JPH0989268A - Microwave oven - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically remove contamination of a door inner barrier in a microwave oven. SOLUTION: An optical catalyst 20 is applied on an internal surface (surface located on the side of a heating chamber 3) of an inner barrier 12 of a door 4, which catalyst has a function of oxidizing and decomposing a contaminated matter based upon its activation due to light reception. Even if any contaminated matter adheres to the internal surface of the inner barrier 12, the contaminated matter can be removed with the aid of oxidation decomposition action of the optical catalyst 20.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microwave oven having a function of automatically removing dirt on an inner barrier of a door.

[0002]

Conventionally, in a microwave oven, a door for opening and closing the heating chamber is rotatably provided on the front surface of a main body provided with the heating chamber. This door is generally
It was equipped with a punching metal part for preventing microwave leakage, and an inner barrier and an outer barrier made of transparent glass arranged inside (on the heating chamber side) and outside of this punching metal part, and housed in the heating chamber. The structure is such that the food can be seen from the outside.

By the way, in this type of microwave oven, the inner surface of the inner barrier of the door (the surface on the heating chamber side) is accompanied by cooking.
Since dirt substances will be attached to the inside of the heating room, and it becomes difficult to visually check the condition of the food in the heating room from the outside due to the dirt, conventionally, when the dirt becomes conspicuous, the user wipes and cleans it. I was trying to do it. However,
Since the inner barrier gradually becomes dirty, it is hard to notice the dirt, and it is the fact that it becomes noticeable after it becomes quite dirty. For this reason, it is difficult to remove the stains and odors when cleaning, and it takes a lot of time to clean.

Therefore, an object of the present invention is to provide a microwave oven capable of automatically removing dirt on the inner barrier of a door.

[0005]

In order to achieve the above object, the present invention provides a main body having a heating chamber for accommodating and heating food to be cooked, and the main body provided to open and close the heating chamber. A microwave oven having a door having an inner barrier on the side facing the heating chamber, the inner surface of the inner barrier on the heating chamber side has a function of oxidatively decomposing dirty substances based on activation by receiving light. A photocatalyst having is provided.

According to the above means, even if a dirt substance adheres to the inner surface of the inner barrier and becomes dirty, the photocatalyst provided on the inner surface of the inner barrier is activated by receiving light and activated. The substance is oxidatively decomposed, and the odor is also decomposed. Further, since the photocatalyst itself is transparent, even if the photocatalyst is provided on the inner barrier, there is no problem in viewing the inside of the heating chamber through the photocatalyst.

In this case, it is preferable to provide a lamp for irradiating the photocatalyst with light and a punching metal portion outside the inner barrier of the door. If you do this,
Since the punching metal portion reflects the light of the lamp to the inner barrier side, the photocatalyst is more efficiently irradiated with the light.

The photocatalyst is also preferably provided on the outer surface of the inner barrier. In this case, not only the inner surface of the inner barrier, which is easily soiled, but also the outer surface of the inner barrier, can be hardly soiled.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION A first embodiment of the present invention will be described below with reference to FIGS. First, in FIG. 1 showing the overall appearance, a main body 1 of a microwave oven includes a heating chamber 3 having an open front surface inside a cabinet 2. A rectangular door 4 for opening and closing the heating chamber 3 is rotatably provided on the front surface of the main body 1 via a hinge portion 4a, and is located on the right side of the heating chamber 3 for operation. A panel 5 is provided. The operation panel 5 is provided with operation switches 6 and a display 7. A machine room (not shown) is provided behind the operation panel 5, and a magnetron 8 and a high-voltage transformer 9 (see FIG. 6) for irradiating the heating room 3 with microwaves are arranged in the machine room. It is set up.

The door 4 is constructed in detail as shown in FIGS. 2 and 3. The door body 10 made of a metal plate is integrally provided with a punching metal portion 11 having a large number of holes 11a for preventing microwave leakage. Inside the door body 10 (on the side of the heating chamber 3), an inner barrier 12 made of transparent glass is attached by an adhesive 13 at a position facing the punching metal portion 11. The adhesive 13 is made of silicon, for example, and the inner barrier 1
It is provided in the outer peripheral portion of 2 over the entire circumference. A frame-shaped door cover 14 is attached to the inside of the door body 10 so as to be positioned around the inner barrier 12.

An outer barrier 15 made of transparent glass is provided on the outer side (front side) of the door body 10 so as to cover the punching metal portion 11, and the outer barrier 15 is provided.
A door sash 16 is provided on the outer peripheral side. Also,
A handle 17 and a handle cover 18 are provided on a side portion of the door body 10 opposite to the hinge portion 4a, and a latch 19 for holding the door 4 in a closed state is provided.

