JP2012160607A - Film capacitor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve a housing structure capable of maintaining compact size, light weight, and moisture proof and withstand voltage properties in order to obtain a high-capacity capacitor having a plurality of capacitor elements each using a metalized film in which metal vapor deposition electrodes are provided on a surface of a dielectric film.SOLUTION: A film capacitor is provided in which a plurality of capacitor elements each provided with metallikon electrodes on both ends and housed in a cylindrical case with open ends and the plurality of capacitor elements are arranged in parallel with one another and connected in parallel by external extraction terminals. The both end parts of the cylindrical cases are collectively covered with a pair of cavity-shaped terminal covers, respectively, and each of the cavity-shaped terminal cover is filled with an insulating resin inside.

Description

  The present invention relates to a film capacitor. In particular, the present invention relates to a film capacitor using a plurality of capacitor elements.

A film capacitor is a film of PP (polypropylene), PET (polyethylene terephthalate), PS (polystyrene), or the like, by depositing aluminum or zinc to form an electrode, and laminating or winding this to form a capacitor element, An aluminum foil electrode was laminated or wound together with a film to constitute a capacitor element. In the case of vapor-deposited metal, a metallicon electrode formed by metal spraying is applied to both ends of the capacitor element thus formed, a lead wire is welded or soldered to the metallicon electrode, and a terminal fitting is attached to the tip of the lead wire. The resin was poured into the container, and the capacitor elements and lead wires were filled with the resin.
In addition, large-capacity film capacitors used for vehicles, rolling mills, industrial equipment such as DC power transmission, power factor improvement, etc. use a plurality of capacitor elements, and externally extract the metallicon electrodes on the end faces of these capacitor elements. After being connected in parallel with terminals and housed in a container having an open top surface, the container was filled with an insulating resin.

  Further, in order to obtain a small size and light weight by eliminating the above-mentioned container and reducing the insulating resin filled in the container, Patent Document 1 discloses that an insulating adhesive resin tape is wound around the outer peripheral portion of the capacitor element, or After covering the heat-shrinkable resin tube, connect it in parallel, connect it in parallel with the external lead terminal, and then insulate the inside of the concave terminal cover with insulating resin so that both ends of the capacitor element are hidden together with a pair of concave terminal covers In order to fill and to maintain a gap between the pair of concave terminal covers, a film capacitor is described which has a pair of insulating plates provided at both ends of the concave terminal cover as a support column.

JP 2001-76966 A

The problem to be solved is that, in order to manufacture a large-capacity capacitor having a plurality of capacitor elements in a small size and light weight, an insulating adhesive resin tape is wound around the outer peripheral portion of the capacitor element as in Patent Document 1 or When a heat-shrinkable resin tube is provided, the capacitor element expands and contracts depending on the environment used at high and low temperatures, and the adhesive resin tape is displaced and the adhesive strength is reduced, so that the moisture resistance tends to deteriorate. . In addition, in the case of heat shrink resin tubes, if the thickness of the heat shrink resin tube is increased in order to improve moisture resistance, the capacitor element may be tightened more than necessary due to heat shrink, and the electrode spacing in the capacitor element may be increased. In some cases, the insulation resistance deteriorates due to pressure reduction or, in some cases, folding.
Further, as in Patent Document 1, in order to maintain a distance between a pair of concave terminal covers, when a pair of insulating plates are provided at both ends of the concave terminal cover to form a support, a support is provided at both ends as a capacitor. Since there is only a small, there is a structural restriction in strength, and it is difficult to increase the size.

  Therefore, an object of the present invention is to provide a film capacitor that is excellent in moisture resistance, insulation resistance and strength when manufacturing a large-capacity capacitor having a plurality of capacitor elements in a small size and light weight.

In order to solve the above problems, the present invention provides the following film capacitor.
(1) A plurality of capacitor elements each provided with a metallicon electrode at both ends are accommodated in a cylindrical case with both ends open, arranged in parallel, connected in parallel with an external lead terminal, and both end portions of the cylindrical case are connected to each other. A film capacitor that is covered with a pair of concave terminal covers to cover them all together, and the inside of the concave terminal cover is filled with an insulating resin.
(2) A plurality of capacitor elements each provided with metallicon electrodes at both ends are accommodated in a cylindrical case opened at both ends, arranged in parallel, connected in parallel with an external lead terminal, and both end portions of the cylindrical case are collectively A film capacitor that is covered with a pair of concave terminal covers so that the inside of the concave terminal cover and the inside of the cylindrical case are filled with an insulating resin.
(3) The film capacitor according to the above (1) or (2), having fixing means provided on the concave terminal cover for fixing the cylindrical case to the concave terminal cover.

  When manufacturing a large-capacity capacitor having a plurality of capacitor elements in a small and lightweight manner, a film capacitor having excellent moisture resistance, insulation resistance and strength can be provided.

