JPS63217145A - High-frequency heating device - Google Patents

Abstract

PURPOSE:To obtain a sufficient sealing effect of the device by penetrating spiral lead wires of a good conductor through the inside of a link provided outside a heating chamber wall surface, allowing at least one winding of the spiral lead wires to exist in the link and setting the entire length of the lead wires sufficiently smaller than the wavelength. CONSTITUTION:At least one winding or more of spiral lead wires 7 having coil pitch intervals are allowed to exist in a link 5, and the dimension of the entire part of the lead wires 7 is set to satisfy nL<lambda (lambda represents a working wavelength; L, the length of one winding of the lead wire 7; and n, the number of turns of the lead wire). With this construction, the link part 5 and the lead wires 7 do not constitute a coaxial transmission line and have no radiation characteristics in the axial direction of a grill heater 4 from a microwave theory, that is, high-frequency energy leaking outside is not present. Further, the link 5 is provided in the outside direction of a heating chamber 1 so as to afford the same effect as in the case of increase in the apparent thickness of the plate, and further the lead wires 7 are formed by an electrically good conductor whereby the rise in the temperature within the link 5 is suppressed to a low value.

Description

[Detailed Description of the Invention] Industrial Application Field The present invention is a high-frequency heating device that employs a combined heating method using high-frequency energy and a heater as a heating source. Regarding high frequency energy leakage prevention structure.

Conventional technology This type of conventional high-frequency heating device adopts a composite heating method in which a grill heater with a spiral heating wire is installed in a heating chamber to heat food externally by introducing high-frequency energy to dielectrically heat the food. What did you do? Japanese Patent Publication No. 59-1344
This can be seen in Publication No. 27, etc.

Problems to be Solved by the Invention According to the above configuration, in the conventional system in which a grill heater having a spiral heating wire is provided passing through the side surface of the heating chamber,
The part of the spirally wound heater wire that penetrates the heating chamber wall forms a coaxial transmission line that can be regarded as the heater wire, the center conductor, and the heating chamber side wall as the external conductor, and high-frequency energy leaks to the outside of the heating chamber. In addition, it is necessary to construct a choke in the portion where the heater wire penetrates the side wall surface of the heating chamber, which poses the problem that not only is this choke structure complicated, but also 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 present invention has been made in order to eliminate the above-mentioned drawbacks. A spiral lead wire is provided which is an electrically good conductor and has a coil pitch similar to the heater wire, and this spiral lead wire passes through a link provided outside the heating chamber, so that at least the spiral lead wire The entire dimension of the helical lead wire located outside the heating chamber, including the inside of the link from the inside of the heating chamber wall, is nL<λ (the length is determined by the wavelength used). (about 120o+m, L is the length of one turn of the spiral lead wire, and n is the number of spiral lead wires located inside and outside the link).

Operation With the above-described configuration, there is no radiation characteristic to the outside because no coaxial transmission line is formed between the heating chamber wall surface and the spiral lead wire passing through the heating chamber wall surface. Furthermore, by providing a link toward the outside of the heating chamber, the apparent effect is the same as increasing the thickness of the upper plate, and by forming a spiral lead wire with a good electrical conductor, the temperature inside the link increases. Keep it low.

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, l denotes a heating chamber made of a metal plate, which confines high-frequency energy and dielectrically heats the food. A grill heater 4 having spiral heater wires 3 with coil pitches extending through the heating chamber wall 2 is provided to externally heat the food. A link 5 is provided on the heating chamber wall surface 2, through which the grill heater 4 passes, toward the outside of the heating chamber 1. The outer periphery of the spiral heater wire 3 is supported by a cylindrical heater support tube 6 made of a material such as quartz or ceramics that has high heat resistance and excellent heat conduction. Similarly to 3, the part of the end of the spiral heater wire 3 with the coil pitch separated and penetrating the heating chamber wall surface 2 is connected to the spiral lead wire 7 by welding to the spiral heater wire 3. #Spiral lead wire 7
is formed of a good electrical conductor with low resistance loss, and the link 5
At least one turn of the spiral lead wire 7 is located inside the link 5 without contacting the other parts. Furthermore, including the inside of the link 5 from the inside of the heating chamber wall surface 2,
The overall dimension of the spiral lead wire 7 provided outside the heating chamber l is nL < λ (however, the input is approximately 120+ at the wavelength used)
am, L is the length of one turn of the spiral lead wire 7, and n is the number of turns of the spiral lead wire 7 located inside and outside the heating chamber wall surface 2. ). Note that the grill heater 4 having the above configuration is generally called a halogen heater.

