JPS59688Y2 - mcnetron - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to magnetrons, and particularly to improvements in magnetrons.

In general, magnetrons are widely used for heating or defrosting foods by being attached to microwave ovens or defrosting machines because they efficiently generate high-frequency output.

FIG. 1 is a cross-sectional view showing an example of a conventional magnetron. In the figure, 1 is an anode cylinder made of oxygen-free copper, for example, and has a plurality of radially divided anodes on its inner surface. A vane 2 forming a resonant cavity is provided, and the anode cylinder 1 and the vane 2 constitute an anode 3.

A working space 4 formed by the tips of a plurality of vanes 2 is formed on the central axis of the anode 3, and inside this working space 4, a heating element such as thorium tungsten or the like is formed in a spiral shape. An electron emitting cathode 5 is arranged.

In this case, a working space 4 with a predetermined distance is formed between the thermionic emission cathode 5 and the tip of the vane 2 .

Further, 6 and 7 are end shields arranged at both ends of the thermionic emission cathode 5, respectively, to prevent electrons from deviating in the direction of the central axis.

Furthermore, side supports 8a, 8b and a center support 8C are fixed to the bottom surface of the end shield 7, respectively, to fixedly support the thermionic emission cathode 5 and supply operating current.

The other end sides of these side supports 8a, 8b and center support 8C extend outward.

Moreover, cone-shaped magnetic poles 9, 1 are provided at both ends of the anode cylinder 1.
0 are fixedly arranged, respectively, and form a magnetic path that converges a uniform magnetic flux within the working space 4.

Furthermore, vacuum sealing members 11 and 12 made of, for example, iron are provided on the outer surfaces of the cone-shaped magnetic poles 9 and 10 to vacuum-seal the inside of the anode cylinder 1, respectively. This vacuum sealing member 1 is fixedly arranged by welding.
Cylindrical permanent magnets 13 and 14 are arranged in close contact with the outer surfaces of magnets 1 and 12, respectively.

Further, a lock-shaped choke 15 for preventing noise leakage is fixed to the inner surface of the vacuum sealing member 11, and an output side insulator 16 formed in a cylindrical shape made of ceramic or the like is fixed to the outer surface of the choke. It is connected.

An exhaust pipe 17 made of a copper pipe is fixed to the tip of the output insulator 16, and the exhaust pipe 17 is hermetically welded to an antenna conductor 18 connected to one end of the vane 2.

Furthermore, the outer surface of the exhaust pipe 17 is covered with a metal cover 19, which protects the press-contact portion of the exhaust pipe 17, prevents sparks due to electric field concentration, and functions as a high-frequency antenna.
High frequency output is taken out from this metal cover 19 to the outside.

Furthermore, a plurality of aluminum heat sinks 20 extending in the tube diameter direction are fitted onto the outer peripheral surface of the anode cylinder 1, and are covered with the outer peripheral surfaces of the permanent magnets 13 and 14 by a yoke 21 for forming a magnetic path. It is being said.

Further, a gasket 22 formed of metal netting or the like to prevent radio wave leakage is arranged on the outer surface of the permanent magnet 13, and this gasket 22 is attached to the gasket receiver 2 to prevent it from falling off.
3 is held and fixed between the end of the yoke 21 and the outer peripheral surface of the vacuum sealing member 11.

In the magnetron configured in this way, a side support (which also serves as a lead wire) is connected to an external terminal (not shown).
When input is supplied between a, 8b and center support 8C, the thermionic emission cathode 5 is heated, and when a predetermined voltage is supplied to the anode 3, thermionic emission cathode 5 emits thermoelectrons. Ru.

These thermoelectrons act within the magnetic field of the magnetic poles 9 and 10 to generate high frequency oscillation, and the output is radiated through the antenna conductor 18 into the oven of a microwave oven, for example.

However, in the magnetron having the above configuration, the anode cylinder 1 is formed of copper material, while the vacuum sealing members 11 and 12 are formed of iron material. The outer circumferential ends of vacuum sealing members 11 and 12 are fixed to both ends of the vacuum sealing members 11 and 12 by arc welding.

