direction of the glass tube 12 constituting the defrost heater 10 described later is indicated by the X axis.

(Refrigerator equipped with the defrosting device of the present invention)
FIG. 1 is a side sectional view schematically showing an example of a refrigerator 100 provided with a defrosting device 2 according to an embodiment of the present invention. The refrigerator 100 shown in FIG. 1 includes a freezing chamber 102A and a refrigerating chamber 102B. On the back side of the freezing chamber 102A and the refrigerating chamber 102B, inlet-side flow paths 104A and B partitioned by a partition plate 106 are provided. An evaporator 110 is arranged in the inlet side flow path 104A on the freezing chamber 102A side, and a fan 130 is arranged above the evaporator 110. Below the evaporator 110, the defrosting device 2 according to each of the embodiments described below is arranged.

A compressor 120 communicating with the evaporator 110 is arranged in an external machine room on the back side of the freezing chamber 102A. The refrigerant (gas) compressed by the compressor 120 is liquefied by the condenser, the liquefied refrigerant takes heat of the gas in the refrigerator by the evaporator 110 and vaporizes, and the vaporized refrigerant is compressed again by the compressor 120. Repeat the cycle of A damper 140 is arranged between the entry side flow path 104A on the freezing chamber 102A side and the entry side flow path 104B on the refrigerating chamber 102B side. FIG. 1 shows a state in which the damper 140 is closed.

As shown by the dotted arrow in FIG. 1, when the compressor 120 and the fan 130 are driven in the state where the damper 140 is closed, the gas in the freezing chamber 102A flows, and the cold air that has passed through the evaporator 110 is the partition plate 106. It flows into the freezing chamber 102A from the air outlet 106A provided in the freezing chamber 102A. The inflowing gas circulates in the freezer chamber 102A and returns to the lower side of the evaporator 110 in the inlet side flow path 104A again. The inside of the freezing chamber 102A can be cooled by the circulation of the gas cooled through the evaporator 110. When the damper 140 is open, cold air also circulates on the refrigerating chamber 102B side.

Moisture contained in the cooling air condenses and frost adheres to the surface of the heat exchange tube of the evaporator 110. If a large amount of frost adheres to the heat exchange tube, the cooling performance deteriorates, so that it is necessary to defrost the evaporator 110 on a regular basis. Therefore, the defrosting device 2 is arranged 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 operating, the heat exchange tube can be warmed to perform defrosting. The water from which the frost of the evaporator 110 has melted down flows from the drain pipe 40 of the defrosting device 2 through the drain pipe 150 of the refrigerator 100 and is discharged to the evaporating dish 160 arranged in the machine room.

(Defrosting device according to the first embodiment)
FIG. 2 is a perspective view schematically showing an outline of the defrosting device 2 according to the first embodiment of the present invention. FIG. 3 is a view showing a cross section orthogonal to the longitudinal direction of the glass tube 12 seen from the X-axis direction of FIG. 2, and is a side cross section schematically showing the defrosting device 2 according to the first embodiment of the present invention. It is a figure. FIG. 4 is a view showing a cross section along the longitudinal direction of the glass tube including a perpendicular line passing through the substantially center of the circular outer shape of the glass tube, and schematically shows the defrosting device according to the first embodiment of the present invention. It is a side sectional view which shows. In FIG. 4, the description of the saucer is omitted. Next, the defrosting device 2 according to the first embodiment of the present invention will be described with reference to FIGS. 2 to 4.

The defrosting device 2 according to the present embodiment includes a defrosting heater 10 having a heating element in a single quartz glass tube 12. Further, the defrosting device 2 includes a heater cover 20 arranged above the glass tube 12 and having a roof portion 22 in which a thin metal plate is formed in an upward convex shape extending along the longitudinal direction of the glass tube 12. .. Further, the defrosting device 2 is arranged below the glass tube 12, and has a saucer 30 extending along the longitudinal direction of the glass tube 12 and a drain tube 40 extending downward from an opening 32 provided at the bottom of the saucer 30. Be prepared. In FIG. 3, the drain pipe 40 shown in FIG. 2 is schematically shown.

Further, the defrosting device 2 according to the present embodiment includes a defrosting member 50 made of a bent metal rod. The defrosting member 50 has a hook portion 52 formed at one end of a metal rod and rotatably inserted into a hole portion 26 provided in a thin metal plate constituting the roof portion 22, and a hook portion 52. The heat receiving portion 54, which is connected and extends diagonally downward while being in contact with the thin metal plate constituting the roof portion 22, and the bypass portion 56, which is connected to the heat receiving portion 54 and bent so as to bypass the glass tube 12, and the bypass portion 56. It is provided with a heat radiating portion 58 that is connected and extends downward toward the inside of the saucer 30 and the inside of the drain pipe 40.

<Defrost heater>
The glass tube 12 constituting the defrosting heater 10 according to the present embodiment has an elongated cylindrical shape. Inside the glass tube 12, a heating element made of a metal wire such as a nichrome wire is arranged. In the heat generating region in the center of the glass tube 12, a coiled heater in which a metal wire is wound in a coil shape is arranged, and the metal wire extends outward from both ends thereof. Both ends of the glass tube 12 are covered with cap portions 14 made of a material having excellent heat resistance and electrical insulation such as silicon rubber. The metal wires extending from both sides of the coiled heater extend to the outside of the glass tube 12 via the cap portion 14 and are electrically connected to the external cable.

In order to comply with the IEC standard, the input power is controlled so that the outer surface temperature of the glass tube 12 at the time of heat generation becomes 360 ° C. or lower. The point that practically sufficient defrosting can be performed on the evaporator 110 even with such control of the input power will be described in detail later.

<Heater cover>
The heater cover 20 includes a roof portion 22 extending along the longitudinal direction of the glass tube 12 and having a thin metal plate formed in an upward convex shape, and brackets 24 provided on both sides of the roof portion 22 in the longitudinal direction. Cap portions 14 at both ends of the glass tube 12 are inserted into a substantially C-shaped opening provided in the bracket 24, and a heater cover 20 is attached to the defrost heater 10.
As the metal thin plate constituting the roof portion 22, an aluminum thin plate having high reflectance and high thermal conductivity is used in this embodiment. However, the present invention is not limited to this, and any other metal sheet such as copper can be used. A thin aluminum plate can be bent to form a convex shape, or two thin aluminum plates can be joined together to form a convex shape.

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

Further, as shown in FIG. 4, in the cross section of the glass tube 12 along the longitudinal direction, the roof portion 22 reflects the radiant heat from the lower side downward at the end regions on both sides in the longitudinal direction thereof. It has a third region 22C and a fourth region 22D that are inclined downwards. That is, as shown in FIG. 2, the roof portion 22 has a structure like a hipped roof composed of four thin plate-like members in the first to fourth regions 22A to 22D, and reflects on all sides. It is formed in a raised shape. The reflective surfaces of the third region 22C and the fourth region 22D may be formed of a flat surface or a smoothly curved curved surface.
With the above configuration, the radiant heat from the defrosting heater 10 can be reflected downward and incident on the main part of the lower tray 30. As a result, the frost re-frozen in the saucer 30 can be thawed.

<Sink and drain pipe>
The saucer 30 extends along the longitudinal direction of the glass tube 12 and has a bottom portion 30A and a side wall portion 30B surrounding the bottom portion 30A, and the upper portion is open. An opening 32 is provided at a position substantially central in the longitudinal direction of the bottom portion 30A of the saucer 30. The bottom portion 30A of the saucer 30 is inclined so that the opening 32 has the lowest height. As a result, the water that has fallen from the upper evaporator 110 flows through the bottom portion 30A of the saucer 30 and flows into the opening 32. A drain pipe 40 is attached to the opening 32 provided in the bottom portion 30A of the saucer 30, and the drain pipe 40 extends downward from the opening 32.

The opening 32 of the saucer 30 is located directly below the glass tube 12 in a cross section orthogonal to the longitudinal direction of the glass tube 12 when viewed from the X-axis direction. With such an arrangement, the opening 32 and the surrounding area can receive radiant heat directly from the defrosting heater 10 and can thaw the frost re-frozen in the saucer 30.
The saucer 30 is preferably formed of a metal material having a high thermal conductivity such as aluminum. Considering the ease of attachment of the defrosting device 2 to the refrigerator 100 and the like, the drain pipe 40 is preferably formed of an elastic resin material or the like.

(Arrangement of roof)
FIG. 5 is a view showing a cross section orthogonal to the longitudinal direction of the glass tube seen from the X-axis direction of FIG. 2, and is a side sectional view for explaining the arrangement of the roof portion 22 according to the embodiment of the present invention. is there. In FIGS. 5 and 6 to 8, which will be described later, the radiant heat generated from the defrost heater 10 is indicated by a dotted arrow, and the upward flow of the surrounding gas warmed by the defrost heater 10 due to natural convection is shown by a chain line. It is indicated by an arrow. In FIG. 5, the defrosting device according to the first embodiment shown in FIG. 3 will be described as an example, but also in the defrosting device according to the second to fourth embodiments described later with reference to FIGS. 6 to 8, the roof The functions of the unit 22 are basically the same.

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

The predetermined range S is preferably defined corresponding to the width dimension of the saucer 30 orthogonal to the longitudinal direction seen from the X-axis direction. When both ends of the saucer 30 in the width direction are located equidistant from the vertical line VL, the upward convex shape of the roof portion 22 is symmetrical with respect to the vertical line VL to the extent that the reflected light reaches both ends of the saucer 30. It is preferably shaped. When the distances from the perpendicular lines VL at both ends in the width direction of the saucer 30 are different, the upward convex shape of the roof portion 22 with respect to the perpendicular lines VL is at least within the range where the reflected light reaches the end near the perpendicular line VL. It is preferable that the shape is symmetrical. As a result, the frost in the saucer 30 can be efficiently melted by injecting radiant heat with little variation or bias into the main part of the saucer 30.

In the cross section orthogonal to the longitudinal direction of the glass tube 12 seen from the X-axis direction, the first region 22A and the second region 22B are shown as two sides connected by a top P located on the perpendicular line VL. The angle θ formed by the first region 22A and the perpendicular line VL and the angle θ formed by the second region 22B and the perpendicular line VL are substantially the same. Further, in the example shown in FIG. 5, the lengths of the first region 22A and the second region 22B are also the same.

This means that in a cross section orthogonal to the longitudinal direction of the glass tube 12 seen from the X-axis direction, the first region 22A and the second region 22B are isosceles triangles whose vertices are points P located on the perpendicular VL. It can also be said that it constitutes the two equilateral sides of.

As shown by the alternate long and short dash line in FIG. 5, when the first region 22A and the second region 22B are extended diagonally downward, they intersect with the horizontal line extending the bottom surface of the saucer 30. This forms the upper half of the parallelogram. Then, the center of the opening 32 of the saucer 30 substantially coincides with the position of the perpendicular line VL. That is, the opening 32 of the saucer 30 is located at the center position of the upward convex roof portion 22 and the parallelogram having its extension line as two sides.

With such an arrangement, the radiant heat emitted upward from the defrost heater 10 is reflected downward by the roof portion 22, and the radiant heat with little variation or bias is reflected in the main part of the saucer 30 except directly under the glass tube 12. Can be incident. Immediately below the glass tube 12, there is a region where the reflected light from the roof portion 22 does not reach, and in such a region, the radiant heat emitted downward from the defrost heater 10 is directly incident. As a result, the re-frozen frost can be efficiently melted in the main part on the saucer 30. 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 to the evaporating dish 160 arranged in the machine room.

In the example shown in FIG. 5, in the height direction (Z-axis direction), the position H1 of the lower end portion of the roof portion 22 is arranged above the position H0 of the upper end portion of the glass tube 12. However, the present invention is not limited to this, and the position H1 at the lower end of the roof portion 22 may be arranged at the same position as the position H0 at the upper end of the glass tube 12. That is, in the height direction (Z-axis direction), the position H1 of the lower end portion of the roof portion 22 is arranged at the same level as or above the position H0 of the upper end portion of the glass tube 12.
With such a setting, the gas around the glass tube 12 warmed by the defrosting heater 10 can be efficiently flowed upward by natural convection. As a result, heat can be supplied to the evaporator 110 by natural convection heat transfer, so that the frost attached to the evaporator 110 can be reliably melted.

