JP2548358Y2 - Electrolytic capacitor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial application field) The present invention relates to an improvement in an exterior structure of a horizontal electrolytic capacitor.

(Prior Art) Regarding mounting of electronic components on a circuit board, a face bonding type in which electrodes of an electronic component are directly connected to a board has been widespread from a through-hole type in which a lead wire is inserted into a hole in the board.

However, in the case of face bonding type mounting, it is necessary to expose the circuit board on which the electronic components are mounted to a high temperature of 200 to 300 ° C. when soldering, so the electronic components have considerable heat resistance even temporarily. Is required.

(Problem to be Solved by the Invention) When an aluminum electrolytic capacitor is made to be a face bonding type, a method of integrally molding the entire capacitor with an insulating resin to form a square shape like a solid electrolytic capacitor is known. However, this method has disadvantages in that the manufacturing cost is high and reliability is lacking due to the heat applied during molding.

Therefore, the present applicant has studied a method of putting the capacitor body into a rectangular cylindrical synthetic resin case. Although it is preferable to provide a space between the outer case and the capacitor body in order to improve heat resistance, there is a problem in the body for fixing the capacitor body. That is, in order to fix the capacitor body to the outer case, it was necessary to use an adhesive or the like or to bend the lead wire toward the capacitor body side and press down the outer case.

The present invention has been made in view of the above problems,
An object of the present invention is to provide an electrolytic capacitor in which the outer case and the capacitor body can be easily fixed and the manufacturing cost is low.

(Means for Solving the Problems) In the electrolytic capacitor according to the present invention, a lead wire extends from an end face of the capacitor body, and a connection portion of the lead wire to the substrate is substantially the same as a bottom surface of an outer case made of an insulating resin. In the horizontal electrolytic capacitor bent so as to come on the surface of the outer case, the outer case is formed in a cylindrical shape whose inner shape in cross section is different from the outer shape in cross section of the capacitor body, and a convex portion is formed on the inner surface. Is formed, the capacitor body contains a capacitor element impregnated with an electrolytic solution in an aluminum case, and the lead wire of the capacitor element penetrates through an elastic sealing body arranged at the mouth of the case to form an external part. And the case is squeezed from the outside of the elastic sealing body, so that the capacitor element is sealed in the case and a concave horizontal squeezed portion is formed at the portion of the case. The capacitor body is inserted into the outer case from one end side to form a space between the outer peripheral wall surface and the inner surface of the outer case, and the convex portion formed on the inner surface of the outer case has the concave shape. It is characterized in that it is fixed in the outer case by fitting to the horizontal drawing portion.

It is preferable that the projection is formed on an elastic tongue so that the elastic force of the tongue fits into the horizontal drawing portion of the capacitor body.

(Operation) Since the outer case is formed in a cylindrical shape whose inner shape in cross section is different from the outer shape in cross section of the capacitor main body, a space is formed between the inner surface of the outer case and the outer peripheral wall surface of the capacitor main body. Heat applied from the outside during soldering or the like can be easily blocked, and the reliability of the capacitor body can be maintained.

The fixing of the capacitor body in the outer case formed in a cylindrical shape is performed by squeezing the convex portion formed on the inner surface of the outer case from the outside in order to fix the elastic sealing body to the case opening, and forming a concave side. Since it is fitted and fixed to the aperture part, there is no need to form a separate concave part, the capacitor body can be fixed securely at low cost, and the horizontal aperture part in the middle of the capacitor body can be used. Thus, the size of the entire electrolytic capacitor can be prevented.

In particular, by providing the convex portion on the elastic tongue and fitting the convex to the horizontal drawing portion by the elastic force of the elastic tongue, the capacitor body can be more securely fixed in the outer case.

(Embodiment) Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a sectional view of the electrolytic capacitor 10, and FIG. 2 is a perspective view of the electrolytic capacitor 10 as viewed from the bottom side.

The capacitor body 12 accommodates a capacitor element 14 impregnated with an electrolyte in an aluminum case 16,
The capacitor element 14 is hermetically sealed in the case 16 by disposing an elastic sealing body 18 at the opening of the case and squeezing and fixing the case 16 from the outside of the elastic sealing body 18. 20
Reference numerals a and 20b denote lead wires penetrating from the capacitor element 14 to the outside through the elastic sealing body 18.

The capacitor body 12 is inserted into the outer case 22.

The outer case 22 is formed in a cylindrical shape from a heat-resistant synthetic resin such as polyphenylene alphaide. In the illustrated example, the inner shape is formed as a cavity having an octagonal cross section, and the outer shape is formed as a quadrangular prism. Thus, a space is formed between the outer wall surface of the capacitor body 12 and the inner surface of the outer case 22 at a position corresponding to the inner corner of the outer case 22. In general, air has lower thermal conductivity than synthetic resin. Therefore, such as when soldering
Even if the ambient temperature increases, the presence of the space prevents the heat from being easily transferred to the capacitor body 12 and thus improves the heat resistance.

