JPH06815Y2 - Feedthrough capacitor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to a high withstand voltage feed-through capacitor used as a noise filter for a high frequency and high power device such as a microwave oven, a magnetron for broadcasting, or an X-ray tube. With regard to a through-type capacitor in which a feedthrough capacitor fixed to one surface of a grounding metal is surrounded by an insulating case, and a feedthrough capacitor surrounded by the insulating case is filled with an insulating resin, a tube having a major axis direction and a minor axis direction is provided. By arranging the plate-shaped terminal part of the through conductor in a striped insulating case so that the plate surface is parallel to the major axis direction of the insulating case, it is insulated from the terminal part of the through conductor that becomes the high voltage generating part. The space distance between the case and the case is increased to increase the creepage distance from the terminal portion to the grounding metal to increase the pressure resistance and improve the burnout resistance.

<Prior Art> FIG. 6 is an exploded perspective view of a conventional feedthrough capacitor, FIG. 7 is a front partial sectional view of the same, and FIG. 8 is a side sectional view of the same. The common electrode 6 of the through-hole porcelain capacitor 1 having the electrodes 4 and 5 and the common electrode 6 which are independent from each other is fixed to the floating portion 71 of the grounding metal 7 by means of soldering or the like, on both sides of the opening. 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 through ceramic capacitor 1 and the through hole 8 of the grounding metal 7, and the through conductors 11 and 1 are penetrated.
2 is attached to the electrode connectors 13 and 14 fixed to the electrodes 4 and 5 of the through-hole porcelain capacitor 1 by soldering by means such as soldering.

Since the through-hole porcelain capacitor 1 has through-holes 2 and 3 arranged side by side, a direction in which the through-holes 2 and 3 are present is defined as a major axis direction, and a direction orthogonal to this is defined as a minor axis direction. The outer peripheral surfaces of both ends are formed in a semi-circular shape, and both end portions of the semi-arcuate shape are connected by parallel planes.

The grounding metal 7 is formed by subjecting a metal plate material such as an iron plate to a drawing process so that a floating portion 71, which rises at an appropriate height from a flat outer peripheral edge, is projected at an intermediate portion on the one surface side to float. The insulating case 17 is attached to the outer periphery of the portion 71 so as to surround the through-hole porcelain condenser 1, and the other surface side is
The insulating cover 18 is provided so as to surround the through conductors 11 and 12.
Is attached. The plane shape of the floating portion 71 of the grounding metal 7 and the inner diameter shape of the insulating case 17 are substantially similar to the outer shape of the through-hole porcelain capacitor 1 and have a major axis direction and a minor axis direction. Then, the inside and outside of the through-hole porcelain capacitor 1 surrounded by the insulating case 17 and the insulating cover 18 are filled with an externally filled insulating resin 15 and an internally filled insulating green resin 16 made of epoxy resin or the like to secure moisture resistance and insulation. There is.

Flat terminal portions 111 and 121, such as Faston tab connectors, which project outward from the surface 151 of the insulating resin 15 are formed at the ends of the through conductors 11 and 12 on the insulating case 17 side. The terminal portions 111 and 121 are arranged so that the width direction thereof coincides with the short diameter direction of the insulating case 17.

The insulating case 17 is generally formed in a tubular shape using a thermoplastic insulating resin such as PBT.

FIG. 9 is a partial cross-sectional view when the feedthrough capacitor described above is used as a magnetron filter, and 19 is a filter box. In the feedthrough capacitor, the grounding metal 7 is attached and fixed to the filter box 19.

<Problems to be Solved by the Invention> As described above, conventionally, the cylindrical insulating case 17 having an inner diameter having a major axis direction and a minor axis direction is used, and the surface 151 of the insulating resin 15 is removed from the surface 151. Since the flat plate-shaped terminal portions 111 and 121 protruding to the outside are arranged so that the dimensionally long width direction thereof coincides with the short diameter direction of the insulating case 17,
The spatial distance G ₁ from the ends of the terminal portions 111 and 121 to the inner wall surface of the insulating case 17 becomes short.

Moreover, as shown in FIG. 9, when the feedthrough capacitor is used in a magnetron of a microwave oven, the environment of use is high, such as in a kitchen or kitchen, and the oil smoke,
It becomes a place with lots of garbage and dust. In this way, in addition to the bad working environment, a high voltage is applied to generate an electrostatic force, so that the surface 151 of the insulating resin 15 and the surface of the insulating case 17 contain oil fumes, dust, dust (b) in the atmosphere. Adheres. In particular,
Since the spatial distance G ₁ from the end portions of the terminals 111 and 121 to the inner wall surface of the insulating case 17 in the minor axis direction is short as described above, this portion is easily clogged with oil smoke, dust, and dust (B). When dew condensation is caused by a change in ambient temperature, the surface 151 of the insulating resin 15 and the surface of the insulating case 17 become hygroscopic,
The surface resistance is significantly reduced.