In the door 4 thus constructed, a photocatalyst 20 made of titanium oxide is provided on both inner and outer surfaces of the inner barrier 12 by coating (for convenience, a portion provided with the photocatalyst 20 is referred to as a photocatalyst). 1 and 2 are indicated by diagonal lines, and in FIG. 3 are indicated by thick lines). In this case, the photocatalyst 20 is not provided on both the inner and outer surfaces of the inner barrier 12 at the outer peripheral portion of about 5 mm (the portion of the surface of the inner barrier 12 where the photocatalyst 20 is not provided is the non-application region 12a).
Therefore, the photocatalyst 20 is provided on the surface of the inner barrier 12 excluding the outer peripheral portion, and does not come into contact with the adhesive 13.

Here, the photocatalyst 20 has a function of adsorbing a dirt substance such as oily smoke and activated by receiving light including ultraviolet rays to oxidize and decompose the adsorbed dirt substance. The coating thickness of the photocatalyst 20 is about several microns, which is almost transparent. Further, since the photocatalyst 20 is hardly discolored due to the influence of heat and is almost transparent even if it is repeatedly used, even if the photocatalyst 20 is provided in the inner barrier 12, the photocatalyst 20 is heated through the inner barrier 12 through the heating chamber. There is no problem in looking inside 3.

In FIG. 4, in the central portion of the ceiling of the main body 1, the cooked food 21 mainly contained in the heating chamber 3 is provided.
A first lamp 22 for illuminating
A second lamp 23 for irradiating light mainly to the inner barrier 12 portion of the door 4 is provided in the front portion of the ceiling portion. In this case, the first lamp 22 is, for example, a filament lamp, and the emission wavelength range is as shown in FIG.
Visible light region of about 500 nm or more (as the visible light region,
The wavelength of about 400 nm to 800 nm) is increasing.
Further, the second lamp 23 is, for example, a discharge lamp in which xenon gas is sealed, and as the emission wavelength range, as shown in FIG. 7, includes an ultraviolet region of about 400 nm or less and a visible light region.

As shown in FIG. 5, the first lamp 22 is attached to the main body 1 via a mounting plate 24 which also serves as a reflection plate, and the first lamp 22 is mounted on the mounting plate 24. A protective cover 25 made of glass is attached so as to cover the inside of the heating chamber 3. The photocatalyst 20 is provided on the upper and lower surfaces of the protective cover 25 by coating. Although not shown in detail, the second lamp 23 is attached to the main body 1 via an attachment plate 26 that also serves as a reflection plate. In FIG. 4, a turntable 27 is arranged at the bottom of the heating chamber 3, and the turntable 27 is rotated by a turntable motor 28 provided at the bottom of the main body 1.

On the other hand, in FIG. 6, both ends of the primary winding 9a of the high voltage transformer 9 are connected to an AC power supply 29. The magnetron 8 is connected to the secondary windings 9b and 9c of the high voltage transformer 9 via a high voltage rectifying circuit 32 including a diode 30 and a capacitor 31 having polarities shown in the figure. The second lamp 23, which is a discharge lamp, is connected to the secondary winding 9d of the high-voltage transformer 9. A glow starter 33 and a noise prevention capacitor 34 are connected to the second lamp 23.

In the above configuration, when cooking the cooked food 21, the cooked food 21 is placed on the turntable 27 in the heating chamber 3, the door 4 is closed, and then the operation switch 6 of the operation panel 5 is operated. To operate. Along with this, the cooked food 21 on the turntable 27 is turned on by the turntable motor 28.
Is rotated, and the magnetron 8 is driven, so that the cooked food 21 is irradiated with microwaves to be cooked. At this time, the first lamp 22 illuminates the cooked food 21 in the heating chamber 3, and the second lamp 23 illuminates the inner barrier 12 of the door 4.

Here, as the cooking progresses, oil and the like may be scattered from the food 21 and adhere to the inner surface of the inner barrier 12 and the lower surface of the protective cover 25 of the first lamp 22 as a dirt substance.