1 is a cross-sectional view in the longitudinal direction of a capacitor showing an embodiment of the present invention. FIG. 5 shows a longitudinal sectional view of a capacitor showing another embodiment of the present invention. 1 is a cross-sectional view in the width direction of a capacitor showing an embodiment of the present invention. The example of the manufacturing method of this invention is shown.

In the capacitor element described in the present invention, a pair of metallized films provided with metal vapor deposition electrodes on the surface of a dielectric film such as a polypropylene film are alternately wound so that the metal surfaces do not overlap, and the wound both ends are wound. A metallicon electrode is formed on the part by a method such as thermal spraying of a metal such as zinc.
A metallicon electrode generally used for a film capacitor can be used, and is made of a metal or an alloy such as copper, zinc, aluminum, tin, or solder, and is formed by thermal spraying. In some cases, the surface of the electrode may be plated.
In addition to a capacitor element in which two metallized films with metallized vapor deposition electrodes formed on one side of a dielectric are rolled and wound, the present invention is not limited to this, but metallization with metal vapor deposition electrodes formed on both sides It may be a capacitor element produced by stacking and winding a film and a dielectric film on which no metal vapor deposition electrode is formed.

The cylindrical case described in the present invention is a cylindrical body that is open at both ends, and accommodates a capacitor element therein and protects it in terms of weather resistance and strength.
Materials include resin molded products such as PET (polyethylene terephthalate), PPS (polyphenylene sulfide), PPE (polyphenylene ether), PBT (polybutylene terephthalate), POM (polyoxymethylene), PPO (polyphenyl oxide), or polychlorinated. Vacuum resin molded products such as vinyl and polycarbonate, metals such as aluminum, iron, and stainless steel, or laminates of resin and metal. You don't have to worry about this. However, the adhesion at the resin / resin interface is often greater than the adhesion at the metal / resin interface, and in this respect, a resin molded product is preferable. Moreover, in the case of a fat molded product, you may reinforce with fillers, such as glass fiber. In the case of a laminate of a resin and a metal or a metal, it is necessary to have a structure in which the metal portion does not contact the metallicon electrode or the external lead terminal. The thickness is 0.3 mm to 10 mm, preferably about 1 mm to 5 mm for a resin-based material, and 0.2 mm to 5 mm, preferably about 0.3 to 3 mm for a metal-based material. Getting worse. If it is thick, the heat dissipation / cooling performance or small size / lightness of the capacitor element will deteriorate.
Moreover, in order to improve heat dissipation and cooling performance, an uneven surface may be provided on the external surface, or a material with good heat dissipation may be provided on the external surface. As a material with good heat dissipation, a radiation type is preferable to a conduction type.
The capacitor element to be accommodated is accommodated so that both ends provided with the extraction electrodes are open ends of the cylindrical case. The gap between the cylindrical case and the capacitor element after the housing is preferably as narrow as possible in terms of heat transfer.

The concave terminal cover described in the present invention covers both ends so that the end portion of the cylindrical case containing the capacitor elements is hidden. The cylindrical cases each containing a plurality of capacitor elements are arranged in parallel, Connect in parallel at the lead-out terminals and cover both ends so that both ends of the cylindrical case are hidden together.
Materials include resin molded products such as PET (polyethylene terephthalate), PPS (polyphenylene sulfide), PPE (polyphenylene ether), PBT (polybutylene terephthalate), POM (polyoxymethylene), PPO (polyphenyl oxide), or polychlorinated. Vacuum resin molded products such as vinyl and polycarbonate, such as aluminum, iron and stainless steel, or a laminate of resin and metal. You don't have to worry about this. Moreover, you may reinforce with fillers, such as glass fiber. In the case of a laminate of a resin and a metal or a metal, it is necessary to have a structure in which the metal portion does not contact the metallicon electrode or the external lead terminal.

The external lead terminal described in the present invention is connected to the metallicon electrode of the capacitor element at one end and connected to the outside of the capacitor at the other end, and can be deformed such as a metal foil, thin plate, or wire, solder connection, welding Anything that can be pressed can be used without limitation.
In the case of a thin plate, compared to a linear lead wire that can be bent in any direction, a foil-like metal plate is easy to bend in the thickness direction, but is difficult to deform in the width direction, and the position of the bent upper body is fixed. Therefore, the connection terminals do not fluctuate and the connection terminals having different potentials do not cross each other. Moreover, the allowable current value itself is higher for the foil-shaped terminal than for the lead wire terminal. Further, unlike a lead wire having a round cross section, the thickness of a foil-like metal plate is small, so that the thickness of a soldered portion can be reduced, which is advantageous for downsizing of a capacitor.

The insulating resin described in the present invention is an insulating resin for filling the inner side of the concave terminal cover or the inner side of the cylindrical case, and examples thereof include insulating epoxy, urethane, and silicon resin. Good. Moreover, what mixed the filler etc. in the said resin is also preferable. As the filler, hydroxides such as silicon, titanium, aluminum, calcium, zirconium, and magnesium, oxides, carbides, nitrides, and composites thereof can be used. If necessary, a flame retardant and an antioxidant may be added. In particular, it is preferable that the heat dissipation is large.
The filling condition of the insulating resin includes the method of filling the inside of the concave terminal cover and the gap portion in the cylindrical case up to the filling surface as much as the filling surface of the concave terminal cover with the insulating resin, For example, a method of filling the gap in the cylindrical case with an insulating resin can be used.
In any case, it is filled with an insulating resin so as to fill at least a gap between the cylindrical case and the concave terminal cover. Accordingly, it is preferable that the metallicon electrode part and the external lead terminal part in the vicinity thereof are covered with an insulating resin.

The cylindrical case is fixed by fixing the concave terminal cover with a convex portion along the outer circumference of the cylindrical case, or by attaching a concave groove along the outer dimension of the cylindrical case. Means are mentioned.
Even if the cylindrical case does not directly contact the concave terminal cover, the cylindrical case and the capacitor element accommodated therein are fixed by filling the cylindrical case with an insulating resin inside or in addition to the concave terminal cover. be able to. Moreover, when a collar is provided on the outer side surface of the end of the cylindrical case, it becomes a wedge shape, and the cylindrical case can be more strongly fixed to the insulating resin filled. Moreover, since the thickness of the cylindrical case is increased by the flange portion, it is possible to fix the screw from the concave terminal cover side.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a longitudinal sectional view of a capacitor showing an embodiment of the present invention.
In FIG. 1, three capacitor elements 2 each having a metallicon electrode 1 provided at both ends are arranged in parallel, and each capacitor element 2 has a cylindrical case 3 having both ends open, and the metallicon electrode 1 is opened. Each is accommodated so as to be exposed at both ends.
Further, the metallicon electrodes 1 are connected in parallel by the external lead terminals 4 separately on the upper and lower sides.
The external lead terminal 4 is connected between the capacitor elements 2 by notches 5 provided on both side surfaces of the cylindrical case 3 so that the q between the capacitor elements 2 can be easily connected and the metallicon electrode 1 can be easily connected. It is connected.
The upper and lower open ends of the cylindrical case 3 are collectively covered with a pair of concave terminal covers 6 so that the concave side faces inward, and the inner side of the concave terminal cover 6 is filled with an insulating resin 7. .
In FIG. 1A, the filling range of the concave terminal cover 6 is such that the inside of the concave terminal cover 6 and the gap in the cylindrical case 3 up to the filling surface as much as the filling surface inside the concave terminal cover 6 are filled. In FIG. 1 (b), the inside of the concave terminal cover 6 and the gap in the cylindrical case 3 are filled. The inside of the cylindrical case 3 is filled with the insulating resin 7 by the notches 5 provided on both side surfaces of the cylindrical case 3, and is cured and solidified by heating or the like.

FIG. 2 is a cross-sectional view in the longitudinal direction of the capacitor showing the embodiment of the present invention.
The difference from FIG. 1 is that a column 8 is additionally provided between the concave terminal covers 6 in the components shown in FIG.
The support column 8 is provided between the capacitor elements 2 or around the capacitor. In addition, it is preferable in terms of fixing that the support column 8 is screwed with a screw 9 or the like from the concave terminal cover 6 side. The support 8 can help to temporarily fix the shape of the capacitor until the liquid insulating resin 7 is solidified. Further, after the liquid insulating resin 7 is solidified, the shape of the capacitor can be useful for maintaining the strength. However, if the support column 8 is increased more than necessary, the shape of the capacitor is increased correspondingly, and the gap between the cylindrical cases 3 is narrowed, which is not preferable in terms of heat dissipation.

FIG. 3 is a cross-sectional view in the width direction of the capacitor showing the embodiment of the present invention. FIG. 3 shows a cross-sectional view perpendicular to the direction of FIG. FIG. 3A shows a method of fitting into a concave groove, FIG. 3B shows a method of fitting into a convex portion, and FIG. 3C shows a method of providing a raised bottom. Insulating resin to be filled is omitted.
3A, the concave terminal cover 6 is provided with the concave groove 10 and the cylindrical case 3 is fitted, and the part to be fitted may be a part of the whole circumference or a part thereof. Partially, it is easier to obtain the strength of the concave terminal cover 6.
In the method of fitting in FIG. 3B, the convex portion 11 is provided in close contact with the concave terminal cover 6 along the outer periphery of the dimension of the cylindrical case 3. The convex part 11 may be partial in addition to the entire circumference.
3A or 3B, when the end portion of the cylindrical case 3 contacts the concave terminal cover 6, both side surfaces of the cylindrical case 3 are arranged so that the external lead terminal 4 can be easily routed. It is preferable to provide a space such as a notch through which the external lead-out terminal 4 passes.
3 (c) is the same as the method shown in FIG. 3 (b), in which the cylindrical case 3 is provided with a raised bottom portion 12 so that the end of the cylindrical case 3 contacts the raised bottom portion 12. It is preferable that there is no need to provide a space such as a notch through which the external lead terminal 4 passes on both side surfaces of the cylindrical case 3.

