KR20000050531A - Microwave oven - Google Patents

Abstract

PURPOSE: A microwave oven having a heater with an enhanced structure of opened surface thereof and a glass door with an enhanced structure is provided in which a glass cover arranged at an inner surface of the cavity of the oven has a porous sheet layer formed integrally with the glass cover and the glass door includes a metalized porous sheet layer, to thereby achieve a simplified structure and enhanced shielding effect and heat transmission efficiency. CONSTITUTION: A structure of opened surface of a heater of a microwave oven in which the microwave oven includes a heater(6) at an outer wall surface of a cavity(1), an opened portion at a contact surface between the heater(6) and the cavity(1), and a heat transmission and electromagnetic wave shielding unit consisting of a porous plate and a glass cover(10), the structure comprising the glass cover(10) being supported from a center of the opened portion at a contact surface between the heater(6) and the cavity(1), the glass cover including at a surface thereof a porous sheet layer(20).

Description

Heater opening structure and door glass structure of microwave oven {Microwave oven}

The present invention relates to a microwave oven, and more particularly, in order to solve the problem of performance or workability of the perforated plate installed in the form of covering the opening for heat transfer and electromagnetic shielding, unifying the perforated plate into a glass without an independent structure. The present invention relates to an opening surface structure of a microwave oven and a door glass which have been changed into a layered structure.

The microwave oven includes a cavity 1, which has been emptied into a space for food, as shown in FIG. 1.2, a tray 2 within the cavity 1, a movable turntable, its driving unit 14, and a door that covers or opens the tray 2; ), A magnetron (4) that makes microwaves around the cavity (1) and sends microwaves into the cavity (1), a waveguide (5) that guides the microwaves into the cavity (1) and the microwaves into the cavity (1) It consists of an aperture formed between the cavity 1 and the waveguide 5 for irradiation.

Unlike microwave ovens using energy sources as microwaves, a microwave oven in which a heater 6 is separately mounted outside the cavity 1 includes a driving unit for irradiating microwaves or moving the tray 2 in the cavity 1. In the basic microwave oven structure of FIG. 2, as shown in FIG. 2, an opening surface 7 is formed on the surface of the cavity 1, and the porous plate 8 and the heater 6, which are perforated by a plurality of dense holes, are formed. Radiator heat of the heater 6 was installed by mounting the heater housing 9 on the outside of the heater 6 and the glass cover 10 on the inner side of the cavity 1 in which the opening surface 7 was processed. It has the characteristic which extended to this cavity 1.

When power is supplied to the magnetron 4, microwaves are generated and irradiated into the cavity 1, and the food heated on the tray 2 is heated by the energy, and the food is heated in the cavity 1 with the aid of the rotation of the turntable. Heated.

Likewise, when power is supplied to the heater 6, radiant heat of the heater 6 is transferred into the cavity 1 through the opening surface 7 and the glass cover 10 to heat food in the cavity 1.

If the heat source to be sent into the cavity (1) is classified, it can be divided into the high frequency energy of the magnetron (4) and the radiant heat of the heater (6), of which the radiant heat of the heater is added to or added to the basic heating type through the high frequency energy source. It is applied to diversify the function of microwave oven.

When the heater 6 is installed on the wall of the cavity 1 as a heat source separate from the high frequency energy, the cavity 1 is located so that the radiant heat from the heater 6 can reach the inside of the cavity 1. The corresponding wall surface of) has a perforated opening surface 7. However, if the opening surface 7 is left as a through hole, the hole becomes a leakage path through which electromagnetic waves are discharged out of the cavity 1, so that the hole is treated with the porous plate 8 to prevent leakage and again the porous plate 8 Inwardly, the glass cover 10 is attached to shield the opening surface 7 so that gas-liquid vapor particles formed in the cavity 1 are transferred to the heater 6 through the porous plate 8 and do not contaminate the heater. The heater 6 is installed in the cavity 1 wall surface.

Therefore, even if the food is placed in the cavity 1 and the food is heated using the microwave as an energy source, contamination of the heater 6 due to steam generated during the heating process is blocked by the shielding structure of the porous plate 8 and at the same time the heater 6 When the power is turned on, the radiant heat of the heater 6 heats the food surface in the cavity 1 via the porous plate 8 and the glass cover 10.

Since the function of the porous plate 8 is to shield electromagnetic leakage in the cavity 1 and to transmit radiant heat of the heater 6 into the cavity 1, as shown in FIG. 3, the thickness and heat conduction of the material of the porous plate 8 are maintained. In addition, the effectiveness of the porous plate 8 varies depending on various factors such as the distance and diameter between the holes 11 and the overall length of the hole array. However, suitable materials include the cavity 1 and the heater 6. Since it is exposed to high temperature / high temperature, it is processed from materials with low heat resistance and low heat deformation, and if the perforated plate 8 is made independently of the cavity 1 and attached to the cavity 1, the yield of the product is lowered. The wall surface of 1) is processed and the porous plate 8 is formed. In this way, the perforated plate 8 can be made into a single process in the press working step of making the cavity 1.

The ideal form of blocking the leakage of electromagnetic waves through the cavity (1) is in the form of a completely sealed film, and the radiation heat from outside the cavity (1) is passed into the cavity (1) as it is to send radiant heat to the destination without loss. 8) can be seen to share the opposite characteristics of the shielding and heat transfer to the last, and the rest is the shielding or heat transfer effect due to the factors of the structure of the hole 11 of the porous plate 8 and the material itself. It is different.

As described above, when the perforated plate 8 is formed in the cavity 1, the yield of the product can be considerably lowered, while the degree of freedom in processing is limited, so that it is difficult to obtain the advanced perforated plate 8 that achieves both an improved shielding effect and a heat transfer effect. However, if the diameter of the hole 11 of the porous plate 8 is reduced, the electromagnetic wave shielding effect is increased, but the heat transfer effect is relatively low. When the function of one side is strengthened and the other function is weakened, the advanced plate structure is developed. no.

However, when the porous plate 8 is formed separately and attached to the cavity 1, the porous plate 8 may be manufactured in an advanced form rather than forming the porous plate 8 directly in the cavity 1. For example, it is possible to arrange and process a variety of holes that share electromagnetic shielding and heat transfer characteristics, or to produce a perforated plate that has evolved from the selection of an appropriate material. There is a downside to the overall disadvantage that there is no comparative advantage.

In general, the electromagnetic shielding effect associated with the arrangement of circular holes is known by the following equation (Quin 1957).

here : Shielding Effect

: Distance between holes

: Diameter of hole

: Length of hole array

: Thickness of perforated plate

The above equation is known to be effective when the diameter of the hole is smaller than λ / 2π. Therefore, the smaller the diameter of the hole, the better the shielding effect.

On the other hand, heat transfer performance is so good that the opening ratio which shows the total area of the hole with respect to the whole area of a porous plate is large. Therefore, the electromagnetic wave shielding performance by the diameter of the hole 11 and the heat transfer performance by the opening ratio where the holes are collected have opposite goals.

As a result, the porous plate 8 having a large heat transfer area by minimizing the gap between the holes 11 while reducing the diameter of the hole 11 can be seen as having an ideal shielding performance and heat transfer performance.

In this way, a microwave oven with a heater prevents electromagnetic leakage to the outside of the cavity, and a perforated plate installed on the wall of the cavity to transmit the radiant heat of the heater into the cavity is used to form a hole and a problem of effectively performing shielding and heat transfer performance. There is a problem related to the trial.

This problem has been shown to increase the aperture ratio by densely arranging a large number of holes per given area, with objectives opposite to each other based on the hole diameter.

However, the perforated plate installed on the wall of the cavity is structurally limited in the processing of the holes necessary to meet the opposite goals of heat transfer performance and shielding performance, and thus the shielding performance and heat transfer performance are low. In order to approach the work process increases, because the glass cover must be mounted separately from the porous plate, the configuration is complicated, there is a problem that the design freedom of the porous plate structure falls.

Accordingly, it is an object of the present invention to provide a porous plate easily and simply in the form of approaching the diameter and aperture ratio of a hole targeted by a porous plate installed on a heat transfer path of a heater.

Another object of the present invention is to simplify the installation work of the perforated plate made on the cavity wall surface and to diversify its shape.

1 is a schematic diagram of a microwave oven.

2 is an internal structure of a microwave oven with a heater.

3 is a detailed view of the porous plate of the microwave oven.

4 is an opening surface structure according to the present invention.

Figure 5 shows the glass cover of Figure 4, (a) is a surface view, (b) is a cross-sectional view taken along the line A-A '.

6 is a door perspective view of the microwave oven.

Figure 7 shows a door glass according to the present invention, (a) is a surface view, (b) is a cross-sectional view taken along line B-B '.

Figure 8 (a) (b) is a cross-sectional view of the porous sheet layer of the door glass according to the present invention.

*** Explanation of symbols for the main parts of the drawing ***

1: cavity 2: tray

3: door 4: magnetron

5: Wave guide 6: Heater

7: Opening surface 8: Perforated plate

9: Heater housing 10: Glass cover

11: Hall 12: door glass

13: Door frame 14: Drive part

20: porous sheet layer 21: porous hole

A feature of the present invention for achieving this object is a heat transfer and electromagnetic wave having a heater around one wall or two or more walls outside the cavity, and having an opening on the contact surface of the heater and the cavity, with a porous plate and a glass cover around the opening. A heater opening surface structure of a microwave oven having a shielding portion;

The opening surface structure,

There is a glass cover which is supported around the cavity wall opening, which glass cover comprises a porous sheet layer on the surface.

Optionally, the porous sheet layer is characterized in that the opening ratio, expressed as a ratio of the total area and the porous hole area, is formed by metallizing at 90% or more.

Optionally, the porous sheet layer on the surface of the glass cover is characterized in that the surface facing the heater is metallized (Metalizing).

Another feature of the present invention is a microwave door structure having a porous part in a door frame covering a cavity and having a door glass separate from the porous part;

Plate-shaped door glass deposited on the door frame,

The door glass is characterized in that it comprises a porous sheet layer coated with a metallization.

Optionally, the inside or outside and inside of the door glass is treated with a porous sheet layer.

Forming a porous sheet layer directly on the glass cover covering the heater opening surface in the microwave oven makes it possible to approach the diameter and aperture ratio of the holes to shield the electromagnetic waves from the heat transfer performance of the heater and close to the target. In addition, when the same purpose is applied to the front glass door, which is another leakage path of electromagnetic waves, it is possible to obtain a result of increasing the shielding effect by reducing the diameter of the hole.

An embodiment of the present invention will be described with reference to the drawings.

4 is a heater opening surface structure, FIG. 5 is a schematic view of the surface treatment of the glass cover covering the heater opening surface, and FIG. 7 is a schematic view of the surface treatment of the door glass as another embodiment.

Commonly, the porous sheet layer 20, which forms a layered structure in glass, is not separated from the glass material but is present in layers or unified in glass. The method of forming the porous sheet layer 20 on the glass is made through a metallizing coating treatment.

Since metallizing is a process of wrapping the surface of a non-electrically conductive material with a metal film, the porous hole 21 is first formed in the metallizing material. The holes are formed in thin sheets to obtain a small diameter hole of the target and a sufficient opening ratio from the target through a different etching process than machining.

However, a hole having a sufficiently small diameter and a portion requiring an opening ratio are limited to the glass cover 10 that covers the opening surface 7 of the heater 6, and small diameter hole processing is important in the front door glass 12.

Since the porous sheet layer 20 formed on the glass cover 10 covering the opening surface 7 is just installed to cover the opening surface 7 of the microwave oven cavity 1, the other porous plate is not set aside. This is because the porous plate is replaced by the layered structure in which the porous plate is added to the glass cover 10.

The porous sheet layer 20 is a material of metal which is a different material from that of the glass material.

The layered shape occupied by the porous sheet layer 20 in the glass cover 10 is formed in the form of a coating on most of the area of the glass cover 10 or partially leaves the edge of the glass cover 10 and the glass cover 10. It is a form that selectively processes inside and outside of.

The arrangement of the porous holes 21 is in the form of densely arranged close to the regular uniform arrangement only in the case of covering the opening surface 7 to create a sufficient opening ratio.

The arrangement of the porous holes 21 in the front door glass 12 is decorated in an arrangement that is advantageous for obtaining holes 21 of small diameter sufficient for the electromagnetic shielding effect rather than the opening ratio.

The porous sheet layer 20 on the glass cover 10 that covers the opening surface 7 maintains the opening ratio represented by the ratio of the total area and the area of the porous hole 21 to 90% or more and is porous on the surface of the glass cover 10. The sheet layer 20 is more advantageous in obtaining heat transfer and shielding effects by selecting the surface opposite the heater 6.

When the porous sheet layer 20 is formed by coating the plate-shaped door glass 12 deposited on the door frame 13 by metallizing, the porous plate 8 is removed by removing the porous plate 8 in the door frame 13. The opening surface corresponding to) is left and the corresponding part is provided with the electromagnetic shielding structure as it is when the door glass 12 is mounted instead of the perforated plate.

