JPH0423311Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a high-voltage feedthrough capacitor used as a noise filter in high-frequency, high-power equipment, such as microwave ovens, broadcasting magnetrons, or X-ray tubes. In a feed-through type capacitor in which a feed-through capacitor fixed on one side of a grounding fitting is surrounded by an insulating case, and an insulating resin is filled around the feed-through capacitor surrounded by the insulating case, the insulating case surrounds the terminal part of the feed-through conductor. By expanding the inner diameter of the part, the space distance between the terminal part of the through conductor, which is the high voltage generating part, and the insulating case is increased, and the creepage distance from the terminal part to the grounding fitting is increased. , with increased pressure resistance and improved burnout resistance.

Prior Art Fig. 4 is an exploded perspective view of a conventional feedthrough capacitor, Fig. 5 is a front partial sectional view, and Fig. 6 is a side partial sectional view. , the common electrode 6 of the feedthrough ceramic capacitor 1 having mutually independent electrodes 4 and 5 and the common electrode 6 is fixed onto the floating portion 71 of the grounding fitting 7 by means such as soldering, and the feedthrough ceramic capacitor 1 The through conductors 11 and 12 covered with the insulating tubes 9 and 10 are passed through the through holes 2 and 3 of the grounding fitting 7 and the through hole 8 of the grounding fitting 7.
12 are inserted into electrode connecting bodies 13 and 14 which are soldered and fixed onto the electrodes 4 and 5 of the feedthrough ceramic capacitor 1 by means such as soldering.

The grounding metal fitting 7 is formed by drawing a metal plate such as an iron plate, so that the middle part of one side is
A floating portion 71 rising from the planar outer periphery at an appropriate height is projected, and an insulating case 1 is placed around the outer periphery of the floating portion 71 so as to surround the through-hole ceramic capacitor 1.
7, and a through conductor 11, on the other side.
An insulating cover 18 is inserted so as to surround 12. Then, an externally filled insulating resin 15 made of epoxy resin or the like is filled inside and outside the through-hole ceramic capacitor 1 surrounded by the insulating case 17 and the insulating cover 18.
and an internal filling insulating resin 16 to ensure moisture resistance and insulation.

At the ends of the through conductors 11 and 12 on the insulating case 17 side, there is a terminal part 11 of a Faston tab connector type.
1,121 are formed integrally. Terminal part 11
1,121 is for easy connection of external connector.
It is made to protrude higher than the end of the insulating case 17.

The insulating case 17 is generally formed into a cylindrical shape having approximately the same inner diameter using a thermoplastic insulating resin such as PBT.

FIG. 7 is a front partial sectional view when the above-mentioned feedthrough capacitor is used as a magnetron filter, and FIG. 8 is a plan partial sectional view.
9 is a filter box. The grounding fitting 7 of the feedthrough capacitor A is attached and fixed to the filter box 19. 20, 21 are through conductors 11, 1
2 are respectively connected to the yoke coils, and 22 is the cathode stem of the magnetron.

FIG. 9 is a diagram showing the connection structure of the receptacles 201 and 211 to the feedthrough capacitor A.
211 is fitted. Receptacle 201,
211 is drawn into a transformer section of a microwave oven or the like.

Problems to be solved by the invention As mentioned above, conventionally, the insulating case 17 is
Since it is made of thermoplastic insulating resin such as PBT into a cylindrical shape with approximately the same inner diameter, when used in a microwave oven magnetron, etc., as shown in Figure 9,
When the receptacles 201, 202 connected to the inductors 20, 21 are inserted into the terminal portions 111, 121, the spatial distance _G1 between the outer surfaces of the receptacles 201, 202 and the inner surface of the insulating case 17 becomes narrower.

Furthermore, when the feedthrough capacitor is used in a magnetron of a microwave oven, etc., the environment in which it is used is a place with high humidity and a lot of oil smoke, dirt, dust, etc., such as a kitchen or kitchen. As described above, in addition to the poor usage environment, high voltage is applied and electrostatic force is generated, so oil smoke, dirt, and dust in the atmosphere adhere to the surface of the insulating case 17. When condensation due to changes in ambient temperature is added to this, the surface of the insulating case 17 becomes hygroscopic and its surface resistance decreases significantly.

Therefore, the narrow spatial distance G ₁ between the terminal parts 111, 121 and the insulating case 17 and the insulating case 1
Due to moisture absorption due to oil smoke, dirt, dust, and dew condensation adhering to the surface of 7, it passes through the surface 151 of the externally filled insulating resin 15 and the surface of the insulating case 17 from the terminal portions 111 and 121, and reaches the grounding fitting 7 on the path A.
There was a problem in that creeping discharge occurred and the insulating case 17 was burnt out.

