JPS6233275Y2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a high-frequency heating device, and particularly to a high-frequency heating device that can improve temperature unevenness characteristics within a heating chamber and perform uniform heating. [Prior Art] Generally, in a high-frequency heating device, as shown in FIG. The structure is such that radio waves are radiated into the heating chamber 6 from a substantially cross-shaped slit portion 5a provided in the disposed rotating disk 5. Conventionally, as shown in FIGS. 2 and 3, the rotating disk 5 of this type of heating device includes a substrate 9 made of a low dielectric material and a metal plate 10 superimposed on the upper surface of the substrate 9. This metal plate 10 is composed of
A cross-shaped slit portion 5a is formed extending radially in four directions from the center. The slit portion 5a is provided with a uniform slit width over the entire length of the slit portion. Moreover, a wind direction plate 11 for rotating the rotary disk 5 by receiving wind from a blower (not shown) is erected at each radially extending slit portion. Incidentally, in a conventional heating device of this kind, as shown in FIG. 1, the opening 7 of the waveguide 2 is arranged at the center of the side surface 8 of the hollow box 3. Therefore, the radio waves inside the hollow box 3 become stronger and non-uniform on the side where the opening 7 of the waveguide 2 is arranged. Generally, in this type of heating device, radio waves from the hollow box 3 are radiated into the heating chamber 6 from the slit portion 5a of the rotating disk 5, and a portion is also radiated from the excitation portion 4. Therefore, when the radio waves inside the cavity box 3 are not uniform, they are radiated into the heating chamber 6 from the slit section 5a of the rotating disk 5 and the excitation section 4 located on the side closer to the opening 7 of the waveguide 2. As the radio waves become stronger, the temperature unevenness inside the heating chamber 6 deteriorates, and there is a drawback that uniform heating cannot be performed. [Purpose of the invention] The present invention was made to eliminate the drawbacks of the conventional high-frequency heating equipment, and its purpose is to heat the load uniformly by improving the temperature unevenness inside the heating chamber. An object of the present invention is to provide a high-frequency heating device that can reduce the heating time. Therefore, the present invention is characterized in that the opening of the waveguide is located at the center of the upper part of the hollow box. [Embodiments of the invention] The invention will be described below with reference to embodiments shown in the drawings. 4 and 5, microwave energy from a magnetron 1 for microwave oscillation is guided to a hollow box 3 via a waveguide 2, and then to a rotating disk 5 disposed inside the hollow box 3. The load 13 on the shelf board 12 is radiated from the slit portion 5a into the heating chamber 6.
It is now heated. Furthermore, the excitation section 4 is isolated from the inside of the heating chamber 6 by a partition plate 14. The position of the opening 15 of the waveguide 2 provided in the hollow box 3 is as shown in FIG.
Unlike the conventional opening 7 position shown in the figure, the drive box 3
The opening 15 of the waveguide 2 is placed at the center of the upper part of the waveguide. The present applicant used a high-frequency heating device having the structure shown in FIGS. 1, 4, and 5, and as shown in FIG. 6, a beaker 1 containing 300 c.c.
6 was placed and heated for 2 minutes and 30 seconds, and the temperature distribution was measured using the following equation. The results are shown in Table 1. Note that the smaller the numerical value of the temperature distribution, the less the temperature unevenness. Temperature distribution = MAX temperature rise value - MIN temperature rise value / average temperature value × 100 (%)

[Effect of idea]

As described above, according to the present invention, since the opening of the waveguide is arranged at the center of the upper part of the hollow box, the temperature characteristics inside the heating chamber are improved and the load is heated uniformly. Furthermore, heating time can be shortened by uniformly heating the load.

[Brief explanation of the drawing]

Fig. 1 is a plan view of a conventional high-frequency heating device, Fig. 2 is a plan view of a conventional rotating plate, and Fig. 3 is a plan view of a conventional high-frequency heating device.
4 is a plan view showing another embodiment of the high frequency heating device of the present invention, FIG. 5 is a vertical sectional view of FIG. 4, and FIG. 6 is a beaker arranged on a shelf board. FIGS. 7 and 8 are plan views of rotary plates according to other embodiments of the present invention. 1... Magnetron, 2... Waveguide, 3... Cavity box, 4... Excitation part, 5... Rotating disk, 5a...
Slit portion, 6... heating chamber, 7... opening, 8...
...Side surface of hollow box, 9... Board, 10... Metal plate,
11... Wind direction board, 12... Shelf board, 13... Load,
14... Partition plate, 15... Opening, 16... Beaker, 17a... Excitation port, 17b... Excitation port.

Claims (1)

[Utility Model Claims] 1. A high-frequency heating device in which high-frequency energy from a high-frequency oscillator is guided through a waveguide to a hollow box and radiated from above into a heating chamber from a cross-shaped slit in a rotating disk placed within the hollow box, the opening of the waveguide being located at the center of the upper part of the hollow box having a circular opening, the center of rotation being the center of the slit in the rotating disk placed within the circular opening of the hollow box, and the center of this slit being located at the center of the opening of the waveguide. 2. A high-frequency heating device as claimed in Utility Model Claim 1, in which the slit width at the center of the slit in the rotating disk placed within the circular opening of the hollow box is formed larger than the slit width at the periphery of the slit. 3. A high-frequency heating device as claimed in Utility Model Claim 1, in which an excitation port larger than the excitation port formed at the intersection of the slits is formed at the center of the slit in the rotating disk placed within the circular opening of the hollow box.