JPS61193327A - Manufacture of magnetron for microwave oven - Google Patents

Abstract

PURPOSE:To obtain a magnetron easy to be regulated in its frequency by deeply contracting a thin plate into a U-shape while cutting the bottom for forming a pair of strap rings to be connected to a vane. CONSTITUTION:A copper plate 34 having thickness 0.5-1mm is deeply contracted to make rings while the bottom 35a and the end surfaces 35b, 35c are cut for forming a pair of strap rings 32 and 33. The end surface 35a is connected only to one side of a vane 2 in the tube axis direction. According to said constitution, a soldering yield to the vane 2 gets extremely good and when the strap rings 32 and 33 are transformed in the radial direction, resonance frequency can easily be regulated. Further, the strap rings ease up thermal stress between the strap rings and the vane. Still more the height (h) can be easily formed. However, when the interval W is too much reduced, undesirable solder cross-over is liable to occur.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a method of manufacturing a magnetron for a microwave oven, and particularly to an improvement of a strap ring thereof.

[Background technology and its problems]

The conventionally used microwave oven magnetron is
It is constructed as shown in Fig. 4 and Fig. 5, and Fig. 5 shows the
This is an enlarged view of the main part of the figure. That is, on the inner surface of the copper anode cylinder 1, a plurality of copper vanes 2 are arranged radially toward the center. This vane 2 has a pair of strap rings 30 and 31 on both sides in the tube axis direction.
are joined every other time. In this case, the anode cylinder 1,
The vane 2 and the strap ring 30.31 are joined to each other by a silver-copper alloy. At the center of the anode cylinder 1 is a spirally carbonized thorium tungsten steel.
A cathode 3 made of a filament is provided, and both ends of the cathode 3 are fixed to an end hat 9 and an end hat 1 through an opening 10, respectively. The end chip f10 and the end hat 9 are attached to the rod-shaped cathode support 4, and the end hat 11 is attached to the rod-shaped cathode support 5. These cathode supports 4 and 5 are made of a high melting point metal such as molybdenum. Furthermore, iron ball beads 19 and 13 are fixed to both ends of the anode cylinder 10, respectively. An output part 40 is provided protrudingly from one pole piece 19, and this output part 40 consists of a cylindrical sealed metal body 14, a ceramic cylinder 16, a sealed metal body 20, an exhaust pipe 21, and an end cap 1.
7, an antenna feeder 18, which is connected to one of the vanes 2. Further, an input section 50 is provided on the other pole piece 13 in a protruding manner. That is, the ceramic stem 8 is protruded through a metal sealing body 15 made of a thin iron plate with a thickness of 0.4 m+. Cathode supports 4 and 5 are supported through the ceramic stem 8 and connected to input terminals 6 and 7 attached to the tip of the ceramic stem 8.

By the way, the strap ring 30.31 has conventionally been manufactured by punching out a copper plate with a thickness of about 1.5 mm using a press, but such a strap ring 30.31 has resonance as shown in Fig. In order to handle a considerable amount of the capacitive component of the container, the height h is made thicker, and the distance W between both Strazzoli rings 30 and 31 is made smaller, so that the strap ring 3 is proportional to h/w.
Capacity must be secured for 0.31 hours.

However, configuring the magnetron in this way has the following disadvantages.

That is, first of all, since the height h is a dog, the strap ring 3
Manufacturing by 0.31 punching is not so easy. or,
A rough fracture surface S is generated, and the yield of brazing at this portion is reduced. Furthermore, since the strap rings 30 and 31 require a certain width in the radial direction, they are difficult to deform mechanically, and deformation of the strap rings for frequency adjustment is not easy.

These tendencies become more pronounced in a type in which the strap ring 30° 31 is located only on one side of the vane 2 in the tube axis direction. This is because the capacity to be handled between the strap rings 30 and 31 is doubled per pair.

[Purpose of the invention]

An object of the present invention is to provide a method for manufacturing a magnetron for a microwave oven that allows easy frequency adjustment and prevents strap rings from breaking.

[Summary of the invention]

This invention relates to the manufacture of a magnetron for a microwave oven, which is characterized in that a thin plate is deep drawn into a U-shaped half cross section, the bottom part of the plate is cut to form a pair of strap rings, and each strap ring is joined to a vane. It's a method.

Embodiments of the Invention A method for manufacturing a magnetron for a microwave oven according to the invention is constructed as shown in FIGS. 1 to 3, and FIG. This is a microwave magnetron. Further, FIG. 2 is an enlarged cross-sectional view showing the main part of FIG. 1, and FIG. 3 is a process explanatory diagram showing a method for manufacturing the straggling. In addition, the same parts as the conventional example are as follows.
The same reference numerals are used to omit detailed explanation.

Now, in the embodiment of the present invention, as is clear from FIG. 1, six of the pair of strug rings 32 and 33 are joined to one side of the vane 2 in the tube axis direction. And, this strap ring 32°33 is
First, as shown in (,), a thin copper plate 34 with a thickness of 0.5 to 1°0 days is deep drawn, and then
An annular body 35 having a U-shaped half cross section as shown in b) is formed. Next, the bottom 35a and the end surface 3 of this half-section U-shaped body 35 are
5b, cut 35cf. As a result, a pair of strap rings 32 and 33 as shown in FIG. 3(C) are obtained. This strap ring, 32° 33'f, is joined only to one side of the vane 2 in the tube axis direction, as described above. In this case, each strap ring 32, 33 is joined to the vane 2 at its bottom end 35a, as is clear from FIG.

Note that deep drawing may be performed using hydraulic pressure.

〔Effect of the invention〕

According to this invention, the thin plate 34 is deep drawn to form the half-section U-shaped body 35, and the bottom 35m and end faces 35b, 35
c is cut to form a pair of strap rings 32, 33, and each strap ring 32, 33 is joined to one side of the vane 2 in the tube axis direction. Brazing has an extremely high yield, and by deforming the strap rings 32 and 33 in the radial direction, the resonance frequency can be easily adjusted. Furthermore, thermal strain stress generated between the strap rings 32, 33 and the vane 2 is also alleviated by the cushioning properties of the strap rings 32, 33, and the heat resistance of this portion is also improved. Further, it is possible to manufacture the height h to be large without overdoing it. Incidentally, it is not desirable to make the interval W too small in order to increase h'/W' because soldering occurs between the strap rings 32 and 33.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing a microwave oven magnetron manufactured by the manufacturing method of the present invention, FIG. 2 is a cross-sectional view showing an enlarged main part of FIG. 1, and FIGS. b), (b)
4 is a cross-sectional view showing a microwave oven magnetron manufactured by the conventional manufacturing method, and FIG.
FIG. 3 is a cross-sectional view showing an enlarged main part of the figure. 1...Anode cylinder, 2...Vane, 32.33...
Strap ring, 34... Thin plate, 35... Half-section U-shaped body, 35a... Bottom, 35b, 35c... End surface.

Claims (1)

[Claims] A method for manufacturing a magnetron for a microwave oven in which a plurality of vanes are arranged radially inside an anode cylinder and a strap ring is joined to the vanes, comprising: deep drawing a thin plate into a U-shaped half cross section; A method of manufacturing a magnetron for a microwave oven, comprising: cutting the bottom of the magnetron to form a pair of strap rings, and joining each strap ring to the vane.