JPS6353839A - Magnetron device - Google Patents

Abstract

PURPOSE:To make a microwave leaking from a stem part be absorbed into a semicircular ferrite magnet so that the wave is prevented from leaking outside a device, by sealing a flange part of a sealing member on an end part of an anode cylinder whose tube axis is shaped approximately in a L character, and besides disposing a cathode stem, which is sealed on a cylindrical part of the sealing member, on a cut-out part of the semicircular ferrite magnet. CONSTITUTION:Pole pieces 2 and 3 are installed on upper and lower parts of an anode cylinder 1 housing a cathode 9 on its central part and a plurality of anode vanes 4 disposed facing this cathode. A semicircular ferrite magnet 18 is mounted on the piece 2 and a cylindrical part 6 of a sealing member 5 connected with the cathode 9 is inserted into a cut-out part of this magnet 18 and a cathode stem 8 is fixed on a side opposite to the cut-out part. Successively, a lead conductor from the stem 8 is connected with a capacitor 22, which perforates a yoke 21, through a choke coil 12. An antenna 17 connected with the vanes 4 is made to perforate the piece 3 and a circular ferrite magnet 19 and connected with a sealing part 16 for an exhaust tube. Thus, a leaking microwave, which can not be interrupted by the use of a LC filter circuit, is interrupted by the use of the yoke 21 and the magnet 18.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to magnetron devices, particularly compact magnetron devices.

2. Description of the Related Art In a conventional magnetron device, a cathode terminal lead-out portion and an LC filter circuit element connected thereto are disposed within a filter case in order to prevent microwave leakage.

Problems to be Solved by the Invention In recent years, as microwave application devices such as microwave ovens have become smaller, magnetron devices have also become smaller. However, in a structure in which the cathode terminal lead-out portion and the LC filter circuit element are housed within the filter case, there is a limit to miniaturization.

The present invention seeks to provide a compact magnetron device that does not require a filter case as in conventional magnetron devices.

Means for Solving the Problems The magnetron device of the present invention has a sealing body consisting of a cylindrical portion whose tube axis is approximately L-shaped and a flange-like portion integrally formed at one end of the cylindrical portion. A cathode stem that is sealed to one end of an anode cylindrical body at a flange-shaped part and further sealed to the cylindrical part of this sealing body is arranged in a notch part of a semi-annular ferrite magnet. It is.

Operation According to the above configuration, leakage microwaves from the cathode stem portion are absorbed by the ferrite magnet, so leakage of microwaves to the outside of the device is substantially prevented.

EXAMPLE Below, a magnetron device according to an example of the present invention will be described with reference to the drawings.

FIG. 1 is a plan view of the main part of this embodiment, and FIG. 2 is a partially cutaway side view of the main part.

In the figure, 1 is an anode cylinder, and pole pieces 2 and 3 whose diameters are slightly smaller than the outside diameter of the cylinder are attached to both ends of the anode cylinder. A resonant cavity is formed parallel to the axis and radially arranged. Reference numeral 5 denotes a sealing body made of non-magnetic metal, which is composed of a cylindrical portion 6 whose tube axis is approximately L-shaped, and a flange-like portion 7 integrally formed at one end of the cylindrical portion 6. The flange-like portion 7 of the sealing body 5 is arranged on the pole piece 2, and its peripheral portion is sealed to the peripheral portion of the pole piece 2 and the end portion of the anode cylinder body 1.

