JPS6034779B2 - Manufacturing method of magnetron anode - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a magnetron anode.

In microwave oven magnetrons, thick-walled copper (Cu) is used as the anode cylinder.This is generally done by cutting the largest cylindrical material to the required length, and shaping the inner and outer surfaces and both opening ends into a predetermined shape. It is formed by processing such as cutting.

However, processing from such a cylindrical material is
It takes a lot of labor to manufacture the cylindrical material itself, and if the dimensional accuracy of the cylindrical material is low, it has to be finished to the outer dimensions required for magnetron anodes, which results in an undesirable increase in product price. The current situation is that it is high. Therefore, it has already been proposed to form an anode for a magnetron into a cylindrical shape by rounding a flat material and butt-joining both ends. It is extremely effective in reducing product costs because it is possible to make the cylinder diameter and control the plate thickness at the same time during rounding.

For example, JP-A No. 48-90464, Utility Model Application No. 49-Sho.
-1165 small issue, Utsukai Showa 49-67545, Utsukai Showa 5
0-157854, Utility Model Application Publication No. 157855, Utility Model Application Publication No. 1977-121160, and USP 4,16
It is disclosed in the specification of No. 3,921 and the like. The present invention basically uses the above-mentioned rounding technique, but it also provides a method for manufacturing a magnetron anode that can maintain reliability and desired characteristics as a magnetron anode, especially in mass production. It provides:

Examples will be described below with reference to the drawings. Note that the same parts are represented by the same symbols. As shown in FIGS. 1 to 3, first, a rolled copper (Cu) plate is cut into a predetermined length to produce a flat material 11 shown in FIG. 1A.

This is rolled into a cylinder shape as shown in the opening in Figure 1 using an appropriate mechanical tool. Then, the opposing end faces of both ends 12 that are butted against each other along the axis are removed from burrs and cleaned with Triclean or Freon. The abutted portions of both ends 12 are made to be in close contact with each other. Next, the width corresponds to the wall thickness of the cylinder, the length corresponds to the axial length, and the thickness is, for example, 0.2 to 0.3 ribs.
Nj) Sandwich the foil 13 between both ends 12 as shown in FIG. At this time, the core metal is placed in the cylinder, the abutting portions at both ends are slightly opened, the Ni plate 13 is inserted, and the core metal is pulled out so that it can be clamped by the elasticity of the cylinder.
Then, in a vacuum or inert gas atmosphere, arrow 14,
A laser beam is applied to the Ni thin plate as shown in 14.
Locally melt the thin plate and the Cu cylinders on both sides thereof. The Ni plate is locally heated to a state where it is completely melted and then cooled to obtain an anode cylinder 10 that is tightly bonded in vacuum. Observing the cross section of the joint of the anode cylinder 10 made in this way, as shown in FIG. It becomes an alloy (diffusion bonding) layer with a ratio of about 50:50, and on both sides there is an intermediate (diffusion bonding) layer 17 in which the ratio of Cu gradually increases, and a physically and mechanically stable state of the diffusion bonding layer is obtained. .

According to experiments conducted by the present inventors, the intervening metal plate is made of a metal different from that of the anode material, and in addition to Ni, silver (
It has been found that one selected from among Ag), gold (Au), and stainless steel (SUS), or an alloy mainly composed of these, can be sufficiently put to practical use.

The above-described diffusion bonded portion of the anode cylinder with a dissimilar metal has a mechanical strength stronger than that of the material portion of the cylinder.

Therefore, according to the present invention, since this joint exists along the axial direction of the cylinder, deformation of the cylinder is reduced, and in particular, even when the inside is evacuated as a magnetron, the central part of the anode cylinder will be shaped like a pincushion at atmospheric pressure. It also reduces the possibility of denting. Therefore, as shown in FIG. 4, the anode cylinder 10 is provided with a plurality of joint parts 15, 15, . You may also do so.

In this case, the material 11 is divided into three parts, which are formed by bending a flat material into an arc shape as shown in the figure. This further increases the strength of the anode cylinder and reduces deformation due to atmospheric pressure and the like. As shown in FIG. 5, the joint may be formed by forming step-like notches 19 on the outside of both ends 12 of the material 11, so that a portion of the molten metal at the joint flows into the notches 19. There is almost no possibility that the radiator will accumulate in the outer periphery of the anode cylinder and protrude from the outer periphery of the anode cylinder, and the radiator can be press-fitted onto the outer periphery of the anode without any problem.

Moreover, this reduces the dimension in the thickness direction for diffusion bonding, making bonding easier. Further, the shape of the notch 19 may be formed into a tapered shape as shown in FIG. Note that these notches may be formed inside the cylinder. As described above, according to the present invention, a magnetron anode with excellent vacuum tightness and mechanical strength can be obtained, and it is also effective in reducing product costs and mass production.

[Brief explanation of the drawing]

Figure 1A is a perspective view of a material showing one embodiment of the present invention;
The figure opening is a perspective view of the rounded molded product, FIG. 2 is a cross-sectional view of the main part showing the joint, FIG. 3 is an enlarged cross-sectional view schematically showing the state of the joint, and FIG. A cross-sectional view showing an example of
FIGS. 5 and 6 are cross-sectional views of main parts showing still other embodiments. 11...Anode material, 10...Cylinder, 12...End face, 13...Dissimilar metal thin plate for joining, 15... Joint, 16, 17
...Diffusion bonding layer, 19...Notch. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6

Claims (1)

[Claims] 1 A flat plate-shaped anode material made of copper is rolled into a cylinder shape, and then nickel (Ni), silver (Ag), gold (
A metal foil made of one selected from Au), stainless steel, or an alloy mainly composed of these is sandwiched and adhered, and the metal foil and the anode material in the vicinity are locally irradiated with a beam to melt and form an airtight seal. A method for manufacturing a magnetron anode, characterized by: