JP2003338250A - Magnetron - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a magnetron in which the dimension of the output terminal is small and the external diameter of the antenna cylinder can be made smaller. <P>SOLUTION: In an exhaust pipe 11 in which the exterior diameter dimension is made T<SB>1</SB>, an opening end part 11a side of one end side is enlarged toward the outside and the cross-sectional shape forms a U-shape, and which has a wall face 11b that is approximately parallel to the exhaust pipe 11, and a first annular crevice 11c is formed so that the internal diameter dimension of this wall face becomes T<SB>2</SB>and the depth dimension becomes H<SB>1</SB>. Furthermore, a second annular crevice 11f is formed so that an opening end part 11d of the first annular crevice 11c is further enlarged toward the outside, and the cross-sectional shape forms a U-shape, and an opening end part 11e becomes to have a dimension T<SB>3</SB>so that this is airtightly sealed in an insulating ring. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetron used in a microwave heater or the like, and more particularly to improvement of the output section structure.

[0002]

2. Description of the Related Art A magnetron is used as a high-frequency source in electric appliances using microwaves such as microwave heaters and microwave discharge lamps.

A conventional magnetron will be described below with reference to the drawings.

FIG. 3 is a cross-sectional view of a main part of a conventional magnetron, in which a cylindrical anode body 1 and an anode body 1 projecting from the inner peripheral surface toward the center are arranged so as to maintain a predetermined distance. A plurality of vanes 2 and an anode part 4 composed of a pressure equalizing ring 3 for alternately connecting the vanes, a side pipe 5 for hermetically sealing the output side opening of the anode part 4, and a side pipe. 5
An insulating ring 6 hermetically sealed in the opening on the smaller diameter side of
An exhaust pipe 7 airtightly sealed to the opening of the insulating ring 6,
One end is connected to the vane 2 and the other end is the side tube 5, insulating ring 6
And the output pipe 8 extending through the exhaust pipe 7 in a non-contact manner, and the output pipe 7 and the exhaust pipe 7 are pressed together, and the antenna tube 9 is attached to a part of the pressed exhaust pipe. An output terminal 10 is formed for mounting and emitting microwaves.

[0005]

The output terminal 10 of the conventional magnetron configured as described above functions as a coaxial waveguide converter when attached to a waveguide which is a general microwave transmission circuit. , The output terminal 10, that is, the dimension d of the coupling portion with the waveguide is generally d≈λ / 4, and 2.4.
With a 5 GHz magnetron, this is about 30 mm.

However, the size of the insulating ring 6 has a restriction that it cannot be made smaller than 8 mm in the conventional magnetron of several 100 W class in order to prevent discharge due to the microwave electric field. Moreover, the frequency is 5.8 GH
When using a z-band magnetron, the size of the waveguide becomes smaller depending on the wavelength of the oscillating microwave. Further, since the output terminal 10 of the magnetron is also small, the magnetron in the 5.8 GHz band has a problem that the distance between the magnetron and the waveguide wall surface becomes small and discharge occurs when the exhaust pipe has the same shape as the conventional one. Therefore, a method of reducing the height of the exhaust pipe has been taken, but the stress generated when the exhaust pipe is pressed to form the output terminal 10 also affects the airtight joint between the insulating ring and the exhaust pipe. , The exhaust pipe is deformed or the deformed exhaust pipe can not be attached to the antenna cylinder properly,
There is a problem that a gap is generated between the antenna tube and the exhaust pipe, and discharge is generated from there.

[0007]

In order to solve the above-mentioned problems, a magnetron of the present invention comprises an anode part, an output lead wire extending from the anode part, an insulating ring, and an insulating ring hermetically sealed at one end side. The attached exhaust pipe and the output lead wire penetrate the insulating ring and extend in the vicinity of the opening on the other end side of the exhaust pipe, and the exhaust pipe and the output lead wire are integrally pressure-contacted to each other And a first annular recess formed so that one opening end side of the exhaust pipe expands outward to form a U-shaped cross section. The opening end of the first annular recess expands outward to form a second annular recess, and the opening end of the second annular recess is air-tightly attached to the insulating ring, and the exhaust pipe of the magnetron is After being pressed, the exhaust pipe Antenna tube is configured is mounted on the annular recess.

