JP2007019352A - High-voltage feed-through capacitor and magnetron - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high-voltage feed-through capacitor capable of filling an insulation filler in one process and ensuring high sealing function and withstand voltage function, and to provide a magnetron. <P>SOLUTION: A insulation cover 6 has a partitioning portion 63 on its one end, and the one end side having the partitioning portion 63 is closely fitted to the internal surface of a concave portion 30 of a grounding metal fixture 3. Through conductors 21, 22 are connected to divided electrodes 12, 13 of a capacitor 1, and guided while penetrating the capacitor 1, the grounding fixture 3 and the partitioning portion 63. The insulation filler 41 is filled in the inside and outside of the capacitor 1. Insulation tubes 71, 72 cover the through conductors 21, 22 in the capacitor 1 side rather than the partitioning portion 63 and their ends abut on the penetration portions of the through conductors 21, 22 in the partitioning portion 63 to constitute a leakage stopper. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a high-voltage feedthrough capacitor and a magnetron using the high-voltage feedthrough capacitor.

  This type of high-voltage feedthrough capacitor is incorporated in a magnetron as a filter that removes unnecessary radiation generated during the oscillation operation of the magnetron, for example, and a general structure is disclosed in, for example, Patent Document 1 ing.

  In this type of high voltage feedthrough capacitor, a high voltage is applied between the grounding metal fitting and the through conductor (center conductor), so that a sufficient withstand voltage must be ensured between the two. Conventionally, as shown in Patent Document 1, etc., as a means for this, an insulating filler made of insulating resin or the like is filled in a large volume from the inside of the capacitor through hole to the inside of the raised portion of the grounding metal fitting. It was.

  For this reason, the amount of the insulating filler used is inevitably increased, and it is easily affected by the thermal expansion / contraction of the insulating filler, resulting in the generation of stress due to the expansion / contraction of the insulating filler and the accompanying decrease in the withstand voltage. I was invited. In addition, the high cost due to an increase in the amount of insulating filler used cannot be ignored.

  Furthermore, since the capacitor is mounted on one surface of the grounding metal, the capacitor is divided into two parts, with the grounding metal as a boundary, on the side where the capacitor is mounted, and on the opposite side. After filling the outer side of the enclosed capacitor with the insulating filler, it is necessary to reverse this and fill the other side with the insulating filler, which limits the ease of manufacturing and cost reduction by reducing the number of processes. was there.

Attempts have been made to fill the insulating filler in one step, but it was difficult to prevent leakage at the lead-out portion of the through conductor, and it was difficult to ensure complete sealing and breakdown voltage.
JP-A-8-78154

  An object of the present invention is to provide a high-voltage feedthrough capacitor and a magnetron that can be filled with an insulating filler in one step and that can ensure a high sealing function and a high withstand voltage function.

  In order to solve the above-described problem, a high-voltage through-type capacitor according to the present invention includes a grounding fitting, a capacitor, an insulating cover, a through conductor, an insulating filler, and an insulating tube. The grounding metal has a raised portion on one side, and the raised portion has a recess on the other side. The capacitor has two through holes, has two divided electrodes on one surface side where the through holes are opened, has a common electrode on the other surface side, and is mounted on one surface of the raised portion, A common electrode is connected to the one surface of the raised portion. The insulating cover is closely fitted to the inner surface of the recess of the grounding metal fitting. There are two through conductors, each of which is connected to the divided electrode and led through the capacitor and the grounding fitting. The insulating filler is filled inside and outside the capacitor. The number of the insulating tubes is two, and each covers the through conductor. The insulating cover is closely fitted to the inner surface of the recess of the grounding metal fitting. The insulating filler is filled inside and outside the capacitor.

  The configuration described above is the basic structure of this type of high-voltage feedthrough capacitor. The feature of the present invention resides in that, in the above-described structure, the structure of the insulating cover fitted in the concave portion of the grounding metal fitting and the usage form of the insulating tube corresponding thereto are devised to achieve the object. That is, in the present invention, the insulating cover has a partition portion on one end side, and one end side with the partition portion is closely fitted to the inner surface of the concave portion of the grounding metal fitting. The insulating tube covers the through conductor on the capacitor side of the partition portion, and an end portion is abutted against a through portion of the through conductor in the partition portion to constitute a leak stopper.

  As described above, the insulating cover has a partition portion on one end side, and one end side with the partition portion is closely fitted to the inner surface of the recess of the grounding metal fitting. It is possible to function as an insulating filler leakage stopper for the entire recess. For this reason, it is possible to fill the insulating filler from the side of the capacitor opposite to the insulating cover, that is, from one side with the ground metal fitting as a boundary.

