JP2011071179A - Metallized film capacitor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To eliminate trouble occurring in an external terminal part of a metallized film capacitor housed in a case and to stabilize moisture resistance, vibration resistance and the like over a long time in a use condition in a wide temperature range, in a metallized film capacitor including a capacitive element equipped with metallicon electrodes at both ends using a metallized film, a bottomed tubular case having an opening on an upper end face for storing the capacitive element, a sealing body sealing the opening of the case having outer and inner surfaces, a pair of external terminals arranged penetrating from the outer surface to the inner surface of the sealing body, and extraction tabs each connecting the external terminal to the metallicon electrode. <P>SOLUTION: In this metallized film capacitor, on the sealing body fixed to the case, a through-hole penetrating from the outer surface to the inner surface is formed; an insulation resin is injected into the case from the through-hole; and a dam-shaped body for stemming the resin running over from the through-hole is arranged on the outer surface of the sealing body. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a metallized film capacitor in which one or more capacitor elements using a metallized film are housed in a case having an opening and sealed with a sealing body.

  In recent years, an inverter circuit suitable for energy saving and high efficiency has been adopted from the consideration of the environment. However, since the working voltage is high, there is a tendency to use a film capacitor among the capacitors. In particular, in applications such as on-vehicle moving bodies, conditions for use such as moisture resistance and vibration resistance are required over a long period of time in a wide temperature range.

  Conventionally, as shown in FIG. 4, a capacitor element using a metallized film is housed in a case 1 having an opening, and a metallized film capacitor filled with an insulating resin 8 is wound with two metallized films stacked. After winding or laminating, winding to draw out the electrode, or spraying a metal such as zinc on the laminated end face and applying the metallicon electrode 3, a temperature treatment called heat treatment is performed as necessary to form the capacitor element 2. To manufacture. Next, the plate-like external lead terminal plate 11 was connected to one or a plurality of electrodes at both ends of the capacitor element 2, housed in the resin case 1, and then filled with the insulating resin 8.

As a technique for improving the durability and weather resistance of a metallized film capacitor using such an external lead terminal plate, Patent Document 1 discloses that an insulating resin to be filled in a case is made of an epoxy insulating resin layer, and the external lead terminal plate A technique is disclosed in which an inorganic filler is added so that the linear expansion coefficient of the uppermost layer from which is derived is minimized. With this technology, the linear expansion coefficient of the uppermost layer of the epoxy insulating resin is made closer to the linear expansion coefficient of the external lead terminal plate, which is a metal, and the thermal followability between the external lead terminal plate and the resin composition is improved. To do. Therefore, a technique for preventing cracks from occurring in the insulating resin of the upper layer is disclosed.
Patent Document 2 discloses a technique in which a molded resin plate is provided in a case filled with an insulating resin instead of the above-mentioned upper layer insulating resin. A technique has been disclosed in which, even if pinholes are generated in the insulating resin during the curing process of the filled insulating resin, the presence of the molded resin plate blocks the outside air and improves the moisture resistance.

JP 2006-147687 A JP 2001-332444 A

  However, the technique of changing the linear expansion coefficient of the resin composition by adding an inorganic filler as described above tends to make the resin composition brittle. Further, the technique of providing a molded resin plate in a case filled with an insulating resin does not mean that the molded resin plate is directly fixed to the case or an external terminal. Therefore, it tends to cause problems in durability and weather resistance due to external stress.

  An object of the present invention is to eliminate problems occurring in the external terminal portion of a metallized film capacitor housed in a case, and to stabilize moisture resistance, vibration resistance, and the like over a long period of time under a wide temperature range of use conditions.

