JP5653242B2 - Film capacitor - Google Patents

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 formed by depositing aluminum or zinc on a dielectric film such as PP (polypropylene), PET (polyethylene terephthalate) or PS (polystyrene) to form an electrode, and laminating or winding this to form a capacitor element. Or the aluminum foil electrode was laminated | stacked or wound with the film, and the capacitor | condenser element was comprised. 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 insulating resin was poured into the container, and the insulating resin was filled in the capacitor element and the lead wire portion.
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

In order to manufacture a large-capacity capacitor having a plurality of capacitor elements in a small size and a light weight, an insulating adhesive resin tape is wound around the outer periphery of the side surface of the capacitor element as in Patent Document 1, or a heat shrink resin tube is provided. With this structure, the capacitor element expands and contracts depending on the environment used at a high temperature and a low temperature, and the adhesive resin tape is displaced to reduce the adhesive force. Therefore, the moisture resistance tends to be reduced. 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, instead of using a structure in which an insulating adhesive resin tape is wound around the outer periphery of the capacitor element or a heat-shrinkable resin tube is provided, a plurality of capacitor elements provided with metallicon electrodes at both ends are opened at both ends. Each is accommodated in a cylindrical case, arranged in parallel, connected in parallel with an external lead terminal, covered with a pair of concave terminal covers so that both end portions of the cylindrical case are covered together, the inside of the concave terminal cover or A method of filling the inside of the cylindrical case with an insulating resin is conceivable. In this case, since there is a space between the capacitor element, the cylindrical case, and the inside of the concave terminal cover, it is difficult to inject the insulating resin into this space due to this lid structure.
Therefore, when providing a large-capacity capacitor having a plurality of capacitor elements in a small and light weight, it is an object to improve the lid structure and provide a film capacitor excellent in moisture resistance, insulation resistance and strength.

In order to solve the above problems, the present invention provides the following film capacitor.
(1) A plurality of capacitor elements provided with metallicon electrodes on both ends, a cylindrical case with both ends accommodating the capacitor elements, and a cylindrical case accommodating the capacitor elements are arranged in parallel, and they are arranged in parallel. A connected external lead terminal, a pair of concave terminal covers that are covered so that both end portions of the cylindrical case collectively cover, an insulating resin filled inside the cylindrical terminal cover or inside the cylindrical case, A film capacitor having a notch or a through hole filled with the insulating resin on at least one side of the side surface of the end of the cylindrical case.
(2) The film capacitor according to claim 1, wherein the notch or the through hole has an opening narrower toward a center side in a length direction of the cylindrical case.

  According to the structure of the present invention, when a large-capacity capacitor having a plurality of capacitor elements is provided in a small size and light weight, a film capacitor excellent in moisture resistance, insulation resistance and strength can be provided.

The cross section of the width direction of the capacitor | condenser which shows embodiment of this invention, and the perspective view of the cylindrical case are shown. The other cylindrical case of the capacitor | condenser which shows embodiment of this invention is shown. The example of the manufacturing method of this invention is shown.

In the capacitor element described in the present invention, a set of metallized films in which a metal vapor deposition electrode is provided on the surface of a dielectric film such as PP (polypropylene), PET (polyethylene terephthalate), PS (polystyrene), etc., the metal surfaces do not overlap. In this way, two metal sheets are alternately stacked and wound, and metallized electrodes are formed on the wound ends 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 metallicon 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 whose both ends are open, accommodates a capacitor element therein, and protects it in terms of weather resistance and strength. At least on the end side surface of the cylindrical case, One side is provided with a notch or a through hole filled with the insulating resin shown below.
Further, the capacitor element to be accommodated is accommodated such that both ends provided with the metallicon 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.

As the material of the cylindrical case, resin molded products such as PET (polyethylene terephthalate), PPS (polyphenylene sulfide), PPE (polyphenylene ether), PBT (polybutylene terephthalate), POM (polyoxymethylene), PPO (polyphenyl oxide), etc. Or a vacuum resin molded product such as polyvinyl chloride or polycarbonate, a metal such as aluminum, iron or stainless steel, or a laminate 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 resin 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.

Moreover, the notch part or through-hole provided in the cylindrical case is a means for passing the insulating resin shown below, and is provided on the side surface of the end part of the cylindrical case. The shape is formed of a notch or a through hole, and is hidden by an insulating resin filling the inside of the concave terminal cover shown below. By doing so, the insulating resin is also filled in the insulating resin inlet. It is preferable that the number of notches or through-holes is so large that the strength of the cylindrical case does not decrease, because the insulating resin easily enters the cylindrical case.
The width of the notch or the diameter of the through hole is increased or decreased according to the diameter of the cylindrical case, which is about 1 mm to 20 mm.
Moreover, it is preferable that the shape of the notch or the through hole has a narrow opening toward the center in the length direction of the cylindrical case. By doing so, when filling the inside of the concave terminal cover with insulating resin, the filling speed can be increased at the beginning of the gap in the cylindrical case, and the front end toward the center side in the length direction of the cylindrical case Therefore, after filling with insulating resin, it is easy to block moisture entering from the filling surface in a high humidity environment.

