JPS638048Y2 - - Google Patents

Description

[Detailed explanation of the idea] [Technical field of invention] This idea concerns improvements to magnetrons.

[Technical background of the invention]

Conventionally, the main parts of a magnetron are constructed as shown in FIG. 1, and a plurality of strip-shaped vanes 2 are arranged and fixed inside an anode cylinder 1. Furthermore, substantially funnel-shaped pole pieces 3 are provided at both ends of the anode cylinder 1.
is fixed to one pole piece 3, and an output part 10 consisting of a metal sealing body 4, a ceramic cylinder body 5, a metal ring 6, an exhaust pipe 7, an output cap 8, an antenna conductor 9, etc. is protrudingly provided. There is. Note that a cathode stem is provided protruding from the other pole piece (neither is shown). The antenna conductor 9 has one end with a rectangular cross section and is connected to one vane 2a, and the other end is a round bar and is located inside the exhaust pipe 7 and is clamped by the exhaust pipe 7.
In addition, the vane connection part of the antenna conductor 9 is eccentric from the tube axis by L in order to obtain the desired high frequency output and stable operation, and on the other hand, since the output part 10 is provided protruding in the tube axis direction, has at least two bending parts A and B.

In such a magnetron, during operation, microwave energy generated at the anode passes through the antenna conductor 9 and is propagated to the outside from the ceramic cylinder 5 and the output cap 8. Note that the metal ring 6 and the exhaust pipe 7 are formed in a chiyoke structure that suppresses harmonic components of microwave energy.

[Problems with background technology]

The antenna conductor 9 generates heat due to the high-frequency current flowing therethrough, and standing waves are generated in the output section 10 due to the external load conditions of the magnetron, so that local heat is generated in the upper part of the antenna conductor 9 or in the chain structure. For this reason, the antenna conductor 9 itself may reach a fairly high temperature. Therefore, the expansion of the antenna conductor (generally made of Cu with a high expansion coefficient) is large relative to the envelope of the output section 10, and the upper part of the antenna conductor 9 repeatedly expands and contracts in the direction of arrow C due to the on/off operation of the magnetron. It turns out. Therefore, the force indicated by the arrow d is applied to the inclined portion of the antenna conductor 9, and there is a possibility that the bent portions A and B may break due to thermal fatigue.

[Purpose of invention]

The purpose of this invention is to provide a magnetron that prevents the antenna conductor from breaking due to on/off operations.

[Summary of the idea]

This idea is based on a magnetron in which a plurality of vanes are arranged and fixed radially inside an anode cylinder, and an antenna conductor is connected to one of the vanes. , and one end is connected to one of the vanes at a predetermined angle with respect to the tube axis.

[Example of idea]

The magnetron of this invention is constructed as shown in FIGS. 2 and 3, and the same parts as in the conventional example (FIG. 1) are given the same reference numerals. In this idea,
In order to eliminate the above-mentioned conventional drawbacks, the antenna conductor and its vane connection are improved. That is, the antenna conductor 11 is made of oxygen-free copper with a rectangular cross section, and one end is inclined at a predetermined angle θ with respect to the tube axis direction and is electrically connected to the vane 2b (details will be described later).
The other end is clamped to the exhaust pipe 7 by pressure. Further, although the antenna conductor 11 is partially straight in the upper part, the antenna conductor 11 is bent into a gentle arch shape as a whole, and there is no significant bending part as in the conventional antenna conductor. The antenna conductor 11 and one vane 2b are connected by a loose mechanical connection, such as by providing slits 12 and 13 and fitting the slits 12 and 13 into each, as shown in FIG. 3, for example. . Note that it is preferable not to use silver brazing for connections. In this case, the bottom 12 of each groove 12, 13
A slight gap is provided between a and 13a. The antenna conductor 11 passes through the hole of the pole piece 3 without contacting it.

In addition, since the configuration other than the above is the same as that of the conventional example, the same parts are given the same reference numerals and detailed explanations will be omitted.

[Effect of idea]

According to this invention, since the antenna conductor 11 has a gentle arc shape as a whole and has no bent portion, there is almost no concentration of thermal stress due to expansion and contraction, and no breakage occurs. Furthermore, since one end of the antenna conductor 11 is not mechanically strongly fixed, the antenna conductor 1
The vane end of No. 1 is deformed in the direction of arrow g, and the deformation in the direction of d' is very small. Therefore, the stress concentration applied to the antenna conductor 11 is further reduced, and since the dimension of the gap between the pole piece 3 and the through hole does not change, there is no possibility that the degree of coupling will change and cause instability.

Note that the same effect can be obtained even when the antenna conductor 11 has a circular cross section.

In addition, in the above embodiment, as shown in FIG. 3, slits 1 are provided in both the antenna conductor 11 and the vane 2b.
2 and 13, but the antenna conductor 11 with the slit 12 and the vane 2 without the slit 13
In the case of combination b, the antenna conductor 11 does not have a slit 12 and the vane 2b has a slit 13.
Connection is also possible in the case of a combination of the following, and the same effect as in the above embodiment is obtained.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing a conventional magnetron, Fig. 2 is a sectional view showing a magnetron according to an embodiment of the invention, and Fig. 3 is an exploded perspective view showing the main parts of Fig. 2 on an enlarged scale. . 1... Anode cylinder, 2... Vane, 11... Antenna conductor, 12, 13... Slit.

Claims (1)

[Claims for Utility Model Registration] (1) A magnetron in which a plurality of vanes are arranged and fixed radially inside an anode cylinder, and an antenna conductor is connected to one of the vanes, in which the antenna conductor is loosely connected throughout. 1. A magnetron characterized in that the magnetron has an arcuate shape, and one end thereof is connected to one of the vanes at a predetermined angle with respect to the tube axis. (2) The magnetron according to claim 1, wherein a slit is provided in at least one of the antenna conductor and the vane, and the two are connected by fitting and caulking the slit.