JPS5940519A - Metallized film condenser - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a metallized film capacitor in which a double-sided metallized film and a dielectric film are laminated and wound, and metallicon is applied to the end faces of the wound film. A metallized film capacitor in which a large dielectric film is used to bond a metallized film and a dielectric film, and this dielectric film is interposed in the margin between an electrode and a metallicon to increase the corona discharge starting voltage. Regarding.

Conventionally, a metallized film capacitor 1 has been manufactured by leaving a margin part 2 on a dielectric film 3 (7) and depositing gold (4*t) on a dielectric film (B1); The film 5 is laminated and wound to form a metallized film capacitor element, and as shown in FIG. Usually, the width of the dielectric film 3 is d4 to 16wm, and the width of the margin part 2 is 1l-t1.
f; set at 2.5 W, the electrode 4 is made of aluminum, zinc, etc., and its thickness is 0.02 to 0.1
It is said that m. Therefore, even if the wound element is heated and pressed by a flat hot plate, the elements shown in FIG. 6, which is a partial sectional view of FIG. 2, and FIG. 4, which is a partially enlarged view of FIG. As shown, a gap 9 corresponding to the thickness of the electrode 4 is formed in the margin part 2, and fine metallicon material particles enter into the gap 9, so that the distance between the electrode 4 and the metallicon 7 is extremely short. Moreover, the surface of the metallicon 7 becomes uneven and has sharp edges,
The electric field is concentrated there, and a state is reached where corona discharge can occur between the metallicon 7 and the electrode 4 at an extremely low voltage. or,
Since it is too early to completely remove the air layer 8 between the metallized films 5 even with the above-mentioned heating and pressure pressing, the opposing electric current f! ! Even during the 4th period, corona discharge occurs [7]. Therefore, conventional metallized film capacitors have a withstand voltage that is extremely lower than that of the dielectric film due to corona discharge, and the dielectric film deteriorates, resulting in a short lifespan. -1 was low.

In order to solve the above-mentioned problems, various methods have been tried in the past, such as increasing the thickness of the metallic particles, decreasing the thickness of the evaporated electrode, or increasing the width of the margin. A method for setting the corona discharge starting voltage has been introduced as a measure to prevent the corona discharge starting voltage from dropping due to metallic contacts. However, since metallicon is formed by spraying molten metal, it is difficult to control the particle size, and if the long rod is made thinner, the contact area with the metallicon will be smaller. There is a problem that the induced pressure welding deteriorates due to repeated charging and discharging, and the method of carefully increasing the margin width is a simple and effective method (σ, but it increases the amount of usage and the shape There is a problem that the price increases when the thickness is measured.Furthermore, the above method has the problem that the corona norelectron initiation voltage decreases due to the air layer between the metallized films.
Fi doesn't know how to deal with equality.

Therefore, as a countermeasure against both the air layer between the metallized film and the metallized film, a method has been adopted in which the gap in the margin part and the air layer between the metallized film are removed by impregnating the metallized film with an impregnating agent such as impregnating oil or wax. ing. However, although this method can achieve satisfactory effects in terms of performance, it complicates sealing into the case and has problems in terms of workability.The present invention solves the above-mentioned problems. The purpose of this invention is to provide a metallized film capacitor that increases the corona discharge starting voltage and has a long life and high reliability without the need for a complicated structure or complicated work.

In order to achieve the above object, the metallized film capacitor of the present invention is a metallized film formed by coating electrodes on both sides of a first four-layer dielectric film except for at least the side portions (C formed margin portions). and a second dielectric film having a higher thermal contraction rate than the first dielectric film are wound in close contact with each other, and a metallicon is applied to the wound end face, and a margin portion between the electrode and the metallicon is formed. The structure is characterized in that the second dielectric film is interposed therebetween.An embodiment of the present invention will be described below with reference to the drawings.

