JPS60154434A - Magnetron - Google Patents

Abstract

PURPOSE:To accomplish both material cost reduction and high reliability, by making an anode cylinder and a vane of aluminum or its alloy and sealing parts of Ni-clad iron plate. CONSTITUTION:An anode cylinder 1 and a vane 2 are made of aluminum or its alloy, and sealing parts 8 and 20 are made of Ni-clad iron plate. Adopting Ni- clad iron plate easily makes it possible to obtain a nickel layer of 100-200mum or thicker. And further the layer is uniform, and particularly fine compared with plated nickel layers. Accordingly, if the sealing parts 8 and 20 made of Ni-clad iron plate are welded on the anode cylinder 1 made of Al, a junctio whose property is same as if the seal parts 8 and 20 were integrated parts of nickel plate can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a magnetron, and particularly to a magnetron structure suitable for reducing costs by using aluminum or an aluminum-based alloy as the material for the anode cylinder and vane. .

[Background of the invention]

A magnetron that has been widely used in the past has a structure as shown in FIG. There is an anode circle 1 on the inner wall of the anode cylinder l.
A plurality of vanes 2 are provided radially, which together form a resonant cavity, and these vanes 2 are connected to a double strap ring 3.
．． 4, every other board is electrically connected. An antenna 5 for propagating microwaves is installed in an arbitrary one of the vanes 2. Further, a pair of upper and lower magnetic poles 6.7 are arranged at both ends of the anode cylinder 1.

A cup-shaped seal component 8 whose one end is joined to the end of the anode cylinder 1 by welding or the like is disposed on the upper magnetic pole 6, and the seal component 8 includes an output ceramic 9 that serves as a microwave emission window. Furthermore, an exhaust pipe 10 is brazed to the output ceramic 9. After exhaustion is completed, the exhaust pipe 10 is pressed together with the antenna 5 and tipped off, and an exhaust pipe cover 11 that protects the tipped-off portion is covered.

A cathode filament 12 made of a thorium tungsten wire or the like that emits thermoelectrons is disposed at the center of the tube axis of the anode cylinder 1, and the cathode filament 12 is supported by a cathode stem structure.

That is, the cathode filament 12 is connected to a pair of upper and lower end shields 13.1 that prevent thermoelectrons from escaping in the tube axis direction.
41 are sandwiched, and these pair of upper and lower end shields 1
3.14 is held by a pair of leads 15 and 16, and a pair of leads 15 and 16 are passed through the stem ceramic 17 and are sealed together with terminals 18 and 19 by brazing to the stem ceramic 17. The stem ceramic 17 is brazed to one end of a cup-shaped seal component 20 disposed on the lower magnetic pole 7, and the other end of the seal component 20 is joined to the end of the anode cylinder 1 by welding or the like. It is sealed.

In a magnetron having such a configuration, oxygen-free copper is generally used as the material for the anode cylinder 1 and the vane 2, but this material accounts for a large proportion, and in order to reduce the cost of the magnetron, the anode cylinder 1 and the vane 2 must be made of oxygen-free copper. It is preferable to use aluminum or an aluminum alloy.

By the way, in order to silver-braze the seal parts 8.20 to the output and stem ceramics 9.17, Ni plating is applied to a mild steel plate, Furniture, or Kovar, etc., which is suitable for silver brazing with the ceramics 9.17. A highly reliable product with good welding to the steel material of the anode cylinder 1 can be obtained.

Therefore, in order to reduce costs, we consider the case where the anode cylinder 1 is made of aluminum or an aluminum alloy.
It is relatively easy to fit in with the Ni-plated surface of the sealing part 8.18 which has been plated with NiA4. It produces an extremely thin layer of intermetallic compounds such as, and welding is possible. However, in normal Ni plating, the thickness of the plating is 5 to 15 μm, so local variations in the intermetallic compound between Ni and A1 occur, causing cracks, etc., making 100% vacuum-tight welding difficult. It is.

Eliminate CI>6* points; S tc 4i 'i -'v
Parts 8 and 20 Ni plating applied to 4° 100-200
It is sufficient to have a sufficient thickness of approximately μm, but applying such a thick layer increases the number of man-hours, and the thicker the layer, the more difficult it is to generate a uniform plating layer, and the layer itself is porous and plated. It contains many impurities in the liquid, and gas generation during welding (so-called blowholes) makes it difficult to obtain a good bond.

Therefore, it is possible to use a Ni plate or an i plate for the entire sealing part 8.2o, but the former increases the material cost and offsets the material cost savings of using Al for the anode cylinder 1, and the latter has an impact on strength. The problem is that it has to be made thicker and it is difficult to join it to the ceramic parts 9.17.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a magnetron in which high reliability can be obtained even when the anode cylinder and vane are made of aluminum or an aluminum alloy to reduce material costs.

[Summary of the invention]

In order to achieve the above object, the present invention is characterized in that the anode cylinder and the vane are made of aluminum or an aluminum alloy, and the seal part is made of a nickel-clad iron plate.

[Embodiments of the invention]

An embodiment of the present invention will be described below. Anode cylinder 1
The vane 2 is made of aluminum or an aluminum alloy, and the sealing part 8.20 is made of a nickel-clad iron plate.

Generally available commercially available nickel-clad iron plates are available with Ni cladding applied to both sides or one side, and even those with Ni cladding applied to both sides are made in various ways, such as those with cladding layers.

For welding, it is sufficient to clad only the outer circumferential side of the seal part 8.20 with nickel, but from the viewpoint of the amount of gas released in the pipe, it is better to clad both sides of the part to prevent rust. In any case, with the nickel-clad iron plate, a nickel layer of 100 to 200 μm or more can be freely obtained, and the layer is uniform and much denser than plating. For this reason, the anode cylinder 1 made of aluminum
When the seal part 8.20 made of a nickel-clad iron plate is welded to the seal part 8.20, a joint of the same quality as if the seal part 8.20 were made of an integral nickel plate is obtained.

Of course, it is also possible to use a single-sided nickel-clad iron plate and apply a thin electroplating to the entire surface so that the aluminum material in the anode is bonded to the nickel-clad surface.

〔Effect of the invention〕

As is clear from the explanatory power of the following, according to the present invention,
Since the anode cylinder and vane are made of aluminum or an aluminum-based alloy, material costs are reduced, and since the seal component is made of a nickel-clad iron plate, it can be joined with high reliability to the anode cylinder made of aluminum or an aluminum-based alloy.

[Brief explanation of the drawing]

The figure is a sectional view showing an example of a tube body of a magnetron. ■... Anode cylinder, 2... Vane, 5... Antenna, 8... Seal component, 9... Output ceramic, 10... Exhaust pipe, 12... Cathode filament, 13, 14 ...End Shield, 15.16・
... Lead, 17... Stem ceramic, 18.
19...Terminal, 20...Seal parts.

Claims (1)

[Claims] In the magnetron, the magnetron includes an anode cylinder, a plurality of vanes provided on the inner wall of the anode cylinder, and sealing parts joined to both ends of the anode cylinder to vacuum-seal an output part and a cathode stem groove body, respectively. and the vane is made of aluminum or an aluminum-based alloy, and the seal part is made of a two-dimensional steel plate.