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-shaped metal plate is easy to bend in the thickness direction, but is difficult to deform in the width direction, and it is easy to fix the position in a bent state. Therefore, the external lead terminal does not fluctuate and the external lead 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 fills the inside of the concave terminal cover or the inside of the cylindrical case. When filling the inside of the concave terminal cover, it also includes a gap portion in the cylindrical case up to the same filling surface as the filling surface inside the concave terminal cover. Moreover, when filling the inside of a cylindrical case, the case where all the space | gap parts in the cylindrical case are filled with an insulating resin is also included.
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 shows a cross-sectional view in the width direction of a capacitor showing an embodiment of the present invention and a perspective view of its cylindrical case. The left figure shows a sectional view of the capacitor, and the right figure shows a perspective view in which the cylindrical case of the capacitor is extracted and rotated 90 degrees in the length axis direction. 1A shows a case where a notch 8 is provided at the end of the cylindrical case 3, and FIG. 1B shows a case where a through hole 9 is provided at the end of the cylindrical case 3.
In FIG. 1, a capacitor element 2 provided with metallicon electrodes 1 at both ends is accommodated in a cylindrical case 3 having both ends opened so that the metallicon electrodes 1 are exposed at both opened ends.
In addition, the metallicon electrode 1 is connected to the upper and lower terminals by external lead terminals 4 separately.
The external lead terminal 4 is provided with a dent 5 on the side surface of the end of the cylindrical case 3 so that it can be easily led out from the cylindrical case.
Although not shown in FIG. 1, a set of capacitor elements and a cylindrical case are arranged in parallel on the back side and the front side in the same manner, and are connected to the upper and lower sides separately by the external lead terminals 4. It has been.
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. 1, the filling portion of the insulating resin 7 inside the cylindrical case is the gap inside the cylindrical case 3 from the inner side of the concave terminal cover 6 to the same filling surface as the inner filling surface of the concave terminal cover 6. However, it is preferable in terms of moisture resistance and strength to fill all the gaps between the capacitor element in the cylindrical case 3 and the cylindrical case 3.
Further, in FIG. 1A, a notch 8 is provided at the lower end of the cylindrical case 3, and in FIG. 1B, a through hole 9 is provided at the lower end side of the cylindrical case 3. . The insulating resin 7 is easily filled into the cylindrical case 3 by the notch 8 or the through hole 9.

  In addition, since one side of the cylindrical case is opened on the side of the concave terminal cover 6a that is filled with the resin first, it is not always necessary to provide a notch or a through hole in the structure of the cylindrical case. However, if the concave terminal cover 6a side is thermoset by resin filling and then inverted 180 degrees, and the other concave terminal cover 6b is covered with the cylindrical case, the inside of the cylindrical case will be sealed. In addition, replacement of internal air and insulating resin is not easy. In that case, the notch or the through hole provided in the cylindrical case plays a role as an exhaust path in the sealed space and an insulating resin injection path. Therefore, vacuum injection is preferable on the concave terminal cover 6b side to be filled with resin later.

FIG. 2 shows another cylindrical case of the capacitor showing the embodiment of the present invention. FIG. 2A shows a cylindrical case 3 provided with a cutout portion 3 having a triangular cross section, and FIG. 2B shows a cylindrical case 3 provided with a through hole 9 in which a circle having a different diameter is doubled. When the cutout portion 8 is a rectangular parallelepiped as in the case of FIG. 1A, the cutting process is performed by a mold. However, as in the case of FIG. Also, the through hole 9 can be drilled and can easily cope with dimensional changes.
In both cases, the notch 8 or the through hole 9 provided at the end of the cylindrical case 3 has a narrow opening toward the center in the length direction of the cylindrical case.
With this structure, since the opening of the insulating resin is widened toward the end of the cylindrical case in the length direction, the initial filling speed is high in the gap in the cylindrical case, and the length of the cylindrical case is increased. Since the front opening is narrowed toward the center, it is easy to block moisture entering from the filling surface in a high humidity environment after filling with the insulating resin.

FIG. 3 shows an example of the manufacturing method of the present invention.
First, as shown in FIG. 3 (a), three capacitor elements 2 provided with the metallicon electrodes 1 at both ends are arranged in parallel in the horizontal direction.
Next, as shown in FIG.3 (b), the notch parts 8a and 8b are each provided in the both ends of the cylindrical case 3 with which both ends were open | released. Next, each capacitor element 2 is accommodated in the cylindrical case 3 so that the metallicon electrode 1 is exposed at both open ends. Next, the metallicon electrodes 1 are connected in parallel by the external lead terminals 4a and 4b separately on the top and bottom.
Next, as shown in FIG. 3C, 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 so that the notch 8a is hidden, 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. 3D, 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 so that the notch 8b is hidden, 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, a cylindrical case made of polyphenyl oxide having an inner diameter of 102 mm and a thickness of 2 mm, which is open at both ends, is prepared, and notches are formed at four ends of each end, and a cross section with a base width of 10 mm and a height of 10 mm is processed into a triangle. To do.
Next, three capacitor elements having the same shape were arranged side by side in parallel, and each capacitor element was accommodated in the cylindrical case so that the metallicon electrodes were exposed at both open ends. 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 was filled with an insulating urethane resin so that the notch was hidden, and the resin was 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 so that the notch is hidden, 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, 4a, 4b ... External lead-out terminal, 5 ... Recessed part, 6, 6a, 6b ... Concave terminal cover, 7 ... Insulating resin, 8, 8a, 8b ... Notch, 9 ... Through hole

Claims (2)

  A plurality of capacitor elements provided with metallicon electrodes at both ends, a cylindrical case with both ends accommodating the capacitor elements, and a cylindrical case accommodating the capacitor elements are arranged in parallel, and externally connected in parallel. A film having a lead terminal, a pair of concave terminal covers covered so that both end portions of the cylindrical case collectively cover, and an insulating resin filled inside the cylindrical terminal cover or inside the cylindrical case A film capacitor in which a notch or a through hole filled with the insulating resin is provided on at least one side of an end portion side surface of the cylindrical case.   2. The film capacitor according to claim 1, wherein the notch or the through hole has an opening narrowed toward a center side in a length direction of the cylindrical case.

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