5 to 8 show a metallized film capacitor according to an embodiment of the present invention. FIGS. 1 and 5 are schematic perspective views during winding, and FIG. 6 is a partial Hdt side view after winding. Figure 7 is a partial cross-sectional view after heating, and Figure 8 is a partial enlarged cross-sectional view after being coated with metallicon. , 4 electrodes 5 is a metallized film, 6 is a mackerel, 2 is a dielectric film, and 7 is a metallicon. As shown in FIG. 5, one surface of the polyester film 6 as shown in FIG.
A margin part (non-'fhj chair attachment part) 2 with a width of 1 to 2.5 m is formed in the ll + 1 h" part of -4, and one electrode 4f is deposited 17 by vapor deposition or other means, and then a polyester film is applied. On the other side of 6, the other side edge has a shape h of 1 to 25 fin width.
A double-sided metallized film 5 formed by adhering the other electrode 4' except for the rounded margin part 2' is a second film having a width of 0.5 to 2.5 wa narrower than that of the polyester film 3. Polypropylene film as a dielectric film6
A metallized film capacitor element is formed by laminating and winding the metallized film 5 and the polypropylene film 6. In this state, as shown in FIG. is formed. However, the heat shrinkage rate of the polypropylene film 6 is higher than that of the polyester film 6, and the odor is about 5 times that of the polyester film 2 at 100 to 150°C.
When the rolled metallized film capacitor element is heated at 100 to 150°C for several minutes under pressure with a press plate, the polypropylene film 6 shrinks greatly in its width direction, and as shown in FIG. conversion film 5
f close contact to eliminate the air layer 8, and furthermore, the margin part 2.2
Therefore, the 8th
As shown in the figure, a metallicon 7 is attached to the end surface of the winding of the metallized film capacitor element.

However, the margin part 2 between the electrode 4 and the metallicon 7 (L-
11171d, since the polypropylene film 6 is interposed, the entry path for the metallicon material is completely closed.

The other metalized film capacitors related to the current flow side of the present invention shown in FIGS. 9 to 11 have a series electrode structure, and claw 9 is a schematic perspective view in the middle of winding,
FIG. 0 is a partial cross-sectional view after winding, and FIG. 11 is a partial cross-sectional view after heating and applying metallicon. In the figure, the metallized film capacitor 1 has tI'I, - as shown in FIG.
On one side of the polyester film 3 as a dielectric film, a shape of hyt and a width of 1 to 2.5 nm is formed on both side edges.
Leaving the margin part (non-electrode adhered part) 2, 2',
↑li, ' 4if < 4 is deposited by means of vapor deposition or the like, and then a non-electrode deposited part 10 is formed on the other surface of the polyester film 6 at a portion corresponding to approximately the center of the one electrode 4. A double-sided metallized film 5 with a series structure formed by forming and depositing the other electrodes 4/a, 4/l) and 0.5 to 2.5 +w than the polyester film 3 mentioned above.
A polypropylene film 6 as a narrow second dielectric film is laminated and wound to form a metallized film capacitor element. In this state, as shown in FIG. 10, an air layer 8 is interposed between the metallized film 5 and the polypropylene film 6 -! Also in the margin parts 2, 2' of the metal film 5, gaps 9, 9' corresponding to the thickness of the box and pole 4 are formed, respectively. However,
If the metallized film capacitor element in this state is heated at 100 to 150°C for several minutes under pressure with a press plate, it will have a heat shrinkage rate of about 5 times or more than that of polyester film 3K in the above temperature range. The polypropylene film 6 shrinks greatly in its width direction, comes into close contact with the metallized film 5, eliminates the air layer 8, and further fills the gaps 9,9' in the margin parts 2, 2'. Therefore, as shown in FIG. 11, even if the metallicon 7 is applied to the wound end face of the metallized film capacitor element, the margin part 2 between the electrode 4 and the metallicon 7, with the 2'Fld polypropylene film 6 interposed, L9; (7) j゛, the entrance path of the metallicon material is completely closed. In general, capacitors with series capacitor) rlp structure are
Since the series connection of a plurality of capacitors is sharp, the applied voltage is divided and applied to each capacitor, so it is possible to obtain an arbitrary capacitor with high resistance as a whole. By adopting this configuration, the effect is further increased.

