JP2561721Y2 - High voltage capacitors and magnetrons - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetron having a high-voltage capacitor and a filter comprising the high-voltage capacitor.

[0002]

2. Description of the Related Art As a conventional high-voltage capacitor of this type, for example, as shown in Japanese Utility Model Publication No. 1-18838 and Japanese Utility Model Publication No. 63-48112, two through holes are provided in one through capacitor. Formed at an interval, provided on each side of the through-hole opened a separate electrode independent of each other and a common electrode common to the individual electrodes, the common electrode,
It is fixed on the floating portion of the grounding metal by means such as soldering, and a through conductor covered with an insulating tube is passed through the through hole of the through capacitor and the through hole of the grounding metal. On the individual electrodes of
The twin type soldered using an electrode connector or the like is the best known. The grounding metal has a floating part protruding at the center or the central part on one side, and an insulating case is inserted around the floating part so as to surround the feedthrough capacitor, and a penetrating conductor is formed on the other side. An insulating cover is inserted so as to surround the. The inside and outside of the feedthrough capacitor surrounded by the insulating case and the insulating cover are filled with an epoxy resin or the like to ensure moisture resistance and insulation. A terminal portion such as a tab connector is formed at the end of the through conductor on the insulating case side.

[0003]

However, since the conventional high-voltage capacitor uses one feed-through capacitor and is filled with an insulating resin inside and outside, the contact interface between the feed-through capacitor and the insulating resin is reduced. Widely spreads on the inner and outer circumferences. For this reason, the probability of occurrence of interface delamination increases, and a withstand voltage failure is easily caused. In addition, since a double-type feedthrough capacitor is used and the surrounding area is filled with an insulating resin, there is a limit to miniaturization of the shape. Further, the use of a double feedthrough capacitor increases the cost. The magnetron using the above-mentioned high-voltage capacitor also has the above problem.

[0004] In order to avoid the above-mentioned problems, a capacitor-independent high-voltage capacitor using two feed-through capacitors, which became mainstream before the dual type was proposed, was reviewed. However, the capacitor-independent high-voltage capacitor has the following problems. (A) Since the feedthrough capacitors are independent of each other, the mechanical strength when fixing them on the grounding metal becomes insufficient. The feedthrough capacitor is equipped with a feedthrough conductor, and an external connector is inserted and removed from the tab terminal of this feedthrough conductor.
If the mechanical strength is insufficient, the through conductor becomes uneven, the interface peels off between the through conductor, the dielectric and the grounding metal, and the insulating resin, and the withstand voltage characteristic is largely deteriorated. (B) Even if an insulating case is arranged for each feedthrough capacitor and a structure such as filling an insulating resin around the feedthrough capacitor in the insulating case is adopted, it can sufficiently oppose an external force when an external connector is connected. It was difficult to secure mechanical strength. (C) Since the insulating resin must be individually filled for each insulating case, the number of steps for casting the insulating resin increases, which leads to an increase in cost. (D) When water droplets or the like adhere to the surface of the insulating case, they are likely to be formed along the surface of the insulating case, which may cause a withstand voltage defect. This type of high-voltage capacitor has an important application as a filter for a magnetron of a microwave oven, and is often used in a humid or dusty environment. Therefore, a high humidification withstand voltage level is required. (E) For example, Japanese Utility Model Publication No. 1-19388, Japanese Utility Model Publication No. 63
Japanese Patent No. 48112 discloses a structure in which two feedthrough capacitors are covered with one insulating case and the inside thereof is filled with an insulating resin. Is filled with an insulating resin more than necessary, the thermal stress applied in a heat cycle test or the like increases, and the risk of causing a withstand voltage defect or the like increases. In addition, the overall shape is increased in size and cost is increased.

Accordingly, an object of the present invention is to solve the above-mentioned conventional problems and to provide a small and inexpensive high-voltage capacitor having high mechanical strength, high withstand voltage characteristics including humidification withstand voltage characteristics. And a magnetron.