As a means for solving the problems, the present invention provides one or more capacitor elements each using a metallized film and provided with metallicon electrodes at both ends, and a bottomed bottom having an opening on the upper end surface that accommodates the capacitor elements. A cylindrical case, a sealing body having an outer surface and an inner surface that are sealed and fixed to the case, and a space between the inner surface and the outer surface of the sealing body is provided. A metallized film capacitor having a pair of external terminals and a pull-out tab connected between the external terminals and the metallicon electrode, wherein the sealing body has a through-hole penetrating from the outer surface to the inner surface. A metallized film coating in which an insulating resin is injected into the case from the through hole, and a dam-shaped circular body is provided on the outer surface of the sealing body to block the resin protruding from the through hole to the outer surface. It proposes a capacitor.
Further, the present invention proposes a metallized film capacitor in which at least one of the external terminals is provided on the inner side of the circuit body.
Moreover, the metallized film capacitor which provides the said surrounding body in the peripheral part of the outer surface of the said sealing body is proposed.

  ADVANTAGE OF THE INVENTION According to this invention, the metallized film capacitor which eliminates the malfunction which generate | occur | produces in the external terminal part of a metallized film capacitor with a case, and improves a thermal shock, vibration resistance, and moisture resistance on the use conditions of a wide temperature range can be provided. .

1 shows a schematic cross-sectional view and a top schematic view of a metallized film capacitor according to the present invention. FIG. 4 shows a cross-sectional schematic and a top schematic view of another metallized film capacitor according to the present invention. Figure 3 shows a schematic top view of another metallized film capacitor according to the present invention. 1 shows a schematic cross-sectional view of a conventional metalized film capacitor.

  Capacitor element of the present invention, the film surface of polyethylene terephthalate, polypropylene, etc., a metallized film vapor-deposited metal such as aluminum, copper, zinc and the like or rolled or laminated with the metal foil, zinc on both end faces, A metallized electrode is provided by spraying a metal such as copper or aluminum. The cross-sectional shape is circular when it is wound, flat when it is crushed, and quadrilateral when it is stacked, but the side of the flat or square is flat and the storage efficiency and heat dissipation are improved.

  As the metallicon electrode of the present invention, those generally used for film capacitors can be used, which are made of metal or alloy such as copper, zinc, aluminum, tin, solder, etc., and formed by thermal spraying. In some cases, the surface of the electrode may be plated.

  The case of the present invention is a bottomed cylindrical container having an opening on the upper end surface and generally usable for a film capacitor, and is made of plastic or metal. In the case of plastic, for example, it is made of a resin such as polyethylene terephthalate, polybutylene terephthalate, polycarbonate, or polyphenylene sulfide. If it is a metal, it will consist of aluminum, magnesium, iron, stainless steel, copper, etc., for example.

The sealing body of the present invention is a molded body having an outer surface, an inner surface, and a side surface and sealing the opening of the case, and is bonded, fixed or fused to the opening of the case. It is preferable to contact both the opening end surface of the case and the two surfaces of the opening side surface which are in a right angle relationship. In particular, it is preferable to increase the contact area with the inner surface of the opening side surface of the case. Therefore, in order to increase the area of the outer peripheral end surface of the sealing body, it is preferable to provide an overhanging portion on the peripheral portion of the inner surface of the sealing body. In addition, it is preferable to use an adhesive, a sealing agent, or the like for this connection part from the viewpoint of easy manufacture, but it is necessary to at least prevent the insulating resin injected into the case from flowing out from this connection part. is there.
Further, the sealing body is provided with a pair of external terminals provided through the inner surface from the outer surface of the sealing body and a through hole penetrating between the inner surface from the outer surface. An insulating resin is injected into the inside, and a dam-shaped rotating body is provided on the outer surface to block the resin protruding from the through hole to the outer surface.

  The external terminal of the present invention is made of a thick plate, thick wire, and columnar molded body that is difficult to deform, and is preferably a columnar body that is difficult to deform so that it can be connected to the outside by a bolt. For example, the material may be made of a metal or alloy such as copper, aluminum, iron, nickel, stainless steel, phosphor bronze, etc., and tin, solder, etc. may be plated on the surface. It can be used without particular limitation from about 1 mm to about 20 mm in terms of plate thickness.