A cathode stem 8 is attached to the other end of the cylindrical portion 6 of the sealing body 5 and sealed. 9 is a cathode, which is arranged along the axis of the magnetron tube. The lead wire 10.11 is led out through the hole in the pole piece 2 parallel to the magnetron tube axis, placed inside the cylindrical portion 6 of the sealing body 5 parallel to its central axis, and further penetrates the cathode stem 8. and is held sealed thereto. Reference numerals 12 and 13 indicate choke coils, which are connected to lead wires 10 and 11, respectively. These choke coils 12, 13 share a central axis, are perpendicular to the magnetron axis, and are arranged symmetrically. 14 is a cylindrical sealing body made of non-magnetic metal, and has a flange-like portion at one end. This flange-shaped portion is placed on the pole piece 3, and its peripheral portion is sealed to the peripheral portion of the pole piece 3 and the end portion of the anode cylinder 1. 15 is a ceramic cylindrical body, one end of which is attached to the end of the sealing body 14, and the other end of which is attached with the exhaust pipe sealing part 16. 617 is an antenna, one end of which is connected to one of the anode vanes 4. and the other end is pole piece 3
It is guided out of the anode cylinder body 1 through the through hole, and its tip is connected to the exhaust pipe sealing part 16. Ferrite magnets 18 and 19 are arranged on both sides of the anode cylinder 1 so as to surround the magnetron tube axis. One ferrite magnet 18
has the shape of a partially cut-off semicircle. A portion of the cylindrical portion 6 of the sealing body 5 and the cathode stem 8 are arranged in the cutout portion 20. The sealing body 5 is configured such that its height is lower than the thickness of the ferrite magnet 18. The other ferrite magnet 19 has an annular shape, and the sealing body 14 fills its hole penetrates through.

Reference numeral 21 denotes a frame-shaped yoke, which together with ferrite magnets 18 and 19 constitutes a magnetic circuit passing through the anode cylinder 1. 22 is a feedthrough capacitor, which is attached to the frame-shaped yoke 21 by penetrating it, and one terminal of which is connected to the choke coil 12.
．． 13, respectively. With these choke coils 12° 13 and feedthrough capacitor 22,
An LC filter circuit is configured. 23 is a plurality of heat radiation fins, which are attached to the anode cylinder 1, and both ends of which are connected to the yoke 21.
is in contact with the inside of the When the magnetron is operated,
The heat generated by it is mainly transferred from the anode cylinder 1 to the heat dissipation fins 2.
3 and further conducts to the yoke 21 through them. At this time, when cooling air is sent parallel to the radiation fins 23 (in the direction of the plane of the drawing in FIG. 1), heat is removed from the radiation fins 24 and the yoke 21, and the magnetron device is cooled.

In the magnetron device of this embodiment, the cathode stem 8
Microwave leakage through the lead wires 10.11 and 10.11 is substantially blocked by an LC filter circuit consisting of a choke coil 12.13 and a feedthrough capacitor 22. and,
Since the cathode stem 8 is disposed in the notch 20 of the ferrite magnet 18, microwaves that leak without being blocked by the LC filter circuit are absorbed by the ferrite magnet 18, and the leakage is significantly reduced.

It is possible that the ferrite magnet 18 absorbs microwaves, causing its temperature to rise and become demagnetized, but since the leaked microwave energy is small and the oscillation time is generally short, forced air cooling can reduce the temperature rise. Can be suppressed.

Effects of the Invention The present invention has a structure in which the cathode stem is disposed in the notch of a semi-annular ferrite magnet, so the filter case can be eliminated, and the magnetron device can be downsized (and its The number of parts can be reduced and the structure can be simplified.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a main part of a magnetron device embodying the present invention, and FIG. 2 is a partially cutaway plan view thereof. 1...Anode cylinder, 5...Nonmagnetic metal sealing body, 8...Cathode stem, 9...
Cathode, 10.11... Lead wire, 12.13.
...Choke coil, 18.19...Ferrite magnet, 20...Notch part, 21...
...Yoke, 22...Feedthrough capacitor. Name of agent: Patent attorney Toshio Nakao and 1 other person

Claims (1)

[Claims] It has an anode cylinder, a cylindrical part whose tube axis is approximately L-shaped, and a flange-shaped part integrally formed at one end of the cylindrical part,
a sealing body in which the brim portion is sealed to one end of the anode cylinder; a cathode disposed within the anode cylinder along its central axis; and a lead portion of the cathode that is sealed to one end of the anode cylinder. a cathode stem led out from one end of the body and having a tip fixed through the sealing body; a semi-annular ferrite magnet having a notch disposed at the one end of the anode cylinder; . A magnetron device comprising: a yoke forming a magnetic circuit together with the ferrite magnet; and the cathode stem is disposed in a notch of the ferrite magnet.