[0006]

In order to solve the above-mentioned problem,
The high-voltage capacitor according to the present invention is a high-voltage capacitor having a grounding fitting, a feedthrough capacitor, a through conductor, an insulating case, and an insulating resin, wherein the grounding fitting has two floating surfaces on the same surface side. And each of the floating portions has a hole in the center and is arranged at a distance from each other, and the number of the through capacitors is two, each having a through hole, and Electrodes are provided on both surfaces that are open, and one of the electrodes is fixed to the floating portion, and the through conductor penetrates through the through hole for each of the through capacitors. Prepared and
Each is individually conductively connected to the other of the electrodes, the insulating case has two tubular portions, the tubular portions are juxtaposed at an interval from each other, and the upper opening sides of the tubular portions are connected to each other. A concave portion connected to the inner diameter portion, a lower opening side is inserted into the outer periphery of the floating portion, and the through capacitor is housed in the inner diameter portion; and the insulating resin is provided around the through capacitor in the inner diameter portion. Is filled.

[0007]

The grounding metal fitting has two raised portions on the same surface side, two through capacitors, each having a through hole, and having electrodes on both surfaces where the through hole is opened. , One of the electrodes is fixed to the floating portion and is disposed on the floating portion, and the through conductor is provided to penetrate through the through hole for each of the penetrating capacitors, and each is individually conductively connected to the other of the electrodes. It is a capacitor-independent high-voltage capacitor because it is
The probability of occurrence of interface delamination is reduced, and withstand voltage failure is less likely to occur, and the size and cost are reduced.

[0008] The insulating case has two cylindrical portions, and accommodates a through capacitor in the inner diameter portion of the cylindrical portion. Since the insulating resin is filled around the through capacitor in the inner diameter portion,
As in the conventional case, the moisture resistance and the insulating property of the insulating resin can be ensured. Only the required minimum amount of the insulating resin is injected into each cylinder, and the insulation resin is substantially independent between the cylinders.
For this reason, thermal stress applied at the time of mounting in a microwave oven, a heat cycle test or the like is reduced, and a withstand voltage defect or the like is hardly generated.

The insulating case has an upper opening side of the two cylindrical portions connected to each other, and a lower opening side is inserted into the outer periphery of the floating portion on the grounding metal fitting. Is obtained. For this reason, the mechanical reinforcement of the penetrating capacitor and the penetrating conductor housed in the inner diameter part of the cylindrical part increases, and the penetrating conductor is less likely to be uneven. As a result, the through conductor, the dielectric and the grounding metal,
Interfacial separation with the insulating resin is less likely to occur, and the withstand voltage characteristics are significantly improved.

The insulating case has a concave portion in which the upper opening side of the two cylindrical portions is continuous with the inner diameter portion.
Insulating resin can be simultaneously poured into the two cylindrical portions. For this reason,
Compared to a conventional capacitor-independent high-voltage capacitor which has to be individually filled with an insulating resin for each insulating case, the number of steps for casting the insulating resin is reduced by half, and the cost is reduced.

The insulating case has a concave portion in which the upper opening side of the two cylindrical portions is continuous with the inner diameter portion. Therefore, when water droplets or the like adhere to the surface of the insulating case, the concave portion is grounded to the through conductor positioned inside the insulating case. A barrier that prevents surface leakage between the metal fittings. Therefore, a high-voltage capacitor having a high humidification withstand voltage level can be obtained even when used in an environment with a lot of moisture or dust, such as a filter of a magnetron of a microwave oven.

The insulating case has two cylindrical portions, and the cylindrical portions are juxtaposed at an interval from each other. Therefore, a space generated between the cylindrical portions serves as a heat radiation area, and is used for mounting in a microwave oven, a heat cycle test, and the like. , The thermal stress applied is small, and a withstand voltage failure or the like is unlikely to occur.

[0013]

1 is a front sectional view of a high-voltage capacitor according to the present invention, FIG. 2 is a plan view of the same, and FIG. 1 is a grounding bracket, 2 and 3 are feedthrough capacitors,
4, 5 are through conductors, 6 is an insulating case, 71 and 72 are insulating resins, 81 and 82 are insulating resins, 9 is an insulating cover,
11 is an insulating tube.