Therefore, due to a narrow space distance G ₁ between the terminal portions 111 and 121 and the insulating case 17, the surface 151 of the insulating resin 15 and the oil smoke adhering to the surface of the insulating case 17, dust, dust (b), and moisture absorption due to dew condensation. , Creeping discharge is generated in a path (a) from the terminal portions 111 and 121 to the grounding metal 7 through the surface 151 of the external filling insulating resin 15 and the surface of the insulating case 17.
There is a problem in that the insulating case 17 is burnt out.

As a means for preventing a burnout accident, it is known that the insulating case 17 is made of flame-retardant thermosetting resin or porcelain. In this case, the filling and hardening of the external filling insulating resin 15 made of epoxy resin is performed. Insulation case 1 in the treatment process
The outer filling insulating resin 15 strongly adheres to the inner surface of 7, and tensile stress is generated in the outer filling insulating resin 15 toward the insulating case 17. Therefore, there is a problem that peeling occurs at the interface between the externally filled insulating resin 15 and the through-hole porcelain capacitor 1 and a breakdown voltage defect occurs.

<Means for Solving the Problems> In order to solve the above problems, the present invention provides a feedthrough capacitor including a grounding metal fitting, a feedthrough capacitor, an insulating case, an insulating resin, an electrode connector, and a feedthrough conductor. There, the grounding metal is composed of a plate material, and has a floating portion on one surface side, the through-capacitor has electrodes on both surfaces facing each other, and a through-hole penetrating in the direction of both surfaces. One of the electrodes is fixed on the surface of the floating portion of the grounding metal and is mounted on the grounding metal, and the insulating case has an inner diameter in a major axis direction and a minor axis direction. It is formed in a tubular shape and is arranged so as to surround the feedthrough capacitor, the insulating resin is filled around the feedthrough capacitor surrounded by the insulating case, and the electrode connection body is formed through the feedthrough. Ko It is connected to the other of the electrodes of the denser, the through conductor has a terminal portion, and a through conductor portion, is connected to the other of the electrodes of the through capacitor via the electrode connection body, The terminal portion is plate-shaped, is projected and led out of the insulating resin above the electrode connector, and is arranged so that a width direction thereof coincides with a major axis direction of the insulating case. The conductor portion is formed in the shape of a rod whose width is sufficiently smaller than the width of the terminal portion and whose difference between the width and the thickness is sufficiently smaller than the difference between the width and the thickness of the terminal portion. Penetrates through.

<Action> The feedthrough capacitor has electrodes on opposite sides, and one of the electrodes is fixed on the surface of the floating part of the grounding metal fitting and is mounted on the grounding metal fitting. Since the terminal part of the through conductor is connected to the other side of the electrode and the terminal part projects out above the electrode connector, the terminal part of the through conductor is located on the side of the through capacitor that is installed on the grounding metal fitting. To do. Due to this structure, it is possible to position the terminal portion outside the magnetron or the like and receive the connector assembled from the outside with the terminal portion as it is. Further, since the feedthrough capacitor is located in the same direction as the terminal portion of the feedthrough conductor, when the terminal portion is located outside the magnetron or the like, the feedthrough capacitor is also located outside the magnetron. Therefore, it is possible to easily connect the external connector to the terminal portion and avoid the adverse effect of the magnetron internal atmosphere on the feedthrough capacitor.

The insulating resin is filled around the feedthrough capacitor surrounded by the insulating case, and the terminal portion of the feedthrough conductor is projected and led out to the outside of the insulating resin above the electrode connector, so that the terminal portion of the feedthrough conductor is Reinforce with insulating resin,
In particular, it is possible to ensure the mechanical strength that can sufficiently resist the external force when the external connector is inserted and removed.

The insulating case is formed in a cylindrical shape having an inner diameter having a major axis direction and a minor axis direction, and the terminal portion of the through conductor is plate-shaped and arranged so that the width direction thereof coincides with the major axis direction of the insulating case. Therefore, it is possible to increase the spatial distance from the terminal portion to the inner surface of the insulating case. Therefore, the feedthrough capacitor has a structure in which it is located in the same direction as the terminal portion of the feedthrough conductor, and in the structure surrounded by the insulating case, even if oil smoke, dust, dust, or the like adheres to the insulating case, the burnout accident can be ensured. It can be prevented.

