JPH031882Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of a magnetron.

Generally, as shown in FIGS. 1 and 2, in a magnetron, an output section 2 is connected to the output section of an anode cylinder 1 via a cup-shaped seal part (not shown), and an output section 2 is connected to the input side of the anode cylinder 1. An insulator 4 is sealed to the magnetron via a cup-shaped seal part 3, thereby forming the magnetron body. Further, a plurality of radiator fins 5 are fitted into the outer periphery of the anode cylinder 1, and magnets 6 and 7 are arranged at both ends of the anode cylinder 1 to form a magnetic circuit.A yoke 8 connects the magnetron body and the magnets 6 and 7. and are clamped and fixed. Also, the cup seal part 3 of the input section
A filter case 9 is forcibly fitted to prevent radio wave leakage and noise.

Now, when the magnetron having such a structure is operated, the heat generated in the magnetron main body is cooled by the radiator fin 5, but some of it is transferred to the magnet 7 from the parts attached to the main body. Although ferrite is generally used for the magnet 7 because of its low material cost, the characteristics of the ferrite magnet deteriorate as the temperature rises, leading to a decrease in the output of the microwave oven. Therefore, the problem is how to suppress the temperature rise of the magnet during operation.

However, the conventional filter case 9 is
The inner end 9a is completely attached to the cup-shaped seal component 3 by forced fitting, and the bottom surface 9b is pressed against the yoke 8, and the protrusion 9c formed on a part of the bottom surface 9b is brought into contact with the magnet 7. There is. Therefore, the heat generated in the magnetron body during operation is
It is transmitted from the end portion 9a through the protruding portion 9c to the magnet 7, as shown by reference numeral 10 in FIG. For this reason, the characteristics of the magnet 7 made of ferrite deteriorated, resulting in a disadvantage that the output of the microwave oven decreased.

The present invention was devised in view of the above-mentioned drawbacks of the prior art, and it is an object of the present invention to provide a magnetron that can prevent heat conduction to the magnet.

Hereinafter, the present invention will be explained with reference to illustrated embodiments.

FIG. 3 is a sectional view of essential parts showing an embodiment of the magnetron according to the present invention. Note that the same members as in FIG. 2 are designated by the same reference numerals and their explanations will be omitted. Bottom surface 12 of filter case 12 facing yoke 8
As for a, the inner part corresponding to the vicinity of the outer diameter of the magnet 7 maintains a gap 13 with the yoke 8, and the bottom surface 12b facing the magnet 8 similarly maintains a gap 14 with the magnet 8. Therefore, the heat generated in the main body and transmitted to the end portion 12c of the filter case 12 easily escapes to the outside of the filter case 12 through the bottom surfaces 12b and 12a. Further, as shown by reference numeral 16, the heat transmitted from the bottom surface 12a to the yoke 8 is transmitted to the portion outside the magnet 8, so that it can easily escape from the yoke 8 to the outside. Therefore, the temperature of the magnet 8 is prevented from increasing, and the output of the microwave oven does not decrease during operation.

As is clear from the above description, according to the magnetron of the present invention, the temperature of the magnet can be prevented from increasing, and the performance can be improved.

[Brief explanation of drawings]

FIG. 1 is an external view of a conventional magnetron, FIG. 2 is a sectional view of the main part of FIG. 1, and FIG. 3 is a sectional view of the main part of an embodiment of the magnetron according to the present invention. 1... Anode cylinder, 6, 7... Magnet, 8...
...Yoke, 12...Filter case, 12a,
12b...Bottom surface, 13, 14...Gap.

Claims (1)

[Scope of utility model registration request] In the magnetron, magnets arranged on both sides of the magnetron body are clamped and fixed between yokes, the inner end of the filter case is forcibly fitted to the magnetron body, and the bottom surface of the filter case is pressed against the yoke. A bottom surface of the magnetron is formed such that an inner portion of the bottom surface corresponds to the vicinity of the outer diameter of the magnet so as to maintain a gap with the yoke and the magnet.