As shown in FIG. 2, a U-shaped through groove 24 is formed in the outer case 22 to form a tongue piece 26, and the tip of the tongue piece 26 projects inward from the inner surface of the outer case 22. A convex portion 28 is formed, and the convex portion 28 fits and elastically contacts the horizontal drawing portion 30 of the capacitor body 12. As a result, the capacitor body 12 is fixed in the outer case 22 and is prevented from coming off.

The capacitor body 12 may be pushed into the outer case 22 against the elastic force of the tongue piece 26.

A notch 32 is formed at a corner of the mounting surface A of the outer case 22 such as a substrate.
Are formed, and the ends of the lead wires 22a, 22b are bent and located in the notch 32, and the connection portions of the lead wires 22a, 22b to the substrate or the like are substantially flush with the mounting surface A. I have. This allows the electrolytic capacitor 10 to be mounted horizontally on a substrate or the like. The lead wires 20a and 20b may be drawn out to the front side of the outer case 22.

FIG. 3 is a sectional view of a molding die when the outer case 22 is manufactured by injection molding or the like.

As illustrated, a U-shaped projecting wall 34 for forming the through groove 24 is formed on the inner wall surfaces of the outer dies 33, 33. The inner dies 35a and 35b are formed as split molds that open in the left-right direction, and straddle the ends of both the inner dies 35a and 35b to form concave portions 36a and 36b for forming the convex portions 28.

The outer case 22 can be easily and inexpensively manufactured by the molding die.

The numbers of tongue pieces and protrusions are not particularly limited. Further, if the convex portion is formed at a low height that does not hinder the pushing of the capacitor body 12 into the outer case 22, the tongue piece does not necessarily have to be provided.

In the above embodiment, the outer case 22 is made of polyphenylene sulfide. However, since this resin is hard, another heat-resistant resin having more elasticity may be used.

The inner shape of the outer case 22 is octagonal in cross section in the above embodiment, but is not particularly limited. However, as described above, in order to improve heat resistance, a predetermined space is formed between the capacitor body 12 and the outer wall surface. Although the outer shape of the outer case 22 is not particularly limited, it is preferable that the mounting surface A is a flat surface that can be mounted on a substrate or the like.
It is preferable that at least a part of the surface of the outer case 22 opposite to the mounting surface A be flat in order to suck the electrolytic capacitor 10 with a suction cup or the like.

(Effects of the Invention) As described above, according to the present invention, the outer case is formed in a cylindrical shape whose inner shape in cross section is different from the outer shape in cross section of the capacitor body, and the inner surface of the outer case and the outer peripheral wall surface of the capacitor body are formed. In the case of an electrolytic capacitor, a space is formed between the external case and the external heat applied during soldering of the lead wires, etc., and the reliability of the capacitor body is maintained to maintain the reliability of the capacitor body. In order to fix the capacitor body at the opening of the case, the convex part formed on the inner surface of the outer case is fitted and fixed to the concave horizontal drawing part formed by squeezing the case from the outside to fix the elastic sealing body at the case mouth. Therefore, it is not necessary to form a separate concave part, the capacitor body can be fixed securely at low cost, and the entire electrolytic capacitor can be fixed by using the horizontal drawing part in the middle of the capacitor body. Enlargement can also be prevented.

In particular, by providing the convex portion on the elastic tongue and fitting the convex portion to the horizontal drawing portion by the elastic force of the elastic tongue, a remarkable effect that the capacitor body can be more securely fixed in the outer case can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view of an electrolytic capacitor, and FIG. 2 is a perspective view thereof. FIG. 3 is a cross-sectional view showing one example of an outer case molding die. 10 …… Electrolytic capacitor, 12 …… Capacitor body, 16 ……
Case, 18 ... elastic sealing body, 26 ... tongue piece, 28 ... convex part,
30 ... Horizontal draw section.

Claims (2)

(57) [Scope of request for utility model registration] 1. A horizontal type wherein a lead wire extends from an end face of a capacitor body and is bent so that a connection portion of the lead wire to a substrate is substantially flush with a bottom surface of an outer case made of insulating resin. In the electrolytic capacitor, the outer case is formed in a tubular shape whose inner shape in cross section is different from the outer shape in cross section of the capacitor main body, and a convex portion is formed on an inner surface, and the capacitor main body is made of aluminum. A capacitor element impregnated with an electrolytic solution is stored in the case, and the lead wire of the capacitor element is pulled out to the outside through an elastic sealing body arranged at the mouth of the case, and the case is pulled out of the elastic sealing body. By being squeezed, the capacitor element is hermetically sealed in the case, and a concave horizontal squeezed portion is formed at the portion of the case. A space is formed between the outer peripheral wall surface and the inner surface of the outer case by being inserted into the outer case from one end side, and the convex portion formed on the inner surface of the outer case is fitted into the concave horizontal drawing portion so that the outer case is formed. An electrolytic capacitor fixed inside. 2. A through-groove is formed around the convex portion of the outer case, and the projecting portion is located on the tongue. The convex portion is formed on the concave lateral drawing portion on the outer peripheral wall surface of the capacitor body by the elastic force of the tongue. The electrolytic capacitor according to claim 1, wherein the electrolytic capacitor is fitted.