The porous sheet layer 20 may be formed inside or outside the door glass 12 and therein.

The porous sheet layer 20 is coated in a layered structure in the glass cover 10 in order to transfer radiant heat of the heater 6 into the cavity 1 to heat food or shield electromagnetic leakage in the cavity 1. Will have the function of. More importantly, when the porous sheet layer 20 is disposed in the layered structure directly on the glass cover 10, different results are obtained. It is such that the ideal arrangement of the porous holes 21 is approached or the change of workability is such.

For example, it is possible to manufacture an advanced type of porous hole that shares electromagnetic shielding and heat transfer characteristics without using any other material than forming a porous plate directly in the cavity 1.

In general, the electromagnetic shielding effect by the arrangement of circular holes is known to be excellent as the diameter of the hole is smaller. In this respect, the small diameter hole processing is difficult to obtain sufficient aperture ratio related to hole processing or heat transfer of small targets through the corrosion process. It can also be easily deposited on the glass cover through metallization coating.

When the porous sheet layer 20 is formed on the glass cover 10 and fixed to the heat transfer opening surface 7 of the heater 6, it is completed to make a porous part in the cavity 1. This eliminates the process of processing a separate perforated plate, and also simplifies the structure since the perforated plate is unified in the glass cover.

This is characterized by the selection of any other material and the arrangement of the ideal porous holes, which are simply fused to the opening surface 7 without compromising yield compared to the artificial porous plate structure provided separately.

Therefore, when the porous sheet layer 20 is directly metallized on the glass cover 10, there is no need for a separate porous plate, and when the diameter of the hole is adjusted to improve the electromagnetic shielding effect, It can be formed while adjusting the diameter of the various holes to be targeted, and the spacing of the holes can be kept tight, so that a sufficient opening ratio appearing in the total area of the holes can be ensured.

If the porous sheet layer 20 with metallized coating is formed on the front door glass 12, the electromagnetic wave shielding effect can be obtained without forming the porous plate on the door frame 13, so that the porous plate formed for electromagnetic shielding purposes Made easier.

The porous sheet layer 20 provided to the door glass 12 may be variously disposed in the form of an inner surface, an outer surface, an intermediate surface, etc. of the door glass 12, and the electromagnetic shielding effect may vary depending on the position.

As described above, the present invention makes the porous sheet layer metalized directly on the glass cover which covers the heater opening of the microwave oven in a layered structure so that the heat of the heater can be transferred into the cavity and shield the electromagnetic leakage of the cavity. This eliminates the need for entry and improves workability, and the glass has porous holes, resulting in a simplified system configuration and greater design freedom for the arrangement of the holes.

In addition, the porous sheet layer layered on the glass cover does not have a difficulty in obtaining the diameter of the target hole for the electromagnetic shielding and heat transfer aperture ratio in the process of coating the glass cover, thereby improving heat transfer and shielding performance. In the same effect, if the porous sheet layer is formed on the door glass which becomes the electromagnetic leakage path, the front door glass structure can be simplified.

Claims (6)

In the heater opening structure of the microwave oven, which has a heater around one wall or two or more walls outside the cavity, and has an opening at the contact surface of the heater and the cavity, the heat transfer and electromagnetic shielding part consisting of a porous plate and a glass cover around the opening. In; The opening surface structure, There is a glass cover supported around the cavity wall opening, the glass cover comprising a porous sheet layer on the surface of the heater opening surface structure of the microwave oven. The method of claim 1, The porous sheet layer is a heater opening surface structure of a microwave oven, characterized in that the metallization film treatment of the opening ratio represented by the ratio of the total area and the porous hole area to 90% or more. The method of claim 1, The porous sheet layer on the surface of the glass cover is selected by coating the surface facing the heater to coat the heater opening surface of the microwave oven. In the microwave oven door glass structure having a porous part in the door frame covering the cavity and having a door glass separately from the porous part; A door glass structure of a microwave oven, characterized in that a porous sheet layer coated with metallization is formed on an inner surface of a plate-shaped door glass supported by a door frame. The method of claim 4, wherein The door glass structure of the microwave oven characterized by the porous sheet layer formed in the outer surface of the door glass. The method of claim 4, wherein The door glass structure of the microwave oven characterized by forming the porous sheet layer in the shape inserted into the door glass.