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

Inside the link 5 is a helical lead wire 7 with a coil pitch interval, so that at least one turn or more is present inside the link 5, and is provided from the inside of the heating chamber wall 2 to the outside of the heating chamber 1, including the inside of the link 5. @Overall dimensions of spiral lead wire 7?
By setting the condition that L < λ, link 5
The portion and the spiral wire 7 do not constitute a coaxial transmission line, and according to microwave theory, they do not have radiation characteristics in the axial direction of the grill heater 4. In other words, this means that there is no high-frequency energy energy propagating along the grill heater 4 toward the outside of the heating chamber l. This was also confirmed in an experiment using the grill heater 4 having the above-mentioned configuration a.
When the above conditions are satisfied, the high frequency energy leaking to the outside from the terminal of the grill heater 4 is significantly lower than the standard value, and almost no high frequency energy leaks. Providing the link 5 on the outside of the heating chamber wall surface 2 has the effect that at least one turn or more of the spiral lead wire 7 can be stably installed inside the link 5. Furthermore, forming the spiral lead wire 7 from a good conductor has the effect of suppressing the temperature rise inside the link 5 through which it passes.

Effects of the Invention As described above, according to the present invention, a spiral lead wire of good conductivity is passed through the inside of the link provided on the outside of the heating chamber wall surface, and one turn of the spiral lead wire with at least the coil pouches spaced apart is connected to the link. The overall dimension of the spiral sword wire, which is located inside the heating chamber wall surface and penetrates from the inside of the heating chamber wall surface to the outside of the heating chamber including the inside of the link, is sufficiently small (closely inserted) with respect to the wavelength. Therefore, no high frequency energy leaks to the outside from this grill heater terminal. Therefore, leakage of high frequency energy to the outside can be prevented without constructing a complicated choke structure as in the conventional case, and a simple and reliable sealing effect can be obtained. In addition, by providing a link, even if the helical lead wire is misaligned, the helical lead wire can be stably positioned on the single winder, and the helical sorted wire is a good conductor with low resistance loss. Because of this structure, it is possible to suppress the temperature rise within the link that passes through this, so that a more stable sealing effect can be obtained without causing thermal deformation of this part.

[Brief explanation of the drawing]

FIG. 1 is an enlarged sectional view of a main part of a grill heater terminal portion of a high-frequency heating device showing an embodiment of the present invention. l... Heating chamber 2... Heating chamber wall surface 3... Spiral heater wire 4... Grill heater 5... Link 6... Heater support tube 7... Spiral lead wire

Claims (1)

[Claims] A metal heating chamber (1) for dielectrically heating food by introducing high-frequency energy, and a material with high heat resistance and low dielectric loss, such as ceramics, provided through this heating chamber (1). A grill heater (4) (generally called a halogen heater) consisting of a spiral heater wire (3) housed in a heater support tube (6) consisting of a A link (5) is provided in which the heating chamber wall surface (2) through which the end portion passes protrudes to the outside of the heating chamber (1), and the lead wire of the grill heater (4) located near the inside of the link (5) is connected. It is formed of a spiral lead wire (7) made of a material with low resistance loss and has coil pitches spaced apart, and is connected to a spiral heater wire (6) that has coil pitches spaced apart in the grill heater (4). , this spiral lead wire (7) passes through the link (5) without contacting it, and this spiral lead wire (
At least one turn of the lead wire (7) is located inside the link (5), and the spiral lead wire (7) is provided on the outside of the heating chamber (1), including the inside of the link (5) from the inside of the heating chamber wall (2). ) is nL<λ (however, λ is the wavelength used and is approximately 120m)
m and L are the lengths of one turn of the helical lead wire (7), and n is the number of turns of the helical lead wire (7) located inside and outside the link (5). A high-frequency heating device characterized by having a grill heater (4) having a structure that satisfies the following.