Further, in the height direction (Z-axis direction), the position H2 of the top P of the roof portion 22 adds a length corresponding 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. It is located at the same position as or below the position. With such a setting, the defrosting heater 10 can be arranged relatively close to the evaporator 110, so that the effect of melting the frost attached to the evaporator 110 can be enhanced. At the same time, since the top P of the roof portion 22 is not significantly separated from the saucer 30, the radiant heat from the defrost heater 10 is strongly reflected by the roof portion 22 toward the saucer 30 to enhance the effect of melting the frost in the saucer 30. be able to.
By arranging the roof portion 22 as described above, the frost on the evaporator 110 and the saucer 30 can be effectively melted, and high defrosting performance can be exhibited.

Further, in the present embodiment, the width dimension W at the lower end of the roof portion 22 is twice or more and three times or less the outer diameter D of the glass tube in the cross section orthogonal to the longitudinal direction of the glass tube 12 seen from the X-axis direction. It is within the range. Further, if the distance between the end portion of the lower end of the roof portion 22 in the width direction and the outer shape of the glass tube 12 is M, there is a relationship of 0.5D <= M <= D.

If the width dimension W at the lower end of the roof portion 22 is not so large compared to 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, when the width dimension W at the lower 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 2 times or more and 3 times or less the outer diameter of the glass tube 12, the frosts of both the evaporator 110 and the saucer 30 are effectively balanced. Can be dissolved in.
A similar relationship is shown in a cross section orthogonal to the longitudinal direction of the glass tube 12 viewed from a direction 180 degrees opposite to the X-axis direction.

(Defrosting device according to the second embodiment)
FIG. 6 is a cross-sectional view showing a cross section orthogonal to the longitudinal direction of the glass tube seen from the X-axis direction of FIG. 2, and is a side cross-sectional view schematically showing a defrosting device according to a second embodiment of the present invention. is there.
Also in the defrosting device 2 according to the second embodiment, the roof portion 22 has an upward convex shape in which two flat plate-shaped first regions 22A and second regions 22B are connected. However, in the cross section orthogonal to the longitudinal direction of the glass tube 12 seen from the X-axis direction, the length of the second region 22B is the same as that of the first embodiment, but the length of the first region 22A is , Longer than the first embodiment.

As shown in FIG. 6, in a cross section orthogonal to the longitudinal direction of the glass tube 12 seen from the X-axis direction, the upward convex shape of the roof portion 22 is formed on both sides of a perpendicular line passing through the substantially center G of the circular outer shape of the glass tube 12. Within the fixed range S, it is symmetric with respect to the perpendicular VL, but not symmetric with respect to the perpendicular VL in all regions. In one first region 22A of the roof portion 22, the width T is extended.

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

(Defrosting device according to the third embodiment)
FIG. 7 is a view showing a cross section orthogonal to the longitudinal direction of the glass tube 12 seen from the X-axis direction of FIG. 2, and is a side cross section schematically showing the defrosting device 2 according to the third embodiment of the present invention. It is a figure.
In the defrosting device according to the first and second embodiments, the roof portion 22 is composed of two flat plate-shaped first regions 22A and a second region 22B, but in the third embodiment, , The roof portion 22 is composed of a smooth curved curved surface.

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

(Defrosting device according to the fourth embodiment)
FIG. 8 is a view showing a cross section orthogonal to the longitudinal direction of the glass tube 12 seen from the X-axis direction of FIG. 2, and is a side cross section schematically showing the defrosting device 2 according to the fourth embodiment of the present invention. It is a figure.
Also in the fourth embodiment, the roof portion 22 is formed of a smooth curved curved surface. In the cross section orthogonal to the longitudinal direction of the glass tube 12 seen from the X-axis direction, the upward convex shape of the roof portion 22 is within a fixed range S on both sides of the perpendicular line passing through the substantially center G of the circular outer shape of the glass tube 12. Although it is symmetrical with respect to the perpendicular VL, the roof portion 22 is not symmetrical with respect to the perpendicular VL in all areas. In one first region 22A of the roof portion 22, the width T is extended.

