JPS5934129Y2 - aluminum electrolytic capacitor - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an aluminum electrolytic capacitor with an improved exterior.

Conventional aluminum electrolytic capacitors are shown in Figures 1 and 2.
As shown in the figure, a sealing rubber stopper 3 was fitted into the opening of a metal case 2 housing a capacitor element 1 to seal it.

Recently, there has been a growing demand for smaller aluminum electrolytic capacitors, and up until now, efforts have been made to improve the surface area magnification of electrode foils, but this approach is already close to its limit.

Under these circumstances, when aluminum electrolytic capacitors are observed, the rubber sealing plug 3 occupies a very large volume of 30 to 40% of the total volume, which is a major obstacle to miniaturization.

Furthermore, since the sealing rubber stopper 3 is made of an organic elastic material such as natural rubber or synthetic rubber, it cannot be cleaned using a halogenated hydrocarbon detergent that is nonflammable and has a large cleaning effect, so trichlorethylene or chlorocene is used. is prohibited.

After the aluminum electrolytic capacitor is installed on a printed circuit board, when cleaning the board, detergent is applied from the contact area A between the sealing rubber stopper 3 and the metal case 2, the insertion area B of the terminal 4, and the surface area C of the sealing rubber stopper 3. permeates, the rubber stopper 3 swells, and the halogen element decomposed and liberated under electric field heating may react with the aluminum electrode foil, reducing the reliability and performance of the capacitor.

Furthermore, the sealing rubber stopper 3 deteriorates and changes in quality in the high temperature range, loses its rebound resilience, and loses its airtight effect.

The hardness changes over time, and the electrolyte vaporizes and scatters, resulting in tan.
δ increases, the capacitance decreases, and the function of the capacitor is lost, and the sealing rubber stopper 3 provided with an explosion-proof valve loses its function due to a change in hardness.

The present invention was developed in view of the above-mentioned circumstances, and by using a metal lid instead of the rubber sealing plug that seals the opening of the metal case and sealing it with the metal lid, it is possible to use a small halogenated hydrocarbon detergent. The object of the present invention is to provide an aluminum electrolytic capacitor that is durable, has a wide range of operating temperatures, is nonflammable, and is inexpensive.

An embodiment of the present invention will be described in detail below with reference to the drawings.

That is, a metal case 1 made of aluminum or its alloy houses a condenser element as shown in FIG. 3A.
A metal lid 12 made of aluminum or an alloy thereof as shown in FIGS. 3B and 3C is fitted into the opening of 1 as shown in FIG. 4, and the end is sealed by seaming 13. be.

In the figure, 14 is a protruding hole for leading out a terminal provided in the metal lid 12, and 15
is a capacitor element, 16 is a terminal, the terminal 16 is led out from the protrusion hole 14, an elastic bushing 17 is inserted into the terminal 16 on the inner periphery of the protrusion hole 14, this is led out from the protrusion hole 14, and the terminal 16 is led out from the protrusion hole 14. While maintaining insulation between the metal cover 12 and the metal lid 12, the outer peripheral wall is caulked and sealed.

The tightening part 13 between the opening of the case 11 and the lid 12 is made of adhesive, paint, or heat-resistant elastic material such as epoxy resin, dinocon rubber, latex, synthetic rubber mainly composed of ethylene-propylene copolymer, polyolefin elastomer, etc. If the seaming is performed with an elastic thin film interposed, the airtight effect will be further improved.

The elastic bushing 17 has a cylindrical portion 18 that is press-fitted into the protrusion hole 14, and the length of the cylindrical portion 18 is approximately 1.5 to 2 times the length of the protrusion hole 14. Form for a long time.

Then, as shown in FIG. 5, the cylindrical portion 18 is bent outward to cover the protruding hole 14 and form a covering portion 19.

By bending the cylindrical part 18 and covering the protruding hole 14 in this way, the capacitor can be attached to the electronic circuit board in a stable state during wiring, and the cylindrical part 1
Vibration can be absorbed at the bent tip of No. 8, and vibration resistance can be improved.

Alternatively, the elastic bushing 17 may cover the entire lower surface of the metal lid 12 and also serve as an elastic thin film of the seaming portion 13, as shown in FIG.

It is also important that the elastic bushing 17 has a thickness that corresponds to the withstand voltage of the capacitor in order to provide insulation between the metal cover 12 and the terminals 16.

Further, by caulking the protruding hole 14 from which the terminal 16 is led out, the airtight effect can be further improved by caulking the outer circumferential wall of the protruding hole 14 at one to two places or several places.

Further, as shown in FIG. 7, a protrusion hole 14 for leading out the terminal may be provided on the bottom surface of the metal case 11, and the metal lid 12 may be sealed with the winding last.

In the above description, the case of an aluminum electrolytic capacitor with terminals in the same direction has been exemplified, but it goes without saying that the present invention can also be applied to an aluminum electrolytic capacitor with terminals in opposite directions.

As detailed above, according to the present invention, a metal lid made of aluminum or an alloy thereof is fitted into the opening of a metal case made of aluminum or an alloy thereof, which houses a capacitor element connected to a terminal. An elastic bushing having a cylindrical part longer than the protrusion hole is inserted into the protrusion hole for protruding the terminal provided on the bottom of the metal cover or the case, and the terminal is led out, and the opening of the metal case and the end of the metal cover are tightened. By sealing the product, it is compact and can withstand the use of halogenated hydrocarbon detergents, and since the exterior is entirely made of metal, the operating temperature range is significantly expanded from -70 to +2
It is possible to provide a nonflammable and inexpensive aluminum electrolytic capacitor that can be used up to 00°C.

[Brief explanation of the drawing]

Figures 1 and 2 are side sectional views showing conventional aluminum electrolytic capacitors, and Figures 3A to 3C show the metal case and metal lid that constitute part of the aluminum electrolytic capacitor of the present invention. FIG. 3A is a side sectional view of the metal case, FIG. 3B is a top view of the metal lid, FIG. 3C is a side sectional view of the metal lid, and FIG. 4 is an aluminum electrolytic capacitor according to an embodiment of the present invention. FIG. 5 is a side sectional view showing the capacitor shown in FIG. 4 in a completed state after bending the cylindrical part, and FIG. 6 is a side sectional view showing an aluminum electrolytic capacitor according to another embodiment of the present invention. 7 is a side sectional view showing an aluminum electrolytic capacitor according to another embodiment of the present invention. 11... Metal case, 12... Metal lid, 13... Sealing part, 14... Protruding hole,
15... Capacitor element, 16... Terminal, 17... Elastic bushing, 18...
・Cylindrical part.

Claims (1)

[Scope of utility model registration request] A capacitor element to which a terminal is connected, a metal case made of aluminum or its alloy that houses the capacitor element, a metal lid made of aluminum or its alloy that fits into an opening of the metal case, and the metal lid or the metal the terminal lead-out protrusion hole provided on the bottom of the case; an elastic bushing having a cylindrical portion longer than the protrusion hole into which the terminal is press-fitted; An aluminum electrolytic capacitor characterized by comprising a covering portion that covers a protruding hole.