JPS63223434A - High-frequency heating device - Google Patents

Abstract

PURPOSE:To prevent high-frequency energies from leaking outward by allowing one turn of lead wires to exist in a protruding part provided on the wall surface of a heating chamber, and setting the dimension of the entire part of lead wires at a value amply smaller than a working wavelength. CONSTITUTION:In a heating chamber 1, high-frequency energies of a wavelength lambdaare sealed to subject a food 2 to dielectric heating, and the food 2 is externally heated by a sheath heater 4. A coil-shaped lead wire 6 made of a small resistance member is connected to the end part of a coil-shaped heater wire 7 of the sheath heater 4, and at least one turn of the lead wire 6 is positioned in a hollow protruding part 5 formed on a wall surface 3 of the heating chamber 1 in a contactless manner. Therefore, no coaxial transmission line is formed at this part. Since the dimension L of the entire part of the lead wires 6 is set as L<<lambda, no high-frequency energies leak outward from the end part of the sheath heater 4.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a structure for preventing leakage of high-frequency energy from a sheathed heater terminal in a high-frequency heating device that employs a combined heating method using high-frequency energy and radiated heat from a sheathed heater.

Conventional technology Conventionally, a sheathed heater that penetrates the wall of the heating chamber is installed in the heating chamber to dielectrically heat the food by introducing high-frequency energy, and a combined heating method is used in which the food is externally heated using these heating sources. Often seen in high frequency heating devices.

Problems to be Solved by the Invention However, the terminal part of the conventional sheathed heater that penetrates the wall surface of the heating chamber is coaxial, where the rod-shaped terminal part connected to the terminal part of the sheathed heater can be regarded as the center conductor, and the wall surface of the heating chamber or the outer conductor. Because it forms a transmission line, high-frequency energy leaks to the outside of the heating chamber during high-frequency cooking.
As disclosed in Japanese Patent No. 88690, there is a structure in which a choke structure is formed to form a structure for preventing leakage of high frequency energy.

However, with such a configuration, not only the structure is complicated, but also a sufficient sealing effect cannot be obtained.

Means for Solving the Problems The present invention has been made to solve the above problems, and includes a coiled glue made of a small resistance member at the end of the coiled heater wire of the sheathed heater provided in the heating chamber. - The Riet wire has a gap between the pitches and at least - the winding is positioned so as not to come into contact with the hollow protrusion formed on the wall surface of the heating chamber, and The dimensions of the coiled lead wire located outside the heating chamber, including the heating chamber, are set to be sufficiently smaller than the wavelength used.

By doing this, the protrusion formed on the wall of the heating chamber and the coiled lead wire no longer form a coaxial transmission line, and since the lead wire is a low resistance member, it can be connected to the through hole drilled in the wall. It also suppresses temperature rise inside the hole.

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

In FIG. 1 showing the structure of an embodiment, numeral 1 denotes a box-shaped heating chamber made of a metal plate, which confines high frequency energy and dielectrically heats the food 2 placed inside. 3
A sheathed heater 4 is provided on the upper part of the heating chamber 1 by penetrating the wall surface of the heating chamber 1, so that the food 2 is heated externally. Reference numeral 5 denotes a hollow protrusion formed on the wall surface 3, which is connected to the end portion of the coiled heater wire 7 in the sheathed heater 4 that penetrates the wall surface 3, and is a coiled reed of good conductivity made of a material with low resistance loss. This is a portion where at least one turn of the wire 6 is located so as not to contact the inside. Furthermore, the overall dimensions of the Riet wire 6 provided on the outside of the heating chamber l including the inside of the protrusion 5 from the inside of the wall surface 3 are determined by the working wavelength λ.
, the length of the turns of the Riet wire 6 is L, and the number of turns is n, then nL
The sheathed heater 4 is installed in the heating chamber 1 so that it is turned on. This sheathed heater 4 has a coiled heater wire 7 embedded in a metal jacket conductor 8 and an insulator 9 filled inside the sheathed heater 4. A coiled wire 6 formed of a good electrical conductor is connected by welding or the like, and a terminal 10 is provided on the side of the wire 6 opposite to the heater wire 7. Note that the protruding length of the protruding portion 5 is configured to include at least one turn or more of the lead wire 6.

Next, the operation of the above configuration will be explained.

When introducing high frequency energy into the heating chamber l to dielectrically heat the food 2, the sheathed heater 4 penetrates the wall surface 3.
At least one turn of the coiled lead wire 6 is connected to the protrusion 5 at the end.
Since the lead wire 6 is located inside the lead wire 6, a conventional coaxial transmission line is not formed in this portion, and at least one turn or more of the lead wire 6 can be stably positioned.

Moreover, the overall size of the lead wire 6 provided on the outside of the heating chamber l including the inside of the wall surface 3 and the inside of the protrusion 5 is as described above (nL
＜< Therefore, according to microwave theory, there is no high-frequency energy that travels toward the outside of the heating chamber 1 along the axial direction of the sheathed heater 4, so the high-frequency energy that leaks to the outside from the terminals of the sheathed heater 4 is significantly lower than the standard value. Almost no high frequency energy leaks.

Furthermore, since the wire 6 passing through the protrusion 5 is made of a good conductor, it does not generate heat, thereby suppressing the rise in temperature within the protrusion 5.

Effects of the Invention As described above, according to the present invention, a hollow protrusion is provided in the part that penetrates the wall surface of the heating chamber of the sheathed heater, and an electric wire connected to the terminal part of the coiled heater wire of the sheathed heater is inserted into the protrusion. A coiled lead wire made of a good conductor is passed through the
At least one turn of the Riet wire is located within the protrusion, and the overall dimensions of the Riet wire that penetrates from the inner side of the heating chamber wall surface to the outside of the heating chamber, including the inside of the protrusion, are relative to the wavelength used. Because it is sufficiently small, no high frequency energy leaks to the outside from the terminal of this sheathed heater, so it is possible to prevent high frequency energy from leaking to the outside without forming a complicated choke structure like in the past, and it is simple and reliable. A good sealing effect can be obtained.

Furthermore, since the rieet wire is made of a good conductor with low resistance loss, it is possible to suppress the temperature rise in the hollow part, which prevents thermal deformation in this part and provides a more stable sealing effect. We can provide a high-frequency heating device that can

[Brief explanation of the drawing]

FIG. 1 shows a cross-sectional view of a main part of a sheathed heater terminal portion of a high-frequency heating device showing an embodiment of the present invention. 1... Heating chamber, 2... Food, 3... Wall surface, 4... Sheathed heater, 5... Projection, 6... Coiled Ried wire, 7... Coiled heater wire .

Claims (1)

[Claims] A sheathed heater (4) having a built-in coiled heater wire (7) is provided in a metal heating chamber (1) that dielectrically heats the food (2) by introducing high frequency energy, the heating chamber Hollow protrusion (5) on the wall (3) of (1)
On the other hand, a coiled lead wire (6) made of a small resistance member with at least one turn located within the protrusion (5) without contacting the inner side and spaced apart between each pitch is attached to the coiled heater wire. The heating chamber (1
) A high-frequency heating device characterized in that the dimensions of the lead wire (6) located on the outside are sufficiently smaller than the wavelength used.