Since the penetrating conductor portion is formed in a rod shape whose width is sufficiently smaller than the width of the terminal portion and whose difference between the width and thickness is sufficiently smaller than the difference between the width and thickness of the terminal portion, the penetrating conductor portion The volume reduction of the dielectric porcelain due to the portion can be suppressed to the minimum. Therefore, in this type of feedthrough capacitor that uses feedthrough capacitors having electrodes on opposite sides, the capacitance does not decrease due to the volume reduction of the dielectric porcelain.

Therefore, it is possible to obtain a feedthrough capacitor in which the withstand voltage is improved by the terminal portion and the capacitance is prevented from decreasing.

<Embodiment> FIG. 1 is a partial front sectional view of a feedthrough capacitor according to the present invention, FIG. 2 is a partial side sectional view thereof, and FIG. 3 is a plan view thereof. In the figure, the same reference numerals as those in FIGS. 6 to 8 denote the same components. Similarly to the conventional case, the through-hole porcelain capacitor 1 is provided with two through-holes 2 and 3 spaced apart in the major axis direction, and the through-hole conductors 11 and 12 are provided for the through-holes 2 and 3, respectively.
The outer peripheral surfaces of the both ends in the major axis direction are formed in a semi-circular shape, and the outer peripheral surface in the minor axis direction is formed into a flat shape. A case 17 is arranged.

As in the conventional case, the insulating case 17 is made of a thermoplastic insulating resin such as PBT and is formed in a tubular shape having an inner diameter in the major axis direction and a minor axis direction. The through conductors 11 and 12 are the grounding metal 7
The plate-shaped terminal portions 111, 121 protruding outward from the surface 151 of the insulating resin 15 above the electrode connecting bodies 13, 14 located on the opposite side to the insulating case 17 are arranged in the width direction.
Are arranged so as to coincide with the major axis direction of. That is, compared with the conventional structure, the structure is rotated by 90 degrees.

Therefore, in the terminal portions 111 and 121, the dimensionally long width direction is aligned with the major axis direction of the insulating case 17, and the dimensionally short plate thickness direction is aligned with the minor axis direction. For this reason, not only the spatial distance A in the major axis direction from the terminal portions 111 and 121 to the inner surface of the insulating case 17 but also the spatial distance B in the minor axis direction can be made large, and the insulating case 17 can be covered with oil smoke. Even if dust, dust, or the like adheres, the creeping discharge can be prevented and the burnout accident can be reliably prevented. It is desirable that the spatial distances A and B be substantially equal so that the spatial distances in all directions are uniform.

The penetrating conductor portions 112, 122 have a width that is sufficiently smaller than the width of the terminal portions 111, 121, and the difference between the width and the thickness is sufficiently smaller than the difference between the width and thickness of the terminal portions 111, 121. Is formed in. Therefore, it is possible to minimize the volume reduction of the dielectric ceramic due to the penetrating conductors 112 and 122. For this reason, in this type of feedthrough capacitor using feedthrough capacitors having electrodes 4 and 5 on opposite sides, the capacity is not reduced due to the volume reduction of the dielectric ceramic.

When the feedthrough capacitor according to the present invention is incorporated as a filter such as a magnetron, it has a mounting structure as shown in FIG. 4, and the surfaces of the terminal portions 111 and 121 in the plate thickness direction are parallel to the floor surface. Is installed.

FIG. 5 is a diagram showing humidification withstand voltage test data of a feedthrough capacitor according to the present invention (product of the present invention) and a conventional feedthrough capacitor (conventional product). The humidification pressure test is a model experiment in which a feedthrough capacitor is attached to the filter box of the magnetron of a microwave oven, continuous humidification is performed using an ultrasonic humidifier, and the microwave oven is turned on and off to intermittently apply voltage. Was done.

As is clear from the test data of FIG. 5, the cumulative failure rate exceeds 90% in 350 hours in the conventional product. On the other hand, in the product of the present invention, the cumulative failure rate is zero at 350 hours. It is only about 10% or less of failure at 700 hours, which is twice that, and it can be seen that the moisture resistance and pressure resistance characteristics are remarkably improved.

<Effect of the Invention> As described above, according to the present invention, the following effects can be obtained.