With this configuration, it is possible to reduce the dimension d of the output terminal of the magnetron and also reduce the outer diameter of the antenna cylinder.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The magnetron of the present invention will be described in detail below with reference to the drawings.

1 and 2 are cross-sectional views of the essential parts of a magnetron according to an embodiment of the present invention. Incidentally, the same parts as those of the prior art are designated by the same reference numerals and the description thereof will be omitted.

In the figure, a side tube 5 that hermetically seals the output side opening of the anode section 4, an insulating ring 6 that is airtightly sealed to the small diameter side opening of the side tube 5, and one end has a vane. 2 and an output conductor 8 which is connected to 2 and has the other end penetrating the side pipe 5 and the insulating ring 6 in a non-contact manner and extending into the exhaust pipe 11,
The exhaust pipe 11 having the outer dimension of T1 has a wall surface 11b that is substantially parallel to the exhaust pipe 11 and has a U-shaped cross section with the opening end 11a side of one end side expanding outward and the inner diameter of this wall surface. The first annular recess 11c is formed so that the dimension is T2 and the depth dimension is H1.

The opening end 1 of the first annular recess 11c
The second annular recess 11f is formed so that 1d further spreads outward and has a U-shaped cross section, and the opening end 11e has a dimension T3 that is airtightly sealed to the insulating ring 6.

After the exhaust pipe 11 constructed as described above is pressed against the output conductor 8 integrally, the wall surface 11b of the exhaust pipe 11
An antenna tube 12 formed to have a size to abut is attached to form an output terminal 13 for radiating a microwave.

That is, the output terminal constructed in accordance with the present invention can be reduced in size by pressing the exhaust pipe 11 to the inner diameter side of the annular recess 11c, thereby reducing the size of the pressure contact portion, and further, reducing the size of the insulating ring 6 and the exhaust gas. The stress strain generated at the joint with the pipe 11 was absorbed.

The present inventor introduced the above contents into an actual magnetron, and as a result of experiments, as a result, the height d of the coupling portion inserted into the waveguide can be made as small as 13 mm, and the oscillation frequency is 5. D≈λ in 8 GHz magnetron
/ 4 can be set, and the performance as a coaxial waveguide converter can be maintained.

From the shape of the exhaust pipe in the present invention,
It was possible to reduce the outer diameter of the antenna cylinder, and to take measures against discharge by increasing the distance from the metal wall of the waveguide.

[0017]

As described above, according to the magnetron of the present invention, the size of the output terminal of the magnetron is reduced,
Further, since the outer diameter of the antenna tube can be reduced, the dimension of the coupling portion with the waveguide of the magnetron in the high frequency band can be set to d≈λ / 4, and the coaxial waveguide converter can be obtained. It is possible to maintain the above performance and solve the discharge countermeasure.

[Brief description of drawings]

FIG. 1 is a sectional view of a main part of a magnetron according to the present invention.

FIG. 2 is a sectional view of an essential part of an exhaust pipe of a magnetron according to the present invention.

FIG. 3 is a sectional view of a main part of a conventional magnetron

[Explanation of symbols]

6 insulating ring 8 output conductors 11 exhaust pipe 12 antenna tube 13 output terminals d Joint height

Claims (2)

[Claims] 1. An anode part, an output conductor extending from the anode part, an insulating ring, an exhaust pipe whose one end side is hermetically sealed to the insulating ring, and the output conductor penetrating the insulating ring. And extending near the other end side opening of the exhaust pipe,
A magnetron comprising: the exhaust pipe and the output conductor, which are integrally pressure-contacted with each other; and an antenna cylinder attached to the pressure-contact portion, wherein one opening end side of the exhaust pipe expands to the outside and has a cross-sectional shape. First to form a U-shape
Forming an annular recess, the opening end of the first annular recess widens outward to form a second annular recess, and the opening end of the second annular recess is airtightly attached to the insulating ring. A magnetron that is characterized by being configured. 2. The magnetron according to claim 1, wherein after the exhaust pipe of the magnetron is pressure-welded, an antenna cylinder is attached to the first annular recess of the exhaust pipe.