  In order to be able to fill the insulating filler on one side, a filling path connected to the through hole from the outside of the capacitor is necessary. This can be easily realized based on the conventional structure. That is, this type of high-voltage feedthrough capacitor usually includes an electrode connector for connecting the feedthrough conductor to the divided electrode of the capacitor. The electrode connector is usually connected to each of the divided electrodes across the through hole of the capacitor. Therefore, a through hole is provided in the electrode connection body, and the through hole is communicated with the through hole. With the above structure, the inside and outside of the capacitor are connected through the through hole of the electrode connector and the through hole of the capacitor, and a filling path from the outside to the inside of the capacitor is secured, so that one-side filling is possible.

  Next, even if the partition part of the insulating cover is made to function as a filler leakage preventive for the entire recess of the grounding fitting, since the two through conductors penetrate the partition part, the insulation filler leakage preventive from the through part The problem is how to solve the problem. As a means for solving this problem, an insulating tube is used in the present invention. That is, the insulating tube covers the through conductor on the capacitor side with respect to the partition portion, and an end portion is abutted against the through portion of the through conductor in the partition portion to constitute a leakage stopper. Insulating tubes are usually made of a resilient insulating material such as PET, PBT, or silicone rubber. Therefore, using the elasticity, the end of the insulating tube is used as a penetrating portion of the penetrating conductor in the partitioning portion. Strike. As a result, an almost complete leak-proof structure is realized.

  As a specific structure for preventing leakage using the elasticity of the insulating tube, a structure in which the insulating tube is pressed between the electrode connector and the partition portion is effective. Specifically, the partition portion has a structure having a cylindrical portion in a portion through which the through conductor passes, and the insulating tube has a structure pressed between the electrode connector and the bottom portion of the cylindrical portion. According to this structure, a more complete leak-proof structure is realized.

  Since the magnetron according to the present invention uses the above-described high-voltage feedthrough capacitor as a filter, the advantages of the high-voltage feedthrough capacitor according to the present invention are exhibited as they are.

  As described above, according to the present invention, it is possible to provide a high-voltage feedthrough capacitor and a magnetron that can be filled with an insulating filler in a single process and that can ensure a high sealing function and a withstand voltage function.

  Other features of the present invention and the operational effects thereof will be described in more detail by way of examples with reference to the accompanying drawings.

  1 is a plan view showing an embodiment of a high-voltage feedthrough capacitor according to the present invention, FIG. 2 is a sectional view taken along line 2-2 of FIG. 1, and FIG. 3 is a sectional view taken along line 3-3 of FIG. The illustrated high voltage feedthrough capacitor includes a capacitor 1, through conductors 21 and 22, a grounding fitting 3, an insulating filler 41, a second insulating filler 42, an insulating case 5, and an insulating cover 6. Insulating tubes 71 and 72.

The capacitor 1 includes a dielectric ceramic body 11, divided electrodes 12 and 13, and a common electrode 14. Two through holes 15 and 16 are provided in the dielectric ceramic body 11. The composition of the dielectric ceramic body 11 is arbitrary. For example, it is possible to a main component BaTiO ₃ -BaZrO ₃ -CaTiO _3, a composition comprising one or more additives. It is preferable that the dielectric ceramic body 11 has an appropriate R (roundness) as a whole in order to avoid concentration of mechanical and electrical stress.

  The two divided electrodes 12 and 13 are provided on one surface side of the dielectric ceramic body 11 so as to surround a region where the through holes 15 and 16 are opened. Each of the divided electrodes 12 and 13 is spaced apart by a recess 17. Although not shown, a convex portion may be used instead of the concave portion 17. Since the concave portion 17 is for increasing the creepage distance between the divided electrodes 12 and 13, the width and depth thereof are selected so that a necessary creepage distance can be secured. The common electrode 14 is provided on the other surface side of the dielectric ceramic body 11.

  The grounding metal 3 is made of, for example, a conductive metal material such as iron, copper, or brass, and has a raised portion 32 that rises on one surface side of the base portion 31. The floating portion 32 has a through hole 33 that penetrates from one surface side to the other surface side. The above-described capacitor 1 is mounted on the raised portion 32 of the ground metal fitting 3. The capacitor 1 is electrically connected to the surface of the raised portion 32 on the surface of the raised portion 32 by, for example, soldering. It is fixed mechanically. The grounding metal 3 has a recess 30 on the side opposite to the surface on which the capacitor 1 is mounted. The inner surface of the recess 30 of the grounding metal 3 is a stepped surface in which the first rising part 34, the first flange 35, the second rising part 36, and the second flange 37 of the grounding metal 3 are sequentially formed. The through hole 33 is formed inside the second flange 37.