In the embodiment of the present invention described above, G1. - and the first frost-inducing, body film 1. Although the case where polyester film and polypropylene film are used respectively is shown, the material of the dielectric film is not limited to these. Examples include polycarbonate, polyethylene, polyethylene terephthalate, polyisoamide, polystyrene, Teflon, etc. , it is possible to appropriately select and use the second dielectric film in combination so that the heat shrinkage rate of the second dielectric film is greater than that of the first dielectric film, and in that case, I
For /r, the heating conditions (temperature, time, etc.) may be set depending on the material, thickness, etc. of the selected dielectric film.

FIG. 12 is a graph showing the corona discharge starting voltage of a conventional metallized film capacitor and a metallized film capacitor of the present invention. The corona discharge starting voltage of the present invention (II)
is the corona discharge starting voltage of the embodiment shown in FIGS. 9 to 11.

The same sample had a width of the first dielectric film of 20 mm and a thickness of 4 mm, a width of the second dielectric film of 19 mm,
The thickness is 41! m1 A metallized film capacitor with a margin width of 1.5 m was used.

As is clear from the graphs, compared to the conventional one, the embodiments shown in FIGS. 5 to 8 are approximately 1.6 times as large, and the embodiments shown in FIGS. 2 to 11 are approximately 2.9 times as large. The corona discharge starting voltage was , and the effect of the present invention was demonstrated.

As described above, the metallized film capacitor of the present invention is produced by laminating and winding a double-sided metallized film on which a bougin portion is formed and a dielectric film having a higher thermal shrinkage coefficient than a kneaded film, and applying a coating to the end surface of the wound film. Since the dielectric film is interposed in the margin between the metallized metal capacitor and the electrode, it has a complex structure like a metallized film capacitor impregnated with an impregnating agent, and is also complicated. Since the air layer between the whole and one-component films and the voids in the margins are removed without any additional work, a high corona discharge start rate can be achieved.

Therefore, the metallized film capacitor of the present invention can prevent a decrease in withstand voltage caused by corona discharge and deterioration of the dielectric film, and has a high withstand voltage, long life, and high reliability, even under severe usage conditions. This kit can be effectively adapted to AC high voltage capacitors, etc.

[Brief explanation of drawings]

Figures 1 to 4 show conventional metallized film capacitors, Figure 1 is a schematic perspective view of the capacitor in the middle of winding, Figure 2 is a perspective view of the metallized film capacitor coated with metallicon. 5 to 8 show a metallized film capacitor according to an embodiment of the present invention, and FIG. 5 is a partially enlarged view of FIG. Schematic perspective view during rotation, No. 6
Figure 7 is a partial cross-sectional view after winding, Figure 7 is a partial cross-sectional view after hot pressing, Figure 8 is a partial enlarged cross-sectional view after applying metallicon,
9 to 11 show metallized film capacitors according to other embodiments of the present invention, in which FIG. 9 is a schematic perspective view during winding, FIG. 10 is a partial sectional view after winding, and FIG. The figure is a partial cross-sectional view of a metallized capacitor, and FIG. 12 is a graph showing the corona discharge starting voltage of a conventional metallized film capacitor and a metallized film capacitor of the present invention. 1...Metalized film capacitor 2, 2'...
Machine part 3...first dielectric film 4,
4', 4'a, 4/b... Electrode 5... Metallized film 6... Second dielectric film 7
... Metallicon patent applicant Okaya Electric Industry Co., Ltd.

Claims (3)

[Claims] (1) A metallized film formed by coating electrodes on both sides of a first dielectric film except for margins formed at least on the side edges, and a metallized film having a higher heat shrinkage rate than the first dielectric film. A second dielectric film having the electrode and a second dielectric film are laminated and wound in close contact with each other, and a metallicon is applied to the end face of the winding, and the second dielectric film is interposed in a margin between the electrode and the metallicon. metallized film capacitor. (2) The metallized film capacitor according to claim 1, wherein the electrodes have a series structure. (3) The metallized film capacitor according to claim 1 or 2, wherein the first dielectric film is a polyester film, and the second dielectric film is a polypropylene film.