However, in such a welded structure, as shown in the phase diagram in Figure 2, it is difficult to create an alloy using only steel and iron, so only the extremely thin part at the tip of the joint between copper and iron is welded. become.

As a result, pinholes or cracks are likely to occur in this welded part, and the anode cylinder is damaged due to poor welding.
It has disadvantages such as the inability to keep the inside vacuum-tight.

As an attempt to solve this problem of weldability, a magnetron with a sealing structure using Kovar material with high weldability for the vacuum sealing members 11 and 12 has been proposed.
Kovar material has drawbacks such as extremely high cost.

Therefore, an object of the present invention has been made with attention to the above points, and is to provide a highly reliable magnetron that is inexpensive, has high weldability, and does not generate cracks or pinholes.

In order to achieve this objective, the magnetron according to the present invention has an anode cylinder and a vacuum sealing member made of the same metal member.

The magnetron according to the present invention will be described in detail below with reference to the drawings.

FIG. 3 is a sectional view of a main part of an embodiment of the magnetron according to the present invention, and since the same symbols as those in FIG. 1 represent the same elements, a description thereof will be omitted.

In the figure, an anode cylinder 24 and a vacuum sealing member 25,
26 is formed by molding aluminum metal, and
Aluminum, which is the same metal, is welded to the welded portion to hermetically seal the inside of the anode cylinder 24.

In the magnetron configured in this manner, the welding parts between the anode cylinder 24 and the vacuum sealing members 25 and 26 are made of the same metal material, which makes welding work extremely easy and greatly improves welding performance. As a result, there were no cracks or pinholes in the welded area.

In addition, since the anode cylinder 24 and the vacuum sealing members 25 and 26 are made of aluminum metal, press molding is relatively easy, and the magnetron body is lightweight.
Furthermore, since aluminum metal is a non-magnetic material, magnetic leakage from externally disposed permanent magnets 14 and 15 can be reduced, and the size of the permanent magnets can be reduced.

In addition, in the magnetron according to the present invention shown in FIG. 22 is held and fixed.

According to such a configuration, when the gasket 22 is attached to a waveguide (not shown), the gasket 22 may be deformed inward (collapsed) and the gasket 22 may come off due to the fitted state of the yoke 21 and the gasket 22 due to component dimensional tolerances. We were able to further improve the radio wave leakage prevention effect.

As explained above, according to the magnetron of the present invention, welding work becomes extremely easy, welding performance is greatly improved, there are no cracks or pinholes in the welded part, and quality and reliability are greatly improved. can be improved.

Furthermore, extremely excellent effects such as significantly lower production costs and parts unit prices can be obtained.

[Brief explanation of the drawing]

Figure 1 is a sectional view of the main parts of an example of a conventional magnetron.
FIG. 2 is a state diagram, and FIG. 3 is a sectional view of essential parts showing an example of the magnetron according to the present invention. 1... Anode cylinder, 1a... End part, 2...
...Bane, 3... Anode, 4...
・Working space, 5...Cathode, 6,7...
End shield, 8a, 8b...Side support, 8C...Center support), 9.10.
...Magnetic pole, 11.12...Vacuum sealing member, 13.14...Permanent magnet, 15...
Choke, 16... Output side insulator, 17...
... Exhaust pipe, 18 ... Antenna conductor, 19.
...Metal cover, 20... Heat sink, 21
... Yoke, 22 ... Gasket, 2
3...Gasket receiver, 24...Anode cylinder, 25.26...Vacuum sealing member, 27...
...Gasket receiver.

Claims (1)

[Scope of utility model registration request] A cylindrical anode having a plurality of vanes arranged radially around the cathode, magnetic poles arranged at both ends of the anode and guiding magnetic flux of a permanent magnet to the center of the anode, and both ends of the magnetic pole. 1. A magnetron comprising at least a vacuum sealing member disposed in the anode and vacuum sealing the inside of the anode, characterized in that the anode and the vacuum sealing member are formed in combination of the same aluminum material.