  The through conductors 21 and 22 are two, and are made of a conductive metal material such as iron, copper, or brass, for example. The through conductors 21 and 22 pass through the through holes 15 and 16 of the capacitor 1 and further pass through the through hole 33 of the ground metal fitting 3. The through conductors 21 and 22 are electrically and mechanically connected to the divided electrodes 12 and 13 by electrode connecting bodies 23 and 24. The connection between the electrode connecting bodies 23 and 24 and the divided electrodes 12 and 13 is performed by means such as soldering. Of the through conductors 21 and 22, portions passing through the through holes 15 and 16 of the capacitor 1 are covered with insulating tubes 71 and 72. The insulating tubes 71 and 72 can be made of, for example, PET, PBT, silicone resin, or the like.

  The insulating case 5 is provided on one surface side of the grounding metal 3, and one end is inserted into the outer peripheral side of the floating portion 32. The insulating cover 6 is provided on the other surface side of the ground metal fitting 3, and one end thereof is inserted into the inside of the concave portion 30 generated inside the raised portion 32. The insulating case 5 and the insulating cover 6 can be made of, for example, polybutylene terephthalate (PBT), polyethylene terephthalate (PET), modified melamine, or the like.

  The insulating filler 41 is filled around the capacitor 1 surrounded by the insulating case 5 and inside the through holes 15 and 16 of the capacitor 1. As the insulating filler 41, for example, a thermosetting resin such as a urethane resin or an epoxy resin, a phenol resin, a silicone resin, or the like can be used.

  The configuration described above is of this type except that the insulating filler 41 is continuously filled in the periphery of the capacitor 1 surrounded by the insulating case 5 and in the through holes 15 and 16 of the capacitor 1. This is a basic structure adopted in the high-voltage feedthrough capacitor. The feature of the present invention is that, in the above-described structure, the structure of the insulating cover 6 fitted in the recess 30 of the ground metal fitting 3 and the usage form of the insulating tubes 71 and 72 corresponding thereto are devised. This point will be described in detail with reference to FIG. FIG. 4 is a partially enlarged sectional view of the high-voltage feedthrough capacitor shown in FIGS.

  Referring to FIG. 4, the insulating cover 6 as a whole has a cylindrical shape, and has a partition portion 63 on one end side, and one end side with the partition portion 63 is a portion of the fitting portion 61, and a grounding metal fitting 3 is closely fitted to the inner surface of the recess 30. The insulating tubes 71 and 72 cover the through conductors 21 and 22 on the capacitor 1 side with respect to the partition part 63, and end portions thereof are in close contact with the through parts of the through conductors 21 and 22 in the partition part 63, Constitutes a leak-proof.

  As described above, the insulating cover 6 has the partition portion 63 on one end side, and the fitting portion 61 around the partition portion 63 is closely fitted to the inner surface of the concave portion 30 of the ground metal fitting 3. The partition portion 63 of the insulating cover 6 can function as an insulating filler leakage stopper for the entire concave portion 30 of the ground metal fitting 3. For this reason, it is possible to fill the insulating filler 41 from the side of the capacitor 1 opposite to the insulating cover 6, that is, from one side with the grounding fitting 3 as a boundary.

  In order to be able to fill the insulating filler 41 on one side, a filling path connected to the through holes 15 and 16 from the outside of the capacitor 1 is necessary, but this can be easily realized. That is, this type of high-voltage feedthrough capacitor 1 normally includes electrode connectors 23 and 24 for connecting the through conductors 21 and 22 to the divided electrodes 12 and 13 of the capacitor 1. The electrode connectors 23 and 24 usually straddle the through holes 15 and 16 of the capacitor 1 and are connected to the divided electrodes 12 and 13, respectively. Therefore, through holes 25 are provided in the electrode connecting bodies 23 and 24, and the through holes 25 are communicated with the through holes 15 and 16. With the above structure, the inside and outside of the capacitor 1 are connected through the through holes 25 of the electrode connecting bodies 23 and 24 and the through holes 15 and 16 of the capacitor 1, and a filling path from the outside to the inside of the capacitor 1 is secured. Filling becomes possible.