Of these, the light from the second lamp 23 is applied to the inner surface of the inner barrier 12, and the photocatalyst 2 in which the light in the ultraviolet region is applied to the inner surface of the inner barrier 12 is irradiated.
The photocatalyst 20 is activated based on the irradiation with 0, and based on this, the contaminants adhering to the inner barrier 12 are oxidatively decomposed and evaporated into gas. Along with this, the odorous component contained in the dirt substance is also decomposed. At this time, the light emitted from the second lamp 23 and transmitted through the inner barrier 12 is reflected by the punching metal portion 11 and is again irradiated to the inner barrier 12 side. In addition, the first lamp 2 is also provided on the lower surface of the protective cover 25.
The photocatalyst 20 is activated by the irradiation of the second light and the reflected light of the second lamp 23, and the light in the ultraviolet region of the light is irradiated on the photocatalyst 20 applied to the lower surface of the protective cover 25. As a result, the contaminants attached to the protective cover 25 are also oxidatively decomposed to become gas and evaporate. The gasified components are discharged from the heating chamber 3 to the outside by the blowing action of a fan (not shown).

At this time, the photocatalyst 20 is also activated by receiving natural light outside the microwave oven or light in the ultraviolet range included in a lamp such as a fluorescent lamp.
In this case, it is preferable to use a material having a high transmittance for transmitting light in the ultraviolet region as the outer barrier 15. In such a case, the light in the ultraviolet region outside the microwave oven of the inner barrier 12 is preferably used. It becomes possible to irradiate the photocatalyst 20.

According to such an embodiment, even if a dirt substance adheres to the inner surface of the inner barrier 12 of the door 4, the dirt substance can be automatically removed by the oxidative decomposition action of the photocatalyst 20. The barrier 12 can always be kept in a good state and a deodorizing effect can be obtained. Further, the photocatalyst 20 does not need to be heated to a high temperature,
There is an advantage that the effect of oxidatively decomposing the dirt substance can be obtained even at a low temperature.

In this case, since the photocatalyst 20 is provided not only on the inner surface of the inner barrier 12 but also on the outer surface thereof, the inner barrier 1
It becomes possible to prevent the outer surface of 2 from becoming dirty. By the way, conventionally, even if the outer surface of the inner barrier becomes dirty and the user wants to clean it, the door must be disassembled, which is difficult to clean. In this respect, according to the present embodiment, it is possible to prevent the outer surface of the inner barrier 12 from being soiled without having to disassemble the door 4.

Further, the light emitted from the second lamp 23 and transmitted through the inner barrier 12 is reflected by the punching metal portion 11 and is irradiated again toward the inner barrier 12, so that the light is provided on the inner barrier 12. The photocatalyst 20 can be efficiently irradiated with light.

Further, since the photocatalyst 20 is provided excluding the outer peripheral portion of the inner barrier 12 so as not to come into contact with the adhesive 13, the photocatalyst 20 prevents the adhesive 13 from being decomposed. It can be prevented. By the way,
When the photocatalyst 20 is also provided on the outer peripheral portion of the inner barrier 12, the photocatalyst 20 may decompose the adhesive 13 and the inner barrier 12 may come off the door body 10. However, in the present embodiment, such a problem occurs. Can be prevented. Although the outer peripheral portion of the inner barrier 12 not coated with the photocatalyst 20 is contaminated, there is no problem because that portion is almost invisible from the outside.

Further, in this embodiment, since the photocatalyst 20 is also provided on the lower surface and the upper surface of the protective cover 25 of the first lamp 22 for illuminating the inside of the heating chamber 3, the protective cover 25 is automatically soiled. It becomes possible to remove it. By the way, the protective cover 25 is also easily soiled, and when the soiling degree increases, the brightness inside the heating chamber 3 due to the first lamp 22 is reduced and the visibility from the outside is reduced. Such problems can be prevented.

In addition, since a discharge lamp filled with xenon gas is used as the second lamp 23, even if a crack occurs in the glass tube of the second lamp 23 and the gas leaks, For example, unlike mercury gas, it does not harm the human body. Further, since the high voltage transformer 9 for driving the magnetron 8 is used in the lighting drive circuit for lighting the second lamp 23, it is not necessary to provide a special ballast. By the way, the second lamp 23
When lighting such a discharge lamp as described above, a ballast for generating a high voltage is required, but in the present embodiment, it is possible to eliminate the need for providing the ballast.

FIG. 8 shows a second embodiment of the present invention. This second embodiment differs from the above-mentioned first embodiment in the following points. That is, the first lamp 35 for illuminating the inside of the heating chamber 3 is not provided with a protective cover for covering it, and the photocatalyst 20 is applied to the lower surface of the surface of the first lamp 35 by coating. I am trying to provide it.
In this case, in order to efficiently activate the photocatalyst 20, the first lamp 35 should be 400 n containing visible light.
It is preferable to use one having an emission wavelength range in the ultraviolet range of m or less. According to the second embodiment, it is possible to prevent the surface of the first lamp 35 from being contaminated, and to prevent the brightness inside the heating chamber 3 from decreasing.

