JPS6347034Y2 - - Google Patents

Description

[Detailed explanation of the idea] (b) Industrial application fields The present invention relates to a microwave oven.

(b) Conventional Technology It is essential to improve uneven heating in microwave ovens, and various countermeasures have already been considered and implemented. For example, Jitsugan 58-
As seen in No. 143202, in combination with a microwave stirring stirrer, microwave power is supplied into the heating chamber from multiple microwave power supply ports, more specifically, multiple microwave power supply via a cross-shaped waveguide. There is one in which microwave power is supplied into the heating chamber from the mouth. With such a configuration, heating unevenness has been significantly improved. However, it is still not sufficient and there is still plenty of room for improvement.

6 and 7 show the specific structure of such a microwave oven. The 2450MHz microwave from magnetron 1 is heated to heating chamber 2 (width 384mm, depth 412mm, height
The waveguide 3 guided into the interior (288 mm) has a plurality of branch parts 4a to
4d are arranged radially, that is, in a cross shape. A first power feeding port 5 is provided at the gathering portion of the branch portions 4a to 4d, and the first power feeding port 5 is provided in each of the branch portions 4a, 4b, and 4c.
Approximately 1/ of the wavelength λg of the microwave used from the power supply port 5
4 (30mm) apart from the second power supply ports 6a, 6.
b, 6c are further connected to the second power supply ports 6a, 6b, 6
Third power feed ports 7a, 7b, and 7c are provided at positions spaced apart from c by λg/4 (30 mm). The dimensions of each branch portion 4a to 4d of the waveguide 3 are 90 mm in width.
The height is 30 mm, the length of the branch portions 4a, 4b, and 4c in the radial direction is 120 mm (λg), and the length of the branch portion 4d in the radial direction is approximately 230 mm. Further, the first power supply port 5 is a square with a side of 90 mm square, and the second power supply port 6a, 6b, 6c and the third power supply port 7a, 7b,
7c, each branch has a radial dimension of 30 mm (λ
g/4), and the width is 90 mm. Further, in the heating chamber 2, there is provided a stirrer 9 with a radius of 120 mm, which stirs microwaves and is supported by a shaft 8 made of a material with small dielectric loss, which passes through the first power supply port 5. . After cooling the magnetron 1, the stirrer rotates in response to cooling air supplied into the heating chamber 2.

An experiment on uneven heating of food will be conducted using a microwave oven with such a configuration.

First, mix 300 g of Hot Cake Mix in 240 c.c. of water, pour the mixture into a tray (not shown), flatten it evenly, and place it on the bottom wall 2a of the heating chamber 2 as shown in Figure 8a. An experiment (Experiment 1) was conducted in which the specimens were placed in the same manner as described above and heated for 8 minutes with a microwave output of 670 W. As a result, heating unevenness occurs as shown in the figure.
Parts ^a1 , ^a2 , and ^a3 are burnt, part ^a4 remains raw, and the other parts are well-cooked. In other words, the people around him are too good at it.

Next, 300g of hot cake mix and 75g of sugar.
Pour the mixture into 350 c.c. of water containing one raw egg and pour it into a cake container to a uniform thickness of about 40 mm.
9 with a microwave output of 670W.
An experiment (experiment 2) was conducted in which the sample was heated for a minute. Then,
As shown in the figure, uneven heating occurs. The bottoms of parts b ₁ and b ² are charred, and the bottom and sides of part b ³ are charred, while the bottom of part b ⁴ remains raw, and the other parts are well-done. In other words, the people around him are too good at it.

As can be seen from the above experiments, the unevenness of heating is not yet sufficient. The reason for this is that in the above structure, the stirrer 9 is not directly opposed to the third power supply ports 7a, 7b, 7c, and the microwaves from the third power supply ports 7a, 7b, 7c are transmitted to the sixth power supply port 7a, 7b, 7c. As shown in the figure, it directly hits the periphery of the food, and therefore, as mentioned above, the periphery of the food is overcooked, resulting in uneven heating.

(c) Problems to be solved by the invention The purpose of the invention is to obtain a microwave oven that can sufficiently eliminate uneven heating.