  Next, even if the partition portion 63 of the insulating cover 6 is made to function as a filler leakage stopper for the entire concave portion 30 of the ground metal fitting 3, the two through conductors 21 and 22 penetrate the partition portion 63. The problem is how to prevent the insulating filler 41 from leaking from the penetrating portion. In order to solve this problem, in the present invention, the insulating tubes 71 and 72 are used. That is, the insulating tubes 71 and 72 cover the through conductors 21 and 22 on the capacitor 1 side with respect to the partition portion 63, and the end portions are abutted against the through portions of the through conductors 21 and 22 in the partition portion 63 to prevent leakage. Configure. Since the insulating tubes 71 and 72 are usually made of an elastic insulating material such as PET, PBT, or silicone resin, the end portions of the insulating tubes 71 and 72 are separated from the partition 63 by using the elasticity. In contact with the penetrating portions of the through conductors 21 and 22. As a result, an almost complete leak-proof structure is realized.

  As a specific structure for preventing leakage using the elasticity of the insulating tubes 71 and 72, in this embodiment, the partition portion 63 has a structure having a cylindrical portion 62 in a portion through which the through conductors 21 and 22 are passed. 71 and 72 are configured to be pressed between the electrode connectors 23 and 24 and the bottom of the cylindrical portion 62. According to this structure, since the insulating tubes 71 and 72 are in close contact with not only the bottom but also the inner surface of the electrode connecting bodies 23 and 24 and the cylindrical portion 62, a more complete leak-tight structure Is realized.

  Next, the one-side casting process of the insulating filler 41 will be described. FIG. 5 is a diagram showing a one-side casting process. In the figure, parts corresponding to the constituent parts appearing in FIG. 4 are given the same reference numerals. Referring to FIG. 5, the periphery of the capacitor 1 surrounded by the insulating case 5 and the insides of the through holes 15 and 16 are in a space state without an insulating filler. In this state, when the fluid insulating filling material is poured from the side of the insulating case 5 as indicated by the arrow A, the fluid insulating filling material is filled around the capacitor 1 surrounded by the insulating case 5. The through holes 25 provided in the electrode connecting bodies 23 and 24 flow in as indicated by an arrow A, and are filled in the through holes 15 and 16.

  In this case, if there is no sealing means on the grounding metal 3 side, the fluid insulating filling material filled in the through holes 15 and 16 will spill from the grounding metal 3 side. In this invention, it has the partition part 63 as this dripping prevention means. In this embodiment, the partition part 63 has a structure having a cylindrical part 62 at a portion through which the through conductors 21 and 22 pass, and the insulating tubes 71 and 72 include the electrode connecting bodies 23 and 24 and the cylindrical part 62. Therefore, a more complete leak-tight structure is realized.

  In the case of the embodiment, since the fitting portion 61 of the insulating cover 6 also has a stepped shape that follows the stepped shape of the inner surface of the recess 30 of the grounding metal 3, the inner peripheral surface of the grounding metal 3 and the insulating cover The leakage of the insulating filler 41 from the outer peripheral fitting surface 6 is completely prevented. This will be supplementarily described with reference to FIG. 5. The stepped portion 61 of the insulating cover 6 includes the first rising portion 34, the first flange 35, the second rising portion 36, and the second rising portion 36 of the grounding fitting 3. The outer shape is such that the inner surface of the second flange portion 37 is in close contact with the inner surface of the second flange portion 37 sequentially. For this reason, the leakage of the insulating filler 41 from the inner peripheral surface of the grounding metal 3 and the outer peripheral fitting surface of the insulating cover 6 is completely prevented.

  Next, another embodiment of the present invention will be described with reference to FIGS. First, in the embodiment of FIG. 6, the stepped portion 61 of the insulating cover 6 is in surface contact with the inner surfaces of the second rising portion 36 and the second flange portion 37 of the grounding metal 3, but the first rising portion 34. And away from the inner surface of the first flange 35. Even with such a structure, the same effects as those of the embodiment shown in FIGS.

  Further, in the embodiment shown in FIGS. 7 to 9, support portions 51 to 54 are provided on the inner peripheral side of the insulating case 5, and the through conductors 21 and 22 are supported by the support portions 51 to 54. . In this case, since the through conductors 21 and 22 can be supported by the insulating case 5, the filling amount of the insulating filler 41 is reduced, and deterioration of the pressure resistance characteristics due to the thermal expansion / contraction stress of the insulating filler 41 is avoided. Cost reduction can be achieved.

