JPS6026439Y2 - magnetron - Google Patents

Description

[Detailed explanation of the idea] This idea concerns improvements to magnetrons.

Recently, magnetrons have been widely used in microwave ovens.
Recently, it has been desired to make this type of microwave oven magnetron more compact, and for this reason, the arrangement of the permanent magnets has been devised.

However, when a permanent magnet is disposed close to the cathode body in a vacuum region, a decrease in magnetic force due to temperature rise is unavoidable.

This invention was made in view of the above circumstances, and the purpose is to provide a magnetron in which the heat dissipation effect of a permanent magnet is improved.

Hereinafter, one embodiment of this invention will be described in detail with reference to the drawings.

The magnetron of this invention is constructed as shown in FIG.

That is, an oscillating section main body 2 is tightly fixed inside a magnetic cylinder 1 made of Fe (iron), etc., and a radiator 3 consisting of a plurality of fins is fixed to the outer periphery of the magnetic cylinder 1.

The magnetic cylinder 1 is made by drawing, has a seamless bottomed cylinder shape, and has a through hole 4 bored in its side wall, and an output portion 5 protrudes from the through hole 4 .

Further, a sealing body 6 made of a magnetic material is hermetically sealed in the opening of the magnetic cylinder 1, and the inside is a vacuum region.

In other words, the magnetic cylinder 1 and the sealed body 6 form a vacuum envelope.

On the main body of the oscillating section, a plurality of anode vanes 8 and a cathode body 9 are arranged inside a cylindrical anode body 7 made of a non-magnetic material such as Cu (copper).

In this case, the length of the cylindrical anode body 7 and the width of the anode vane 8 are set to be the same.

Further, the anode vanes 8 are connected by a strap 10, and an antenna conductor 12 is fixed to one of the anode vanes 8, and this antenna conductor 12 passes through the through hole 4 of the magnetic cylinder 1 and connects to the output part 5. Located within.

Further, permanent magnets 13 are provided on both sides of the anode vane 8, respectively.
．． 14 is arranged coaxially with the cylindrical anode body 7, and each side is in close contact with the bottom of the magnetic cylinder 1 and the sealing body 6.

In this case, the permanent magnets 13 and 14 are cylindrical.

Further, a cathode stem 1 is attached to the end of one permanent magnet 14.
A cathode support 16 and 17 for supporting and energizing the cathode body 9 is drawn out through the cathode stem 15 and the sealing body 6 and through the permanent magnet 14. .

A filter element (not shown) is connected to this cathode support 16,17.

The cathode supports 16 and 17 and the filter element are housed in a filter box (not shown) fitted around the outer periphery of the opening of the magnetic cylinder 1.

Note that 18 and 19 are an upper end hat and a lower end hat, respectively, to which the cathode supports 16 and 17 are fixed.

Further, in this invention, an exhaust pipe 20 whose outer diameter corresponds to the inner diameter of the permanent magnet 13 is press-fitted into the permanent magnet 13 through the bottom of the magnetic cylinder 1 .

In this case, the exhaust pipe 20 is a good thermal conductor with better thermal conductivity than the permanent magnet 13.

A radiator 21 consisting of a plurality of fins is fixed to the outer periphery of the exhaust pipe 20.

In this case, the exhaust pipe 20 and the magnetic cylinder 1 may be fixed by soldering or the like for vacuum tightness.

The magnetron of this invention is constructed as described above and shown in the drawings, and the exhaust pipe 2-0 having the radiator 21 is press-fitted into the permanent magnet 13, so an excellent heat dissipation effect is obtained, and the permanent magnet 13 The temperature is kept low.

Generally, the permanent magnet 13 is demagnetized at high temperatures, so the exhaust pipe 2
The characteristics of the magnetron due to zero are well stabilized.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing a magnetron according to an embodiment of this invention. 1... Magnetic cylinder (vacuum envelope), 2...
...Oscillator main body, 13.14...Permanent magnet, 2
0...exhaust pipe, 21...radiator.

Claims (1)

[Scope of utility model registration request] In a magnetron in which a cylindrical permanent magnet is disposed within a vacuum envelope made of a magnetic material constituting a magnetic path, an exhaust pipe made of a good thermal conductor is in contact with the inner surface of the permanent magnet, and the outer peripheral wall of the exhaust pipe is in contact with the inner surface of the permanent magnet. A portion of the magnetron is hermetically sealed to the vacuum envelope, and a radiator is attached to a portion extending outside the vacuum envelope.