JPH0370918A - Electronic oven - Google Patents

Abstract

PURPOSE:To reduce non-uniformity of heating while controlling the generation of a discharge phenomenon by rotating to drive an agitator attached to a rotary shaft penetrating the inside of a hollow antenna and placed in a heating chamber. CONSTITUTION:A waveguide 3 is connected to a heating chamber 1 through a connecting hole 5 to introduce a high-frequency which a magnetron 2 generates in the heating chamber 1. Since a hollow antenna 7 placed in the waveguide 3 of strong high-frequency energy is fixed by an antenna-fixed stand 6, even if an agitator 9 is rotated, the position of the hollow antenna 7 does not move as it is held firmly enough. Accordingly, the generation of a discharge phenomenon in a part of the waveguide 3 of the hollow antenna 7 is controlled. In addition, the hollow antenna 7 plays the role of the shaft of a rotary shaft 8 and smooth rotation drive of the agitator 9 is realized.

Description

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

(b) Conventional Japanese Patent Publication No. 63-32236 discloses a configuration in which a rotating antenna is provided in a coupling hole portion between a heating chamber and a waveguide to reduce heating unevenness. However, such a tl
llll! In this case, the position of the rotating antenna will shift even if the axis is slightly shaken during rotation. Here, the rotating shaft part of the rotating antenna is also made of metal, so even a slight shake during rotation can cause the waveguide to ell! The distance between the rotary antenna and the waveguide changes, and there is a risk that electric discharge will occur between the rotary shaft of the rotary antenna and the periphery of the coupling hole.

(c) Problems to be Solved by the Invention The present invention reduces uneven heating by providing a rotating antenna in the coupling hole between the heating chamber and the waveguide, and further suppresses the occurrence of electrical discharge phenomena. It provides a range.

(d) Means for Solving the Problems The microwave oven of the present invention includes a heating chamber that houses an object to be heated;
a high-frequency generation source that generates high-frequency waves; a waveguide that is coupled to the heating chamber through a coupling hole and guides the high-frequency waves generated by the high-frequency generation source to the heating chamber; When the hollow antenna is fixed to be located in the coupling hole portion, a rotating shaft passing through the inside of the hollow antenna, a stirring body attached to the rotating shaft and located in the heating chamber, and It is characterized by comprising a drive source that rotationally drives the stirring body.

(e) Operation The stirring body is rotationally driven via a rotating shaft passing through the inside of the hollow antenna, and stirs the high frequency waves in the heating chamber. Further, since the hollow antenna is fixed, the position of the hollow antenna remains stable even when the stirring body rotates, and the occurrence of the phenomenon of radiation is suppressed.

(F) Embodiment FIG. 1 shows a microwave oven which is a first embodiment of the present invention.

Reference numeral 1 designates a heating chamber that accommodates an object to be heated, 2 a magnetron as a high-frequency generation source that generates high-frequency waves, and 3 a waveguide constituted by a waveguide 4 . The waveguide 3 is coupled to the heating chamber 1 through a coupling hole 5 and introduces the high frequency waves generated by the magnetron 2 into the heating chamber 1 . Reference numeral 6 denotes an antenna fixing base made of a dielectric material such as ceramic that closes the coupling hole 5, and 7 is fixed to the antenna fixing base 6 so as to be located in the coupling hole 5 portion, spanning the heating chamber 1 and the waveguide 3. A metal hollow antenna, 8 a ceramic rotating shaft passing through the inside of the hollow antenna 7, 9 a metal piece attached to the rotating shaft 8 with a screw 10 so that its flat surface is perpendicular to the rotating shaft 8. The stirrer 11 is a motor serving as a drive source that rotationally drives the stirrer 9 via a rotating shaft 8.

According to the above groove bottom, the hollow antenna 7 located in the waveguide 3 where high frequency energy is strong is fixed by the antenna fixing base 6, so even if the stirring body 9 is rotated by the motor 11, the position of the hollow antenna 7 is Therefore, the radiation in the waveguide 3 portion of the hollow antenna 7 is
The occurrence of 4 phenomena is suppressed. The hollow antenna 7 also serves as a bearing for the rotating shaft 8, and smooth rotational driving of the stirring body 9 is realized.