The grounding metal fitting 1 has two raised portions 101 and 102 on the same surface side, and each of the raised portions 101 and 102 has holes 103 and 104 at the center, and is arranged at an interval from each other. ing.

There are two through capacitors 2 and 3, each having through holes 201 and 301, and electrodes (202 and 20) on both surfaces where the through holes 201 and 301 are opened.
3), (302, 303), and the floating portions 101, 1
02 and the electrodes 203 and 303 are
1, 102 are fixed by means such as soldering. The feedthrough capacitors 2 and 3 are made of dielectric porcelain.

The through conductors 4 and 5 are connected to the through capacitors 2 and 3
Each is provided so as to penetrate through the inside of the through-holes 201 and 301, and each is individually and electrically connected to the electrodes 202 and 302. The through conductors 4, 5 are provided at the raised portions 101, 1, 1
Both ends are led to the outside through holes 103 and 104 provided in the hole 02 in a non-contact state. Reference numerals 12 and 13 denote electrode fittings for connecting the through conductors 4 and 5 and the electrodes 202 and 302. Tab terminal portions 41 and 51 are provided on the upper end side (in the figure) of the through conductors 4 and 5.

The insulating case 6 has two cylindrical portions 61 and 62, and the cylindrical portions 61 and 62 are juxtaposed with an interval D therebetween. The insulating case 6 has upper opening sides of the cylindrical portions 61 and 62 connected to each other by a connecting portion 64, and an inner diameter portion 611,
621, the lower opening side is inserted into the outer periphery of the raised portions 101, 102, and the inner diameter portions 611, 62
The feedthrough capacitors 2 and 3 are housed in the unit 1.

The insulating resins 71 and 72 have inner diameter portions 611 and 62.
1 are filled around the feedthrough capacitors 2 and 3.
The filling region of the insulating resins 71 and 72 is suitably located at a position not so far up and down with respect to the connecting portion 64 of the insulating case 6. The insulating resins 81 and 82 are filled in the region on the opposite side with the grounding metal 1 therebetween. Insulating resin layer (71, 7
2) and (81, 82) can be constituted by a thermosetting resin or a thermoplastic resin which is a polymer resin, or a composite resin obtained by mixing these resins with an inorganic filler.

As described above, the grounding metal fitting 1 is
There are two floating portions 101 and 102, and two feedthrough capacitors 2 and 3 are provided.
And electrodes (202, 203) and (302, 303) on both sides where the through holes 201 and 301 are opened.
2 and 302 are fixed to the raised portions 101 and 102, and the through conductors 4 and 5 are provided through the through holes 201 and 301 for each of the through capacitors 2 and 3, and each is provided with an electrode 2.
02 and 302 are individually connected to each other, so that the capacitor becomes a capacitor-independent high-voltage capacitor, the probability of occurrence of interface delamination is reduced, and a withstand voltage failure is less likely to occur as compared with a dual-type high-voltage capacitor. It is small in size and inexpensive.

The insulating case 6 houses the feedthrough capacitors 2 and 3 in the inner diameter portions of the two cylindrical portions 61 and 62, and the insulating resins 71 and 72 surround the feedthrough capacitors 2 and 3 in the inner diameter portions 611 and 621. Since it is filled, the insulating resin 71,
Thus, the moisture resistance and the insulating property can be secured. Insulating resin 7
1 and 72 are injected only in the necessary minimum amount only in each of the cylinder portions 61 and 62, and are substantially independent between the cylinder portions 61 and 62. In addition, since the insulating case 6 has the two cylindrical portions 61 and 62 juxtaposed at a distance D from each other, the space 14 generated between the cylindrical portions 61 and 62 serves as a heat radiation area, and is used when mounting the microwave oven. The thermal stress applied in a heat cycle test or the like becomes small, and it becomes difficult to generate a withstand voltage defect or the like.