  In the case of this insulation board with external terminals, the number of parts increases compared to the case of using an external lead terminal board, but the connection between the external connection and the metallicon electrode is connected as a separate part. It can be improved. Moreover, since the freedom of selection of the material and compatibility of the external terminal and the insulating plate is great, the durability and weather resistance of the external terminal and the insulating plate portion can be improved.

  The dam-shaped orbital body of the present invention is provided for clogging resin that is provided on the outer surface of the sealing body and that protrudes from the through hole to the outer surface. The one integrated with the sealing body is preferable, but another part may be used.

The insulating resin of the present invention is an insulating material generally used for filling a film capacitor, and is obtained by mixing a filler or the like with a resin such as an epoxy resin or a urethane resin. 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.
Since this insulating resin is injected into the case from a through hole provided in the sealing body and protrudes to the outer surface from the through hole, a dam-shaped circulating body is provided on the outer surface to block it. When the dam-shaped circulating body is provided around the through hole, the air tightness of the through hole is improved. When the dam-shaped circulating body is provided around the through hole and the external terminal, the airtightness of the through hole and the external terminal is improved. When the dam-shaped circulating body is provided in the peripheral portion of the outer surface of the sealing body, the airtightness between the through hole and the external terminal is improved, and the external terminal and the sealing body are reinforced.

  The drawer tab of the present invention electrically connects the external terminal and the metallicon electrode. A metal foil, thin plate, wire, or the like that can be deformed and that can be soldered, welded, or pressed can be used without limitation. In particular, copper is preferable as a good electrical conductor. In addition, a portion other than the connection portion may be covered with an insulator.

Hereinafter, the present invention will be described based on embodiments shown in the drawings.
FIG. 1 shows a schematic cross-sectional view 1 (a) and a top view schematic view 1 (b) of a metallized film capacitor according to the present invention. FIG. 1 shows a case in which a capacitor element 2 is accommodated in a case 1 having an opening having an open upper end surface, and the opening of the case 1 is sealed by a sealing body 4. A dam-shaped circulating body is provided with a through-hole 7 penetrating the inner surface 4b, injecting the insulating resin 8 into the case 1 from the through-hole 7, and blocking the insulating resin 8 protruding from the through-hole 7 to the outer surface 4a. 9 shows an example of a metallized film capacitor in which 9 is provided on the outer surface 4 a of the sealing body 4.
Reference numeral 1 denotes a case, which is a cylindrical container having an opening at the top, and is made of metal or plastic.
Reference numeral 2 denotes a capacitor element. Two metallized films, that is, two thin strip-like insulating films (usually polyester films) in which aluminum or the like is deposited on one side to form a metal electrode are overlapped and wound a predetermined number of times. The oblong columnar body is flattened, and the metallicon electrodes 3 formed by thermal spraying of metal or alloy are provided on both end faces thereof.
Reference numeral 4 denotes a sealing body, which has an outer surface 4 a and an inner surface 4 b, and is a molded body that seals the opening of the case 1, and is bonded or fixed to the opening of the case 1. An overhang portion 5 is provided on the peripheral portion of the inner surface 4b so as to increase the contact area with the case 1.
Further, the sealing body 4 includes a pair of external terminals 6 provided so as to penetrate from the outer surface 4a of the sealing body 4 to the inner surface 4b, and a through hole 7 penetrating from the outer surface 4a to the inner surface 4b. Is provided. The external terminal 6 has a cylindrical shape and is threaded, and is fixedly connected to the outside by a bolt or the like.
In addition, a dam-shaped circumferential body 9 is provided on the outer surface 4a to inject the insulating resin 8 into the case 1 from the through hole 7 and to block the insulating resin 8 protruding from the through hole 7 to the outer surface 4a. The protruding insulating resin 8 not only fills the through-hole 7 but also reaches the rotating body 9 on the outer surface 4a of the external terminal 6, so that the airtightness of the through-hole 7 is improved. Further, in FIG. 1, since the surrounding body 9 is provided so as to surround the outside of the external terminal 6 and the insulating resin 8 surrounds the external terminal 6, the airtightness between the external terminal 6 and the sealing body 4 is also improved. improves. Further, the amount of the insulating resin 8 only needs to be between the heights of the circulating bodies 9, and may have some variation.
Reference numeral 10 denotes a drawer tab, one end of which is connected to the metallicon electrode 3 and the other end is connected to the external terminal 6.

