JPS5981834A - Magnetron - Google Patents

Abstract

PURPOSE:To fix easily and firmly while to improve cooling effect of spiral fin by performing relative positioning between yoke and magnetron through a positioning board. CONSTITUTION:Contour of positioning board 8 is such that diameter phiD will fit to the inner diameter phiD of circular rib 12 of inner face and fixed. Diameter phia of central hole 9 of said board 8 is approximately same with diameter phia at the high frequency output section 7 of magnetron body and when fitting said section 7 in said hole 9, relative position against a yoke of high frequency output section is fixed firmly through the positioning board. A rising 10 is provided at the circumference of said board 8 to choke a gap against a spiral fin 1 at the corner of shoulder of yoke 5a. Since cooling water must pass in the way of spiral fin 1, heat source or an anode tube 2 is cooled efficiently.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a magnetron in which the relative positions of a yoke and a magnetron are reliably fixed and the cooling effect of a spiral fin is improved.

[Prior art]

FIG. 1 shows an example of a conventional magnetron using spiral fins, where FIG. 1A is a front view and FIG. 1B is a sectional view taken along the line X--X in FIG. In the figure, 1 is a spiral fin, 2 is an anode cylinder of the magnetron body, 3 is an upper magnet, 4 is a lower magnet, 5 is an upper yoke, 6 is a lower yoke, and 7 is a high frequency output section.

Spiral fins are inexpensive because material can be extracted economically, but there is little freedom in changing the shape, which causes the following problems.

``In order to increase the heat dissipation area, the number of turns must be increased, which narrows the fin pitch and makes it difficult for cooling air to pass between the fins.

In a magnetron equipped with spiral fins, it is difficult to determine the relative position of the yoke and the anode cylinder, and there is no reliable method for fixing the relative position against vibrations and shocks, and the magnetron body is likely to shift position.

[Purpose of the invention]

The object of the present invention is to eliminate the problems of the prior art described above and position the main body using spiral fins.

It is an object of the present invention to provide a magnetron which can easily and reliably fix relative positions and can provide a good cooling effect.

[Summary of the invention]

In order to achieve the above object, the present invention provides a positioning plate between the yoke on the high frequency output side and the permanent magnet for positioning and fixing the high frequency output part of the magnetron main body relative to the yoke. A part of the periphery of the positioning plate is sandwiched in order to facilitate the positioning of the magnetron body and securely fix it, and to prevent the cooling air from passing through where it is not useful for cooling the magnetron heat generating part. A baffle board was placed in the ineffective cooling air path by cutting it up. A gasket made of metal mesh or the like is filled around the high frequency output part of the magnetron main body between it and the waveguide etc. to prevent high frequency output leakage at the high frequency output extraction point. For this reason, it is desirable to have some clearance between the yoke (hole) and the high-frequency output part of the magnetron body, but since the gasket is soft,
It was not possible to prevent misalignment between the magnetron main body and the yoke due to vibration or impact. Therefore, it is very effective to position and fix the main body using a positioning plate.

[Embodiments of the invention]

The present invention will be explained below with reference to the drawings. Figure 2 is a front view of one embodiment of the present invention (the front half of the fin has been removed).
) is a perspective view of the positioning plate 8, and (b) is a perspective view of the upper yoke 5a according to the present invention. As shown in Figure 3, the positioning plate 8
The outer diameter (φ0) is the annular lip 1 on the inner surface of the upper yoke a.
It fits the inner diameter (φ0) of No. 2, and is designed to fit and be fixed exactly.

The diameter (φa) of the center hole 9 of the positioning plate 8 is approximately equal to the diameter (φa) of the high frequency output section 7 of the magnetron main body.
If the high frequency output section 7 is fitted into the center hole 9, the relative position of the high frequency output section with respect to the yoke will be reliably fixed via the positioning plate.

Note that the diameter of the hole provided in the upper yoke 5a through which the high frequency output portion 7 passes is slightly larger than the diameter φ8 of the high frequency output portion.

As mentioned above, this is to facilitate filling of the metal mesh gasket for preventing high frequency output leakage. Further, there is a cut-and-raised part 10 around the positioning plate 80, as shown in FIG. 2, to close the gap that occurs between the shoulder corner of the yoke 5a and the spiral fin 1. In this way, the cooling air is forced to mainly pass through the middle of the spiral fins 1, and the anode cylinder 2, which is a heat source, is efficiently cooled. In FIG. 2, reference numeral 11 denotes a baffle plate for the ineffective air passage between the lower yoke 6 and the spiral fin 1, which may be provided by cutting and raising the lower yoke 6 or as a separate member.

〔Effect of the invention〕

As explained above, according to the present invention, the relative positioning and fixing of the yoke and the magnetron body can be easily and reliably performed, and the cooling effect of the spiral fin can be further enhanced.

[Brief explanation of the drawing]

FIG. 1(a) is a front view of a conventional magnetron using spiral fins, FIG. 1(b) is a sectional view taken along line xx' in FIG. 1(a), and FIG. 2 is a front view of an embodiment of the present invention. FIG. 3(a) is a perspective view of a positioning plate according to the present invention, and FIG. 3(b) is a perspective view of an upper yoke according to the present invention. ■...Spiral fin, 2...Anode cylinder, 3...
・Upper magnet, 5a... Upper yoke, 7... High frequency output section,
8... Positioning plate, 9... Center hole, 10... Cut and raise, 12... Annular lip. Figure l Figure 7 Figure 2

Claims (1)

[Claims] In a magnetron, an annular permanent magnet is attached to the end of the anode cylinder of the magnetron body, and a spiral fin is attached around the anode cylinder, and a yoke is provided surrounding the outside of these in a frame shape. The yoke is provided with an annular rib that is concentric with the hole and protrudes on the inner surface of the yoke around the hole for passing through the high frequency output part of the magnetron main body, and the external shape matches the annular rib and the high frequency output part is formed in the center of the yoke. A positioning plate with a center hole of approximately the same diameter as the yoke on the high frequency output side and a part of the periphery thereof cut and raised so as to close the gap between the yoke and the spiral fin at the corner of the frame-shaped yoke. Sandwiched between permanent magnets,
A maknetron characterized in that the high frequency output part is fitted into the center hole, and the relative positions of the magnetron main body and the yoke are fixed by a positioning plate.