  10 is a partially broken sectional view showing an embodiment of the magnetron according to the present invention, and FIG. 11 is an electric circuit diagram of the magnetron shown in FIG. FIG. 10 shows, for example, a magnetron for a microwave oven, and includes a filter box 84, a cathode stem 85, and a high-voltage feedthrough capacitor 9.

  The filter box 84 is disposed so as to cover the cathode stem 85 and is connected to the ground electrode GND (see FIG. 10). The filter box 84 includes a cooling fin 842, a gasket 843, an RF output end 844, and a magnet 845.

  The high-voltage feedthrough capacitor 9 is provided through a through hole provided in the side plate 841 of the filter box 84, and the grounding metal 3 is electrically and mechanically connected to the side plate 841.

  The inductors 81 and 82 are connected to the cathode terminal of the cathode stem 85 and the high-voltage feedthrough capacitor 9 inside the filter box 84.

  In FIG. 11, the high-voltage feedthrough capacitor 9 forms a filter together with inductors 81 and 82. Each of the inductors 81 and 82 has one end led to the oscillator 83 and the other end led to each of the divided electrodes 12 and 13.

In the magnetron, for example, a commercial voltage or a high voltage of about 4 kV _0-P having a frequency of about 20 kHz to 40 kHz is applied to the through conductors 21 and 22. As a result, the magnetron oscillates, but at this time, noise is generated. The generated noise is reduced by the filter action of the high voltage feedthrough capacitor.

  Although the contents of the present invention have been specifically described above with reference to the preferred embodiments, it is obvious that those skilled in the art can take various modifications based on the basic technical idea and teachings of the present invention. It is.

It is a top view which shows one Example of the capacitor | condenser which concerns on this invention. FIG. 2 is a sectional view taken along line 2-2 of FIG. FIG. 3 is a sectional view taken along line 3-3 in FIG. 1. FIG. 4 is a partially enlarged cross-sectional view of the high-voltage feedthrough capacitor shown in FIGS. 1 to 3. It is sectional drawing which shows the insulation filler casting process of the high voltage feedthrough type capacitor which concerns on this invention. It is sectional drawing in another Example of the high voltage feedthrough capacitor which concerns on this invention. It is a top view in another Example of the high voltage feedthrough capacitor based on this invention. FIG. 8 is a cross-sectional view taken along line 8-8 in FIG. 7. FIG. 9 is a cross-sectional view taken along line 9-9 in FIG. 7. It is a fragmentary broken sectional view which shows one Example of the magnetron based on this invention. It is an electric circuit diagram of the magnetron shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Capacitor 12, 13 Divided electrode 14 Common electrode 21, 22 Through conductor 3 Grounding metal fitting 30 Recess 32 Lifting part 6 Insulating cover 61 Fitting part 62 Cylindrical part 63 Partition part

Claims (4)

A high-voltage feedthrough capacitor including a grounding fitting, a capacitor, an insulating cover, a through conductor, an insulating filler, and an insulating tube,
The grounding metal has a raised part on one side, and the raised part has a recess on the other side,
The capacitor has two through holes, has two divided electrodes on one surface side where the through holes are open, has a common electrode on the other surface side, and is mounted on one surface of the raised portion, A common electrode is connected to the one surface of the raised portion;
The insulating cover has a partition portion on one end side, and one end side with the partition portion is closely fitted to the inner surface of the concave portion of the ground metal fitting,
The through conductors are two, each connected to the divided electrode, led through the capacitor, the grounding metal fitting and the partition part,
The insulating filler is filled inside and outside the capacitor,
There are two insulating tubes, each covering the through conductor on the capacitor side of the partition portion, and the end portion is abutted against the through portion of the through conductor in the partition portion to prevent leakage. Constitute,
High voltage feedthrough capacitor. The high-voltage through-type capacitor according to claim 1, further comprising two electrode connection bodies, each of the electrode connection bodies having a through hole, straddling the through hole of the capacitor, Connected to each of the divided electrodes, the through hole is continuous with the through hole,
The through conductor is connected to each of the electrode connectors,
The insulating tube is pressed between the electrode connector and the partition part,
High voltage feedthrough capacitor. A high-voltage feedthrough capacitor according to claim 2,
The partition part has a cylindrical part in a portion through which the through conductor passes.
The insulating tube is pressed between the electrode connector and the bottom of the cylindrical part,
High voltage feedthrough capacitor. A magnetron including a high voltage feedthrough capacitor,
The high-voltage feedthrough capacitor is the one described in claim 1 or 2, and is incorporated as a filter.
Magnetron.

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