(d) Means for solving the problem The present invention provides a microwave oven equipped with a microwave stirrer in a heating chamber to which microwave power is supplied from a plurality of microwave power supply ports. The present invention is characterized in that a microwave reflecting plate is disposed near the power supply port, which is not directly opposed to the stirrer, to prevent microwaves supplied from the power supply port from traveling straight toward the food.

(e) Effect The above means can significantly eliminate uneven heating.

(f) Examples A microwave oven according to an embodiment of the present invention will be described below.

Incidentally, the same parts as in the conventional example are denoted by the same reference numerals, and the explanation thereof will be omitted.

As shown in FIGS. 1 and 2, in each branch portion 4a, 4b, 4c of the waveguide 3, the feed ports that the stirrer 9 does not directly face are the third feed ports 7a, 7b, 7c.
It is. And, the third power supply port 7 of one of them
A microwave reflecting plate 10 is provided only in the vicinity of b. The reflector 10 has a width w of 27 mm and a height h.
is 20 mm, and is arranged so as to prevent the microwave from the third power supply port 7b from traveling straight toward the food.

Then, we will conduct an experiment on uneven heating of food.

In the above experiment 1, the heating as shown in Figure 3a was obtained, and only the small areas of c ¹ , c ² , and c ³ parts were scorched, and only the small areas of c ⁴ and c ⁵ parts were raw. As it is,
Other parts are well done. That is,
Heating unevenness has almost been eliminated.

Next, in the above experiment 2, the heating as shown in Figure 3b was obtained, and the bottom of part _d began to burn, and the bottom of part d ₂ began to burn slightly, and the other parts were well done. . That is, heating unevenness is almost eliminated as well.

FIG. 4 shows another embodiment, in which the third power supply port 7
A microwave reflector 10 is provided near b, and the dimensions in the radiation direction of the branches of the other third power feed ports 7a, 7c are shortened to 15 mm to reduce the opening area of the third power feed ports 7a, 7c. . In this case, the radial dimensions of the branches 4a, 4c themselves are of course shortened by 15 mm.

Then, we will conduct an experiment on uneven heating of food.

In experiment 1 above, the heating as shown in Figure 5a was obtained, and only the small area parts of parts e ¹ , e ² , and e ³ were scorched, and only the small area part of part e ⁴ remained raw. , the other parts are well done. That is, heating unevenness is further eliminated.

Next, in the above experiment 2, the heating as shown in Fig. 5b was obtained, and only the bottom of part f started to burn slightly
Other parts are well done. That is,
Heating unevenness is also further eliminated.

(g) Effects of the invention According to the invention, among the plurality of microwave power supply ports, a microwave agitator is placed near the power supply port that does not directly face the microwave agitator, so that the microwaves supplied from the power supply port travel straight toward the food. Since a microwave reflecting plate is provided to prevent heating from occurring, a practical microwave oven that can significantly eliminate uneven heating can be obtained.

[Brief explanation of drawings]

Figure 1 is a sectional view of a microwave oven according to an embodiment of the present invention, Figure 2 is a sectional view taken along the - line in Figure 1, and Figures 3 a and b.
4 is a sectional view corresponding to FIG. 2 of a microwave oven according to another embodiment of the present invention, and FIGS. A plan view of the main parts to explain the experimental state of the microwave oven, Figure 6 is a cross-sectional view of a conventional microwave oven,
FIG. 7 is a sectional view taken along the line -- in FIG. 6, and FIGS. 8a and 8b are plan views of essential parts for explaining experimental conditions of the same microwave oven, respectively. 1... Magnetron, 2... Heating chamber, 3... Waveguide, 5... First power feeding port, 6a, 6b, 6c...
2nd power supply port, 7a, 7b, 7c... 3rd power supply port,
9...Starrer, 10...Microwave reflector.

Claims (1)

[Scope of utility model registration request] In a microwave oven equipped with a microwave stirrer in a heating chamber that is supplied with microwave power from a plurality of microwave power feed ports, a power feed port is provided near a power feed port that does not directly face the stirrer among the plurality of power feed ports. A microwave oven characterized by disposing a microwave reflector plate that prevents microwaves supplied from the microwave from traveling straight toward food.