Although FIG. 2 shows a second embodiment of the present invention, in the following, parts that are the same as or correspond to those of the already described first embodiment are designated by the same reference numerals, and a description thereof will be omitted.

In this second embodiment, the shape of the stirring body 9 is changed as shown in FIG. That is, the tip of the stirring body 9 is bent vertically upward to form a rising portion 12 parallel to the hollow antenna 7. By adjusting the height H of this rising portion 12 and the size of the distance 11fIL from the center of rotation, the characteristics of the stirring body 9 are changed,
High frequency stirring in the heating chamber 1 can be performed more effectively.

FIG. 3 shows a third embodiment of the invention. In this third embodiment, the shape of the waveguide 4 is changed in the vicinity of the hollow antenna 7. That is, a recess 13 is formed in the portion of the waveguide 4 where the motor 11 is attached. This recess 13 acts as a cavity resonance part for impedance matching between the waveguide 4 and the hollow antenna 7, and enables efficient excitation of the hollow antenna 7 by high frequency waves within the waveguide 3. dent 1
The shape of the waveguide 3 is appropriately determined depending on the characteristics of the waveguide 3, the heating chamber 1, and the like.

FIG. 4 shows a fourth embodiment of the invention. In this fourth embodiment, the shape of the waveguide 4 is changed in the vicinity of the hollow antenna 7, as in the third embodiment. That is,
A convex portion 14 is formed at the portion of the waveguide 4 where the motor 11 is attached. This convex portion 14 performs the function of impedance matching between the waveguide 4 and the hollow antenna 7, and enables efficient excitation of the hollow antenna 7 by high frequency waves within the waveguide 3.

Furthermore, by locating the motor 11 in the concave portion of the portion corresponding to the convex portion 14 on the outer surface of the waveguide 4, the height of the microwave oven can be reduced and it is also useful for downsizing.

In the embodiment shown in FIGS. 1 to 4, the discharge between the upper end of the hollow antenna 7 and the waveguide 4, or between the lower end of the hollow antenna 7 and the stirring body 9, is caused by making the cross section of the end of the hollow antenna 7 curved. This can be suppressed even more reliably by finishing the process.

5 and 6 show fifth and sixth embodiments of the present invention. In these embodiments, the upper end of the hollow antenna 7 is fixed to the waveguide 4 by welding.

According to the groove bottom of this embodiment, the hollow antenna 7 is securely fixed to the antenna fixing base 6 and the waveguide 4, so that the hollow antenna 7 can be more securely attached. The role of the bearing ＼ also improves, making it more reliable.

Note that in the embodiments other than those shown in FIG.
You may use the stirring body 9 which does not have 2.

(G) Effects of the Invention According to the present invention, the stirring body is rotationally driven through the rotating shaft passing through the inside of the hollow antenna, and therefore, the high frequency waves in the heating chamber are stirred by the stirring body, so that uneven heating can be avoided. suppressed. Furthermore, since the hollow antenna is fixed, the position of the hollow antenna remains stable even when the stirring body rotates, and the occurrence of radioactive tq phenomenon is also suppressed.

[Brief explanation of drawings]

The drawings show embodiments of the present invention; FIG. 1 is a front sectional view showing the first embodiment, FIG. 2 is a front sectional view showing the second embodiment, and FIG. 3 is a front sectional view showing the third embodiment. 4 is a front sectional view showing the fourth embodiment, FIG. 5 is a front sectional view showing the fifth embodiment, and FIG. 6 is a front sectional view showing the sixth embodiment. be. DESCRIPTION OF SYMBOLS 1... Heating chamber, 2... Magnetron, 3... Waveguide, 5... Coupling hole, 6... Antenna fixing stand, 7...
・Hollow antenna, 8... Rotating shaft, 9... Stirring body, 1
1...Motor.

Claims (1)

[Claims] (1) A heating chamber that accommodates an object to be heated, a high frequency generation source that generates high frequency waves, and a waveguide that is coupled to the heating chamber through a coupling hole and guides the high frequency waves generated by the high frequency generation source to the heating chamber. , a hollow antenna fixed to the coupling hole portion so as to straddle the heating chamber and the waveguide;
The antenna is characterized by comprising a rotating shaft passing through the interior of the hollow antenna, a stirring body attached to the rotating shaft and located within the heating chamber, and a drive source that rotationally drives the stirring body via the rotating shaft. microwave oven.