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

As described above, in any of the defrosting devices 2 according to the first to fourth embodiments of the present invention, defrosting having a heating element in a single glass tube 12 having a circular cross section perpendicular to the longitudinal direction. The heater 10 and the roof portion 22 which is arranged above the glass tube 12 and extends along the longitudinal direction of the glass tube 12 and is formed by forming a thin metal plate in an upward convex shape, and is arranged below the glass tube 12. A saucer 30 extending along the longitudinal direction of the glass tube 12 and having an opening 32 formed at the bottom, and a drain tube 40 extending downward from the opening 32 are provided, and the roof is provided in a cross section orthogonal to the longitudinal direction of the glass tube 12. The portion 22 has a top P located on a vertical line VL passing through the substantially center G of the glass tube 12, is symmetrical with respect to the vertical line VL, and includes the vertical line VL, at least within a predetermined range on both sides of the vertical line VL. In the cross section along the longitudinal direction of the glass tube 12, the roof portion 22 is formed so that the end regions on both sides in the longitudinal direction are inclined downward so as to reflect the radiated heat from the lower side, and the opening 32 is formed. Is located directly below the glass tube 12.

By using the 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 in order to lower the outer surface temperature of the glass tube 12, the roof portion 22 reflects the radiant heat from the defrost heater 10 to the saucer side 30, and the inside of the saucer 30. Can dissolve frost. In particular, the upward convex shape of the roof portion 22 is symmetrical with respect to the perpendicular line VL in at least a predetermined range S on both sides of the perpendicular line VL passing through the substantially center G of the glass tube 12, and is in the longitudinal direction of the glass tube 12 ( In 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 radiated heat from the lower side downward, and the opening 32 of the saucer 30 is glass. It is located directly below the tube 12. As a result, the reflected heat from the roof portion 22 and the radiant heat directly received from the defrosting heater 10 can cause the radiant heat with little variation or bias to be incident on the main portion of the saucer 30.

Therefore, the frost attached to the evaporator 110 can be melted and discharged through the opening 32 of the saucer 30 and the drain pipe 40. As described above, it is possible to provide the defrosting device 2 which can be manufactured at low cost and has sufficient defrosting performance.

Further, according to the defrosting device 2 according to the first to fourth embodiments, the position H1 of the lower end portion of the roof portion 22 is the same as the position H0 of the upper end portion of the glass tube 12 in the height direction (Z-axis direction). Or because it is located above it, the frost on the evaporator 110 can be effectively melted by natural convection heat transfer. Further, in the height direction (Z-axis direction), the position H2 of the top P of the roof portion 22 adds a length corresponding 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. Since it is arranged at the same position as or below the position, the effect of melting the frost attached to the evaporator 110 can be enhanced, and the effect of melting the frost in the saucer 30 can be enhanced.
By arranging the roof portion 22 as described above, the frost on the evaporator 110 and the saucer 30 can be effectively melted, and high defrosting performance can be exhibited.

Further, according to the defrosting device 2 according to the first to fourth embodiments, the width dimension W at the lower end of the roof portion 22 is within a range of 2 times or more and 3 times or less the outer diameter D of the glass tube 12. , Both the evaporator 110 and the saucer 30 can effectively melt the frost in a well-balanced manner.

(Defrosting member)
FIG. 9 is a perspective view for explaining the defrosting member according to the embodiment of the present invention. In FIG. 9, the shape of the roof portion 22 is simply shown.
Each of the defrosting devices 2 according to the above embodiment includes a defrosting member 50 made of a bent metal rod. As shown in FIG. 3 or 9, the defrosting member 50 is formed at one end of a metal rod and is rotatably inserted into a hole 26 provided in a thin metal plate constituting the roof portion 22. Has a hook portion 52. Further, the defrosting member 50 has a heat receiving portion 54 that is connected to the hook portion 52 and extends diagonally downward while being in contact with the metal thin plate constituting the roof portion 22. The defrosting member 50 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 is obliquely in contact with the thin metal plate constituting the roof portion 22. It extends downward.

Further, the defrosting member 50 has a bypass portion 56 that is connected to the heat receiving portion 54 and is bent so as to bypass the glass tube 12. Since the heat receiving portion 54 is in contact with the thin metal plate constituting the roof portion 22 and the position is fixed by gravity, the detour portion 56 can be surely kept at a position separated from the glass tube 12. Further, the defrosting member 50 has a heat radiating portion 58 which is connected to the bypass portion 56 and extends downward toward the inside of the saucer 30 and the inside of the drain pipe 40. The defrosting member 50 is terminated at the end of the heat radiating portion 58.