  The sealing body 4 is a molded body by a dedicated molding machine and can be molded in a state where there is no pinhole or the like penetrating the molded body, and the sealing body 4 and the case 1 are bonded, fixed or melted. Since it is worn, the airtightness and strength between them are improved. Further, the opening ratio of the opening portion of the through-hole 7 having poor airtightness can be made sufficiently small, and the insulating resin 8 to be filled is provided so as to protrude from the opening, so that deterioration of the airtightness can be minimized.

FIG. 2 shows a schematic cross-sectional view 2 (a) and a top schematic view 2 (b) of another metallized film capacitor according to the present invention.
A circumferential body 9 is provided on the outer surface 4a of the sealing body 4 so as to surround three through holes 7 penetrating the outer surface 4a and the inner surface 4b. 3 shows an example of a metallized film capacitor in which the insulating resin 8 that has been injected into and squeezed out is dammed by a rotating body 9. The through hole 7 and the inner surface side of the protruding portion 5 of the inner surface 4b of the sealing body 4 are tapered. As a result, the bubbles of the injected insulating resin 8 are easily discharged to the outside from the through hole 7 smoothly.

FIG. 3 shows a schematic top view of another metallized film capacitor according to the present invention.
On the outer surface 4a of the sealing body 4, the outer periphery of the circulating body 9 is provided at the outermost peripheral portion of the outer surface 4a of the sealing body 4, and three through holes 7 penetrating the outer surface 4a and the inner surface 4b, A metallized film capacitor in which a circulating body 9 is provided so as to surround each of the pair of external terminals 6, an insulating resin 8 is injected into the case 1 from the through hole 7, and the protruding insulating resin 8 is blocked by the circulating body 9. An example is shown. As a result, the sealing body 4 becomes thicker due to the rotating body 9 and the insulating resin 8, so that the airtightness of the through hole 7 and the external terminal 6 is improved, and the sealing body 4 itself is reinforced.

  DESCRIPTION OF SYMBOLS 1 ... Case, 2 ... Capacitor element, 3 ... Metallicon electrode, 4 ... Sealing body, 4a ... Outer surface, 4b ... Inner surface, 5 ... Overhang | projection part, 6 ... External terminal, 7 ... Through-hole, 8 ... Insulating resin, 9 ... Circumferential body, 10 ... Drawer tab, 11 ... External drawer terminal board

Claims (3)

One or more capacitor elements with metallized electrodes on both ends using a metallized film; and
A bottomed cylindrical case with an opening on the upper end surface that houses this capacitor element;
A sealing body having an outer surface and an inner surface, which seals the opening of the case and is fixed to the case;
A pair of external terminals provided through the inner surface from the outer surface of the sealing body;
In the metallized film capacitor having a pull-out tab connected between the external terminal and the metallicon electrode,
The sealing body is provided with a through-hole penetrating from the outer surface to the inner surface, injecting an insulating resin into the case from the through-hole, and damming the resin protruding from the through-hole to the outer surface. A metallized film capacitor provided on the outer surface of the sealing body.   The metallized film capacitor according to claim 1, wherein at least one of the external terminals is provided on the inner side of the circuit body.   The metallized film capacitor according to claim 1, wherein the circulating body is provided in a peripheral portion of an outer surface of the sealing body.

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