(A) It is possible to provide a feedthrough capacitor in which the terminal portion is located outside the magnetron or the like, and the connector assembled from the outside can be directly received by the terminal portion. Further, since the feedthrough capacitor is located in the same direction as the terminal portion of the feedthrough conductor, when the terminal portion is located outside the magnetron, etc.,
The feedthrough capacitor is also located outside the magnetron or the like. For this reason, it is possible to provide a feedthrough capacitor which can easily connect the external connector to the terminal portion and can avoid the adverse effect of the magnetron internal atmosphere on the feedthrough capacitor.

(B) The terminal portion of the penetrating conductor is reinforced with an insulating resin, and in particular, it is possible to secure mechanical strength that can sufficiently oppose external force when the external connector is inserted and removed.

(C) In a feedthrough capacitor having a structure in which the space distance from the terminal portion to the inner surface of the insulating case is large and the feedthrough capacitor is located in the same direction as the terminal portion of the feedthrough conductor, the feedthrough capacitor is surrounded by the insulating case. Even if oily smoke, dust, dust, etc. adhere to the case, it is possible to reliably prevent a burnout accident.

(D) It is possible to minimize the volume reduction of the dielectric ceramic due to the penetrating conductor portion. Therefore, in this type of feedthrough capacitor that uses feedthrough capacitors having electrodes on opposite sides, the capacitance does not decrease due to the volume reduction of the dielectric porcelain. As a result, it is possible to provide a feedthrough capacitor in which the withstand voltage is improved by the terminal portion and the capacitance is prevented from decreasing.

[Brief description of drawings]

1 is a front partial sectional view, FIG. 2 is a side partial sectional view of the same, FIG. 3 is a plan view of the same, and FIG. 4 shows a state in which the feedthrough capacitor according to the present invention is used as a magnetron filter. 5 and 5 are views showing humidification withstand voltage test data of a feedthrough capacitor according to the present invention (product of the present invention) and a conventional feedthrough capacitor (conventional product), and FIG. 6 is an exploded perspective view of the conventional feedthrough capacitor. FIG. 7 is a front partial sectional view of the same, FIG. 8 is a side partial sectional view of the same, and FIG. 9 is a diagram showing a state in which a conventional feedthrough capacitor is used as a magnetron filter. 1 ... Feed-through capacitor 4, 5, 6 ... Electrode 7 ... Grounding metal fitting 11, 12 ... Feed-through conductor 15 ... Insulating resin 17 ... Insulation case 111, 121 ... Terminal part

Claims (4)

[Scope of utility model registration request] 1. A through-type capacitor including a grounding metal fitting, a feedthrough capacitor, an insulating case, an insulating resin, an electrode connector, and a feedthrough conductor, wherein the grounding metal fitting is made of a plate material, and one surface side thereof is provided. The feedthrough capacitor has electrodes on both surfaces facing each other, and has a through hole penetrating in the direction of both sides, and one of the electrodes is the floating portion of the grounding metal. Fixed on the surface of the part and mounted on the grounding metal, the insulating case is formed in a tubular shape having an inner diameter in a major axis direction and a minor axis direction, and is arranged so as to surround the feedthrough capacitor. The insulating resin is filled around the feedthrough capacitor surrounded by the insulating case, the electrode connection body is connected to the other of the electrodes of the feedthrough capacitor, The body has a terminal portion and a through conductor portion, and is connected to the other of the electrodes of the through capacitor via the electrode connecting body, and the terminal portion is plate-shaped, and the electrode connection is provided. It is projected to the outside of the insulating resin above the body and is arranged so that the width direction matches the major axis direction of the insulating case, and the through conductor portion has a width sufficiently larger than the width of the terminal portion. A through-type capacitor that is formed into a rod shape having a very small difference in width and thickness sufficiently smaller than a difference in width and thickness of the terminal portion and penetrates through the through hole. 2. The feedthrough capacitor has two through holes provided in parallel with each other in a major axis direction and a minor axis direction and spaced from each other in the major axis direction, and the through conductor is provided for each of the through holes. The feed-through capacitor according to claim 1, which is provided with the utility model registration claim. 3. The feedthrough capacitor has arcuate outer peripheral surfaces at both ends in the major axis direction, and both outer peripheral surfaces in the minor axis direction are flat, and the insulating case has the same tubular shape as the feedthrough capacitor. The feedthrough capacitor according to claim 2 which is located in the utility model registration claim. 4. The penetration according to claim 3, wherein the spatial distance in the minor axis direction from the end portion of the terminal portion to the inner wall surface of the insulating case is substantially equal to the spatial distance in the major axis direction. Shaped capacitors.