The present invention is not limited to the above-mentioned embodiments, but can be modified or expanded as follows. For example, using a lamp having an emission wavelength range of 400 nm or less including visible light in the ultraviolet range,
It can be configured to be used both for illumination in the heating chamber 3 and for activation of the photocatalyst 20 of the inner barrier 12. In this case, the shared lamp preferably has an emission wavelength range as shown by the broken line in FIG.

Further, as the lamp, it is also possible to use a discharge lamp which is turned on by receiving the microwave emitted from the magnetron 8. In this case, the discharge lamp can be used without using a power source.

Further, the photocatalyst 20 may be provided also on the inner surface of the wall which constitutes the heating chamber 3. By doing so, the inner surface of the heating chamber 3 can be prevented from being contaminated and the deodorizing effect can be further enhanced. can get.

[0031]

According to the microwave oven described in claim 1,
The stains on the inner barrier of the door can be automatically removed by the oxidative decomposition action of the photocatalyst, and the inner barrier can always be kept in a good state and also the odor can be removed. Further, since the photocatalyst itself is transparent, even if the photocatalyst is provided on the inner barrier, there is no problem in viewing the inside of the heating chamber through the photocatalyst.

According to the microwave oven of the second aspect, since the punching metal portion reflects the light of the lamp toward the inner barrier side, the photocatalyst can be more efficiently irradiated with the light. According to the microwave oven of the third aspect, not only the inner surface of the inner barrier, which is easily soiled, but also the outer surface of the inner barrier, can be less soiled. According to the microwave oven of the fourth aspect, when the inner barrier is attached to the door by using the adhesive, the adhesive can be prevented from being decomposed by the photocatalyst.

According to the microwave oven of the fifth aspect, it is possible to automatically remove stains on the protective cover that covers the lamp, making it difficult to stain the protective cover. According to the microwave oven of the sixth aspect, dirt on the surface of the lamp can be automatically removed, and the lamp itself can be made less likely to become dirty. According to the microwave oven of claim 7, the lamp is
It becomes possible to use both for illumination in the heating chamber and activation of the photocatalyst.

[Brief description of drawings]

FIG. 1 shows a first embodiment of the present invention, and is an external perspective view of a state in which a door is opened.

FIG. 2 is an exploded perspective view of a door

FIG. 3 is an enlarged cross-sectional view of a main part of an inner barrier portion.

FIG. 4 is a longitudinal sectional side view.

FIG. 5 is a vertical sectional front view of a first lamp portion.

FIG. 6 is an electric circuit diagram of a magnetron and a second lamp part.

FIG. 7 is a diagram showing an emission wavelength range of a lamp.

FIG. 8 is a view corresponding to FIG. 5, showing a second embodiment of the present invention.

[Explanation of symbols]

1 is a main body, 3 is a heating chamber, 4 is a door, 8 is a magnetron, 1
1 is a punching metal part, 12 is an inner barrier, 13 is an adhesive, 20 is a photocatalyst, 21 is a cook, 22 is a first lamp, 23 is a second lamp, 25 is a protective cover, and 35 is a first lamp. Is.

Claims (7)

[Claims] 1. A main body having a heating chamber for accommodating and heating food to be cooked, and a door provided on the main body so as to open and close the heating chamber and having an inner barrier on the side facing the heating chamber. In the microwave oven, a photocatalyst having a function of oxidatively decomposing a contaminant based on activation by receiving light is provided on the inner surface of the inner barrier on the heating chamber side. 2. The microwave oven according to claim 1, further comprising a lamp for irradiating the photocatalyst with light, and a punching metal portion outside the inner barrier. 3. The microwave oven according to claim 1, wherein the photocatalyst is also provided on the outer surface of the inner barrier. 4. The microwave oven according to claim 1 or 3, wherein the photocatalyst is provided excluding the outer peripheral portion of the inner barrier. 5. The main body is provided with a lamp for illuminating the inside of the heating chamber, a protective cover for covering the lamp from the inside of the heating chamber is provided, and a photocatalyst is provided on the surface of the protective cover. The microwave oven according to claim 1. 6. The microwave oven according to claim 1, wherein the main body is provided with a lamp for illuminating the inside of the heating chamber, and a photocatalyst is provided on the surface of the lamp. 7. The microwave oven according to claim 2, wherein the lamp has an emission wavelength range of an ultraviolet range of 400 nm or less including visible light.