JPH11144633A - Magnetron - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve cooling efficiency, miniaturize a device or increase the output by forming a magnetic circuit of magnets applying magnetic field to a core tube, and forming yokes surrounding and fixing them into four columns around the core tube so that the cooling air of radiating fins fixed to the core tube passes between the columns. SOLUTION: A core tube 1 serving as a vacuum tube main body for generating microwaves is provided with an output antenna 2 of microwaves at the end section, and multiple radiating fins 7 for radiating generated heat are pressed into the core tube 1. A magnetic circuit is formed with an antenna side magnet 3 and a filter side magnet 4 for applying magnetic field, and two stanchions 5-1 and two stanchions 6-1 arranged around the core tube 1 and having the width of a half or below of the width of the radiating fins 7 are fixed to filter side yokes 5 and antenna side yokes 6 surrounding the magnetic circuit. The air flow path is formed into an opened shape, not a closed cylindrical shape, thus the passing path of cooling air has an increased degree of freedom and is widened.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetron used for microwave ovens and the like for generating microwaves, and more particularly to a structure of a yoke forming a magnetic circuit.

[0002]

2. Description of the Related Art A magnetron used in a conventional microwave oven has a core tube 1 as shown in FIG.
A plurality of radiating fins 7 for radiating heat by cooling air are press-fitted around the fin. At both ends of the core tube, a pair of magnets (antenna-side magnet 3 and filter-side magnet 4) are already provided above and below. A set of yoke (antenna-side yoke 6 and filter-side yoke 5) is provided so as to surround the core tube 1, the radiation fin 7, and the magnet. Then, as shown in FIG. 3B, the shape of the yoke on the filter side is U-shaped, and the passage in the cooling diagram is a square tube.

[0003]

However, in the conventional magnetron, the yoke has a square cylindrical shape.
The cooling air cannot pass sufficiently, and the cooling effect cannot be sufficiently obtained. That is, although the flow of the cooling air is indicated by arrows in FIG. 3B, the region indicated by B in the drawing is the filter side yoke 5
There is a problem that sufficient cooling air cannot be obtained because the space between the core tube 1 and the core tube 1 is narrow, and sufficient cooling air cannot be obtained also on the leeward side because of the cylindrical surrounding.

In order to solve these problems, if the size of each yoke forming the passage of the cooling air is increased, the size of the magnetron goes against the miniaturization, and the magnetron occupies a large area when used in a microwave oven. However, there is a problem that such inconvenience occurs.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention adopts a configuration in which the configuration of the yoke is reversed from the conventional cylindrical configuration. For this reason, the yoke is formed into four pillars around the core tube so that the cooling air passes between the pillars.

According to the above configuration, the degree of freedom of the passage of the cooling air is increased and widened, and a sufficient cooling effect can be obtained.
Therefore, a sufficient cooling effect can be obtained without increasing the size of the cooling air passage, and the size of the magnetron can be reduced.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention provides a core tube as a vacuum tube main body for oscillating microwaves, and an output tube provided at one end of the core tube for outputting microwaves of the core tube. An antenna, a pair of magnets provided at both ends of the core tube to apply a magnetic field to the core tube, and a radiation fin fixed to the core tube to dissipate heat of the core tube and radiating heat by cooling air, The yoke forms a magnetic circuit of the magnet and surrounds and fixes the core tube and the magnet. The yoke is formed in four pillars around the core tube, and the cooling air flows between the pillars. Pass through.

Since the air path is not a closed cylindrical shape as in the prior art, it has an open shape, so that the degree of freedom in the passage of the cooling air is increased and the air path is widened, so that a sufficient cooling effect is obtained. can get. This also makes it possible to reduce the size of the magnetron.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1A and 1B show a magnetron according to an embodiment of the present invention. FIG. 1A is a side view, and FIG. 1B is a plan view as viewed from the antenna side.

In FIG. 1, reference numeral 1 denotes a core tube as a vacuum tube main body for generating microwaves. An antenna 2 is provided at one end of the core tube 1 for outputting microwaves from the core tube 1. ing. Reference numerals 3 and 4 denote a pair of magnets provided at both ends of the core tube 1 for applying a magnetic field to the core tube 1. An antenna-side magnet 3 and a filter-side magnet 4 are provided respectively. Further, a plurality of radiation fins 7 press-fitted into the core tube 1 are provided to dissipate the heat generated by the core tube 1. In addition, these core tube 1 and magnet 3,
There are provided two yoke which surround and fix 4 and form a magnetic circuit, that is, a filter yoke 5 and an antenna yoke 6. A filter case 8 is attached to the antenna-side yoke 6. The filter case 8 has a built-in filter circuit for suppressing generation of noise generated from the core tube 1. In particular, the magnetron of the present invention has a filter side yoke 5 and an antenna side yoke 6
Is different from that of the first embodiment. The filter-side yoke 5 and the antenna-side yoke 6 each have a total of four pillar-shaped supports 5-1 and 6 each having two of each.
-1 is provided. Four pillars 5-1 and 6-1 are arranged around the core tube 1 and
Are fixed to the yoke 5 on the filter side and the yoke 6 on the antenna side. Further, the width of the columns 5-1 and 6-1 is not increased so that the cooling air hits the radiating fins 7, but is set to be not more than 1/2 of the width of the radiating fins 7. Cooling efficiency is improved by such a configuration of the yoke. The reason will be described with reference to FIG.

FIG. 2 (a) shows a state in which the cooling air is blown from the front. Since the cooling air is open as shown by the arrow, even if the space between the support 5-1 and the core tube 1 is narrow, the air is not blown. Even if it does not reach between the support 5-1 and the core tube 1 when it hits the radiating fins 7, it escapes in front of the fins 7 and sufficiently blows the radiating fins 7 in front. In addition, since the cooling air blows from behind the support 5-1 as well, cooling efficiency is improved.

FIG. 1B shows a state in which the cooling air blows from a slant. Since the cooling air is open as shown by the arrow, the center of the cooling air hits the core tube 1 and flows on both sides,
In addition, since both ends are open, the cooling air is applied to both ends to improve the cooling efficiency.

[0014]

As described above, according to the present invention, the cooling efficiency is improved. Therefore, the size of the magnetron can be reduced.

[0015] The improvement in cooling efficiency can be achieved by increasing the output if the size is the same.

[Brief description of the drawings]

FIG. 1A is a side view of a magnetron according to an embodiment of the present invention. FIG. 1B is a plan view of the magnetron as viewed from an output antenna side.

2A is a sectional view of a main part of the magnetron. FIG. 2B is a sectional view of a main part of the magnetron.

FIG. 3A is a side view of a conventional magnetron. FIG. 3B is a sectional view of a main part of the magnetron.

[Explanation of symbols]

 Reference Signs List 1 core tube 2 output antenna 3 antenna side magnet 4 filter side magnet 5 filter side yoke 6 antenna side yoke 7 radiation fin 8 filter case

Claims (1)

[Claims] 1. A core tube as a vacuum tube main body for oscillating microwaves, an output antenna provided at one end of the core tube for outputting microwaves of the core tube, and the core tube Forming a pair of magnets provided at both ends of the core tube to apply a magnetic field to the core tube, radiation fins fixed to the core tube to dissipate heat of the core tube, and radiating heat by cooling air, and a magnetic circuit of the magnet And a yoke that surrounds and fixes the core tube and the magnet, and a side portion of the yoke corresponding to the radiating fin is formed into four pillars around the core tube, and is formed between the pillars. Magnetron with cooling air passing through it.