JPH03283234A - Filter circuit device for magnetron - Google Patents

Abstract

PURPOSE:To stably weld one end portion of each of choke coils to one end portion of each corresponding one of through-conductors in a linearly contacted condition by including a twist portion prepared through the process of twisting each of through-conductors round the axis thereof in a flat region close to the end portion of the through-conductor and then burying a part of this twist portion into a synthetic resin in paired cylindrical dielectric comprising first and second electrodes additionally arranged respectively at the end portions of both openings thereof. CONSTITUTION:Paired through-conductors 16, 17 are each formed out of a ribbonlike metal piece. The outer end portions 16a, 17a and inner end portions 16b, 17b of the through-conductors all are formed in the same flatness. Flat regions close respectively to the inner end portions include their twist portions 16c, 17c each prepared through the process of twisting each of the through- conductors round the axis thereof in a rotative angle of about 90 degrees, and the twist portions 16c, 17c are respectively buried into a synthetic resin 11. Then, one end portion of each of choke coils 12, 13 is welded to each corresponding one of the flat inner end portions 16b, 17b.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a filter circuit device for a magnetron used in microwave heating equipment such as a microwave oven.

BACKGROUND ART In general, the cathode terminal lead-out portion of a magnetron is formed of a stem made of ceramics, so microwaves leaking through the cathode terminal lead-out conductor not only leak to the power supply side but also leak outside the tube through the stem. Therefore, an LC filter circuit device consisting of a choke coil and a capacitor is connected to a cathode terminal within a shield case.

The capacitor of the filter circuit device is a feed-through type,
Usually, it is configured as shown in FIG. A pair of cylindrical dielectrics 3.4 penetrated by a pair of through conductors 1.2 form a capacitor together with electrodes 5.6, 7.8 attached to both open ends of each. The first electrodes 6 and 8 are connected to the through conductor 1°2, and the second electrodes 5 and 7 are connected to the metal substrate 9, respectively. 10 is an insulating cylinder made of synthetic resin; 11 is a block-shaped synthetic resin; 1a;

2a is the flat outer end of both prize conductors 1 and 2, lb;

2b indicates the inner ends of both prize conductors 1 and 2.

Such a feedthrough capacitor is attached to the side wall of a metal shield case (not shown) using a metal substrate 9, and the inner end portions 1b, 2b are connected to choke coils 12, 2b as shown in FIG. 4 within the shield case. 13 are welded to one end of each. Note that the other ends of both choke coils 12 and 13 are connected to the cathode terminal of the magnetron. 14
．． 15 indicates a ferrite core.

Problem to be Solved by the Invention By the way, each inner end 1b, 2b of the through conductor 1.2 is in the form of a round bar, so when welding one end of each choke coil 12.13 to the inner end 1b, 2b, it is necessary to It is rare that there is a line contact, and most of the time it is a point contact. If welding is performed in such a state of point contact, a stable and reliable welding effect cannot be obtained.

Means for Solving the Problems The present invention has been made to solve the conventional problems, and according to the present invention, a pair of cylinders each having a first electrode and a second electrode attached to both open ends thereof are provided. Each of the shaped dielectrics is provided with a through conductor penetrating through itself and connected to the first electrode, and the second electrode is connected to the metal substrate. The present invention includes a feedthrough capacitor formed by integrally solidifying a portion of a dielectric material and a portion of the metal substrate with a synthetic resin, and a pair of choke coils whose ends are welded to one flat end of the feedthrough conductor. and,
A flat region of the through conductor near the one end is provided with a twisted portion twisted about its axis, and at least a portion of this twisted portion is embedded in the synthetic resin.

Function With this configuration, one end of the choke coil is welded to one flat end of the through conductor, so the two are always in line contact and stably welded, achieving a reliable welding effect. . Furthermore, since at least a portion of the twisted portion provided in the flat area near the one end is embedded in the synthetic resin, the contact with the synthetic resin is good, and even though the one end is flat, It can increase its mechanical strength and eliminate the risk of bending or breaking even when strong force is applied during welding.

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

The feedthrough capacitor shown in FIG. 1 differs from the feedthrough capacitor shown in FIG. 3 in that a pair of feedthrough conductors 16.
17 is formed of a ribbon-shaped metal piece, and its outer ends 16a, 17a and inner ends 16b, 17b are both flat, and in the flat area near the inner end, there is an approximately Twisted portion 16c, 1 twisted at a rotation angle of 90 degrees
7c, and the twisted portions 16c and 17c are made of synthetic resin 11.
There is no difference in other configurations. and a flat inner end portion 16b.

One end of each choke coil 12, 13 is welded to 17b in the relationship shown in FIG.

In the above-described embodiment, the twisted portions 16c and 17c are all embedded in the synthetic resin 11, but they may be partially embedded. Further, the midsection of the through conductor 16 and 17, particularly the portion located within the dielectric body, may be shaped into a round bar.

Effects of the Invention Since the present invention is configured as described above, one end of the choke coil can be stably welded to one end of the through conductor in a line contact state, and a reliable welding effect can be obtained.
Although the inner end of the through conductor is flat,
It is possible to improve both its mechanical strength and its contact with synthetic resins.

[Brief explanation of drawings]

FIG. 1 is a side sectional view of a feedthrough capacitor of a filter circuit device embodying the present invention, and FIG. 2 is a perspective view of the main parts of the device.
FIG. 3 is a side sectional view of a conventional feedthrough capacitor, and FIG. 4 is a perspective view of a conventional filter circuit device. 3.4...Dielectric, 5.6,7.8...
- Electrode, 9...Metal substrate, 10...Insulating cylinder, 16.17...Through conductor.

Claims (1)

[Claims] Each of a pair of cylindrical dielectrics having first and second electrodes attached to both open ends thereof is provided with a through conductor penetrating through itself and connected to the first electrode, A through-type capacitor is formed by connecting a second electrode to a metal substrate, and solidifying a midsection of the through conductor, the pair of cylindrical dielectrics, and a part of the metal substrate together with a synthetic resin, and a flattening of the through conductor. a pair of choke coils having one end welded to one end; the through conductor has a twisted portion twisted about its axis in a flat region near the one end; A filter circuit device for a magnetron, characterized in that at least a portion thereof is embedded in the synthetic resin.