The insulating case 6 has two cylindrical portions 61 and 62 whose upper opening sides are connected to each other and whose lower opening side is above the grounding bracket 1.
Are mounted on the outer periphery of the raised portions 101 and 102, so that an assembling structure in which the insulating case 6 is integrally connected vertically is obtained. For this reason, the inner diameter portions 611 of the cylindrical portions 61 and 62,
The mechanical reinforcement of the feedthrough capacitors 2, 3 and the feedthrough conductors 4, 5 housed in the 621 increases, and it is difficult for the feedthrough conductors 4, 5 to become uneven. As a result, interface peeling between the through-conductors 4 and 5, the through-capacitors 2 and 3, and the grounding metal 1 and the insulating resins 71 and 72 is less likely to occur.
The withstand voltage characteristics are greatly improved.

The insulating case 6 has a concave portion 63 in which the upper opening sides of the two cylindrical portions 61 and 62 are continuous with the inner diameter portions 611 and 621.
The insulating resin 71 and 72 can be simultaneously cast into the 62. For this reason, the number of insulating resin casting steps is reduced by half, and cost reduction is achieved.

The insulating case 6 has a concave portion 63 in which the upper opening sides of the two cylindrical portions 61 and 62 are continuous with the inner diameter portions 611 and 621. Therefore, when water droplets a or the like adhere to the surface of the insulating case 6, the concave portion is formed. The flange 631 of 63 serves as a barrier for preventing leakage between the through conductors 4 and 5 located inside and the grounding metal fitting 1. For this reason, a high-voltage capacitor having a high humidification withstand voltage level that can sufficiently withstand use can be obtained even when used in an environment with a lot of moisture or dust, such as a filter of a magnetron of a microwave oven.

FIG. 4 is a partial sectional view of a magnetron incorporating a high-voltage capacitor according to the present invention as a filter.
15 is a cathode stem, 16 is a filter box, 17, 1
8 is an inductor, and 19 is a high voltage capacitor according to the present invention used as a filter together with the inductors 17 and 18. The filter box 16 is disposed so as to cover the cathode stem 15, and the high-voltage capacitor 19 is provided through a through hole provided in the side plate 161 of the filter box 16 so that the insulating case 6 is exposed to the outside. The grounding bracket 1 is attached to and fixed to the side plate 161 of the filter box 16. Inductor 17, 1
Reference numeral 8 is connected in series between the cathode terminal of the cathode stem 15 and the through conductors 4 and 5 of the high-voltage capacitor 19 inside the filter box 16. 20 is a magnet, 2
1 is a cooling fin, 22 is a gasket, and 23 is an RF output terminal.

[0025]

As described above, according to the present invention, the following effects can be obtained. (A) The grounding metal has two floating portions on the same surface side, and two through capacitors each having a through hole and having electrodes on both surfaces where the through hole is opened, and a floating portion. One of the electrodes is fixed to the floating portion, and the through conductor is provided through the through hole for each of the through capacitors, and each is individually conductively connected to the other of the electrodes. It is possible to provide a small and inexpensive high-voltage capacitor and a magnetron that have a low probability of occurrence of peeling and are unlikely to cause withstand voltage failure. (B) The insulating case houses the feedthrough capacitor in the inner diameter of the two cylindrical portions, and the insulating resin is filled around the feedthrough capacitor in the inner diameter portion. A high-voltage capacitor and a magnetron can be provided in which an insulating resin is cast in a substantially independent state between the cylindrical portions, a small thermal stress is applied at the time of mounting in a microwave oven, a heat cycle test and the like, and the voltage resistance is excellent. (C) In the insulating case, since the upper opening sides of the two cylindrical portions are connected to each other and the lower opening side is inserted into the outer periphery of the raised portion on the grounding metal fitting, the feedthrough capacitor and the feedthrough housed in the inner diameter portion of the cylindrical portion are provided. High quality, high reliability with increased mechanical reinforcement of conductors, preventing peeling of the interface between insulating resin and through conductors, through capacitors and grounding fittings due to unevenness of through conductors, and greatly improved withstand voltage characteristics High voltage capacitors and magnetrons can be provided. (D) Since the insulating case has a concave portion in which the upper opening side of the two cylindrical portions is continuous with the inner diameter portion, the number of steps of casting the insulating resin can be reduced by half, and a high-voltage capacitor and a magnetron with reduced costs can be provided. (E) Since the insulating case has a concave portion in which the upper opening sides of the two cylindrical portions are connected to the inner diameter portion, the insulating case has a high humidification withstand voltage level that can sufficiently withstand use even in a humid or dusty environment. High voltage capacitors and magnetrons can be provided. (F) In the insulating case, since the two cylindrical portions are provided side by side at an interval from each other, a space generated between the cylindrical portions serves as a heat radiating region, and a small thermal stress is applied during mounting in a microwave oven and a heat cycle test. It is possible to provide a high-voltage capacitor and a magnetron that are less likely to cause a withstand voltage failure or the like.