In the defrosting member 50 rotatably attached to the roof portion 22 by the hook portion 52, the heat receiving portion 54 comes into contact with the roof portion 22 due to gravity. , Receives heat from the defrost heater 10. Further, the heat received by the heat receiving portion 54 is conducted to the heat radiating portion 58 extending downward through the bypass portion 56. As a result, heat is supplied from the heat radiating unit 58 to the frost and water in the saucer 30 and the drain pipe 40. As a result, the frost in the saucer 30 and the drain pipe 40 can be melted and removed via the drain pipe 40.

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

Further, as shown by arrows A and B in FIG. 9, the defrosting member 50 can be rotated and arranged along the surface of the roof portion 22. Therefore, when the defrosting device 2 is installed in the refrigerator 100, or when it is removed or parts are replaced, the defrosting member 50 is attached along the surface of the roof portion 22 and fastened with tape or the like, so that the defrosting member 50 can be replaced. Work efficiency can be improved by preventing interference with the members of the above.

(refrigerator)
A refrigerator 100 provided with the defrosting device 2 according to the above embodiment as shown in FIG. 1 can also exert any of the above-mentioned effects.

Although the embodiments and embodiments of the present invention have been described, the disclosed contents may be changed in the details of the configuration, and the invention in which the embodiments and the combinations and orders of the elements in the embodiments are changed are requested. It can be realized without departing from the scope and ideas of.

2 Defrosting device 10 Defrosting heater 12 Glass tube 14 Cap part 20 Heater cover 22 Roof part 22A First area 22B Second area 22C Third area 22D Fourth area 24 Bracket 26 Hole part 30 Evaporating dish 30A Bottom part 30B Side wall part 32 Opening 40 Drain pipe 50 Defrosting member 52 Hook part 54 Heat receiving part 56 Detour part 58 Heat dissipation part 100 Refrigerator 102A Refrigerator room 102B Refrigerator room 104A, B Input side flow path 106 Partition plate 106A Air outlet 110 Evaporating dish 120 Compressor 130 Fan 140 Damper 150 Drain pipe 160 Evaporating dish G Approximate center of glass tube VL Vertical line S Predetermined range

Claims (5)

A defrosting heater having a heating element in a single glass tube having a circular cross section orthogonal to the longitudinal direction,
A roof portion that is arranged above the glass tube, extends along the longitudinal direction of the glass tube, and forms a thin metal plate in an upward convex shape.
A saucer that is placed below the glass tube and extends along the longitudinal direction of the glass tube to form an opening at the bottom.
A drain pipe extending downward from the opening,
With
In a cross section orthogonal to the longitudinal direction of the glass tube
The roof is symmetrical with respect to the perpendicular, with the top located above a perpendicular passing substantially the center of the glass tube and within at least a predetermined range on both sides of the perpendicular.
In the cross section along the longitudinal direction of the glass tube including the vertical line,
The roof portion is formed so that the end regions on both sides in the longitudinal direction are inclined downward so as to reflect the radiant heat from the lower side downward.
The defrosting device is characterized in that the opening is located directly below the glass tube.
In the height direction, the position of the lower end of the roof is the same as or above the position of the upper end of the glass tube.
In the height direction, the position of the top of the roof is the same as or lower than the position of the upper end of the glass tube plus a length corresponding to 1.5 times the outer diameter of the glass tube. The defrosting device according to claim 1, wherein the defrosting device is provided.
According to claim 1 or 2, the width dimension at the lower end of the roof portion is within a range of 2 times or more and 3 times or less the outer diameter of the glass tube in a cross section orthogonal to the longitudinal direction of the glass tube. The defroster described.
Further equipped with a defrosting member made of bent metal rods,
The defrosting member
A hook portion formed at one end of the metal rod and rotatably inserted into a hole provided in the roof portion.
A heat receiving part that is connected to the hook part and extends diagonally downward while being in contact with the roof part.
A bypass portion connected to the heat receiving portion and bent so as to bypass the glass tube, and a bypass portion.
A heat radiating portion that is connected to the detour portion and extends downward toward the inside of the saucer and the inside of the drain pipe.
The defrosting device according to any one of claims 1 to 3, wherein the defrosting device is characterized by having.
A refrigerator provided with the defrosting device according to any one of claims 1 to 4.

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