JPH0258733B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a noise preventer used in high frequency generators such as high frequency oscillators and induction coils.

Such a noise preventer is used, for example, in a magnetron as shown in FIG. In the magnetron, an output part 3 is connected to one end of an anode cylinder 1 containing a cavity resonator through a cup-shaped seal part 2 to form an antenna, and an output part 3 is connected to the other end of the anode cylinder 1 through a cup-shaped seal part 4. An insulator 5 is sealed to form a stem. The above is the general configuration of a vacuum vessel that serves as a microwave oscillation source. After the vacuum vessel is completed, a plurality of annular heat radiation fins 6 are fixed to the outer periphery of the anode cylinder 1 by means such as welding or press-fitting.
Furthermore, permanent magnets 7 and 8 are installed at both ends of the anode cylinder 1, respectively.
The vacuum container and the permanent magnets 7 and 8 are clamped and fixed by the elasticity of the yoke 9. Further, a gasket 10 made of a thin metal wire is press-fitted between the cup-shaped seal component 2 and the yoke 9. Further, a shield case 11 is forcibly fitted to the cup-shaped seal component 4, and within this shield case 11, one end of the chi-yoke coil 12 is connected to a cathode terminal 13 led out from inside the vacuum container through an insulator 5, and further, the chi-yoke coil 12 The other end is led to a power source outside the shield case 11 via a feedthrough capacitor 14. Here, the chiyoke coil 12 and the feedthrough capacitor 14 form an LC filter circuit. FIG. 2 schematically shows the structure of a noise preventer that prevents the noise generated from the high frequency generator of the magnetron from leaking to the outside.

Usually, a copper wire is used for the chiyoke coil 12, and the feedthrough capacitor 14 has a center conductor 15, a center conductor 15 and a dielectric 1, as shown in FIG.
6 and the electrode fitting 17 that electrically connects the dielectric 1
6 and a resin cover 19. Conventionally, in order to connect the center conductor 15 to the chiyoke coil 12,
Caulking, soldering, screwing, etc. have been adopted, but these conventional connection structures have the following drawbacks.

First, in the case of the caulking method, it is possible to make the center conductor 15 into a cylindrical shape as shown in FIG. This has disadvantages in that it is necessary to use a different material, and it is also necessary to restrict the diameter of the conductive wire of the tie yoke coil 12 in order to perform proper caulking.

In addition, in the case of a soldered structure, operations such as preliminary soldering, application of flux, and removal of flux after soldering are required to obtain a good joint condition, which requires a large amount of work time, and it is difficult to remove the flux. This has the disadvantage that residual flux tends to cause corrosion of metal materials, reducing the reliability of equipment.

Next, in the case of a screw-fastened structure, the chiyoke coil 1
2 and the center conductor 15 need to be shaped with holes suitable for screwing, and additional parts such as screws and nuts are required, which is disadvantageous in terms of cost. As described above, all conventional connection structures have serious drawbacks in terms of cost or reliability.

The present invention has been made in view of the above-mentioned drawbacks of the prior art, and it is an object of the present invention to provide a noise preventer having a simple structure, low cost, and high reliability.

Hereinafter, the present invention will be explained with reference to illustrated embodiments.

FIG. 4 shows one embodiment of the invention. The chiyoke coiled copper wire 21 is bent and shaped, and the end portion 22
are oriented in the same direction as the end 32 of the center conductor 31 of the feedthrough capacitor 30 and contact each other in parallel, and the termination surface 25 of the chiyoke coil conductor 21 and the termination surface 33 of the center conductor 31 of the feedthrough capacitor 30 are close to each other. However, the welding portion 23 is welded by arc welding.

Normally, the amount of penetration in arc welding varies greatly depending on the welding current, welding time, etc.
When welding the York coil conducting wire 21 and the center conductor 31 of the feedthrough capacitor with their end surfaces abutting each other or crossing their ends, there is a drawback that melting due to excessive penetration or poor penetration is likely to occur. By providing a parallel contact portion of a certain length as shown in the figure, the amount of penetration can be allowed within a certain range, making the work extremely stable. In particular, it is difficult to control the amount of penetration of copper, which is often used as a conductor in noise prevention circuits, during welding.
The above connection structure is extremely effective. Also, since both conductors are welded together, electrical contact is perfect.
Experiments have confirmed that no special pretreatment or flux application is required.

On the other hand, if the center conductor of the feed-through capacitor is made of a material such as iron, which has a higher melting point than copper, the end surface 25 of the chiyoke coil copper wire 21 as shown in FIG.
is slightly set back from the end surface of the center conductor 31 of the feed-through capacitor, and the end portion 22 is made of a copper wire with a low melting point.
By melting the copper, it is possible to weld the copper to the iron at the welded portion 23 and obtain a good connection.

Furthermore, as shown in FIG. 6, the end portion 24 of the York coil conducting wire 21 is wound around the center conductor 31 of the feedthrough capacitor 30, and the terminal end surface 25 after this winding is welded by arc welding to form a welded portion 23. You may also do so. This structure has the advantage of not only reinforcing the mechanical strength of both ends but also facilitating positioning before assembly.

As is clear from the above description, the noise suppressor according to the present invention has the following remarkable effects. (1) It is not necessary for the cross-sectional shape of the choke coil conductor and the center conductor of the feedthrough capacitor to be particularly cylindrical, and a simple wire-shaped material can be used. (2) No auxiliary parts such as screws or nuts are required. (3) No special pretreatment or flux is required. (4) A good electrical connection can be obtained. (Five)
There is no reduction in reliability due to corrosion or loosening. These features make it possible to easily obtain a low-cost and highly reliable noise suppressor.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view of the magnetron, Figure 2 is an explanatory diagram conceptually showing the structure of a noise preventer, and Figure 3 is a cross-section of the main part showing the connection structure between the choke coil and feedthrough capacitor of a conventional noise preventer. An explanatory diagram, FIG. 4 is a cross-sectional explanatory diagram of a main part showing one embodiment of a connection structure between a chioke coil and a feedthrough capacitor of a noise suppressor according to the present invention, and FIG. 5 is a main part explanation showing another embodiment. FIG. 6 is an explanatory cross-sectional view of a main part showing still another embodiment. 20... Chiyoke coil, 22... End, 23... Welded part, 24... End, 30... Feedthrough capacitor, 3
1...Center conductor.

Claims (1)

[Claims] 1. In a magnetron having a noise suppressor formed by directly connecting the center conductor of a feedthrough capacitor and a chiyoke coil conductor, the end of the chiyoke coil conductor and the end of the center conductor of the feedthrough capacitor are the ends of the center conductor. The chiyoke coil conducting wire is bent toward the chiyoke coil main body side without bending and deforming the chiyoke coil conductor, and the end surfaces of the respective ends are brought into contact with each other in the same direction so as to be close to each other, and the ends of the chiyoke coil conducting wire are 1. A magnetron having a noise preventer, characterized in that a terminal surface of the part is welded to an end or a terminal surface of the center conductor of the feedthrough capacitor.