FIG. 4 shows an example of the manufacturing method of the present invention.
First, as shown in FIG. 4A, three capacitor elements 2 provided with metallicon electrodes 1 at both ends are arranged side by side in parallel.
Next, as shown in FIG. 4B, each capacitor element 2 is accommodated in a cylindrical case 3 having both ends opened so that the metallicon electrode 1 is exposed at both the opened ends. Next, the metallicon electrodes 1 are connected in parallel by the external lead terminals 4 separately on the upper and lower sides.
Next, as shown in FIG. 4C, the lower open end of the cylindrical case 3 is collectively covered with the concave terminal cover 6a so that the concave side faces inward. Next, the inside of the concave terminal cover 6a is filled with an insulating resin, and the insulating resin is cured. Next, it is rotated 180 degrees so that the concave terminal cover 6a is on the upper side.
Next, as shown in FIG. 4 (d), the lower open end of the cylindrical case 3 is collectively covered with the concave terminal cover 6b so that the concave side faces inward. Next, the inside of the concave terminal cover 6b is filled with an insulating resin, and the insulating resin is cured.

A capacitor having a rated voltage of 1100 V and a capacitance of 1600 μF was produced.
The capacitor element has a diameter of a single-sided metallized film with a metal-deposited electrode on the surface of a 5 μm thick polypropylene film dielectric film and a similar metallized film that are stacked in layers so that the metal surfaces do not overlap. Was wound to be 100.5 mm, and 0.6 mm thick metallicon electrodes were formed by thermal spraying of zinc metal on both ends of the wound.
Next, three capacitor elements of the same shape were arranged side by side in parallel, and each capacitor element was placed in a cylindrical case made of polyphenyl oxide having an inner diameter of 102 mm and a thickness of 2 mm with both ends open, and at both ends with the metallicon electrodes open. Each was accommodated so as to be exposed. Next, the metallicon electrodes were connected in parallel by external lead terminals that were tin-plated on a copper foil having a thickness of 200 μm and a width of 29 mm separately on the upper and lower sides. Next, the lower open end of the cylindrical case is collectively covered with a concave terminal cover made of polyphenylene ether having a thickness of 3.5 mm and a depth of 21.5 mm so that the concave side faces inward. Next, the inside of the concave terminal cover is filled with an insulating urethane resin, and the resin is thermoset. Next, it is rotated 180 degrees so that the concave terminal cover is on the upper side. Next, the lower open end of the cylindrical case 3 is collectively covered with a concave terminal cover so that the concave side faces inward. Next, the inside of the concave terminal cover is filled with an insulating urethane resin, and the resin is thermoset. In filling the insulating resin, vacuum defoaming and vacuum injection treatment were performed.

  The inside of the concave terminal cover was filled with an insulating urethane resin, and after curing the resin, the cylindrical case was fully filled with the same insulating urethane resin and cured in the same manner as in Example 1 except that the resin was cured. .

  DESCRIPTION OF SYMBOLS 1 ... Metallicon electrode, 2 ... Capacitor element, 3 ... Cylindrical case, 4 ... External lead-out terminal, 5 ... Notch part, 6, 6a, 6b ... Concave terminal cover, 7 ... Insulating resin, 8 ... Support | pillar, 9 ... Screw, 10 ... concave groove, 11 ... convex part, 12 ... raised bottom part

Claims (3)

  A plurality of capacitor elements having metallicon electrodes at both ends are accommodated in a cylindrical case with both ends open, arranged in parallel, connected in parallel with an external lead terminal, and both end portions of the cylindrical case are collectively A film capacitor that is covered with a pair of concave terminal covers and covered with an insulating resin inside the concave terminal cover.   A plurality of capacitor elements having metallicon electrodes at both ends are respectively accommodated in a cylindrical case opened at both ends, arranged in parallel, connected in parallel by an external lead terminal, and both end portions of the cylindrical case are collectively covered Thus, a film capacitor in which a pair of concave terminal covers is covered and the inside of the concave terminal cover and the inside of the cylindrical case are filled with an insulating resin.   3. The film capacitor according to claim 1, further comprising fixing means provided on the concave terminal cover for fixing the cylindrical case to the concave terminal cover.

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