JPH04308632A - Magnetron - Google Patents

Abstract

PURPOSE:To provide a magnetron having good radiation characteristics with which removal of radiators is less likely to occur by jointing vanes of Cu on the inner side of an anode cylinder so as to achieve joint or adhesion of a good reliability of Al with each other in using the radiators of Al which leads to a good conductivity from the vanes to the radiators. CONSTITUTION:A magnetron is composed of an inclined function material in which inclusions of Cu 33a positioned on the inner side and Al 33b positioned on the outer side in an anode cylinder 33 are gradually changed to achieve a desired purpose.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] This invention relates to a magnetron.
In particular, it relates to improvements in the material of the anode cylinder.

0002

2. Description of the Related Art The main parts of a magnetron for a microwave oven have conventionally generally been constructed as shown in FIG. In the figure, reference numeral 11 is the oscillation unit main body, 12 is the anode cylinder, 13 is a plurality of anode vanes constituting a part of the cavity resonator, 14 is a strap ring, 15 is a filament cathode, and 16
, 16 are its end shields, 17 and 18 are anode cylinders 1
2 is a pole piece fixed to the open end of 2, 19 is a cylindrical metal container, 20 is a high frequency output part, 21 is an output part ceramic cylinder, 22 is an output tip sealing ring, and 23 is hermetically sealed thereto. metal exhaust pipe, 24 is an output metal cap, 2
5 represents an output antenna lead, one end of which 2
5a is electrically connected to one of the vanes 13, passes through the through hole 17a of the pole piece 17, penetrates the metal container 19 and the ceramic cylinder 21, and the tip 25b is clamped by the metal exhaust pipe 23 to create an airtight state. It has been sealed.

Further, reference numeral 26 represents a ring-shaped permanent magnet arranged coaxially around the outer periphery of the metal container 19, 27 represents a yoke made of ferromagnetic material, 28 represents a ferromagnetic thin plate, and 29 represents a reticular conductive gasket. ing. 30 is a metal cylinder for a first harmonic choke with a small diameter that is hermetically soldered to the lower end of the ceramic cylinder 21, and 31 is a metal cylinder for a second harmonic choke that is hermetically soldered to its outer periphery. Further, it is hermetically soldered to the tip of the metal container 19, and the tip 31a serves as a gasket receiving ring for holding the inner peripheral portion of the conductive gasket 29. Furthermore, a radiator 32 is provided on the outer periphery of the anode cylinder 12.
The inner peripheral ends of the many cooling fins that make up the cooling fins are press-fitted and fixed.
Its outer peripheral end is fixed to the inner surface of the yoke 27.

0004

However, in the conventional structure described above, the anode cylinder 12 is usually made of Cu and the radiator 32 is made of Al. Therefore, when used for a long time, the anode cylinder 12 and the radiator 3 will have different coefficients of thermal expansion.
2, the heat dissipation effect is impaired, and the radiator
There is also a possibility that the data 32 may fall off.

The present invention has been made to solve the above-mentioned disadvantages, and an object of the present invention is to provide a magnetron that has excellent heat conductivity from the vane to the radiator and is less likely to cause the radiator to fall off.

[0006]

[Means for Solving the Problems] The present invention is a magnetron in which the anode cylinder is made of a functionally graded material in which the contents of Cu located inside and Al located outside gradually change in content.

[0007]

[Operation] According to the present invention, the anode cylinder, the vane and the radiator can be reliably joined or brought into close contact with each other, the heat conductivity from the vane to the radiator is excellent, and the radiator is unlikely to fall off. .

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings.

A microwave oven magnetron that generates a fundamental wave in the 2450 MHz band to which the present invention is applied is constructed as shown in FIG. 1, and the same parts as in the conventional example (FIG. 2) are given the same reference numerals.

