JPS6224919B2 - - Google Patents

Description

Detailed Description of the Invention The present invention relates to a high-frequency heating device that sends radio waves generated from a high-frequency oscillator into a heating chamber through a waveguide, and is intended to improve uniform heating performance and further improve the uniform heating performance and output performance of products. The purpose is to minimize variations.

Conventionally, in high-frequency heating devices with stirrer blades that stir radio waves, the high-frequency oscillator made of a magnetron is generally exposed directly on the top of the heating chamber, but the antenna part and the stirrer blade rotation axis are separate parts. Therefore, it is difficult to determine the dimensions of the mutual positional relationship, which causes variations in characteristics such as output. Furthermore, the external size of the high frequency oscillator,
In particular, since the height is high, there is a drawback that the external height dimension of the high-frequency heating device becomes high. In order to reduce the height of this vessel, a method of introducing radio waves from the top of the heating chamber using a waveguide has been considered, but this has the drawback of making the design difficult in terms of uniform distribution and output.

The present invention eliminates the above-mentioned drawbacks of the conventional art with a simple configuration, and one embodiment of the present invention will be described below with reference to the accompanying drawings. In FIG. 1, reference numeral 1 denotes a heating chamber, and radio waves generated from a high frequency oscillator 2 such as a magnetron pass through a waveguide 3 and are sent into the heating chamber through an internal conductor 4 constituting a coaxial line. Reference numeral 5 denotes a support member that supports the internal conductor 4 by the support portion 5b of the support plate 5a. The support member 5 has a hook part 5c, which is a fixed part, hooked to a hole provided on the top surface of the heating chamber 1, and a clip 6 molded from a resin such as polypropylene is inserted into a mounting part 5d, which is another fixed part. It is attached to the top of the heating chamber. Further, the internal conductor 4 is supported by the support portion 5b. Also, the support member 5
is provided with an enclosing part 5e that covers the heating chamber side end of the conductor 4, and a rotating shaft 5f of a stirrer blade formed outside the enclosing part 5e. Further, the rotating shaft 5f is formed to be located on the same axis as the conductor 4. A stirrer blade 7 is rotatably attached to the rotating shaft 5f, and is supported by a synthetic resin stirrer blade receiver 8 so as not to come off the rotating shaft 5f. Reference numeral 9 denotes a fan motor for cooling the high frequency oscillator 2. After cooling the high frequency oscillator 2, air is sent into the heating chamber 1 through an air guide 10 to rotate the stirrer blades 7. Note that 11 is a plate for placing the object to be heated.

In the above configuration, in order to efficiently send the radio waves from the high frequency oscillator 2 to the heating chamber 1, l _B
It is sufficient to fix the dimensions appropriately and adjust the lengths of l _F and l ₂ . Although the length of _l1 affects uniform distribution, it is sufficient that it is approximately λg/4 or more. Furthermore, since the electric field at the tip of the conductor 4 is very strong, it is preferable to buff it to make it spherical. Furthermore, the distance between the tip end of the conductor 4 and the surrounding part 5e of the support member 5 is
If l ₃ gets too close, the electric field will be strong, so the surrounding part 5
Since e may melt, it is desirable to secure at least 4 mm or more.

According to the above configuration, by supporting and fixing the conductor 4 by the support part 5b of the support member 5, the dimensions of the positional relationship between the two, which greatly affect the uniform distribution characteristics and the output characteristics, can be determined with high accuracy, so that the initial characteristics can be maintained. Furthermore, since assembly work can be performed with the conductor 4 fixed to the support member 5, work efficiency is greatly improved and the number of parts stored is reduced, leading to cost reductions in all aspects.

Further, a conductor 4 constituting a coaxial waveguide is provided between the waveguide 3 and the heating chamber 1 at approximately the center of the heating chamber, and the rotation axis 5f of the stirrer blade is located on the same axis as the conductor 4.
By providing
Furthermore, since a large stirrer blade 7 having a radio wave stirring effect can be attached, uniform heating can be easily obtained. Note that the support member 5 is made of polysulfone,
By using a resin with low dielectric loss such as PPS resin, it can be easily molded and is advantageous in terms of cost. Further, when the support member 5 is used in a high temperature section, it is sufficient to use a porcelain material such as ceramic or borosilicate glass.

As is clear from the above description, the present invention provides a conductor constituting a coaxial waveguide between the waveguide and the heating chamber, and a stirrer blade for stirring the radio waves and a rotation axis of the stirrer blade. a support member having;
Since the conductor is supported and fixed to the support member, the dimensional accuracy of the positional relationship between the conductor and the support member is high, variations between products are kept to a minimum, and the number of parts during assembly is reduced, improving workability. The number of parts stored is also reduced. Furthermore, if the support member is made of a resin with low dielectric loss, it can be easily molded, and by providing it on the stirrer blade rotating shaft coaxially with the internal conductor, a high frequency heating device with extremely good distribution uniformity can be obtained. Further, since the distance between the tip of the conductor and the surrounding portion of the support member is at least 4 mm, the support member will not melt due to the electric field.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a high-frequency heating device showing an embodiment of the present invention, and FIG. 2 is a cross-sectional view of the essential parts thereof. DESCRIPTION OF SYMBOLS 1... Heating chamber, 2... High frequency oscillator, 3... Waveguide, 4... Internal conductor, 5... Support member, 5a...
...Support plate, 5b...Support part, 5c...Hook part,
5d... Attachment part, 5e... Surrounding part, 5f... Rotating shaft, 7... Stirrer blade.

Claims (1)

[Claims] 1. A high-frequency oscillator that generates radio waves, a waveguide that guides the radio waves to a heating chamber, a conductor that forms a coaxial waveguide by electric field coupling between the waveguide and the heating chamber, and agitates the radio waves. A stirrer blade, a support plate that supports the conductor, a surrounding part that covers the heating chamber side end of the conductor, a rotating shaft of the stirrer blade formed outside the surrounding part, and a fixing part to the heating chamber are integrated. a molded support member, the support member is made of a low dielectric loss resin, a porcelain material such as ceramic, or a glass material, the stirrer blade rotation axis and the conductor are provided on the same axis, and the conductor The heating chamber side tip of the conductor is formed into a spherical shape, and the support member is configured to support the conductor by the support plate without the surrounding portion contacting the heating chamber side tip of the conductor. High frequency heating device.