[Brief description of the drawings]

FIG. 1 is a front sectional view of a high-voltage capacitor according to the present invention.

FIG. 2 is a plan view of the high-voltage capacitor according to the present invention.

FIG. 3 is an external perspective view of the high-voltage capacitor according to the present invention.

FIG. 4 is a partial cutaway view of a magnetron incorporating the high-voltage capacitor according to the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 grounding fittings 101, 102 raised portions 103, 104 holes 2, 3 through capacitor 201, 301 through hole 202, 203 electrode 302, 303 electrode 4, 5 through conductor 6 insulating case 61, 62 cylindrical portion 63 concave portion 64 connecting portion 71 , 72 Insulating resin 9 Insulating cover 10, 11 Insulating tube 81, 82 Insulating resin

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Shigeru Ito 1-13-1 Nihonbashi, Chuo-ku, Tokyo TDK Corporation (72) Inventor Isao Fujiwara 1-13-1 Nihonbashi, Chuo-ku, Tokyo TDK Inside the corporation

Claims (2)

(57) [Scope of request for utility model registration] 1. A high-voltage capacitor comprising a grounding metal, a through capacitor, a through conductor, an insulating case, and an insulating resin, wherein the grounding metal has two floating portions on the same surface side. Each of the floating portions has a hole in the center thereof and is arranged at a distance from each other, the two through capacitors are each provided with a through hole, and both surfaces having a through hole are opened. One of the electrodes is disposed on the floating portion and one of the electrodes is fixed to the floating portion, and the through conductor is provided so as to penetrate through the through hole for each of the through capacitors. , Each of which is individually conductively connected to the other of the electrodes, the insulating case has two tubular portions, the tubular portions are juxtaposed at an interval from each other, and the upper opening sides of the tubular portions are connected to each other. And has a recess connected to the inner diameter The lower opening side is inserted into the outer periphery of the floating portion, the through capacitor is housed in the inner diameter portion, and the insulating resin is filled around the through capacitor in the inner diameter portion. And high voltage capacitor. 2. A magnetron having a filter made of a high-voltage capacitor, wherein the high-voltage capacitor has a grounding metal, a feedthrough capacitor, a feedthrough conductor, an insulating case, and an insulating resin. The grounding fitting has two raised portions on the same surface side, and each of the raised portions has a hole in a central portion and is arranged at an interval from each other,
There are two through capacitors, each having a through hole, and having electrodes on both surfaces where the through holes are opened, and one of the electrodes is disposed on the floating portion and one of the electrodes is in the floating portion. The through conductors are fixed to each other, and the through conductors are provided so as to penetrate through the through holes for each of the through capacitors. Each of the through conductors is individually electrically connected to the other of the electrodes. The cylindrical portion is provided side by side at an interval from each other, the upper opening side of the cylindrical portion has a recess connected to each other and connected to the inner diameter portion, the lower opening side is inserted into the outer periphery of the floating portion, The magnetron, wherein the through capacitor is housed in an inner diameter portion, and the insulating resin is filled around the through capacitor in the inner diameter portion.