JPS60160542A - Method for manufacture anode structure of magnetron - Google Patents

Abstract

PURPOSE:To enable to easily and surely weld a strap ring to a vane by restraining at least a joining portion at the outer periphery of an inner strap ring with the tapered surface of a restraining member which has a tapered surface. CONSTITUTION:A stopper 6 is fitted into the top surface of a vane 3 and an inner strap ring 4 is restrained by fitting the tapered surface 7a of a restraining ring 7 which has a tapered surface 7a at the inner surface, into the outer periphery of the inner strap ring 4 and, in this state, a joining portion between the vane 3 and the inner strap ring 4 is spot-welded. Thus, since the inner strap ring 4 is restrained by the restraining ring 7, the expansion of the inner strap ring 4 caused by temperature rise due to heating in welding is restrained and therefore a space between the inner strap ring 4 and the vane 3 is extremely reduced and it is possible to carry out good welding without disturbing the shape.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a method for manufacturing a magnetron anode structure, and particularly to a method for joining vanes and strap rings.

[Background of the invention]

Conventionally, the magnetron anode structure that has been widely used is
It consists of the structure shown in the figure. The anode 1 consists of an anode cylinder 2 and a plurality of vanes 3 which are provided radially on the inner wall of the anode cylinder 2 and form a resonant cavity together with the anode cylinder 2. Every other inner strap ring 4 and outer strap ring 5 are electrically connected.

The anode 1 is manufactured by hobbing a billet of oxygen-free copper, integrally molding the anode cylinder 2 and the vane 3, filling the space between the vanes 3 with resin, etc., and lathe-processing the anode into a substantially rectangular shape n3a. They are formed at the upper and lower ends in the axial direction of the cylinder. The resin is then removed.

The strap ring 4.5 is manufactured by press punching a plate of oxygen-free copper or the like to form the inner and outer strap ring 4.5.
5 is molded at the same time. Next these strap rings 4
．． Silver plating is applied to 5.

Anode 1 and strap ring 4 manufactured in this way
．． 5 is assembled by driving the protrusions 4a and 5a of the strap ring 4.5 into the middle of the groove 3a of the vane 3 with a slight interference, and placing it in a reducing atmosphere furnace at approximately 800°C to coat the silver plating layer, the vane 3 and It is fixed to the copper material of the strap ring 4.5 by forming a silver-copper solder.

However, such silver-copper brazing requires expensive silver and an atmosphere furnace to heat the entire anode 1, so that the vane 3 and the strap ring 4 are directly connected to each other.
．． It is possible to weld 5. Furthermore, if the anode 1 is replaced with aluminum in order to save material costs, it will be difficult to braze the strap ring 4.5, so direct welding is also desirable in this case.

Therefore, when welding the strap ring 4.5 directly to the vane 3, for example by electron beam, laser, micro plasma, etc., the temperature of the inner strap ring 4 and the vane 3 will rise due to heating during welding. As shown in FIG. 1(b), the inner strap ring 4 moves in the direction of the arrow a, and the vane 3 moves in the direction of the arrow a, resulting in a gap and a situation where welding is not possible. This phenomenon causes the strap ring 4.5, which has a smaller heat capacity than the vane 3, to move more in direction than the vane 3.

If we forcibly weld something with a gap between the strap ring 4 and the vane 3 in this way, as shown in Figure 2, the protrusion 4a of the strap ring 4 and the vane 3 will be melted more than necessary, resulting in a disordered shape. As a result, the stable operation of the magnetron will be significantly reduced.

[Purpose of the invention]

An object of the present invention is to provide a method for manufacturing a magnetron anode structure that allows easy and reliable welding of a strap ring and a vane.

[Summary of the invention]

In order to achieve the above object, the present invention suppresses at least the joint portion of the outer periphery of the inner strap ring with a tapered surface of a restraining member having a tapered surface, and spot welds the joint portion of the vane groove and the inner strap ring. Features.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIG. Note that the same members and portions as in FIG. 1 are designated by the same reference numerals, and their explanations will be omitted. Fit the EC stopper 6 on the tip end face of the vane 3, and fit the tapered surface 7a of the restraining ring 7, which has an inner tapered surface 7a, onto the outer periphery of the inner strap ring 4 to restrain the inner strap ring 4. In this state, the vane 3 and the inner strap spring 4 were spot welded.

Since the inner strap ring 4 is held down by the restraining ring 7 in this way, the expansion of the inner strap ring 4 caused by the temperature rise due to heating during welding is suppressed, and the gap between the inner strap ring 4 and the vane 3 is greatly reduced. ζ is reduced, allowing for good welding without disturbing the shape.

As a result of experiments, stopper 6 that suppresses the protrusion of vane 3
Since there was no noticeable difference even if it was not used, it may be used as necessary depending on the dimensions of the groove 3a of the vane 3.

FIG. 4 shows another embodiment of the invention. In the above embodiment, the entire inner strap ring 4 was held down by the holding ring 7, but in this example, the inner strap ring 4 is held down locally at each joining point using a claw-shaped holding projection 8 having a tapered surface 8a, and spot welding is performed. do. This method also provides the same effects as those of the embodiments described above. Either this method or the method of the above example is used.
The most efficient method should be selected in consideration of the welding equipment.

As for the material of the restraining ring 7 and the restraining protrusion 8, good results were obtained with either ceramic, which has low thermal expansion, or material with a relatively large heat capacity, such as metal. Practically speaking, it is best to use a material such as stainless steel, which has excellent corrosion resistance, excellent mechanical strength, and is resistant to deformation. However, if the welding method is electron beam or laser, either metal or nonmetal may be used, but if microplasma or arc welding, it must be nonmetallic.

〔Effect of the invention〕

According to the invention, for welding the inner strap ring,
Since it is possible to prevent the phenomenon of separation from the vane due to thermal expansion, a stable and highly reliable bonding state can be obtained, and there is no need for expensive brazing materials such as silver, and the anode material is also inexpensive. This has many benefits, including the ability to reduce material costs by using aluminum.

[Brief explanation of the drawing]

FIG. 1 shows a conventional magnetron anode structure. (a) is a plan view, (bl is A-A in (a), @ enlarged cross-sectional view, Figure 2 is an explanatory cross-sectional view of the defective state that occurred in Figure 1,
FIG. 3 is a sectional view of a main part of a magnetron anode structure showing one embodiment of the present invention, and FIG. 4 is a sectional view of a main part of a magnetron anode structure showing another embodiment of the invention. 1...Anode, 2...Anode cylinder, 3...Vane. 3a...Groove, 4...Inner strap ring, butt...
Outer strap ring, 7...retainer ring, 8...
Holding protrusion. Figure 1 (0)

Claims (1)

[Claims] A plurality of vanes are provided radially on the inner wall of the anode cylinder, and every other double large and small inner strap ring and outer strap ring are electrically connected in the groove formed at the end of the vane in the axial direction of the cylinder. In the method for manufacturing a magnetron anode structure, at least the joint portion of the outer circumference of the inner strap ring is held down by a tapered surface of a restraining member having a tapered surface, and the joint portion of the groove of the vane and the inner strap ring are spot welded. A method for manufacturing a magnetron anode structure, characterized by: