JPS6321725A - Magnetron - Google Patents

Abstract

PURPOSE:To position a permanent magnet with good accuracy at a low cost by providing the processed part for fixing a permanent magnet on the second L-shaped yoke to be arranged opposite to the first L-shaped yoke having a through hole of a cathode part. CONSTITUTION:A captioned magnetron consists of an anode cylinder 1 having plural vanes 2 radially arranged in the inside, a cathode part 3 arranged in the central part of the anode cylinder, an output part 4 arranged in the vertical direction to the tube axis of the anode cylinder, two permanent magnets arranged in the tube axis direction of the anode cylinder, the first yoke having a cathode part through hole and the second yoke 11 having the processed part 12 for fixing the permanent magnets. Since the second L-shaped yoke 11 is provided with a salient part 12 having a slightly larger diameter than the magnet diameter, the permanent magnets can be easily positioned with good accuracy to be able to secure an uniform magnetic field in the working range, and to prevent leakage of a magnetic flux from the yokes, further to secure stable oscillation.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to magnetrons, and more particularly to a magnetron structure with an improved method of fixing permanent magnets.

Prior Art A conventional magnetron structure is shown in FIG. (Unexamined Japanese Patent Publication No. 56
-3943 Publication) In the figure, 1 is an anode cylinder, 2 is a plurality of vanes arranged in the anode cylinder, and 3 is an anode cylinder 1.
4 is an output antenna section arranged perpendicularly to the anode cylindrical tube axis; 5 is an L-shaped yoke having a cathode through hole; 6 is a type for fixing a permanent magnet; yoke, 7 and 8 are permanent magnets, and 9 is a filter box.

When manufacturing such a conventional magnetron, the permanent magnet 7
is inserted into the cathode part 3 by a howl and fixed with the L-shaped yoke 5, so it can be easily and precisely positioned, but there is a problem with the permanent magnet 8 that this cannot be done. This problem has become particularly important in recent years when small magnets such as alnico magnets and rare earth magnets are used. That is, if the position of the permanent magnet 8 shifts, the magnetic field within the working space 10 becomes non-uniform, and leakage of magnetic flux from the yoke increases, which is not desirable.

Problems to be Solved by the Invention The present invention solves these conventional problems and provides a magnetron that can accurately position a permanent magnet at low cost.

Means to Solve the Problems For this reason, the magnetron of the present invention includes a permanent magnet fixing part on the second L-shaped yoke disposed opposite to the first L-shaped yoke having the cathode through hole. It is based on the set configuration.

Function The present invention allows permanent magnets to be positioned accurately at low cost due to the above-mentioned distance f=7.

Embodiments Hereinafter, embodiments of the present invention will be described based on the accompanying drawings. In Fig. 1, 11 is the first L-shaped yoke provided with a permanent magnet fixing part, and the convex part 1 has a diameter slightly larger than the magnet diameter.
2 is provided. With the above configuration, the permanent magnet can be easily and accurately positioned, which has the effect of ensuring a uniform magnetic field within the working space, preventing leakage of magnetic flux from the yoke, and ensuring stable oscillation.

Next, another embodiment of the present invention will be described using FIG. 2. The point that is similar to the above embodiment is that the second L-shaped yoke 11 is provided with a plurality of cut-outs 13 on the circumference slightly larger than the magnet diameter to serve as a permanent magnet fixing part, With this configuration, the permanent magnet can be positioned accurately, and at the same time the cut-out portion acts as a ventilation hole, ensuring a uniform magnetic field within the working space, preventing leakage of magnetic flux from the yoke, and ensuring stable oscillation. This has the effect of improving the cooling effect of the magnet.

Effects of the Invention As described above, the magnetron of the present invention provides the following effects.

(1) By providing a permanent magnet fixing part on the second rectangular yoke, the permanent magnet can be easily and accurately positioned, ensuring a uniform magnetic field within the working space, preventing magnetic flux leakage from the yoke, and ensuring stable oscillation. This has the effect of ensuring security.

(2) By fixing the permanent magnet and providing ventilation holes, the cooling effect of the magnet can be improved.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a magnetron in a first embodiment of the present invention, FIG. 2 is a sectional view of a magnetron in a second embodiment, and FIG. 3 is a sectional view of a conventional magnetron. 1... Anode cylinder, 2... Vane, 3...
...Cathode section 4 --- Output antenna section, 7.8
...Permanent magnet, 11...L-shaped yoke, 12
．． 13...Permanent magnet fixing part. Name of agent: Patent attorney Toshio Nakao and 1 other person/-
--Intestinal pole cylinder? ---To'in 3--Ichigakusugi 1-4-Eka antenna part 7.8-Permanent magnet tt-L type 臘次/2-11 Permanent gourd convict foot part Fig. 1

Claims (1)

[Claims] an anode cylinder having a plurality of vanes arranged radially therein; a cathode section disposed in the center of the anode cylinder; and an output antenna section disposed in a direction perpendicular to the anode cylinder tube axis. A magnetron comprising two permanent magnets arranged in the tube axis direction of the anode cylinder, a first yoke having a cathode through hole, and a second yoke having a permanent magnet fixing part.