JP3344690B2 - Case for capacitor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a case used for a capacitor.

[0002]

2. Description of the Related Art Electrolytic capacitors have excellent features such as being small, capable of obtaining a large capacitance, and being inexpensive. There is a disadvantage that the life is shortened.

As a countermeasure for shortening the service life due to the heat generated inside the capacitor, there has been proposed an electrolytic capacitor which dissipates heat through an aluminum pipe inserted into the center of the capacitor element which is heated to the highest temperature. That is, a capacitor element is wound around an aluminum pipe as a core, and both ends of the aluminum pipe are fitted and sealed in respective holes formed in a terminal plate for sealing a case bottom and a case opening. There is known a configuration in which a case in which a pipe-shaped projection is extended from is used, a wound capacitor element is fitted into the pipe-shaped projection, and a case opening is sealed.

However, in the case of using the former aluminum pipe as the winding core, it is difficult to connect and seal the aluminum pipe to the bottom of the case and the aluminum pipe to the terminal plate, which causes leakage of the driving electrolyte. There were inconveniences such as. In addition, when the latter case using the pipe-shaped projection is used, in the case where the outer diameter of the pipe-shaped projection is 10 mm to 30 mm, the length is limited to about 100 mm, and a sufficient length cannot be secured. There was a disadvantage that heat dissipation was insufficient.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned drawbacks, and by providing a capacitor case in which the length of a pipe-like projection formed on the bottom surface is increased. Improves the heat dissipation characteristics of the capacitor,
The purpose is to obtain a long-life capacitor.

[0006]

In order to achieve the above object, the present invention has a pipe-like projection formed at the center of the bottom of the case toward the case opening direction. The bottom surface has a taper of 3 to 10 degrees.

In the above-described capacitor case, a long pipe-shaped projection can be obtained, so that the heat radiation characteristics of the capacitor can be improved, an allowable ripple current is large, and a long-life electrolytic capacitor or the like can be provided.

If the taper formed toward the pipe-like projection is less than 3 degrees, the required length cannot be obtained because the pipe-like projection does not extend during the manufacture of the case.

If the angle exceeds 10 degrees, the height from the bottom of the case to the base of the pipe-shaped projection increases, so that the length of the capacitor element decreases, the capacitance that can be accommodated decreases, and the case is reduced. There is a problem that an outer peripheral edge of a punch of a die to be manufactured is chipped or broken.

Therefore, in the present invention, the taper formed toward the pipe-shaped projection is set at 3 to 10 degrees.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a case for an electrolytic capacitor according to the present invention will be described with reference to the drawings. FIG. 1 shows a case for an electrolytic capacitor according to the present invention.
Outer diameter 76mm x wall thickness 1.1mm x bottom thickness 1.1mm
(At inner circumference 2), inner diameter 15 mm of pipe-shaped projection 3
The wall thickness was set to 1.2 mm, and the case body 1 and the pipe-shaped protrusions 3 obtained when the case was manufactured (by impact extrusion) were provided on the inner bottom surface of the case body 1 with the respective elongations (length). FIG. 2 shows the relationship with the taper 4.

As is clear from FIG. 2, when the taper 4 is 2 degrees, the elongation of the pipe-shaped projection 3 is different from that when it is 3 degrees or more. The mold may be damaged or cracked, or the center of the pipe-shaped projection 3 may be increased, so that the capacity of the capacitor element that can be accommodated is reduced.

The case 1 manufactured as described above houses the capacitor element 5 as shown in FIG. 3, and the terminal plate 7 to which the external terminal 6 connected to the capacitor element 5 is attached is fitted to the opening edge. And sealed it. The sealing was performed by winding the opening edges of the case body 1 and the pipe-shaped projection 3 respectively.

[0014]

As described above, in the case for an electrolytic capacitor according to the present invention, the taper formed on the inner bottom surface of the case main body is set at 3 to 10 degrees, so that the elongation of the pipe-shaped projection during the production of the case is improved. And a long pipe-shaped projection can be obtained. Therefore, it is possible to provide an electrolytic capacitor having good heat dissipation and a large ripple current.

In the embodiment, the electrolytic capacitor has been described. However, the present invention can be applied to other capacitors such as a film capacitor.

[Brief description of the drawings]

FIG. 1 is a front sectional view showing a capacitor case according to the present invention.

FIG. 2 is a curve diagram showing the relationship between the taper provided on the inner bottom surface of the case and the elongation of the case body and the pipe-shaped projection.

FIG. 3 is a partial sectional view showing a capacitor using the case of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Case main body 2 Inner diameter peripheral part 3 Pipe-shaped protrusion 4 Taper 5 Capacitor element 6 External terminal 7 Terminal plate

Claims (1)

(57) [Claims] 1. A case having a pipe-like projection formed at the center of the case bottom toward the case opening direction, and a bottom surface of the case having a taper of 3 to 10 degrees toward the pipe-like projection. Case for the capacitor.