That is, inside the anode cylinder 33 constituting the oscillating unit main body 11, a plurality of vanes 13 are arranged radially to form a cavity resonator. 33 will be described in detail later. The upper and lower ends of each of the vanes 13 mentioned above are connected every other by a pair of large and small strap rings 14, 14, respectively. A spiral filament cathode 15 is disposed along the axis of the anode cylinder 33 in an electron action space surrounded by free ends of a plurality of copper vanes 13, and both ends thereof are connected to end seeds.
It is fixed to the leads 16, 16. Furthermore, the anode cylinder 33
There are approximately funnel-shaped pole pieces 17, 1 at both ends of the
A cylindrical metal container 19 is also fixed to one end of the anode cylinder 33 in contact with one end of the anode cylinder 33. A second harmonic choke metal cylinder 31 having a large diameter part and a small diameter part is hermetically sealed to the upper open end of the metal container 19. In this case, the stepped portion between the large-diameter portion and the small-diameter portion is hermetically sealed to the open end of the metal container 19, and the large-diameter portion has approximately the same diameter as the metal container 19. A gasket receiving ring 31 a at the tip surrounding the lower end is in contact with the conductive gasket 29 . Further, the small diameter portion is disposed inside the metal container 19 coaxially and extending in the vane direction. Inside this second harmonic choke metal cylinder 31, a first harmonic choke metal cylinder 30 having a small diameter and the innermost side is placed inside the second harmonic choke metal cylinder 31. 31 and the metal container 19 coaxially, and soldered to the lower end of the ceramic cylinder 21 . A retaining ring 22 is hermetically sealed to the upper end surface of the ceramic cylinder 21 . An output metal cap 24 is fixed to the side surface of the retaining ring 22, and a metal exhaust pipe 23 is hermetically sealed and held at the inner bent portion of the retaining ring 22. Further, one end 25a of an antenna lead 25 is electrically connected to one of the vanes 13, and this antenna lead 25 passes through the through hole 17a of the pole piece 17 and extends along the tube axis. It extends inside the output section 20, and the other end 25b is clamped and fixed to the exhaust pipe 23.

Furthermore, a permanent magnet 26 whose inner surface is tapered on the lower side is provided on the outer periphery of the metal container 19, and an aluminum magnet 26 with a large number of cooling fins fitted on the outer periphery of the anode cylinder 33 is provided.
A manufactured radiator 32 is provided. These permanent magnets 2
6, surrounding the anode cylinder 12, radiator 32, etc.
A frame-like yoke 27 is provided. This frame-shaped yoke 27
A metal cylinder 3 for the second harmonic choke is placed in the center opening of the
A conductive gasket 29 is provided between the gasket receiving ring 31a, which is the tip of the conductive gasket 29. One surface of the permanent magnet 26 is in contact with the frame-shaped yoke 27 and the conductive gasket 29 via the magnetically conductive plate 28, and the other surface is in contact with the protrusion of the metal container 19.

Now, the anode cylinder 33 will be explained in detail.
In the anode cylinder 33 of the present invention, Cu 33a is located inside, Al 33b is located outside, and Cu and A are located inside in the middle.
1 is composed of a functionally gradient material whose content gradually changes. Here, to explain about functionally graded materials, generally when two materials A and B are joined together, the advantages of both can be utilized, but the disadvantage is that they are easily bent or peeled off due to the difference in coefficient of thermal expansion. However, the functionally graded material gradually changes the material quality from A to B at the intermediate interface to solve the above-mentioned difficulties. The details are introduced, for example, in the magazine "Industrial Materials", Vol. 38, No. 12 and No. 14 (published October 1990 and November 1990).

[0013]

According to the present invention, the anode cylinder is made of a functionally graded material in which the content of Cu on the inside and Al on the outside gradually changes. Can reliably join manufactured vanes. Furthermore, when using a radiator made of Al, reliable bonding or close contact between Al can be achieved. Therefore, the heat conductivity from the vane to the radiator is good, so the heat dissipation characteristics are excellent.
The radiator is also less likely to fall off.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing a magnetron according to an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view showing a conventional magnetron.

[Explanation of symbols]

13...Vane, 32...Radiator, 33...Anode cylinder, 3
3a...Cu, 33b...Al.

Claims (1)

[Claims] 1. A magnetron in which a plurality of vanes are arranged radially inside an anode cylinder to constitute a cavity resonator, and a radiator is provided on the outer periphery of the anode cylinder, the anode cylinder comprising: A magnetron characterized in that Cu located on the inside and Al located on the outside are made of a functionally graded material whose content gradually changes in the middle part.