JPS63252389A - Radio frequency heater - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a high-frequency heating device that utilizes high-frequency energy and radiated heat from a sheathed heater and employs a nine-complex heating system. This invention relates to a structure for preventing leakage of high frequency energy from a sheathed heater terminal.

Conventional technology A conventional high-frequency heating device employs a combined heating method in which a sheathed heater is installed in a heating chamber to heat two foods externally by introducing high-frequency energy to dielectrically heat the food. This can be seen in the publication number etc.

Problems to be Solved by the Invention According to the above configuration, in the conventional system in which the sheathed heater is provided penetrating through the heating chamber wall surface, the sheathed heater is connected to the central conductor in the portion of the sheathed heater terminal portion that penetrates the heating chamber wall surface. Since the heating chamber wall surface forms a coaxial transmission line that can be regarded as an external conductor, high frequency energy leaks to the outside of the heating chamber, and a choke must be configured to prevent this leakage.

As shown in Japanese Utility Model Application Laid-Open No. 61-88690, this sealing structure is not only very complicated, but also has the problem that a sufficient sealing effect cannot be obtained.

Means for Solving the Problems The present invention has been made to eliminate the above-mentioned drawbacks, and the coaxial transmission line formed in the part where the terminal part of the sheathed heater penetrates the wall surface of the heating chamber is connected to the spiral inside the sheathed heater. Only the shaped heater wire is removed by passing it through the cylindrical body formed from the heating chamber wall surface toward the inside of the heating chamber.

Operation With the above-described structure, the heating chamber wall surface and the spiral heater wire in the sheathed heater passing through the wall surface do not form a coaxial transmission path, so that no high frequency energy leaks to the outside. Furthermore, more stable sealing performance is maintained by giving the cylinder provided on the inside of the heating chamber the same effect as increasing the apparent thickness of the cylinder.

Example An embodiment of the present invention will be described below with reference to the drawings.

The configuration of the embodiment is as shown in FIG.

In the figure, reference numeral 1 denotes a heating chamber made of a metal plate, which confines high frequency energy and dielectrically heats food 2. A sheathed heater 4 is provided penetrating the heating chamber wall surface 3 to externally heat the two foods 2.

A heating chamber wall surface 6 through which the sheathed heater 4 penetrates is provided with a cylindrical body 6 facing toward the inside of the heating chamber 1 . The terminal portion of the sheathed heater 4 that penetrates the heating chamber wall surface 3 is formed by removing the sheathed conductor 7 of the sheathed heater 4 located inside the cylindrical body 6, and forming a gravel-like spiral heater wire 8.
, and at least one turn of the heater wire 8 is connected to the cylinder body 6.
The overall dimension of the spiral heater wire 8 is located within the height of the cylinder 6 from the inside of the heating chamber wall surface 6.

The wavelength to be used is λ, and the length of one turn of the spiral heater wire 8 is λ.

When the number of turns is n, make sure that nL<<λ.

The sheathed heater 4 is fixed inside the heating chamber 1. The sheathed heater 4 has a metal jacket conductor 7 and a spiral heater wire 8 inside the sheathed heater 4. An insulator 9 is packed between the two, and one end of the heater wire 8 is connected to a terminal 10 for supplying current. The structure is equipped with Note that the protruding height of the cylindrical body B is configured to include at least one turn of the helical heater wire 8.

Next, the operation of this embodiment having the above configuration will be explained.

When high frequency energy is introduced into the heating chamber 1 to dielectrically heat the food 5, if the conventional sheathed heater 4 is installed through the heating chamber 1, a coaxial transmission path will be formed at the penetration part 9. In the present invention, the terminal of the sheathed heater 4 that penetrates the heating chamber wall surface 6 is a gravel-shaped spiral heater wire 8 existing inside the sheathed heater 4. Moreover, at least one turn of the spiral heater wire 8 is present within the cylinder body 6.

A coaxial transmission line unlike the conventional one is not formed in this part. Providing the cylindrical body 6 inside the heating chamber wall surface 3 has the effect that at least one turn or more of the spiral heater wire 8 can be stably installed inside. Further, the overall dimension of the spiral heater wire 8 provided in the cylinder body 6 from the inside of the heating chamber wall surface 6 is nL.
((Due to the conditions such that This has been confirmed in experiments using the sheathed heater 4 having the above configuration, and when the above conditions are satisfied, the high frequency energy leaking to the outside from the terminals of the sheathed heater 4 is significantly lower than the standard value. Almost no high frequency energy leaks.

Effects of the Invention As described above, according to the present invention, a cylindrical body is provided on the inner side of the heating chamber surface that penetrates the wall surface of the heating chamber, and the helical heater wire of the sheathed heater is passed through the cylindrical body.

At least one turn of the spiral heater wire is present inside the cylinder, and the dimensions of the entire spiral heater wire, which is located penetrating the cylinder up to the heating chamber wall surface, are sufficiently small relative to the wavelength (nL<<λ), so no high frequency energy leaks to the outside from this sheathed heater terminal.

However, it is possible to prevent external leakage of high-frequency energy without forming a complicated choke structure like in the past.

A simple and reliable sealing effect can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a main part of a high-frequency heating device showing an embodiment of the present invention. 1...Heating chamber, 3...Heating chamber wall surface. 4... Sheathed heater, 6... Cylindrical body. 7... Sheathed conductor, 8... Spiral heater wire.

Claims (1)

[Claims] The sheathed heater (
The heating chamber (1) is attached to the heating chamber wall (3) through which the end of the heating chamber (1) passes through.
) A cylindrical body (6) formed to protrude inward, and a sheathed conductor (7) of the sheathed heater (4) located near the inside of this cylindrical body (6).
) is formed only by the spiral heater wire (8) from which the heater wire (8) is passed through the cylinder (6) without electrical contact, and at least the spiral heater wire (8) One roll is located inside the cylindrical body (6), and the heating chamber wall surface (
3) The overall dimension of the spiral heater wire (8) inside the cylinder (6) from the inside is nL<<λ (where λ is the wavelength used, L is the length of one turn of the spiral heater wire (8), and n is the number of turns of the heater wire (8) located inside the cylindrical body (6).