Insulating case 1 is used as a means to prevent burnout accidents.
It is also known that 7 is made of flame-retardant thermosetting resin or porcelain, but in this case, the inner surface of the insulating case 17 is The external filling insulating resin 15 adheres strongly to the external filling insulating resin 1.
5, a tensile stress is generated in the direction of the insulating case 17. Therefore, a problem arises in that peeling occurs at the interface between the externally filled insulating resin 15 and the through-hole ceramic capacitor 1, resulting in a breakdown voltage failure.

Means for Solving the Problems In order to solve the above-mentioned conventional problems, the present invention provides a method in which a grounding metal fitting and one of the electrodes formed on opposing surfaces are brought into contact with one side of the grounding metal fitting. a fixed feedthrough capacitor, an insulating case surrounding the feedthrough capacitor, a feedthrough conductor provided through the feedthrough capacitor and electrically connected to the other electrode of the feedthrough capacitor, and the feedthrough surrounded by the insulating case. In a feed-through capacitor including an insulating resin filled around the capacitor, the insulating case extends an inner diameter portion of a portion surrounding a terminal portion of the feed-through conductor led out on the opposite side from the grounding metal fitting. It is characterized by:

Function The feed-through capacitor according to the present invention has a structure in which the insulating case expands the inner diameter of the portion surrounding the terminal portion of the feed-through conductor, so when used as a filter for a magnetron, etc., the feed-through conductor Even when a receptacle is connected to the terminal part of the insulating case, ensure that there is sufficient space between the receptacle and the inner wall of the insulating case to prevent burnout accidents even if oil smoke, dirt, dust, etc. adhere to the insulating case. can be prevented.

Embodiment FIG. 1 is an exploded perspective view of a feedthrough capacitor according to the present invention, FIG. 2 is a front partial sectional view, and FIG. 3 is a side partial sectional view thereof. In the figures, the same reference numerals as in FIGS. 4 to 6 indicate the same components. The insulating case 17 has a structure in which the inner diameter part of the upper part that surrounds the terminal parts 111 and 121 of the through conductors 11 and 12 is expanded over the entire circumference, and a stepped part 171 is provided. It is desirable that the stepped surface 172 be located at a position that is not lower than the surface 151 of the insulating resin 15.

When the feedthrough capacitor according to the present invention is used as a filter for a magnetron, etc., the capacitor shown in FIGS.
As shown in FIG.
1, even if the receptacle 201,
A sufficient space distance is ensured between 211 and the inner wall surface of the insulating case 17, and even if oil smoke, dirt, dust, etc. adhere to the insulating case 17, a burnout accident can be reliably prevented.

Effects of the invention As described above, according to the invention, when used as a filter for a magnetron, etc., even when a receptacle is connected to the terminal part of a through conductor, there is a gap between the receptacle and the inner wall surface of the insulating case.
It is possible to provide a feed-through capacitor that secures a sufficient spatial distance and can reliably prevent burnout accidents even when oil smoke, dirt, dust, etc. adhere to the insulating case.

[Brief explanation of the drawing]

FIG. 1 is an exploded perspective view of a feedthrough capacitor according to the present invention, FIG. 2 is a front partial sectional view, FIG. 3 is a side partial sectional view, and FIG. 4 is an exploded perspective view of a conventional feedthrough capacitor. , FIG. 5 is a front partial sectional view, FIG. 6 is a side partial sectional view,
Figure 7 is a front partial cross-sectional view when a feedthrough capacitor is used as a magnetron filter, Figure 8
This figure is a partial cross-sectional plan view, and FIG. 9 is a partial cross-sectional view showing how the receptacle is connected to the through conductor. 1... Feedthrough capacitor, 4, 5, 6... Electrode,
7...Grounding metal fitting, 11, 12...Through conductor, 15
...Insulating resin, 17...Insulating case, 171...
Step section, 172... step surface.

Claims (1)

[Scope of utility model registration request] a grounding fitting, a feedthrough capacitor in which one of electrodes formed on opposing surfaces is fixed on one side of the grounding fitting; an insulating case surrounding the feedthrough capacitor; and a feedthrough capacitor provided passing through the feedthrough capacitor. In a feed-through capacitor comprising a feed-through conductor electrically connected to the other electrode of the capacitor, and an insulating resin filled around the feed-through capacitor surrounded by the insulating case, the insulating case is different from the grounding fitting. A feed-through capacitor characterized in that an inner diameter portion of a portion surrounding a terminal portion of the feed-through conductor led out to the opposite side is widened.